Re: [PATCH] target/loongarch: Support 4K page size

[maobibo]

在 2023/10/23 上午10:40, Song Gao 写道:
> The LoongArch kernel supports 4K page size.
> Change TARGET_PAGE_BITS to 12.
>
> Signed-off-by: Song Gao <gaosong@loongson.cn>
> ---
>   target/loongarch/cpu-param.h  | 2 +-
>   target/loongarch/tlb_helper.c | 9 ++++-----
>   2 files changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/target/loongarch/cpu-param.h b/target/loongarch/cpu-param.h
> index 1265dc7cb5..cfe195db4e 100644
> --- a/target/loongarch/cpu-param.h
> +++ b/target/loongarch/cpu-param.h
> @@ -12,6 +12,6 @@
>   #define TARGET_PHYS_ADDR_SPACE_BITS 48
>   #define TARGET_VIRT_ADDR_SPACE_BITS 48
>   
> -#define TARGET_PAGE_BITS 14
> +#define TARGET_PAGE_BITS 12
Hi Gaosong,

The popular OS about LoongArch still uses 16K page size, qemu should 
follow the rule of OS rather than defining 4K page size alone.

Regards
Bibo Mao

>   
>   #endif
> diff --git a/target/loongarch/tlb_helper.c b/target/loongarch/tlb_helper.c
> index c8b8b0497f..449043c68b 100644
> --- a/target/loongarch/tlb_helper.c
> +++ b/target/loongarch/tlb_helper.c
> @@ -60,6 +60,9 @@ static int loongarch_map_tlb_entry(CPULoongArchState *env, 
> hwaddr *physical,
>           tlb_rplv = 0;
>       }
>   
> +    /* Remove sw bit between bit12 -- bit PS*/
> +    tlb_ppn = tlb_ppn & ~(((0x1UL << (tlb_ps - 12)) -1));
> +
>       /* Check access rights */
>       if (!tlb_v) {
>           return TLBRET_INVALID;
> @@ -82,10 +85,6 @@ static int loongarch_map_tlb_entry(CPULoongArchState *env, 
> hwaddr *physical,
>           return TLBRET_DIRTY;
>       }
>   
> -    /*
> -     * tlb_entry contains ppn[47:12] while 16KiB ppn is [47:15]
> -     * need adjust.
> -     */
>       *physical = (tlb_ppn << R_TLBENTRY_64_PPN_SHIFT) |
>                   (address & MAKE_64BIT_MASK(0, tlb_ps));
>       *prot = PAGE_READ;
> @@ -774,7 +773,7 @@ void helper_ldpte(CPULoongArchState *env, target_ulong 
> base, target_ulong odd,
>           /* Move Global bit */
>           tmp0 = ((tmp0 & (1 << LOONGARCH_HGLOBAL_SHIFT))  >>
>                   LOONGARCH_HGLOBAL_SHIFT) << R_TLBENTRY_G_SHIFT |
> -                (tmp0 & (~(1 << R_TLBENTRY_G_SHIFT)));
> +                (tmp0 & (~(1 << LOONGARCH_HGLOBAL_SHIFT)));
>           ps = ptbase + ptwidth - 1;
>           if (odd) {
>               tmp0 += MAKE_64BIT_MASK(ps, 1);