Get kexec working on SMP omap variants

index f7666b9..9cbae6e 100644
@@ -257,6 +257,7 @@ extern void gic_dist_enable(void);
 extern bool gic_dist_disabled(void);
 extern void gic_timer_retrigger(void);
 extern void omap_smc1(u32 fn, u32 arg);
+extern void omap4_sar_ram_init(void);
 extern void __iomem *omap4_get_sar_ram_base(void);
 extern void omap_do_wfi(void);
 

index 49de4dd..4548cb9 100644
@@ -690,6 +690,7 @@ void __init omap4430_init_early(void)
 	omap4xxx_check_revision();
 	omap4xxx_check_features();
 	omap2_prcm_base_init();
+	omap4_sar_ram_init();
 	omap4_pm_init_early();
 	omap44xx_voltagedomains_init();
 	omap44xx_powerdomains_init();

@@ -718,6 +719,7 @@ void __init omap5_init_early(void)
 	omap4_pm_init_early();
 	omap2_prcm_base_init();
 	omap5xxx_check_revision();
+	omap4_sar_ram_init();
 	omap54xx_voltagedomains_init();
 	omap54xx_powerdomains_init();
 	omap54xx_clockdomains_init();

index fb6fe26..cf65ab8 100644
@@ -266,10 +266,11 @@ void __iomem *omap4_get_sar_ram_base(void)
 }
 
 /*
- * SAR RAM used to save and restore the HW
- * context in low power modes
+ * SAR RAM used to save and restore the HW context in low power modes.
+ * Note that we need to initialize this very early for kexec. See
+ * omap4_mpuss_early_init().
  */
-static int __init omap4_sar_ram_init(void)
+void __init omap4_sar_ram_init(void)
 {
 	unsigned long sar_base;
 

@@ -282,16 +283,13 @@ static int __init omap4_sar_ram_init(void)
 	else if (soc_is_omap54xx())
 		sar_base = OMAP54XX_SAR_RAM_BASE;
 	else
-		return -ENOMEM;
+		return;
 
 	/* Static mapping, never released */
 	sar_ram_base = ioremap(sar_base, SZ_16K);
 	if (WARN_ON(!sar_ram_base))
-		return -ENOMEM;
-
-	return 0;
+		return;
 }
-omap_early_initcall(omap4_sar_ram_init);
 
 static const struct of_device_id intc_match[] = {
 	{ .compatible = "ti,omap4-wugen-mpu", },

index 9cbae6e..0136405 100644
@@ -259,12 +259,14 @@ extern void gic_timer_retrigger(void);
 extern void omap_smc1(u32 fn, u32 arg);
 extern void omap4_sar_ram_init(void);
 extern void __iomem *omap4_get_sar_ram_base(void);
+extern void omap4_mpuss_early_init(void);
 extern void omap_do_wfi(void);
 
-#ifdef CONFIG_SMP
-/* Needed for secondary core boot */
 extern void omap4_secondary_startup(void);
 extern void omap4460_secondary_startup(void);
+
+#ifdef CONFIG_SMP
+/* Needed for secondary core boot */
 extern u32 omap_modify_auxcoreboot0(u32 set_mask, u32 clear_mask);
 extern void omap_auxcoreboot_addr(u32 cpu_addr);
 extern u32 omap_read_auxcoreboot0(void);

index 4548cb9..0e9acdd 100644
@@ -691,6 +691,7 @@ void __init omap4430_init_early(void)
 	omap4xxx_check_features();
 	omap2_prcm_base_init();
 	omap4_sar_ram_init();
+	omap4_mpuss_early_init();
 	omap4_pm_init_early();
 	omap44xx_voltagedomains_init();
 	omap44xx_powerdomains_init();

index 65024af..1751517 100644
@@ -62,6 +62,8 @@
 #include "prm44xx.h"
 #include "prm-regbits-44xx.h"
 
+static void __iomem *sar_base;
+
 #ifdef CONFIG_SMP
 
 struct omap4_cpu_pm_info {

@@ -90,7 +92,6 @@ struct cpu_pm_ops {
 
 static DEFINE_PER_CPU(struct omap4_cpu_pm_info, omap4_pm_info);
 static struct powerdomain *mpuss_pd;
-static void __iomem *sar_base;
 static u32 cpu_context_offset;
 
 static int default_finish_suspend(unsigned long cpu_state)

@@ -366,9 +367,6 @@ int __init omap4_mpuss_init(void)
 		return -ENODEV;
 	}
 
-	if (cpu_is_omap44xx())
-		sar_base = omap4_get_sar_ram_base();
-
 	/* Initilaise per CPU PM information */
 	pm_info = &per_cpu(omap4_pm_info, 0x0);
 	if (sar_base) {

@@ -444,3 +442,26 @@ int __init omap4_mpuss_init(void)
 }
 
 #endif
+
+/*
+ * For kexec, we must set CPU1_WAKEUP_NS_PA_ADDR to point to
+ * current kernel's secondary_startup() early before
+ * clockdomains_init(). Otherwise clockdomain_init() can
+ * wake CPU1 and cause a hang.
+ */
+void __init omap4_mpuss_early_init(void)
+{
+	unsigned long startup_pa;
+
+	if (!cpu_is_omap44xx())
+		return;
+
+	sar_base = omap4_get_sar_ram_base();
+
+	if (cpu_is_omap443x())
+		startup_pa = virt_to_phys(omap4_secondary_startup);
+	else
+		startup_pa = virt_to_phys(omap4460_secondary_startup);
+
+	writel_relaxed(startup_pa, sar_base + CPU1_WAKEUP_NS_PA_ADDR_OFFSET);
+}

index 8cd1de9..81bb053 100644
@@ -40,14 +40,35 @@
 
 #define OMAP5_CORE_COUNT	0x2
 
-/* SCU base address */
-static void __iomem *scu_base;
+struct omap_smp_config {
+	unsigned long cpu1_rstctrl_pa;
+	void __iomem *cpu1_rstctrl_va;
+	void __iomem *scu_base;
+	void *startup_addr;
+};
+
+static struct omap_smp_config cfg;
+
+static const struct omap_smp_config omap443x_cfg __initconst = {
+	.cpu1_rstctrl_pa = 0x4824380c,
+	.startup_addr = omap4_secondary_startup,
+};
+
+static const struct omap_smp_config omap446x_cfg __initconst = {
+	.cpu1_rstctrl_pa = 0x4824380c,
+	.startup_addr = omap4460_secondary_startup,
+};
+
+static const struct omap_smp_config omap5_cfg __initconst = {
+	.cpu1_rstctrl_pa = 0x48243810,
+	.startup_addr = omap5_secondary_startup,
+};
 
 static DEFINE_SPINLOCK(boot_lock);
 
 void __iomem *omap4_get_scu_base(void)
 {
-	return scu_base;
+	return cfg.scu_base;
 }
 
 #ifdef CONFIG_OMAP5_ERRATA_801819

@@ -93,7 +114,7 @@ static void omap4_secondary_init(unsigned int cpu)
 	 * OMAP443X GP devices- SMP bit isn't accessible.
 	 * OMAP446X GP devices - SMP bit access is enabled on both CPUs.
 	 */
-	if (cpu_is_omap443x() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
+	if (soc_is_omap443x() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
 		omap_secure_dispatcher(OMAP4_PPA_CPU_ACTRL_SMP_INDEX,
 							4, 0, 0, 0, 0, 0);
 

@@ -222,9 +243,9 @@ static void __init omap4_smp_init_cpus(void)
 		 * Currently we can't call ioremap here because
 		 * SoC detection won't work until after init_early.
 		 */
-		scu_base =  OMAP2_L4_IO_ADDRESS(scu_a9_get_base());
-		BUG_ON(!scu_base);
-		ncores = scu_get_core_count(scu_base);
+		cfg.scu_base =  OMAP2_L4_IO_ADDRESS(scu_a9_get_base());
+		BUG_ON(!cfg.scu_base);
+		ncores = scu_get_core_count(cfg.scu_base);
 	} else if (cpu_id == CPU_CORTEX_A15) {
 		ncores = OMAP5_CORE_COUNT;
 	}

@@ -242,20 +263,51 @@ static void __init omap4_smp_init_cpus(void)
 
 static void __init omap4_smp_prepare_cpus(unsigned int max_cpus)
 {
-	void *startup_addr = omap4_secondary_startup;
 	void __iomem *base = omap_get_wakeupgen_base();
+	const struct omap_smp_config *c = NULL;
+
+	if (soc_is_omap443x())
+		c = &omap443x_cfg;
+	else if (soc_is_omap446x())
+		c = &omap446x_cfg;
+	else if (soc_is_dra74x() || soc_is_omap54xx())
+		c = &omap5_cfg;
+
+	if (!c) {
+		pr_err("%s Unknown SMP SoC?\n", __func__);
+		return;
+	}
+
+	/* Must preserve cfg.scu_base set earlier */
+	cfg.cpu1_rstctrl_pa = c->cpu1_rstctrl_pa;
+	cfg.startup_addr = c->startup_addr;
+
+	if (soc_is_dra74x() || soc_is_omap54xx()) {
+		if ((__boot_cpu_mode & MODE_MASK) == HYP_MODE)
+			cfg.startup_addr = omap5_secondary_hyp_startup;
+		omap5_erratum_workaround_801819();
+	}
+
+	cfg.cpu1_rstctrl_va = ioremap(cfg.cpu1_rstctrl_pa, 4);
+	if (!cfg.cpu1_rstctrl_va)
+		return;
 
 	/*
 	 * Initialise the SCU and wake up the secondary core using
 	 * wakeup_secondary().
 	 */
-	if (scu_base)
-		scu_enable(scu_base);
+	if (cfg.scu_base)
+		scu_enable(cfg.scu_base);
 
-	if (cpu_is_omap446x())
-		startup_addr = omap4460_secondary_startup;
-	if (soc_is_dra74x() || soc_is_omap54xx())
-		omap5_erratum_workaround_801819();
+	/*
+	 * Reset CPU1 before configuring, otherwise kexec will
+	 * end up trying to use old kernel startup address.
+	 */
+	if (cfg.cpu1_rstctrl_va) {
+		writel_relaxed(1, cfg.cpu1_rstctrl_va);
+		readl_relaxed(cfg.cpu1_rstctrl_va);
+		writel_relaxed(0, cfg.cpu1_rstctrl_va);
+	}
 
 	/*
 	 * Write the address of secondary startup routine into the

@@ -264,19 +316,10 @@ static void __init omap4_smp_prepare_cpus(unsigned int max_cpus)
 	 * A barrier is added to ensure that write buffer is drained
 	 */
 	if (omap_secure_apis_support())
-		omap_auxcoreboot_addr(virt_to_phys(startup_addr));
+		omap_auxcoreboot_addr(virt_to_phys(cfg.startup_addr));
 	else
-		/*
-		 * If the boot CPU is in HYP mode then start secondary
-		 * CPU in HYP mode as well.
-		 */
-		if ((__boot_cpu_mode & MODE_MASK) == HYP_MODE)
-			writel_relaxed(virt_to_phys(omap5_secondary_hyp_startup),
-				       base + OMAP_AUX_CORE_BOOT_1);
-		else
-			writel_relaxed(virt_to_phys(omap5_secondary_startup),
-				       base + OMAP_AUX_CORE_BOOT_1);
-
+		writel_relaxed(virt_to_phys(cfg.startup_addr),
+			       base + OMAP_AUX_CORE_BOOT_1);
 }
 
 const struct smp_operations omap4_smp_ops __initconst = {

index 0136405..deed42e 100644
@@ -272,6 +272,7 @@ extern void omap_auxcoreboot_addr(u32 cpu_addr);
 extern u32 omap_read_auxcoreboot0(void);
 
 extern void omap4_cpu_die(unsigned int cpu);
+extern int omap4_cpu_kill(unsigned int cpu);
 
 extern const struct smp_operations omap4_smp_ops;
 

index 593fec7..d3fb566 100644
@@ -64,3 +64,9 @@ void omap4_cpu_die(unsigned int cpu)
 		pr_debug("CPU%u: spurious wakeup call\n", cpu);
 	}
 }
+
+/* Needed by kexec and platform_can_cpu_hotplug() */
+int omap4_cpu_kill(unsigned int cpu)
+{
+	return 1;
+}

index 81bb053..d53a0de 100644
@@ -329,5 +329,6 @@ const struct smp_operations omap4_smp_ops __initconst = {
 	.smp_boot_secondary	= omap4_boot_secondary,
 #ifdef CONFIG_HOTPLUG_CPU
 	.cpu_die		= omap4_cpu_die,
+	.cpu_kill		= omap4_cpu_kill,
 #endif
 };