| Message ID | 20220412173407.13637-5-varad.gautam@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | SMP Support for x86 UEFI Tests | expand |
On Tue, Apr 12, 2022, Varad Gautam wrote: > diff --git a/lib/x86/setup.c b/lib/x86/setup.c > index 94e9f86..7dd6677 100644 > --- a/lib/x86/setup.c > +++ b/lib/x86/setup.c > @@ -170,7 +170,7 @@ void setup_multiboot(struct mbi_bootinfo *bi) > #ifdef CONFIG_EFI > > /* From x86/efi/efistart64.S */ > -extern void load_gdt_tss(size_t tss_offset); > +extern void setup_segments64(void); > > static efi_status_t setup_memory_allocator(efi_bootinfo_t *efi_bootinfo) > { > @@ -275,6 +275,8 @@ static void setup_gdt_tss(void) > /* 64-bit setup_tss does not use the stacktop argument. */ > tss_offset = setup_tss(NULL); > load_gdt_tss(tss_offset); > + > + setup_segments64(); Rather than call back into asm, how about doing this in inline asm? It's a bit gross no matter what, but this has the advantage of getting to use KERNEL_CS/DS without extra magic. And then the future patch that manipulates MSR_GS_BASE can use the wrmsr() helper. asm volatile("mov %0, %%ds\n\t" "mov %0, %%es\n\t" "mov %0, %%fs\n\t" "mov %0, %%gs\n\t" "mov %0, %%ss\n\t" "pushq %1\n\t" "lea 1f(%%rip), %0\n\t" "pushq %0\n\t" "lretq\n\t" "1:" :: "r" ((u64)KERNEL_DS), "i" (KERNEL_CS) ); > efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo) > diff --git a/x86/efi/efistart64.S b/x86/efi/efistart64.S > index ea3d1c0..8eadca5 100644 > --- a/x86/efi/efistart64.S > +++ b/x86/efi/efistart64.S > @@ -26,15 +26,8 @@ ptl4: > .code64 > .text > > -.globl load_gdt_tss > -load_gdt_tss: > - /* Load GDT */ > - lgdt gdt_descr(%rip) > - > - /* Load TSS */ > - mov %rdi, %rax > - ltr %ax > - > +.globl setup_segments64 > +setup_segments64: > /* Update data segments */ > mov $0x10, %ax /* 3rd entry in gdt64: 32/64-bit data segment */ > mov %ax, %ds > -- > 2.32.0 >
diff --git a/lib/x86/desc.c b/lib/x86/desc.c index 049adeb..3b1208b 100644 --- a/lib/x86/desc.c +++ b/lib/x86/desc.c @@ -362,6 +362,12 @@ void set_gdt_entry(int sel, unsigned long base, u32 limit, u8 type, u8 flags) #endif } +void load_gdt_tss(size_t tss_offset) +{ + lgdt(&gdt_descr); + ltr(tss_offset); +} + #ifndef __x86_64__ void set_gdt_task_gate(u16 sel, u16 tss_sel) { diff --git a/lib/x86/desc.h b/lib/x86/desc.h index ae0928f..83a16dd 100644 --- a/lib/x86/desc.h +++ b/lib/x86/desc.h @@ -222,6 +222,7 @@ void set_idt_entry(int vec, void *addr, int dpl); void set_idt_sel(int vec, u16 sel); void set_idt_dpl(int vec, u16 dpl); void set_gdt_entry(int sel, unsigned long base, u32 limit, u8 access, u8 gran); +void load_gdt_tss(size_t tss_offset); void set_intr_alt_stack(int e, void *fn); void print_current_tss_info(void); handler handle_exception(u8 v, handler fn); diff --git a/lib/x86/setup.c b/lib/x86/setup.c index 94e9f86..7dd6677 100644 --- a/lib/x86/setup.c +++ b/lib/x86/setup.c @@ -170,7 +170,7 @@ void setup_multiboot(struct mbi_bootinfo *bi) #ifdef CONFIG_EFI /* From x86/efi/efistart64.S */ -extern void load_gdt_tss(size_t tss_offset); +extern void setup_segments64(void); static efi_status_t setup_memory_allocator(efi_bootinfo_t *efi_bootinfo) { @@ -275,6 +275,8 @@ static void setup_gdt_tss(void) /* 64-bit setup_tss does not use the stacktop argument. */ tss_offset = setup_tss(NULL); load_gdt_tss(tss_offset); + + setup_segments64(); } efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo) diff --git a/x86/efi/efistart64.S b/x86/efi/efistart64.S index ea3d1c0..8eadca5 100644 --- a/x86/efi/efistart64.S +++ b/x86/efi/efistart64.S @@ -26,15 +26,8 @@ ptl4: .code64 .text -.globl load_gdt_tss -load_gdt_tss: - /* Load GDT */ - lgdt gdt_descr(%rip) - - /* Load TSS */ - mov %rdi, %rax - ltr %ax - +.globl setup_segments64 +setup_segments64: /* Update data segments */ mov $0x10, %ax /* 3rd entry in gdt64: 32/64-bit data segment */ mov %ax, %ds
Split load_gdt_tss() functionality into: 1. Load gdt/tss 2. Setup segments in 64-bit mode and update %cs via far-return and move load_gdt_tss() to desc.c to share this code between EFI and non-EFI tests. Signed-off-by: Varad Gautam <varad.gautam@suse.com> --- lib/x86/desc.c | 6 ++++++ lib/x86/desc.h | 1 + lib/x86/setup.c | 4 +++- x86/efi/efistart64.S | 11 ++--------- 4 files changed, 12 insertions(+), 10 deletions(-)