arch/arm/kernel/devtree.c - linux - Git at Google

 /*
  *  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 <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>

 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 {
 	arm_add_memory(base, size);
 }

 void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
 {
 	return alloc_bootmem_align(size, align);
 }

 void __init arm_dt_memblock_reserve(void)
 {
 	u64 *reserve_map, base, size;

 	if (!initial_boot_params)
 		return;

 	/* Reserve the dtb region */
 	memblock_reserve(virt_to_phys(initial_boot_params),
 			 be32_to_cpu(initial_boot_params->totalsize));

 	/*
 	 * Process the reserve map.  This will probably overlap the initrd
 	 * and dtb locations which are already reserved, but overlaping
 	 * doesn't hurt anything
 	 */
 	reserve_map = ((void*)initial_boot_params) +
 			be32_to_cpu(initial_boot_params->off_mem_rsvmap);
 	while (1) {
 		base = be64_to_cpup(reserve_map++);
 		size = be64_to_cpup(reserve_map++);
 		if (!size)
 			break;
 		memblock_reserve(base, size);
 	}
 }

 /*
  * 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] = 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 (!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 & MPIDR_HWID_BITMASK) == cpu_logical_map(cpu);
 }

 /**
  * 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.
  */
 struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
 {
 	struct boot_param_header *devtree;
 	struct machine_desc *mdesc, *mdesc_best = NULL;
 	unsigned int score, mdesc_score = ~1;
 	unsigned long dt_root;
 	const char *model;

 #ifdef CONFIG_ARCH_MULTIPLATFORM
 	DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
 	MACHINE_END

 	mdesc_best = (struct machine_desc *)&__mach_desc_GENERIC_DT;
 #endif

 	if (!dt_phys)
 		return NULL;

 	devtree = phys_to_virt(dt_phys);

 	/* check device tree validity */
 	if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
 		return NULL;

 	/* Search the mdescs for the 'best' compatible value match */
 	initial_boot_params = devtree;
 	dt_root = of_get_flat_dt_root();
 	for_each_machine_desc(mdesc) {
 		score = of_flat_dt_match(dt_root, mdesc->dt_compat);
 		if (score > 0 && score < mdesc_score) {
 			mdesc_best = mdesc;
 			mdesc_score = score;
 		}
 	}
 	if (!mdesc_best) {
 		const char *prop;
 		long size;

 		early_print("\nError: unrecognized/unsupported "
 			    "device tree compatible list:\n[ ");

 		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 */
 	}

 	model = of_get_flat_dt_prop(dt_root, "model", NULL);
 	if (!model)
 		model = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 	if (!model)
 		model = "<unknown>";
 	pr_info("Machine: %s, model: %s\n", mdesc_best->name, model);

 	/* Retrieve various information from the /chosen node */
 	of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
 	/* Initialize {size,address}-cells info */
 	of_scan_flat_dt(early_init_dt_scan_root, NULL);
 	/* Setup memory, calling early_init_dt_add_memory_arch */
 	of_scan_flat_dt(early_init_dt_scan_memory, NULL);

 	/* Change machine number to match the mdesc we're using */
 	__machine_arch_type = mdesc_best->nr;

 	return mdesc_best;
 }
	/*
	* 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 <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>

	void __init early_init_dt_add_memory_arch(u64 base, u64 size)
	{
	arm_add_memory(base, size);
	}

	void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
	{
	return alloc_bootmem_align(size, align);
	}

	void __init arm_dt_memblock_reserve(void)
	{
	u64 *reserve_map, base, size;

	if (!initial_boot_params)
	return;

	/* Reserve the dtb region */
	memblock_reserve(virt_to_phys(initial_boot_params),
	be32_to_cpu(initial_boot_params->totalsize));

	/*
	* Process the reserve map. This will probably overlap the initrd
	* and dtb locations which are already reserved, but overlaping
	* doesn't hurt anything
	*/
	reserve_map = ((void*)initial_boot_params) +
	be32_to_cpu(initial_boot_params->off_mem_rsvmap);
	while (1) {
	base = be64_to_cpup(reserve_map++);
	size = be64_to_cpup(reserve_map++);
	if (!size)
	break;
	memblock_reserve(base, size);
	}
	}

	/*
	* 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] = 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 (!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 & MPIDR_HWID_BITMASK) == cpu_logical_map(cpu);
	}

	/**
	* 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.
	*/
	struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
	{
	struct boot_param_header *devtree;
	struct machine_desc mdesc, mdesc_best = NULL;
	unsigned int score, mdesc_score = ~1;
	unsigned long dt_root;
	const char *model;

	#ifdef CONFIG_ARCH_MULTIPLATFORM
	DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
	MACHINE_END

	mdesc_best = (struct machine_desc *)&__mach_desc_GENERIC_DT;
	#endif

	if (!dt_phys)
	return NULL;

	devtree = phys_to_virt(dt_phys);

	/* check device tree validity */
	if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
	return NULL;

	/* Search the mdescs for the 'best' compatible value match */
	initial_boot_params = devtree;
	dt_root = of_get_flat_dt_root();
	for_each_machine_desc(mdesc) {
	score = of_flat_dt_match(dt_root, mdesc->dt_compat);
	if (score > 0 && score < mdesc_score) {
	mdesc_best = mdesc;
	mdesc_score = score;
	}
	}
	if (!mdesc_best) {
	const char *prop;
	long size;

	early_print("\nError: unrecognized/unsupported "
	"device tree compatible list:\n[ ");

	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 */
	}

	model = of_get_flat_dt_prop(dt_root, "model", NULL);
	if (!model)
	model = of_get_flat_dt_prop(dt_root, "compatible", NULL);
	if (!model)
	model = "<unknown>";
	pr_info("Machine: %s, model: %s\n", mdesc_best->name, model);

	/* Retrieve various information from the /chosen node */
	of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
	/* Initialize {size,address}-cells info */
	of_scan_flat_dt(early_init_dt_scan_root, NULL);
	/* Setup memory, calling early_init_dt_add_memory_arch */
	of_scan_flat_dt(early_init_dt_scan_memory, NULL);

	/* Change machine number to match the mdesc we're using */
	__machine_arch_type = mdesc_best->nr;

	return mdesc_best;
	}