Commit 8bf27556 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Linus Torvalds
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[PATCH] x86_64 machine_kexec: Use standard pagetable helpers 



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: default avatarEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 36c4fd23

arch/x86_64/kernel/machine_kexec.c

+25 −42
Original line number Diff line number Diff line
@@ -8,43 +8,26 @@ 


#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;
@@ -52,32 +35,32 @@ static int init_level3_page(struct kimage *image, u64 *level3p, 


	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;
@@ -85,28 +68,28 @@ static int init_level4_page(struct kimage *image, u64 *level4p, 


	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;
@@ -115,8 +98,8 @@ out: 


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);

}
@@ -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);
@@ -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

include/asm-x86_64/pgtable.h

+2 −0
Original line number Diff line number Diff line
@@ -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)

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