--- /dev/null
+/*
+ * linux/arch/arm/kernel/devtree.c
+ *
+ * Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/smp.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>
+
+
+#ifdef CONFIG_SMP
+extern struct of_cpu_method __cpu_method_of_table[];
+
+static const struct of_cpu_method __cpu_method_of_table_sentinel
+ __used __section(__cpu_method_of_table_end);
+
+
+static int __init set_smp_ops_by_method(struct device_node *node)
+{
+ const char *method;
+ struct of_cpu_method *m = __cpu_method_of_table;
+
+ if (of_property_read_string(node, "enable-method", &method))
+ return 0;
+
+ for (; m->method; m++)
+ if (!strcmp(m->method, method)) {
+ smp_set_ops(m->ops);
+ return 1;
+ }
+
+ return 0;
+}
+#else
+static inline int set_smp_ops_by_method(struct device_node *node)
+{
+ return 1;
+}
+#endif
+
+
+/*
+ * 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;
+ int found_method = 0;
+ 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] = MPIDR_INVALID };
+ bool bootcpu_valid = false;
+ cpus = of_find_node_by_path("/cpus");
+
+ if (!cpus)
+ return;
+
+ for_each_child_of_node(cpus, cpu) {
+ u32 hwid;
+
+ if (of_node_cmp(cpu->type, "cpu"))
+ continue;
+
+ 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++;
+ }
+
+ if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than "
+ "max cores %u, capping them\n",
+ cpuidx, nr_cpu_ids)) {
+ cpuidx = nr_cpu_ids;
+ break;
+ }
+
+ tmp_map[i] = hwid;
+
+ if (!found_method)
+ found_method = set_smp_ops_by_method(cpu);
+ }
+
+ /*
+ * Fallback to an enable-method in the cpus node if nothing found in
+ * a cpu node.
+ */
+ if (!found_method)
+ set_smp_ops_by_method(cpus);
+
+ if (!bootcpu_valid) {
+ pr_warn("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));
+ }
+}
+
+bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+ return phys_id == cpu_logical_map(cpu);
+}
+
+static const void * __init arch_get_next_mach(const char *const **match)
+{
+ static const struct machine_desc *mdesc = __arch_info_begin;
+ const struct machine_desc *m = mdesc;
+
+ if (m >= __arch_info_end)
+ return NULL;
+
+ mdesc++;
+ *match = m->dt_compat;
+ return m;
+}
+
+/**
+ * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
+ * @dt_phys: physical address of dt blob
+ *
+ * If a dtb was passed to the kernel in r2, then use it to choose the
+ * correct machine_desc and to setup the system.
+ */
+const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
+{
+ const struct machine_desc *mdesc, *mdesc_best = NULL;
+
+#ifdef CONFIG_ARCH_MULTIPLATFORM
+ DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
+ MACHINE_END
+
+ mdesc_best = &__mach_desc_GENERIC_DT;
+#endif
+
+ if (!dt_phys || !early_init_dt_verify(phys_to_virt(dt_phys)))
+ return NULL;
+
+ mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
+
+ if (!mdesc) {
+ const char *prop;
+ int size;
+ unsigned long dt_root;
+
+ early_print("\nError: unrecognized/unsupported "
+ "device tree compatible list:\n[ ");
+
+ dt_root = of_get_flat_dt_root();
+ prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
+ while (size > 0) {
+ early_print("'%s' ", prop);
+ size -= strlen(prop) + 1;
+ prop += strlen(prop) + 1;
+ }
+ early_print("]\n\n");
+
+ dump_machine_table(); /* does not return */
+ }
+
+ /* We really don't want to do this, but sometimes firmware provides buggy data */
+ if (mdesc->dt_fixup)
+ mdesc->dt_fixup();
+
+ early_init_dt_scan_nodes();
+
+ /* Change machine number to match the mdesc we're using */
+ __machine_arch_type = mdesc->nr;
+
+ return mdesc;
+}
Code Review / kvmfornfv.git / blobdiff