[PATCH v3 6/7] ARM: EXYNOS: Add support for non-secure L2X0 resume

[Tomasz Figa]

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>
---
 arch/arm/mach-exynos/common.h   |  1 +
 arch/arm/mach-exynos/firmware.c |  2 ++
 arch/arm/mach-exynos/sleep.S    | 41 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+)

diff --git a/arch/arm/mach-exynos/common.h b/arch/arm/mach-exynos/common.h
index a3f3061..2540827 100644
--- a/arch/arm/mach-exynos/common.h
+++ b/arch/arm/mach-exynos/common.h
@@ -113,6 +113,7 @@ IS_SAMSUNG_CPU(exynos5800, EXYNOS5800_SOC_ID, EXYNOS5_SOC_MASK)
 
 extern u32 cp15_save_diag;
 extern u32 cp15_save_power;
+extern unsigned long l2x0_regs_phys;
 
 extern void __iomem *sysram_ns_base_addr;
 extern void __iomem *sysram_base_addr;
diff --git a/arch/arm/mach-exynos/firmware.c b/arch/arm/mach-exynos/firmware.c
index 554b350..09131d3 100644
--- a/arch/arm/mach-exynos/firmware.c
+++ b/arch/arm/mach-exynos/firmware.c
@@ -103,6 +103,8 @@ static int exynos_suspend(void)
 	writel(virt_to_phys(exynos_cpu_resume_ns),
 		sysram_ns_base_addr + EXYNOS_BOOT_ADDR);
 
+	l2x0_regs_phys = virt_to_phys(&l2x0_saved_regs);
+
 	return cpu_suspend(0, exynos_cpu_suspend);
 }
 
diff --git a/arch/arm/mach-exynos/sleep.S b/arch/arm/mach-exynos/sleep.S
index e3c3730..b8ce8f0 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 +76,40 @@ ENTRY(exynos_cpu_resume_ns)
 	mov	r0, #SMC_CMD_C15RESUME
 	dsb
 	smc	#0
+#ifdef CONFIG_CACHE_L2X0
+	adr	r0, l2x0_regs_phys
+	ldr	r0, [r0]
+	cmp	r0, #0
+	beq	skip_l2x0
+
+	ldr	r1, [r0, #L2X0_R_PHY_BASE]
+	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, l2x0_regs_phys
+	ldr	r0, [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 +119,8 @@ cp15_save_diag:
 	.globl cp15_save_power
 cp15_save_power:
 	.long	0	@ cp15 power control
+#ifdef CONFIG_CACHE_L2X0
+	.globl l2x0_regs_phys
+l2x0_regs_phys:
+	.long	0	@ phys address of l2x0 save struct
+#endif /* CONFIG_CACHE_L2X0 */
-- 
1.9.3