ARM: EXYNOS: save L2 settings during bootup

This patch adds code to save L2 register configuration at boot, and
later used to resume L2 before MMU is enabled in suspend and cpuidle
resume paths.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-exynos/common.c

@@ -26,10 +26,12 @@
 #include <asm/hardware/gic.h>
 #include <asm/mach/map.h>
 #include <asm/mach/irq.h>
+#include <asm/cacheflush.h>
 
 #include <mach/regs-irq.h>
 #include <mach/regs-pmu.h>
 #include <mach/regs-gpio.h>
+#include <mach/pmu.h>
 
 #include <plat/cpu.h>
 #include <plat/clock.h>
@@ -441,20 +443,38 @@ core_initcall(exynos4_core_init);
 #ifdef CONFIG_CACHE_L2X0
 static int __init exynos4_l2x0_cache_init(void)
 {
-	/* TAG, Data Latency Control: 2cycle */
-	__raw_writel(0x110, S5P_VA_L2CC + L2X0_TAG_LATENCY_CTRL);
+	if (!(__raw_readl(S5P_VA_L2CC + L2X0_CTRL) & 0x1)) {
+		l2x0_saved_regs.phy_base = EXYNOS4_PA_L2CC;
+		/* TAG, Data Latency Control: 2 cycles */
+		l2x0_saved_regs.tag_latency = 0x110;
 
-	if (soc_is_exynos4210())
-		__raw_writel(0x110, S5P_VA_L2CC + L2X0_DATA_LATENCY_CTRL);
-	else if (soc_is_exynos4212() || soc_is_exynos4412())
-		__raw_writel(0x120, S5P_VA_L2CC + L2X0_DATA_LATENCY_CTRL);
+		if (soc_is_exynos4212() || soc_is_exynos4412())
+			l2x0_saved_regs.data_latency = 0x120;
+		else
+			l2x0_saved_regs.data_latency = 0x110;
+
+		l2x0_saved_regs.prefetch_ctrl = 0x30000007;
+		l2x0_saved_regs.pwr_ctrl =
+			(L2X0_DYNAMIC_CLK_GATING_EN | L2X0_STNDBY_MODE_EN);
+
+		l2x0_regs_phys = virt_to_phys(&l2x0_saved_regs);
 
-	/* L2X0 Prefetch Control */
-	__raw_writel(0x30000007, S5P_VA_L2CC + L2X0_PREFETCH_CTRL);
+		__raw_writel(l2x0_saved_regs.tag_latency,
+				S5P_VA_L2CC + L2X0_TAG_LATENCY_CTRL);
+		__raw_writel(l2x0_saved_regs.data_latency,
+				S5P_VA_L2CC + L2X0_DATA_LATENCY_CTRL);
 
-	/* L2X0 Power Control */
-	__raw_writel(L2X0_DYNAMIC_CLK_GATING_EN | L2X0_STNDBY_MODE_EN,
-		     S5P_VA_L2CC + L2X0_POWER_CTRL);
+		/* L2X0 Prefetch Control */
+		__raw_writel(l2x0_saved_regs.prefetch_ctrl,
+				S5P_VA_L2CC + L2X0_PREFETCH_CTRL);
+
+		/* L2X0 Power Control */
+		__raw_writel(l2x0_saved_regs.pwr_ctrl,
+				S5P_VA_L2CC + L2X0_POWER_CTRL);
+
+		clean_dcache_area(&l2x0_regs_phys, sizeof(unsigned long));
+		clean_dcache_area(&l2x0_saved_regs, sizeof(struct l2x0_regs));
+	}
 
 	l2x0_init(S5P_VA_L2CC, 0x7C470001, 0xC200ffff);