UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

RISC-V: Fixmap support and MM cleanups 

This patchset does:
1. Moves MM related code from kernel/setup.c to mm/init.c
2. Implements compile-time fixed mappings

Using fixed mappings, we get earlyprints even without SBI calls.

For example, we can now use kernel parameter
"earlycon=uart8250,mmio,0x10000000"
to get early prints on QEMU virt machine without using SBI calls.

The patchset is tested on QEMU virt machine.

Palmer: It looks like some of the code movement here conflicted with the
patches to move hartid handling around.  As far as I can tell the only
changed code was in smp_setup_processor_id(), and I've kept the one in
smp.c.
This commit is contained in:
Palmer Dabbelt 2019-03-04 11:41:36 -08:00
parent f7ccc35aa3 823900cd01
commit 13fd5de065
No known key found for this signature in database
GPG Key ID: EF4CA1502CCBAB41
6 changed files with 208 additions and 128 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/riscv/Kconfig
View File

@ -89,6 +89,9 @@ config GENERIC_CSUM
config GENERIC_HWEIGHT
def_bool y
config FIX_EARLYCON_MEM
def_bool y
config PGTABLE_LEVELS
int
default 3 if 64BIT

44
arch/riscv/include/asm/fixmap.h Normal file
View File

@ -0,0 +1,44 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2019 Western Digital Corporation or its affiliates.
*/
#ifndef _ASM_RISCV_FIXMAP_H
#define _ASM_RISCV_FIXMAP_H
#include <linux/kernel.h>
#include <linux/sizes.h>
#include <asm/page.h>
#include <asm/pgtable.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.
*
* These 'compile-time allocated' memory buffers are page-sized. Use
* set_fixmap(idx,phys) to associate physical memory with fixmap indices.
*/
enum fixed_addresses {
FIX_HOLE,
FIX_EARLYCON_MEM_BASE,
__end_of_fixed_addresses
};
#define FIXADDR_SIZE (__end_of_fixed_addresses * PAGE_SIZE)
#define FIXADDR_TOP (PAGE_OFFSET)
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
#define FIXMAP_PAGE_IO PAGE_KERNEL
#define __early_set_fixmap __set_fixmap
#define __late_set_fixmap __set_fixmap
#define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR)
extern void __set_fixmap(enum fixed_addresses idx,
phys_addr_t phys, pgprot_t prot);
#include <asm-generic/fixmap.h>
#endif /* _ASM_RISCV_FIXMAP_H */

1
arch/riscv/include/asm/pgtable.h
View File

@ -404,6 +404,7 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
#define kern_addr_valid(addr) (1) /* FIXME */
#endif
extern void setup_bootmem(void);
extern void paging_init(void);
static inline void pgtable_cache_init(void)

130
arch/riscv/kernel/setup.c
View File

@ -23,7 +23,6 @@
#include <linux/mm.h>
#include <linux/memblock.h>
#include <linux/sched.h>
#include <linux/initrd.h>
#include <linux/console.h>
#include <linux/screen_info.h>
#include <linux/of_fdt.h>
@ -61,83 +60,6 @@ EXPORT_SYMBOL(empty_zero_page);
atomic_t hart_lottery;
unsigned long boot_cpu_hartid;
#ifdef CONFIG_BLK_DEV_INITRD
static void __init setup_initrd(void)
{
unsigned long size;
if (initrd_start >= initrd_end) {
pr_info("initrd not found or empty");
goto disable;
}
if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
pr_err("initrd extends beyond end of memory");
goto disable;
}
size = initrd_end - initrd_start;
memblock_reserve(__pa(initrd_start), size);
initrd_below_start_ok = 1;
pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
(void *)(initrd_start), size);
return;
disable:
pr_cont(" - disabling initrd\n");
initrd_start = 0;
initrd_end = 0;
}
#endif /* CONFIG_BLK_DEV_INITRD */
pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
#ifndef __PAGETABLE_PMD_FOLDED
#define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
#endif
asmlinkage void __init setup_vm(void)
{
extern char _start;
uintptr_t i;
uintptr_t pa = (uintptr_t) &_start;
pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
va_pa_offset = PAGE_OFFSET - pa;
pfn_base = PFN_DOWN(pa);
/* Sanity check alignment and size */
BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
#ifndef __PAGETABLE_PMD_FOLDED
trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
__pgprot(_PAGE_TABLE));
trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
swapper_pg_dir[o] =
pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
__pgprot(_PAGE_TABLE));
}
for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
#else
trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
pfn_pgd(PFN_DOWN(pa), prot);
for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
swapper_pg_dir[o] =
pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
}
#endif
}
void __init parse_dtb(unsigned int hartid, void *dtb)
{
if (early_init_dt_scan(__va(dtb)))
@ -150,60 +72,17 @@ void __init parse_dtb(unsigned int hartid, void *dtb)
#endif
}
static void __init setup_bootmem(void)
{
struct memblock_region *reg;
phys_addr_t mem_size = 0;
/* Find the memory region containing the kernel */
for_each_memblock(memory, reg) {
phys_addr_t vmlinux_end = __pa(_end);
phys_addr_t end = reg->base + reg->size;
if (reg->base <= vmlinux_end && vmlinux_end <= end) {
/*
* Reserve from the start of the region to the end of
* the kernel
*/
memblock_reserve(reg->base, vmlinux_end - reg->base);
mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
}
}
BUG_ON(mem_size == 0);
set_max_mapnr(PFN_DOWN(mem_size));
max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
#ifdef CONFIG_BLK_DEV_INITRD
setup_initrd();
#endif /* CONFIG_BLK_DEV_INITRD */
early_init_fdt_reserve_self();
early_init_fdt_scan_reserved_mem();
memblock_allow_resize();
memblock_dump_all();
for_each_memblock(memory, reg) {
unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
memblock_set_node(PFN_PHYS(start_pfn),
PFN_PHYS(end_pfn - start_pfn),
&memblock.memory, 0);
}
}
void __init setup_arch(char **cmdline_p)
{
*cmdline_p = boot_command_line;
parse_early_param();
init_mm.start_code = (unsigned long) _stext;
init_mm.end_code = (unsigned long) _etext;
init_mm.end_data = (unsigned long) _edata;
init_mm.brk = (unsigned long) _end;
*cmdline_p = boot_command_line;
parse_early_param();
setup_bootmem();
paging_init();
unflatten_device_tree();
@ -222,4 +101,3 @@ void __init setup_arch(char **cmdline_p)
riscv_fill_hwcap();
}

2
arch/riscv/kernel/smp.c
View File

@ -42,7 +42,7 @@ unsigned long __cpuid_to_hartid_map[NR_CPUS] = {
void __init smp_setup_processor_id(void)
{
cpuid_to_hartid_map(0) = boot_cpu_hartid;
cpuid_to_hartid_map(0) = boot_cpu_hartid;
}
/* A collection of single bit ipi messages. */

156
arch/riscv/mm/init.c
View File

@ -17,7 +17,9 @@
#include <linux/initrd.h>
#include <linux/swap.h>
#include <linux/sizes.h>
#include <linux/of_fdt.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
@ -66,7 +68,159 @@ void free_initmem(void)
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
static void __init setup_initrd(void)
{
unsigned long size;
if (initrd_start >= initrd_end) {
pr_info("initrd not found or empty");
goto disable;
}
if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
pr_err("initrd extends beyond end of memory");
goto disable;
}
size = initrd_end - initrd_start;
memblock_reserve(__pa(initrd_start), size);
initrd_below_start_ok = 1;
pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
(void *)(initrd_start), size);
return;
disable:
pr_cont(" - disabling initrd\n");
initrd_start = 0;
initrd_end = 0;
}
void __init free_initrd_mem(unsigned long start, unsigned long end)
{
free_reserved_area((void *)start, (void *)end, -1, "initrd");
}
#endif /* CONFIG_BLK_DEV_INITRD */
void __init setup_bootmem(void)
{
struct memblock_region *reg;
phys_addr_t mem_size = 0;
/* Find the memory region containing the kernel */
for_each_memblock(memory, reg) {
phys_addr_t vmlinux_end = __pa(_end);
phys_addr_t end = reg->base + reg->size;
if (reg->base <= vmlinux_end && vmlinux_end <= end) {
/*
* Reserve from the start of the region to the end of
* the kernel
*/
memblock_reserve(reg->base, vmlinux_end - reg->base);
mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
}
}
BUG_ON(mem_size == 0);
set_max_mapnr(PFN_DOWN(mem_size));
max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
#ifdef CONFIG_BLK_DEV_INITRD
setup_initrd();
#endif /* CONFIG_BLK_DEV_INITRD */
early_init_fdt_reserve_self();
early_init_fdt_scan_reserved_mem();
memblock_allow_resize();
memblock_dump_all();
for_each_memblock(memory, reg) {
unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
memblock_set_node(PFN_PHYS(start_pfn),
PFN_PHYS(end_pfn - start_pfn),
&memblock.memory, 0);
}
}
pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
#ifndef __PAGETABLE_PMD_FOLDED
#define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
#endif
pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
{
unsigned long addr = __fix_to_virt(idx);
pte_t *ptep;
BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
ptep = &fixmap_pte[pte_index(addr)];
if (pgprot_val(prot)) {
set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
} else {
pte_clear(&init_mm, addr, ptep);
local_flush_tlb_page(addr);
}
}
asmlinkage void __init setup_vm(void)
{
extern char _start;
uintptr_t i;
uintptr_t pa = (uintptr_t) &_start;
pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
va_pa_offset = PAGE_OFFSET - pa;
pfn_base = PFN_DOWN(pa);
/* Sanity check alignment and size */
BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
#ifndef __PAGETABLE_PMD_FOLDED
trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
__pgprot(_PAGE_TABLE));
trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
swapper_pg_dir[o] =
pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
__pgprot(_PAGE_TABLE));
}
for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pmd),
__pgprot(_PAGE_TABLE));
fixmap_pmd[(FIXADDR_START >> PMD_SHIFT) % PTRS_PER_PMD] =
pfn_pmd(PFN_DOWN((uintptr_t)fixmap_pte),
__pgprot(_PAGE_TABLE));
#else
trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
pfn_pgd(PFN_DOWN(pa), prot);
for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
swapper_pg_dir[o] =
pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
}
swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pte),
__pgprot(_PAGE_TABLE));
#endif
}