ARC: Boot #1: low-level, setup_arch(), /proc/cpuinfo, mem init

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

8 files changed, 506 insertions, 0 deletions

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 756beffd20cb..a3538493e353 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -23,7 +23,9 @@ config ARC
         select GENERIC_SIGALTSTACK
         select GENERIC_SMP_IDLE_THREAD
         select HAVE_GENERIC_HARDIRQS
+        select HAVE_MEMBLOCK
         select MODULES_USE_ELF_RELA
+        select NO_BOOTMEM
 
 config SCHED_OMIT_FRAME_POINTER
         def_bool y
diff --git a/arch/arc/include/asm/arcregs.h b/arch/arc/include/asm/arcregs.h
index 1c24485fd04b..9e42611e39d3 100644
--- a/arch/arc/include/asm/arcregs.h
+++ b/arch/arc/include/asm/arcregs.h
@@ -258,6 +258,11 @@
         }                                               \
 }
 
+/* Helpers */
+#define TO_KB(bytes)            ((bytes) >> 10)
+#define TO_MB(bytes)            (TO_KB(bytes) >> 10)
+#define PAGES_TO_KB(n_pages)    ((n_pages) << (PAGE_SHIFT - 10))
+#define PAGES_TO_MB(n_pages)    (PAGES_TO_KB(n_pages) >> 10)
 
 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
 /* These DPFP regs need to be saved/restored across ctx-sw */
diff --git a/arch/arc/include/asm/setup.h b/arch/arc/include/asm/setup.h
new file mode 100644
index 000000000000..ab427e6a2cb5
--- /dev/null
+++ b/arch/arc/include/asm/setup.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.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 __ASMARC_SETUP_H
+#define __ASMARC_SETUP_H
+
+#include <linux/types.h>
+
+#define COMMAND_LINE_SIZE 256
+
+extern int root_mountflags, end_mem;
+extern int running_on_hw;
+
+void __init setup_processor(void);
+void __init setup_arch_memory(void);
+
+#endif /* __ASMARC_SETUP_H */
diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
new file mode 100644
index 000000000000..e63f6a43abb1
--- /dev/null
+++ b/arch/arc/kernel/head.S
@@ -0,0 +1,78 @@
+/*
+ * ARC CPU startup Code
+ *
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.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.
+ *
+ * Vineetg: Dec 2007
+ *  -Check if we are running on Simulator or on real hardware
+ *      to skip certain things during boot on simulator
+ */
+
+#include <asm/asm-offsets.h>
+#include <asm/entry.h>
+#include <linux/linkage.h>
+#include <asm/arcregs.h>
+
+        .cpu A7
+
+        .section .init.text, "ax",@progbits
+        .type stext, @function
+        .globl stext
+stext:
+        ;-------------------------------------------------------------------
+        ; Don't clobber r0-r4 yet. It might have bootloader provided info
+        ;-------------------------------------------------------------------
+
+        ; Clear BSS before updating any globals
+        ; XXX: use ZOL here
+        mov     r5, __bss_start
+        mov     r6, __bss_stop
+1:
+        st.ab   0, [r5,4]
+        brlt    r5, r6, 1b
+
+#ifdef CONFIG_CMDLINE_UBOOT
+        ; support for bootloader provided cmdline
+        ;    If cmdline passed by u-boot, then
+        ;    r0 = 1  (because ATAGS parsing, now retired, used to use 0)
+        ;    r1 = magic number (board identity)
+        ;    r2 = addr of cmdline string (somewhere in memory/flash)
+
+        brne    r0, 1, .Lother_bootup_chores    ; u-boot didn't pass cmdline
+        breq    r2, 0, .Lother_bootup_chores    ; or cmdline is NULL
+
+        mov     r5, @command_line
+1:
+        ldb.ab  r6, [r2, 1]
+        breq    r6, 0, .Lother_bootup_chores
+        b.d     1b
+        stb.ab  r6, [r5, 1]
+#endif
+
+.Lother_bootup_chores:
+
+        ; Identify if running on ISS vs Silicon
+        ;       IDENTITY Reg [ 3  2  1  0 ]
+        ;       (chip-id)      ^^^^^            ==> 0xffff for ISS
+        lr      r0, [identity]
+        lsr     r3, r0, 16
+        cmp     r3, 0xffff
+        mov.z   r4, 0
+        mov.nz  r4, 1
+        st      r4, [@running_on_hw]
+
+        ; setup "current" tsk and optionally cache it in dedicated r25
+        mov     r9, @init_task
+        SET_CURR_TASK_ON_CPU  r9, r0    ; r9 = tsk, r0 = scratch
+
+        ; setup stack (fp, sp)
+        mov     fp, 0
+
+        ; tsk->thread_info is really a PAGE, whose bottom hoists stack
+        GET_TSK_STACK_BASE r9, sp       ; r9 = tsk, sp = stack base(output)
+
+        j       start_kernel    ; "C" entry point
diff --git a/arch/arc/kernel/reset.c b/arch/arc/kernel/reset.c
new file mode 100644
index 000000000000..e227a2b1c943
--- /dev/null
+++ b/arch/arc/kernel/reset.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2011-2012 Synopsys, Inc. (www.synopsys.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/kernel.h>
+#include <linux/printk.h>
+#include <linux/reboot.h>
+#include <linux/pm.h>
+
+void machine_halt(void)
+{
+        /* Halt the processor */
+        __asm__ __volatile__("flag  1\n");
+}
+
+void machine_restart(char *__unused)
+{
+        /* Soft reset : jump to reset vector */
+        pr_info("Put your restart handler here\n");
+        machine_halt();
+}
+
+void machine_power_off(void)
+{
+        /* FIXME ::  power off ??? */
+        machine_halt();
+}
+
+void (*pm_power_off) (void) = NULL;
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
new file mode 100644
index 000000000000..82ac20603398
--- /dev/null
+++ b/arch/arc/kernel/setup.c
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.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/seq_file.h>
+#include <linux/fs.h>
+#include <linux/delay.h>
+#include <linux/root_dev.h>
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/cpu.h>
+#include <asm/arcregs.h>
+#include <asm/tlb.h>
+#include <asm/cache.h>
+#include <asm/setup.h>
+#include <asm/page.h>
+#include <asm/irq.h>
+#include <asm/arcregs.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 task_struct *_current_task[NR_CPUS];     /* For stack switching */
+
+struct cpuinfo_arc cpuinfo_arc700[NR_CPUS];
+
+void __init read_arc_build_cfg_regs(void)
+{
+        read_decode_mmu_bcr();
+        read_decode_cache_bcr();
+}
+
+/*
+ * Initialize and setup the processor core
+ * This is called by all the CPUs thus should not do special case stuff
+ *    such as only for boot CPU etc
+ */
+
+void __init setup_processor(void)
+{
+        read_arc_build_cfg_regs();
+        arc_init_IRQ();
+        arc_mmu_init();
+        arc_cache_init();
+}
+
+void __init __attribute__((weak)) arc_platform_early_init(void)
+{
+}
+
+void __init setup_arch(char **cmdline_p)
+{
+#ifdef CONFIG_CMDLINE_UBOOT
+        /* Make sure that a whitespace is inserted before */
+        strlcat(command_line, " ", sizeof(command_line));
+#endif
+        /*
+         * Append .config cmdline to base command line, which might already
+         * contain u-boot "bootargs" (handled by head.S, if so configured)
+         */
+        strlcat(command_line, CONFIG_CMDLINE, sizeof(command_line));
+
+        /* Save unparsed command line copy for /proc/cmdline */
+        strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
+        *cmdline_p = command_line;
+
+        /* To force early parsing of things like mem=xxx */
+        parse_early_param();
+
+        /* Platform/board specific: e.g. early console registration */
+        arc_platform_early_init();
+
+        setup_processor();
+
+        setup_arch_memory();
+
+        /* Can be issue if someone passes cmd line arg "ro"
+         * But that is unlikely so keeping it as it is
+         */
+        root_mountflags &= ~MS_RDONLY;
+
+        console_verbose();
+
+#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
+        conswitchp = &dummy_con;
+#endif
+
+}
+
+/*
+ *  Get CPU information for use by the procfs.
+ */
+
+#define cpu_to_ptr(c)   ((void *)(0xFFFF0000 | (unsigned int)(c)))
+#define ptr_to_cpu(p)   (~0xFFFF0000UL & (unsigned int)(p))
+
+static int show_cpuinfo(struct seq_file *m, void *v)
+{
+        char *str;
+        int cpu_id = ptr_to_cpu(v);
+
+        str = (char *)__get_free_page(GFP_TEMPORARY);
+        if (!str)
+                goto done;
+
+        seq_printf(m, "ARC700 #%d\n", cpu_id);
+
+        seq_printf(m, "Bogo MIPS : \t%lu.%02lu\n",
+                   loops_per_jiffy / (500000 / HZ),
+                   (loops_per_jiffy / (5000 / HZ)) % 100);
+
+        free_page((unsigned long)str);
+done:
+        seq_printf(m, "\n\n");
+
+        return 0;
+}
+
+static void *c_start(struct seq_file *m, loff_t *pos)
+{
+        /*
+         * Callback returns cpu-id to iterator for show routine, NULL to stop.
+         * However since NULL is also a valid cpu-id (0), we use a round-about
+         * way to pass it w/o having to kmalloc/free a 2 byte string.
+         * Encode cpu-id as 0xFFcccc, which is decoded by show routine.
+         */
+        return *pos < num_possible_cpus() ? cpu_to_ptr(*pos) : NULL;
+}
+
+static void *c_next(struct seq_file *m, void *v, loff_t *pos)
+{
+        ++*pos;
+        return c_start(m, pos);
+}
+
+static void c_stop(struct seq_file *m, void *v)
+{
+}
+
+const struct seq_operations cpuinfo_op = {
+        .start  = c_start,
+        .next   = c_next,
+        .stop   = c_stop,
+        .show   = show_cpuinfo
+};
+
+static DEFINE_PER_CPU(struct cpu, cpu_topology);
+
+static int __init topology_init(void)
+{
+        int cpu;
+
+        for_each_present_cpu(cpu)
+            register_cpu(&per_cpu(cpu_topology, cpu), cpu);
+
+        return 0;
+}
+
+subsys_initcall(topology_init);
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
new file mode 100644
index 000000000000..63da3478521f
--- /dev/null
+++ b/arch/arc/mm/init.c
@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.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/kernel.h>
+#include <linux/mm.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#ifdef CONFIG_BLOCK_DEV_RAM
+#include <linux/blk.h>
+#endif
+#include <linux/swap.h>
+#include <linux/module.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/sections.h>
+#include <asm/arcregs.h>
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
+char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
+EXPORT_SYMBOL(empty_zero_page);
+
+/* Default tot mem from .config */
+static unsigned long arc_mem_sz = CONFIG_ARC_PLAT_SDRAM_SIZE;
+
+/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
+static int __init setup_mem_sz(char *str)
+{
+        arc_mem_sz = memparse(str, NULL) & PAGE_MASK;
+
+        /* early console might not be setup yet - it will show up later */
+        pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(arc_mem_sz));
+
+        return 0;
+}
+early_param("mem", setup_mem_sz);
+
+/*
+ * First memory setup routine called from setup_arch()
+ * 1. setup swapper's mm @init_mm
+ * 2. Count the pages we have and setup bootmem allocator
+ * 3. zone setup
+ */
+void __init setup_arch_memory(void)
+{
+        unsigned long zones_size[MAX_NR_ZONES] = { 0, 0 };
+        unsigned long end_mem = CONFIG_LINUX_LINK_BASE + arc_mem_sz;
+
+        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;
+
+        /*
+         * We do it here, so that memory is correctly instantiated
+         * even if "mem=xxx" cmline over-ride is not given
+         */
+        memblock_add(CONFIG_LINUX_LINK_BASE, arc_mem_sz);
+
+        /*------------- externs in mm need setting up ---------------*/
+
+        /* first page of system - kernel .vector starts here */
+        min_low_pfn = PFN_DOWN(CONFIG_LINUX_LINK_BASE);
+
+        /* Last usable page of low mem (no HIGHMEM yet for ARC port) */
+        max_low_pfn = max_pfn = PFN_DOWN(end_mem);
+
+        max_mapnr = num_physpages = max_low_pfn - min_low_pfn;
+
+        /*------------- reserve kernel image -----------------------*/
+        memblock_reserve(CONFIG_LINUX_LINK_BASE,
+                         __pa(_end) - CONFIG_LINUX_LINK_BASE);
+
+        memblock_dump_all();
+
+        /*-------------- node setup --------------------------------*/
+        memset(zones_size, 0, sizeof(zones_size));
+        zones_size[ZONE_NORMAL] = num_physpages;
+
+        /*
+         * We can't use the helper free_area_init(zones[]) because it uses
+         * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
+         * when our kernel doesn't start at PAGE_OFFSET, i.e.
+         * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
+         */
+        free_area_init_node(0,                  /* node-id */
+                            zones_size,         /* num pages per zone */
+                            min_low_pfn,        /* first pfn of node */
+                            NULL);              /* NO holes */
+}
+
+/*
+ * mem_init - initializes memory
+ *
+ * Frees up bootmem
+ * Calculates and displays memory available/used
+ */
+void __init mem_init(void)
+{
+        int codesize, datasize, initsize, reserved_pages, free_pages;
+        int tmp;
+
+        high_memory = (void *)(CONFIG_LINUX_LINK_BASE + arc_mem_sz);
+
+        totalram_pages = free_all_bootmem();
+
+        /* count all reserved pages [kernel code/data/mem_map..] */
+        reserved_pages = 0;
+        for (tmp = 0; tmp < max_mapnr; tmp++)
+                if (PageReserved(mem_map + tmp))
+                        reserved_pages++;
+
+        /* XXX: nr_free_pages() is equivalent */
+        free_pages = max_mapnr - reserved_pages;
+
+        /*
+         * For the purpose of display below, split the "reserve mem"
+         * kernel code/data is already shown explicitly,
+         * Show any other reservations (mem_map[ ] et al)
+         */
+        reserved_pages -= (((unsigned int)_end - CONFIG_LINUX_LINK_BASE) >>
+                                                                PAGE_SHIFT);
+
+        codesize = _etext - _text;
+        datasize = _end - _etext;
+        initsize = __init_end - __init_begin;
+
+        pr_info("Memory Available: %dM / %ldM (%dK code, %dK data, %dK init, %dK reserv)\n",
+                PAGES_TO_MB(free_pages),
+                TO_MB(arc_mem_sz),
+                TO_KB(codesize), TO_KB(datasize), TO_KB(initsize),
+                PAGES_TO_KB(reserved_pages));
+}
+
+static void __init free_init_pages(const char *what, unsigned long begin,
+                                   unsigned long end)
+{
+        unsigned long addr;
+
+        pr_info("Freeing %s: %ldk [%lx] to [%lx]\n",
+                what, TO_KB(end - begin), begin, end);
+
+        /* need to check that the page we free is not a partial page */
+        for (addr = begin; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) {
+                ClearPageReserved(virt_to_page(addr));
+                init_page_count(virt_to_page(addr));
+                free_page(addr);
+                totalram_pages++;
+        }
+}
+
+/*
+ * free_initmem: Free all the __init memory.
+ */
+void __init_refok free_initmem(void)
+{
+        free_init_pages("unused kernel memory",
+                        (unsigned long)__init_begin,
+                        (unsigned long)__init_end);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init free_initrd_mem(unsigned long start, unsigned long end)
+{
+        free_init_pages("initrd memory", start, end);
+}
+#endif
diff --git a/arch/arc/plat-arcfpga/platform.c b/arch/arc/plat-arcfpga/platform.c
new file mode 100644
index 000000000000..7b5dcab5becb
--- /dev/null
+++ b/arch/arc/plat-arcfpga/platform.c
@@ -0,0 +1,29 @@
+/*
+ * ARC FPGA Platform support code
+ *
+ * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.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/types.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+
+/*
+ * Early Platform Initialization called from setup_arch()
+ */
+void __init arc_platform_early_init(void)
+{
+        pr_info("[plat-arcfpga]: registering early dev resources\n");
+}
+
+int __init fpga_plat_init(void)
+{
+        pr_info("[plat-arcfpga]: registering device resources\n");
+
+        return 0;
+}
+arch_initcall(fpga_plat_init);