linux/arch/arm/kernel/devtree.c

146 lines
3.9 KiB
C
Raw Normal View History

/*
* 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>
arm/dt: probe for platforms via the device tree If a dtb is passed to the kernel then the kernel needs to iterate through compiled-in mdescs looking for one that matches and move the dtb data to a safe location before it gets accidentally overwritten by the kernel. This patch creates a new function, setup_machine_fdt() which is analogous to the setup_machine_atags() created in the previous patch. It does all the early setup needed to use a device tree machine description. v5: - Print warning with neither dtb nor atags are passed to the kernel - Fix bug in setting of __machine_arch_type to the selected machine, not just the last machine in the list. Reported-by: Tixy <tixy@yxit.co.uk> - Copy command line directly into boot_command_line instead of cmd_line v4: - Dump some output when a matching machine_desc cannot be found v3: - Added processing of reserved list. - Backed out the v2 change that copied instead of reserved the dtb. dtb is reserved again and the real problem was fixed by using alloc_bootmem_align() for early allocation of RAM for unflattening the tree. - Moved cmd_line and initrd changes to earlier patch to make series bisectable. v2: Changed to save the dtb by copying into an allocated buffer. - Since the dtb will very likely be passed in the first 16k of ram where the interrupt vectors live, memblock_reserve() is insufficient to protect the dtb data. [based on work originally written by Jeremy Kerr <jeremy.kerr@canonical.com>] Tested-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-04-28 22:27:21 +02:00
#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);
}
arm/dt: probe for platforms via the device tree If a dtb is passed to the kernel then the kernel needs to iterate through compiled-in mdescs looking for one that matches and move the dtb data to a safe location before it gets accidentally overwritten by the kernel. This patch creates a new function, setup_machine_fdt() which is analogous to the setup_machine_atags() created in the previous patch. It does all the early setup needed to use a device tree machine description. v5: - Print warning with neither dtb nor atags are passed to the kernel - Fix bug in setting of __machine_arch_type to the selected machine, not just the last machine in the list. Reported-by: Tixy <tixy@yxit.co.uk> - Copy command line directly into boot_command_line instead of cmd_line v4: - Dump some output when a matching machine_desc cannot be found v3: - Added processing of reserved list. - Backed out the v2 change that copied instead of reserved the dtb. dtb is reserved again and the real problem was fixed by using alloc_bootmem_align() for early allocation of RAM for unflattening the tree. - Moved cmd_line and initrd changes to earlier patch to make series bisectable. v2: Changed to save the dtb by copying into an allocated buffer. - Since the dtb will very likely be passed in the first 16k of ram where the interrupt vectors live, memblock_reserve() is insufficient to protect the dtb data. [based on work originally written by Jeremy Kerr <jeremy.kerr@canonical.com>] Tested-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-04-28 22:27:21 +02:00
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;
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);