[tip:x86/mm2] x86, kexec: Replace ident_mapping_init and init_level4_page

From: tip-bot for Yinghai Lu
Date: Tue Jan 29 2013 - 20:43:37 EST


Commit-ID: 9ebdc79f7a177d3098b89ba8ef2dd2b235163685
Gitweb: http://git.kernel.org/tip/9ebdc79f7a177d3098b89ba8ef2dd2b235163685
Author: Yinghai Lu <yinghai@xxxxxxxxxx>
AuthorDate: Thu, 24 Jan 2013 12:20:04 -0800
Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Tue, 29 Jan 2013 15:26:29 -0800

x86, kexec: Replace ident_mapping_init and init_level4_page

Now ident_mapping_init is checking if pgd/pud is present for every 2M,
so several 2Ms are in same PUD, it will keep checking if pud is there
with same pud.

init_level4_page just does not check existing pgd/pud.

We could use generic mapping_init with different settings in info to
replace those two local grown version functions.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1359058816-7615-24-git-send-email-yinghai@xxxxxxxxxx
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/machine_kexec_64.c | 161 ++++++-------------------------------
1 file changed, 26 insertions(+), 135 deletions(-)

diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index be14ee1..d2d7e02 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -16,144 +16,12 @@
#include <linux/io.h>
#include <linux/suspend.h>

+#include <asm/init.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
#include <asm/debugreg.h>

-static int init_one_level2_page(struct kimage *image, pgd_t *pgd,
- unsigned long addr)
-{
- pud_t *pud;
- pmd_t *pmd;
- struct page *page;
- int result = -ENOMEM;
-
- addr &= PMD_MASK;
- pgd += pgd_index(addr);
- if (!pgd_present(*pgd)) {
- page = kimage_alloc_control_pages(image, 0);
- if (!page)
- goto out;
- pud = (pud_t *)page_address(page);
- clear_page(pud);
- set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
- }
- pud = pud_offset(pgd, addr);
- if (!pud_present(*pud)) {
- page = kimage_alloc_control_pages(image, 0);
- if (!page)
- goto out;
- pmd = (pmd_t *)page_address(page);
- clear_page(pmd);
- set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
- }
- pmd = pmd_offset(pud, addr);
- if (!pmd_present(*pmd))
- set_pmd(pmd, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
- result = 0;
-out:
- return result;
-}
-
-static int ident_mapping_init(struct kimage *image, pgd_t *level4p,
- unsigned long mstart, unsigned long mend)
-{
- int result;
-
- mstart = round_down(mstart, PMD_SIZE);
- mend = round_up(mend - 1, PMD_SIZE);
-
- while (mstart < mend) {
- result = init_one_level2_page(image, level4p, mstart);
- if (result)
- return result;
-
- mstart += PMD_SIZE;
- }
-
- return 0;
-}
-
-static void init_level2_page(pmd_t *level2p, unsigned long addr)
-{
- unsigned long end_addr;
-
- addr &= PAGE_MASK;
- end_addr = addr + PUD_SIZE;
- while (addr < end_addr) {
- set_pmd(level2p++, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
- addr += PMD_SIZE;
- }
-}
-
-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 + PGDIR_SIZE;
- while ((addr < last_addr) && (addr < end_addr)) {
- struct page *page;
- pmd_t *level2p;
-
- page = kimage_alloc_control_pages(image, 0);
- if (!page) {
- result = -ENOMEM;
- goto out;
- }
- level2p = (pmd_t *)page_address(page);
- init_level2_page(level2p, addr);
- set_pud(level3p++, __pud(__pa(level2p) | _KERNPG_TABLE));
- addr += PUD_SIZE;
- }
- /* clear the unused entries */
- while (addr < end_addr) {
- pud_clear(level3p++);
- addr += PUD_SIZE;
- }
-out:
- return result;
-}
-
-
-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 + (PTRS_PER_PGD * PGDIR_SIZE);
- while ((addr < last_addr) && (addr < end_addr)) {
- struct page *page;
- pud_t *level3p;
-
- page = kimage_alloc_control_pages(image, 0);
- if (!page) {
- result = -ENOMEM;
- goto out;
- }
- level3p = (pud_t *)page_address(page);
- result = init_level3_page(image, level3p, addr, last_addr);
- if (result)
- goto out;
- set_pgd(level4p++, __pgd(__pa(level3p) | _KERNPG_TABLE));
- addr += PGDIR_SIZE;
- }
- /* clear the unused entries */
- while (addr < end_addr) {
- pgd_clear(level4p++);
- addr += PGDIR_SIZE;
- }
-out:
- return result;
-}
-
static void free_transition_pgtable(struct kimage *image)
{
free_page((unsigned long)image->arch.pud);
@@ -203,15 +71,37 @@ err:
return result;
}

+static void *alloc_pgt_page(void *data)
+{
+ struct kimage *image = (struct kimage *)data;
+ struct page *page;
+ void *p = NULL;
+
+ page = kimage_alloc_control_pages(image, 0);
+ if (page) {
+ p = page_address(page);
+ clear_page(p);
+ }
+
+ return p;
+}
+
static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
{
+ struct x86_mapping_info info = {
+ .alloc_pgt_page = alloc_pgt_page,
+ .context = image,
+ .pmd_flag = __PAGE_KERNEL_LARGE_EXEC,
+ };
unsigned long mstart, mend;
pgd_t *level4p;
int result;
int i;

level4p = (pgd_t *)__va(start_pgtable);
- result = init_level4_page(image, level4p, 0, max_pfn << PAGE_SHIFT);
+ clear_page(level4p);
+ result = kernel_ident_mapping_init(&info, level4p,
+ 0, max_pfn << PAGE_SHIFT);
if (result)
return result;

@@ -225,7 +115,8 @@ static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
mstart = image->segment[i].mem;
mend = mstart + image->segment[i].memsz;

- result = ident_mapping_init(image, level4p, mstart, mend);
+ result = kernel_ident_mapping_init(&info,
+ level4p, mstart, mend);

if (result)
return result;
--
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