ARM: exynos: Add CPU state management for Exynos542x under secure firmware

Add required CPU state management done via secure monitor call for
Exynos542x running unsed Secure Firmware.
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
[mszyprow: rewrote code to use defines and sysram base address instead
 of the magic numbers, added second smc call in pm_resume, rephrased
 subject and commit message]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

arch/arm/mach-exynos/common.h

@@ -91,6 +91,7 @@ extern u32 cp15_save_power;
 
 extern void __iomem *sysram_ns_base_addr;
 extern void __iomem *sysram_base_addr;
+extern phys_addr_t sysram_base_phys;
 extern void __iomem *pmu_base_addr;
 void exynos_sysram_init(void);
 

arch/arm/mach-exynos/exynos.c

@@ -33,6 +33,7 @@ static struct platform_device exynos_cpuidle = {
 };
 
 void __iomem *sysram_base_addr __ro_after_init;
+phys_addr_t sysram_base_phys __ro_after_init;
 void __iomem *sysram_ns_base_addr __ro_after_init;
 
 void __init exynos_sysram_init(void)
@@ -43,6 +44,8 @@ void __init exynos_sysram_init(void)
 		if (!of_device_is_available(node))
 			continue;
 		sysram_base_addr = of_iomap(node, 0);
+		sysram_base_phys = of_translate_address(node,
+					   of_get_address(node, 0, NULL, NULL));
 		break;
 	}
 

arch/arm/mach-exynos/suspend.c

@@ -31,6 +31,7 @@
 #include <asm/suspend.h>
 
 #include "common.h"
+#include "smc.h"
 
 #define REG_TABLE_END (-1U)
 
@@ -62,6 +63,8 @@ struct exynos_pm_state {
 	int cpu_state;
 	unsigned int pmu_spare3;
 	void __iomem *sysram_base;
+	phys_addr_t sysram_phys;
+	bool secure_firmware;
 };
 
 static const struct exynos_pm_data *pm_data __ro_after_init;
@@ -340,6 +343,10 @@ static void exynos5420_pm_prepare(void)
 	pm_state.cpu_state = readl_relaxed(pm_state.sysram_base +
 					   EXYNOS5420_CPU_STATE);
 	writel_relaxed(0x0, pm_state.sysram_base + EXYNOS5420_CPU_STATE);
+	if (pm_state.secure_firmware)
+		exynos_smc(SMC_CMD_REG, SMC_REG_ID_SFR_W(pm_state.sysram_phys +
+							 EXYNOS5420_CPU_STATE),
+			   0, 0);
 
 	exynos_pm_enter_sleep_mode();
 
@@ -459,6 +466,11 @@ static void exynos5420_pm_resume(void)
 	/* Restore the sysram cpu state register */
 	writel_relaxed(pm_state.cpu_state,
 		       pm_state.sysram_base + EXYNOS5420_CPU_STATE);
+	if (pm_state.secure_firmware)
+		exynos_smc(SMC_CMD_REG,
+			   SMC_REG_ID_SFR_W(pm_state.sysram_phys +
+					    EXYNOS5420_CPU_STATE),
+			   EXYNOS_AFTR_MAGIC, 0);
 
 	pmu_raw_writel(EXYNOS5420_USE_STANDBY_WFI_ALL,
 			S5P_CENTRAL_SEQ_OPTION);
@@ -658,8 +670,11 @@ void __init exynos_pm_init(void)
 	 * Applicable as of now only to Exynos542x. If booted under secure
 	 * firmware, the non-secure region of sysram should be used.
 	 */
-	if (exynos_secure_firmware_available())
+	if (exynos_secure_firmware_available()) {
+		pm_state.sysram_phys = sysram_base_phys;
 		pm_state.sysram_base = sysram_ns_base_addr;
-	else
+		pm_state.secure_firmware = true;
+	} else {
 		pm_state.sysram_base = sysram_base_addr;
+	}
 }