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>

1 files changed, 26 insertions, 135 deletions

diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index be14ee120c43..d2d7e023a8c8 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;