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|
/*
* Function calling ABI conversion from Linux to EFI for x86_64
*
* Copyright (C) 2007 Intel Corp
* Bibo Mao <bibo.mao@intel.com>
* Huang Ying <ying.huang@intel.com>
*/
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/msr.h>
#include <asm/processor-flags.h>
#include <asm/page_types.h>
#define SAVE_XMM \
mov %rsp, %rax; \
subq $0x70, %rsp; \
and $~0xf, %rsp; \
mov %rax, (%rsp); \
mov %cr0, %rax; \
clts; \
mov %rax, 0x8(%rsp); \
movaps %xmm0, 0x60(%rsp); \
movaps %xmm1, 0x50(%rsp); \
movaps %xmm2, 0x40(%rsp); \
movaps %xmm3, 0x30(%rsp); \
movaps %xmm4, 0x20(%rsp); \
movaps %xmm5, 0x10(%rsp)
#define RESTORE_XMM \
movaps 0x60(%rsp), %xmm0; \
movaps 0x50(%rsp), %xmm1; \
movaps 0x40(%rsp), %xmm2; \
movaps 0x30(%rsp), %xmm3; \
movaps 0x20(%rsp), %xmm4; \
movaps 0x10(%rsp), %xmm5; \
mov 0x8(%rsp), %rsi; \
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_call)
SAVE_XMM
mov (%rsp), %rax
mov 8(%rax), %rax
subq $48, %rsp
mov %r9, 32(%rsp)
mov %rax, 40(%rsp)
mov %r8, %r9
mov %rcx, %r8
mov %rsi, %rcx
SWITCH_PGT
call *%rdi
RESTORE_PGT
addq $48, %rsp
RESTORE_XMM
ret
ENDPROC(efi_call)
#ifdef CONFIG_EFI_MIXED
/*
* We run this function from the 1:1 mapping.
*
* This function must be invoked with a 1:1 mapped stack.
*/
ENTRY(__efi64_thunk)
movl %ds, %eax
push %rax
movl %es, %eax
push %rax
movl %ss, %eax
push %rax
subq $32, %rsp
movl %esi, 0x0(%rsp)
movl %edx, 0x4(%rsp)
movl %ecx, 0x8(%rsp)
movq %r8, %rsi
movl %esi, 0xc(%rsp)
movq %r9, %rsi
movl %esi, 0x10(%rsp)
sgdt save_gdt(%rip)
leaq 1f(%rip), %rbx
movq %rbx, func_rt_ptr(%rip)
/* Switch to gdt with 32-bit segments */
movl 64(%rsp), %eax
lgdt (%rax)
leaq efi_enter32(%rip), %rax
pushq $__KERNEL_CS
pushq %rax
lretq
1: addq $32, %rsp
lgdt save_gdt(%rip)
pop %rbx
movl %ebx, %ss
pop %rbx
movl %ebx, %es
pop %rbx
movl %ebx, %ds
/*
* Convert 32-bit status code into 64-bit.
*/
test %rax, %rax
jz 1f
movl %eax, %ecx
andl $0x0fffffff, %ecx
andl $0xf0000000, %eax
shl $32, %rax
or %rcx, %rax
1:
ret
ENDPROC(__efi64_thunk)
ENTRY(efi_exit32)
movq func_rt_ptr(%rip), %rax
push %rax
mov %rdi, %rax
ret
ENDPROC(efi_exit32)
.code32
/*
* EFI service pointer must be in %edi.
*
* The stack should represent the 32-bit calling convention.
*/
ENTRY(efi_enter32)
movl $__KERNEL_DS, %eax
movl %eax, %ds
movl %eax, %es
movl %eax, %ss
/* Reload pgtables */
movl %cr3, %eax
movl %eax, %cr3
/* Disable paging */
movl %cr0, %eax
btrl $X86_CR0_PG_BIT, %eax
movl %eax, %cr0
/* Disable long mode via EFER */
movl $MSR_EFER, %ecx
rdmsr
btrl $_EFER_LME, %eax
wrmsr
call *%edi
/* We must preserve return value */
movl %eax, %edi
/*
* Some firmware will return with interrupts enabled. Be sure to
* disable them before we switch GDTs.
*/
cli
movl 68(%esp), %eax
movl %eax, 2(%eax)
lgdtl (%eax)
movl %cr4, %eax
btsl $(X86_CR4_PAE_BIT), %eax
movl %eax, %cr4
movl %cr3, %eax
movl %eax, %cr3
movl $MSR_EFER, %ecx
rdmsr
btsl $_EFER_LME, %eax
wrmsr
xorl %eax, %eax
lldt %ax
movl 72(%esp), %eax
pushl $__KERNEL_CS
pushl %eax
/* Enable paging */
movl %cr0, %eax
btsl $X86_CR0_PG_BIT, %eax
movl %eax, %cr0
lret
ENDPROC(efi_enter32)
.data
.balign 8
.global efi32_boot_gdt
efi32_boot_gdt: .word 0
.quad 0
save_gdt: .word 0
.quad 0
func_rt_ptr: .quad 0
.global efi_gdt64
efi_gdt64:
.word efi_gdt64_end - efi_gdt64
.long 0 /* Filled out by user */
.word 0
.quad 0x0000000000000000 /* NULL descriptor */
.quad 0x00af9a000000ffff /* __KERNEL_CS */
.quad 0x00cf92000000ffff /* __KERNEL_DS */
.quad 0x0080890000000000 /* TS descriptor */
.quad 0x0000000000000000 /* TS continued */
efi_gdt64_end:
#endif /* CONFIG_EFI_MIXED */
.data
ENTRY(efi_scratch)
.fill 3,8,0
.byte 0
.quad 0
|
