1736 lines
46 KiB
C
1736 lines
46 KiB
C
/*
|
|
* PowerPC64 port by Mike Corrigan and Dave Engebretsen
|
|
* {mikejc|engebret}@us.ibm.com
|
|
*
|
|
* Copyright (c) 2000 Mike Corrigan <mikejc@us.ibm.com>
|
|
*
|
|
* SMP scalability work:
|
|
* Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
|
|
*
|
|
* Module name: htab.c
|
|
*
|
|
* Description:
|
|
* PowerPC Hashed Page Table functions
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#undef DEBUG
|
|
#undef DEBUG_LOW
|
|
|
|
#include <linux/spinlock.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/sysctl.h>
|
|
#include <linux/export.h>
|
|
#include <linux/ctype.h>
|
|
#include <linux/cache.h>
|
|
#include <linux/init.h>
|
|
#include <linux/signal.h>
|
|
#include <linux/memblock.h>
|
|
#include <linux/context_tracking.h>
|
|
#include <linux/libfdt.h>
|
|
|
|
#include <asm/processor.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/mmu.h>
|
|
#include <asm/mmu_context.h>
|
|
#include <asm/page.h>
|
|
#include <asm/types.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/machdep.h>
|
|
#include <asm/prom.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/io.h>
|
|
#include <asm/eeh.h>
|
|
#include <asm/tlb.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/cputable.h>
|
|
#include <asm/sections.h>
|
|
#include <asm/copro.h>
|
|
#include <asm/udbg.h>
|
|
#include <asm/code-patching.h>
|
|
#include <asm/fadump.h>
|
|
#include <asm/firmware.h>
|
|
#include <asm/tm.h>
|
|
#include <asm/trace.h>
|
|
#include <asm/ps3.h>
|
|
|
|
#ifdef DEBUG
|
|
#define DBG(fmt...) udbg_printf(fmt)
|
|
#else
|
|
#define DBG(fmt...)
|
|
#endif
|
|
|
|
#ifdef DEBUG_LOW
|
|
#define DBG_LOW(fmt...) udbg_printf(fmt)
|
|
#else
|
|
#define DBG_LOW(fmt...)
|
|
#endif
|
|
|
|
#define KB (1024)
|
|
#define MB (1024*KB)
|
|
#define GB (1024L*MB)
|
|
|
|
/*
|
|
* Note: pte --> Linux PTE
|
|
* HPTE --> PowerPC Hashed Page Table Entry
|
|
*
|
|
* Execution context:
|
|
* htab_initialize is called with the MMU off (of course), but
|
|
* the kernel has been copied down to zero so it can directly
|
|
* reference global data. At this point it is very difficult
|
|
* to print debug info.
|
|
*
|
|
*/
|
|
|
|
static unsigned long _SDR1;
|
|
struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
|
|
EXPORT_SYMBOL_GPL(mmu_psize_defs);
|
|
|
|
struct hash_pte *htab_address;
|
|
unsigned long htab_size_bytes;
|
|
unsigned long htab_hash_mask;
|
|
EXPORT_SYMBOL_GPL(htab_hash_mask);
|
|
int mmu_linear_psize = MMU_PAGE_4K;
|
|
EXPORT_SYMBOL_GPL(mmu_linear_psize);
|
|
int mmu_virtual_psize = MMU_PAGE_4K;
|
|
int mmu_vmalloc_psize = MMU_PAGE_4K;
|
|
#ifdef CONFIG_SPARSEMEM_VMEMMAP
|
|
int mmu_vmemmap_psize = MMU_PAGE_4K;
|
|
#endif
|
|
int mmu_io_psize = MMU_PAGE_4K;
|
|
int mmu_kernel_ssize = MMU_SEGSIZE_256M;
|
|
EXPORT_SYMBOL_GPL(mmu_kernel_ssize);
|
|
int mmu_highuser_ssize = MMU_SEGSIZE_256M;
|
|
u16 mmu_slb_size = 64;
|
|
EXPORT_SYMBOL_GPL(mmu_slb_size);
|
|
#ifdef CONFIG_PPC_64K_PAGES
|
|
int mmu_ci_restrictions;
|
|
#endif
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC
|
|
static u8 *linear_map_hash_slots;
|
|
static unsigned long linear_map_hash_count;
|
|
static DEFINE_SPINLOCK(linear_map_hash_lock);
|
|
#endif /* CONFIG_DEBUG_PAGEALLOC */
|
|
struct mmu_hash_ops mmu_hash_ops;
|
|
EXPORT_SYMBOL(mmu_hash_ops);
|
|
|
|
/* There are definitions of page sizes arrays to be used when none
|
|
* is provided by the firmware.
|
|
*/
|
|
|
|
/* Pre-POWER4 CPUs (4k pages only)
|
|
*/
|
|
static struct mmu_psize_def mmu_psize_defaults_old[] = {
|
|
[MMU_PAGE_4K] = {
|
|
.shift = 12,
|
|
.sllp = 0,
|
|
.penc = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
|
|
.avpnm = 0,
|
|
.tlbiel = 0,
|
|
},
|
|
};
|
|
|
|
/* POWER4, GPUL, POWER5
|
|
*
|
|
* Support for 16Mb large pages
|
|
*/
|
|
static struct mmu_psize_def mmu_psize_defaults_gp[] = {
|
|
[MMU_PAGE_4K] = {
|
|
.shift = 12,
|
|
.sllp = 0,
|
|
.penc = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
|
|
.avpnm = 0,
|
|
.tlbiel = 1,
|
|
},
|
|
[MMU_PAGE_16M] = {
|
|
.shift = 24,
|
|
.sllp = SLB_VSID_L,
|
|
.penc = {[0 ... MMU_PAGE_16M - 1] = -1, [MMU_PAGE_16M] = 0,
|
|
[MMU_PAGE_16M + 1 ... MMU_PAGE_COUNT - 1] = -1 },
|
|
.avpnm = 0x1UL,
|
|
.tlbiel = 0,
|
|
},
|
|
};
|
|
|
|
/*
|
|
* 'R' and 'C' update notes:
|
|
* - Under pHyp or KVM, the updatepp path will not set C, thus it *will*
|
|
* create writeable HPTEs without C set, because the hcall H_PROTECT
|
|
* that we use in that case will not update C
|
|
* - The above is however not a problem, because we also don't do that
|
|
* fancy "no flush" variant of eviction and we use H_REMOVE which will
|
|
* do the right thing and thus we don't have the race I described earlier
|
|
*
|
|
* - Under bare metal, we do have the race, so we need R and C set
|
|
* - We make sure R is always set and never lost
|
|
* - C is _PAGE_DIRTY, and *should* always be set for a writeable mapping
|
|
*/
|
|
unsigned long htab_convert_pte_flags(unsigned long pteflags)
|
|
{
|
|
unsigned long rflags = 0;
|
|
|
|
/* _PAGE_EXEC -> NOEXEC */
|
|
if ((pteflags & _PAGE_EXEC) == 0)
|
|
rflags |= HPTE_R_N;
|
|
/*
|
|
* PPP bits:
|
|
* Linux uses slb key 0 for kernel and 1 for user.
|
|
* kernel RW areas are mapped with PPP=0b000
|
|
* User area is mapped with PPP=0b010 for read/write
|
|
* or PPP=0b011 for read-only (including writeable but clean pages).
|
|
*/
|
|
if (pteflags & _PAGE_PRIVILEGED) {
|
|
/*
|
|
* Kernel read only mapped with ppp bits 0b110
|
|
*/
|
|
if (!(pteflags & _PAGE_WRITE))
|
|
rflags |= (HPTE_R_PP0 | 0x2);
|
|
} else {
|
|
if (pteflags & _PAGE_RWX)
|
|
rflags |= 0x2;
|
|
if (!((pteflags & _PAGE_WRITE) && (pteflags & _PAGE_DIRTY)))
|
|
rflags |= 0x1;
|
|
}
|
|
/*
|
|
* We can't allow hardware to update hpte bits. Hence always
|
|
* set 'R' bit and set 'C' if it is a write fault
|
|
*/
|
|
rflags |= HPTE_R_R;
|
|
|
|
if (pteflags & _PAGE_DIRTY)
|
|
rflags |= HPTE_R_C;
|
|
/*
|
|
* Add in WIG bits
|
|
*/
|
|
|
|
if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_TOLERANT)
|
|
rflags |= HPTE_R_I;
|
|
else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_NON_IDEMPOTENT)
|
|
rflags |= (HPTE_R_I | HPTE_R_G);
|
|
else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO)
|
|
rflags |= (HPTE_R_W | HPTE_R_I | HPTE_R_M);
|
|
else
|
|
/*
|
|
* Add memory coherence if cache inhibited is not set
|
|
*/
|
|
rflags |= HPTE_R_M;
|
|
|
|
return rflags;
|
|
}
|
|
|
|
int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
|
|
unsigned long pstart, unsigned long prot,
|
|
int psize, int ssize)
|
|
{
|
|
unsigned long vaddr, paddr;
|
|
unsigned int step, shift;
|
|
int ret = 0;
|
|
|
|
shift = mmu_psize_defs[psize].shift;
|
|
step = 1 << shift;
|
|
|
|
prot = htab_convert_pte_flags(prot);
|
|
|
|
DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n",
|
|
vstart, vend, pstart, prot, psize, ssize);
|
|
|
|
for (vaddr = vstart, paddr = pstart; vaddr < vend;
|
|
vaddr += step, paddr += step) {
|
|
unsigned long hash, hpteg;
|
|
unsigned long vsid = get_kernel_vsid(vaddr, ssize);
|
|
unsigned long vpn = hpt_vpn(vaddr, vsid, ssize);
|
|
unsigned long tprot = prot;
|
|
|
|
/*
|
|
* If we hit a bad address return error.
|
|
*/
|
|
if (!vsid)
|
|
return -1;
|
|
/* Make kernel text executable */
|
|
if (overlaps_kernel_text(vaddr, vaddr + step))
|
|
tprot &= ~HPTE_R_N;
|
|
|
|
/* Make kvm guest trampolines executable */
|
|
if (overlaps_kvm_tmp(vaddr, vaddr + step))
|
|
tprot &= ~HPTE_R_N;
|
|
|
|
/*
|
|
* If relocatable, check if it overlaps interrupt vectors that
|
|
* are copied down to real 0. For relocatable kernel
|
|
* (e.g. kdump case) we copy interrupt vectors down to real
|
|
* address 0. Mark that region as executable. This is
|
|
* because on p8 system with relocation on exception feature
|
|
* enabled, exceptions are raised with MMU (IR=DR=1) ON. Hence
|
|
* in order to execute the interrupt handlers in virtual
|
|
* mode the vector region need to be marked as executable.
|
|
*/
|
|
if ((PHYSICAL_START > MEMORY_START) &&
|
|
overlaps_interrupt_vector_text(vaddr, vaddr + step))
|
|
tprot &= ~HPTE_R_N;
|
|
|
|
hash = hpt_hash(vpn, shift, ssize);
|
|
hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
|
|
|
|
BUG_ON(!mmu_hash_ops.hpte_insert);
|
|
ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot,
|
|
HPTE_V_BOLTED, psize, psize,
|
|
ssize);
|
|
|
|
if (ret < 0)
|
|
break;
|
|
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC
|
|
if (debug_pagealloc_enabled() &&
|
|
(paddr >> PAGE_SHIFT) < linear_map_hash_count)
|
|
linear_map_hash_slots[paddr >> PAGE_SHIFT] = ret | 0x80;
|
|
#endif /* CONFIG_DEBUG_PAGEALLOC */
|
|
}
|
|
return ret < 0 ? ret : 0;
|
|
}
|
|
|
|
int htab_remove_mapping(unsigned long vstart, unsigned long vend,
|
|
int psize, int ssize)
|
|
{
|
|
unsigned long vaddr;
|
|
unsigned int step, shift;
|
|
int rc;
|
|
int ret = 0;
|
|
|
|
shift = mmu_psize_defs[psize].shift;
|
|
step = 1 << shift;
|
|
|
|
if (!mmu_hash_ops.hpte_removebolted)
|
|
return -ENODEV;
|
|
|
|
for (vaddr = vstart; vaddr < vend; vaddr += step) {
|
|
rc = mmu_hash_ops.hpte_removebolted(vaddr, psize, ssize);
|
|
if (rc == -ENOENT) {
|
|
ret = -ENOENT;
|
|
continue;
|
|
}
|
|
if (rc < 0)
|
|
return rc;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool disable_1tb_segments = false;
|
|
|
|
static int __init parse_disable_1tb_segments(char *p)
|
|
{
|
|
disable_1tb_segments = true;
|
|
return 0;
|
|
}
|
|
early_param("disable_1tb_segments", parse_disable_1tb_segments);
|
|
|
|
static int __init htab_dt_scan_seg_sizes(unsigned long node,
|
|
const char *uname, int depth,
|
|
void *data)
|
|
{
|
|
const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
|
|
const __be32 *prop;
|
|
int size = 0;
|
|
|
|
/* We are scanning "cpu" nodes only */
|
|
if (type == NULL || strcmp(type, "cpu") != 0)
|
|
return 0;
|
|
|
|
prop = of_get_flat_dt_prop(node, "ibm,processor-segment-sizes", &size);
|
|
if (prop == NULL)
|
|
return 0;
|
|
for (; size >= 4; size -= 4, ++prop) {
|
|
if (be32_to_cpu(prop[0]) == 40) {
|
|
DBG("1T segment support detected\n");
|
|
|
|
if (disable_1tb_segments) {
|
|
DBG("1T segments disabled by command line\n");
|
|
break;
|
|
}
|
|
|
|
cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT;
|
|
return 1;
|
|
}
|
|
}
|
|
cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
|
|
return 0;
|
|
}
|
|
|
|
static int __init get_idx_from_shift(unsigned int shift)
|
|
{
|
|
int idx = -1;
|
|
|
|
switch (shift) {
|
|
case 0xc:
|
|
idx = MMU_PAGE_4K;
|
|
break;
|
|
case 0x10:
|
|
idx = MMU_PAGE_64K;
|
|
break;
|
|
case 0x14:
|
|
idx = MMU_PAGE_1M;
|
|
break;
|
|
case 0x18:
|
|
idx = MMU_PAGE_16M;
|
|
break;
|
|
case 0x22:
|
|
idx = MMU_PAGE_16G;
|
|
break;
|
|
}
|
|
return idx;
|
|
}
|
|
|
|
static int __init htab_dt_scan_page_sizes(unsigned long node,
|
|
const char *uname, int depth,
|
|
void *data)
|
|
{
|
|
const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
|
|
const __be32 *prop;
|
|
int size = 0;
|
|
|
|
/* We are scanning "cpu" nodes only */
|
|
if (type == NULL || strcmp(type, "cpu") != 0)
|
|
return 0;
|
|
|
|
prop = of_get_flat_dt_prop(node, "ibm,segment-page-sizes", &size);
|
|
if (!prop)
|
|
return 0;
|
|
|
|
pr_info("Page sizes from device-tree:\n");
|
|
size /= 4;
|
|
cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE);
|
|
while(size > 0) {
|
|
unsigned int base_shift = be32_to_cpu(prop[0]);
|
|
unsigned int slbenc = be32_to_cpu(prop[1]);
|
|
unsigned int lpnum = be32_to_cpu(prop[2]);
|
|
struct mmu_psize_def *def;
|
|
int idx, base_idx;
|
|
|
|
size -= 3; prop += 3;
|
|
base_idx = get_idx_from_shift(base_shift);
|
|
if (base_idx < 0) {
|
|
/* skip the pte encoding also */
|
|
prop += lpnum * 2; size -= lpnum * 2;
|
|
continue;
|
|
}
|
|
def = &mmu_psize_defs[base_idx];
|
|
if (base_idx == MMU_PAGE_16M)
|
|
cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE;
|
|
|
|
def->shift = base_shift;
|
|
if (base_shift <= 23)
|
|
def->avpnm = 0;
|
|
else
|
|
def->avpnm = (1 << (base_shift - 23)) - 1;
|
|
def->sllp = slbenc;
|
|
/*
|
|
* We don't know for sure what's up with tlbiel, so
|
|
* for now we only set it for 4K and 64K pages
|
|
*/
|
|
if (base_idx == MMU_PAGE_4K || base_idx == MMU_PAGE_64K)
|
|
def->tlbiel = 1;
|
|
else
|
|
def->tlbiel = 0;
|
|
|
|
while (size > 0 && lpnum) {
|
|
unsigned int shift = be32_to_cpu(prop[0]);
|
|
int penc = be32_to_cpu(prop[1]);
|
|
|
|
prop += 2; size -= 2;
|
|
lpnum--;
|
|
|
|
idx = get_idx_from_shift(shift);
|
|
if (idx < 0)
|
|
continue;
|
|
|
|
if (penc == -1)
|
|
pr_err("Invalid penc for base_shift=%d "
|
|
"shift=%d\n", base_shift, shift);
|
|
|
|
def->penc[idx] = penc;
|
|
pr_info("base_shift=%d: shift=%d, sllp=0x%04lx,"
|
|
" avpnm=0x%08lx, tlbiel=%d, penc=%d\n",
|
|
base_shift, shift, def->sllp,
|
|
def->avpnm, def->tlbiel, def->penc[idx]);
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
#ifdef CONFIG_HUGETLB_PAGE
|
|
/* Scan for 16G memory blocks that have been set aside for huge pages
|
|
* and reserve those blocks for 16G huge pages.
|
|
*/
|
|
static int __init htab_dt_scan_hugepage_blocks(unsigned long node,
|
|
const char *uname, int depth,
|
|
void *data) {
|
|
const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
|
|
const __be64 *addr_prop;
|
|
const __be32 *page_count_prop;
|
|
unsigned int expected_pages;
|
|
long unsigned int phys_addr;
|
|
long unsigned int block_size;
|
|
|
|
/* We are scanning "memory" nodes only */
|
|
if (type == NULL || strcmp(type, "memory") != 0)
|
|
return 0;
|
|
|
|
/* This property is the log base 2 of the number of virtual pages that
|
|
* will represent this memory block. */
|
|
page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL);
|
|
if (page_count_prop == NULL)
|
|
return 0;
|
|
expected_pages = (1 << be32_to_cpu(page_count_prop[0]));
|
|
addr_prop = of_get_flat_dt_prop(node, "reg", NULL);
|
|
if (addr_prop == NULL)
|
|
return 0;
|
|
phys_addr = be64_to_cpu(addr_prop[0]);
|
|
block_size = be64_to_cpu(addr_prop[1]);
|
|
if (block_size != (16 * GB))
|
|
return 0;
|
|
printk(KERN_INFO "Huge page(16GB) memory: "
|
|
"addr = 0x%lX size = 0x%lX pages = %d\n",
|
|
phys_addr, block_size, expected_pages);
|
|
if (phys_addr + (16 * GB) <= memblock_end_of_DRAM()) {
|
|
memblock_reserve(phys_addr, block_size * expected_pages);
|
|
add_gpage(phys_addr, block_size, expected_pages);
|
|
}
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_HUGETLB_PAGE */
|
|
|
|
static void mmu_psize_set_default_penc(void)
|
|
{
|
|
int bpsize, apsize;
|
|
for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++)
|
|
for (apsize = 0; apsize < MMU_PAGE_COUNT; apsize++)
|
|
mmu_psize_defs[bpsize].penc[apsize] = -1;
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_64K_PAGES
|
|
|
|
static bool might_have_hea(void)
|
|
{
|
|
/*
|
|
* The HEA ethernet adapter requires awareness of the
|
|
* GX bus. Without that awareness we can easily assume
|
|
* we will never see an HEA ethernet device.
|
|
*/
|
|
#ifdef CONFIG_IBMEBUS
|
|
return !cpu_has_feature(CPU_FTR_ARCH_207S) &&
|
|
!firmware_has_feature(FW_FEATURE_SPLPAR);
|
|
#else
|
|
return false;
|
|
#endif
|
|
}
|
|
|
|
#endif /* #ifdef CONFIG_PPC_64K_PAGES */
|
|
|
|
static void __init htab_scan_page_sizes(void)
|
|
{
|
|
int rc;
|
|
|
|
/* se the invalid penc to -1 */
|
|
mmu_psize_set_default_penc();
|
|
|
|
/* Default to 4K pages only */
|
|
memcpy(mmu_psize_defs, mmu_psize_defaults_old,
|
|
sizeof(mmu_psize_defaults_old));
|
|
|
|
/*
|
|
* Try to find the available page sizes in the device-tree
|
|
*/
|
|
rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL);
|
|
if (rc == 0 && early_mmu_has_feature(MMU_FTR_16M_PAGE)) {
|
|
/*
|
|
* Nothing in the device-tree, but the CPU supports 16M pages,
|
|
* so let's fallback on a known size list for 16M capable CPUs.
|
|
*/
|
|
memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
|
|
sizeof(mmu_psize_defaults_gp));
|
|
}
|
|
|
|
#ifdef CONFIG_HUGETLB_PAGE
|
|
/* Reserve 16G huge page memory sections for huge pages */
|
|
of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL);
|
|
#endif /* CONFIG_HUGETLB_PAGE */
|
|
}
|
|
|
|
static void __init htab_init_page_sizes(void)
|
|
{
|
|
if (!debug_pagealloc_enabled()) {
|
|
/*
|
|
* Pick a size for the linear mapping. Currently, we only
|
|
* support 16M, 1M and 4K which is the default
|
|
*/
|
|
if (mmu_psize_defs[MMU_PAGE_16M].shift)
|
|
mmu_linear_psize = MMU_PAGE_16M;
|
|
else if (mmu_psize_defs[MMU_PAGE_1M].shift)
|
|
mmu_linear_psize = MMU_PAGE_1M;
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_64K_PAGES
|
|
/*
|
|
* Pick a size for the ordinary pages. Default is 4K, we support
|
|
* 64K for user mappings and vmalloc if supported by the processor.
|
|
* We only use 64k for ioremap if the processor
|
|
* (and firmware) support cache-inhibited large pages.
|
|
* If not, we use 4k and set mmu_ci_restrictions so that
|
|
* hash_page knows to switch processes that use cache-inhibited
|
|
* mappings to 4k pages.
|
|
*/
|
|
if (mmu_psize_defs[MMU_PAGE_64K].shift) {
|
|
mmu_virtual_psize = MMU_PAGE_64K;
|
|
mmu_vmalloc_psize = MMU_PAGE_64K;
|
|
if (mmu_linear_psize == MMU_PAGE_4K)
|
|
mmu_linear_psize = MMU_PAGE_64K;
|
|
if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) {
|
|
/*
|
|
* When running on pSeries using 64k pages for ioremap
|
|
* would stop us accessing the HEA ethernet. So if we
|
|
* have the chance of ever seeing one, stay at 4k.
|
|
*/
|
|
if (!might_have_hea())
|
|
mmu_io_psize = MMU_PAGE_64K;
|
|
} else
|
|
mmu_ci_restrictions = 1;
|
|
}
|
|
#endif /* CONFIG_PPC_64K_PAGES */
|
|
|
|
#ifdef CONFIG_SPARSEMEM_VMEMMAP
|
|
/* We try to use 16M pages for vmemmap if that is supported
|
|
* and we have at least 1G of RAM at boot
|
|
*/
|
|
if (mmu_psize_defs[MMU_PAGE_16M].shift &&
|
|
memblock_phys_mem_size() >= 0x40000000)
|
|
mmu_vmemmap_psize = MMU_PAGE_16M;
|
|
else if (mmu_psize_defs[MMU_PAGE_64K].shift)
|
|
mmu_vmemmap_psize = MMU_PAGE_64K;
|
|
else
|
|
mmu_vmemmap_psize = MMU_PAGE_4K;
|
|
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
|
|
|
|
printk(KERN_DEBUG "Page orders: linear mapping = %d, "
|
|
"virtual = %d, io = %d"
|
|
#ifdef CONFIG_SPARSEMEM_VMEMMAP
|
|
", vmemmap = %d"
|
|
#endif
|
|
"\n",
|
|
mmu_psize_defs[mmu_linear_psize].shift,
|
|
mmu_psize_defs[mmu_virtual_psize].shift,
|
|
mmu_psize_defs[mmu_io_psize].shift
|
|
#ifdef CONFIG_SPARSEMEM_VMEMMAP
|
|
,mmu_psize_defs[mmu_vmemmap_psize].shift
|
|
#endif
|
|
);
|
|
}
|
|
|
|
static int __init htab_dt_scan_pftsize(unsigned long node,
|
|
const char *uname, int depth,
|
|
void *data)
|
|
{
|
|
const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
|
|
const __be32 *prop;
|
|
|
|
/* We are scanning "cpu" nodes only */
|
|
if (type == NULL || strcmp(type, "cpu") != 0)
|
|
return 0;
|
|
|
|
prop = of_get_flat_dt_prop(node, "ibm,pft-size", NULL);
|
|
if (prop != NULL) {
|
|
/* pft_size[0] is the NUMA CEC cookie */
|
|
ppc64_pft_size = be32_to_cpu(prop[1]);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
unsigned htab_shift_for_mem_size(unsigned long mem_size)
|
|
{
|
|
unsigned memshift = __ilog2(mem_size);
|
|
unsigned pshift = mmu_psize_defs[mmu_virtual_psize].shift;
|
|
unsigned pteg_shift;
|
|
|
|
/* round mem_size up to next power of 2 */
|
|
if ((1UL << memshift) < mem_size)
|
|
memshift += 1;
|
|
|
|
/* aim for 2 pages / pteg */
|
|
pteg_shift = memshift - (pshift + 1);
|
|
|
|
/*
|
|
* 2^11 PTEGS of 128 bytes each, ie. 2^18 bytes is the minimum htab
|
|
* size permitted by the architecture.
|
|
*/
|
|
return max(pteg_shift + 7, 18U);
|
|
}
|
|
|
|
static unsigned long __init htab_get_table_size(void)
|
|
{
|
|
/* If hash size isn't already provided by the platform, we try to
|
|
* retrieve it from the device-tree. If it's not there neither, we
|
|
* calculate it now based on the total RAM size
|
|
*/
|
|
if (ppc64_pft_size == 0)
|
|
of_scan_flat_dt(htab_dt_scan_pftsize, NULL);
|
|
if (ppc64_pft_size)
|
|
return 1UL << ppc64_pft_size;
|
|
|
|
return 1UL << htab_shift_for_mem_size(memblock_phys_mem_size());
|
|
}
|
|
|
|
#ifdef CONFIG_MEMORY_HOTPLUG
|
|
int create_section_mapping(unsigned long start, unsigned long end)
|
|
{
|
|
int rc = htab_bolt_mapping(start, end, __pa(start),
|
|
pgprot_val(PAGE_KERNEL), mmu_linear_psize,
|
|
mmu_kernel_ssize);
|
|
|
|
if (rc < 0) {
|
|
int rc2 = htab_remove_mapping(start, end, mmu_linear_psize,
|
|
mmu_kernel_ssize);
|
|
BUG_ON(rc2 && (rc2 != -ENOENT));
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
int remove_section_mapping(unsigned long start, unsigned long end)
|
|
{
|
|
int rc = htab_remove_mapping(start, end, mmu_linear_psize,
|
|
mmu_kernel_ssize);
|
|
WARN_ON(rc < 0);
|
|
return rc;
|
|
}
|
|
#endif /* CONFIG_MEMORY_HOTPLUG */
|
|
|
|
static void __init hash_init_partition_table(phys_addr_t hash_table,
|
|
unsigned long htab_size)
|
|
{
|
|
unsigned long ps_field;
|
|
unsigned long patb_size = 1UL << PATB_SIZE_SHIFT;
|
|
|
|
/*
|
|
* slb llp encoding for the page size used in VPM real mode.
|
|
* We can ignore that for lpid 0
|
|
*/
|
|
ps_field = 0;
|
|
htab_size = __ilog2(htab_size) - 18;
|
|
|
|
BUILD_BUG_ON_MSG((PATB_SIZE_SHIFT > 24), "Partition table size too large.");
|
|
partition_tb = __va(memblock_alloc_base(patb_size, patb_size,
|
|
MEMBLOCK_ALLOC_ANYWHERE));
|
|
|
|
/* Initialize the Partition Table with no entries */
|
|
memset((void *)partition_tb, 0, patb_size);
|
|
partition_tb->patb0 = cpu_to_be64(ps_field | hash_table | htab_size);
|
|
/*
|
|
* FIXME!! This should be done via update_partition table
|
|
* For now UPRT is 0 for us.
|
|
*/
|
|
partition_tb->patb1 = 0;
|
|
pr_info("Partition table %p\n", partition_tb);
|
|
/*
|
|
* update partition table control register,
|
|
* 64 K size.
|
|
*/
|
|
mtspr(SPRN_PTCR, __pa(partition_tb) | (PATB_SIZE_SHIFT - 12));
|
|
|
|
}
|
|
|
|
static void __init htab_initialize(void)
|
|
{
|
|
unsigned long table;
|
|
unsigned long pteg_count;
|
|
unsigned long prot;
|
|
unsigned long base = 0, size = 0;
|
|
struct memblock_region *reg;
|
|
|
|
DBG(" -> htab_initialize()\n");
|
|
|
|
if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) {
|
|
mmu_kernel_ssize = MMU_SEGSIZE_1T;
|
|
mmu_highuser_ssize = MMU_SEGSIZE_1T;
|
|
printk(KERN_INFO "Using 1TB segments\n");
|
|
}
|
|
|
|
/*
|
|
* Calculate the required size of the htab. We want the number of
|
|
* PTEGs to equal one half the number of real pages.
|
|
*/
|
|
htab_size_bytes = htab_get_table_size();
|
|
pteg_count = htab_size_bytes >> 7;
|
|
|
|
htab_hash_mask = pteg_count - 1;
|
|
|
|
if (firmware_has_feature(FW_FEATURE_LPAR) ||
|
|
firmware_has_feature(FW_FEATURE_PS3_LV1)) {
|
|
/* Using a hypervisor which owns the htab */
|
|
htab_address = NULL;
|
|
_SDR1 = 0;
|
|
#ifdef CONFIG_FA_DUMP
|
|
/*
|
|
* If firmware assisted dump is active firmware preserves
|
|
* the contents of htab along with entire partition memory.
|
|
* Clear the htab if firmware assisted dump is active so
|
|
* that we dont end up using old mappings.
|
|
*/
|
|
if (is_fadump_active() && mmu_hash_ops.hpte_clear_all)
|
|
mmu_hash_ops.hpte_clear_all();
|
|
#endif
|
|
} else {
|
|
unsigned long limit = MEMBLOCK_ALLOC_ANYWHERE;
|
|
|
|
#ifdef CONFIG_PPC_CELL
|
|
/*
|
|
* Cell may require the hash table down low when using the
|
|
* Axon IOMMU in order to fit the dynamic region over it, see
|
|
* comments in cell/iommu.c
|
|
*/
|
|
if (fdt_subnode_offset(initial_boot_params, 0, "axon") > 0) {
|
|
limit = 0x80000000;
|
|
pr_info("Hash table forced below 2G for Axon IOMMU\n");
|
|
}
|
|
#endif /* CONFIG_PPC_CELL */
|
|
|
|
table = memblock_alloc_base(htab_size_bytes, htab_size_bytes,
|
|
limit);
|
|
|
|
DBG("Hash table allocated at %lx, size: %lx\n", table,
|
|
htab_size_bytes);
|
|
|
|
htab_address = __va(table);
|
|
|
|
/* htab absolute addr + encoded htabsize */
|
|
_SDR1 = table + __ilog2(htab_size_bytes) - 18;
|
|
|
|
/* Initialize the HPT with no entries */
|
|
memset((void *)table, 0, htab_size_bytes);
|
|
|
|
if (!cpu_has_feature(CPU_FTR_ARCH_300))
|
|
/* Set SDR1 */
|
|
mtspr(SPRN_SDR1, _SDR1);
|
|
else
|
|
hash_init_partition_table(table, htab_size_bytes);
|
|
}
|
|
|
|
prot = pgprot_val(PAGE_KERNEL);
|
|
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC
|
|
if (debug_pagealloc_enabled()) {
|
|
linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT;
|
|
linear_map_hash_slots = __va(memblock_alloc_base(
|
|
linear_map_hash_count, 1, ppc64_rma_size));
|
|
memset(linear_map_hash_slots, 0, linear_map_hash_count);
|
|
}
|
|
#endif /* CONFIG_DEBUG_PAGEALLOC */
|
|
|
|
/* On U3 based machines, we need to reserve the DART area and
|
|
* _NOT_ map it to avoid cache paradoxes as it's remapped non
|
|
* cacheable later on
|
|
*/
|
|
|
|
/* create bolted the linear mapping in the hash table */
|
|
for_each_memblock(memory, reg) {
|
|
base = (unsigned long)__va(reg->base);
|
|
size = reg->size;
|
|
|
|
DBG("creating mapping for region: %lx..%lx (prot: %lx)\n",
|
|
base, size, prot);
|
|
|
|
BUG_ON(htab_bolt_mapping(base, base + size, __pa(base),
|
|
prot, mmu_linear_psize, mmu_kernel_ssize));
|
|
}
|
|
memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
|
|
|
|
/*
|
|
* If we have a memory_limit and we've allocated TCEs then we need to
|
|
* explicitly map the TCE area at the top of RAM. We also cope with the
|
|
* case that the TCEs start below memory_limit.
|
|
* tce_alloc_start/end are 16MB aligned so the mapping should work
|
|
* for either 4K or 16MB pages.
|
|
*/
|
|
if (tce_alloc_start) {
|
|
tce_alloc_start = (unsigned long)__va(tce_alloc_start);
|
|
tce_alloc_end = (unsigned long)__va(tce_alloc_end);
|
|
|
|
if (base + size >= tce_alloc_start)
|
|
tce_alloc_start = base + size + 1;
|
|
|
|
BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end,
|
|
__pa(tce_alloc_start), prot,
|
|
mmu_linear_psize, mmu_kernel_ssize));
|
|
}
|
|
|
|
|
|
DBG(" <- htab_initialize()\n");
|
|
}
|
|
#undef KB
|
|
#undef MB
|
|
|
|
void __init hash__early_init_devtree(void)
|
|
{
|
|
/* Initialize segment sizes */
|
|
of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL);
|
|
|
|
/* Initialize page sizes */
|
|
htab_scan_page_sizes();
|
|
}
|
|
|
|
void __init hash__early_init_mmu(void)
|
|
{
|
|
htab_init_page_sizes();
|
|
|
|
/*
|
|
* initialize page table size
|
|
*/
|
|
__pte_frag_nr = H_PTE_FRAG_NR;
|
|
__pte_frag_size_shift = H_PTE_FRAG_SIZE_SHIFT;
|
|
|
|
__pte_index_size = H_PTE_INDEX_SIZE;
|
|
__pmd_index_size = H_PMD_INDEX_SIZE;
|
|
__pud_index_size = H_PUD_INDEX_SIZE;
|
|
__pgd_index_size = H_PGD_INDEX_SIZE;
|
|
__pmd_cache_index = H_PMD_CACHE_INDEX;
|
|
__pte_table_size = H_PTE_TABLE_SIZE;
|
|
__pmd_table_size = H_PMD_TABLE_SIZE;
|
|
__pud_table_size = H_PUD_TABLE_SIZE;
|
|
__pgd_table_size = H_PGD_TABLE_SIZE;
|
|
/*
|
|
* 4k use hugepd format, so for hash set then to
|
|
* zero
|
|
*/
|
|
__pmd_val_bits = 0;
|
|
__pud_val_bits = 0;
|
|
__pgd_val_bits = 0;
|
|
|
|
__kernel_virt_start = H_KERN_VIRT_START;
|
|
__kernel_virt_size = H_KERN_VIRT_SIZE;
|
|
__vmalloc_start = H_VMALLOC_START;
|
|
__vmalloc_end = H_VMALLOC_END;
|
|
vmemmap = (struct page *)H_VMEMMAP_BASE;
|
|
ioremap_bot = IOREMAP_BASE;
|
|
|
|
#ifdef CONFIG_PCI
|
|
pci_io_base = ISA_IO_BASE;
|
|
#endif
|
|
|
|
/* Select appropriate backend */
|
|
if (firmware_has_feature(FW_FEATURE_PS3_LV1))
|
|
ps3_early_mm_init();
|
|
else if (firmware_has_feature(FW_FEATURE_LPAR))
|
|
hpte_init_pseries();
|
|
else if (IS_ENABLED(CONFIG_PPC_NATIVE))
|
|
hpte_init_native();
|
|
|
|
if (!mmu_hash_ops.hpte_insert)
|
|
panic("hash__early_init_mmu: No MMU hash ops defined!\n");
|
|
|
|
/* Initialize the MMU Hash table and create the linear mapping
|
|
* of memory. Has to be done before SLB initialization as this is
|
|
* currently where the page size encoding is obtained.
|
|
*/
|
|
htab_initialize();
|
|
|
|
pr_info("Initializing hash mmu with SLB\n");
|
|
/* Initialize SLB management */
|
|
slb_initialize();
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
void hash__early_init_mmu_secondary(void)
|
|
{
|
|
/* Initialize hash table for that CPU */
|
|
if (!firmware_has_feature(FW_FEATURE_LPAR)) {
|
|
if (!cpu_has_feature(CPU_FTR_ARCH_300))
|
|
mtspr(SPRN_SDR1, _SDR1);
|
|
else
|
|
mtspr(SPRN_PTCR,
|
|
__pa(partition_tb) | (PATB_SIZE_SHIFT - 12));
|
|
}
|
|
/* Initialize SLB */
|
|
slb_initialize();
|
|
}
|
|
#endif /* CONFIG_SMP */
|
|
|
|
/*
|
|
* Called by asm hashtable.S for doing lazy icache flush
|
|
*/
|
|
unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
|
|
{
|
|
struct page *page;
|
|
|
|
if (!pfn_valid(pte_pfn(pte)))
|
|
return pp;
|
|
|
|
page = pte_page(pte);
|
|
|
|
/* page is dirty */
|
|
if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
|
|
if (trap == 0x400) {
|
|
flush_dcache_icache_page(page);
|
|
set_bit(PG_arch_1, &page->flags);
|
|
} else
|
|
pp |= HPTE_R_N;
|
|
}
|
|
return pp;
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_MM_SLICES
|
|
static unsigned int get_paca_psize(unsigned long addr)
|
|
{
|
|
u64 lpsizes;
|
|
unsigned char *hpsizes;
|
|
unsigned long index, mask_index;
|
|
|
|
if (addr < SLICE_LOW_TOP) {
|
|
lpsizes = get_paca()->mm_ctx_low_slices_psize;
|
|
index = GET_LOW_SLICE_INDEX(addr);
|
|
return (lpsizes >> (index * 4)) & 0xF;
|
|
}
|
|
hpsizes = get_paca()->mm_ctx_high_slices_psize;
|
|
index = GET_HIGH_SLICE_INDEX(addr);
|
|
mask_index = index & 0x1;
|
|
return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xF;
|
|
}
|
|
|
|
#else
|
|
unsigned int get_paca_psize(unsigned long addr)
|
|
{
|
|
return get_paca()->mm_ctx_user_psize;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Demote a segment to using 4k pages.
|
|
* For now this makes the whole process use 4k pages.
|
|
*/
|
|
#ifdef CONFIG_PPC_64K_PAGES
|
|
void demote_segment_4k(struct mm_struct *mm, unsigned long addr)
|
|
{
|
|
if (get_slice_psize(mm, addr) == MMU_PAGE_4K)
|
|
return;
|
|
slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K);
|
|
copro_flush_all_slbs(mm);
|
|
if ((get_paca_psize(addr) != MMU_PAGE_4K) && (current->mm == mm)) {
|
|
|
|
copy_mm_to_paca(&mm->context);
|
|
slb_flush_and_rebolt();
|
|
}
|
|
}
|
|
#endif /* CONFIG_PPC_64K_PAGES */
|
|
|
|
#ifdef CONFIG_PPC_SUBPAGE_PROT
|
|
/*
|
|
* This looks up a 2-bit protection code for a 4k subpage of a 64k page.
|
|
* Userspace sets the subpage permissions using the subpage_prot system call.
|
|
*
|
|
* Result is 0: full permissions, _PAGE_RW: read-only,
|
|
* _PAGE_RWX: no access.
|
|
*/
|
|
static int subpage_protection(struct mm_struct *mm, unsigned long ea)
|
|
{
|
|
struct subpage_prot_table *spt = &mm->context.spt;
|
|
u32 spp = 0;
|
|
u32 **sbpm, *sbpp;
|
|
|
|
if (ea >= spt->maxaddr)
|
|
return 0;
|
|
if (ea < 0x100000000UL) {
|
|
/* addresses below 4GB use spt->low_prot */
|
|
sbpm = spt->low_prot;
|
|
} else {
|
|
sbpm = spt->protptrs[ea >> SBP_L3_SHIFT];
|
|
if (!sbpm)
|
|
return 0;
|
|
}
|
|
sbpp = sbpm[(ea >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)];
|
|
if (!sbpp)
|
|
return 0;
|
|
spp = sbpp[(ea >> PAGE_SHIFT) & (SBP_L1_COUNT - 1)];
|
|
|
|
/* extract 2-bit bitfield for this 4k subpage */
|
|
spp >>= 30 - 2 * ((ea >> 12) & 0xf);
|
|
|
|
/*
|
|
* 0 -> full premission
|
|
* 1 -> Read only
|
|
* 2 -> no access.
|
|
* We return the flag that need to be cleared.
|
|
*/
|
|
spp = ((spp & 2) ? _PAGE_RWX : 0) | ((spp & 1) ? _PAGE_WRITE : 0);
|
|
return spp;
|
|
}
|
|
|
|
#else /* CONFIG_PPC_SUBPAGE_PROT */
|
|
static inline int subpage_protection(struct mm_struct *mm, unsigned long ea)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
void hash_failure_debug(unsigned long ea, unsigned long access,
|
|
unsigned long vsid, unsigned long trap,
|
|
int ssize, int psize, int lpsize, unsigned long pte)
|
|
{
|
|
if (!printk_ratelimit())
|
|
return;
|
|
pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n",
|
|
ea, access, current->comm);
|
|
pr_info(" trap=0x%lx vsid=0x%lx ssize=%d base psize=%d psize %d pte=0x%lx\n",
|
|
trap, vsid, ssize, psize, lpsize, pte);
|
|
}
|
|
|
|
static void check_paca_psize(unsigned long ea, struct mm_struct *mm,
|
|
int psize, bool user_region)
|
|
{
|
|
if (user_region) {
|
|
if (psize != get_paca_psize(ea)) {
|
|
copy_mm_to_paca(&mm->context);
|
|
slb_flush_and_rebolt();
|
|
}
|
|
} else if (get_paca()->vmalloc_sllp !=
|
|
mmu_psize_defs[mmu_vmalloc_psize].sllp) {
|
|
get_paca()->vmalloc_sllp =
|
|
mmu_psize_defs[mmu_vmalloc_psize].sllp;
|
|
slb_vmalloc_update();
|
|
}
|
|
}
|
|
|
|
/* Result code is:
|
|
* 0 - handled
|
|
* 1 - normal page fault
|
|
* -1 - critical hash insertion error
|
|
* -2 - access not permitted by subpage protection mechanism
|
|
*/
|
|
int hash_page_mm(struct mm_struct *mm, unsigned long ea,
|
|
unsigned long access, unsigned long trap,
|
|
unsigned long flags)
|
|
{
|
|
bool is_thp;
|
|
enum ctx_state prev_state = exception_enter();
|
|
pgd_t *pgdir;
|
|
unsigned long vsid;
|
|
pte_t *ptep;
|
|
unsigned hugeshift;
|
|
const struct cpumask *tmp;
|
|
int rc, user_region = 0;
|
|
int psize, ssize;
|
|
|
|
DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
|
|
ea, access, trap);
|
|
trace_hash_fault(ea, access, trap);
|
|
|
|
/* Get region & vsid */
|
|
switch (REGION_ID(ea)) {
|
|
case USER_REGION_ID:
|
|
user_region = 1;
|
|
if (! mm) {
|
|
DBG_LOW(" user region with no mm !\n");
|
|
rc = 1;
|
|
goto bail;
|
|
}
|
|
psize = get_slice_psize(mm, ea);
|
|
ssize = user_segment_size(ea);
|
|
vsid = get_vsid(mm->context.id, ea, ssize);
|
|
break;
|
|
case VMALLOC_REGION_ID:
|
|
vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
|
|
if (ea < VMALLOC_END)
|
|
psize = mmu_vmalloc_psize;
|
|
else
|
|
psize = mmu_io_psize;
|
|
ssize = mmu_kernel_ssize;
|
|
break;
|
|
default:
|
|
/* Not a valid range
|
|
* Send the problem up to do_page_fault
|
|
*/
|
|
rc = 1;
|
|
goto bail;
|
|
}
|
|
DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
|
|
|
|
/* Bad address. */
|
|
if (!vsid) {
|
|
DBG_LOW("Bad address!\n");
|
|
rc = 1;
|
|
goto bail;
|
|
}
|
|
/* Get pgdir */
|
|
pgdir = mm->pgd;
|
|
if (pgdir == NULL) {
|
|
rc = 1;
|
|
goto bail;
|
|
}
|
|
|
|
/* Check CPU locality */
|
|
tmp = cpumask_of(smp_processor_id());
|
|
if (user_region && cpumask_equal(mm_cpumask(mm), tmp))
|
|
flags |= HPTE_LOCAL_UPDATE;
|
|
|
|
#ifndef CONFIG_PPC_64K_PAGES
|
|
/* If we use 4K pages and our psize is not 4K, then we might
|
|
* be hitting a special driver mapping, and need to align the
|
|
* address before we fetch the PTE.
|
|
*
|
|
* It could also be a hugepage mapping, in which case this is
|
|
* not necessary, but it's not harmful, either.
|
|
*/
|
|
if (psize != MMU_PAGE_4K)
|
|
ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
|
|
#endif /* CONFIG_PPC_64K_PAGES */
|
|
|
|
/* Get PTE and page size from page tables */
|
|
ptep = __find_linux_pte_or_hugepte(pgdir, ea, &is_thp, &hugeshift);
|
|
if (ptep == NULL || !pte_present(*ptep)) {
|
|
DBG_LOW(" no PTE !\n");
|
|
rc = 1;
|
|
goto bail;
|
|
}
|
|
|
|
/* Add _PAGE_PRESENT to the required access perm */
|
|
access |= _PAGE_PRESENT;
|
|
|
|
/* Pre-check access permissions (will be re-checked atomically
|
|
* in __hash_page_XX but this pre-check is a fast path
|
|
*/
|
|
if (!check_pte_access(access, pte_val(*ptep))) {
|
|
DBG_LOW(" no access !\n");
|
|
rc = 1;
|
|
goto bail;
|
|
}
|
|
|
|
if (hugeshift) {
|
|
if (is_thp)
|
|
rc = __hash_page_thp(ea, access, vsid, (pmd_t *)ptep,
|
|
trap, flags, ssize, psize);
|
|
#ifdef CONFIG_HUGETLB_PAGE
|
|
else
|
|
rc = __hash_page_huge(ea, access, vsid, ptep, trap,
|
|
flags, ssize, hugeshift, psize);
|
|
#else
|
|
else {
|
|
/*
|
|
* if we have hugeshift, and is not transhuge with
|
|
* hugetlb disabled, something is really wrong.
|
|
*/
|
|
rc = 1;
|
|
WARN_ON(1);
|
|
}
|
|
#endif
|
|
if (current->mm == mm)
|
|
check_paca_psize(ea, mm, psize, user_region);
|
|
|
|
goto bail;
|
|
}
|
|
|
|
#ifndef CONFIG_PPC_64K_PAGES
|
|
DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep));
|
|
#else
|
|
DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep),
|
|
pte_val(*(ptep + PTRS_PER_PTE)));
|
|
#endif
|
|
/* Do actual hashing */
|
|
#ifdef CONFIG_PPC_64K_PAGES
|
|
/* If H_PAGE_4K_PFN is set, make sure this is a 4k segment */
|
|
if ((pte_val(*ptep) & H_PAGE_4K_PFN) && psize == MMU_PAGE_64K) {
|
|
demote_segment_4k(mm, ea);
|
|
psize = MMU_PAGE_4K;
|
|
}
|
|
|
|
/* If this PTE is non-cacheable and we have restrictions on
|
|
* using non cacheable large pages, then we switch to 4k
|
|
*/
|
|
if (mmu_ci_restrictions && psize == MMU_PAGE_64K && pte_ci(*ptep)) {
|
|
if (user_region) {
|
|
demote_segment_4k(mm, ea);
|
|
psize = MMU_PAGE_4K;
|
|
} else if (ea < VMALLOC_END) {
|
|
/*
|
|
* some driver did a non-cacheable mapping
|
|
* in vmalloc space, so switch vmalloc
|
|
* to 4k pages
|
|
*/
|
|
printk(KERN_ALERT "Reducing vmalloc segment "
|
|
"to 4kB pages because of "
|
|
"non-cacheable mapping\n");
|
|
psize = mmu_vmalloc_psize = MMU_PAGE_4K;
|
|
copro_flush_all_slbs(mm);
|
|
}
|
|
}
|
|
|
|
#endif /* CONFIG_PPC_64K_PAGES */
|
|
|
|
if (current->mm == mm)
|
|
check_paca_psize(ea, mm, psize, user_region);
|
|
|
|
#ifdef CONFIG_PPC_64K_PAGES
|
|
if (psize == MMU_PAGE_64K)
|
|
rc = __hash_page_64K(ea, access, vsid, ptep, trap,
|
|
flags, ssize);
|
|
else
|
|
#endif /* CONFIG_PPC_64K_PAGES */
|
|
{
|
|
int spp = subpage_protection(mm, ea);
|
|
if (access & spp)
|
|
rc = -2;
|
|
else
|
|
rc = __hash_page_4K(ea, access, vsid, ptep, trap,
|
|
flags, ssize, spp);
|
|
}
|
|
|
|
/* Dump some info in case of hash insertion failure, they should
|
|
* never happen so it is really useful to know if/when they do
|
|
*/
|
|
if (rc == -1)
|
|
hash_failure_debug(ea, access, vsid, trap, ssize, psize,
|
|
psize, pte_val(*ptep));
|
|
#ifndef CONFIG_PPC_64K_PAGES
|
|
DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep));
|
|
#else
|
|
DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep),
|
|
pte_val(*(ptep + PTRS_PER_PTE)));
|
|
#endif
|
|
DBG_LOW(" -> rc=%d\n", rc);
|
|
|
|
bail:
|
|
exception_exit(prev_state);
|
|
return rc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(hash_page_mm);
|
|
|
|
int hash_page(unsigned long ea, unsigned long access, unsigned long trap,
|
|
unsigned long dsisr)
|
|
{
|
|
unsigned long flags = 0;
|
|
struct mm_struct *mm = current->mm;
|
|
|
|
if (REGION_ID(ea) == VMALLOC_REGION_ID)
|
|
mm = &init_mm;
|
|
|
|
if (dsisr & DSISR_NOHPTE)
|
|
flags |= HPTE_NOHPTE_UPDATE;
|
|
|
|
return hash_page_mm(mm, ea, access, trap, flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(hash_page);
|
|
|
|
int __hash_page(unsigned long ea, unsigned long msr, unsigned long trap,
|
|
unsigned long dsisr)
|
|
{
|
|
unsigned long access = _PAGE_PRESENT | _PAGE_READ;
|
|
unsigned long flags = 0;
|
|
struct mm_struct *mm = current->mm;
|
|
|
|
if (REGION_ID(ea) == VMALLOC_REGION_ID)
|
|
mm = &init_mm;
|
|
|
|
if (dsisr & DSISR_NOHPTE)
|
|
flags |= HPTE_NOHPTE_UPDATE;
|
|
|
|
if (dsisr & DSISR_ISSTORE)
|
|
access |= _PAGE_WRITE;
|
|
/*
|
|
* We set _PAGE_PRIVILEGED only when
|
|
* kernel mode access kernel space.
|
|
*
|
|
* _PAGE_PRIVILEGED is NOT set
|
|
* 1) when kernel mode access user space
|
|
* 2) user space access kernel space.
|
|
*/
|
|
access |= _PAGE_PRIVILEGED;
|
|
if ((msr & MSR_PR) || (REGION_ID(ea) == USER_REGION_ID))
|
|
access &= ~_PAGE_PRIVILEGED;
|
|
|
|
if (trap == 0x400)
|
|
access |= _PAGE_EXEC;
|
|
|
|
return hash_page_mm(mm, ea, access, trap, flags);
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_MM_SLICES
|
|
static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
|
|
{
|
|
int psize = get_slice_psize(mm, ea);
|
|
|
|
/* We only prefault standard pages for now */
|
|
if (unlikely(psize != mm->context.user_psize))
|
|
return false;
|
|
|
|
/*
|
|
* Don't prefault if subpage protection is enabled for the EA.
|
|
*/
|
|
if (unlikely((psize == MMU_PAGE_4K) && subpage_protection(mm, ea)))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
#else
|
|
static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
|
|
{
|
|
return true;
|
|
}
|
|
#endif
|
|
|
|
void hash_preload(struct mm_struct *mm, unsigned long ea,
|
|
unsigned long access, unsigned long trap)
|
|
{
|
|
int hugepage_shift;
|
|
unsigned long vsid;
|
|
pgd_t *pgdir;
|
|
pte_t *ptep;
|
|
unsigned long flags;
|
|
int rc, ssize, update_flags = 0;
|
|
|
|
BUG_ON(REGION_ID(ea) != USER_REGION_ID);
|
|
|
|
if (!should_hash_preload(mm, ea))
|
|
return;
|
|
|
|
DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx,"
|
|
" trap=%lx\n", mm, mm->pgd, ea, access, trap);
|
|
|
|
/* Get Linux PTE if available */
|
|
pgdir = mm->pgd;
|
|
if (pgdir == NULL)
|
|
return;
|
|
|
|
/* Get VSID */
|
|
ssize = user_segment_size(ea);
|
|
vsid = get_vsid(mm->context.id, ea, ssize);
|
|
if (!vsid)
|
|
return;
|
|
/*
|
|
* Hash doesn't like irqs. Walking linux page table with irq disabled
|
|
* saves us from holding multiple locks.
|
|
*/
|
|
local_irq_save(flags);
|
|
|
|
/*
|
|
* THP pages use update_mmu_cache_pmd. We don't do
|
|
* hash preload there. Hence can ignore THP here
|
|
*/
|
|
ptep = find_linux_pte_or_hugepte(pgdir, ea, NULL, &hugepage_shift);
|
|
if (!ptep)
|
|
goto out_exit;
|
|
|
|
WARN_ON(hugepage_shift);
|
|
#ifdef CONFIG_PPC_64K_PAGES
|
|
/* If either H_PAGE_4K_PFN or cache inhibited is set (and we are on
|
|
* a 64K kernel), then we don't preload, hash_page() will take
|
|
* care of it once we actually try to access the page.
|
|
* That way we don't have to duplicate all of the logic for segment
|
|
* page size demotion here
|
|
*/
|
|
if ((pte_val(*ptep) & H_PAGE_4K_PFN) || pte_ci(*ptep))
|
|
goto out_exit;
|
|
#endif /* CONFIG_PPC_64K_PAGES */
|
|
|
|
/* Is that local to this CPU ? */
|
|
if (cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
|
|
update_flags |= HPTE_LOCAL_UPDATE;
|
|
|
|
/* Hash it in */
|
|
#ifdef CONFIG_PPC_64K_PAGES
|
|
if (mm->context.user_psize == MMU_PAGE_64K)
|
|
rc = __hash_page_64K(ea, access, vsid, ptep, trap,
|
|
update_flags, ssize);
|
|
else
|
|
#endif /* CONFIG_PPC_64K_PAGES */
|
|
rc = __hash_page_4K(ea, access, vsid, ptep, trap, update_flags,
|
|
ssize, subpage_protection(mm, ea));
|
|
|
|
/* Dump some info in case of hash insertion failure, they should
|
|
* never happen so it is really useful to know if/when they do
|
|
*/
|
|
if (rc == -1)
|
|
hash_failure_debug(ea, access, vsid, trap, ssize,
|
|
mm->context.user_psize,
|
|
mm->context.user_psize,
|
|
pte_val(*ptep));
|
|
out_exit:
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
/* WARNING: This is called from hash_low_64.S, if you change this prototype,
|
|
* do not forget to update the assembly call site !
|
|
*/
|
|
void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize,
|
|
unsigned long flags)
|
|
{
|
|
unsigned long hash, index, shift, hidx, slot;
|
|
int local = flags & HPTE_LOCAL_UPDATE;
|
|
|
|
DBG_LOW("flush_hash_page(vpn=%016lx)\n", vpn);
|
|
pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
|
|
hash = hpt_hash(vpn, shift, ssize);
|
|
hidx = __rpte_to_hidx(pte, index);
|
|
if (hidx & _PTEIDX_SECONDARY)
|
|
hash = ~hash;
|
|
slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
|
|
slot += hidx & _PTEIDX_GROUP_IX;
|
|
DBG_LOW(" sub %ld: hash=%lx, hidx=%lx\n", index, slot, hidx);
|
|
/*
|
|
* We use same base page size and actual psize, because we don't
|
|
* use these functions for hugepage
|
|
*/
|
|
mmu_hash_ops.hpte_invalidate(slot, vpn, psize, psize,
|
|
ssize, local);
|
|
} pte_iterate_hashed_end();
|
|
|
|
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
|
|
/* Transactions are not aborted by tlbiel, only tlbie.
|
|
* Without, syncing a page back to a block device w/ PIO could pick up
|
|
* transactional data (bad!) so we force an abort here. Before the
|
|
* sync the page will be made read-only, which will flush_hash_page.
|
|
* BIG ISSUE here: if the kernel uses a page from userspace without
|
|
* unmapping it first, it may see the speculated version.
|
|
*/
|
|
if (local && cpu_has_feature(CPU_FTR_TM) &&
|
|
current->thread.regs &&
|
|
MSR_TM_ACTIVE(current->thread.regs->msr)) {
|
|
tm_enable();
|
|
tm_abort(TM_CAUSE_TLBI);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
void flush_hash_hugepage(unsigned long vsid, unsigned long addr,
|
|
pmd_t *pmdp, unsigned int psize, int ssize,
|
|
unsigned long flags)
|
|
{
|
|
int i, max_hpte_count, valid;
|
|
unsigned long s_addr;
|
|
unsigned char *hpte_slot_array;
|
|
unsigned long hidx, shift, vpn, hash, slot;
|
|
int local = flags & HPTE_LOCAL_UPDATE;
|
|
|
|
s_addr = addr & HPAGE_PMD_MASK;
|
|
hpte_slot_array = get_hpte_slot_array(pmdp);
|
|
/*
|
|
* IF we try to do a HUGE PTE update after a withdraw is done.
|
|
* we will find the below NULL. This happens when we do
|
|
* split_huge_page_pmd
|
|
*/
|
|
if (!hpte_slot_array)
|
|
return;
|
|
|
|
if (mmu_hash_ops.hugepage_invalidate) {
|
|
mmu_hash_ops.hugepage_invalidate(vsid, s_addr, hpte_slot_array,
|
|
psize, ssize, local);
|
|
goto tm_abort;
|
|
}
|
|
/*
|
|
* No bluk hpte removal support, invalidate each entry
|
|
*/
|
|
shift = mmu_psize_defs[psize].shift;
|
|
max_hpte_count = HPAGE_PMD_SIZE >> shift;
|
|
for (i = 0; i < max_hpte_count; i++) {
|
|
/*
|
|
* 8 bits per each hpte entries
|
|
* 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
|
|
*/
|
|
valid = hpte_valid(hpte_slot_array, i);
|
|
if (!valid)
|
|
continue;
|
|
hidx = hpte_hash_index(hpte_slot_array, i);
|
|
|
|
/* get the vpn */
|
|
addr = s_addr + (i * (1ul << shift));
|
|
vpn = hpt_vpn(addr, vsid, ssize);
|
|
hash = hpt_hash(vpn, shift, ssize);
|
|
if (hidx & _PTEIDX_SECONDARY)
|
|
hash = ~hash;
|
|
|
|
slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
|
|
slot += hidx & _PTEIDX_GROUP_IX;
|
|
mmu_hash_ops.hpte_invalidate(slot, vpn, psize,
|
|
MMU_PAGE_16M, ssize, local);
|
|
}
|
|
tm_abort:
|
|
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
|
|
/* Transactions are not aborted by tlbiel, only tlbie.
|
|
* Without, syncing a page back to a block device w/ PIO could pick up
|
|
* transactional data (bad!) so we force an abort here. Before the
|
|
* sync the page will be made read-only, which will flush_hash_page.
|
|
* BIG ISSUE here: if the kernel uses a page from userspace without
|
|
* unmapping it first, it may see the speculated version.
|
|
*/
|
|
if (local && cpu_has_feature(CPU_FTR_TM) &&
|
|
current->thread.regs &&
|
|
MSR_TM_ACTIVE(current->thread.regs->msr)) {
|
|
tm_enable();
|
|
tm_abort(TM_CAUSE_TLBI);
|
|
}
|
|
#endif
|
|
return;
|
|
}
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
|
|
void flush_hash_range(unsigned long number, int local)
|
|
{
|
|
if (mmu_hash_ops.flush_hash_range)
|
|
mmu_hash_ops.flush_hash_range(number, local);
|
|
else {
|
|
int i;
|
|
struct ppc64_tlb_batch *batch =
|
|
this_cpu_ptr(&ppc64_tlb_batch);
|
|
|
|
for (i = 0; i < number; i++)
|
|
flush_hash_page(batch->vpn[i], batch->pte[i],
|
|
batch->psize, batch->ssize, local);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* low_hash_fault is called when we the low level hash code failed
|
|
* to instert a PTE due to an hypervisor error
|
|
*/
|
|
void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc)
|
|
{
|
|
enum ctx_state prev_state = exception_enter();
|
|
|
|
if (user_mode(regs)) {
|
|
#ifdef CONFIG_PPC_SUBPAGE_PROT
|
|
if (rc == -2)
|
|
_exception(SIGSEGV, regs, SEGV_ACCERR, address);
|
|
else
|
|
#endif
|
|
_exception(SIGBUS, regs, BUS_ADRERR, address);
|
|
} else
|
|
bad_page_fault(regs, address, SIGBUS);
|
|
|
|
exception_exit(prev_state);
|
|
}
|
|
|
|
long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
|
|
unsigned long pa, unsigned long rflags,
|
|
unsigned long vflags, int psize, int ssize)
|
|
{
|
|
unsigned long hpte_group;
|
|
long slot;
|
|
|
|
repeat:
|
|
hpte_group = ((hash & htab_hash_mask) *
|
|
HPTES_PER_GROUP) & ~0x7UL;
|
|
|
|
/* Insert into the hash table, primary slot */
|
|
slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, vflags,
|
|
psize, psize, ssize);
|
|
|
|
/* Primary is full, try the secondary */
|
|
if (unlikely(slot == -1)) {
|
|
hpte_group = ((~hash & htab_hash_mask) *
|
|
HPTES_PER_GROUP) & ~0x7UL;
|
|
slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags,
|
|
vflags | HPTE_V_SECONDARY,
|
|
psize, psize, ssize);
|
|
if (slot == -1) {
|
|
if (mftb() & 0x1)
|
|
hpte_group = ((hash & htab_hash_mask) *
|
|
HPTES_PER_GROUP)&~0x7UL;
|
|
|
|
mmu_hash_ops.hpte_remove(hpte_group);
|
|
goto repeat;
|
|
}
|
|
}
|
|
|
|
return slot;
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC
|
|
static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
|
|
{
|
|
unsigned long hash;
|
|
unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
|
|
unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
|
|
unsigned long mode = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL));
|
|
long ret;
|
|
|
|
hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
|
|
|
|
/* Don't create HPTE entries for bad address */
|
|
if (!vsid)
|
|
return;
|
|
|
|
ret = hpte_insert_repeating(hash, vpn, __pa(vaddr), mode,
|
|
HPTE_V_BOLTED,
|
|
mmu_linear_psize, mmu_kernel_ssize);
|
|
|
|
BUG_ON (ret < 0);
|
|
spin_lock(&linear_map_hash_lock);
|
|
BUG_ON(linear_map_hash_slots[lmi] & 0x80);
|
|
linear_map_hash_slots[lmi] = ret | 0x80;
|
|
spin_unlock(&linear_map_hash_lock);
|
|
}
|
|
|
|
static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
|
|
{
|
|
unsigned long hash, hidx, slot;
|
|
unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
|
|
unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
|
|
|
|
hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
|
|
spin_lock(&linear_map_hash_lock);
|
|
BUG_ON(!(linear_map_hash_slots[lmi] & 0x80));
|
|
hidx = linear_map_hash_slots[lmi] & 0x7f;
|
|
linear_map_hash_slots[lmi] = 0;
|
|
spin_unlock(&linear_map_hash_lock);
|
|
if (hidx & _PTEIDX_SECONDARY)
|
|
hash = ~hash;
|
|
slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
|
|
slot += hidx & _PTEIDX_GROUP_IX;
|
|
mmu_hash_ops.hpte_invalidate(slot, vpn, mmu_linear_psize,
|
|
mmu_linear_psize,
|
|
mmu_kernel_ssize, 0);
|
|
}
|
|
|
|
void __kernel_map_pages(struct page *page, int numpages, int enable)
|
|
{
|
|
unsigned long flags, vaddr, lmi;
|
|
int i;
|
|
|
|
local_irq_save(flags);
|
|
for (i = 0; i < numpages; i++, page++) {
|
|
vaddr = (unsigned long)page_address(page);
|
|
lmi = __pa(vaddr) >> PAGE_SHIFT;
|
|
if (lmi >= linear_map_hash_count)
|
|
continue;
|
|
if (enable)
|
|
kernel_map_linear_page(vaddr, lmi);
|
|
else
|
|
kernel_unmap_linear_page(vaddr, lmi);
|
|
}
|
|
local_irq_restore(flags);
|
|
}
|
|
#endif /* CONFIG_DEBUG_PAGEALLOC */
|
|
|
|
void hash__setup_initial_memory_limit(phys_addr_t first_memblock_base,
|
|
phys_addr_t first_memblock_size)
|
|
{
|
|
/* We don't currently support the first MEMBLOCK not mapping 0
|
|
* physical on those processors
|
|
*/
|
|
BUG_ON(first_memblock_base != 0);
|
|
|
|
/* On LPAR systems, the first entry is our RMA region,
|
|
* non-LPAR 64-bit hash MMU systems don't have a limitation
|
|
* on real mode access, but using the first entry works well
|
|
* enough. We also clamp it to 1G to avoid some funky things
|
|
* such as RTAS bugs etc...
|
|
*/
|
|
ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
|
|
|
|
/* Finally limit subsequent allocations */
|
|
memblock_set_current_limit(ppc64_rma_size);
|
|
}
|