diff options
| author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2023-09-24 17:33:48 +0200 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2023-09-24 17:33:48 +0200 |
| commit | bf1cd17a446cb99668d4398473e15b5613086ff5 (patch) | |
| tree | f9e90549776abe2391aa142bc14539f566cc5d49 /i386/i386 | |
| parent | 1c053811c13f3bec4793dfb3ff0cc47854efa448 (diff) | |
SMP: Fix setting up initial gdt
We cannot access cpu_id_lut from the initial AP state, so update the
percpu segment after loading gdt.
Diffstat (limited to 'i386/i386')
| -rw-r--r-- | i386/i386/cpuboot.S | 49 | ||||
| -rw-r--r-- | i386/i386/mp_desc.c | 2 |
2 files changed, 28 insertions, 23 deletions
diff --git a/i386/i386/cpuboot.S b/i386/i386/cpuboot.S index 356633e5..c85c4ddb 100644 --- a/i386/i386/cpuboot.S +++ b/i386/i386/cpuboot.S @@ -39,20 +39,22 @@ apboot_idt_ptr: .align 16 .word 0 apboot_gdt_descr: - .word 13*8+7 + .word 14*8-1 .long apboot_gdt - KERNELBASE .align 16 apboot_gdt: - /* NULL segment */ + /* NULL segment = 0x0 */ .quad 0 - /* KERNEL_CS */ + + /* KERNEL_CS = 0x8 */ .word 0xffff /* Segment limit first 0-15 bits*/ .word (-KERNELBASE) & 0xffff /*Base first 0-15 bits*/ .byte ((-KERNELBASE) >> 16) & 0xff /*Base 16-23 bits */ .byte ACC_PL_K | ACC_CODE_R | ACC_P /*Access byte */ .byte ((SZ_32 | SZ_G) << 4) | 0xf /* High 4 bits */ .byte ((-KERNELBASE) >> 24) & 0xff /*Base 24-31 bits */ - /* KERNEL_DS */ + + /* KERNEL_DS = 0x10 */ .word 0xffff /*Segment limit */ .word (-KERNELBASE) & 0xffff /*Base first 0-15 bits*/ .byte ((-KERNELBASE) >> 16) & 0xff @@ -80,6 +82,7 @@ apboot_gdt: /* USER_GDT = 0x48 and 0x50 */ .quad 0 + .quad 0 /* USER_TSS64 = 0x58 */ .quad 0 @@ -128,6 +131,21 @@ _apboot: movw %ax, %es movw %ax, %ss + lgdtl apboot_gdt_descr - KERNELBASE + ljmpl $KERNEL_CS, $1f +1: + xorl %eax, %eax + movw %ax, %ds + movw %ax, %es + movw %ax, %fs + movw %ax, %gs + movw $KERNEL_DS, %ax + movw %ax, %ds + movw %ax, %es + movw %ax, %fs + movw %ax, %gs + movw %ax, %ss + /* Get CPU number */ movl $1, %eax cpuid @@ -141,28 +159,15 @@ _apboot: addl $percpu_array - KERNELBASE, %eax /* Record our cpu number */ - movl %ecx, PERCPU_CPU_ID(%eax) + movl %ecx, (PERCPU_CPU_ID + KERNELBASE)(%eax) /* Set up temporary percpu descriptor */ - movw %ax, apboot_percpu_low - KERNELBASE + movw %ax, apboot_percpu_low shr $16, %eax - movb %al, apboot_percpu_med - KERNELBASE + movb %al, apboot_percpu_med shr $8, %ax - movb %al, apboot_percpu_high - KERNELBASE + movb %al, apboot_percpu_high - lgdtl apboot_gdt_descr - KERNELBASE - ljmpl $KERNEL_CS, $1f -1: - xorl %eax, %eax - movw %ax, %ds - movw %ax, %es - movw %ax, %fs - movw %ax, %gs - movw $KERNEL_DS, %ax - movw %ax, %ds - movw %ax, %es - movw %ax, %fs - movw %ax, %ss movw $PERCPU_DS, %ax movw %ax, %gs @@ -200,7 +205,7 @@ _apboot: .align 16 .word 0 gdt_descr_tmp: - .short 3*8+7 + .short 3*8-1 .long M(gdt_tmp) .align 16 diff --git a/i386/i386/mp_desc.c b/i386/i386/mp_desc.c index f4ccc381..467f2728 100644 --- a/i386/i386/mp_desc.c +++ b/i386/i386/mp_desc.c @@ -276,7 +276,7 @@ cpu_setup(int cpu) void cpu_ap_main() { - int cpu = cpu_number_slow(); + int cpu = cpu_number(); do { cpu_pause(); |