8 files changed, 169 insertions, 12 deletions

diff --git a/arch/arc/include/asm/mach_desc.h b/arch/arc/include/asm/mach_desc.h
new file mode 100644
index 000000000000..eaebaf835f85
--- /dev/null
+++ b/arch/arc/include/asm/mach_desc.h
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * based on METAG mach/arch.h (which in turn was based on ARM)
+ *
+ * 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 _ASM_ARC_MACH_DESC_H_
+#define _ASM_ARC_MACH_DESC_H_
+
+/**
+ * struct machine_desc - Board specific callbacks, called from ARC common code
+ *      Provided by each ARC board using MACHINE_START()/MACHINE_END(), so
+ *      a multi-platform kernel builds with array of such descriptors.
+ *      We extend the early DT scan to also match the DT's "compatible" string
+ *      against the @dt_compat of all such descriptors, and one with highest
+ *      "DT score" is selected as global @machine_desc.
+ *
+ * @name:               Board/SoC name
+ * @dt_compat:          Array of device tree 'compatible' strings
+ *                      (XXX: although only 1st entry is looked at)
+ * @init_early:         Very early callback [called from setup_arch()]
+ * @init_irq:           setup external IRQ controllers [called from init_IRQ()]
+ * @init_smp:           for each CPU (e.g. setup IPI)
+ *                      [(M):init_IRQ(), (o):start_kernel_secondary()]
+ * @init_time:          platform specific clocksource/clockevent registration
+ *                      [called from time_init()]
+ * @init_machine:       arch initcall level callback (e.g. populate static
+ *                      platform devices or parse Devicetree)
+ * @init_late:          Late initcall level callback
+ *
+ */
+struct machine_desc {
+        const char              *name;
+        const char              **dt_compat;
+
+        void                    (*init_early)(void);
+        void                    (*init_irq)(void);
+#ifdef CONFIG_SMP
+        void                    (*init_smp)(unsigned int);
+#endif
+        void                    (*init_time)(void);
+        void                    (*init_machine)(void);
+        void                    (*init_late)(void);
+
+};
+
+/*
+ * Current machine - only accessible during boot.
+ */
+extern struct machine_desc *machine_desc;
+
+/*
+ * Machine type table - also only accessible during boot
+ */
+extern struct machine_desc __arch_info_begin[], __arch_info_end[];
+#define for_each_machine_desc(p)                        \
+        for (p = __arch_info_begin; p < __arch_info_end; p++)
+
+static inline struct machine_desc *default_machine_desc(void)
+{
+        /* the default machine is the last one linked in */
+        if (__arch_info_end - 1 < __arch_info_begin)
+                return NULL;
+        return __arch_info_end - 1;
+}
+
+/*
+ * Set of macros to define architecture features.
+ * This is built into a table by the linker.
+ */
+#define MACHINE_START(_type, _name)                     \
+static const struct machine_desc __mach_desc_##_type    \
+__used                                                  \
+__attribute__((__section__(".arch.info.init"))) = {     \
+        .name           = _name,
+
+#define MACHINE_END                             \
+};
+
+extern struct machine_desc *setup_machine_fdt(void *dt);
+#endif
diff --git a/arch/arc/include/asm/prom.h b/arch/arc/include/asm/prom.h
index f54489bc4eca..692d0d0789a7 100644
--- a/arch/arc/include/asm/prom.h
+++ b/arch/arc/include/asm/prom.h
@@ -10,6 +10,5 @@
 #define _ASM_ARC_PROM_H_
 
 #define HAVE_ARCH_DEVTREE_FIXUPS
-extern int __init setup_machine_fdt(void *dt);
 
 #endif
diff --git a/arch/arc/kernel/devtree.c b/arch/arc/kernel/devtree.c
index c8166dc02c38..a7d98b30358b 100644
--- a/arch/arc/kernel/devtree.c
+++ b/arch/arc/kernel/devtree.c
@@ -16,6 +16,7 @@
 #include <linux/of_fdt.h>
 #include <asm/prom.h>
 #include <asm/clk.h>
+#include <asm/mach_desc.h>
 
 /* called from unflatten_device_tree() to bootstrap devicetree itself */
 void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
@@ -30,27 +31,57 @@ void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
  * If a dtb was passed to the kernel, then use it to choose the correct
  * machine_desc and to setup the system.
  */
-int __init setup_machine_fdt(void *dt)
+struct machine_desc * __init setup_machine_fdt(void *dt)
 {
         struct boot_param_header *devtree = dt;
+        struct machine_desc *mdesc = NULL, *mdesc_best = NULL;
+        unsigned int score, mdesc_score = ~1;
         unsigned long dt_root;
-        char *model, *compat;
+        const char *model, *compat;
         void *clk;
         char manufacturer[16];
         unsigned long len;
 
         /* check device tree validity */
         if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
-                return 1;
+                return NULL;
 
-        /* Search the mdescs for the 'best' compatible value match */
         initial_boot_params = devtree;
         dt_root = of_get_flat_dt_root();
 
+        /*
+         * The kernel could be multi-platform enabled, thus could have many
+         * "baked-in" machine descriptors. Search thru all for the best
+         * "compatible" string match.
+         */
+        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;
+
+                pr_err("\n unrecognized device tree list:\n[ ");
+
+                prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
+                if (prop) {
+                        while (size > 0) {
+                                printk("'%s' ", prop);
+                                size -= strlen(prop) + 1;
+                                prop += strlen(prop) + 1;
+                        }
+                }
+                printk("]\n\n");
+
+                machine_halt();
+        }
+
         /* compat = "<manufacturer>,<model>" */
-        compat = of_get_flat_dt_prop(dt_root, "compatible", NULL);
-        if (!compat)
-                compat = "<unknown>";
+        compat =  mdesc_best->dt_compat[0];
 
         model = strchr(compat, ',');
         if (model)
@@ -73,5 +104,5 @@ int __init setup_machine_fdt(void *dt)
         if (clk)
                 arc_set_core_freq(of_read_ulong(clk, len/4));
 
-        return 0;
+        return mdesc_best;
 }
diff --git a/arch/arc/kernel/irq.c b/arch/arc/kernel/irq.c
index df7da2b5a5bd..1198168850e8 100644
--- a/arch/arc/kernel/irq.c
+++ b/arch/arc/kernel/irq.c
@@ -13,6 +13,7 @@
 #include <linux/irqdomain.h>
 #include <asm/sections.h>
 #include <asm/irq.h>
+#include <asm/mach_desc.h>
 
 /*
  * Early Hardware specific Interrupt setup
@@ -125,9 +126,15 @@ void __init init_IRQ(void)
         init_onchip_IRQ();
         plat_init_IRQ();
 
+        /* Any external intc can be setup here */
+        if (machine_desc->init_irq)
+                machine_desc->init_irq();
+
 #ifdef CONFIG_SMP
         /* Master CPU can initialize it's side of IPI */
         arc_platform_smp_init_cpu();
+        if (machine_desc->init_smp)
+                machine_desc->init_smp(smp_processor_id());
 #endif
 }
 
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index 6cc361c6751a..20273b89e545 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -25,12 +25,14 @@
 #include <asm/prom.h>
 #include <asm/unwind.h>
 #include <asm/clk.h>
+#include <asm/mach_desc.h>
 
 #define FIX_PTR(x)  __asm__ __volatile__(";" : "+r"(x))
 
 int running_on_hw = 1;  /* vs. on ISS */
 
 char __initdata command_line[COMMAND_LINE_SIZE];
+struct machine_desc *machine_desc __initdata;
 
 struct task_struct *_current_task[NR_CPUS];     /* For stack switching */
 
@@ -323,8 +325,6 @@ void __init __attribute__((weak)) arc_platform_early_init(void)
 
 void __init setup_arch(char **cmdline_p)
 {
-        int rc;
-
 #ifdef CONFIG_CMDLINE_UBOOT
         /* Make sure that a whitespace is inserted before */
         strlcat(command_line, " ", sizeof(command_line));
@@ -339,13 +339,17 @@ void __init setup_arch(char **cmdline_p)
         strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
         *cmdline_p = command_line;
 
-        rc = setup_machine_fdt(__dtb_start);
+        machine_desc = setup_machine_fdt(__dtb_start);
+        if (!machine_desc)
+                panic("Embedded DT invalid\n");
 
         /* To force early parsing of things like mem=xxx */
         parse_early_param();
 
         /* Platform/board specific: e.g. early console registration */
         arc_platform_early_init();
+        if (machine_desc->init_early)
+                machine_desc->init_early();
 
         setup_processor();
 
@@ -372,6 +376,24 @@ void __init setup_arch(char **cmdline_p)
         arc_unwind_setup();
 }
 
+static int __init customize_machine(void)
+{
+        /* Add platform devices */
+        if (machine_desc->init_machine)
+                machine_desc->init_machine();
+
+        return 0;
+}
+arch_initcall(customize_machine);
+
+static int __init init_late_machine(void)
+{
+        if (machine_desc->init_late)
+                machine_desc->init_late();
+
+        return 0;
+}
+late_initcall(init_late_machine);
 /*
  *  Get CPU information for use by the procfs.
  */
diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
index 1f762ad6969b..ea15f073452f 100644
--- a/arch/arc/kernel/smp.c
+++ b/arch/arc/kernel/smp.c
@@ -32,6 +32,7 @@
 #include <linux/reboot.h>
 #include <asm/processor.h>
 #include <asm/setup.h>
+#include <asm/mach_desc.h>
 
 arch_spinlock_t smp_atomic_ops_lock = __ARCH_SPIN_LOCK_UNLOCKED;
 arch_spinlock_t smp_bitops_lock = __ARCH_SPIN_LOCK_UNLOCKED;
@@ -127,6 +128,8 @@ void __cpuinit start_kernel_secondary(void)
         pr_info("## CPU%u LIVE ##: Executing Code...\n", cpu);
 
         arc_platform_smp_init_cpu();
+        if (machine_desc->init_smp)
+                machine_desc->init_smp(smp_processor_id());
 
         arc_local_timer_setup(cpu);
 
diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c
index 05dba11fdb2d..0ce0e6f76eb0 100644
--- a/arch/arc/kernel/time.c
+++ b/arch/arc/kernel/time.c
@@ -43,6 +43,7 @@
 #include <asm/irq.h>
 #include <asm/arcregs.h>
 #include <asm/clk.h>
+#include <asm/mach_desc.h>
 
 #define ARC_TIMER_MAX   0xFFFFFFFF
 
@@ -258,6 +259,9 @@ void __init time_init(void)
 
         /* sets up the periodic event timer */
         arc_local_timer_setup(smp_processor_id());
+
+        if (machine_desc->init_time)
+                machine_desc->init_time();
 }
 
 #ifdef CONFIG_ARC_HAS_RTSC
diff --git a/arch/arc/kernel/vmlinux.lds.S b/arch/arc/kernel/vmlinux.lds.S
index 8d3b0d447498..622d8b665a68 100644
--- a/arch/arc/kernel/vmlinux.lds.S
+++ b/arch/arc/kernel/vmlinux.lds.S
@@ -75,6 +75,12 @@ SECTIONS
                 SECURITY_INITCALL
         }
 
+        .init.arch.info : {
+                __arch_info_begin = .;
+                *(.arch.info.init)
+                __arch_info_end = .;
+        }
+
         PERCPU_SECTION(L1_CACHE_BYTES)
 
         /*