From: Catalin Marinas <catalin.marinas@arm.com>
Date: Tue, 9 Mar 2010 09:55:10 +0000 (+0000)
Subject: ARMv7: Use lazy cache flushing if hardware broadcasts cache operations
X-Git-Tag: firefly_0821_release~9833^2~171
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=bc07eb9db1944ccad5c4476cce2728e68abaf981;p=firefly-linux-kernel-4.4.55.git

ARMv7: Use lazy cache flushing if hardware broadcasts cache operations

ARMv7 processors like Cortex-A9 broadcast the cache maintenance
operations in hardware. The patch adds the CPU ID checks for such
feature and allows the flush_dcache_page/update_mmu_cache pair to work
in lazy flushing mode similar to the UP case.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---

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/fault-armv.c b/arch/arm/mm/fault-armv.c
index 9b906dec1ca1..9d77d90f4ade 100644
--- a/arch/arm/mm/fault-armv.c
+++ b/arch/arm/mm/fault-armv.c
@@ -168,10 +168,8 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr,
 		return;
 
 	mapping = page_mapping(page);
-#ifndef CONFIG_SMP
 	if (test_and_clear_bit(PG_dcache_dirty, &page->flags))
 		__flush_dcache_page(mapping, page);
-#endif
 	if (mapping) {
 		if (cache_is_vivt())
 			make_coherent(mapping, vma, addr, ptep, pfn);
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index c6844cb9b508..e0758968e9f8 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -17,6 +17,7 @@
 #include <asm/smp_plat.h>
 #include <asm/system.h>
 #include <asm/tlbflush.h>
+#include <asm/smp_plat.h>
 
 #include "mm.h"
 
@@ -246,12 +247,10 @@ void flush_dcache_page(struct page *page)
 
 	mapping = page_mapping(page);
 
-#ifndef CONFIG_SMP
-	if (!PageHighMem(page) && mapping && !mapping_mapped(mapping))
+	if (!cache_ops_need_broadcast() &&
+	    !PageHighMem(page) && mapping && !mapping_mapped(mapping))
 		set_bit(PG_dcache_dirty, &page->flags);
-	else
-#endif
-	{
+	else {
 		__flush_dcache_page(mapping, page);
 		if (mapping && cache_is_vivt())
 			__flush_dcache_aliases(mapping, page);