From 7f3f1d01a9020cff2cb2390aaee3f8df0d70e203 Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Fri, 12 May 2006 13:20:06 +0100 Subject: [PATCH] [MIPS] Fix deadlock on MP with cache aliases. A proper fix would involve introducing the notion of shared caches but at this stage of 2.6.17 that's going to be too intrusive and not needed for current hardware; aside I think some discussion will be needed. So for now on the affected SMP configurations which happen to suffer from cache aliases we make use of the fact that a single cache will be shared by all processors. This solves the deadlock issue and will improve performance by getting rid of the smp_call_function overhead. Signed-off-by: Ralf Baechle --- arch/mips/mm/c-r4k.c | 39 ++++++++++++++++++++++++++++++--------- 1 file changed, 30 insertions(+), 9 deletions(-) diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c index 4420191795f3..570bc4e30fd5 100644 --- a/arch/mips/mm/c-r4k.c +++ b/arch/mips/mm/c-r4k.c @@ -29,6 +29,27 @@ #include #include /* for run_uncached() */ + +/* + * Special Variant of smp_call_function for use by cache functions: + * + * o No return value + * o collapses to normal function call on UP kernels + * o collapses to normal function call on systems with a single shared + * primary cache. + */ +static inline void r4k_on_each_cpu(void (*func) (void *info), void *info, + int retry, int wait) +{ + preempt_disable(); + +#if !defined(CONFIG_MIPS_MT_SMP) && !defined(CONFIG_MIPS_MT_SMTC) + smp_call_function(func, info, retry, wait); +#endif + func(info); + preempt_enable(); +} + /* * Must die. */ @@ -299,7 +320,7 @@ static void r4k_flush_cache_all(void) if (!cpu_has_dc_aliases) return; - on_each_cpu(local_r4k_flush_cache_all, NULL, 1, 1); + r4k_on_each_cpu(local_r4k_flush_cache_all, NULL, 1, 1); } static inline void local_r4k___flush_cache_all(void * args) @@ -320,7 +341,7 @@ static inline void local_r4k___flush_cache_all(void * args) static void r4k___flush_cache_all(void) { - on_each_cpu(local_r4k___flush_cache_all, NULL, 1, 1); + r4k_on_each_cpu(local_r4k___flush_cache_all, NULL, 1, 1); } static inline void local_r4k_flush_cache_range(void * args) @@ -341,7 +362,7 @@ static inline void local_r4k_flush_cache_range(void * args) static void r4k_flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { - on_each_cpu(local_r4k_flush_cache_range, vma, 1, 1); + r4k_on_each_cpu(local_r4k_flush_cache_range, vma, 1, 1); } static inline void local_r4k_flush_cache_mm(void * args) @@ -370,7 +391,7 @@ static void r4k_flush_cache_mm(struct mm_struct *mm) if (!cpu_has_dc_aliases) return; - on_each_cpu(local_r4k_flush_cache_mm, mm, 1, 1); + r4k_on_each_cpu(local_r4k_flush_cache_mm, mm, 1, 1); } struct flush_cache_page_args { @@ -461,7 +482,7 @@ static void r4k_flush_cache_page(struct vm_area_struct *vma, args.addr = addr; args.pfn = pfn; - on_each_cpu(local_r4k_flush_cache_page, &args, 1, 1); + r4k_on_each_cpu(local_r4k_flush_cache_page, &args, 1, 1); } static inline void local_r4k_flush_data_cache_page(void * addr) @@ -471,7 +492,7 @@ static inline void local_r4k_flush_data_cache_page(void * addr) static void r4k_flush_data_cache_page(unsigned long addr) { - on_each_cpu(local_r4k_flush_data_cache_page, (void *) addr, 1, 1); + r4k_on_each_cpu(local_r4k_flush_data_cache_page, (void *) addr, 1, 1); } struct flush_icache_range_args { @@ -514,7 +535,7 @@ static void r4k_flush_icache_range(unsigned long start, unsigned long end) args.start = start; args.end = end; - on_each_cpu(local_r4k_flush_icache_range, &args, 1, 1); + r4k_on_each_cpu(local_r4k_flush_icache_range, &args, 1, 1); instruction_hazard(); } @@ -590,7 +611,7 @@ static void r4k_flush_icache_page(struct vm_area_struct *vma, args.vma = vma; args.page = page; - on_each_cpu(local_r4k_flush_icache_page, &args, 1, 1); + r4k_on_each_cpu(local_r4k_flush_icache_page, &args, 1, 1); } @@ -689,7 +710,7 @@ static void local_r4k_flush_cache_sigtramp(void * arg) static void r4k_flush_cache_sigtramp(unsigned long addr) { - on_each_cpu(local_r4k_flush_cache_sigtramp, (void *) addr, 1, 1); + r4k_on_each_cpu(local_r4k_flush_cache_sigtramp, (void *) addr, 1, 1); } static void r4k_flush_icache_all(void) -- 2.20.1