From da30e0ac0f9a521f0cfec8145ddd1ad131f66d61 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Tue, 7 Dec 2010 16:56:29 +0100 Subject: [PATCH] ARM: 6528/1: Use CTR for the I-cache line size on ARMv7 The current implementation of the v7_coherent_*_range function assumes that the D and I cache lines have the same size, which is incorrect architecturally. This patch adds the icache_line_size macro which reads the CTR register. The main loop in v7_coherent_*_range is split in two independent loops or the D and I caches. This also has the performance advantage that the DSB is moved outside the main loop. Reported-by: Kevin Sapp Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/mm/cache-v7.S | 27 +++++++++++++++++---------- arch/arm/mm/proc-macros.S | 10 ++++++++++ 2 files changed, 27 insertions(+), 10 deletions(-) diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S index a3ebf7a4f49b..6136e68ce953 100644 --- a/arch/arm/mm/cache-v7.S +++ b/arch/arm/mm/cache-v7.S @@ -173,15 +173,22 @@ ENTRY(v7_coherent_user_range) UNWIND(.fnstart ) dcache_line_size r2, r3 sub r3, r2, #1 - bic r0, r0, r3 + bic r12, r0, r3 1: - USER( mcr p15, 0, r0, c7, c11, 1 ) @ clean D line to the point of unification + USER( mcr p15, 0, r12, c7, c11, 1 ) @ clean D line to the point of unification + add r12, r12, r2 + cmp r12, r1 + blo 1b dsb - USER( mcr p15, 0, r0, c7, c5, 1 ) @ invalidate I line - add r0, r0, r2 + icache_line_size r2, r3 + sub r3, r2, #1 + bic r12, r0, r3 2: - cmp r0, r1 - blo 1b + USER( mcr p15, 0, r12, c7, c5, 1 ) @ invalidate I line + add r12, r12, r2 + cmp r12, r1 + blo 2b +3: mov r0, #0 ALT_SMP(mcr p15, 0, r0, c7, c1, 6) @ invalidate BTB Inner Shareable ALT_UP(mcr p15, 0, r0, c7, c5, 6) @ invalidate BTB @@ -194,10 +201,10 @@ ENTRY(v7_coherent_user_range) * isn't mapped, just try the next page. */ 9001: - mov r0, r0, lsr #12 - mov r0, r0, lsl #12 - add r0, r0, #4096 - b 2b + mov r12, r12, lsr #12 + mov r12, r12, lsl #12 + add r12, r12, #4096 + b 3b UNWIND(.fnend ) ENDPROC(v7_coherent_kern_range) ENDPROC(v7_coherent_user_range) diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S index 321555b894d1..b795afd0a2c6 100644 --- a/arch/arm/mm/proc-macros.S +++ b/arch/arm/mm/proc-macros.S @@ -72,6 +72,16 @@ mov \reg, \reg, lsl \tmp @ actual cache line size .endm +/* + * icache_line_size - get the minimum I-cache line size from the CTR register + * on ARMv7. + */ + .macro icache_line_size, reg, tmp + mrc p15, 0, \tmp, c0, c0, 1 @ read ctr + and \tmp, \tmp, #0xf @ cache line size encoding + mov \reg, #4 @ bytes per word + mov \reg, \reg, lsl \tmp @ actual cache line size + .endm /* * Sanity check the PTE configuration for the code below - which makes -- 2.39.5