Re: [PATCH RFC] MIPS: Build uasm-generated code only once to avoidCPU Hotplug problem

[Huacai Chen]

I'm sorry, this is the only patch, please ignore [01/14].

On Mon, Mar 4, 2013 at 8:56 PM, Huacai Chen <chenhc@xxxxxxxxxx> wrote:
> Currently, clear_page()/copy_page() are generated by Micro-assembler
> dynamically. But they are unavailable until uasm_resolve_relocs() has
> finished because jump labels are illegal before that. Since these
> functions are shared by every CPU, we only call build_clear_page()/
> build_copy_page() on CPU#0 at boot time. Without this patch, programs
> will get random memory corruption (segmentation fault, bus error, etc.)
> while CPU Hotplug (e.g. one CPU is using clear_page() while another is
> generating it in cpu_cache_init()).
>
> For similar reasons we modify build_tlb_refill_handler()'s invocation.
>
> Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
> Signed-off-by: Hongbing Hu <huhb@xxxxxxxxxx>
> ---
>  arch/mips/mm/c-octeon.c        |    6 ++++--
>  arch/mips/mm/c-r3k.c           |    6 ++++--
>  arch/mips/mm/c-r4k.c           |    6 ++++--
>  arch/mips/mm/c-tx39.c          |    6 ++++--
>  arch/mips/mm/tlb-r3k.c         |    3 ++-
>  arch/mips/mm/tlb-r4k.c         |    3 ++-
>  arch/mips/mm/tlb-r8k.c         |    3 ++-
>  arch/mips/sgi-ip27/ip27-init.c |    3 ++-
>  8 files changed, 24 insertions(+), 12 deletions(-)
>
> diff --git a/arch/mips/mm/c-octeon.c b/arch/mips/mm/c-octeon.c
> index 6ec04da..181a1bc 100644
> --- a/arch/mips/mm/c-octeon.c
> +++ b/arch/mips/mm/c-octeon.c
> @@ -280,8 +280,10 @@ void __cpuinit octeon_cache_init(void)
>
>         __flush_kernel_vmap_range       = octeon_flush_kernel_vmap_range;
>
> -       build_clear_page();
> -       build_copy_page();
> +       if (smp_processor_id() == 0) {
> +               build_clear_page();
> +               build_copy_page();
> +       }
>
>         board_cache_error_setup = octeon_cache_error_setup;
>  }
> diff --git a/arch/mips/mm/c-r3k.c b/arch/mips/mm/c-r3k.c
> index 031c4c2..b7b0cfd 100644
> --- a/arch/mips/mm/c-r3k.c
> +++ b/arch/mips/mm/c-r3k.c
> @@ -342,6 +342,8 @@ void __cpuinit r3k_cache_init(void)
>         printk("Primary data cache %ldkB, linesize %ld bytes.\n",
>                 dcache_size >> 10, dcache_lsize);
>
> -       build_clear_page();
> -       build_copy_page();
> +       if (smp_processor_id() == 0) {
> +               build_clear_page();
> +               build_copy_page();
> +       }
>  }
> diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
> index 5f9171d..3f671d6 100644
> --- a/arch/mips/mm/c-r4k.c
> +++ b/arch/mips/mm/c-r4k.c
> @@ -1548,8 +1548,10 @@ void __cpuinit r4k_cache_init(void)
>         }
>  #endif
>
> -       build_clear_page();
> -       build_copy_page();
> +       if (smp_processor_id() == 0) {
> +               build_clear_page();
> +               build_copy_page();
> +       }
>  #if !defined(CONFIG_MIPS_CMP)
>         local_r4k___flush_cache_all(NULL);
>  #endif
> diff --git a/arch/mips/mm/c-tx39.c b/arch/mips/mm/c-tx39.c
> index 87d23ca..1e42e12 100644
> --- a/arch/mips/mm/c-tx39.c
> +++ b/arch/mips/mm/c-tx39.c
> @@ -434,7 +434,9 @@ void __cpuinit tx39_cache_init(void)
>         printk("Primary data cache %ldkB, linesize %d bytes\n",
>                 dcache_size >> 10, current_cpu_data.dcache.linesz);
>
> -       build_clear_page();
> -       build_copy_page();
> +       if (smp_processor_id() == 0) {
> +               build_clear_page();
> +               build_copy_page();
> +       }
>         tx39h_flush_icache_all();
>  }
> diff --git a/arch/mips/mm/tlb-r3k.c b/arch/mips/mm/tlb-r3k.c
> index a63d1ed..86b4a79 100644
> --- a/arch/mips/mm/tlb-r3k.c
> +++ b/arch/mips/mm/tlb-r3k.c
> @@ -280,5 +280,6 @@ void __cpuinit tlb_init(void)
>  {
>         local_flush_tlb_all();
>
> -       build_tlb_refill_handler();
> +       if (smp_processor_id() == 0)
> +               build_tlb_refill_handler();
>  }
> diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
> index 0113330..db19624 100644
> --- a/arch/mips/mm/tlb-r4k.c
> +++ b/arch/mips/mm/tlb-r4k.c
> @@ -439,5 +439,6 @@ void __cpuinit tlb_init(void)
>                         printk("Ignoring invalid argument ntlb=%d\n", ntlb);
>         }
>
> -       build_tlb_refill_handler();
> +       if (smp_processor_id() == 0)
> +               build_tlb_refill_handler();
>  }
> diff --git a/arch/mips/mm/tlb-r8k.c b/arch/mips/mm/tlb-r8k.c
> index 91c2499..43fe634 100644
> --- a/arch/mips/mm/tlb-r8k.c
> +++ b/arch/mips/mm/tlb-r8k.c
> @@ -244,5 +244,6 @@ void __cpuinit tlb_init(void)
>
>         local_flush_tlb_all();
>
> -       build_tlb_refill_handler();
> +       if (smp_processor_id() == 0)
> +               build_tlb_refill_handler();
>  }
> diff --git a/arch/mips/sgi-ip27/ip27-init.c b/arch/mips/sgi-ip27/ip27-init.c
> index 923c080..62c41ab 100644
> --- a/arch/mips/sgi-ip27/ip27-init.c
> +++ b/arch/mips/sgi-ip27/ip27-init.c
> @@ -84,7 +84,8 @@ static void __cpuinit per_hub_init(cnodeid_t cnode)
>
>                 memcpy((void *)(CKSEG0 + 0x100), &except_vec2_generic, 0x80);
>                 memcpy((void *)(CKSEG0 + 0x180), &except_vec3_generic, 0x80);
> -               build_tlb_refill_handler();
> +               if (smp_processor_id() == 0)
> +                       build_tlb_refill_handler();
>                 memcpy((void *)(CKSEG0 + 0x100), (void *) CKSEG0, 0x80);
>                 memcpy((void *)(CKSEG0 + 0x180), &except_vec3_generic, 0x100);
>                 __flush_cache_all();
> --
> 1.7.7.3
>
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