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[PATCH] x86_64 machine_kexec: Use standard pagetable helpers
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Use the standard hardware page table manipulation macros.
This is possible now that linux works with all 4 levels
of the page tables.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Eric W. Biederman authored and Linus Torvalds committed Jul 29, 2005
1 parent 36c4fd2 commit 8bf2755
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Showing 2 changed files with 27 additions and 42 deletions.
67 changes: 25 additions & 42 deletions arch/x86_64/kernel/machine_kexec.c
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Original file line number Diff line number Diff line change
Expand Up @@ -8,105 +8,88 @@

#include <linux/mm.h>
#include <linux/kexec.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/reboot.h>
#include <asm/pda.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
#include <asm/io.h>
#include <asm/apic.h>
#include <asm/cpufeature.h>
#include <asm/hw_irq.h>

#define LEVEL0_SIZE (1UL << 12UL)
#define LEVEL1_SIZE (1UL << 21UL)
#define LEVEL2_SIZE (1UL << 30UL)
#define LEVEL3_SIZE (1UL << 39UL)
#define LEVEL4_SIZE (1UL << 48UL)

#define L0_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
#define L1_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_PSE)
#define L2_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
#define L3_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)

static void init_level2_page(u64 *level2p, unsigned long addr)

static void init_level2_page(pmd_t *level2p, unsigned long addr)
{
unsigned long end_addr;

addr &= PAGE_MASK;
end_addr = addr + LEVEL2_SIZE;
end_addr = addr + PUD_SIZE;
while (addr < end_addr) {
*(level2p++) = addr | L1_ATTR;
addr += LEVEL1_SIZE;
set_pmd(level2p++, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
addr += PMD_SIZE;
}
}

static int init_level3_page(struct kimage *image, u64 *level3p,
static int init_level3_page(struct kimage *image, pud_t *level3p,
unsigned long addr, unsigned long last_addr)
{
unsigned long end_addr;
int result;

result = 0;
addr &= PAGE_MASK;
end_addr = addr + LEVEL3_SIZE;
end_addr = addr + PGDIR_SIZE;
while ((addr < last_addr) && (addr < end_addr)) {
struct page *page;
u64 *level2p;
pmd_t *level2p;

page = kimage_alloc_control_pages(image, 0);
if (!page) {
result = -ENOMEM;
goto out;
}
level2p = (u64 *)page_address(page);
level2p = (pmd_t *)page_address(page);
init_level2_page(level2p, addr);
*(level3p++) = __pa(level2p) | L2_ATTR;
addr += LEVEL2_SIZE;
set_pud(level3p++, __pud(__pa(level2p) | _KERNPG_TABLE));
addr += PUD_SIZE;
}
/* clear the unused entries */
while (addr < end_addr) {
*(level3p++) = 0;
addr += LEVEL2_SIZE;
pud_clear(level3p++);
addr += PUD_SIZE;
}
out:
return result;
}


static int init_level4_page(struct kimage *image, u64 *level4p,
static int init_level4_page(struct kimage *image, pgd_t *level4p,
unsigned long addr, unsigned long last_addr)
{
unsigned long end_addr;
int result;

result = 0;
addr &= PAGE_MASK;
end_addr = addr + LEVEL4_SIZE;
end_addr = addr + (PTRS_PER_PGD * PGDIR_SIZE);
while ((addr < last_addr) && (addr < end_addr)) {
struct page *page;
u64 *level3p;
pud_t *level3p;

page = kimage_alloc_control_pages(image, 0);
if (!page) {
result = -ENOMEM;
goto out;
}
level3p = (u64 *)page_address(page);
level3p = (pud_t *)page_address(page);
result = init_level3_page(image, level3p, addr, last_addr);
if (result) {
goto out;
}
*(level4p++) = __pa(level3p) | L3_ATTR;
addr += LEVEL3_SIZE;
set_pgd(level4p++, __pgd(__pa(level3p) | _KERNPG_TABLE));
addr += PGDIR_SIZE;
}
/* clear the unused entries */
while (addr < end_addr) {
*(level4p++) = 0;
addr += LEVEL3_SIZE;
pgd_clear(level4p++);
addr += PGDIR_SIZE;
}
out:
return result;
Expand All @@ -115,8 +98,8 @@ static int init_level4_page(struct kimage *image, u64 *level4p,

static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
{
u64 *level4p;
level4p = (u64 *)__va(start_pgtable);
pgd_t *level4p;
level4p = (pgd_t *)__va(start_pgtable);
return init_level4_page(image, level4p, 0, end_pfn << PAGE_SHIFT);
}

Expand Down Expand Up @@ -176,7 +159,7 @@ int machine_kexec_prepare(struct kimage *image)

/* Calculate the offsets */
start_pgtable = page_to_pfn(image->control_code_page) << PAGE_SHIFT;
control_code_buffer = start_pgtable + 4096UL;
control_code_buffer = start_pgtable + PAGE_SIZE;

/* Setup the identity mapped 64bit page table */
result = init_pgtable(image, start_pgtable);
Expand Down Expand Up @@ -212,7 +195,7 @@ NORET_TYPE void machine_kexec(struct kimage *image)
/* Calculate the offsets */
page_list = image->head;
start_pgtable = page_to_pfn(image->control_code_page) << PAGE_SHIFT;
control_code_buffer = start_pgtable + 4096UL;
control_code_buffer = start_pgtable + PAGE_SIZE;

/* Set the low half of the page table to my identity mapped
* page table for kexec. Leave the high half pointing at the
Expand Down
2 changes: 2 additions & 0 deletions include/asm-x86_64/pgtable.h
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Original file line number Diff line number Diff line change
Expand Up @@ -176,6 +176,8 @@ extern inline void pgd_clear (pgd_t * pgd)
(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_PCD)
#define __PAGE_KERNEL_LARGE \
(__PAGE_KERNEL | _PAGE_PSE)
#define __PAGE_KERNEL_LARGE_EXEC \
(__PAGE_KERNEL_EXEC | _PAGE_PSE)

#define MAKE_GLOBAL(x) __pgprot((x) | _PAGE_GLOBAL)

Expand Down

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