From: David Daney <ddaney.cavm@gmail.com>
To: Huacai Chen <chenhc@lemote.com>, Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org, linux-kernel@vger.kernel.org,
Fuxin Zhang <zhangfx@lemote.com>,
Zhangjin Wu <wuzhangjin@gmail.com>, Hongbing Hu <huhb@lemote.com>
Subject: Re: [PATCH V2 01/02] MIPS: Build uasm-generated code only once to avoid CPU Hotplug problem
Date: Thu, 21 Mar 2013 08:53:50 -0700 [thread overview]
Message-ID: <514B2D0E.808@gmail.com> (raw)
In-Reply-To: <514A42F2.4080501@gmail.com>
On 03/20/2013 04:14 PM, David Daney wrote:
> On 03/17/2013 05:49 AM, Huacai Chen wrote:
>> This and the next patch resolve memory corruption problems while CPU
>> hotplug. Without these patches, memory corruption can triggered easily
>> as below:
>>
[...]
>
> We were seeing the same crashes, this patch set seems to fix the problem.
>
> Acked-by: David Daney <david.daney@cavium.com>
On second thought...
>
>> ---
>> arch/mips/include/asm/cpu-features.h | 3 +++
>> .../asm/mach-loongson/cpu-feature-overrides.h | 1 +
>> arch/mips/mm/page.c | 10 ++++++++++
>> arch/mips/mm/tlbex.c | 10 ++++++++--
>> 4 files changed, 22 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/mips/include/asm/cpu-features.h
>> b/arch/mips/include/asm/cpu-features.h
>> index 1a57e8b..e5ec8fc 100644
>> --- a/arch/mips/include/asm/cpu-features.h
>> +++ b/arch/mips/include/asm/cpu-features.h
>> @@ -113,6 +113,9 @@
>> #ifndef cpu_has_pindexed_dcache
>> #define cpu_has_pindexed_dcache (cpu_data[0].dcache.flags &
>> MIPS_CACHE_PINDEX)
>> #endif
>> +#ifndef cpu_has_local_ebase
>> +#define cpu_has_local_ebase 1
This really should default to 0 and only be set for (??who knows what??).
David Daney
>> +#endif
>>
>> /*
>> * I-Cache snoops remote store. This only matters on SMP. Some
>> multiprocessors
>> diff --git
>> a/arch/mips/include/asm/mach-loongson/cpu-feature-overrides.h
>> b/arch/mips/include/asm/mach-loongson/cpu-feature-overrides.h
>> index 75fd8c0..c0f3ef4 100644
>> --- a/arch/mips/include/asm/mach-loongson/cpu-feature-overrides.h
>> +++ b/arch/mips/include/asm/mach-loongson/cpu-feature-overrides.h
>> @@ -57,5 +57,6 @@
>> #define cpu_has_vint 0
>> #define cpu_has_vtag_icache 0
>> #define cpu_has_watch 1
>> +#define cpu_has_local_ebase 0
>>
>> #endif /* __ASM_MACH_LOONGSON_CPU_FEATURE_OVERRIDES_H */
>> diff --git a/arch/mips/mm/page.c b/arch/mips/mm/page.c
>> index a29fba5..4eb8dcf 100644
>> --- a/arch/mips/mm/page.c
>> +++ b/arch/mips/mm/page.c
>> @@ -247,6 +247,11 @@ void __cpuinit build_clear_page(void)
>> struct uasm_label *l = labels;
>> struct uasm_reloc *r = relocs;
>> int i;
>> + static atomic_t run_once = ATOMIC_INIT(0);
>> +
>> + if (atomic_xchg(&run_once, 1)) {
>> + return;
>> + }
>>
>> memset(labels, 0, sizeof(labels));
>> memset(relocs, 0, sizeof(relocs));
>> @@ -389,6 +394,11 @@ void __cpuinit build_copy_page(void)
>> struct uasm_label *l = labels;
>> struct uasm_reloc *r = relocs;
>> int i;
>> + static atomic_t run_once = ATOMIC_INIT(0);
>> +
>> + if (atomic_xchg(&run_once, 1)) {
>> + return;
>> + }
>>
>> memset(labels, 0, sizeof(labels));
>> memset(relocs, 0, sizeof(relocs));
>> diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
>> index 820e661..6bc28b4 100644
>> --- a/arch/mips/mm/tlbex.c
>> +++ b/arch/mips/mm/tlbex.c
>> @@ -2162,8 +2162,11 @@ void __cpuinit build_tlb_refill_handler(void)
>> case CPU_TX3922:
>> case CPU_TX3927:
>> #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
>> - build_r3000_tlb_refill_handler();
>> + if (cpu_has_local_ebase)
>> + build_r3000_tlb_refill_handler();
>> if (!run_once) {
>> + if (!cpu_has_local_ebase)
>> + build_r3000_tlb_refill_handler();
>> build_r3000_tlb_load_handler();
>> build_r3000_tlb_store_handler();
>> build_r3000_tlb_modify_handler();
>> @@ -2192,9 +2195,12 @@ void __cpuinit build_tlb_refill_handler(void)
>> build_r4000_tlb_load_handler();
>> build_r4000_tlb_store_handler();
>> build_r4000_tlb_modify_handler();
>> + if (!cpu_has_local_ebase)
>> + build_r4000_tlb_refill_handler();
>> run_once++;
>> }
>> - build_r4000_tlb_refill_handler();
>> + if (cpu_has_local_ebase)
>> + build_r4000_tlb_refill_handler();
>> }
>> }
>>
>>
>
next prev parent reply other threads:[~2013-03-21 15:53 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-17 12:49 [PATCH V2 01/02] MIPS: Build uasm-generated code only once to avoid CPU Hotplug problem Huacai Chen
2013-03-20 23:14 ` David Daney
2013-03-21 15:53 ` David Daney [this message]
2013-03-22 0:56 ` Huacai Chen
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