diff options
Diffstat (limited to 'arch/x86_64/kernel/relocate_kernel.S')
| -rw-r--r-- | arch/x86_64/kernel/relocate_kernel.S | 171 |
1 files changed, 152 insertions, 19 deletions
diff --git a/arch/x86_64/kernel/relocate_kernel.S b/arch/x86_64/kernel/relocate_kernel.S index d24fa9b72a2..14e95872c6a 100644 --- a/arch/x86_64/kernel/relocate_kernel.S +++ b/arch/x86_64/kernel/relocate_kernel.S @@ -7,31 +7,169 @@ */ #include <linux/linkage.h> +#include <asm/page.h> +#include <asm/kexec.h> - /* - * Must be relocatable PIC code callable as a C function, that once - * it starts can not use the previous processes stack. - */ - .globl relocate_new_kernel +/* + * Must be relocatable PIC code callable as a C function + */ + +#define PTR(x) (x << 3) +#define PAGE_ALIGNED (1 << PAGE_SHIFT) +#define PAGE_ATTR 0x63 /* _PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED|_PAGE_DIRTY */ + + .text + .align PAGE_ALIGNED .code64 + .globl relocate_kernel +relocate_kernel: + /* %rdi indirection_page + * %rsi page_list + * %rdx start address + */ + + /* map the control page at its virtual address */ + + movq $0x0000ff8000000000, %r10 /* mask */ + mov $(39 - 3), %cl /* bits to shift */ + movq PTR(VA_CONTROL_PAGE)(%rsi), %r11 /* address to map */ + + movq %r11, %r9 + andq %r10, %r9 + shrq %cl, %r9 + + movq PTR(VA_PGD)(%rsi), %r8 + addq %r8, %r9 + movq PTR(PA_PUD_0)(%rsi), %r8 + orq $PAGE_ATTR, %r8 + movq %r8, (%r9) + + shrq $9, %r10 + sub $9, %cl + + movq %r11, %r9 + andq %r10, %r9 + shrq %cl, %r9 + + movq PTR(VA_PUD_0)(%rsi), %r8 + addq %r8, %r9 + movq PTR(PA_PMD_0)(%rsi), %r8 + orq $PAGE_ATTR, %r8 + movq %r8, (%r9) + + shrq $9, %r10 + sub $9, %cl + + movq %r11, %r9 + andq %r10, %r9 + shrq %cl, %r9 + + movq PTR(VA_PMD_0)(%rsi), %r8 + addq %r8, %r9 + movq PTR(PA_PTE_0)(%rsi), %r8 + orq $PAGE_ATTR, %r8 + movq %r8, (%r9) + + shrq $9, %r10 + sub $9, %cl + + movq %r11, %r9 + andq %r10, %r9 + shrq %cl, %r9 + + movq PTR(VA_PTE_0)(%rsi), %r8 + addq %r8, %r9 + movq PTR(PA_CONTROL_PAGE)(%rsi), %r8 + orq $PAGE_ATTR, %r8 + movq %r8, (%r9) + + /* identity map the control page at its physical address */ + + movq $0x0000ff8000000000, %r10 /* mask */ + mov $(39 - 3), %cl /* bits to shift */ + movq PTR(PA_CONTROL_PAGE)(%rsi), %r11 /* address to map */ + + movq %r11, %r9 + andq %r10, %r9 + shrq %cl, %r9 + + movq PTR(VA_PGD)(%rsi), %r8 + addq %r8, %r9 + movq PTR(PA_PUD_1)(%rsi), %r8 + orq $PAGE_ATTR, %r8 + movq %r8, (%r9) + + shrq $9, %r10 + sub $9, %cl + + movq %r11, %r9 + andq %r10, %r9 + shrq %cl, %r9 + + movq PTR(VA_PUD_1)(%rsi), %r8 + addq %r8, %r9 + movq PTR(PA_PMD_1)(%rsi), %r8 + orq $PAGE_ATTR, %r8 + movq %r8, (%r9) + + shrq $9, %r10 + sub $9, %cl + + movq %r11, %r9 + andq %r10, %r9 + shrq %cl, %r9 + + movq PTR(VA_PMD_1)(%rsi), %r8 + addq %r8, %r9 + movq PTR(PA_PTE_1)(%rsi), %r8 + orq $PAGE_ATTR, %r8 + movq %r8, (%r9) + + shrq $9, %r10 + sub $9, %cl + + movq %r11, %r9 + andq %r10, %r9 + shrq %cl, %r9 + + movq PTR(VA_PTE_1)(%rsi), %r8 + addq %r8, %r9 + movq PTR(PA_CONTROL_PAGE)(%rsi), %r8 + orq $PAGE_ATTR, %r8 + movq %r8, (%r9) + relocate_new_kernel: - /* %rdi page_list - * %rsi reboot_code_buffer + /* %rdi indirection_page + * %rsi page_list * %rdx start address - * %rcx page_table - * %r8 arg5 - * %r9 arg6 */ /* zero out flags, and disable interrupts */ pushq $0 popfq - /* set a new stack at the bottom of our page... */ - lea 4096(%rsi), %rsp + /* get physical address of control page now */ + /* this is impossible after page table switch */ + movq PTR(PA_CONTROL_PAGE)(%rsi), %r8 + + /* get physical address of page table now too */ + movq PTR(PA_TABLE_PAGE)(%rsi), %rcx - /* store the parameters back on the stack */ - pushq %rdx /* store the start address */ + /* switch to new set of page tables */ + movq PTR(PA_PGD)(%rsi), %r9 + movq %r9, %cr3 + + /* setup a new stack at the end of the physical control page */ + lea 4096(%r8), %rsp + + /* jump to identity mapped page */ + addq $(identity_mapped - relocate_kernel), %r8 + pushq %r8 + ret + +identity_mapped: + /* store the start address on the stack */ + pushq %rdx /* Set cr0 to a known state: * 31 1 == Paging enabled @@ -136,8 +274,3 @@ relocate_new_kernel: xorq %r15, %r15 ret -relocate_new_kernel_end: - - .globl relocate_new_kernel_size -relocate_new_kernel_size: - .quad relocate_new_kernel_end - relocate_new_kernel |