[PATCH 3/3 -v4] kexec/i386: setup kexec page table in C
Huang Ying
ying.huang at intel.com
Thu Oct 30 21:48:15 EDT 2008
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 at intel.com>
---
arch/x86/include/asm/kexec.h | 17 -----
arch/x86/kernel/machine_kexec_32.c | 59 ++++++++++++++----
arch/x86/kernel/relocate_kernel_32.S | 114 -----------------------------------
3 files changed, 49 insertions(+), 141 deletions(-)
--- a/arch/x86/kernel/machine_kexec_32.c
+++ b/arch/x86/kernel/machine_kexec_32.c
@@ -99,6 +99,45 @@ static int machine_kexec_alloc_page_tabl
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 @@ static int machine_kexec_alloc_page_tabl
*
* - 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 @@ void machine_kexec(struct kimage *image)
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)
--- a/arch/x86/kernel/relocate_kernel_32.S
+++ b/arch/x86/kernel/relocate_kernel_32.S
@@ -10,15 +10,12 @@
#include <asm/page.h>
#include <asm/kexec.h>
#include <asm/processor-flags.h>
-#include <asm/pgtable.h>
/*
* Must be relocatable PIC code callable as a C function
*/
#define PTR(x) (x << 2)
-#define PAGE_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
-#define PAE_PGD_ATTR (_PAGE_PRESENT)
/* control_page + KEXEC_CONTROL_CODE_MAX_SIZE
* ~ control_page + PAGE_SIZE are used as data storage and stack for
@@ -59,117 +56,6 @@ relocate_kernel:
movl %cr4, %eax
movl %eax, CR4(%edi)
-#ifdef CONFIG_X86_PAE
- /* map the control page at its virtual address */
-
- movl PTR(VA_PGD)(%ebp), %edi
- movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
- andl $0xc0000000, %eax
- shrl $27, %eax
- addl %edi, %eax
-
- movl PTR(PA_PMD_0)(%ebp), %edx
- orl $PAE_PGD_ATTR, %edx
- movl %edx, (%eax)
-
- movl PTR(VA_PMD_0)(%ebp), %edi
- movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
- andl $0x3fe00000, %eax
- shrl $18, %eax
- addl %edi, %eax
-
- movl PTR(PA_PTE_0)(%ebp), %edx
- orl $PAGE_ATTR, %edx
- movl %edx, (%eax)
-
- movl PTR(VA_PTE_0)(%ebp), %edi
- movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
- andl $0x001ff000, %eax
- shrl $9, %eax
- addl %edi, %eax
-
- movl PTR(PA_CONTROL_PAGE)(%ebp), %edx
- orl $PAGE_ATTR, %edx
- movl %edx, (%eax)
-
- /* identity map the control page at its physical address */
-
- movl PTR(VA_PGD)(%ebp), %edi
- movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
- andl $0xc0000000, %eax
- shrl $27, %eax
- addl %edi, %eax
-
- movl PTR(PA_PMD_1)(%ebp), %edx
- orl $PAE_PGD_ATTR, %edx
- movl %edx, (%eax)
-
- movl PTR(VA_PMD_1)(%ebp), %edi
- movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
- andl $0x3fe00000, %eax
- shrl $18, %eax
- addl %edi, %eax
-
- movl PTR(PA_PTE_1)(%ebp), %edx
- orl $PAGE_ATTR, %edx
- movl %edx, (%eax)
-
- movl PTR(VA_PTE_1)(%ebp), %edi
- movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
- andl $0x001ff000, %eax
- shrl $9, %eax
- addl %edi, %eax
-
- movl PTR(PA_CONTROL_PAGE)(%ebp), %edx
- orl $PAGE_ATTR, %edx
- movl %edx, (%eax)
-#else
- /* map the control page at its virtual address */
-
- movl PTR(VA_PGD)(%ebp), %edi
- movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
- andl $0xffc00000, %eax
- shrl $20, %eax
- addl %edi, %eax
-
- movl PTR(PA_PTE_0)(%ebp), %edx
- orl $PAGE_ATTR, %edx
- movl %edx, (%eax)
-
- movl PTR(VA_PTE_0)(%ebp), %edi
- movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
- andl $0x003ff000, %eax
- shrl $10, %eax
- addl %edi, %eax
-
- movl PTR(PA_CONTROL_PAGE)(%ebp), %edx
- orl $PAGE_ATTR, %edx
- movl %edx, (%eax)
-
- /* identity map the control page at its physical address */
-
- movl PTR(VA_PGD)(%ebp), %edi
- movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
- andl $0xffc00000, %eax
- shrl $20, %eax
- addl %edi, %eax
-
- movl PTR(PA_PTE_1)(%ebp), %edx
- orl $PAGE_ATTR, %edx
- movl %edx, (%eax)
-
- movl PTR(VA_PTE_1)(%ebp), %edi
- movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
- andl $0x003ff000, %eax
- shrl $10, %eax
- addl %edi, %eax
-
- movl PTR(PA_CONTROL_PAGE)(%ebp), %edx
- orl $PAGE_ATTR, %edx
- movl %edx, (%eax)
-#endif
-
-relocate_new_kernel:
/* read the arguments and say goodbye to the stack */
movl 20+4(%esp), %ebx /* page_list */
movl 20+8(%esp), %ebp /* list of pages */
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -5,21 +5,8 @@
# define PA_CONTROL_PAGE 0
# define VA_CONTROL_PAGE 1
# define PA_PGD 2
-# define VA_PGD 3
-# define PA_PTE_0 4
-# define VA_PTE_0 5
-# define PA_PTE_1 6
-# define VA_PTE_1 7
-# define PA_SWAP_PAGE 8
-# ifdef CONFIG_X86_PAE
-# define PA_PMD_0 9
-# define VA_PMD_0 10
-# define PA_PMD_1 11
-# define VA_PMD_1 12
-# define PAGES_NR 13
-# else
-# define PAGES_NR 9
-# endif
+# define PA_SWAP_PAGE 3
+# define PAGES_NR 4
#else
# define PA_CONTROL_PAGE 0
# define VA_CONTROL_PAGE 1
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