x86_64: move kernel

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 276 insertions, 0 deletions

diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
new file mode 100644
index 000000000000..14e95872c6a3
--- /dev/null
+++ b/arch/x86/kernel/relocate_kernel_64.S
@@ -0,0 +1,276 @@
+/*
+ * relocate_kernel.S - put the kernel image in place to boot
+ * Copyright (C) 2002-2005 Eric Biederman  <ebiederm@xmission.com>
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#include <linux/linkage.h>
+#include <asm/page.h>
+#include <asm/kexec.h>
+
+/*
+ * 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 indirection_page
+         * %rsi page_list
+         * %rdx start address
+         */
+
+        /* zero out flags, and disable interrupts */
+        pushq $0
+        popfq
+
+        /* 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
+
+        /* 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
+         * 18 0 == Alignment check disabled
+         * 16 0 == Write protect disabled
+         * 3  0 == No task switch
+         * 2  0 == Don't do FP software emulation.
+         * 0  1 == Proctected mode enabled
+         */
+        movq    %cr0, %rax
+        andq    $~((1<<18)|(1<<16)|(1<<3)|(1<<2)), %rax
+        orl     $((1<<31)|(1<<0)), %eax
+        movq    %rax, %cr0
+
+        /* Set cr4 to a known state:
+         * 10 0 == xmm exceptions disabled
+         * 9  0 == xmm registers instructions disabled
+         * 8  0 == performance monitoring counter disabled
+         * 7  0 == page global disabled
+         * 6  0 == machine check exceptions disabled
+         * 5  1 == physical address extension enabled
+         * 4  0 == page size extensions disabled
+         * 3  0 == Debug extensions disabled
+         * 2  0 == Time stamp disable (disabled)
+         * 1  0 == Protected mode virtual interrupts disabled
+         * 0  0 == VME disabled
+         */
+
+        movq    $((1<<5)), %rax
+        movq    %rax, %cr4
+
+        jmp 1f
+1:
+
+        /* Switch to the identity mapped page tables,
+         * and flush the TLB.
+        */
+        movq    %rcx, %cr3
+
+        /* Do the copies */
+        movq    %rdi, %rcx      /* Put the page_list in %rcx */
+        xorq    %rdi, %rdi
+        xorq    %rsi, %rsi
+        jmp     1f
+
+0:      /* top, read another word for the indirection page */
+
+        movq    (%rbx), %rcx
+        addq    $8,     %rbx
+1:
+        testq   $0x1,   %rcx  /* is it a destination page? */
+        jz      2f
+        movq    %rcx,   %rdi
+        andq    $0xfffffffffffff000, %rdi
+        jmp     0b
+2:
+        testq   $0x2,   %rcx  /* is it an indirection page? */
+        jz      2f
+        movq    %rcx,   %rbx
+        andq    $0xfffffffffffff000, %rbx
+        jmp     0b
+2:
+        testq   $0x4,   %rcx  /* is it the done indicator? */
+        jz      2f
+        jmp     3f
+2:
+        testq   $0x8,   %rcx  /* is it the source indicator? */
+        jz      0b            /* Ignore it otherwise */
+        movq    %rcx,   %rsi  /* For ever source page do a copy */
+        andq    $0xfffffffffffff000, %rsi
+
+        movq    $512,   %rcx
+        rep ; movsq
+        jmp     0b
+3:
+
+        /* To be certain of avoiding problems with self-modifying code
+         * I need to execute a serializing instruction here.
+         * So I flush the TLB by reloading %cr3 here, it's handy,
+         * and not processor dependent.
+         */
+        movq    %cr3, %rax
+        movq    %rax, %cr3
+
+        /* set all of the registers to known values */
+        /* leave %rsp alone */
+
+        xorq    %rax, %rax
+        xorq    %rbx, %rbx
+        xorq    %rcx, %rcx
+        xorq    %rdx, %rdx
+        xorq    %rsi, %rsi
+        xorq    %rdi, %rdi
+        xorq    %rbp, %rbp
+        xorq    %r8,  %r8
+        xorq    %r9,  %r9
+        xorq    %r10, %r9
+        xorq    %r11, %r11
+        xorq    %r12, %r12
+        xorq    %r13, %r13
+        xorq    %r14, %r14
+        xorq    %r15, %r15
+
+        ret