ARM: 6527/1: Use CTR instead of CCSIDR for the D-cache line size on ARMv7

The current implementation of the dcache_line_size macro reads the L1
cache size from the CCSIDR register. This, however, is not guaranteed to
be the smallest cache line in the cache hierarchy. The patch changes to
the macro to use the more architecturally correct CTR register.

Reported-by: Kevin Sapp <ksapp@quicinc.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
index 7d63bea..321555b 100644 (file)
--- a/arch/arm/mm/proc-macros.S
+++ b/arch/arm/mm/proc-macros.S
@@ -61,14 +61,14 @@
        .endm
 
 /*
- * cache_line_size - get the cache line size from the CSIDR register
- * (available on ARMv7+). It assumes that the CSSR register was configured
- * to access the L1 data cache CSIDR.
+ * dcache_line_size - get the minimum D-cache line size from the CTR register
+ * on ARMv7.
  */
        .macro  dcache_line_size, reg, tmp
-       mrc     p15, 1, \tmp, c0, c0, 0         @ read CSIDR
-       and     \tmp, \tmp, #7                  @ cache line size encoding
-       mov     \reg, #16                       @ size offset
+       mrc     p15, 0, \tmp, c0, c0, 1         @ read ctr
+       lsr     \tmp, \tmp, #16
+       and     \tmp, \tmp, #0xf                @ cache line size encoding
+       mov     \reg, #4                        @ bytes per word
        mov     \reg, \reg, lsl \tmp            @ actual cache line size
        .endm