Re: [PATCH 4/4] Add cpu_number and cpuboot

[Samuel Thibault]

See my previous review on this, you haven't addressed by comments.

Damien Zammit, le sam. 21 janv. 2023 08:05:06 +0000, a ecrit:
> ---
>  i386/i386/cpu_number.c |  37 ++++++++++
>  i386/i386/cpuboot.S    | 164 +++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 201 insertions(+)
>  create mode 100644 i386/i386/cpu_number.c
>  create mode 100644 i386/i386/cpuboot.S
> 
> diff --git a/i386/i386/cpu_number.c b/i386/i386/cpu_number.c
> new file mode 100644
> index 00000000..d4621669
> --- /dev/null
> +++ b/i386/i386/cpu_number.c
> @@ -0,0 +1,37 @@
> +/*
> + * Copyright (c) 2022 Free Software Foundation, Inc.
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <i386/cpu_number.h>
> +#include <i386/apic.h>
> +#include <i386/smp.h>
> +#include <i386/cpu.h>
> +
> +#if NCPUS > 1
> +int cpu_number(void)
> +{
> +     int kernel_id;
> +     unsigned long flags;
> +
> +     cpu_intr_save(&flags);
> +
> +     kernel_id = apic_get_cpu_kernel_id(apic_get_current_cpu());
> +
> +     cpu_intr_restore(flags);
> +
> +     return kernel_id;
> +}
> +#endif
> diff --git a/i386/i386/cpuboot.S b/i386/i386/cpuboot.S
> new file mode 100644
> index 00000000..4a5823be
> --- /dev/null
> +++ b/i386/i386/cpuboot.S
> @@ -0,0 +1,164 @@
> +/*
> + * Copyright (c) 2022 Free Software Foundation, Inc.
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <mach/machine/asm.h>
> +#include <i386/i386asm.h>
> +#include <i386/proc_reg.h>
> +#include <i386/apic.h>
> +#include <i386/cpu_number.h>
> +#include <i386/seg.h>
> +
> +#define AP_BOOT_ADDR 0x7000
> +#define M(addr)              (addr - apboot + AP_BOOT_ADDR)
> +#define CR0_CLEAR_FLAGS_CACHE_ENABLE (CR0_CD | CR0_NW)
> +#define CR0_SET_FLAGS        (CR0_CLEAR_FLAGS_CACHE_ENABLE | CR0_PE)
> +#define CR0_CLEAR_FLAGS (CR0_PG | CR0_AM | CR0_WP | CR0_NE | CR0_TS | CR0_EM 
> | CR0_MP)
> +#define BOOT_CS              0x8
> +#define BOOT_DS              0x10
> +
> +.text
> +
> +.align 16
> +apboot_idt_ptr:
> +     .long 0
> +.align 16
> +     .word 0
> +apboot_gdt_descr:
> +     .word 3*8+7
> +     .long apboot_gdt - KERNELBASE
> +.align 16
> +apboot_gdt:
> +     /* NULL segment */
> +     .quad 0
> +     /* KERNEL_CS */
> +     .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_P | ACC_CODE_R) /*Access byte */
> +     .byte 0xcf /* High 4 bits */
> +     .byte ((-KERNELBASE) >> 24) & 0xff /*Base 24-31 bits */
> +     /* KERNEL_DS */
> +     .word 0xffff /*Segment limit */
> +     .word (-KERNELBASE) & 0xffff /*Base first 0-15 bits*/
> +     .byte ((-KERNELBASE) >> 16) & 0xff
> +     .byte (ACC_P | ACC_DATA_W) /*Access byte*/
> +     .byte 0xcf /* High 4 bits */
> +     .byte ((-KERNELBASE) >> 24) & 0xff /*Base 24-31 bits */
> +
> +.globl apboot, apbootend
> +.align 16
> +.code16
> +
> +apboot:
> +_apboot:
> +     cli
> +     xorl    %eax, %eax
> +     movl    %eax, %cr3
> +     mov     %ax, %ds
> +     mov     %ax, %es
> +     mov     %ax, %fs
> +     mov     %ax, %gs
> +     mov     %ax, %ss
> +
> +     lgdt    M(gdt_descr_tmp)
> +
> +     movl    %cr0, %eax
> +     andl    $~CR0_CLEAR_FLAGS, %eax
> +     orl     $CR0_SET_FLAGS, %eax
> +     movl    %eax, %cr0
> +
> +     ljmp    $BOOT_CS, $M(0f)
> +0:
> +     .code32
> +     movw    $BOOT_DS, %ax
> +     movw    %ax, %ds
> +     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
> +
> +     /* Load null Interrupt descriptor table */
> +     mov     apboot_idt_ptr, %ebx
> +     lidt    (%ebx)
> +
> +     /* Enable local apic */
> +     xorl    %eax, %eax
> +     xorl    %edx, %edx
> +     movl    $APIC_MSR, %ecx
> +     rdmsr
> +     orl     $APIC_MSR_ENABLE, %eax
> +     andl    $(~APIC_MSR_BSP), %eax
> +     movl    $APIC_MSR, %ecx
> +     wrmsr
> +
> +     /* Load int_stack_top[cpu] -> esp */
> +     CPU_NUMBER(%edx)
> +     movl    CX(EXT(int_stack_top), %edx), %esp
> +
> +     /* Ensure stack alignment */
> +     andl    $0xfffffff0, %esp
> +
> +     /* Reset EFLAGS to a known state */
> +     pushl $0
> +     popfl
> +
> +     /* Finish the cpu configuration */
> +     call EXT(cpu_ap_main)
> +
> +     /* NOT REACHED */
> +     hlt
> +
> +.align 16
> +    .word 0
> +gdt_descr_tmp:
> +    .short 3*8+7
> +    .long M(gdt_tmp)
> +
> +.align 16
> +gdt_tmp:
> +    /* 0 */
> +    .quad 0
> +    /* BOOT_CS */
> +    .word 0xffff
> +    .word 0x0000
> +    .byte 0x00
> +    .byte (ACC_P | ACC_CODE_R)
> +    .byte 0xcf
> +    .byte 0x00
> +    /* BOOT_DS */
> +    .word 0xffff
> +    .word 0x0000
> +    .byte 0x00
> +    .byte (ACC_P | ACC_DATA_W)
> +    .byte 0xcf
> +    .byte 0x00
> +
> +_apbootend:
> +apbootend:
> --
> 2.34.1
> 
> 
> 

-- 
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.