ARM: 8606/1: V7M: introduce cache operations

This commit implements the cache operation for V7M.

It is based on V7 counterpart and differs as follows:
- cache operations are memory mapped
- only Thumb instruction set is supported
- we don't handle user access faults
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Andras Szemzo <sza@esh.hu>
Tested-by: Joachim Eastwood <manabian@gmail.com>
Tested-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/proc-macros.S

@@ -7,6 +7,10 @@
 #include <asm/asm-offsets.h>
 #include <asm/thread_info.h>
 
+#ifdef CONFIG_CPU_V7M
+#include <asm/v7m.h>
+#endif
+
 /*
  * vma_vm_mm - get mm pointer from vma pointer (vma->vm_mm)
  */
@@ -70,7 +74,13 @@
  * on ARMv7.
  */
 	.macro	dcache_line_size, reg, tmp
+#ifdef CONFIG_CPU_V7M
+	movw	\tmp, #:lower16:BASEADDR_V7M_SCB + V7M_SCB_CTR
+	movt	\tmp, #:upper16:BASEADDR_V7M_SCB + V7M_SCB_CTR
+	ldr     \tmp, [\tmp]
+#else
 	mrc	p15, 0, \tmp, c0, c0, 1		@ read ctr
+#endif
 	lsr	\tmp, \tmp, #16
 	and	\tmp, \tmp, #0xf		@ cache line size encoding
 	mov	\reg, #4			@ bytes per word
@@ -82,7 +92,13 @@
  * on ARMv7.
  */
 	.macro	icache_line_size, reg, tmp
+#ifdef CONFIG_CPU_V7M
+	movw	\tmp, #:lower16:BASEADDR_V7M_SCB + V7M_SCB_CTR
+	movt	\tmp, #:upper16:BASEADDR_V7M_SCB + V7M_SCB_CTR
+	ldr     \tmp, [\tmp]
+#else
 	mrc	p15, 0, \tmp, c0, c0, 1		@ read ctr
+#endif
 	and	\tmp, \tmp, #0xf		@ cache line size encoding
 	mov	\reg, #4			@ bytes per word
 	mov	\reg, \reg, lsl \tmp		@ actual cache line size