https://github.com/torvalds/linux
Tip revision: 60d509fa6a9c4653a86ad830e4c4b30360b23f0e authored by Linus Torvalds on 21 April 2013, 21:38:45 UTC
Linux 3.9-rc8
Linux 3.9-rc8
Tip revision: 60d509f
devtree.c
/*
* 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] = 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++;
}
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 (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
*
* 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;
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;
}