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>

arch/arm/mm/proc-macros.S

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