Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee13...

[pandora-kernel.git] / arch / x86_64 / kernel / relocate_kernel.S

diff --git a/arch/x86_64/kernel/relocate_kernel.S b/arch/x86_64/kernel/relocate_kernel.S
index d24fa9b..14e9587 100644 (file)
--- 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