ARM: qcom: Re-organize platsmp to make it extensible

This makes it easy to add SMP support for new devices by keying
on a device node for the release sequence. We add the
enable-method property for the cpus property to specify that we
want to use the gcc-msm8660 release sequence (which is going to
look for the global clock controller device node to map some
Scorpion specific power and control registers). We also remove
the nr_cpus detection code as that is done generically in the DT
CPU detection code.

Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
[sboyd: Port to CPU_METHOD_OF_DECLARE]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Kumar Gala <galak@codeaurora.org>

arch/arm/mach-msm/common.h

@@ -23,8 +23,6 @@ extern void msm_map_qsd8x50_io(void);
 extern void __iomem *__msm_ioremap_caller(phys_addr_t phys_addr, size_t size,
 					  unsigned int mtype, void *caller);
 
-extern struct smp_operations msm_smp_ops;
-
 struct msm_mmc_platform_data;
 
 extern void msm_add_devices(void);

arch/arm/mach-qcom/board.c

@@ -11,30 +11,16 @@
  */
 
 #include <linux/init.h>
-#include <linux/of.h>
-#include <linux/of_platform.h>
 
 #include <asm/mach/arch.h>
-#include <asm/mach/map.h>
-
-extern struct smp_operations qcom_smp_ops;
 
 static const char * const qcom_dt_match[] __initconst = {
 	"qcom,msm8660-surf",
 	"qcom,msm8960-cdp",
-	NULL
-};
-
-static const char * const apq8074_dt_match[] __initconst = {
 	"qcom,apq8074-dragonboard",
 	NULL
 };
 
 DT_MACHINE_START(QCOM_DT, "Qualcomm (Flattened Device Tree)")
-	.smp = smp_ops(qcom_smp_ops),
 	.dt_compat = qcom_dt_match,
 MACHINE_END
-
-DT_MACHINE_START(APQ_DT, "Qualcomm (Flattened Device Tree)")
-	.dt_compat = apq8074_dt_match,
-MACHINE_END

arch/arm/mach-qcom/platsmp.c

@@ -13,17 +13,18 @@
 #include <linux/errno.h>
 #include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/smp.h>
 #include <linux/io.h>
 
-#include <asm/cputype.h>
 #include <asm/smp_plat.h>
 
 #include "scm-boot.h"
 
-#define VDD_SC1_ARRAY_CLAMP_GFS_CTL 0x15A0
-#define SCSS_CPU1CORE_RESET 0xD80
-#define SCSS_DBG_STATUS_CORE_PWRDUP 0xE64
+#define VDD_SC1_ARRAY_CLAMP_GFS_CTL	0x35a0
+#define SCSS_CPU1CORE_RESET		0x2d80
+#define SCSS_DBG_STATUS_CORE_PWRDUP	0x2e64
 
 extern void secondary_startup(void);
 
@@ -36,12 +37,6 @@ static void __ref qcom_cpu_die(unsigned int cpu)
 }
 #endif
 
-static inline int get_core_count(void)
-{
-	/* 1 + the PART[1:0] field of MIDR */
-	return ((read_cpuid_id() >> 4) & 3) + 1;
-}
-
 static void qcom_secondary_init(unsigned int cpu)
 {
 	/*
@@ -51,33 +46,41 @@ static void qcom_secondary_init(unsigned int cpu)
 	spin_unlock(&boot_lock);
 }
 
-static void prepare_cold_cpu(unsigned int cpu)
+static int scss_release_secondary(unsigned int cpu)
 {
-	int ret;
-	ret = scm_set_boot_addr(virt_to_phys(secondary_startup),
-				SCM_FLAG_COLDBOOT_CPU1);
-	if (ret == 0) {
-		void __iomem *sc1_base_ptr;
-		sc1_base_ptr = ioremap_nocache(0x00902000, SZ_4K*2);
-		if (sc1_base_ptr) {
-			writel(0, sc1_base_ptr + VDD_SC1_ARRAY_CLAMP_GFS_CTL);
-			writel(0, sc1_base_ptr + SCSS_CPU1CORE_RESET);
-			writel(3, sc1_base_ptr + SCSS_DBG_STATUS_CORE_PWRDUP);
-			iounmap(sc1_base_ptr);
-		}
-	} else
-		printk(KERN_DEBUG "Failed to set secondary core boot "
-				  "address\n");
+	struct device_node *node;
+	void __iomem *base;
+
+	node = of_find_compatible_node(NULL, NULL, "qcom,gcc-msm8660");
+	if (!node) {
+		pr_err("%s: can't find node\n", __func__);
+		return -ENXIO;
+	}
+
+	base = of_iomap(node, 0);
+	of_node_put(node);
+	if (!base)
+		return -ENOMEM;
+
+	writel_relaxed(0, base + VDD_SC1_ARRAY_CLAMP_GFS_CTL);
+	writel_relaxed(0, base + SCSS_CPU1CORE_RESET);
+	writel_relaxed(3, base + SCSS_DBG_STATUS_CORE_PWRDUP);
+	mb();
+	iounmap(base);
+
+	return 0;
 }
 
-static int qcom_boot_secondary(unsigned int cpu, struct task_struct *idle)
+static DEFINE_PER_CPU(int, cold_boot_done);
+
+static int qcom_boot_secondary(unsigned int cpu, int (*func)(unsigned int))
 {
-	static int cold_boot_done;
+	int ret = 0;
 
-	/* Only need to bring cpu out of reset this way once */
-	if (cold_boot_done == false) {
-		prepare_cold_cpu(cpu);
-		cold_boot_done = true;
+	if (!per_cpu(cold_boot_done, cpu)) {
+		ret = func(cpu);
+		if (!ret)
+			per_cpu(cold_boot_done, cpu) = true;
 	}
 
 	/*
@@ -99,39 +102,48 @@ static int qcom_boot_secondary(unsigned int cpu, struct task_struct *idle)
 	 */
 	spin_unlock(&boot_lock);
 
-	return 0;
+	return ret;
 }
 
-/*
- * Initialise the CPU possible map early - this describes the CPUs
- * which may be present or become present in the system. The msm8x60
- * does not support the ARM SCU, so just set the possible cpu mask to
- * NR_CPUS.
- */
-static void __init qcom_smp_init_cpus(void)
+static int msm8660_boot_secondary(unsigned int cpu, struct task_struct *idle)
 {
-	unsigned int i, ncores = get_core_count();
-
-	if (ncores > nr_cpu_ids) {
-		pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
-			ncores, nr_cpu_ids);
-		ncores = nr_cpu_ids;
-	}
-
-	for (i = 0; i < ncores; i++)
-		set_cpu_possible(i, true);
+	return qcom_boot_secondary(cpu, scss_release_secondary);
 }
 
 static void __init qcom_smp_prepare_cpus(unsigned int max_cpus)
 {
+	int cpu, map;
+	unsigned int flags = 0;
+	static const int cold_boot_flags[] = {
+		0,
+		SCM_FLAG_COLDBOOT_CPU1,
+	};
+
+	for_each_present_cpu(cpu) {
+		map = cpu_logical_map(cpu);
+		if (WARN_ON(map >= ARRAY_SIZE(cold_boot_flags))) {
+			set_cpu_present(cpu, false);
+			continue;
+		}
+		flags |= cold_boot_flags[map];
+	}
+
+	if (scm_set_boot_addr(virt_to_phys(secondary_startup), flags)) {
+		for_each_present_cpu(cpu) {
+			if (cpu == smp_processor_id())
+				continue;
+			set_cpu_present(cpu, false);
+		}
+		pr_warn("Failed to set CPU boot address, disabling SMP\n");
+	}
 }
 
-struct smp_operations qcom_smp_ops __initdata = {
-	.smp_init_cpus		= qcom_smp_init_cpus,
+static struct smp_operations smp_msm8660_ops __initdata = {
 	.smp_prepare_cpus	= qcom_smp_prepare_cpus,
 	.smp_secondary_init	= qcom_secondary_init,
-	.smp_boot_secondary	= qcom_boot_secondary,
+	.smp_boot_secondary	= msm8660_boot_secondary,
 #ifdef CONFIG_HOTPLUG_CPU
 	.cpu_die		= qcom_cpu_die,
 #endif
 };
+CPU_METHOD_OF_DECLARE(qcom_smp, "qcom,gcc-msm8660", &smp_msm8660_ops);