Re: [PATCH v3 03/17] hw/loongarch: Add slave cpu boot_code

[gaosong]

在 2023/12/27 下午4:52, Philippe Mathieu-Daudé 写道:
> Hi,
>
> On 27/12/23 09:08, Song Gao wrote:
> > Signed-off-by: Song Gao <gaosong@loongson.cn>
> > ---
> >   hw/loongarch/boot.c | 71 ++++++++++++++++++++++++++++++++++++++++++++-
> >   1 file changed, 70 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/loongarch/boot.c b/hw/loongarch/boot.c
> > index 3075c276d4..faff880153 100644
> > --- a/hw/loongarch/boot.c
> > +++ b/hw/loongarch/boot.c
> > @@ -14,6 +14,54 @@
> >   #include "qemu/error-report.h"
> >   #include "sysemu/reset.h"
> >   +static unsigned int slave_boot_code[] = {
>
> 'const'
Got it.
> > +                  /* Configure reset ebase.         */
> > +    0x0400302c,   /* csrwr      $r12,0xc            */
> > +
> > +                  /* Disable interrupt.             */
> > +    0x0380100c,   /* ori        $r12,$r0,0x4        */
> > +    0x04000180,   /* csrxchg    $r0,$r12,0x0        */
> > +
> > +                  /* Clear mailbox.                 */
> > +    0x1400002d,   /* lu12i.w    $r13,1(0x1)         */
> > +    0x038081ad,   /* ori        $r13,$r13,0x20      */
> > +    0x06481da0,   /* iocsrwr.d  $r0,$r13            */
> > +
> > +                  /* Enable IPI interrupt.          */
> > +    0x1400002c,   /* lu12i.w    $r12,1(0x1)         */
> > +    0x0400118c,   /* csrxchg    $r12,$r12,0x4       */
> > +    0x02fffc0c,   /* addi.d     $r12,$r0,-1(0xfff)  */
> > +    0x1400002d,   /* lu12i.w    $r13,1(0x1)         */
> > +    0x038011ad,   /* ori        $r13,$r13,0x4       */
> > +    0x064819ac,   /* iocsrwr.w  $r12,$r13           */
> > +    0x1400002d,   /* lu12i.w    $r13,1(0x1)         */
> > +    0x038081ad,   /* ori        $r13,$r13,0x20      */
> > +
> > +                  /* Wait for wakeup  <.L11>:       */
> > +    0x06488000,   /* idle       0x0                 */
> > +    0x03400000,   /* andi       $r0,$r0,0x0         */
> > +    0x064809ac,   /* iocsrrd.w  $r12,$r13           */
> > +    0x43fff59f,   /* beqz       $r12,-12(0x7ffff4) # 48 <.L11> */
> > +
> > +                  /* Read and clear IPI interrupt.  */
> > +    0x1400002d,   /* lu12i.w    $r13,1(0x1)         */
> > +    0x064809ac,   /* iocsrrd.w  $r12,$r13           */
> > +    0x1400002d,   /* lu12i.w    $r13,1(0x1)         */
> > +    0x038031ad,   /* ori        $r13,$r13,0xc       */
> > +    0x064819ac,   /* iocsrwr.w  $r12,$r13           */
> > +
> > +                  /* Disable  IPI interrupt.        */
> > +    0x1400002c,   /* lu12i.w    $r12,1(0x1)         */
> > +    0x04001180,   /* csrxchg    $r0,$r12,0x4        */
> > +
> > +                  /* Read mail buf and jump to specified entry */
> > +    0x1400002d,   /* lu12i.w    $r13,1(0x1)         */
> > +    0x038081ad,   /* ori        $r13,$r13,0x20      */
> > +    0x06480dac,   /* iocsrrd.d  $r12,$r13           */
> > +    0x00150181,   /* move       $r1,$r12            */
> > +    0x4c000020,   /* jirl       $r0,$r1,0           */
> > +};
> > +
> >   static uint64_t cpu_loongarch_virt_to_phys(void *opaque, uint64_t 
> > addr)
> >   {
> >       return addr & MAKE_64BIT_MASK(0, TARGET_PHYS_ADDR_SPACE_BITS);
> > @@ -110,11 +158,19 @@ static void 
> > loongarch_firmware_boot(LoongArchMachineState *lams,
> >       fw_cfg_add_kernel_info(info, lams->fw_cfg);
> >   }
> >   +static void init_boot_rom(struct loongarch_boot_info *info, void *p)
> > +{
> > +    memcpy(p, &slave_boot_code, sizeof(slave_boot_code));
> > +    p += sizeof(slave_boot_code);
> > +}
> > +
> >   static void loongarch_direct_kernel_boot(struct loongarch_boot_info 
> > *info)
> >   {
> > +    static void  *p;
>
> Why 'static'?
I will drop it.
> >       int64_t kernel_addr = 0;
> >       LoongArchCPU *lacpu;
> >       CPUState *cs;
> > +    void *bp;
> >         if (info->kernel_filename) {
> >           kernel_addr = load_kernel_info(info);
> > @@ -123,11 +179,24 @@ static void loongarch_direct_kernel_boot(struct 
> > loongarch_boot_info *info)
> >           exit(1);
> >       }
> >   +    /* Load 'boot_rom' at [0 - 1MiB] */
> > +    p = g_malloc0(1 * MiB);
> > +    bp = p;
> > +    init_boot_rom(info, p);
> > +    rom_add_blob_fixed("boot_rom", bp, 1 * MiB, 0);
> > +
> >       CPU_FOREACH(cs) {
> >           lacpu = LOONGARCH_CPU(cs);
> >           lacpu->env.load_elf = true;
> > -        lacpu->env.elf_address = kernel_addr;
> > +        if (cs == first_cpu) {
> > +            lacpu->env.elf_address = kernel_addr;
> > +        } else {
> > +            lacpu->env.elf_address = 0;
> > +        }
> > +        lacpu->env.boot_info = info;
> >       }
> > +
> > +    g_free(bp);
>
> (besides, IIUC 'p' now points to released memory).
Yes.

Thanks.
Song Gao
> >   }
> >     void loongarch_load_kernel(MachineState *ms, struct 
> > loongarch_boot_info *info)