From 85848dd7ab75fce1134856228582a8df522c91d9 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Mon, 13 Sep 2010 15:58:37 +0100 Subject: [PATCH] ARM: 6381/1: Use lazy cache flushing on ARMv7 SMP systems ARMv7 processors like Cortex-A9 broadcast the cache maintenance operations in hardware. This patch allows the flush_dcache_page/update_mmu_cache pair to work in lazy flushing mode similar to the UP case. Note that cache flushing on SMP systems now takes place via the set_pte_at() call (__sync_icache_dcache) and there is no race with other CPUs executing code from the new PTE before the cache flushing took place. Tested-by: Rabin Vincent Cc: Nicolas Pitre Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/include/asm/smp_plat.h | 4 ++++ arch/arm/mm/flush.c | 13 ++++--------- 2 files changed, 8 insertions(+), 9 deletions(-) diff --git a/arch/arm/include/asm/smp_plat.h b/arch/arm/include/asm/smp_plat.h index e6215305544a..963a338d567b 100644 --- a/arch/arm/include/asm/smp_plat.h +++ b/arch/arm/include/asm/smp_plat.h @@ -13,9 +13,13 @@ static inline int tlb_ops_need_broadcast(void) return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 2; } +#if !defined(CONFIG_SMP) || __LINUX_ARM_ARCH__ >= 7 +#define cache_ops_need_broadcast() 0 +#else static inline int cache_ops_need_broadcast(void) { return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 1; } +#endif #endif diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index dd5b0120b92e..2332b774c6b9 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -17,6 +17,7 @@ #include #include #include +#include #include "mm.h" @@ -93,12 +94,10 @@ void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsig #define flush_pfn_alias(pfn,vaddr) do { } while (0) #endif -#ifdef CONFIG_SMP static void flush_ptrace_access_other(void *args) { __flush_icache_all(); } -#endif static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page, @@ -122,11 +121,9 @@ void flush_ptrace_access(struct vm_area_struct *vma, struct page *page, if (vma->vm_flags & VM_EXEC) { unsigned long addr = (unsigned long)kaddr; __cpuc_coherent_kern_range(addr, addr + len); -#ifdef CONFIG_SMP if (cache_ops_need_broadcast()) smp_call_function(flush_ptrace_access_other, NULL, 1); -#endif } } @@ -276,12 +273,10 @@ void flush_dcache_page(struct page *page) mapping = page_mapping(page); -#ifndef CONFIG_SMP - if (mapping && !mapping_mapped(mapping)) + if (!cache_ops_need_broadcast() && + mapping && !mapping_mapped(mapping)) clear_bit(PG_dcache_clean, &page->flags); - else -#endif - { + else { __flush_dcache_page(mapping, page); if (mapping && cache_is_vivt()) __flush_dcache_aliases(mapping, page);