[PATCH] ARM: Thumb-2: Enable ARM/Thumb interworking for v7 cache maintenance

[dave.martin@linaro.org (Dave Martin)]

Cache maintenence functions may need to be called from low-level
platform code (such as for omap3).

Some low-level code may need to be built as ARM code even in a Thumb-2
kernel, if the code needs to talk to a non-Thumb-2-aware bootloader
or firmware (again, omap3 is an example).

In order to avoid the need for complex hacks to make calling
these cache maintenance routines work, simply use "bx lr" to
return from these functions.

There's no risk of build failures, since mm/*-v7.S are by definition
built with -march=armv7-a.

bx lr always does the right thing for a pure ARM kernel, so we
shouldn't need any conditional assembly here.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
---
 arch/arm/mm/cache-v7.S |   20 ++++++++++----------
 1 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index 6136e68..a5e5aa1 100644
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -29,7 +29,7 @@ ENTRY(v7_flush_icache_all)
 	mov	r0, #0
 	ALT_SMP(mcr	p15, 0, r0, c7, c1, 0)		@ invalidate I-cache inner shareable
 	ALT_UP(mcr	p15, 0, r0, c7, c5, 0)		@ I+BTB cache invalidate
-	mov	pc, lr
+	bx	lr
 ENDPROC(v7_flush_icache_all)
 
 /*
@@ -87,7 +87,7 @@ finished:
 	mcr	p15, 2, r10, c0, c0, 0		@ select current cache level in cssr
 	dsb
 	isb
-	mov	pc, lr
+	bx	lr
 ENDPROC(v7_flush_dcache_all)
 
 /*
@@ -110,7 +110,7 @@ ENTRY(v7_flush_kern_cache_all)
 	ALT_UP(mcr	p15, 0, r0, c7, c5, 0)	@ I+BTB cache invalidate
  ARM(	ldmfd	sp!, {r4-r5, r7, r9-r11, lr}	)
  THUMB(	ldmfd	sp!, {r4-r7, r9-r11, lr}	)
-	mov	pc, lr
+	bx	lr
 ENDPROC(v7_flush_kern_cache_all)
 
 /*
@@ -136,7 +136,7 @@ ENTRY(v7_flush_user_cache_all)
  *	- we have a VIPT cache.
  */
 ENTRY(v7_flush_user_cache_range)
-	mov	pc, lr
+	bx	lr
 ENDPROC(v7_flush_user_cache_all)
 ENDPROC(v7_flush_user_cache_range)
 
@@ -194,7 +194,7 @@ ENTRY(v7_coherent_user_range)
 	ALT_UP(mcr	p15, 0, r0, c7, c5, 6)	@ invalidate BTB
 	dsb
 	isb
-	mov	pc, lr
+	bx	lr
 
 /*
  * Fault handling for the cache operation above. If the virtual address in r0
@@ -227,7 +227,7 @@ ENTRY(v7_flush_kern_dcache_area)
 	cmp	r0, r1
 	blo	1b
 	dsb
-	mov	pc, lr
+	bx	lr
 ENDPROC(v7_flush_kern_dcache_area)
 
 /*
@@ -256,7 +256,7 @@ v7_dma_inv_range:
 	cmp	r0, r1
 	blo	1b
 	dsb
-	mov	pc, lr
+	bx	lr
 ENDPROC(v7_dma_inv_range)
 
 /*
@@ -274,7 +274,7 @@ v7_dma_clean_range:
 	cmp	r0, r1
 	blo	1b
 	dsb
-	mov	pc, lr
+	bx	lr
 ENDPROC(v7_dma_clean_range)
 
 /*
@@ -292,7 +292,7 @@ ENTRY(v7_dma_flush_range)
 	cmp	r0, r1
 	blo	1b
 	dsb
-	mov	pc, lr
+	bx	lr
 ENDPROC(v7_dma_flush_range)
 
 /*
@@ -318,7 +318,7 @@ ENTRY(v7_dma_unmap_area)
 	add	r1, r1, r0
 	teq	r2, #DMA_TO_DEVICE
 	bne	v7_dma_inv_range
-	mov	pc, lr
+	bx	lr
 ENDPROC(v7_dma_unmap_area)
 
 	__INITDATA
-- 
1.7.1