From: Soby Mathew <soby.mathew@arm.com>
Date: Thu, 15 Jun 2017 15:18:45 +0000 (+0100)
Subject: Exit early if size zero for cache helpers
X-Git-Url: http://git.openwrt.org/%22https:/collectd.org//%22http:/www.crowdsec.net/%22/%22https:/collectd.org/%22http:/www.crowdsec.net/%22?a=commitdiff_plain;h=3ec5204c49ddbc5c1142eda28106a572ca9ed9eb;p=project%2Fbcm63xx%2Fatf.git

Exit early if size zero for cache helpers

This patch enables cache helper functions `flush_dcache_range`,
`clean_dcache_range` and `invalidate_dcache_range` to exit early
if the size argument specified is zero

Change-Id: I0b63e8f4bd3d47ec08bf2a0b0b9a7ff8a269a9b0
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
---

diff --git a/lib/aarch32/cache_helpers.S b/lib/aarch32/cache_helpers.S
index 57b6b384..810af0f0 100644
--- a/lib/aarch32/cache_helpers.S
+++ b/lib/aarch32/cache_helpers.S
@@ -20,6 +20,9 @@
  * This macro can be used for implementing various data cache operations `op`
  */
 .macro do_dcache_maintenance_by_mva op, coproc, opc1, CRn, CRm, opc2
+	/* Exit early if size is zero */
+	cmp	r1, #0
+	beq	exit_loop_\op
 	dcache_line_size r2, r3
 	add	r1, r0, r1
 	sub	r3, r2, #1
@@ -30,6 +33,7 @@ loop_\op:
 	cmp	r0, r1
 	blo	loop_\op
 	dsb	sy
+exit_loop_\op:
 	bx	lr
 .endm
 
diff --git a/lib/aarch64/cache_helpers.S b/lib/aarch64/cache_helpers.S
index eef07a8b..9c40b9db 100644
--- a/lib/aarch64/cache_helpers.S
+++ b/lib/aarch64/cache_helpers.S
@@ -20,6 +20,8 @@
  * This macro can be used for implementing various data cache operations `op`
  */
 .macro do_dcache_maintenance_by_mva op
+	/* Exit early if size is zero */
+	cbz	x1, exit_loop_\op
 	dcache_line_size x2, x3
 	add	x1, x0, x1
 	sub	x3, x2, #1
@@ -30,6 +32,7 @@ loop_\op:
 	cmp	x0, x1
 	b.lo    loop_\op
 	dsb	sy
+exit_loop_\op:
 	ret
 .endm
 	/* ------------------------------------------