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The new preemtible kmap_local() implementation: 

- Consolidate all kmap_atomic() internals into a generic implementation
     which builds the base for the kmap_local() API and make the
     kmap_atomic() interface wrappers which handle the disabling/enabling of
     preemption and pagefaults.
 
   - Switch the storage from per-CPU to per task and provide scheduler
     support for clearing mapping when scheduling out and restoring them
     when scheduling back in.
 
   - Merge the migrate_disable/enable() code, which is also part of the
     scheduler pull request. This was required to make the kmap_local()
     interface available which does not disable preemption when a mapping
     is established. It has to disable migration instead to guarantee that
     the virtual address of the mapped slot is the same accross preemption.
 
   - Provide better debug facilities: guard pages and enforced utilization
     of the mapping mechanics on 64bit systems when the architecture allows
     it.
 
   - Provide the new kmap_local() API which can now be used to cleanup the
     kmap_atomic() usage sites all over the place. Most of the usage sites
     do not require the implicit disabling of preemption and pagefaults so
     the penalty on 64bit and 32bit non-highmem systems is removed and quite
     some of the code can be simplified. A wholesale conversion is not
     possible because some usage depends on the implicit side effects and
     some need to be cleaned up because they work around these side effects.
 
     The migrate disable side effect is only effective on highmem systems
     and when enforced debugging is enabled. On 64bit and 32bit non-highmem
     systems the overhead is completely avoided.
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Merge tag 'core-mm-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull kmap updates from Thomas Gleixner:
 "The new preemtible kmap_local() implementation:

   - Consolidate all kmap_atomic() internals into a generic
     implementation which builds the base for the kmap_local() API and
     make the kmap_atomic() interface wrappers which handle the
     disabling/enabling of preemption and pagefaults.

   - Switch the storage from per-CPU to per task and provide scheduler
     support for clearing mapping when scheduling out and restoring them
     when scheduling back in.

   - Merge the migrate_disable/enable() code, which is also part of the
     scheduler pull request. This was required to make the kmap_local()
     interface available which does not disable preemption when a
     mapping is established. It has to disable migration instead to
     guarantee that the virtual address of the mapped slot is the same
     across preemption.

   - Provide better debug facilities: guard pages and enforced
     utilization of the mapping mechanics on 64bit systems when the
     architecture allows it.

   - Provide the new kmap_local() API which can now be used to cleanup
     the kmap_atomic() usage sites all over the place. Most of the usage
     sites do not require the implicit disabling of preemption and
     pagefaults so the penalty on 64bit and 32bit non-highmem systems is
     removed and quite some of the code can be simplified. A wholesale
     conversion is not possible because some usage depends on the
     implicit side effects and some need to be cleaned up because they
     work around these side effects.

     The migrate disable side effect is only effective on highmem
     systems and when enforced debugging is enabled. On 64bit and 32bit
     non-highmem systems the overhead is completely avoided"

* tag 'core-mm-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  ARM: highmem: Fix cache_is_vivt() reference
  x86/crashdump/32: Simplify copy_oldmem_page()
  io-mapping: Provide iomap_local variant
  mm/highmem: Provide kmap_local*
  sched: highmem: Store local kmaps in task struct
  x86: Support kmap_local() forced debugging
  mm/highmem: Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
  mm/highmem: Provide and use CONFIG_DEBUG_KMAP_LOCAL
  microblaze/mm/highmem: Add dropped #ifdef back
  xtensa/mm/highmem: Make generic kmap_atomic() work correctly
  mm/highmem: Take kmap_high_get() properly into account
  highmem: High implementation details and document API
  Documentation/io-mapping: Remove outdated blurb
  io-mapping: Cleanup atomic iomap
  mm/highmem: Remove the old kmap_atomic cruft
  highmem: Get rid of kmap_types.h
  xtensa/mm/highmem: Switch to generic kmap atomic
  sparc/mm/highmem: Switch to generic kmap atomic
  powerpc/mm/highmem: Switch to generic kmap atomic
  nds32/mm/highmem: Switch to generic kmap atomic
  ...
This commit is contained in:
Linus Torvalds 2020-12-14 18:35:53 -08:00
parent adb35e8dc9 68061c02bb
commit edd7ab7684
88 changed files with 955 additions and 1432 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

96
Documentation/driver-api/io-mapping.rst
View File

@ -20,78 +20,72 @@ A mapping object is created during driver initialization using::
mappable, while 'size' indicates how large a mapping region to
enable. Both are in bytes.
This _wc variant provides a mapping which may only be used
with the io_mapping_map_atomic_wc or io_mapping_map_wc.
This _wc variant provides a mapping which may only be used with
io_mapping_map_atomic_wc(), io_mapping_map_local_wc() or
io_mapping_map_wc().
With this mapping object, individual pages can be mapped either atomically
or not, depending on the necessary scheduling environment. Of course, atomic
maps are more efficient::
With this mapping object, individual pages can be mapped either temporarily
or long term, depending on the requirements. Of course, temporary maps are
more efficient. They come in two flavours::
void *io_mapping_map_local_wc(struct io_mapping *mapping,
unsigned long offset)
void *io_mapping_map_atomic_wc(struct io_mapping *mapping,
unsigned long offset)
'offset' is the offset within the defined mapping region.
Accessing addresses beyond the region specified in the
creation function yields undefined results. Using an offset
which is not page aligned yields an undefined result. The
return value points to a single page in CPU address space.
'offset' is the offset within the defined mapping region. Accessing
addresses beyond the region specified in the creation function yields
undefined results. Using an offset which is not page aligned yields an
undefined result. The return value points to a single page in CPU address
space.
This _wc variant returns a write-combining map to the
page and may only be used with mappings created by
io_mapping_create_wc
This _wc variant returns a write-combining map to the page and may only be
used with mappings created by io_mapping_create_wc()
Note that the task may not sleep while holding this page
mapped.
Temporary mappings are only valid in the context of the caller. The mapping
is not guaranteed to be globaly visible.
::
io_mapping_map_local_wc() has a side effect on X86 32bit as it disables
migration to make the mapping code work. No caller can rely on this side
effect.
io_mapping_map_atomic_wc() has the side effect of disabling preemption and
pagefaults. Don't use in new code. Use io_mapping_map_local_wc() instead.
Nested mappings need to be undone in reverse order because the mapping
code uses a stack for keeping track of them::
addr1 = io_mapping_map_local_wc(map1, offset1);
addr2 = io_mapping_map_local_wc(map2, offset2);
...
io_mapping_unmap_local(addr2);
io_mapping_unmap_local(addr1);
The mappings are released with::
void io_mapping_unmap_local(void *vaddr)
void io_mapping_unmap_atomic(void *vaddr)
'vaddr' must be the value returned by the last
io_mapping_map_atomic_wc call. This unmaps the specified
page and allows the task to sleep once again.
'vaddr' must be the value returned by the last io_mapping_map_local_wc() or
io_mapping_map_atomic_wc() call. This unmaps the specified mapping and
undoes the side effects of the mapping functions.
If you need to sleep while holding the lock, you can use the non-atomic
variant, although they may be significantly slower.
::
If you need to sleep while holding a mapping, you can use the regular
variant, although this may be significantly slower::
void *io_mapping_map_wc(struct io_mapping *mapping,
unsigned long offset)
This works like io_mapping_map_atomic_wc except it allows
the task to sleep while holding the page mapped.
This works like io_mapping_map_atomic/local_wc() except it has no side
effects and the pointer is globaly visible.
::
The mappings are released with::
void io_mapping_unmap(void *vaddr)
This works like io_mapping_unmap_atomic, except it is used
for pages mapped with io_mapping_map_wc.
Use for pages mapped with io_mapping_map_wc().
At driver close time, the io_mapping object must be freed::
void io_mapping_free(struct io_mapping *mapping)
Current Implementation
======================
The initial implementation of these functions uses existing mapping
mechanisms and so provides only an abstraction layer and no new
functionality.
On 64-bit processors, io_mapping_create_wc calls ioremap_wc for the whole
range, creating a permanent kernel-visible mapping to the resource. The
map_atomic and map functions add the requested offset to the base of the
virtual address returned by ioremap_wc.
On 32-bit processors with HIGHMEM defined, io_mapping_map_atomic_wc uses
kmap_atomic_pfn to map the specified page in an atomic fashion;
kmap_atomic_pfn isn't really supposed to be used with device pages, but it
provides an efficient mapping for this usage.
On 32-bit processors without HIGHMEM defined, io_mapping_map_atomic_wc and
io_mapping_map_wc both use ioremap_wc, a terribly inefficient function which
performs an IPI to inform all processors about the new mapping. This results
in a significant performance penalty.

15
arch/alpha/include/asm/kmap_types.h
View File

@ -1,15 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_KMAP_TYPES_H
#define _ASM_KMAP_TYPES_H
/* Dummy header just to define km_type. */
#ifdef CONFIG_DEBUG_HIGHMEM
#define __WITH_KM_FENCE
#endif
#include <asm-generic/kmap_types.h>
#undef __WITH_KM_FENCE
#endif

1
arch/arc/Kconfig
View File

@ -507,6 +507,7 @@ config LINUX_RAM_BASE
config HIGHMEM
bool "High Memory Support"
select ARCH_DISCONTIGMEM_ENABLE
select KMAP_LOCAL
help
With ARC 2G:2G address split, only upper 2G is directly addressable by
kernel. Enable this to potentially allow access to rest of 2G and PAE

26
arch/arc/include/asm/highmem.h
View File

@ -9,17 +9,29 @@
#ifdef CONFIG_HIGHMEM
#include <uapi/asm/page.h>
#include <asm/kmap_types.h>
#include <asm/kmap_size.h>
#define FIXMAP_SIZE PGDIR_SIZE
#define PKMAP_SIZE PGDIR_SIZE
/* start after vmalloc area */
#define FIXMAP_BASE (PAGE_OFFSET - FIXMAP_SIZE - PKMAP_SIZE)
#define FIXMAP_SIZE PGDIR_SIZE /* only 1 PGD worth */
#define KM_TYPE_NR ((FIXMAP_SIZE >> PAGE_SHIFT)/NR_CPUS)
#define FIXMAP_ADDR(nr) (FIXMAP_BASE + ((nr) << PAGE_SHIFT))
#define FIX_KMAP_SLOTS (KM_MAX_IDX * NR_CPUS)
#define FIX_KMAP_BEGIN (0UL)
#define FIX_KMAP_END ((FIX_KMAP_BEGIN + FIX_KMAP_SLOTS) - 1)
#define FIXADDR_TOP (FIXMAP_BASE + (FIX_KMAP_END << PAGE_SHIFT))
/*
* This should be converted to the asm-generic version, but of course this
* is needlessly different from all other architectures. Sigh - tglx
*/
#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
#define __virt_to_fix(x) (((FIXADDR_TOP - ((x) & PAGE_MASK))) >> PAGE_SHIFT)
/* start after fixmap area */
#define PKMAP_BASE (FIXMAP_BASE + FIXMAP_SIZE)
#define PKMAP_SIZE PGDIR_SIZE
#define LAST_PKMAP (PKMAP_SIZE >> PAGE_SHIFT)
#define LAST_PKMAP_MASK (LAST_PKMAP - 1)
#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
@ -29,11 +41,13 @@
extern void kmap_init(void);
#define arch_kmap_local_post_unmap(vaddr) \
local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE)
static inline void flush_cache_kmaps(void)
{
flush_cache_all();
}
#endif
#endif

14
arch/arc/include/asm/kmap_types.h
View File

@ -1,14 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2015 Synopsys, Inc. (www.synopsys.com)
*/
#ifndef _ASM_KMAP_TYPES_H
#define _ASM_KMAP_TYPES_H
/*
* We primarily need to define KM_TYPE_NR here but that in turn
* is a function of PGDIR_SIZE etc.
* To avoid circular deps issue, put everything in asm/highmem.h
*/
#endif

56
arch/arc/mm/highmem.c
View File

@ -36,9 +36,8 @@
* This means each only has 1 PGDIR_SIZE worth of kvaddr mappings, which means
* 2M of kvaddr space for typical config (8K page and 11:8:13 traversal split)
*
* - fixmap anyhow needs a limited number of mappings. So 2M kvaddr == 256 PTE
* slots across NR_CPUS would be more than sufficient (generic code defines
* KM_TYPE_NR as 20).
* - The fixed KMAP slots for kmap_local/atomic() require KM_MAX_IDX slots per
* CPU. So the number of CPUs sharing a single PTE page is limited.
*
* - pkmap being preemptible, in theory could do with more than 256 concurrent
* mappings. However, generic pkmap code: map_new_virtual(), doesn't traverse
@ -47,48 +46,6 @@
*/
extern pte_t * pkmap_page_table;
static pte_t * fixmap_page_table;
void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
{
int idx, cpu_idx;
unsigned long vaddr;
cpu_idx = kmap_atomic_idx_push();
idx = cpu_idx + KM_TYPE_NR * smp_processor_id();
vaddr = FIXMAP_ADDR(idx);
set_pte_at(&init_mm, vaddr, fixmap_page_table + idx,
mk_pte(page, prot));
return (void *)vaddr;
}
EXPORT_SYMBOL(kmap_atomic_high_prot);
void kunmap_atomic_high(void *kv)
{
unsigned long kvaddr = (unsigned long)kv;
if (kvaddr >= FIXMAP_BASE && kvaddr < (FIXMAP_BASE + FIXMAP_SIZE)) {
/*
* Because preemption is disabled, this vaddr can be associated
* with the current allocated index.
* But in case of multiple live kmap_atomic(), it still relies on
* callers to unmap in right order.
*/
int cpu_idx = kmap_atomic_idx();
int idx = cpu_idx + KM_TYPE_NR * smp_processor_id();
WARN_ON(kvaddr != FIXMAP_ADDR(idx));
pte_clear(&init_mm, kvaddr, fixmap_page_table + idx);
local_flush_tlb_kernel_range(kvaddr, kvaddr + PAGE_SIZE);
kmap_atomic_idx_pop();
}
}
EXPORT_SYMBOL(kunmap_atomic_high);
static noinline pte_t * __init alloc_kmap_pgtable(unsigned long kvaddr)
{
@ -108,10 +65,9 @@ void __init kmap_init(void)
{
/* Due to recursive include hell, we can't do this in processor.h */
BUILD_BUG_ON(PAGE_OFFSET < (VMALLOC_END + FIXMAP_SIZE + PKMAP_SIZE));
BUILD_BUG_ON(KM_TYPE_NR > PTRS_PER_PTE);
pkmap_page_table = alloc_kmap_pgtable(PKMAP_BASE);
BUILD_BUG_ON(LAST_PKMAP > PTRS_PER_PTE);
fixmap_page_table = alloc_kmap_pgtable(FIXMAP_BASE);
BUILD_BUG_ON(FIX_KMAP_SLOTS > PTRS_PER_PTE);
pkmap_page_table = alloc_kmap_pgtable(PKMAP_BASE);
alloc_kmap_pgtable(FIXMAP_BASE);
}

1
arch/arm/Kconfig
View File

@ -1499,6 +1499,7 @@ config HAVE_ARCH_PFN_VALID
config HIGHMEM
bool "High Memory Support"
depends on MMU
select KMAP_LOCAL
help
The address space of ARM processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address

4
arch/arm/include/asm/fixmap.h
View File

@ -7,14 +7,14 @@
#define FIXADDR_TOP (FIXADDR_END - PAGE_SIZE)
#include <linux/pgtable.h>
#include <asm/kmap_types.h>
#include <asm/kmap_size.h>
enum fixed_addresses {
FIX_EARLYCON_MEM_BASE,
__end_of_permanent_fixed_addresses,
FIX_KMAP_BEGIN = __end_of_permanent_fixed_addresses,
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
/* Support writing RO kernel text via kprobes, jump labels, etc. */
FIX_TEXT_POKE0,

34
arch/arm/include/asm/highmem.h
View File

@ -2,7 +2,8 @@
#ifndef _ASM_HIGHMEM_H
#define _ASM_HIGHMEM_H
#include <asm/kmap_types.h>
#include <asm/cachetype.h>
#include <asm/fixmap.h>
#define PKMAP_BASE (PAGE_OFFSET - PMD_SIZE)
#define LAST_PKMAP PTRS_PER_PTE
@ -46,19 +47,32 @@ extern pte_t *pkmap_page_table;
#ifdef ARCH_NEEDS_KMAP_HIGH_GET
extern void *kmap_high_get(struct page *page);
#else
static inline void *arch_kmap_local_high_get(struct page *page)
{
if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !cache_is_vivt())
return NULL;
return kmap_high_get(page);
}
#define arch_kmap_local_high_get arch_kmap_local_high_get
#else /* ARCH_NEEDS_KMAP_HIGH_GET */
static inline void *kmap_high_get(struct page *page)
{
return NULL;
}
#endif
#endif /* !ARCH_NEEDS_KMAP_HIGH_GET */
/*
* The following functions are already defined by <linux/highmem.h>
* when CONFIG_HIGHMEM is not set.
*/
#ifdef CONFIG_HIGHMEM
extern void *kmap_atomic_pfn(unsigned long pfn);
#endif
#define arch_kmap_local_post_map(vaddr, pteval) \
local_flush_tlb_kernel_page(vaddr)
#define arch_kmap_local_pre_unmap(vaddr) \
do { \
if (cache_is_vivt()) \
__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); \
} while (0)
#define arch_kmap_local_post_unmap(vaddr) \
local_flush_tlb_kernel_page(vaddr)
#endif

10
arch/arm/include/asm/kmap_types.h
View File

@ -1,10 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ARM_KMAP_TYPES_H
#define __ARM_KMAP_TYPES_H
/*
* This is the "bare minimum". AIO seems to require this.
*/
#define KM_TYPE_NR 16
#endif

1
arch/arm/mm/Makefile
View File

@ -19,7 +19,6 @@ obj-$(CONFIG_MODULES) += proc-syms.o
obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o
obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o
obj-$(CONFIG_HIGHMEM) += highmem.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_ARM_PV_FIXUP) += pv-fixup-asm.o

121
arch/arm/mm/highmem.c
View File

@ -1,121 +0,0 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* arch/arm/mm/highmem.c -- ARM highmem support
*
* Author: Nicolas Pitre
* Created: september 8, 2008
* Copyright: Marvell Semiconductors Inc.
*/
#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/interrupt.h>
#include <asm/fixmap.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include "mm.h"
static inline void set_fixmap_pte(int idx, pte_t pte)
{
unsigned long vaddr = __fix_to_virt(idx);
pte_t *ptep = virt_to_kpte(vaddr);
set_pte_ext(ptep, pte, 0);
local_flush_tlb_kernel_page(vaddr);
}
static inline pte_t get_fixmap_pte(unsigned long vaddr)
{
pte_t *ptep = virt_to_kpte(vaddr);
return *ptep;
}
void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
{
unsigned int idx;
unsigned long vaddr;
void *kmap;
int type;
#ifdef CONFIG_DEBUG_HIGHMEM
/*
* There is no cache coherency issue when non VIVT, so force the
* dedicated kmap usage for better debugging purposes in that case.
*/
if (!cache_is_vivt())
kmap = NULL;
else
#endif
kmap = kmap_high_get(page);
if (kmap)
return kmap;
type = kmap_atomic_idx_push();
idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(idx);
#ifdef CONFIG_DEBUG_HIGHMEM
/*
* With debugging enabled, kunmap_atomic forces that entry to 0.
* Make sure it was indeed properly unmapped.
*/
BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
#endif
/*
* When debugging is off, kunmap_atomic leaves the previous mapping
* in place, so the contained TLB flush ensures the TLB is updated
* with the new mapping.
*/
set_fixmap_pte(idx, mk_pte(page, prot));
return (void *)vaddr;
}
EXPORT_SYMBOL(kmap_atomic_high_prot);
void kunmap_atomic_high(void *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
int idx, type;
if (kvaddr >= (void *)FIXADDR_START) {
type = kmap_atomic_idx();
idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
if (cache_is_vivt())
__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(vaddr != __fix_to_virt(idx));
set_fixmap_pte(idx, __pte(0));
#else
(void) idx; /* to kill a warning */
#endif
kmap_atomic_idx_pop();
} else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
/* this address was obtained through kmap_high_get() */
kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
}
}
EXPORT_SYMBOL(kunmap_atomic_high);
void *kmap_atomic_pfn(unsigned long pfn)
{
unsigned long vaddr;
int idx, type;
struct page *page = pfn_to_page(pfn);
preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
type = kmap_atomic_idx_push();
idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(idx);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
#endif
set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot));
return (void *)vaddr;
}

1
arch/csky/Kconfig
View File

@ -286,6 +286,7 @@ config NR_CPUS
config HIGHMEM
bool "High Memory Support"
depends on !CPU_CK610
select KMAP_LOCAL
default y
config FORCE_MAX_ZONEORDER

4
arch/csky/include/asm/fixmap.h
View File

@ -8,7 +8,7 @@
#include <asm/memory.h>
#ifdef CONFIG_HIGHMEM
#include <linux/threads.h>
#include <asm/kmap_types.h>
#include <asm/kmap_size.h>
#endif
enum fixed_addresses {
@ -17,7 +17,7 @@ enum fixed_addresses {
#endif
#ifdef CONFIG_HIGHMEM
FIX_KMAP_BEGIN,
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
#endif
__end_of_fixed_addresses
};

6
arch/csky/include/asm/highmem.h
View File

@ -9,7 +9,7 @@
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/uaccess.h>
#include <asm/kmap_types.h>
#include <asm/kmap_size.h>
#include <asm/cache.h>
/* undef for production */
@ -32,10 +32,12 @@ extern pte_t *pkmap_page_table;
#define ARCH_HAS_KMAP_FLUSH_TLB
extern void kmap_flush_tlb(unsigned long addr);
extern void *kmap_atomic_pfn(unsigned long pfn);
#define flush_cache_kmaps() do {} while (0)
#define arch_kmap_local_post_map(vaddr, pteval) kmap_flush_tlb(vaddr)
#define arch_kmap_local_post_unmap(vaddr) kmap_flush_tlb(vaddr)
extern void kmap_init(void);
#endif /* __KERNEL__ */

75
arch/csky/mm/highmem.c
View File

@ -9,8 +9,6 @@
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
static pte_t *kmap_pte;
unsigned long highstart_pfn, highend_pfn;
void kmap_flush_tlb(unsigned long addr)
@ -19,67 +17,7 @@ void kmap_flush_tlb(unsigned long addr)
}
EXPORT_SYMBOL(kmap_flush_tlb);
void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
{
unsigned long vaddr;
int idx, type;
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(*(kmap_pte - idx)));
#endif
set_pte(kmap_pte-idx, mk_pte(page, prot));
flush_tlb_one((unsigned long)vaddr);
return (void *)vaddr;
}
EXPORT_SYMBOL(kmap_atomic_high_prot);
void kunmap_atomic_high(void *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
int idx;
if (vaddr < FIXADDR_START)
return;
#ifdef CONFIG_DEBUG_HIGHMEM
idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
pte_clear(&init_mm, vaddr, kmap_pte - idx);
flush_tlb_one(vaddr);
#else
(void) idx; /* to kill a warning */
#endif
kmap_atomic_idx_pop();
}
EXPORT_SYMBOL(kunmap_atomic_high);
/*
* This is the same as kmap_atomic() but can map memory that doesn't
* have a struct page associated with it.
*/
void *kmap_atomic_pfn(unsigned long pfn)
{
unsigned long vaddr;
int idx, type;
pagefault_disable();
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
flush_tlb_one(vaddr);
return (void *) vaddr;
}
static void __init kmap_pages_init(void)
void __init kmap_init(void)
{
unsigned long vaddr;
pgd_t *pgd;
@ -96,14 +34,3 @@ static void __init kmap_pages_init(void)
pte = pte_offset_kernel(pmd, vaddr);
pkmap_page_table = pte;
}
void __init kmap_init(void)
{
unsigned long vaddr;
kmap_pages_init();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN);
kmap_pte = pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr);
}

13
arch/ia64/include/asm/kmap_types.h
View File

@ -1,13 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_IA64_KMAP_TYPES_H
#define _ASM_IA64_KMAP_TYPES_H
#ifdef CONFIG_DEBUG_HIGHMEM
#define __WITH_KM_FENCE
#endif
#include <asm-generic/kmap_types.h>
#undef __WITH_KM_FENCE
#endif /* _ASM_IA64_KMAP_TYPES_H */

1
arch/microblaze/Kconfig
View File

@ -155,6 +155,7 @@ config XILINX_UNCACHED_SHADOW
config HIGHMEM
bool "High memory support"
depends on MMU
select KMAP_LOCAL
help
The address space of Microblaze processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address

4
arch/microblaze/include/asm/fixmap.h
View File

@ -20,7 +20,7 @@
#include <asm/page.h>
#ifdef CONFIG_HIGHMEM
#include <linux/threads.h>
#include <asm/kmap_types.h>
#include <asm/kmap_size.h>
#endif
#define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE))
@ -47,7 +47,7 @@ enum fixed_addresses {
FIX_HOLE,
#ifdef CONFIG_HIGHMEM
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * num_possible_cpus()) - 1,
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * num_possible_cpus()) - 1,
#endif
__end_of_fixed_addresses
};

6
arch/microblaze/include/asm/highmem.h
View File

@ -25,7 +25,6 @@
#include <linux/uaccess.h>
#include <asm/fixmap.h>
extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
/*
@ -52,6 +51,11 @@ extern pte_t *pkmap_page_table;
#define flush_cache_kmaps() { flush_icache(); flush_dcache(); }
#define arch_kmap_local_post_map(vaddr, pteval) \
local_flush_tlb_page(NULL, vaddr);
#define arch_kmap_local_post_unmap(vaddr) \
local_flush_tlb_page(NULL, vaddr);
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */

1
arch/microblaze/mm/Makefile
View File

@ -6,4 +6,3 @@
obj-y := consistent.o init.o
obj-$(CONFIG_MMU) += pgtable.o mmu_context.o fault.o
obj-$(CONFIG_HIGHMEM) += highmem.o

78
arch/microblaze/mm/highmem.c
View File

@ -1,78 +0,0 @@
// SPDX-License-Identifier: GPL-2.0
/*
* highmem.c: virtual kernel memory mappings for high memory
*
* PowerPC version, stolen from the i386 version.
*
* Used in CONFIG_HIGHMEM systems for memory pages which
* are not addressable by direct kernel virtual addresses.
*
* Copyright (C) 1999 Gerhard Wichert, Siemens AG
* Gerhard.Wichert@pdb.siemens.de
*
*
* Redesigned the x86 32-bit VM architecture to deal with
* up to 16 Terrabyte physical memory. With current x86 CPUs
* we now support up to 64 Gigabytes physical RAM.
*
* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
*
* Reworked for PowerPC by various contributors. Moved from
* highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
*/
#include <linux/export.h>
#include <linux/highmem.h>
/*
* The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
* gives a more generic (and caching) interface. But kmap_atomic can
* be used in IRQ contexts, so in some (very limited) cases we need
* it.
*/
#include <asm/tlbflush.h>
void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
{
unsigned long vaddr;
int idx, type;
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(*(kmap_pte-idx)));
#endif
set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
local_flush_tlb_page(NULL, vaddr);
return (void *) vaddr;
}
EXPORT_SYMBOL(kmap_atomic_high_prot);
void kunmap_atomic_high(void *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
int type;
unsigned int idx;
if (vaddr < __fix_to_virt(FIX_KMAP_END))
return;
type = kmap_atomic_idx();
idx = type + KM_TYPE_NR * smp_processor_id();
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
#endif
/*
* force other mappings to Oops if they'll try to access
* this pte without first remap it
*/
pte_clear(&init_mm, vaddr, kmap_pte-idx);
local_flush_tlb_page(NULL, vaddr);
kmap_atomic_idx_pop();
}
EXPORT_SYMBOL(kunmap_atomic_high);

5
arch/microblaze/mm/init.c
View File

@ -50,16 +50,11 @@ EXPORT_SYMBOL(min_low_pfn);
EXPORT_SYMBOL(max_low_pfn);
#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
EXPORT_SYMBOL(kmap_pte);
static void __init highmem_init(void)
{
pr_debug("%x\n", (u32)PKMAP_BASE);
map_page(PKMAP_BASE, 0, 0); /* XXX gross */
pkmap_page_table = virt_to_kpte(PKMAP_BASE);
kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
}
static void highmem_setup(void)

1
arch/mips/Kconfig
View File

@ -2719,6 +2719,7 @@ config WAR_MIPS34K_MISSED_ITLB
config HIGHMEM
bool "High Memory Support"
depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM && !CPU_MIPS32_3_5_EVA
select KMAP_LOCAL
config CPU_SUPPORTS_HIGHMEM
bool

4
arch/mips/include/asm/fixmap.h
View File

@ -17,7 +17,7 @@
#include <spaces.h>
#ifdef CONFIG_HIGHMEM
#include <linux/threads.h>
#include <asm/kmap_types.h>
#include <asm/kmap_size.h>
#endif
/*
@ -52,7 +52,7 @@ enum fixed_addresses {
#ifdef CONFIG_HIGHMEM
/* reserved pte's for temporary kernel mappings */
FIX_KMAP_BEGIN = FIX_CMAP_END + 1,
FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
#endif
__end_of_fixed_addresses
};

6
arch/mips/include/asm/highmem.h
View File

@ -24,7 +24,7 @@
#include <linux/interrupt.h>
#include <linux/uaccess.h>
#include <asm/cpu-features.h>
#include <asm/kmap_types.h>
#include <asm/kmap_size.h>
/* declarations for highmem.c */
extern unsigned long highstart_pfn, highend_pfn;
@ -48,11 +48,11 @@ extern pte_t *pkmap_page_table;
#define ARCH_HAS_KMAP_FLUSH_TLB
extern void kmap_flush_tlb(unsigned long addr);
extern void *kmap_atomic_pfn(unsigned long pfn);
#define flush_cache_kmaps() BUG_ON(cpu_has_dc_aliases)
extern void kmap_init(void);
#define arch_kmap_local_post_map(vaddr, pteval) local_flush_tlb_one(vaddr)
#define arch_kmap_local_post_unmap(vaddr) local_flush_tlb_one(vaddr)
#endif /* __KERNEL__ */

13
arch/mips/include/asm/kmap_types.h
View File

@ -1,13 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_KMAP_TYPES_H
#define _ASM_KMAP_TYPES_H
#ifdef CONFIG_DEBUG_HIGHMEM
#define __WITH_KM_FENCE
#endif
#include <asm-generic/kmap_types.h>
#undef __WITH_KM_FENCE
#endif

77
arch/mips/mm/highmem.c
View File

@ -8,8 +8,6 @@
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
static pte_t *kmap_pte;
unsigned long highstart_pfn, highend_pfn;
void kmap_flush_tlb(unsigned long addr)
@ -17,78 +15,3 @@ void kmap_flush_tlb(unsigned long addr)
flush_tlb_one(addr);
}
EXPORT_SYMBOL(kmap_flush_tlb);
void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
{
unsigned long vaddr;
int idx, type;
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(*(kmap_pte - idx)));
#endif
set_pte(kmap_pte-idx, mk_pte(page, prot));
local_flush_tlb_one((unsigned long)vaddr);
return (void*) vaddr;
}
EXPORT_SYMBOL(kmap_atomic_high_prot);
void kunmap_atomic_high(void *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
int type __maybe_unused;
if (vaddr < FIXADDR_START)
return;
type = kmap_atomic_idx();
#ifdef CONFIG_DEBUG_HIGHMEM
{
int idx = type + KM_TYPE_NR * smp_processor_id();
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
/*
* force other mappings to Oops if they'll try to access
* this pte without first remap it
*/
pte_clear(&init_mm, vaddr, kmap_pte-idx);
local_flush_tlb_one(vaddr);
}
#endif
kmap_atomic_idx_pop();
}
EXPORT_SYMBOL(kunmap_atomic_high);
/*
* This is the same as kmap_atomic() but can map memory that doesn't
* have a struct page associated with it.
*/
void *kmap_atomic_pfn(unsigned long pfn)
{
unsigned long vaddr;
int idx, type;
preempt_disable();
pagefault_disable();
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
flush_tlb_one(vaddr);
return (void*) vaddr;
}
void __init kmap_init(void)
{
unsigned long kmap_vstart;
/* cache the first kmap pte */
kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
kmap_pte = virt_to_kpte(kmap_vstart);
}

4
arch/mips/mm/init.c
View File

@ -36,7 +36,6 @@
#include <asm/cachectl.h>
#include <asm/cpu.h>
#include <asm/dma.h>
#include <asm/kmap_types.h>
#include <asm/maar.h>
#include <asm/mmu_context.h>
#include <asm/sections.h>
@ -402,9 +401,6 @@ void __init paging_init(void)
pagetable_init();
#ifdef CONFIG_HIGHMEM
kmap_init();
#endif
#ifdef CONFIG_ZONE_DMA
max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
#endif

1
arch/nds32/Kconfig.cpu
View File

@ -157,6 +157,7 @@ config HW_SUPPORT_UNALIGNMENT_ACCESS
config HIGHMEM
bool "High Memory Support"
depends on MMU && !CPU_CACHE_ALIASING
select KMAP_LOCAL
help
The address space of Andes processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address

4
arch/nds32/include/asm/fixmap.h
View File

@ -6,7 +6,7 @@
#ifdef CONFIG_HIGHMEM
#include <linux/threads.h>
#include <asm/kmap_types.h>
#include <asm/kmap_size.h>
#endif
enum fixed_addresses {
@ -14,7 +14,7 @@ enum fixed_addresses {
FIX_KMAP_RESERVED,
FIX_KMAP_BEGIN,
#ifdef CONFIG_HIGHMEM
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS),
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
#endif
FIX_EARLYCON_MEM_BASE,
__end_of_fixed_addresses

22
arch/nds32/include/asm/highmem.h
View File

@ -5,7 +5,6 @@
#define _ASM_HIGHMEM_H
#include <asm/proc-fns.h>
#include <asm/kmap_types.h>
#include <asm/fixmap.h>
/*
@ -45,11 +44,22 @@ extern pte_t *pkmap_page_table;
extern void kmap_init(void);
/*
* The following functions are already defined by <linux/highmem.h>
* when CONFIG_HIGHMEM is not set.
* FIXME: The below looks broken vs. a kmap_atomic() in task context which
* is interupted and another kmap_atomic() happens in interrupt context.
* But what do I know about nds32. -- tglx
*/
#ifdef CONFIG_HIGHMEM
extern void *kmap_atomic_pfn(unsigned long pfn);
#endif
#define arch_kmap_local_post_map(vaddr, pteval) \
do { \
__nds32__tlbop_inv(vaddr); \
__nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN); \
__nds32__tlbop_rwr(pteval); \
__nds32__isb(); \
} while (0)
#define arch_kmap_local_pre_unmap(vaddr) \
do { \
__nds32__tlbop_inv(vaddr); \
__nds32__isb(); \
} while (0)
#endif

1
arch/nds32/mm/Makefile
View File

@ -3,7 +3,6 @@ obj-y := extable.o tlb.o fault.o init.o mmap.o \
mm-nds32.o cacheflush.o proc.o
obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o
obj-$(CONFIG_HIGHMEM) += highmem.o
ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_proc.o = $(CC_FLAGS_FTRACE)

48
arch/nds32/mm/highmem.c
View File

@ -1,48 +0,0 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#include <linux/export.h>
#include <linux/highmem.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/memblock.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
{
unsigned int idx;
unsigned long vaddr, pte;
int type;
pte_t *ptep;
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
pte = (page_to_pfn(page) << PAGE_SHIFT) | prot;
ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
set_pte(ptep, pte);
__nds32__tlbop_inv(vaddr);
__nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN);
__nds32__tlbop_rwr(pte);
__nds32__isb();
return (void *)vaddr;
}
EXPORT_SYMBOL(kmap_atomic_high_prot);
void kunmap_atomic_high(void *kvaddr)
{
if (kvaddr >= (void *)FIXADDR_START) {
unsigned long vaddr = (unsigned long)kvaddr;
pte_t *ptep;
kmap_atomic_idx_pop();
__nds32__tlbop_inv(vaddr);
__nds32__isb();
ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
set_pte(ptep, 0);
}
}
EXPORT_SYMBOL(kunmap_atomic_high);

1
arch/openrisc/mm/init.c
View File

@ -33,7 +33,6 @@
#include <asm/io.h>
#include <asm/tlb.h>
#include <asm/mmu_context.h>
#include <asm/kmap_types.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>

1
arch/openrisc/mm/ioremap.c
View File

@ -15,7 +15,6 @@
#include <linux/io.h>
#include <linux/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/kmap_types.h>
#include <asm/fixmap.h>
#include <asm/bug.h>
#include <linux/sched.h>

13
arch/parisc/include/asm/kmap_types.h
View File

@ -1,13 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_KMAP_TYPES_H
#define _ASM_KMAP_TYPES_H
#ifdef CONFIG_DEBUG_HIGHMEM
#define __WITH_KM_FENCE
#endif
#include <asm-generic/kmap_types.h>
#undef __WITH_KM_FENCE
#endif

1
arch/powerpc/Kconfig
View File

@ -410,6 +410,7 @@ menu "Kernel options"
config HIGHMEM
bool "High memory support"
depends on PPC32
select KMAP_LOCAL
source "kernel/Kconfig.hz"

4
arch/powerpc/include/asm/fixmap.h
View File

@ -20,7 +20,7 @@
#include <asm/page.h>
#ifdef CONFIG_HIGHMEM
#include <linux/threads.h>
#include <asm/kmap_types.h>
#include <asm/kmap_size.h>
#endif
#ifdef CONFIG_KASAN
@ -55,7 +55,7 @@ enum fixed_addresses {
FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+(ALIGN(SZ_128K, PAGE_SIZE)/PAGE_SIZE)-1,
#ifdef CONFIG_HIGHMEM
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
#endif
#ifdef CONFIG_PPC_8xx
/* For IMMR we need an aligned 512K area */

7
arch/powerpc/include/asm/highmem.h
View File

@ -24,12 +24,10 @@
#ifdef __KERNEL__
#include <linux/interrupt.h>
#include <asm/kmap_types.h>
#include <asm/cacheflush.h>
#include <asm/page.h>
#include <asm/fixmap.h>
extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
/*
@ -60,6 +58,11 @@ extern pte_t *pkmap_page_table;
#define flush_cache_kmaps() flush_cache_all()
#define arch_kmap_local_post_map(vaddr, pteval) \
local_flush_tlb_page(NULL, vaddr)
#define arch_kmap_local_post_unmap(vaddr) \
local_flush_tlb_page(NULL, vaddr)
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */

13
arch/powerpc/include/asm/kmap_types.h
View File

@ -1,13 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _ASM_POWERPC_KMAP_TYPES_H
#define _ASM_POWERPC_KMAP_TYPES_H
#ifdef __KERNEL__
/*
*/
#define KM_TYPE_NR 16
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_KMAP_TYPES_H */

1
arch/powerpc/mm/Makefile
View File

@ -16,7 +16,6 @@ obj-$(CONFIG_NEED_MULTIPLE_NODES) += numa.o
obj-$(CONFIG_PPC_MM_SLICES) += slice.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o
obj-$(CONFIG_HIGHMEM) += highmem.o
obj-$(CONFIG_PPC_COPRO_BASE) += copro_fault.o
obj-$(CONFIG_PPC_PTDUMP) += ptdump/
obj-$(CONFIG_KASAN) += kasan/

67
arch/powerpc/mm/highmem.c
View File

@ -1,67 +0,0 @@
// SPDX-License-Identifier: GPL-2.0
/*
* highmem.c: virtual kernel memory mappings for high memory
*
* PowerPC version, stolen from the i386 version.
*
* Used in CONFIG_HIGHMEM systems for memory pages which
* are not addressable by direct kernel virtual addresses.
*
* Copyright (C) 1999 Gerhard Wichert, Siemens AG
* Gerhard.Wichert@pdb.siemens.de
*
*
* Redesigned the x86 32-bit VM architecture to deal with
* up to 16 Terrabyte physical memory. With current x86 CPUs
* we now support up to 64 Gigabytes physical RAM.
*
* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
*
* Reworked for PowerPC by various contributors. Moved from
* highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
*/
#include <linux/highmem.h>
#include <linux/module.h>
void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
{
unsigned long vaddr;
int idx, type;
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
WARN_ON(IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !pte_none(*(kmap_pte - idx)));
__set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot), 1);
local_flush_tlb_page(NULL, vaddr);
return (void*) vaddr;
}
EXPORT_SYMBOL(kmap_atomic_high_prot);
void kunmap_atomic_high(void *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
if (vaddr < __fix_to_virt(FIX_KMAP_END))
return;
if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM)) {
int type = kmap_atomic_idx();
unsigned int idx;
idx = type + KM_TYPE_NR * smp_processor_id();
WARN_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
/*
* force other mappings to Oops if they'll try to access
* this pte without first remap it
*/
pte_clear(&init_mm, vaddr, kmap_pte-idx);
local_flush_tlb_page(NULL, vaddr);
}
kmap_atomic_idx_pop();
}
EXPORT_SYMBOL(kunmap_atomic_high);

7
arch/powerpc/mm/mem.c
View File

@ -62,11 +62,6 @@
unsigned long long memory_limit;
bool init_mem_is_free;
#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
EXPORT_SYMBOL(kmap_pte);
#endif
pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
{
@ -236,8 +231,6 @@ void __init paging_init(void)
map_kernel_page(PKMAP_BASE, 0, __pgprot(0)); /* XXX gross */
pkmap_page_table = virt_to_kpte(PKMAP_BASE);
kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
#endif /* CONFIG_HIGHMEM */
printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",

8
arch/sh/include/asm/fixmap.h
View File

@ -13,9 +13,6 @@
#include <linux/kernel.h>
#include <linux/threads.h>
#include <asm/page.h>
#ifdef CONFIG_HIGHMEM
#include <asm/kmap_types.h>
#endif
/*
* Here we define all the compile-time 'special' virtual
@ -53,11 +50,6 @@ enum fixed_addresses {
FIX_CMAP_BEGIN,
FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * NR_CPUS) - 1,
#ifdef CONFIG_HIGHMEM
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,
#endif
#ifdef CONFIG_IOREMAP_FIXED
/*
* FIX_IOREMAP entries are useful for mapping physical address

15
arch/sh/include/asm/kmap_types.h
View File

@ -1,15 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __SH_KMAP_TYPES_H
#define __SH_KMAP_TYPES_H
/* Dummy header just to define km_type. */
#ifdef CONFIG_DEBUG_HIGHMEM
#define __WITH_KM_FENCE
#endif
#include <asm-generic/kmap_types.h>
#undef __WITH_KM_FENCE
#endif

8
arch/sh/mm/init.c
View File

@ -362,9 +362,6 @@ void __init mem_init(void)
mem_init_print_info(NULL);
pr_info("virtual kernel memory layout:\n"
" fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
#ifdef CONFIG_HIGHMEM
" pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
#endif
" vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
" lowmem : 0x%08lx - 0x%08lx (%4ld MB) (cached)\n"
#ifdef CONFIG_UNCACHED_MAPPING
@ -376,11 +373,6 @@ void __init mem_init(void)
FIXADDR_START, FIXADDR_TOP,
(FIXADDR_TOP - FIXADDR_START) >> 10,
#ifdef CONFIG_HIGHMEM
PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
(LAST_PKMAP*PAGE_SIZE) >> 10,
#endif
(unsigned long)VMALLOC_START, VMALLOC_END,
(VMALLOC_END - VMALLOC_START) >> 20,

1
arch/sparc/Kconfig
View File

@ -139,6 +139,7 @@ config MMU
config HIGHMEM
bool
default y if SPARC32
select KMAP_LOCAL
config ZONE_DMA
bool

8
arch/sparc/include/asm/highmem.h
View File

@ -24,7 +24,6 @@
#include <linux/interrupt.h>
#include <linux/pgtable.h>
#include <asm/vaddrs.h>
#include <asm/kmap_types.h>
#include <asm/pgtsrmmu.h>
/* declarations for highmem.c */
@ -33,8 +32,6 @@ extern unsigned long highstart_pfn, highend_pfn;
#define kmap_prot __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE)
extern pte_t *pkmap_page_table;
void kmap_init(void) __init;
/*
* Right now we initialize only a single pte table. It can be extended
* easily, subsequent pte tables have to be allocated in one physical
@ -53,6 +50,11 @@ void kmap_init(void) __init;
#define flush_cache_kmaps() flush_cache_all()
/* FIXME: Use __flush_tlb_one(vaddr) instead of flush_cache_all() -- Anton */
#define arch_kmap_local_post_map(vaddr, pteval) flush_cache_all()
#define arch_kmap_local_post_unmap(vaddr) flush_cache_all()
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */

11
arch/sparc/include/asm/kmap_types.h
View File

@ -1,11 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_KMAP_TYPES_H
#define _ASM_KMAP_TYPES_H
/* Dummy header just to define km_type. None of this
* is actually used on sparc. -DaveM
*/
#include <asm-generic/kmap_types.h>
#endif

4
arch/sparc/include/asm/vaddrs.h
View File

@ -32,13 +32,13 @@
#define SRMMU_NOCACHE_ALCRATIO 64 /* 256 pages per 64MB of system RAM */
#ifndef __ASSEMBLY__
#include <asm/kmap_types.h>
#include <asm/kmap_size.h>
enum fixed_addresses {
FIX_HOLE,
#ifdef CONFIG_HIGHMEM
FIX_KMAP_BEGIN,
FIX_KMAP_END = (KM_TYPE_NR * NR_CPUS),
FIX_KMAP_END = (KM_MAX_IDX * NR_CPUS),
#endif
__end_of_fixed_addresses
};

3
arch/sparc/mm/Makefile
View File

@ -15,6 +15,3 @@ obj-$(CONFIG_SPARC32) += leon_mm.o
# Only used by sparc64
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
# Only used by sparc32
obj-$(CONFIG_HIGHMEM) += highmem.o

115
arch/sparc/mm/highmem.c
View File

@ -1,115 +0,0 @@
// SPDX-License-Identifier: GPL-2.0
/*
* highmem.c: virtual kernel memory mappings for high memory
*
* Provides kernel-static versions of atomic kmap functions originally
* found as inlines in include/asm-sparc/highmem.h. These became
* needed as kmap_atomic() and kunmap_atomic() started getting
* called from within modules.
* -- Tomas Szepe <szepe@pinerecords.com>, September 2002
*
* But kmap_atomic() and kunmap_atomic() cannot be inlined in
* modules because they are loaded with btfixup-ped functions.
*/
/*
* The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
* gives a more generic (and caching) interface. But kmap_atomic can
* be used in IRQ contexts, so in some (very limited) cases we need it.
*
* XXX This is an old text. Actually, it's good to use atomic kmaps,
* provided you remember that they are atomic and not try to sleep
* with a kmap taken, much like a spinlock. Non-atomic kmaps are
* shared by CPUs, and so precious, and establishing them requires IPI.
* Atomic kmaps are lightweight and we may have NCPUS more of them.
*/
#include <linux/highmem.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/vaddrs.h>
static pte_t *kmap_pte;
void __init kmap_init(void)
{
unsigned long address = __fix_to_virt(FIX_KMAP_BEGIN);
/* cache the first kmap pte */
kmap_pte = virt_to_kpte(address);
}
void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
{
unsigned long vaddr;
long idx, type;
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
/* XXX Fix - Anton */
#if 0
__flush_cache_one(vaddr);
#else
flush_cache_all();
#endif
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(*(kmap_pte-idx)));
#endif
set_pte(kmap_pte-idx, mk_pte(page, prot));
/* XXX Fix - Anton */
#if 0
__flush_tlb_one(vaddr);
#else
flush_tlb_all();
#endif
return (void*) vaddr;
}
EXPORT_SYMBOL(kmap_atomic_high_prot);
void kunmap_atomic_high(void *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
int type;
if (vaddr < FIXADDR_START)
return;
type = kmap_atomic_idx();
#ifdef CONFIG_DEBUG_HIGHMEM
{
unsigned long idx;
idx = type + KM_TYPE_NR * smp_processor_id();
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx));
/* XXX Fix - Anton */
#if 0
__flush_cache_one(vaddr);
#else
flush_cache_all();
#endif
/*
* force other mappings to Oops if they'll try to access
* this pte without first remap it
*/
pte_clear(&init_mm, vaddr, kmap_pte-idx);
/* XXX Fix - Anton */
#if 0
__flush_tlb_one(vaddr);
#else
flush_tlb_all();
#endif
}
#endif
kmap_atomic_idx_pop();
}
EXPORT_SYMBOL(kunmap_atomic_high);

2
arch/sparc/mm/srmmu.c
View File

@ -971,8 +971,6 @@ void __init srmmu_paging_init(void)
sparc_context_init(num_contexts);
kmap_init();
{
unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };

1
arch/um/include/asm/fixmap.h
View File

@ -3,7 +3,6 @@
#define __UM_FIXMAP_H
#include <asm/processor.h>
#include <asm/kmap_types.h>
#include <asm/archparam.h>
#include <asm/page.h>
#include <linux/threads.h>

13
arch/um/include/asm/kmap_types.h
View File

@ -1,13 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
*/
#ifndef __UM_KMAP_TYPES_H
#define __UM_KMAP_TYPES_H
/* No more #include "asm/arch/kmap_types.h" ! */
#define KM_TYPE_NR 14
#endif

4
arch/x86/Kconfig
View File

@ -14,10 +14,11 @@ config X86_32
select ARCH_WANT_IPC_PARSE_VERSION
select CLKSRC_I8253
select CLONE_BACKWARDS
select GENERIC_VDSO_32
select HAVE_DEBUG_STACKOVERFLOW
select KMAP_LOCAL
select MODULES_USE_ELF_REL
select OLD_SIGACTION
select GENERIC_VDSO_32
config X86_64
def_bool y
@ -92,6 +93,7 @@ config X86
select ARCH_SUPPORTS_ACPI
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS

15
arch/x86/include/asm/fixmap.h
View File

@ -14,13 +14,20 @@
#ifndef _ASM_X86_FIXMAP_H
#define _ASM_X86_FIXMAP_H
#include <asm/kmap_size.h>
/*
* Exposed to assembly code for setting up initial page tables. Cannot be
* calculated in assembly code (fixmap entries are an enum), but is sanity
* checked in the actual fixmap C code to make sure that the fixmap is
* covered fully.
*/
#define FIXMAP_PMD_NUM 2
#ifndef CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
# define FIXMAP_PMD_NUM 2
#else
# define KM_PMDS (KM_MAX_IDX * ((CONFIG_NR_CPUS + 511) / 512))
# define FIXMAP_PMD_NUM (KM_PMDS + 2)
#endif
/* fixmap starts downwards from the 507th entry in level2_fixmap_pgt */
#define FIXMAP_PMD_TOP 507
@ -31,7 +38,6 @@
#include <asm/pgtable_types.h>
#ifdef CONFIG_X86_32
#include <linux/threads.h>
#include <asm/kmap_types.h>
#else
#include <uapi/asm/vsyscall.h>
#endif
@ -92,9 +98,9 @@ enum fixed_addresses {
FIX_IO_APIC_BASE_0,
FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
#endif
#ifdef CONFIG_X86_32
#ifdef CONFIG_KMAP_LOCAL
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
#ifdef CONFIG_PCI_MMCONFIG
FIX_PCIE_MCFG,
#endif
@ -151,7 +157,6 @@ extern void reserve_top_address(unsigned long reserve);
extern int fixmaps_set;
extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);

13
arch/x86/include/asm/highmem.h
View File

@ -23,7 +23,6 @@
#include <linux/interrupt.h>
#include <linux/threads.h>
#include <asm/kmap_types.h>
#include <asm/tlbflush.h>
#include <asm/paravirt.h>
#include <asm/fixmap.h>
@ -58,11 +57,17 @@ extern unsigned long highstart_pfn, highend_pfn;
#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
void *kmap_atomic_pfn(unsigned long pfn);
void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
#define flush_cache_kmaps() do { } while (0)
#define arch_kmap_local_post_map(vaddr, pteval) \
arch_flush_lazy_mmu_mode()
#define arch_kmap_local_post_unmap(vaddr) \
do { \
flush_tlb_one_kernel((vaddr)); \
arch_flush_lazy_mmu_mode(); \
} while (0)
extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn,
unsigned long end_pfn);

13
arch/x86/include/asm/iomap.h
View File

@ -9,19 +9,14 @@
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <linux/highmem.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
void __iomem *
iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
void __iomem *__iomap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
void
iounmap_atomic(void __iomem *kvaddr);
int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);
int
iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);
void
iomap_free(resource_size_t base, unsigned long size);
void iomap_free(resource_size_t base, unsigned long size);
#endif /* _ASM_X86_IOMAP_H */

13
arch/x86/include/asm/kmap_types.h
View File

@ -1,13 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_KMAP_TYPES_H
#define _ASM_X86_KMAP_TYPES_H
#if defined(CONFIG_X86_32) && defined(CONFIG_DEBUG_HIGHMEM)
#define __WITH_KM_FENCE
#endif
#include <asm-generic/kmap_types.h>
#undef __WITH_KM_FENCE
#endif /* _ASM_X86_KMAP_TYPES_H */

1
arch/x86/include/asm/paravirt_types.h
View File

@ -41,7 +41,6 @@
#ifndef __ASSEMBLY__
#include <asm/desc_defs.h>
#include <asm/kmap_types.h>
#include <asm/pgtable_types.h>
#include <asm/nospec-branch.h>

6
arch/x86/include/asm/pgtable_64_types.h
View File

@ -143,7 +143,11 @@ extern unsigned int ptrs_per_p4d;
#define MODULES_VADDR (__START_KERNEL_map + KERNEL_IMAGE_SIZE)
/* The module sections ends with the start of the fixmap */
#define MODULES_END _AC(0xffffffffff000000, UL)
#ifndef CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
# define MODULES_END _AC(0xffffffffff000000, UL)
#else
# define MODULES_END _AC(0xfffffffffe000000, UL)
#endif
#define MODULES_LEN (MODULES_END - MODULES_VADDR)
#define ESPFIX_PGD_ENTRY _AC(-2, UL)

48
arch/x86/kernel/crash_dump_32.c
View File

@ -13,8 +13,6 @@
#include <linux/uaccess.h>
static void *kdump_buf_page;
static inline bool is_crashed_pfn_valid(unsigned long pfn)
{
#ifndef CONFIG_X86_PAE
@ -41,15 +39,11 @@ static inline bool is_crashed_pfn_valid(unsigned long pfn)
* @userbuf: if set, @buf is in user address space, use copy_to_user(),
* otherwise @buf is in kernel address space, use memcpy().
*
* Copy a page from "oldmem". For this page, there is no pte mapped
* in the current kernel. We stitch up a pte, similar to kmap_atomic.
*
* Calling copy_to_user() in atomic context is not desirable. Hence first
* copying the data to a pre-allocated kernel page and then copying to user
* space in non-atomic context.
* Copy a page from "oldmem". For this page, there might be no pte mapped
* in the current kernel.
*/
ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
size_t csize, unsigned long offset, int userbuf)
ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
unsigned long offset, int userbuf)
{
void *vaddr;
@ -59,38 +53,16 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
if (!is_crashed_pfn_valid(pfn))
return -EFAULT;
vaddr = kmap_atomic_pfn(pfn);
vaddr = kmap_local_pfn(pfn);
if (!userbuf) {
memcpy(buf, (vaddr + offset), csize);
kunmap_atomic(vaddr);
memcpy(buf, vaddr + offset, csize);
} else {
if (!kdump_buf_page) {
printk(KERN_WARNING "Kdump: Kdump buffer page not"
" allocated\n");
kunmap_atomic(vaddr);
return -EFAULT;
}
copy_page(kdump_buf_page, vaddr);
kunmap_atomic(vaddr);
if (copy_to_user(buf, (kdump_buf_page + offset), csize))
return -EFAULT;
if (copy_to_user(buf, vaddr + offset, csize))
csize = -EFAULT;
}
kunmap_local(vaddr);
return csize;
}
static int __init kdump_buf_page_init(void)
{
int ret = 0;
kdump_buf_page = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!kdump_buf_page) {
printk(KERN_WARNING "Kdump: Failed to allocate kdump buffer"
" page\n");
ret = -ENOMEM;
}
return ret;
}
arch_initcall(kdump_buf_page_init);

59
arch/x86/mm/highmem_32.c
View File

@ -4,65 +4,6 @@
#include <linux/swap.h> /* for totalram_pages */
#include <linux/memblock.h>
void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
{
unsigned long vaddr;
int idx, type;
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
BUG_ON(!pte_none(*(kmap_pte-idx)));
set_pte(kmap_pte-idx, mk_pte(page, prot));
arch_flush_lazy_mmu_mode();
return (void *)vaddr;
}
EXPORT_SYMBOL(kmap_atomic_high_prot);
/*
* This is the same as kmap_atomic() but can map memory that doesn't
* have a struct page associated with it.
*/
void *kmap_atomic_pfn(unsigned long pfn)
{
return kmap_atomic_prot_pfn(pfn, kmap_prot);
}
EXPORT_SYMBOL_GPL(kmap_atomic_pfn);
void kunmap_atomic_high(void *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
int idx, type;
type = kmap_atomic_idx();
idx = type + KM_TYPE_NR * smp_processor_id();
#ifdef CONFIG_DEBUG_HIGHMEM
WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
#endif
/*
* Force other mappings to Oops if they'll try to access this
* pte without first remap it. Keeping stale mappings around
* is a bad idea also, in case the page changes cacheability
* attributes or becomes a protected page in a hypervisor.
*/
kpte_clear_flush(kmap_pte-idx, vaddr);
kmap_atomic_idx_pop();
arch_flush_lazy_mmu_mode();
}
#ifdef CONFIG_DEBUG_HIGHMEM
else {
BUG_ON(vaddr < PAGE_OFFSET);
BUG_ON(vaddr >= (unsigned long)high_memory);
}
#endif
}
EXPORT_SYMBOL(kunmap_atomic_high);
void __init set_highmem_pages_init(void)
{
struct zone *zone;

15
arch/x86/mm/init_32.c
View File

@ -394,19 +394,6 @@ repeat:
return last_map_addr;
}
pte_t *kmap_pte;
static void __init kmap_init(void)
{
unsigned long kmap_vstart;
/*
* Cache the first kmap pte:
*/
kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
kmap_pte = virt_to_kpte(kmap_vstart);
}
#ifdef CONFIG_HIGHMEM
static void __init permanent_kmaps_init(pgd_t *pgd_base)
{
@ -712,8 +699,6 @@ void __init paging_init(void)
__flush_tlb_all();
kmap_init();
/*
* NOTE: at this point the bootmem allocator is fully available.
*/

57
arch/x86/mm/iomap_32.c
View File

@ -44,28 +44,7 @@ void iomap_free(resource_size_t base, unsigned long size)
}
EXPORT_SYMBOL_GPL(iomap_free);
void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
{
unsigned long vaddr;
int idx, type;
preempt_disable();
pagefault_disable();
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
arch_flush_lazy_mmu_mode();
return (void *)vaddr;
}
/*
* Map 'pfn' using protections 'prot'
*/
void __iomem *
iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
void __iomem *__iomap_local_pfn_prot(unsigned long pfn, pgprot_t prot)
{
/*
* For non-PAT systems, translate non-WB request to UC- just in
@ -81,36 +60,6 @@ iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
/* Filter out unsupported __PAGE_KERNEL* bits: */
pgprot_val(prot) &= __default_kernel_pte_mask;
return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot);
return (void __force __iomem *)__kmap_local_pfn_prot(pfn, prot);
}
EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
void
iounmap_atomic(void __iomem *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
int idx, type;
type = kmap_atomic_idx();
idx = type + KM_TYPE_NR * smp_processor_id();
#ifdef CONFIG_DEBUG_HIGHMEM
WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
#endif
/*
* Force other mappings to Oops if they'll try to access this
* pte without first remap it. Keeping stale mappings around
* is a bad idea also, in case the page changes cacheability
* attributes or becomes a protected page in a hypervisor.
*/
kpte_clear_flush(kmap_pte-idx, vaddr);
kmap_atomic_idx_pop();
}
pagefault_enable();
preempt_enable();
}
EXPORT_SYMBOL_GPL(iounmap_atomic);
EXPORT_SYMBOL_GPL(__iomap_local_pfn_prot);

1
arch/xtensa/Kconfig
View File

@ -666,6 +666,7 @@ endchoice
config HIGHMEM
bool "High Memory Support"
depends on MMU
select KMAP_LOCAL
help
Linux can use the full amount of RAM in the system by
default. However, the default MMUv2 setup only maps the

59
arch/xtensa/include/asm/fixmap.h
View File

@ -16,64 +16,23 @@
#ifdef CONFIG_HIGHMEM
#include <linux/threads.h>
#include <linux/pgtable.h>
#include <asm/kmap_types.h>
#endif
#include <asm/kmap_size.h>
/*
* Here we define all the compile-time 'special' virtual
* addresses. The point is to have a constant address at
* compile time, but to set the physical address only
* in the boot process. We allocate these special addresses
* from the start of the consistent memory region upwards.
* Also this lets us do fail-safe vmalloc(), we
* can guarantee that these special addresses and
* vmalloc()-ed addresses never overlap.
*
* these 'compile-time allocated' memory buffers are
* fixed-size 4k pages. (or larger if used with an increment
* higher than 1) use fixmap_set(idx,phys) to associate
* physical memory with fixmap indices.
*/
/* The map slots for temporary mappings via kmap_atomic/local(). */
enum fixed_addresses {
#ifdef CONFIG_HIGHMEM
/* reserved pte's for temporary kernel mappings */
FIX_KMAP_BEGIN,
FIX_KMAP_END = FIX_KMAP_BEGIN +
(KM_TYPE_NR * NR_CPUS * DCACHE_N_COLORS) - 1,
#endif
(KM_MAX_IDX * NR_CPUS * DCACHE_N_COLORS) - 1,
__end_of_fixed_addresses
};
#define FIXADDR_TOP (XCHAL_KSEG_CACHED_VADDR - PAGE_SIZE)
#define FIXADDR_END (XCHAL_KSEG_CACHED_VADDR - PAGE_SIZE)
#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START ((FIXADDR_TOP - FIXADDR_SIZE) & PMD_MASK)
/* Enforce that FIXADDR_START is PMD aligned to handle cache aliasing */
#define FIXADDR_START ((FIXADDR_END - FIXADDR_SIZE) & PMD_MASK)
#define FIXADDR_TOP (FIXADDR_START + FIXADDR_SIZE - PAGE_SIZE)
#define __fix_to_virt(x) (FIXADDR_START + ((x) << PAGE_SHIFT))
#define __virt_to_fix(x) (((x) - FIXADDR_START) >> PAGE_SHIFT)
#ifndef __ASSEMBLY__
/*
* 'index to address' translation. If anyone tries to use the idx
* directly without translation, we catch the bug with a NULL-deference
* kernel oops. Illegal ranges of incoming indices are caught too.
*/
static __always_inline unsigned long fix_to_virt(const unsigned int idx)
{
/* Check if this memory layout is broken because fixmap overlaps page
* table.
*/
BUILD_BUG_ON(FIXADDR_START <
TLBTEMP_BASE_1 + TLBTEMP_SIZE);
BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
return __fix_to_virt(idx);
}
static inline unsigned long virt_to_fix(const unsigned long vaddr)
{
BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
return __virt_to_fix(vaddr);
}
#endif
#include <asm-generic/fixmap.h>
#endif /* CONFIG_HIGHMEM */
#endif

15
arch/xtensa/include/asm/highmem.h
View File

@ -12,13 +12,13 @@
#ifndef _XTENSA_HIGHMEM_H
#define _XTENSA_HIGHMEM_H
#ifdef CONFIG_HIGHMEM
#include <linux/wait.h>
#include <linux/pgtable.h>
#include <asm/cacheflush.h>
#include <asm/fixmap.h>
#include <asm/kmap_types.h>
#define PKMAP_BASE ((FIXADDR_START - \
#define PKMAP_BASE ((FIXADDR_START - \
(LAST_PKMAP + 1) * PAGE_SIZE) & PMD_MASK)
#define LAST_PKMAP (PTRS_PER_PTE * DCACHE_N_COLORS)
#define LAST_PKMAP_MASK (LAST_PKMAP - 1)
@ -59,6 +59,13 @@ static inline wait_queue_head_t *get_pkmap_wait_queue_head(unsigned int color)
{
return pkmap_map_wait_arr + color;
}
enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn);
#define arch_kmap_local_map_idx kmap_local_map_idx
enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr);
#define arch_kmap_local_unmap_idx kmap_local_unmap_idx
#endif
extern pte_t *pkmap_page_table;
@ -68,6 +75,10 @@ static inline void flush_cache_kmaps(void)
flush_cache_all();
}
#define arch_kmap_local_post_unmap(vaddr) \
local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE)
void kmap_init(void);
#endif /* CONFIG_HIGHMEM */
#endif

66
arch/xtensa/mm/highmem.c
View File

@ -12,8 +12,6 @@
#include <linux/highmem.h>
#include <asm/tlbflush.h>
static pte_t *kmap_pte;
#if DCACHE_WAY_SIZE > PAGE_SIZE
unsigned int last_pkmap_nr_arr[DCACHE_N_COLORS];
wait_queue_head_t pkmap_map_wait_arr[DCACHE_N_COLORS];
@ -25,67 +23,37 @@ static void __init kmap_waitqueues_init(void)
for (i = 0; i < ARRAY_SIZE(pkmap_map_wait_arr); ++i)
init_waitqueue_head(pkmap_map_wait_arr + i);
}
#else
static inline void kmap_waitqueues_init(void)
{
}
#endif
static inline enum fixed_addresses kmap_idx(int type, unsigned long color)
{
return (type + KM_TYPE_NR * smp_processor_id()) * DCACHE_N_COLORS +
color;
int idx = (type + KM_MAX_IDX * smp_processor_id()) * DCACHE_N_COLORS;
/*
* The fixmap operates top down, so the color offset needs to be
* reverse as well.
*/
return idx + DCACHE_N_COLORS - 1 - color;
}
void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn)
{
enum fixed_addresses idx;
unsigned long vaddr;
return kmap_idx(type, DCACHE_ALIAS(pfn << PAGE_SHIFT));
}
idx = kmap_idx(kmap_atomic_idx_push(),
DCACHE_ALIAS(page_to_phys(page)));
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(*(kmap_pte + idx)));
enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr)
{
return kmap_idx(type, DCACHE_ALIAS(addr));
}
#else
static inline void kmap_waitqueues_init(void) { }
#endif
set_pte(kmap_pte + idx, mk_pte(page, prot));
return (void *)vaddr;
}
EXPORT_SYMBOL(kmap_atomic_high_prot);
void kunmap_atomic_high(void *kvaddr)
{
if (kvaddr >= (void *)FIXADDR_START &&
kvaddr < (void *)FIXADDR_TOP) {
int idx = kmap_idx(kmap_atomic_idx(),
DCACHE_ALIAS((unsigned long)kvaddr));
/*
* Force other mappings to Oops if they'll try to access this
* pte without first remap it. Keeping stale mappings around
* is a bad idea also, in case the page changes cacheability
* attributes or becomes a protected page in a hypervisor.
*/
pte_clear(&init_mm, kvaddr, kmap_pte + idx);
local_flush_tlb_kernel_range((unsigned long)kvaddr,
(unsigned long)kvaddr + PAGE_SIZE);
kmap_atomic_idx_pop();
}
}
EXPORT_SYMBOL(kunmap_atomic_high);
void __init kmap_init(void)
{
unsigned long kmap_vstart;
/* Check if this memory layout is broken because PKMAP overlaps
* page table.
*/
BUILD_BUG_ON(PKMAP_BASE < TLBTEMP_BASE_1 + TLBTEMP_SIZE);
/* cache the first kmap pte */
kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
kmap_pte = virt_to_kpte(kmap_vstart);
kmap_waitqueues_init();
}

4
arch/xtensa/mm/init.c
View File

@ -147,8 +147,8 @@ void __init mem_init(void)
#ifdef CONFIG_HIGHMEM
PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
(LAST_PKMAP*PAGE_SIZE) >> 10,
FIXADDR_START, FIXADDR_TOP,
(FIXADDR_TOP - FIXADDR_START) >> 10,
FIXADDR_START, FIXADDR_END,
(FIXADDR_END - FIXADDR_START) >> 10,
#endif
PAGE_OFFSET, PAGE_OFFSET +
(max_low_pfn - min_low_pfn) * PAGE_SIZE,

3
arch/xtensa/mm/mmu.c
View File

@ -52,7 +52,8 @@ static void * __init init_pmd(unsigned long vaddr, unsigned long n_pages)
static void __init fixedrange_init(void)
{
init_pmd(__fix_to_virt(0), __end_of_fixed_addresses);
BUILD_BUG_ON(FIXADDR_START < TLBTEMP_BASE_1 + TLBTEMP_SIZE);
init_pmd(FIXADDR_START, __end_of_fixed_addresses);
}
#endif

1
fs/aio.c
View File

@ -43,7 +43,6 @@
#include <linux/mount.h>
#include <linux/pseudo_fs.h>
#include <asm/kmap_types.h>
#include <linux/uaccess.h>
#include <linux/nospec.h>

1
fs/btrfs/ctree.h
View File

@ -17,7 +17,6 @@
#include <linux/wait.h>
#include <linux/slab.h>
#include <trace/events/btrfs.h>
#include <asm/kmap_types.h>
#include <asm/unaligned.h>
#include <linux/pagemap.h>
#include <linux/btrfs.h>

2
include/asm-generic/Kbuild
View File

@ -30,7 +30,7 @@ mandatory-y += irq.h
mandatory-y += irq_regs.h
mandatory-y += irq_work.h
mandatory-y += kdebug.h
mandatory-y += kmap_types.h
mandatory-y += kmap_size.h
mandatory-y += kprobes.h
mandatory-y += linkage.h
mandatory-y += local.h

12
include/asm-generic/kmap_size.h Normal file
View File

@ -0,0 +1,12 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_GENERIC_KMAP_SIZE_H
#define _ASM_GENERIC_KMAP_SIZE_H
/* For debug this provides guard pages between the maps */
#ifdef CONFIG_DEBUG_KMAP_LOCAL
# define KM_MAX_IDX 33
#else
# define KM_MAX_IDX 16
#endif
#endif

11
include/asm-generic/kmap_types.h
View File

@ -1,11 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_GENERIC_KMAP_TYPES_H
#define _ASM_GENERIC_KMAP_TYPES_H
#ifdef __WITH_KM_FENCE
# define KM_TYPE_NR 41
#else
# define KM_TYPE_NR 20
#endif
#endif

232
include/linux/highmem-internal.h Normal file
View File

@ -0,0 +1,232 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_HIGHMEM_INTERNAL_H
#define _LINUX_HIGHMEM_INTERNAL_H
/*
* Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft.
*/
#ifdef CONFIG_KMAP_LOCAL
void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
void kunmap_local_indexed(void *vaddr);
void kmap_local_fork(struct task_struct *tsk);
void __kmap_local_sched_out(void);
void __kmap_local_sched_in(void);
static inline void kmap_assert_nomap(void)
{
DEBUG_LOCKS_WARN_ON(current->kmap_ctrl.idx);
}
#else
static inline void kmap_local_fork(struct task_struct *tsk) { }
static inline void kmap_assert_nomap(void) { }
#endif
#ifdef CONFIG_HIGHMEM
#include <asm/highmem.h>
#ifndef ARCH_HAS_KMAP_FLUSH_TLB
static inline void kmap_flush_tlb(unsigned long addr) { }
#endif
#ifndef kmap_prot
#define kmap_prot PAGE_KERNEL
#endif
void *kmap_high(struct page *page);
void kunmap_high(struct page *page);
void __kmap_flush_unused(void);
struct page *__kmap_to_page(void *addr);
static inline void *kmap(struct page *page)
{
void *addr;
might_sleep();
if (!PageHighMem(page))
addr = page_address(page);
else
addr = kmap_high(page);
kmap_flush_tlb((unsigned long)addr);
return addr;
}
static inline void kunmap(struct page *page)
{
might_sleep();
if (!PageHighMem(page))
return;
kunmap_high(page);
}
static inline struct page *kmap_to_page(void *addr)
{
return __kmap_to_page(addr);
}
static inline void kmap_flush_unused(void)
{
__kmap_flush_unused();
}
static inline void *kmap_local_page(struct page *page)
{
return __kmap_local_page_prot(page, kmap_prot);
}
static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
{
return __kmap_local_page_prot(page, prot);
}
static inline void *kmap_local_pfn(unsigned long pfn)
{
return __kmap_local_pfn_prot(pfn, kmap_prot);
}
static inline void __kunmap_local(void *vaddr)
{
kunmap_local_indexed(vaddr);
}
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
preempt_disable();
pagefault_disable();
return __kmap_local_page_prot(page, prot);
}
static inline void *kmap_atomic(struct page *page)
{
return kmap_atomic_prot(page, kmap_prot);
}
static inline void *kmap_atomic_pfn(unsigned long pfn)
{
preempt_disable();
pagefault_disable();
return __kmap_local_pfn_prot(pfn, kmap_prot);
}
static inline void __kunmap_atomic(void *addr)
{
kunmap_local_indexed(addr);
pagefault_enable();
preempt_enable();
}
unsigned int __nr_free_highpages(void);
extern atomic_long_t _totalhigh_pages;
static inline unsigned int nr_free_highpages(void)
{
return __nr_free_highpages();
}
static inline unsigned long totalhigh_pages(void)
{
return (unsigned long)atomic_long_read(&_totalhigh_pages);
}
static inline void totalhigh_pages_inc(void)
{
atomic_long_inc(&_totalhigh_pages);
}
static inline void totalhigh_pages_add(long count)
{
atomic_long_add(count, &_totalhigh_pages);
}
#else /* CONFIG_HIGHMEM */
static inline struct page *kmap_to_page(void *addr)
{
return virt_to_page(addr);
}
static inline void *kmap(struct page *page)
{
might_sleep();
return page_address(page);
}
static inline void kunmap_high(struct page *page) { }
static inline void kmap_flush_unused(void) { }
static inline void kunmap(struct page *page)
{
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
kunmap_flush_on_unmap(page_address(page));
#endif
}
static inline void *kmap_local_page(struct page *page)
{
return page_address(page);
}
static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
{
return kmap_local_page(page);
}
static inline void *kmap_local_pfn(unsigned long pfn)
{
return kmap_local_page(pfn_to_page(pfn));
}
static inline void __kunmap_local(void *addr)
{
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
kunmap_flush_on_unmap(addr);
#endif
}
static inline void *kmap_atomic(struct page *page)
{
preempt_disable();
pagefault_disable();
return page_address(page);
}
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
return kmap_atomic(page);
}
static inline void *kmap_atomic_pfn(unsigned long pfn)
{
return kmap_atomic(pfn_to_page(pfn));
}
static inline void __kunmap_atomic(void *addr)
{
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
kunmap_flush_on_unmap(addr);
#endif
pagefault_enable();
preempt_enable();
}
static inline unsigned int nr_free_highpages(void) { return 0; }
static inline unsigned long totalhigh_pages(void) { return 0UL; }
#endif /* CONFIG_HIGHMEM */
/*
* Prevent people trying to call kunmap_atomic() as if it were kunmap()
* kunmap_atomic() should get the return value of kmap_atomic, not the page.
*/
#define kunmap_atomic(__addr) \
do { \
BUILD_BUG_ON(__same_type((__addr), struct page *)); \
__kunmap_atomic(__addr); \
} while (0)
#define kunmap_local(__addr) \
do { \
BUILD_BUG_ON(__same_type((__addr), struct page *)); \
__kunmap_local(__addr); \
} while (0)
#endif

306
include/linux/highmem.h
View File

@ -11,6 +11,119 @@
#include <asm/cacheflush.h>
#include "highmem-internal.h"
/**
* kmap - Map a page for long term usage
* @page: Pointer to the page to be mapped
*
* Returns: The virtual address of the mapping
*
* Can only be invoked from preemptible task context because on 32bit
* systems with CONFIG_HIGHMEM enabled this function might sleep.
*
* For systems with CONFIG_HIGHMEM=n and for pages in the low memory area
* this returns the virtual address of the direct kernel mapping.
*
* The returned virtual address is globally visible and valid up to the
* point where it is unmapped via kunmap(). The pointer can be handed to
* other contexts.
*
* For highmem pages on 32bit systems this can be slow as the mapping space
* is limited and protected by a global lock. In case that there is no
* mapping slot available the function blocks until a slot is released via
* kunmap().
*/
static inline void *kmap(struct page *page);
/**
* kunmap - Unmap the virtual address mapped by kmap()
* @addr: Virtual address to be unmapped
*
* Counterpart to kmap(). A NOOP for CONFIG_HIGHMEM=n and for mappings of
* pages in the low memory area.
*/
static inline void kunmap(struct page *page);
/**
* kmap_to_page - Get the page for a kmap'ed address
* @addr: The address to look up
*
* Returns: The page which is mapped to @addr.
*/
static inline struct page *kmap_to_page(void *addr);
/**
* kmap_flush_unused - Flush all unused kmap mappings in order to
* remove stray mappings
*/
static inline void kmap_flush_unused(void);
/**
* kmap_local_page - Map a page for temporary usage
* @page: Pointer to the page to be mapped
*
* Returns: The virtual address of the mapping
*
* Can be invoked from any context.
*
* Requires careful handling when nesting multiple mappings because the map
* management is stack based. The unmap has to be in the reverse order of
* the map operation:
*
* addr1 = kmap_local_page(page1);
* addr2 = kmap_local_page(page2);
* ...
* kunmap_local(addr2);
* kunmap_local(addr1);
*
* Unmapping addr1 before addr2 is invalid and causes malfunction.
*
* Contrary to kmap() mappings the mapping is only valid in the context of
* the caller and cannot be handed to other contexts.
*
* On CONFIG_HIGHMEM=n kernels and for low memory pages this returns the
* virtual address of the direct mapping. Only real highmem pages are
* temporarily mapped.
*
* While it is significantly faster than kmap() for the higmem case it
* comes with restrictions about the pointer validity. Only use when really
* necessary.
*
* On HIGHMEM enabled systems mapping a highmem page has the side effect of
* disabling migration in order to keep the virtual address stable across
* preemption. No caller of kmap_local_page() can rely on this side effect.
*/
static inline void *kmap_local_page(struct page *page);
/**
* kmap_atomic - Atomically map a page for temporary usage - Deprecated!
* @page: Pointer to the page to be mapped
*
* Returns: The virtual address of the mapping
*
* Effectively a wrapper around kmap_local_page() which disables pagefaults
* and preemption.
*
* Do not use in new code. Use kmap_local_page() instead.
*/
static inline void *kmap_atomic(struct page *page);
/**
* kunmap_atomic - Unmap the virtual address mapped by kmap_atomic()
* @addr: Virtual address to be unmapped
*
* Counterpart to kmap_atomic().
*
* Effectively a wrapper around kunmap_local() which additionally undoes
* the side effects of kmap_atomic(), i.e. reenabling pagefaults and
* preemption.
*/
/* Highmem related interfaces for management code */
static inline unsigned int nr_free_highpages(void);
static inline unsigned long totalhigh_pages(void);
#ifndef ARCH_HAS_FLUSH_ANON_PAGE
static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
{
@ -29,199 +142,6 @@ static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
}
#endif
#include <asm/kmap_types.h>
#ifdef CONFIG_HIGHMEM
extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
extern void kunmap_atomic_high(void *kvaddr);
#include <asm/highmem.h>
#ifndef ARCH_HAS_KMAP_FLUSH_TLB
static inline void kmap_flush_tlb(unsigned long addr) { }
#endif
#ifndef kmap_prot
#define kmap_prot PAGE_KERNEL
#endif
void *kmap_high(struct page *page);
static inline void *kmap(struct page *page)
{
void *addr;
might_sleep();
if (!PageHighMem(page))
addr = page_address(page);
else
addr = kmap_high(page);
kmap_flush_tlb((unsigned long)addr);
return addr;
}
void kunmap_high(struct page *page);
static inline void kunmap(struct page *page)
{
might_sleep();
if (!PageHighMem(page))
return;
kunmap_high(page);
}
/*
* kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
* no global lock is needed and because the kmap code must perform a global TLB
* invalidation when the kmap pool wraps.
*
* However when holding an atomic kmap it is not legal to sleep, so atomic
* kmaps are appropriate for short, tight code paths only.
*
* The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
* gives a more generic (and caching) interface. But kmap_atomic can
* be used in IRQ contexts, so in some (very limited) cases we need
* it.
*/
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
return kmap_atomic_high_prot(page, prot);
}
#define kmap_atomic(page) kmap_atomic_prot(page, kmap_prot)
/* declarations for linux/mm/highmem.c */
unsigned int nr_free_highpages(void);
extern atomic_long_t _totalhigh_pages;
static inline unsigned long totalhigh_pages(void)
{
return (unsigned long)atomic_long_read(&_totalhigh_pages);
}
static inline void totalhigh_pages_inc(void)
{
atomic_long_inc(&_totalhigh_pages);
}
static inline void totalhigh_pages_dec(void)
{
atomic_long_dec(&_totalhigh_pages);
}
static inline void totalhigh_pages_add(long count)
{
atomic_long_add(count, &_totalhigh_pages);
}
static inline void totalhigh_pages_set(long val)
{
atomic_long_set(&_totalhigh_pages, val);
}
void kmap_flush_unused(void);
struct page *kmap_to_page(void *addr);
#else /* CONFIG_HIGHMEM */
static inline unsigned int nr_free_highpages(void) { return 0; }
static inline struct page *kmap_to_page(void *addr)
{
return virt_to_page(addr);
}
static inline unsigned long totalhigh_pages(void) { return 0UL; }
static inline void *kmap(struct page *page)
{
might_sleep();
return page_address(page);
}
static inline void kunmap_high(struct page *page)
{
}
static inline void kunmap(struct page *page)
{
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
kunmap_flush_on_unmap(page_address(page));
#endif
}
static inline void *kmap_atomic(struct page *page)
{
preempt_disable();
pagefault_disable();
return page_address(page);
}
#define kmap_atomic_prot(page, prot) kmap_atomic(page)
static inline void kunmap_atomic_high(void *addr)
{
/*
* Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
* handles re-enabling faults + preemption
*/
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
kunmap_flush_on_unmap(addr);
#endif
}
#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
#define kmap_flush_unused() do {} while(0)
#endif /* CONFIG_HIGHMEM */
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
DECLARE_PER_CPU(int, __kmap_atomic_idx);
static inline int kmap_atomic_idx_push(void)
{
int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
#ifdef CONFIG_DEBUG_HIGHMEM
WARN_ON_ONCE(in_irq() && !irqs_disabled());
BUG_ON(idx >= KM_TYPE_NR);
#endif
return idx;
}
static inline int kmap_atomic_idx(void)
{
return __this_cpu_read(__kmap_atomic_idx) - 1;
}
static inline void kmap_atomic_idx_pop(void)
{
#ifdef CONFIG_DEBUG_HIGHMEM
int idx = __this_cpu_dec_return(__kmap_atomic_idx);
BUG_ON(idx < 0);
#else
__this_cpu_dec(__kmap_atomic_idx);
#endif
}
#endif
/*
* Prevent people trying to call kunmap_atomic() as if it were kunmap()
* kunmap_atomic() should get the return value of kmap_atomic, not the page.
*/
#define kunmap_atomic(addr) \
do { \
BUILD_BUG_ON(__same_type((addr), struct page *)); \
kunmap_atomic_high(addr); \
pagefault_enable(); \
preempt_enable(); \
} while (0)
/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
#ifndef clear_user_highpage
static inline void clear_user_highpage(struct page *page, unsigned long vaddr)

38
include/linux/io-mapping.h
View File

@ -69,13 +69,32 @@ io_mapping_map_atomic_wc(struct io_mapping *mapping,
BUG_ON(offset >= mapping->size);
phys_addr = mapping->base + offset;
return iomap_atomic_prot_pfn(PHYS_PFN(phys_addr), mapping->prot);
preempt_disable();
pagefault_disable();
return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot);
}
static inline void
io_mapping_unmap_atomic(void __iomem *vaddr)
{
iounmap_atomic(vaddr);
kunmap_local_indexed((void __force *)vaddr);
pagefault_enable();
preempt_enable();
}
static inline void __iomem *
io_mapping_map_local_wc(struct io_mapping *mapping, unsigned long offset)
{
resource_size_t phys_addr;
BUG_ON(offset >= mapping->size);
phys_addr = mapping->base + offset;
return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot);
}
static inline void io_mapping_unmap_local(void __iomem *vaddr)
{
kunmap_local_indexed((void __force *)vaddr);
}
static inline void __iomem *
@ -97,7 +116,7 @@ io_mapping_unmap(void __iomem *vaddr)
iounmap(vaddr);
}
#else
#else /* HAVE_ATOMIC_IOMAP */
#include <linux/uaccess.h>
@ -162,7 +181,18 @@ io_mapping_unmap_atomic(void __iomem *vaddr)
preempt_enable();
}
#endif /* HAVE_ATOMIC_IOMAP */
static inline void __iomem *
io_mapping_map_local_wc(struct io_mapping *mapping, unsigned long offset)
{
return io_mapping_map_wc(mapping, offset, PAGE_SIZE);
}
static inline void io_mapping_unmap_local(void __iomem *vaddr)
{
io_mapping_unmap(vaddr);
}
#endif /* !HAVE_ATOMIC_IOMAP */
static inline struct io_mapping *
io_mapping_create_wc(resource_size_t base,

9
include/linux/sched.h
View File

@ -35,6 +35,7 @@
#include <linux/rseq.h>
#include <linux/seqlock.h>
#include <linux/kcsan.h>
#include <asm/kmap_size.h>
/* task_struct member predeclarations (sorted alphabetically): */
struct audit_context;
@ -638,6 +639,13 @@ struct wake_q_node {
struct wake_q_node *next;
};
struct kmap_ctrl {
#ifdef CONFIG_KMAP_LOCAL
int idx;
pte_t pteval[KM_MAX_IDX];
#endif
};
struct task_struct {
#ifdef CONFIG_THREAD_INFO_IN_TASK
/*
@ -1318,6 +1326,7 @@ struct task_struct {
unsigned int sequential_io;
unsigned int sequential_io_avg;
#endif
struct kmap_ctrl kmap_ctrl;
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
unsigned long task_state_change;
#endif

2
kernel/entry/common.c
View File

@ -2,6 +2,7 @@
#include <linux/context_tracking.h>
#include <linux/entry-common.h>
#include <linux/highmem.h>
#include <linux/livepatch.h>
#include <linux/audit.h>
@ -203,6 +204,7 @@ static void exit_to_user_mode_prepare(struct pt_regs *regs)
/* Ensure that the address limit is intact and no locks are held */
addr_limit_user_check();
kmap_assert_nomap();
lockdep_assert_irqs_disabled();
lockdep_sys_exit();
}

1
kernel/fork.c
View File

@ -931,6 +931,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
account_kernel_stack(tsk, 1);
kcov_task_init(tsk);
kmap_local_fork(tsk);
#ifdef CONFIG_FAULT_INJECTION
tsk->fail_nth = 0;

25
kernel/sched/core.c
View File

@ -4091,6 +4091,22 @@ static inline void finish_lock_switch(struct rq *rq)
# define finish_arch_post_lock_switch() do { } while (0)
#endif
static inline void kmap_local_sched_out(void)
{
#ifdef CONFIG_KMAP_LOCAL
if (unlikely(current->kmap_ctrl.idx))
__kmap_local_sched_out();
#endif
}
static inline void kmap_local_sched_in(void)
{
#ifdef CONFIG_KMAP_LOCAL
if (unlikely(current->kmap_ctrl.idx))
__kmap_local_sched_in();
#endif
}
/**
* prepare_task_switch - prepare to switch tasks
* @rq: the runqueue preparing to switch
@ -4113,6 +4129,7 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev,
perf_event_task_sched_out(prev, next);
rseq_preempt(prev);
fire_sched_out_preempt_notifiers(prev, next);
kmap_local_sched_out();
prepare_task(next);
prepare_arch_switch(next);
}
@ -4179,6 +4196,14 @@ static struct rq *finish_task_switch(struct task_struct *prev)
finish_lock_switch(rq);
finish_arch_post_lock_switch();
kcov_finish_switch(current);
/*
* kmap_local_sched_out() is invoked with rq::lock held and
* interrupts disabled. There is no requirement for that, but the
* sched out code does not have an interrupt enabled section.
* Restoring the maps on sched in does not require interrupts being
* disabled either.
*/
kmap_local_sched_in();
fire_sched_in_preempt_notifiers(current);
/*

22
lib/Kconfig.debug
View File

@ -849,9 +849,31 @@ config DEBUG_PER_CPU_MAPS
Say N if unsure.
config DEBUG_KMAP_LOCAL
bool "Debug kmap_local temporary mappings"
depends on DEBUG_KERNEL && KMAP_LOCAL
help
This option enables additional error checking for the kmap_local
infrastructure. Disable for production use.
config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
bool
config DEBUG_KMAP_LOCAL_FORCE_MAP
bool "Enforce kmap_local temporary mappings"
depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
select KMAP_LOCAL
select DEBUG_KMAP_LOCAL
help
This option enforces temporary mappings through the kmap_local
mechanism for non-highmem pages and on non-highmem systems.
Disable this for production systems!
config DEBUG_HIGHMEM
bool "Highmem debugging"
depends on DEBUG_KERNEL && HIGHMEM
select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
select DEBUG_KMAP_LOCAL
help
This option enables additional error checking for high memory
systems. Disable for production systems.

3
mm/Kconfig
View File

@ -859,4 +859,7 @@ config ARCH_HAS_HUGEPD
config MAPPING_DIRTY_HELPERS
bool
config KMAP_LOCAL
bool
endmenu

272
mm/highmem.c
View File

@ -31,10 +31,6 @@
#include <asm/tlbflush.h>
#include <linux/vmalloc.h>
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
DEFINE_PER_CPU(int, __kmap_atomic_idx);
#endif
/*
* Virtual_count is not a pure "count".
* 0 means that it is not mapped, and has not been mapped
@ -108,9 +104,7 @@ static inline wait_queue_head_t *get_pkmap_wait_queue_head(unsigned int color)
atomic_long_t _totalhigh_pages __read_mostly;
EXPORT_SYMBOL(_totalhigh_pages);
EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
unsigned int nr_free_highpages (void)
unsigned int __nr_free_highpages (void)
{
struct zone *zone;
unsigned int pages = 0;
@ -147,7 +141,7 @@ pte_t * pkmap_page_table;
do { spin_unlock(&kmap_lock); (void)(flags); } while (0)
#endif
struct page *kmap_to_page(void *vaddr)
struct page *__kmap_to_page(void *vaddr)
{
unsigned long addr = (unsigned long)vaddr;
@ -158,7 +152,7 @@ struct page *kmap_to_page(void *vaddr)
return virt_to_page(addr);
}
EXPORT_SYMBOL(kmap_to_page);
EXPORT_SYMBOL(__kmap_to_page);
static void flush_all_zero_pkmaps(void)
{
@ -200,10 +194,7 @@ static void flush_all_zero_pkmaps(void)
flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP));
}
/**
* kmap_flush_unused - flush all unused kmap mappings in order to remove stray mappings
*/
void kmap_flush_unused(void)
void __kmap_flush_unused(void)
{
lock_kmap();
flush_all_zero_pkmaps();
@ -367,9 +358,260 @@ void kunmap_high(struct page *page)
if (need_wakeup)
wake_up(pkmap_map_wait);
}
EXPORT_SYMBOL(kunmap_high);
#endif /* CONFIG_HIGHMEM */
#endif /* CONFIG_HIGHMEM */
#ifdef CONFIG_KMAP_LOCAL
#include <asm/kmap_size.h>
/*
* With DEBUG_KMAP_LOCAL the stack depth is doubled and every second
* slot is unused which acts as a guard page
*/
#ifdef CONFIG_DEBUG_KMAP_LOCAL
# define KM_INCR 2
#else
# define KM_INCR 1
#endif
static inline int kmap_local_idx_push(void)
{
WARN_ON_ONCE(in_irq() && !irqs_disabled());
current->kmap_ctrl.idx += KM_INCR;
BUG_ON(current->kmap_ctrl.idx >= KM_MAX_IDX);
return current->kmap_ctrl.idx - 1;
}
static inline int kmap_local_idx(void)
{
return current->kmap_ctrl.idx - 1;
}
static inline void kmap_local_idx_pop(void)
{
current->kmap_ctrl.idx -= KM_INCR;
BUG_ON(current->kmap_ctrl.idx < 0);
}
#ifndef arch_kmap_local_post_map
# define arch_kmap_local_post_map(vaddr, pteval) do { } while (0)
#endif
#ifndef arch_kmap_local_pre_unmap
# define arch_kmap_local_pre_unmap(vaddr) do { } while (0)
#endif
#ifndef arch_kmap_local_post_unmap
# define arch_kmap_local_post_unmap(vaddr) do { } while (0)
#endif
#ifndef arch_kmap_local_map_idx
#define arch_kmap_local_map_idx(idx, pfn) kmap_local_calc_idx(idx)
#endif
#ifndef arch_kmap_local_unmap_idx
#define arch_kmap_local_unmap_idx(idx, vaddr) kmap_local_calc_idx(idx)
#endif
#ifndef arch_kmap_local_high_get
static inline void *arch_kmap_local_high_get(struct page *page)
{
return NULL;
}
#endif
/* Unmap a local mapping which was obtained by kmap_high_get() */
static inline bool kmap_high_unmap_local(unsigned long vaddr)
{
#ifdef ARCH_NEEDS_KMAP_HIGH_GET
if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
return true;
}
#endif
return false;
}
static inline int kmap_local_calc_idx(int idx)
{
return idx + KM_MAX_IDX * smp_processor_id();
}
static pte_t *__kmap_pte;
static pte_t *kmap_get_pte(void)
{
if (!__kmap_pte)
__kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
return __kmap_pte;
}
void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot)
{
pte_t pteval, *kmap_pte = kmap_get_pte();
unsigned long vaddr;
int idx;
/*
* Disable migration so resulting virtual address is stable
* accross preemption.
*/
migrate_disable();
preempt_disable();
idx = arch_kmap_local_map_idx(kmap_local_idx_push(), pfn);
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
BUG_ON(!pte_none(*(kmap_pte - idx)));
pteval = pfn_pte(pfn, prot);
set_pte_at(&init_mm, vaddr, kmap_pte - idx, pteval);
arch_kmap_local_post_map(vaddr, pteval);
current->kmap_ctrl.pteval[kmap_local_idx()] = pteval;
preempt_enable();
return (void *)vaddr;
}
EXPORT_SYMBOL_GPL(__kmap_local_pfn_prot);
void *__kmap_local_page_prot(struct page *page, pgprot_t prot)
{
void *kmap;
/*
* To broaden the usage of the actual kmap_local() machinery always map
* pages when debugging is enabled and the architecture has no problems
* with alias mappings.
*/
if (!IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) && !PageHighMem(page))
return page_address(page);
/* Try kmap_high_get() if architecture has it enabled */
kmap = arch_kmap_local_high_get(page);
if (kmap)
return kmap;
return __kmap_local_pfn_prot(page_to_pfn(page), prot);
}
EXPORT_SYMBOL(__kmap_local_page_prot);
void kunmap_local_indexed(void *vaddr)
{
unsigned long addr = (unsigned long) vaddr & PAGE_MASK;
pte_t *kmap_pte = kmap_get_pte();
int idx;
if (addr < __fix_to_virt(FIX_KMAP_END) ||
addr > __fix_to_virt(FIX_KMAP_BEGIN)) {
if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP)) {
/* This _should_ never happen! See above. */
WARN_ON_ONCE(1);
return;
}
/*
* Handle mappings which were obtained by kmap_high_get()
* first as the virtual address of such mappings is below
* PAGE_OFFSET. Warn for all other addresses which are in
* the user space part of the virtual address space.
*/
if (!kmap_high_unmap_local(addr))
WARN_ON_ONCE(addr < PAGE_OFFSET);
return;
}
preempt_disable();
idx = arch_kmap_local_unmap_idx(kmap_local_idx(), addr);
WARN_ON_ONCE(addr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
arch_kmap_local_pre_unmap(addr);
pte_clear(&init_mm, addr, kmap_pte - idx);
arch_kmap_local_post_unmap(addr);
current->kmap_ctrl.pteval[kmap_local_idx()] = __pte(0);
kmap_local_idx_pop();
preempt_enable();
migrate_enable();
}
EXPORT_SYMBOL(kunmap_local_indexed);
/*
* Invoked before switch_to(). This is safe even when during or after
* clearing the maps an interrupt which needs a kmap_local happens because
* the task::kmap_ctrl.idx is not modified by the unmapping code so a
* nested kmap_local will use the next unused index and restore the index
* on unmap. The already cleared kmaps of the outgoing task are irrelevant
* because the interrupt context does not know about them. The same applies
* when scheduling back in for an interrupt which happens before the
* restore is complete.
*/
void __kmap_local_sched_out(void)
{
struct task_struct *tsk = current;
pte_t *kmap_pte = kmap_get_pte();
int i;
/* Clear kmaps */
for (i = 0; i < tsk->kmap_ctrl.idx; i++) {
pte_t pteval = tsk->kmap_ctrl.pteval[i];
unsigned long addr;
int idx;
/* With debug all even slots are unmapped and act as guard */
if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !(i & 0x01)) {
WARN_ON_ONCE(!pte_none(pteval));
continue;
}
if (WARN_ON_ONCE(pte_none(pteval)))
continue;
/*
* This is a horrible hack for XTENSA to calculate the
* coloured PTE index. Uses the PFN encoded into the pteval
* and the map index calculation because the actual mapped
* virtual address is not stored in task::kmap_ctrl.
* For any sane architecture this is optimized out.
*/
idx = arch_kmap_local_map_idx(i, pte_pfn(pteval));
addr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
arch_kmap_local_pre_unmap(addr);
pte_clear(&init_mm, addr, kmap_pte - idx);
arch_kmap_local_post_unmap(addr);
}
}
void __kmap_local_sched_in(void)
{
struct task_struct *tsk = current;
pte_t *kmap_pte = kmap_get_pte();
int i;
/* Restore kmaps */
for (i = 0; i < tsk->kmap_ctrl.idx; i++) {
pte_t pteval = tsk->kmap_ctrl.pteval[i];
unsigned long addr;
int idx;
/* With debug all even slots are unmapped and act as guard */
if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !(i & 0x01)) {
WARN_ON_ONCE(!pte_none(pteval));
continue;
}
if (WARN_ON_ONCE(pte_none(pteval)))
continue;
/* See comment in __kmap_local_sched_out() */
idx = arch_kmap_local_map_idx(i, pte_pfn(pteval));
addr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
set_pte_at(&init_mm, addr, kmap_pte - idx, pteval);
arch_kmap_local_post_map(addr, pteval);
}
}
void kmap_local_fork(struct task_struct *tsk)
{
if (WARN_ON_ONCE(tsk->kmap_ctrl.idx))
memset(&tsk->kmap_ctrl, 0, sizeof(tsk->kmap_ctrl));
}
#endif
#if defined(HASHED_PAGE_VIRTUAL)