| /* |
| * 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/prom.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); |
| of_node_put(cpu); |
| 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) { |
| of_node_put(cpu); |
| 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")) { |
| of_node_put(cpu); |
| 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; |
| of_node_put(cpu); |
| 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; |
| |
| #if defined(CONFIG_ARCH_MULTIPLATFORM) || defined(CONFIG_ARM_SINGLE_ARMV7M) |
| DT_MACHINE_START(GENERIC_DT, "Generic DT based system") |
| .l2c_aux_val = 0x0, |
| .l2c_aux_mask = ~0x0, |
| 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; |
| } |