arm64: dcache_by_line_op to take end parameter instead of size

To be consistent with other functions with similar names and
functionality in cacheflush.h, cache.S, and cachetlb.rst, change
to specify the range in terms of start and end, as opposed to
start and size.

No functional change intended.
Reported-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20210524083001.2586635-12-tabba@google.comSigned-off-by: Will Deacon <will@kernel.org>

arch/arm64/include/asm/assembler.h

@@ -397,40 +397,39 @@ alternative_endif
 
 /*
  * Macro to perform a data cache maintenance for the interval
- * [addr, addr + size)
+ * [start, end)
  *
  * 	op:		operation passed to dc instruction
  * 	domain:		domain used in dsb instruciton
- * 	addr:		starting virtual address of the region
- * 	size:		size of the region
+ * 	start:          starting virtual address of the region
+ * 	end:            end virtual address of the region
  * 	fixup:		optional label to branch to on user fault
- * 	Corrupts:	addr, size, tmp1, tmp2
+ * 	Corrupts:       start, end, tmp1, tmp2
  */
-	.macro dcache_by_line_op op, domain, addr, size, tmp1, tmp2, fixup
+	.macro dcache_by_line_op op, domain, start, end, tmp1, tmp2, fixup
 	dcache_line_size \tmp1, \tmp2
-	add	\size, \addr, \size
 	sub	\tmp2, \tmp1, #1
-	bic	\addr, \addr, \tmp2
+	bic	\start, \start, \tmp2
 .Ldcache_op\@:
 	.ifc	\op, cvau
-	__dcache_op_workaround_clean_cache \op, \addr
+	__dcache_op_workaround_clean_cache \op, \start
 	.else
 	.ifc	\op, cvac
-	__dcache_op_workaround_clean_cache \op, \addr
+	__dcache_op_workaround_clean_cache \op, \start
 	.else
 	.ifc	\op, cvap
-	sys	3, c7, c12, 1, \addr	// dc cvap
+	sys	3, c7, c12, 1, \start	// dc cvap
 	.else
 	.ifc	\op, cvadp
-	sys	3, c7, c13, 1, \addr	// dc cvadp
+	sys	3, c7, c13, 1, \start	// dc cvadp
 	.else
-	dc	\op, \addr
+	dc	\op, \start
 	.endif
 	.endif
 	.endif
 	.endif
-	add	\addr, \addr, \tmp1
-	cmp	\addr, \size
+	add	\start, \start, \tmp1
+	cmp	\start, \end
 	b.lo	.Ldcache_op\@
 	dsb	\domain
 

arch/arm64/kvm/hyp/nvhe/cache.S

@@ -8,6 +8,7 @@
 #include <asm/alternative.h>
 
 SYM_FUNC_START_PI(__flush_dcache_area)
+	add	x1, x0, x1
 	dcache_by_line_op civac, sy, x0, x1, x2, x3
 	ret
 SYM_FUNC_END_PI(__flush_dcache_area)

arch/arm64/mm/cache.S

@@ -31,7 +31,7 @@ alternative_if ARM64_HAS_CACHE_IDC
 	b       .Ldc_skip_\@
 alternative_else_nop_endif
 	mov     x2, x0
-	sub     x3, x1, x0
+	mov     x3, x1
 	dcache_by_line_op cvau, ish, x2, x3, x4, x5, \fixup
 .Ldc_skip_\@:
 alternative_if ARM64_HAS_CACHE_DIC
@@ -108,6 +108,7 @@ SYM_FUNC_END(invalidate_icache_range)
  *	- size    - size in question
  */
 SYM_FUNC_START_PI(__flush_dcache_area)
+	add	x1, x0, x1
 	dcache_by_line_op civac, sy, x0, x1, x2, x3
 	ret
 SYM_FUNC_END_PI(__flush_dcache_area)
@@ -126,6 +127,7 @@ alternative_if ARM64_HAS_CACHE_IDC
 	dsb	ishst
 	ret
 alternative_else_nop_endif
+	add	x1, x0, x1
 	dcache_by_line_op cvau, ish, x0, x1, x2, x3
 	ret
 SYM_FUNC_END(__clean_dcache_area_pou)
@@ -187,6 +189,7 @@ SYM_FUNC_START_PI(__clean_dcache_area_poc)
  *	- start   - virtual start address of region
  *	- size    - size in question
  */
+	add	x1, x0, x1
 	dcache_by_line_op cvac, sy, x0, x1, x2, x3
 	ret
 SYM_FUNC_END_PI(__clean_dcache_area_poc)
@@ -205,6 +208,7 @@ SYM_FUNC_START_PI(__clean_dcache_area_pop)
 	alternative_if_not ARM64_HAS_DCPOP
 	b	__clean_dcache_area_poc
 	alternative_else_nop_endif
+	add	x1, x0, x1
 	dcache_by_line_op cvap, sy, x0, x1, x2, x3
 	ret
 SYM_FUNC_END_PI(__clean_dcache_area_pop)
@@ -218,6 +222,7 @@ SYM_FUNC_END_PI(__clean_dcache_area_pop)
  *	- size    - size in question
  */
 SYM_FUNC_START_PI(__dma_flush_area)
+	add	x1, x0, x1
 	dcache_by_line_op civac, sy, x0, x1, x2, x3
 	ret
 SYM_FUNC_END_PI(__dma_flush_area)