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Date: Thu, 13 Dec 2012 14:02:10 -0800
From: Yinghai Lu <yinghai@...nel.org>
To: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...e.hu>,
"H. Peter Anvin" <hpa@...or.com>
Cc: "Eric W. Biederman" <ebiederm@...ssion.com>,
Andrew Morton <akpm@...ux-foundation.org>,
linux-kernel@...r.kernel.org, Yinghai Lu <yinghai@...nel.org>
Subject: [PATCH v6 16/27] x86, kexec: Merge 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.
init_level4_page does not check existing pgd/pud.
We will need to use ident_mapping_init with pfn_mapped array to
map ram only, and two entries in pfn_mapped could be in same pgd/pud,
so we need to check if pgd/pud is present instead of init_level4_page.
So merge these two set functions to make new ident_mapping_init not
check pgd/pud for every pmd in same pgd/pud, and use it to replace
init_level4_page.
Signed-off-by: Yinghai Lu <yinghai@...nel.org>
---
arch/x86/kernel/machine_kexec_64.c | 214 ++++++++++++++----------------------
1 file changed, 80 insertions(+), 134 deletions(-)
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index be14ee1..a0bf7fb 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -21,139 +21,6 @@
#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);
@@ -203,6 +70,84 @@ err:
return result;
}
+static void ident_pmd_init(pmd_t *pmd_page,
+ unsigned long addr, unsigned long end)
+{
+ addr &= PMD_MASK;
+ for (; addr < end; addr += PMD_SIZE) {
+ pmd_t *pmd = pmd_page + pmd_index(addr);
+
+ if (!pmd_present(*pmd))
+ set_pmd(pmd, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
+ }
+}
+static int ident_pud_init(struct kimage *image, pud_t *pud_page,
+ unsigned long addr, unsigned long end)
+{
+ unsigned long next;
+ struct page *page;
+
+ for (; addr < end; addr = next) {
+ pud_t *pud = pud_page + pud_index(addr);
+ pmd_t *pmd;
+
+ next = (addr & PUD_MASK) + PUD_SIZE;
+ if (next > end)
+ next = end;
+
+ if (pud_present(*pud)) {
+ pmd = pmd_offset(pud, 0);
+ ident_pmd_init(pmd, addr, next);
+ continue;
+ }
+ page = kimage_alloc_control_pages(image, 0);
+ if (!page)
+ return -ENOMEM;
+ pmd = (pmd_t *)page_address(page);
+ clear_page(pmd);
+ ident_pmd_init(pmd, addr, next);
+ set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
+ }
+
+ return 0;
+}
+static int ident_mapping_init(struct kimage *image, pgd_t *pgd_page,
+ unsigned long addr, unsigned long end)
+{
+ unsigned long next;
+ struct page *page;
+ int result;
+
+ for (; addr < end; addr = next) {
+ pgd_t *pgd = pgd_page + pgd_index(addr);
+ pud_t *pud;
+
+ next = (addr & PGDIR_MASK) + PGDIR_SIZE;
+ if (next > end)
+ next = end;
+
+ if (pgd_present(*pgd)) {
+ pud = pud_offset(pgd, 0);
+ result = ident_pud_init(image, pud, addr, next);
+ if (result)
+ return result;
+ continue;
+ }
+
+ page = kimage_alloc_control_pages(image, 0);
+ if (!page)
+ return -ENOMEM;
+ pud = (pud_t *)page_address(page);
+ clear_page(pud);
+ result = ident_pud_init(image, pud, addr, next);
+ if (result)
+ return result;
+ set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
+ }
+
+ return 0;
+}
+
static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
{
unsigned long mstart, mend;
@@ -211,7 +156,8 @@ static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
int i;
level4p = (pgd_t *)__va(start_pgtable);
- result = init_level4_page(image, level4p, 0, max_pfn << PAGE_SHIFT);
+ clear_page(level4p);
+ result = ident_mapping_init(image, level4p, 0, max_pfn << PAGE_SHIFT);
if (result)
return result;
--
1.7.10.4
--
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