Add some basic empty infrastructure for DT support on ARM.

v5: - Fix off-by-one error in size calculation of initrd - Stop mucking with cmd_line, and load command line from dt into boot_command_line instead which matches the behaviour of ATAGS booting v3: - moved cmd_line export and initrd setup to this patch to make the series bisectable. - switched to alloc_bootmem_align() for allocation when unflattening the device tree. memblock_alloc() was not the right interface.

Signed-off-by: Jeremy Kerr jeremy.kerr@canonical.com Tested-by: Tony Lindgren tony@atomide.com Signed-off-by: Grant Likely grant.likely@secretlab.ca --- arch/arm/Kconfig | 7 ++++++ arch/arm/include/asm/prom.h | 25 ++++++++++++++++++++++ arch/arm/include/asm/setup.h | 2 ++ arch/arm/kernel/Makefile | 1 + arch/arm/kernel/devtree.c | 47 ++++++++++++++++++++++++++++++++++++++++++ arch/arm/kernel/setup.c | 2 +- arch/arm/mm/init.c | 9 ++++++++ 7 files changed, 92 insertions(+), 1 deletions(-) create mode 100644 arch/arm/include/asm/prom.h create mode 100644 arch/arm/kernel/devtree.c

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 377a7a5..efc7f3c 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1687,6 +1687,13 @@ endmenu

menu "Boot options"

+config USE_OF + bool "Flattened Device Tree support" + select OF + select OF_EARLY_FLATTREE + help + Include support for flattened device tree machine descriptions. + # Compressed boot loader in ROM. Yes, we really want to ask about # TEXT and BSS so we preserve their values in the config files. config ZBOOT_ROM_TEXT diff --git a/arch/arm/include/asm/prom.h b/arch/arm/include/asm/prom.h new file mode 100644 index 0000000..8f1037f --- /dev/null +++ b/arch/arm/include/asm/prom.h @@ -0,0 +1,25 @@ +/* + * arch/arm/include/asm/prom.h + * + * 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. + * + */ +#ifndef __ASMARM_PROM_H +#define __ASMARM_PROM_H + +#ifdef CONFIG_OF + +#include <asm/setup.h> +#include <asm/irq.h> + +static inline void irq_dispose_mapping(unsigned int virq) +{ + return; +} + +#endif /* CONFIG_OF */ +#endif /* ASMARM_PROM_H */ diff --git a/arch/arm/include/asm/setup.h b/arch/arm/include/asm/setup.h index 95176af..93b4702 100644 --- a/arch/arm/include/asm/setup.h +++ b/arch/arm/include/asm/setup.h @@ -217,6 +217,8 @@ extern struct meminfo meminfo; #define bank_phys_end(bank) ((bank)->start + (bank)->size) #define bank_phys_size(bank) (bank)->size

+extern int arm_add_memory(phys_addr_t start, unsigned long size); + #endif /* __KERNEL__ */

#endif diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 8d95446..908c78c 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -44,6 +44,7 @@ obj-$(CONFIG_ARM_THUMBEE) += thumbee.o obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_ARM_UNWIND) += unwind.o obj-$(CONFIG_HAVE_TCM) += tcm.o +obj-$(CONFIG_OF) += devtree.o obj-$(CONFIG_CRASH_DUMP) += crash_dump.o obj-$(CONFIG_SWP_EMULATE) += swp_emulate.o CFLAGS_swp_emulate.o := -Wa,-march=armv7-a diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c new file mode 100644 index 0000000..75e3df8 --- /dev/null +++ b/arch/arm/kernel/devtree.c @@ -0,0 +1,47 @@ +/* + * 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> + +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); +} + +/** + * 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); diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 006c1e8..109997e 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -466,7 +466,7 @@ static struct machine_desc * __init setup_machine(unsigned int nr) /* can't use cpu_relax() here as it may require MMU setup */; }

-static int __init arm_add_memory(phys_addr_t start, unsigned long size) +int __init arm_add_memory(phys_addr_t start, unsigned long size) { struct membank *bank = &meminfo.bank[meminfo.nr_banks];

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index e5f6fc4..26c4054 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -15,6 +15,7 @@ #include <linux/mman.h> #include <linux/nodemask.h> #include <linux/initrd.h> +#include <linux/of_fdt.h> #include <linux/highmem.h> #include <linux/gfp.h> #include <linux/memblock.h> @@ -71,6 +72,14 @@ static int __init parse_tag_initrd2(const struct tag *tag)

__tagtable(ATAG_INITRD2, parse_tag_initrd2);

+#ifdef CONFIG_OF_FLATTREE +void __init early_init_dt_setup_initrd_arch(unsigned long start, unsigned long end) +{ + phys_initrd_start = start; + phys_initrd_size = end - start; +} +#endif /* CONFIG_OF_FLATTREE */ + /* * This keeps memory configuration data used by a couple memory * initialization functions, as well as show_mem() for the skipping

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 Signed-off-by: Grant Likely grant.likely@secretlab.ca --- arch/arm/include/asm/mach/arch.h | 2 + arch/arm/include/asm/prom.h | 12 +++++ arch/arm/include/asm/setup.h | 2 + arch/arm/kernel/devtree.c | 98 ++++++++++++++++++++++++++++++++++++++ arch/arm/kernel/setup.c | 23 +++++++-- arch/arm/mm/init.c | 2 + 6 files changed, 135 insertions(+), 4 deletions(-)

diff --git a/arch/arm/include/asm/mach/arch.h b/arch/arm/include/asm/mach/arch.h index 4764e67..946f4d7 100644 --- a/arch/arm/include/asm/mach/arch.h +++ b/arch/arm/include/asm/mach/arch.h @@ -18,6 +18,8 @@ struct machine_desc { unsigned int nr; /* architecture number */ const char *name; /* architecture name */ unsigned long boot_params; /* tagged list */ + const char **dt_compat; /* array of device tree + * 'compatible' strings */

unsigned int nr_irqs; /* number of IRQs */

diff --git a/arch/arm/include/asm/prom.h b/arch/arm/include/asm/prom.h index 8f1037f..11b8708 100644 --- a/arch/arm/include/asm/prom.h +++ b/arch/arm/include/asm/prom.h @@ -21,5 +21,17 @@ static inline void irq_dispose_mapping(unsigned int virq) return; }

+extern struct machine_desc *setup_machine_fdt(unsigned int dt_phys); +extern void arm_dt_memblock_reserve(void); + +#else /* CONFIG_OF */ + +static inline struct machine_desc *setup_machine_fdt(unsigned int dt_phys) +{ + return NULL; +} + +static inline void arm_dt_memblock_reserve(void) { } + #endif /* CONFIG_OF */ #endif /* ASMARM_PROM_H */ diff --git a/arch/arm/include/asm/setup.h b/arch/arm/include/asm/setup.h index 93b4702..ee2ad8a 100644 --- a/arch/arm/include/asm/setup.h +++ b/arch/arm/include/asm/setup.h @@ -218,6 +218,8 @@ extern struct meminfo meminfo; #define bank_phys_size(bank) (bank)->size

extern int arm_add_memory(phys_addr_t start, unsigned long size); +extern void early_print(const char *str, ...); +extern void dump_machine_table(void);

#endif /* __KERNEL__ */

diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c index 75e3df8..a701e42 100644 --- a/arch/arm/kernel/devtree.c +++ b/arch/arm/kernel/devtree.c @@ -21,6 +21,8 @@

#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) { @@ -32,6 +34,102 @@ 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; + + 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# * diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 42c2f0c..05db25e 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -20,6 +20,7 @@ #include <linux/screen_info.h> #include <linux/init.h> #include <linux/kexec.h> +#include <linux/of_fdt.h> #include <linux/crash_dump.h> #include <linux/root_dev.h> #include <linux/cpu.h> @@ -42,6 +43,7 @@ #include <asm/cachetype.h> #include <asm/tlbflush.h>

+#include <asm/prom.h> #include <asm/mach/arch.h> #include <asm/mach/irq.h> #include <asm/mach/time.h> @@ -309,7 +311,7 @@ static void __init cacheid_init(void) */ extern struct proc_info_list *lookup_processor_type(unsigned int);

-static void __init early_print(const char *str, ...) +void __init early_print(const char *str, ...) { extern void printascii(const char *); char buf[256]; @@ -439,7 +441,7 @@ void cpu_init(void) : "r14"); }

-static void __init dump_machine_table(void) +void __init dump_machine_table(void) { struct machine_desc *p;

@@ -837,8 +839,17 @@ static struct machine_desc * __init setup_machine_tags(unsigned int nr) if (tags->hdr.tag != ATAG_CORE) convert_to_tag_list(tags); #endif - if (tags->hdr.tag != ATAG_CORE) + + if (tags->hdr.tag != ATAG_CORE) { +#if defined(CONFIG_OF) + /* + * If CONFIG_OF is set, then assume this is a reasonably + * modern system that should pass boot parameters + */ + early_print("Warning: Neither atags nor dtb found\n"); +#endif tags = (struct tag *)&init_tags; + }

if (mdesc->fixup) mdesc->fixup(mdesc, tags, &from, &meminfo); @@ -864,7 +875,9 @@ void __init setup_arch(char **cmdline_p) unwind_init();

setup_processor(); - mdesc = setup_machine_tags(machine_arch_type); + mdesc = setup_machine_fdt(__atags_pointer); + if (!mdesc) + mdesc = setup_machine_tags(machine_arch_type); machine_desc = mdesc; machine_name = mdesc->name;

@@ -887,6 +900,8 @@ void __init setup_arch(char **cmdline_p) paging_init(mdesc); request_standard_resources(mdesc);

+ unflatten_device_tree(); + #ifdef CONFIG_SMP if (is_smp()) smp_init_cpus(); diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index 26c4054..b265975 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -22,6 +22,7 @@ #include <linux/sort.h>

#include <asm/mach-types.h> +#include <asm/prom.h> #include <asm/sections.h> #include <asm/setup.h> #include <asm/sizes.h> @@ -322,6 +323,7 @@ void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc) #endif

arm_mm_memblock_reserve(); + arm_dt_memblock_reserve();

/* reserve any platform specific memblock areas */ if (mdesc->reserve)