Merge branch 'cluster-boot-protocol' of git://linux-arm.org/linux-2.6…

…-lp into devel-stable

Documentation/devicetree/bindings/arm/cpus.txt

@@ -0,0 +1,77 @@
+* ARM CPUs binding description
+
+The device tree allows to describe the layout of CPUs in a system through
+the "cpus" node, which in turn contains a number of subnodes (ie "cpu")
+defining properties for every cpu.
+
+Bindings for CPU nodes follow the ePAPR standard, available from:
+
+http://devicetree.org
+
+For the ARM architecture every CPU node must contain the following properties:
+
+- device_type:	must be "cpu"
+- reg:		property matching the CPU MPIDR[23:0] register bits
+		reg[31:24] bits must be set to 0
+- compatible:	should be one of:
+		"arm,arm1020"
+		"arm,arm1020e"
+		"arm,arm1022"
+		"arm,arm1026"
+		"arm,arm720"
+		"arm,arm740"
+		"arm,arm7tdmi"
+		"arm,arm920"
+		"arm,arm922"
+		"arm,arm925"
+		"arm,arm926"
+		"arm,arm940"
+		"arm,arm946"
+		"arm,arm9tdmi"
+		"arm,cortex-a5"
+		"arm,cortex-a7"
+		"arm,cortex-a8"
+		"arm,cortex-a9"
+		"arm,cortex-a15"
+		"arm,arm1136"
+		"arm,arm1156"
+		"arm,arm1176"
+		"arm,arm11mpcore"
+		"faraday,fa526"
+		"intel,sa110"
+		"intel,sa1100"
+		"marvell,feroceon"
+		"marvell,mohawk"
+		"marvell,xsc3"
+		"marvell,xscale"
+
+Example:
+
+	cpus {
+		#size-cells = <0>;
+		#address-cells = <1>;
+
+		CPU0: cpu@0 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a15";
+			reg = <0x0>;
+		};
+
+		CPU1: cpu@1 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a15";
+			reg = <0x1>;
+		};
+
+		CPU2: cpu@100 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a7";
+			reg = <0x100>;
+		};
+
+		CPU3: cpu@101 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a7";
+			reg = <0x101>;
+		};
+	};

arch/arm/common/gic.c

@@ -69,6 +69,14 @@ struct gic_chip_data {
 
 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
 
+/*
+ * The GIC mapping of CPU interfaces does not necessarily match
+ * the logical CPU numbering.  Let's use a mapping as returned
+ * by the GIC itself.
+ */
+#define NR_GIC_CPU_IF 8
+static u8 gic_cpu_map[NR_GIC_CPU_IF] __read_mostly;
+
 /*
  * Supported arch specific GIC irq extension.
  * Default make them NULL.
@@ -238,11 +246,11 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
 	unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
 	u32 val, mask, bit;
 
-	if (cpu >= 8 || cpu >= nr_cpu_ids)
+	if (cpu >= NR_GIC_CPU_IF || cpu >= nr_cpu_ids)
 		return -EINVAL;
 
 	mask = 0xff << shift;
-	bit = 1 << (cpu_logical_map(cpu) + shift);
+	bit = gic_cpu_map[cpu] << shift;
 
 	raw_spin_lock(&irq_controller_lock);
 	val = readl_relaxed(reg) & ~mask;
@@ -349,11 +357,6 @@ static void __init gic_dist_init(struct gic_chip_data *gic)
 	u32 cpumask;
 	unsigned int gic_irqs = gic->gic_irqs;
 	void __iomem *base = gic_data_dist_base(gic);
-	u32 cpu = cpu_logical_map(smp_processor_id());
-
-	cpumask = 1 << cpu;
-	cpumask |= cpumask << 8;
-	cpumask |= cpumask << 16;
 
 	writel_relaxed(0, base + GIC_DIST_CTRL);
 
@@ -366,6 +369,7 @@ static void __init gic_dist_init(struct gic_chip_data *gic)
 	/*
 	 * Set all global interrupts to this CPU only.
 	 */
+	cpumask = readl_relaxed(base + GIC_DIST_TARGET + 0);
 	for (i = 32; i < gic_irqs; i += 4)
 		writel_relaxed(cpumask, base + GIC_DIST_TARGET + i * 4 / 4);
 
@@ -389,8 +393,24 @@ static void __cpuinit gic_cpu_init(struct gic_chip_data *gic)
 {
 	void __iomem *dist_base = gic_data_dist_base(gic);
 	void __iomem *base = gic_data_cpu_base(gic);
+	unsigned int cpu_mask, cpu = smp_processor_id();
 	int i;
 
+	/*
+	 * Get what the GIC says our CPU mask is.
+	 */
+	BUG_ON(cpu >= NR_GIC_CPU_IF);
+	cpu_mask = readl_relaxed(dist_base + GIC_DIST_TARGET + 0);
+	gic_cpu_map[cpu] = cpu_mask;
+
+	/*
+	 * Clear our mask from the other map entries in case they're
+	 * still undefined.
+	 */
+	for (i = 0; i < NR_GIC_CPU_IF; i++)
+		if (i != cpu)
+			gic_cpu_map[i] &= ~cpu_mask;
+
 	/*
 	 * Deal with the banked PPI and SGI interrupts - disable all
 	 * PPI interrupts, ensure all SGI interrupts are enabled.
@@ -646,7 +666,7 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
 {
 	irq_hw_number_t hwirq_base;
 	struct gic_chip_data *gic;
-	int gic_irqs, irq_base;
+	int gic_irqs, irq_base, i;
 
 	BUG_ON(gic_nr >= MAX_GIC_NR);
 
@@ -682,6 +702,13 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
 		gic_set_base_accessor(gic, gic_get_common_base);
 	}
 
+	/*
+	 * Initialize the CPU interface map to all CPUs.
+	 * It will be refined as each CPU probes its ID.
+	 */
+	for (i = 0; i < NR_GIC_CPU_IF; i++)
+		gic_cpu_map[i] = 0xff;
+
 	/*
 	 * For primary GICs, skip over SGIs.
 	 * For secondary GICs, skip over PPIs, too.
@@ -737,7 +764,7 @@ void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
 
 	/* Convert our logical CPU mask into a physical one. */
 	for_each_cpu(cpu, mask)
-		map |= 1 << cpu_logical_map(cpu);
+		map |= gic_cpu_map[cpu];
 
 	/*
 	 * Ensure that stores to Normal memory are visible to the

arch/arm/include/asm/cputype.h

@@ -25,6 +25,19 @@
 #define CPUID_EXT_ISAR4	"c2, 4"
 #define CPUID_EXT_ISAR5	"c2, 5"
 
+#define MPIDR_SMP_BITMASK (0x3 << 30)
+#define MPIDR_SMP_VALUE (0x2 << 30)
+
+#define MPIDR_MT_BITMASK (0x1 << 24)
+
+#define MPIDR_HWID_BITMASK 0xFFFFFF
+
+#define MPIDR_LEVEL_BITS 8
+#define MPIDR_LEVEL_MASK ((1 << MPIDR_LEVEL_BITS) - 1)
+
+#define MPIDR_AFFINITY_LEVEL(mpidr, level) \
+	((mpidr >> (MPIDR_LEVEL_BITS * level)) & MPIDR_LEVEL_MASK)
+
 extern unsigned int processor_id;
 
 #ifdef CONFIG_CPU_CP15

arch/arm/include/asm/prom.h

@@ -15,6 +15,7 @@
 
 extern struct machine_desc *setup_machine_fdt(unsigned int dt_phys);
 extern void arm_dt_memblock_reserve(void);
+extern void __init arm_dt_init_cpu_maps(void);
 
 #else /* CONFIG_OF */
 
@@ -24,6 +25,7 @@ static inline struct machine_desc *setup_machine_fdt(unsigned int dt_phys)
 }
 
 static inline void arm_dt_memblock_reserve(void) { }
+static inline void arm_dt_init_cpu_maps(void) { }
 
 #endif /* CONFIG_OF */
 #endif /* ASMARM_PROM_H */

arch/arm/include/asm/smp_plat.h

@@ -5,6 +5,9 @@
 #ifndef __ASMARM_SMP_PLAT_H
 #define __ASMARM_SMP_PLAT_H
 
+#include <linux/cpumask.h>
+#include <linux/err.h>
+
 #include <asm/cputype.h>
 
 /*
@@ -48,5 +51,19 @@ static inline int cache_ops_need_broadcast(void)
  */
 extern int __cpu_logical_map[];
 #define cpu_logical_map(cpu)	__cpu_logical_map[cpu]
+/*
+ * Retrieve logical cpu index corresponding to a given MPIDR[23:0]
+ *  - mpidr: MPIDR[23:0] to be used for the look-up
+ *
+ * Returns the cpu logical index or -EINVAL on look-up error
+ */
+static inline int get_logical_index(u32 mpidr)
+{
+	int cpu;
+	for (cpu = 0; cpu < nr_cpu_ids; cpu++)
+		if (cpu_logical_map(cpu) == mpidr)
+			return cpu;
+	return -EINVAL;
+}
 
 #endif

arch/arm/kernel/devtree.c

@@ -19,8 +19,10 @@
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 
+#include <asm/cputype.h>
 #include <asm/setup.h>
 #include <asm/page.h>
+#include <asm/smp_plat.h>
 #include <asm/mach/arch.h>
 #include <asm/mach-types.h>
 
@@ -61,6 +63,104 @@ void __init arm_dt_memblock_reserve(void)
 	}
 }
 
+/*
+ * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree
+ * and builds the cpu logical map array containing MPIDR values related to
+ * logical cpus
+ *
+ * Updates the cpu possible mask with the number of parsed cpu nodes
+ */
+void __init arm_dt_init_cpu_maps(void)
+{
+	/*
+	 * Temp logical map is initialized with UINT_MAX values that are
+	 * considered invalid logical map entries since the logical map must
+	 * contain a list of MPIDR[23:0] values where MPIDR[31:24] must
+	 * read as 0.
+	 */
+	struct device_node *cpu, *cpus;
+	u32 i, j, cpuidx = 1;
+	u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
+
+	u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = UINT_MAX };
+	bool bootcpu_valid = false;
+	cpus = of_find_node_by_path("/cpus");
+
+	if (!cpus)
+		return;
+
+	for_each_child_of_node(cpus, cpu) {
+		u32 hwid;
+
+		pr_debug(" * %s...\n", cpu->full_name);
+		/*
+		 * A device tree containing CPU nodes with missing "reg"
+		 * properties is considered invalid to build the
+		 * cpu_logical_map.
+		 */
+		if (of_property_read_u32(cpu, "reg", &hwid)) {
+			pr_debug(" * %s missing reg property\n",
+				     cpu->full_name);
+			return;
+		}
+
+		/*
+		 * 8 MSBs must be set to 0 in the DT since the reg property
+		 * defines the MPIDR[23:0].
+		 */
+		if (hwid & ~MPIDR_HWID_BITMASK)
+			return;
+
+		/*
+		 * Duplicate MPIDRs are a recipe for disaster.
+		 * Scan all initialized entries and check for
+		 * duplicates. If any is found just bail out.
+		 * temp values were initialized to UINT_MAX
+		 * to avoid matching valid MPIDR[23:0] values.
+		 */
+		for (j = 0; j < cpuidx; j++)
+			if (WARN(tmp_map[j] == hwid, "Duplicate /cpu reg "
+						     "properties in the DT\n"))
+				return;
+
+		/*
+		 * Build a stashed array of MPIDR values. Numbering scheme
+		 * requires that if detected the boot CPU must be assigned
+		 * logical id 0. Other CPUs get sequential indexes starting
+		 * from 1. If a CPU node with a reg property matching the
+		 * boot CPU MPIDR is detected, this is recorded so that the
+		 * logical map built from DT is validated and can be used
+		 * to override the map created in smp_setup_processor_id().
+		 */
+		if (hwid == mpidr) {
+			i = 0;
+			bootcpu_valid = true;
+		} else {
+			i = cpuidx++;
+		}
+
+		tmp_map[i] = hwid;
+
+		if (cpuidx > nr_cpu_ids)
+			break;
+	}
+
+	if (WARN(!bootcpu_valid, "DT missing boot CPU MPIDR[23:0], "
+				 "fall back to default cpu_logical_map\n"))
+		return;
+
+	/*
+	 * Since the boot CPU node contains proper data, and all nodes have
+	 * a reg property, the DT CPU list can be considered valid and the
+	 * logical map created in smp_setup_processor_id() can be overridden
+	 */
+	for (i = 0; i < cpuidx; i++) {
+		set_cpu_possible(i, true);
+		cpu_logical_map(i) = tmp_map[i];
+		pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i));
+	}
+}
+
 /**
  * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
  * @dt_phys: physical address of dt blob

arch/arm/kernel/setup.c

@@ -426,13 +426,14 @@ int __cpu_logical_map[NR_CPUS];
 void __init smp_setup_processor_id(void)
 {
 	int i;
-	u32 cpu = is_smp() ? read_cpuid_mpidr() & 0xff : 0;
+	u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
+	u32 cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 
 	cpu_logical_map(0) = cpu;
-	for (i = 1; i < NR_CPUS; ++i)
+	for (i = 1; i < nr_cpu_ids; ++i)
 		cpu_logical_map(i) = i == cpu ? 0 : i;
 
-	printk(KERN_INFO "Booting Linux on physical CPU %d\n", cpu);
+	printk(KERN_INFO "Booting Linux on physical CPU 0x%x\n", mpidr);
 }
 
 static void __init setup_processor(void)
@@ -758,6 +759,7 @@ void __init setup_arch(char **cmdline_p)
 
 	unflatten_device_tree();
 
+	arm_dt_init_cpu_maps();
 #ifdef CONFIG_SMP
 	if (is_smp()) {
 		smp_set_ops(mdesc->smp);