diff options
Diffstat (limited to 'arch/x86/platform/efi/efi_stub_64.S')
| -rw-r--r-- | arch/x86/platform/efi/efi_stub_64.S | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/arch/x86/platform/efi/efi_stub_64.S b/arch/x86/platform/efi/efi_stub_64.S new file mode 100644 index 00000000000..5fcda727255 --- /dev/null +++ b/arch/x86/platform/efi/efi_stub_64.S @@ -0,0 +1,259 @@ +/* + * 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 |