kexec/i386: setup kexec page table in C
Impact: change the kexec bootstrap code implementation from assembly to C
This patch transforms the kexec page tables setup code from assembler
code to C code in machine_kexec_prepare. This improves readability and
reduces code line number.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c
index 1100312..37f4200 100644
--- a/arch/x86/kernel/machine_kexec_32.c
+++ b/arch/x86/kernel/machine_kexec_32.c
@@ -99,6 +99,45 @@
return 0;
}
+static void machine_kexec_page_table_set_one(
+ pgd_t *pgd, pmd_t *pmd, pte_t *pte,
+ unsigned long vaddr, unsigned long paddr)
+{
+ pud_t *pud;
+
+ pgd += pgd_index(vaddr);
+#ifdef CONFIG_X86_PAE
+ if (!(pgd_val(*pgd) & _PAGE_PRESENT))
+ set_pgd(pgd, __pgd(__pa(pmd) | _PAGE_PRESENT));
+#endif
+ pud = pud_offset(pgd, vaddr);
+ pmd = pmd_offset(pud, vaddr);
+ if (!(pmd_val(*pmd) & _PAGE_PRESENT))
+ set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
+ pte = pte_offset_kernel(pmd, vaddr);
+ set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC));
+}
+
+static void machine_kexec_prepare_page_tables(struct kimage *image)
+{
+ void *control_page;
+ pmd_t *pmd = 0;
+
+ control_page = page_address(image->control_code_page);
+#ifdef CONFIG_X86_PAE
+ pmd = image->arch.pmd0;
+#endif
+ machine_kexec_page_table_set_one(
+ image->arch.pgd, pmd, image->arch.pte0,
+ (unsigned long)control_page, __pa(control_page));
+#ifdef CONFIG_X86_PAE
+ pmd = image->arch.pmd1;
+#endif
+ machine_kexec_page_table_set_one(
+ image->arch.pgd, pmd, image->arch.pte1,
+ __pa(control_page), __pa(control_page));
+}
+
/*
* A architecture hook called to validate the
* proposed image and prepare the control pages
@@ -112,12 +151,19 @@
*
* - Make control page executable.
* - Allocate page tables
+ * - Setup page tables
*/
int machine_kexec_prepare(struct kimage *image)
{
+ int error;
+
if (nx_enabled)
set_pages_x(image->control_code_page, 1);
- return machine_kexec_alloc_page_tables(image);
+ error = machine_kexec_alloc_page_tables(image);
+ if (error)
+ return error;
+ machine_kexec_prepare_page_tables(image);
+ return 0;
}
/*
@@ -176,17 +222,6 @@
page_list[PA_CONTROL_PAGE] = __pa(control_page);
page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;
page_list[PA_PGD] = __pa(image->arch.pgd);
- page_list[VA_PGD] = (unsigned long)image->arch.pgd;
-#ifdef CONFIG_X86_PAE
- page_list[PA_PMD_0] = __pa(image->arch.pmd0);
- page_list[VA_PMD_0] = (unsigned long)image->arch.pmd0;
- page_list[PA_PMD_1] = __pa(image->arch.pmd1);
- page_list[VA_PMD_1] = (unsigned long)image->arch.pmd1;
-#endif
- page_list[PA_PTE_0] = __pa(image->arch.pte0);
- page_list[VA_PTE_0] = (unsigned long)image->arch.pte0;
- page_list[PA_PTE_1] = __pa(image->arch.pte1);
- page_list[VA_PTE_1] = (unsigned long)image->arch.pte1;
if (image->type == KEXEC_TYPE_DEFAULT)
page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page)
