f506cd48a4
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>
149 lines
3.9 KiB
C
149 lines
3.9 KiB
C
/*
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* linux/arch/arm/kernel/devtree.c
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*
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* Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/bootmem.h>
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#include <linux/memblock.h>
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#include <linux/of.h>
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#include <linux/of_fdt.h>
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#include <linux/of_irq.h>
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#include <linux/of_platform.h>
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#include <asm/setup.h>
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#include <asm/page.h>
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#include <asm/mach/arch.h>
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#include <asm/mach-types.h>
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void __init early_init_dt_add_memory_arch(u64 base, u64 size)
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{
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arm_add_memory(base, size);
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}
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void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
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{
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return alloc_bootmem_align(size, align);
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}
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void __init arm_dt_memblock_reserve(void)
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{
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u64 *reserve_map, base, size;
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if (!initial_boot_params)
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return;
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/* Reserve the dtb region */
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memblock_reserve(virt_to_phys(initial_boot_params),
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be32_to_cpu(initial_boot_params->totalsize));
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/*
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* Process the reserve map. This will probably overlap the initrd
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* and dtb locations which are already reserved, but overlaping
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* doesn't hurt anything
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*/
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reserve_map = ((void*)initial_boot_params) +
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be32_to_cpu(initial_boot_params->off_mem_rsvmap);
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while (1) {
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base = be64_to_cpup(reserve_map++);
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size = be64_to_cpup(reserve_map++);
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if (!size)
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break;
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memblock_reserve(base, size);
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}
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}
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/**
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* setup_machine_fdt - Machine setup when an dtb was passed to the kernel
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* @dt_phys: physical address of dt blob
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*
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* If a dtb was passed to the kernel in r2, then use it to choose the
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* correct machine_desc and to setup the system.
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*/
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struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
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{
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struct boot_param_header *devtree;
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struct machine_desc *mdesc, *mdesc_best = NULL;
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unsigned int score, mdesc_score = ~1;
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unsigned long dt_root;
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const char *model;
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if (!dt_phys)
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return NULL;
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devtree = phys_to_virt(dt_phys);
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/* check device tree validity */
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if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
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return NULL;
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/* Search the mdescs for the 'best' compatible value match */
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initial_boot_params = devtree;
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dt_root = of_get_flat_dt_root();
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for_each_machine_desc(mdesc) {
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score = of_flat_dt_match(dt_root, mdesc->dt_compat);
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if (score > 0 && score < mdesc_score) {
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mdesc_best = mdesc;
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mdesc_score = score;
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}
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}
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if (!mdesc_best) {
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const char *prop;
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long size;
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early_print("\nError: unrecognized/unsupported "
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"device tree compatible list:\n[ ");
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prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
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while (size > 0) {
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early_print("'%s' ", prop);
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size -= strlen(prop) + 1;
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prop += strlen(prop) + 1;
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}
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early_print("]\n\n");
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dump_machine_table(); /* does not return */
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}
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model = of_get_flat_dt_prop(dt_root, "model", NULL);
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if (!model)
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model = of_get_flat_dt_prop(dt_root, "compatible", NULL);
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if (!model)
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model = "<unknown>";
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pr_info("Machine: %s, model: %s\n", mdesc_best->name, model);
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/* Retrieve various information from the /chosen node */
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of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
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/* Initialize {size,address}-cells info */
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of_scan_flat_dt(early_init_dt_scan_root, NULL);
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/* Setup memory, calling early_init_dt_add_memory_arch */
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of_scan_flat_dt(early_init_dt_scan_memory, NULL);
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/* Change machine number to match the mdesc we're using */
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__machine_arch_type = mdesc_best->nr;
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return mdesc_best;
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}
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/**
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* irq_create_of_mapping - Hook to resolve OF irq specifier into a Linux irq#
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*
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* Currently the mapping mechanism is trivial; simple flat hwirq numbers are
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* mapped 1:1 onto Linux irq numbers. Cascaded irq controllers are not
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* supported.
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*/
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unsigned int irq_create_of_mapping(struct device_node *controller,
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const u32 *intspec, unsigned int intsize)
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{
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return intspec[0];
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}
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EXPORT_SYMBOL_GPL(irq_create_of_mapping);
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