[PATCH v12 8/9] ARM: EXYNOS: Add support for non-secure L2X0 resume

[Marek Szyprowski]

From: Tomasz Figa <t.figa at samsung.com>

On Exynos SoCs it is necessary to resume operation of L2C early in
assembly code, because otherwise certain systems will crash. This patch
adds necessary code to non-secure resume handler.

Signed-off-by: Tomasz Figa <t.figa at samsung.com>
[rewrote the code accessing l2x0_saved_regs]
Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
Acked-by: Arnd Bergmann <arnd at arndb.de>
Acked-by: Kukjin Kim <kgene.kim at samsung.com>
---
 arch/arm/mach-exynos/sleep.S | 46 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/arch/arm/mach-exynos/sleep.S b/arch/arm/mach-exynos/sleep.S
index e3c373082bbe..31d25834b9c4 100644
--- a/arch/arm/mach-exynos/sleep.S
+++ b/arch/arm/mach-exynos/sleep.S
@@ -16,6 +16,8 @@
  */
 
 #include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/hardware/cache-l2x0.h>
 #include "smc.h"
 
 #define CPU_MASK	0xff0ffff0
@@ -74,6 +76,45 @@ ENTRY(exynos_cpu_resume_ns)
 	mov	r0, #SMC_CMD_C15RESUME
 	dsb
 	smc	#0
+#ifdef CONFIG_CACHE_L2X0
+	adr	r0, 1f
+	ldr	r2, [r0]
+	add	r0, r2, r0
+
+	/* Check that the address has been initialised. */
+	ldr	r1, [r0, #L2X0_R_PHY_BASE]
+	teq	r1, #0
+	beq	skip_l2x0
+
+	/* Check if controller has been enabled. */
+	ldr	r2, [r1, #L2X0_CTRL]
+	tst	r2, #0x1
+	bne	skip_l2x0
+
+	ldr	r1, [r0, #L2X0_R_TAG_LATENCY]
+	ldr	r2, [r0, #L2X0_R_DATA_LATENCY]
+	ldr	r3, [r0, #L2X0_R_PREFETCH_CTRL]
+	mov	r0, #SMC_CMD_L2X0SETUP1
+	smc	#0
+
+	/* Reload saved regs pointer because smc corrupts registers. */
+	adr	r0, 1f
+	ldr	r2, [r0]
+	add	r0, r2, r0
+
+	ldr	r1, [r0, #L2X0_R_PWR_CTRL]
+	ldr	r2, [r0, #L2X0_R_AUX_CTRL]
+	mov	r0, #SMC_CMD_L2X0SETUP2
+	smc	#0
+
+	mov	r0, #SMC_CMD_L2X0INVALL
+	smc	#0
+
+	mov	r1, #1
+	mov	r0, #SMC_CMD_L2X0CTRL
+	smc	#0
+skip_l2x0:
+#endif /* CONFIG_CACHE_L2X0 */
 skip_cp15:
 	b	cpu_resume
 ENDPROC(exynos_cpu_resume_ns)
@@ -83,3 +124,8 @@ cp15_save_diag:
 	.globl cp15_save_power
 cp15_save_power:
 	.long	0	@ cp15 power control
+
+#ifdef CONFIG_CACHE_L2X0
+	.align
+1:	.long	l2x0_saved_regs - .
+#endif /* CONFIG_CACHE_L2X0 */
-- 
1.9.2