From 6744ace5b3831939e1f4f487946a6f823df00e1d Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 7 Jul 2020 12:07:07 +0200 Subject: [PATCH] arm: enable allocate-on-read for LPAE's DCACHE_WRITEBACK/_WRITETHROUGH The LPAE versions of DCACHE_WRITEBACK and DCACHE_WRITETHROUGH are currently defined as no-allocate for both reads and writes, which deviates from the non-LPAE definition, and mostly defeats the purpose of enabling the caches in the first place. So align LPAE with !LPAE, and enable allocate-on-read for both. And while at it, add some clarification about the meaning of the chosen values. Signed-off-by: Ard Biesheuvel Reviewed-by: Andre Przywara --- arch/arm/include/asm/system.h | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h index 37c1bfd726..ce552944b7 100644 --- a/arch/arm/include/asm/system.h +++ b/arch/arm/include/asm/system.h @@ -445,10 +445,16 @@ static inline void set_dacr(unsigned int val) #define TTBCR_EPD0 (0 << 7) /* - * Memory types + * VMSAv8-32 Long-descriptor format memory region attributes + * (ARM Architecture Reference Manual section G5.7.4 [DDI0487E.a]) + * + * MAIR0[ 7: 0] 0x00 Device-nGnRnE (aka Strongly-Ordered) + * MAIR0[15: 8] 0xaa Outer/Inner Write-Through, Read-Allocate No Write-Allocate + * MAIR0[23:16] 0xee Outer/Inner Write-Back, Read-Allocate No Write-Allocate + * MAIR0[31:24] 0xff Outer/Inner Write-Back, Read-Allocate Write-Allocate */ -#define MEMORY_ATTRIBUTES ((0x00 << (0 * 8)) | (0x88 << (1 * 8)) | \ - (0xcc << (2 * 8)) | (0xff << (3 * 8))) +#define MEMORY_ATTRIBUTES ((0x00 << (0 * 8)) | (0xaa << (1 * 8)) | \ + (0xee << (2 * 8)) | (0xff << (3 * 8))) /* options available for data cache on each page */ enum dcache_option { @@ -471,7 +477,16 @@ enum dcache_option { #define TTB_SECT_B_MASK (1 << 2) #define TTB_SECT (2 << 0) -/* options available for data cache on each page */ +/* + * Short-descriptor format memory region attributes, without TEX remap + * (ARM Architecture Reference Manual section G5.7.2 [DDI0487E.a]) + * + * TEX[0] C B + * 0 0 0 Device-nGnRnE (aka Strongly-Ordered) + * 0 1 0 Outer/Inner Write-Through, Read-Allocate No Write-Allocate + * 0 1 1 Outer/Inner Write-Back, Read-Allocate No Write-Allocate + * 1 1 1 Outer/Inner Write-Back, Read-Allocate Write-Allocate + */ enum dcache_option { DCACHE_OFF = TTB_SECT_DOMAIN(0) | TTB_SECT_XN_MASK | TTB_SECT, DCACHE_WRITETHROUGH = DCACHE_OFF | TTB_SECT_C_MASK, -- 2.39.5