[RFC PATCH v2] ARM: OMAP4/highbank: Flush L2 cache before disabling

[Taras Kondratiuk]

Kexec disables outer cache before jumping to reboot code, but it doesn't
flush it explicitly. Flush is done implicitly inside of l2x0_disable().
But some SoC's override default .disable handler and don't flush cache.
This may lead to a corrupted memory during Kexec reboot on these platforms.

This patch adds cache flush inside of OMAP4 and Highbank outer_cache.disable()
handlers to make it consistent with default l2x0_disable().
Also it removes redundant outer_flush_all() call just before outer_disable().

Signed-off-by: Taras Kondratiuk <taras.kondratiuk at linaro.org>
---
v2: Make the fix specific to platforms that don't use l2x0_disable().
v1: https://patchwork.kernel.org/patch/2974431/
---
Cc: Will Deacon <will.deacon at arm.com>
Cc: Russell King <linux at arm.linux.org.uk>
Cc: Rob Herring <rob.herring at calxeda.com>
Cc: linaro-kernel at lists.linaro.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-omap at vger.kernel.org
---
arch/arm/mach-highbank/highbank.c  |    1 +
arch/arm/mach-highbank/pm.c        |    1 -
arch/arm/mach-omap2/omap4-common.c |    1 +
 3 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-highbank/highbank.c b/arch/arm/mach-highbank/highbank.c
index 8e63ccd..22e6f34 100644
--- a/arch/arm/mach-highbank/highbank.c
+++ b/arch/arm/mach-highbank/highbank.c
@@ -63,6 +63,7 @@ void highbank_set_cpu_jump(int cpu, void *jump_addr)
 
 static void highbank_l2x0_disable(void)
 {
+	outer_flush_all();
 	/* Disable PL310 L2 Cache controller */
 	highbank_smc1(0x102, 0x0);
 }
diff --git a/arch/arm/mach-highbank/pm.c b/arch/arm/mach-highbank/pm.c
index 04eddb4..9a5b8a7 100644
--- a/arch/arm/mach-highbank/pm.c
+++ b/arch/arm/mach-highbank/pm.c
@@ -28,7 +28,6 @@
 
 static int highbank_suspend_finish(unsigned long val)
 {
-	outer_flush_all();
 	outer_disable();
 
 	highbank_set_pwr_suspend();
diff --git a/arch/arm/mach-omap2/omap4-common.c b/arch/arm/mach-omap2/omap4-common.c
index 5791143..3f44b16 100644
--- a/arch/arm/mach-omap2/omap4-common.c
+++ b/arch/arm/mach-omap2/omap4-common.c
@@ -163,6 +163,7 @@ void __iomem *omap4_get_l2cache_base(void)
 
 static void omap4_l2x0_disable(void)
 {
+	outer_flush_all();
 	/* Disable PL310 L2 Cache controller */
 	omap_smc1(0x102, 0x0);
 }
-- 
1.7.9.5