linux/arch/arm/kernel/devtree.c
Nicolas Pitre f506cd48a4 ARM: 6953/1: DT: don't try to access physical address zero
If the DT physical address is zero, this is equivalent to no DT.
Especially when the actual RAM physical address is not located at zero,
the result of phys_to_virt() would point to la-la-land and crash the
kernel, which crash is completely silent this early during boot.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-09 10:15:06 +01:00

149 lines
3.9 KiB
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/module.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/setup.h>
#include <asm/page.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);
}
}
/**
* 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;
}
/**
* irq_create_of_mapping - Hook to resolve OF irq specifier into a Linux irq#
*
* Currently the mapping mechanism is trivial; simple flat hwirq numbers are
* mapped 1:1 onto Linux irq numbers. Cascaded irq controllers are not
* supported.
*/
unsigned int irq_create_of_mapping(struct device_node *controller,
const u32 *intspec, unsigned int intsize)
{
return intspec[0];
}
EXPORT_SYMBOL_GPL(irq_create_of_mapping);