setup.c

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/*
 * linux/arch/unicore32/kernel/setup.c
 *
 * Code specific to PKUnity SoC and UniCore ISA
 *
 * Copyright (C) 2001-2010 GUAN Xue-tao
 *
 * 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/module.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/utsname.h>
#include <linux/initrd.h>
#include <linux/console.h>
#include <linux/bootmem.h>
#include <linux/seq_file.h>
#include <linux/screen_info.h>
#include <linux/init.h>
#include <linux/root_dev.h>
#include <linux/cpu.h>
#include <linux/interrupt.h>
#include <linux/smp.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/memblock.h>
#include <linux/elf.h>
#include <linux/io.h>

#include <asm/cputype.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/traps.h>
#include <asm/memblock.h>

#include "setup.h"

#ifndef MEM_SIZE
#define MEM_SIZE    (16*1024*1024)
#endif

struct stack {
    u32 irq[3];
    u32 abt[3];
    u32 und[3];
} ____cacheline_aligned;

static struct stack stacks[NR_CPUS];

char elf_platform[ELF_PLATFORM_SIZE];
EXPORT_SYMBOL(elf_platform);

static char __initdata cmd_line[COMMAND_LINE_SIZE];

static char default_command_line[COMMAND_LINE_SIZE] __initdata = CONFIG_CMDLINE;

/*
 * Standard memory resources
 */
static struct resource mem_res[] = {
    {
        .name = "Kernel code",
        .start = 0,
        .end = 0,
        .flags = IORESOURCE_MEM
    },
    {
        .name = "Kernel data",
        .start = 0,
        .end = 0,
        .flags = IORESOURCE_MEM
    }
};

#define kernel_code mem_res[0]
#define kernel_data mem_res[1]

/*
 * These functions re-use the assembly code in head.S, which
 * already provide the required functionality.
 */
static void __init setup_processor(void)
{
    printk(KERN_DEFAULT "CPU: UniCore-II [%08x] revision %d, cr=%08lx\n",
           uc32_cpuid, (int)(uc32_cpuid >> 16) & 15, cr_alignment);

    sprintf(init_utsname()->machine, "puv3");
    sprintf(elf_platform, "ucv2");
}

/*
 * cpu_init - initialise one CPU.
 *
 * cpu_init sets up the per-CPU stacks.
 */
void cpu_init(void)
{
    unsigned int cpu = smp_processor_id();
    struct stack *stk = &stacks[cpu];

    /*
     * setup stacks for re-entrant exception handlers
     */
    __asm__ (
    "mov.a  asr, %1\n\t"
    "add    sp, %0, %2\n\t"
    "mov.a  asr, %3\n\t"
    "add    sp, %0, %4\n\t"
    "mov.a  asr, %5\n\t"
    "add    sp, %0, %6\n\t"
    "mov.a  asr, %7"
        :
        : "r" (stk),
          "r" (PSR_R_BIT | PSR_I_BIT | INTR_MODE),
          "I" (offsetof(struct stack, irq[0])),
          "r" (PSR_R_BIT | PSR_I_BIT | ABRT_MODE),
          "I" (offsetof(struct stack, abt[0])),
          "r" (PSR_R_BIT | PSR_I_BIT | EXTN_MODE),
          "I" (offsetof(struct stack, und[0])),
          "r" (PSR_R_BIT | PSR_I_BIT | PRIV_MODE)
    : "r30", "cc");
}

static int __init uc32_add_memory(unsigned long start, unsigned long size)
{
    struct membank *bank = &meminfo.bank[meminfo.nr_banks];

    if (meminfo.nr_banks >= NR_BANKS) {
        printk(KERN_CRIT "NR_BANKS too low, "
            "ignoring memory at %#lx\n", start);
        return -EINVAL;
    }

    /*
     * Ensure that start/size are aligned to a page boundary.
     * Size is appropriately rounded down, start is rounded up.
     */
    size -= start & ~PAGE_MASK;

    bank->start = PAGE_ALIGN(start);
    bank->size  = size & PAGE_MASK;

    /*
     * Check whether this memory region has non-zero size or
     * invalid node number.
     */
    if (bank->size == 0)
        return -EINVAL;

    meminfo.nr_banks++;
    return 0;
}

/*
 * Pick out the memory size.  We look for mem=size@start,
 * where start and size are "size[KkMm]"
 */
static int __init early_mem(char *p)
{
    static int usermem __initdata = 1;
    unsigned long size, start;
    char *endp;

    /*
     * If the user specifies memory size, we
     * blow away any automatically generated
     * size.
     */
    if (usermem) {
        usermem = 0;
        meminfo.nr_banks = 0;
    }

    start = PHYS_OFFSET;
    size  = memparse(p, &endp);
    if (*endp == '@')
        start = memparse(endp + 1, NULL);

    uc32_add_memory(start, size);

    return 0;
}
early_param("mem", early_mem);

static void __init
request_standard_resources(struct meminfo *mi)
{
    struct resource *res;
    int i;

    kernel_code.start   = virt_to_phys(_stext);
    kernel_code.end     = virt_to_phys(_etext - 1);
    kernel_data.start   = virt_to_phys(_sdata);
    kernel_data.end     = virt_to_phys(_end - 1);

    for (i = 0; i < mi->nr_banks; i++) {
        if (mi->bank[i].size == 0)
            continue;

        res = alloc_bootmem_low(sizeof(*res));
        res->name  = "System RAM";
        res->start = mi->bank[i].start;
        res->end   = mi->bank[i].start + mi->bank[i].size - 1;
        res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;

        request_resource(&iomem_resource, res);

        if (kernel_code.start >= res->start &&
            kernel_code.end <= res->end)
            request_resource(res, &kernel_code);
        if (kernel_data.start >= res->start &&
            kernel_data.end <= res->end)
            request_resource(res, &kernel_data);
    }
}

static void (*init_machine)(void) __initdata;

static int __init customize_machine(void)
{
    /* customizes platform devices, or adds new ones */
    if (init_machine)
        init_machine();
    return 0;
}
arch_initcall(customize_machine);

void __init setup_arch(char **cmdline_p)
{
    char *from = default_command_line;

    setup_processor();

    init_mm.start_code = (unsigned long) _stext;
    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;

    parse_early_param();

    uc32_memblock_init(&meminfo);

    paging_init();
    request_standard_resources(&meminfo);

    cpu_init();

    /*
     * Set up various architecture-specific pointers
     */
    init_machine = puv3_core_init;

#ifdef CONFIG_VT
#if defined(CONFIG_VGA_CONSOLE)
    conswitchp = &vga_con;
#elif defined(CONFIG_DUMMY_CONSOLE)
    conswitchp = &dummy_con;
#endif
#endif
    early_trap_init();
}

static struct cpu cpuinfo_unicore;

static int __init topology_init(void)
{
    int i;

    for_each_possible_cpu(i)
        register_cpu(&cpuinfo_unicore, i);

    return 0;
}
subsys_initcall(topology_init);

#ifdef CONFIG_HAVE_PROC_CPU
static int __init proc_cpu_init(void)
{
    struct proc_dir_entry *res;

    res = proc_mkdir("cpu", NULL);
    if (!res)
        return -ENOMEM;
    return 0;
}
fs_initcall(proc_cpu_init);
#endif

static int c_show(struct seq_file *m, void *v)
{
    seq_printf(m, "Processor\t: UniCore-II rev %d (%s)\n",
           (int)(uc32_cpuid >> 16) & 15, elf_platform);

    seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
           loops_per_jiffy / (500000/HZ),
           (loops_per_jiffy / (5000/HZ)) % 100);

    /* dump out the processor features */
    seq_puts(m, "Features\t: CMOV UC-F64");

    seq_printf(m, "\nCPU implementer\t: 0x%02x\n", uc32_cpuid >> 24);
    seq_printf(m, "CPU architecture: 2\n");
    seq_printf(m, "CPU revision\t: %d\n", (uc32_cpuid >> 16) & 15);

    seq_printf(m, "Cache type\t: write-back\n"
            "Cache clean\t: cp0 c5 ops\n"
            "Cache lockdown\t: not support\n"
            "Cache format\t: Harvard\n");

    seq_puts(m, "\n");

    seq_printf(m, "Hardware\t: PKUnity v3\n");

    return 0;
}

static void *c_start(struct seq_file *m, loff_t *pos)
{
    return *pos < 1 ? (void *)1 : NULL;
}

static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
    ++*pos;
    return NULL;
}

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   = c_show
};