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@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-24-git-send-email-yinghai@kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index be14ee1..d2d7e02 100644 (file)
--- 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;