5 files changed, 226 insertions, 42 deletions

diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 8d95446150a..908c78cb1d1 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 00000000000..a701e4226a6
--- /dev/null
+++ b/arch/arm/kernel/devtree.c
@@ -0,0 +1,145 @@
+/*
+ *  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;
+
+        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);
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index c84b57d27d0..854bd22380d 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S
@@ -15,6 +15,12 @@
 #define ATAG_CORE_SIZE ((2*4 + 3*4) >> 2)
 #define ATAG_CORE_SIZE_EMPTY ((2*4) >> 2)
 
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define OF_DT_MAGIC 0xd00dfeed
+#else
+#define OF_DT_MAGIC 0xedfe0dd0 /* 0xd00dfeed in big-endian */
+#endif
+
 /*
  * Exception handling.  Something went wrong and we can't proceed.  We
  * ought to tell the user, but since we don't have any guarantee that
@@ -28,20 +34,26 @@
 
 /* Determine validity of the r2 atags pointer.  The heuristic requires
  * that the pointer be aligned, in the first 16k of physical RAM and
- * that the ATAG_CORE marker is first and present.  Future revisions
+ * that the ATAG_CORE marker is first and present.  If CONFIG_OF_FLATTREE
+ * is selected, then it will also accept a dtb pointer.  Future revisions
  * of this function may be more lenient with the physical address and
  * may also be able to move the ATAGS block if necessary.
  *
  * Returns:
- *  r2 either valid atags pointer, or zero
+ *  r2 either valid atags pointer, valid dtb pointer, or zero
  *  r5, r6 corrupted
  */
 __vet_atags:
         tst     r2, #0x3                        @ aligned?
         bne     1f
 
-        ldr     r5, [r2, #0]                    @ is first tag ATAG_CORE?
-        cmp     r5, #ATAG_CORE_SIZE
+        ldr     r5, [r2, #0]
+#ifdef CONFIG_OF_FLATTREE
+        ldr     r6, =OF_DT_MAGIC                @ is it a DTB?
+        cmp     r5, r6
+        beq     2f
+#endif
+        cmp     r5, #ATAG_CORE_SIZE             @ is first tag ATAG_CORE?
         cmpne   r5, #ATAG_CORE_SIZE_EMPTY
         bne     1f
         ldr     r5, [r2, #4]
@@ -49,7 +61,7 @@ __vet_atags:
         cmp     r5, r6
         bne     1f
 
-        mov     pc, lr                          @ atag pointer is ok
+2:      mov     pc, lr                          @ atag/dtb pointer is ok
 
 1:      mov     r2, #0
         mov     pc, lr
@@ -61,7 +73,7 @@ ENDPROC(__vet_atags)
  *
  *  r0  = cp#15 control register
  *  r1  = machine ID
- *  r2  = atags pointer
+ *  r2  = atags/dtb pointer
  *  r9  = processor ID
  */
         __INIT
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index c9173cfbbc7..a5e5c5b9b48 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -59,7 +59,7 @@
  *
  * This is normally called from the decompressor code.  The requirements
  * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
- * r1 = machine nr, r2 = atags pointer.
+ * r1 = machine nr, r2 = atags or dtb pointer.
  *
  * This code is mostly position independent, so if you link the kernel at
  * 0xc0008000, you call this at __pa(0xc0008000).
@@ -91,7 +91,7 @@ ENTRY(stext)
 #endif
 
         /*
-         * r1 = machine no, r2 = atags,
+         * r1 = machine no, r2 = atags or dtb,
          * r8 = phys_offset, r9 = cpuid, r10 = procinfo
          */
         bl      __vet_atags
@@ -339,7 +339,7 @@ __secondary_data:
  *
  *  r0  = cp#15 control register
  *  r1  = machine ID
- *  r2  = atags pointer
+ *  r2  = atags or dtb pointer
  *  r4  = page table pointer
  *  r9  = processor ID
  *  r13 = *virtual* address to jump to upon completion
@@ -376,7 +376,7 @@ ENDPROC(__enable_mmu)
  *
  *  r0  = cp#15 control register
  *  r1  = machine ID
- *  r2  = atags pointer
+ *  r2  = atags or dtb pointer
  *  r9  = processor ID
  *  r13 = *virtual* address to jump to upon completion
  *
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 6dce209a623..ed11fb08b05 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];
@@ -439,25 +441,12 @@ void cpu_init(void)
             : "r14");
 }
 
-static struct machine_desc * __init setup_machine(unsigned int nr)
+void __init dump_machine_table(void)
 {
-        extern struct machine_desc __arch_info_begin[], __arch_info_end[];
         struct machine_desc *p;
 
-        /*
-         * locate machine in the list of supported machines.
-         */
-        for (p = __arch_info_begin; p < __arch_info_end; p++)
-                if (nr == p->nr) {
-                        printk("Machine: %s\n", p->name);
-                        return p;
-                }
-
-        early_print("\n"
-                "Error: unrecognized/unsupported machine ID (r1 = 0x%08x).\n\n"
-                "Available machine support:\n\nID (hex)\tNAME\n", nr);
-
-        for (p = __arch_info_begin; p < __arch_info_end; p++)
+        early_print("Available machine support:\n\nID (hex)\tNAME\n");
+        for_each_machine_desc(p)
                 early_print("%08x\t%s\n", p->nr, p->name);
 
         early_print("\nPlease check your kernel config and/or bootloader.\n");
@@ -466,7 +455,7 @@ 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];
 
@@ -801,23 +790,29 @@ static void __init squash_mem_tags(struct tag *tag)
                         tag->hdr.tag = ATAG_NONE;
 }
 
-void __init setup_arch(char **cmdline_p)
+static struct machine_desc * __init setup_machine_tags(unsigned int nr)
 {
         struct tag *tags = (struct tag *)&init_tags;
-        struct machine_desc *mdesc;
+        struct machine_desc *mdesc = NULL, *p;
         char *from = default_command_line;
 
         init_tags.mem.start = PHYS_OFFSET;
 
-        unwind_init();
-
-        setup_processor();
-        mdesc = setup_machine(machine_arch_type);
-        machine_desc = mdesc;
-        machine_name = mdesc->name;
+        /*
+         * locate machine in the list of supported machines.
+         */
+        for_each_machine_desc(p)
+                if (nr == p->nr) {
+                        printk("Machine: %s\n", p->name);
+                        mdesc = p;
+                        break;
+                }
 
-        if (mdesc->soft_reboot)
-                reboot_setup("s");
+        if (!mdesc) {
+                early_print("\nError: unrecognized/unsupported machine ID"
+                        " (r1 = 0x%08x).\n\n", nr);
+                dump_machine_table(); /* does not return */
+        }
 
         if (__atags_pointer)
                 tags = phys_to_virt(__atags_pointer);
@@ -849,8 +844,17 @@ void __init setup_arch(char **cmdline_p)
         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);
@@ -862,14 +866,34 @@ void __init setup_arch(char **cmdline_p)
                 parse_tags(tags);
         }
 
+        /* parse_early_param needs a boot_command_line */
+        strlcpy(boot_command_line, from, COMMAND_LINE_SIZE);
+
+        return mdesc;
+}
+
+
+void __init setup_arch(char **cmdline_p)
+{
+        struct machine_desc *mdesc;
+
+        unwind_init();
+
+        setup_processor();
+        mdesc = setup_machine_fdt(__atags_pointer);
+        if (!mdesc)
+                mdesc = setup_machine_tags(machine_arch_type);
+        machine_desc = mdesc;
+        machine_name = mdesc->name;
+
+        if (mdesc->soft_reboot)
+                reboot_setup("s");
+
         init_mm.start_code = (unsigned long) _text;
         init_mm.end_code   = (unsigned long) _etext;
         init_mm.end_data   = (unsigned long) _edata;
         init_mm.brk        = (unsigned long) _end;
 
-        /* parse_early_param needs a boot_command_line */
-        strlcpy(boot_command_line, from, COMMAND_LINE_SIZE);
-
         /* populate cmd_line too for later use, preserving boot_command_line */
         strlcpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
         *cmdline_p = cmd_line;
@@ -881,6 +905,8 @@ 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();