x86/efi: Runtime services virtual mapping

[linux-2.6-block.git] / arch / x86 / platform / efi / efi_stub_64.S

diff --git a/arch/x86/platform/efi/efi_stub_64.S b/arch/x86/platform/efi/efi_stub_64.S
index 4c07ccab8146f0bbed2850f586a68f126b2bc7eb..88073b1402988b49eb6c5e95f9f801a14d40f144 100644 (file)
--- a/arch/x86/platform/efi/efi_stub_64.S
+++ b/arch/x86/platform/efi/efi_stub_64.S
@@ -34,10 +34,47 @@
        mov %rsi, %cr0;                 \
        mov (%rsp), %rsp
 
+       /* stolen from gcc */
+       .macro FLUSH_TLB_ALL
+       movq %r15, efi_scratch(%rip)
+       movq %r14, efi_scratch+8(%rip)
+       movq %cr4, %r15
+       movq %r15, %r14
+       andb $0x7f, %r14b
+       movq %r14, %cr4
+       movq %r15, %cr4
+       movq efi_scratch+8(%rip), %r14
+       movq efi_scratch(%rip), %r15
+       .endm
+
+       .macro SWITCH_PGT
+       cmpb $0, efi_scratch+24(%rip)
+       je 1f
+       movq %r15, efi_scratch(%rip)            # r15
+       # save previous CR3
+       movq %cr3, %r15
+       movq %r15, efi_scratch+8(%rip)          # prev_cr3
+       movq efi_scratch+16(%rip), %r15         # EFI pgt
+       movq %r15, %cr3
+       1:
+       .endm
+
+       .macro RESTORE_PGT
+       cmpb $0, efi_scratch+24(%rip)
+       je 2f
+       movq efi_scratch+8(%rip), %r15
+       movq %r15, %cr3
+       movq efi_scratch(%rip), %r15
+       FLUSH_TLB_ALL
+       2:
+       .endm
+
 ENTRY(efi_call0)
        SAVE_XMM
        subq $32, %rsp
+       SWITCH_PGT
        call *%rdi
+       RESTORE_PGT
        addq $32, %rsp
        RESTORE_XMM
        ret
@@ -47,7 +84,9 @@ ENTRY(efi_call1)
        SAVE_XMM
        subq $32, %rsp
        mov  %rsi, %rcx
+       SWITCH_PGT
        call *%rdi
+       RESTORE_PGT
        addq $32, %rsp
        RESTORE_XMM
        ret
@@ -57,7 +96,9 @@ ENTRY(efi_call2)
        SAVE_XMM
        subq $32, %rsp
        mov  %rsi, %rcx
+       SWITCH_PGT
        call *%rdi
+       RESTORE_PGT
        addq $32, %rsp
        RESTORE_XMM
        ret
@@ -68,7 +109,9 @@ ENTRY(efi_call3)
        subq $32, %rsp
        mov  %rcx, %r8
        mov  %rsi, %rcx
+       SWITCH_PGT
        call *%rdi
+       RESTORE_PGT
        addq $32, %rsp
        RESTORE_XMM
        ret
@@ -80,7 +123,9 @@ ENTRY(efi_call4)
        mov %r8, %r9
        mov %rcx, %r8
        mov %rsi, %rcx
+       SWITCH_PGT
        call *%rdi
+       RESTORE_PGT
        addq $32, %rsp
        RESTORE_XMM
        ret
@@ -93,7 +138,9 @@ ENTRY(efi_call5)
        mov %r8, %r9
        mov %rcx, %r8
        mov %rsi, %rcx
+       SWITCH_PGT
        call *%rdi
+       RESTORE_PGT
        addq $48, %rsp
        RESTORE_XMM
        ret
@@ -109,8 +156,15 @@ ENTRY(efi_call6)
        mov %r8, %r9
        mov %rcx, %r8
        mov %rsi, %rcx
+       SWITCH_PGT
        call *%rdi
+       RESTORE_PGT
        addq $48, %rsp
        RESTORE_XMM
        ret
 ENDPROC(efi_call6)
+
+       .data
+ENTRY(efi_scratch)
+       .fill 3,8,0
+       .byte 0