[PATCH] ARM: EXYNOS: Restore the entry address setup code post-resume

[Abhilash Kesavan <a.kesavan@samsung.com>]

Setup the mcpm entry address again on system resume as the
iRAM contents are lost across an s2r cycle.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
---
This has been tested after applying the Exynos5420 S2R support series
along with Nicolas Pitre's boot cluster CCI enablement patches on Peach
Pit.

 arch/arm/mach-exynos/mcpm-exynos.c | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c
index 8c610e2..0bf734d 100644
--- a/arch/arm/mach-exynos/mcpm-exynos.c
+++ b/arch/arm/mach-exynos/mcpm-exynos.c
@@ -15,6 +15,7 @@
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/of_address.h>
+#include <linux/syscore_ops.h>
 
 #include <asm/cputype.h>
 #include <asm/cp15.h>
@@ -26,6 +27,7 @@
 #define EXYNOS5420_CPUS_PER_CLUSTER	4
 #define EXYNOS5420_NR_CLUSTERS		2
 
+static void __iomem *ns_sram_base_addr;
 /*
  * The common v7_exit_coherency_flush API could not be used because of the
  * Erratum 799270 workaround. This macro is the same as the common one (in
@@ -308,10 +310,26 @@ static const struct of_device_id exynos_dt_mcpm_match[] = {
 	{},
 };
 
+static void exynos_mcpm_setup_entry_point(void)
+{
+	/*
+	 * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
+	 * as part of secondary_cpu_start().  Let's redirect it to the
+	 * mcpm_entry_point(). This is done during both secondary boot-up as
+	 * well as system resume.
+	 */
+	__raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
+	__raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
+	__raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
+}
+
+static struct syscore_ops exynos_mcpm_syscore_ops = {
+	.resume	= exynos_mcpm_setup_entry_point,
+};
+
 static int __init exynos_mcpm_init(void)
 {
 	struct device_node *node;
-	void __iomem *ns_sram_base_addr;
 	int ret;
 
 	node = of_find_matching_node(NULL, exynos_dt_mcpm_match);
@@ -357,16 +375,9 @@ static int __init exynos_mcpm_init(void)
 
 	pr_info("Exynos MCPM support installed\n");
 
-	/*
-	 * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
-	 * as part of secondary_cpu_start().  Let's redirect it to the
-	 * mcpm_entry_point().
-	 */
-	__raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
-	__raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
-	__raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
+	exynos_mcpm_setup_entry_point();
 
-	iounmap(ns_sram_base_addr);
+	register_syscore_ops(&exynos_mcpm_syscore_ops);
 
 	return ret;
 }
-- 
1.8.3.2