[PATCH v2 2/4] efi/arm: pass start and end addresses to cache_clean_flush()

[Ard Biesheuvel <ardb@kernel.org>]

In preparation for turning the decompressor's cache clean/flush
operations into proper by-VA maintenance for v7 cores, pass the
start and end addresses of the regions that need cache maintenance
into cache_clean_flush in registers r0 and r1.

Currently, all implementations of cache_clean_flush ignore these
values, so no functional change is expected as a result of this
patch.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm/boot/compressed/head.S | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 6c98d3d2de2f..c11b1b0a3ac6 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -1460,6 +1460,13 @@ ENTRY(efi_stub_entry)
 
 		@ Preserve return value of efi_entry() in r4
 		mov	r4, r0
+		add	r1, r4, #SZ_2M			@ DT end
+		bl	cache_clean_flush
+
+		ldr	r0, [sp]			@ relocated zImage
+		adr	r2, __edata
+		ldr	r1, [r2]
+		add	r1, r1, r2			@ end of image
 		bl	cache_clean_flush
 
 		@ The PE/COFF loader might not have cleaned the code we are
@@ -1489,6 +1496,8 @@ efi_load_fail:
 		ldr	r0, =0x80000001
 		ldmfd	sp!, {ip, pc}
 ENDPROC(efi_stub_entry)
+		.align	2
+__edata:	.long	_edata - .
 #endif
 
 		.align
-- 
2.17.1