From 6a0e243069b09a323255f6e847c87d531961cd96 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Tue, 7 Mar 2006 14:42:27 +0000 Subject: [PATCH] [ARM] 3352/1: DSB required for the completion of a TLB maintenance operation Patch from Catalin Marinas Chapter B2.7.3 in the latest ARM ARM (with v6 information) states that the completion of a TLB maintenance operation is only guaranteed by the execution of a DSB (Data Syncronization Barrier, formerly Data Write Barrier or Drain Write Buffer). Note that a DSB is only needed in the flush_tlb_kernel_* functions since the completion is guaranteed by a mode change (i.e. switching back to user mode) for the flush_tlb_user_* functions. Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/Kconfig | 2 +- arch/arm/mm/tlb-v6.S | 1 + include/asm-arm/tlbflush.h | 6 ++++++ 3 files changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 15dc1a0dffbb..9f80fa502f8f 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -78,7 +78,7 @@ menu "System Type" choice prompt "ARM system type" - default ARCH_RPC + default ARCH_VERSATILE config ARCH_CLPS7500 bool "Cirrus-CL-PS7500FE" diff --git a/arch/arm/mm/tlb-v6.S b/arch/arm/mm/tlb-v6.S index 6f76b89ef46e..fd6adde39091 100644 --- a/arch/arm/mm/tlb-v6.S +++ b/arch/arm/mm/tlb-v6.S @@ -80,6 +80,7 @@ ENTRY(v6wbi_flush_kern_tlb_range) add r0, r0, #PAGE_SZ cmp r0, r1 blo 1b + mcr p15, 0, r2, c7, c10, 4 @ data synchronization barrier mov pc, lr .section ".text.init", #alloc, #execinstr diff --git a/include/asm-arm/tlbflush.h b/include/asm-arm/tlbflush.h index 9387a5e1ffe0..0c2acc944a0a 100644 --- a/include/asm-arm/tlbflush.h +++ b/include/asm-arm/tlbflush.h @@ -340,6 +340,12 @@ static inline void local_flush_tlb_kernel_page(unsigned long kaddr) asm("mcr%? p15, 0, %0, c8, c6, 1" : : "r" (kaddr)); if (tlb_flag(TLB_V6_I_PAGE)) asm("mcr%? p15, 0, %0, c8, c5, 1" : : "r" (kaddr)); + + /* The ARM ARM states that the completion of a TLB maintenance + * operation is only guaranteed by a DSB instruction + */ + if (tlb_flag(TLB_V6_U_PAGE | TLB_V6_D_PAGE | TLB_V6_I_PAGE)) + asm("mcr%? p15, 0, %0, c7, c10, 4" : : "r" (zero)); } /* -- 2.20.1