root/arch/sparc/kernel/setup_32.c
// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/arch/sparc/kernel/setup.c
 *
 *  Copyright (C) 1995  David S. Miller (davem@caip.rutgers.edu)
 *  Copyright (C) 2000  Anton Blanchard (anton@samba.org)
 */

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/initrd.h>
#include <asm/smp.h>
#include <linux/user.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/kdev_t.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/console.h>
#include <linux/spinlock.h>
#include <linux/root_dev.h>
#include <linux/cpu.h>
#include <linux/kdebug.h>
#include <linux/export.h>
#include <linux/start_kernel.h>
#include <uapi/linux/mount.h>

#include <asm/io.h>
#include <asm/processor.h>
#include <asm/oplib.h>
#include <asm/page.h>
#include <asm/traps.h>
#include <asm/vaddrs.h>
#include <asm/mbus.h>
#include <asm/idprom.h>
#include <asm/cpudata.h>
#include <asm/setup.h>
#include <asm/cacheflush.h>
#include <asm/sections.h>

#include "kernel.h"

/* Typing sync at the prom prompt calls the function pointed to by
 * romvec->pv_synchook which I set to the following function.
 * This should sync all filesystems and return, for now it just
 * prints out pretty messages and returns.
 */

/* Pretty sick eh? */
static void prom_sync_me(void)
{
        unsigned long prom_tbr, flags;

        /* XXX Badly broken. FIX! - Anton */
        local_irq_save(flags);
        __asm__ __volatile__("rd %%tbr, %0\n\t" : "=r" (prom_tbr));
        __asm__ __volatile__("wr %0, 0x0, %%tbr\n\t"
                             "nop\n\t"
                             "nop\n\t"
                             "nop\n\t" : : "r" (&trapbase[0]));

        prom_printf("PROM SYNC COMMAND...\n");
        show_mem();
        if (!is_idle_task(current)) {
                local_irq_enable();
                ksys_sync();
                local_irq_disable();
        }
        prom_printf("Returning to prom\n");

        __asm__ __volatile__("wr %0, 0x0, %%tbr\n\t"
                             "nop\n\t"
                             "nop\n\t"
                             "nop\n\t" : : "r" (prom_tbr));
        local_irq_restore(flags);
}

static unsigned int boot_flags __initdata = 0;
#define BOOTME_DEBUG  0x1

/* Exported for mm/init.c:paging_init. */
unsigned long cmdline_memory_size __initdata = 0;

/* which CPU booted us (0xff = not set) */
unsigned char boot_cpu_id = 0xff; /* 0xff will make it into DATA section... */

static void
prom_console_write(struct console *con, const char *s, unsigned int n)
{
        prom_write(s, n);
}

static struct console prom_early_console = {
        .name =         "earlyprom",
        .write =        prom_console_write,
        .flags =        CON_PRINTBUFFER | CON_BOOT,
        .index =        -1,
};

/* 
 * Process kernel command line switches that are specific to the
 * SPARC or that require special low-level processing.
 */
static void __init process_switch(char c)
{
        switch (c) {
        case 'd':
                boot_flags |= BOOTME_DEBUG;
                break;
        case 's':
                break;
        case 'h':
                prom_printf("boot_flags_init: Halt!\n");
                prom_halt();
                break;
        case 'p':
                prom_early_console.flags &= ~CON_BOOT;
                break;
        default:
                printk("Unknown boot switch (-%c)\n", c);
                break;
        }
}

static void __init boot_flags_init(char *commands)
{
        while (*commands) {
                /* Move to the start of the next "argument". */
                while (*commands == ' ')
                        commands++;

                /* Process any command switches, otherwise skip it. */
                if (*commands == '\0')
                        break;
                if (*commands == '-') {
                        commands++;
                        while (*commands && *commands != ' ')
                                process_switch(*commands++);
                        continue;
                }
                if (!strncmp(commands, "mem=", 4)) {
                        /*
                         * "mem=XXX[kKmM] overrides the PROM-reported
                         * memory size.
                         */
                        cmdline_memory_size = simple_strtoul(commands + 4,
                                                     &commands, 0);
                        if (*commands == 'K' || *commands == 'k') {
                                cmdline_memory_size <<= 10;
                                commands++;
                        } else if (*commands=='M' || *commands=='m') {
                                cmdline_memory_size <<= 20;
                                commands++;
                        }
                }
                while (*commands && *commands != ' ')
                        commands++;
        }
}

extern unsigned short root_flags;
extern unsigned short root_dev;
extern unsigned short ram_flags;
#define RAMDISK_IMAGE_START_MASK        0x07FF
#define RAMDISK_PROMPT_FLAG             0x8000
#define RAMDISK_LOAD_FLAG               0x4000

extern int root_mountflags;

char reboot_command[COMMAND_LINE_SIZE];

struct cpuid_patch_entry {
        unsigned int    addr;
        unsigned int    sun4d[3];
        unsigned int    leon[3];
};
extern struct cpuid_patch_entry __cpuid_patch, __cpuid_patch_end;

static void __init per_cpu_patch(void)
{
        struct cpuid_patch_entry *p;

        if (sparc_cpu_model == sun4m) {
                /* Nothing to do, this is what the unpatched code
                 * targets.
                 */
                return;
        }

        p = &__cpuid_patch;
        while (p < &__cpuid_patch_end) {
                unsigned long addr = p->addr;
                unsigned int *insns;

                switch (sparc_cpu_model) {
                case sun4d:
                        insns = &p->sun4d[0];
                        break;

                case sparc_leon:
                        insns = &p->leon[0];
                        break;
                default:
                        prom_printf("Unknown cpu type, halting.\n");
                        prom_halt();
                }
                *(unsigned int *) (addr + 0) = insns[0];
                flushi(addr + 0);
                *(unsigned int *) (addr + 4) = insns[1];
                flushi(addr + 4);
                *(unsigned int *) (addr + 8) = insns[2];
                flushi(addr + 8);

                p++;
        }
}

struct leon_1insn_patch_entry {
        unsigned int addr;
        unsigned int insn;
};

enum sparc_cpu sparc_cpu_model;
EXPORT_SYMBOL(sparc_cpu_model);

static __init void leon_patch(void)
{
        struct leon_1insn_patch_entry *start = (void *)__leon_1insn_patch;
        struct leon_1insn_patch_entry *end = (void *)__leon_1insn_patch_end;

        /* Default instruction is leon - no patching */
        if (sparc_cpu_model == sparc_leon)
                return;

        while (start < end) {
                unsigned long addr = start->addr;

                *(unsigned int *)(addr) = start->insn;
                flushi(addr);

                start++;
        }
}

struct tt_entry *sparc_ttable;

/* Called from head_32.S - before we have setup anything
 * in the kernel. Be very careful with what you do here.
 */
void __init sparc32_start_kernel(struct linux_romvec *rp)
{
        prom_init(rp);

        /* Set sparc_cpu_model */
        sparc_cpu_model = sun_unknown;
        if (!strcmp(&cputypval[0], "sun4m"))
                sparc_cpu_model = sun4m;
        if (!strcmp(&cputypval[0], "sun4s"))
                sparc_cpu_model = sun4m; /* CP-1200 with PROM 2.30 -E */
        if (!strcmp(&cputypval[0], "sun4d"))
                sparc_cpu_model = sun4d;
        if (!strcmp(&cputypval[0], "sun4e"))
                sparc_cpu_model = sun4e;
        if (!strcmp(&cputypval[0], "sun4u"))
                sparc_cpu_model = sun4u;
        if (!strncmp(&cputypval[0], "leon" , 4))
                sparc_cpu_model = sparc_leon;

        leon_patch();
        start_kernel();
}

void __init setup_arch(char **cmdline_p)
{
        int i;
        unsigned long highest_paddr;

        sparc_ttable = &trapbase[0];

        /* Initialize PROM console and command line. */
        *cmdline_p = prom_getbootargs();
        strscpy(boot_command_line, *cmdline_p, COMMAND_LINE_SIZE);
        parse_early_param();

        boot_flags_init(*cmdline_p);

        register_console(&prom_early_console);

        switch(sparc_cpu_model) {
        case sun4m:
                pr_info("ARCH: SUN4M\n");
                break;
        case sun4d:
                pr_info("ARCH: SUN4D\n");
                break;
        case sun4e:
                pr_info("ARCH: SUN4E\n");
                break;
        case sun4u:
                pr_info("ARCH: SUN4U\n");
                break;
        case sparc_leon:
                pr_info("ARCH: LEON\n");
                break;
        default:
                pr_info("ARCH: UNKNOWN!\n");
                break;
        }

        idprom_init();
        load_mmu();

        phys_base = 0xffffffffUL;
        highest_paddr = 0UL;
        for (i = 0; sp_banks[i].num_bytes != 0; i++) {
                unsigned long top;

                if (sp_banks[i].base_addr < phys_base)
                        phys_base = sp_banks[i].base_addr;
                top = sp_banks[i].base_addr +
                        sp_banks[i].num_bytes;
                if (highest_paddr < top)
                        highest_paddr = top;
        }
        pfn_base = phys_base >> PAGE_SHIFT;

        if (!root_flags)
                root_mountflags &= ~MS_RDONLY;
        ROOT_DEV = old_decode_dev(root_dev);
#ifdef CONFIG_BLK_DEV_RAM
        rd_image_start = ram_flags & RAMDISK_IMAGE_START_MASK;
#endif

        prom_setsync(prom_sync_me);

        if((boot_flags & BOOTME_DEBUG) && (linux_dbvec != NULL) &&
           ((*(short *)linux_dbvec) != -1)) {
                printk("Booted under KADB. Syncing trap table.\n");
                (*(linux_dbvec->teach_debugger))();
        }

        /* Run-time patch instructions to match the cpu model */
        per_cpu_patch();

        paging_init();

        smp_setup_cpu_possible_map();
}

extern int stop_a_enabled;

void sun_do_break(void)
{
        if (!stop_a_enabled)
                return;

        printk("\n");
        flush_user_windows();

        prom_cmdline();
}
EXPORT_SYMBOL(sun_do_break);

int stop_a_enabled = 1;

static int __init topology_init(void)
{
        int i, ncpus, err;

        /* Count the number of physically present processors in
         * the machine, even on uniprocessor, so that /proc/cpuinfo
         * output is consistent with 2.4.x
         */
        ncpus = 0;
        while (!cpu_find_by_instance(ncpus, NULL, NULL))
                ncpus++;
        ncpus_probed = ncpus;

        err = 0;
        for_each_online_cpu(i) {
                struct cpu *p = kzalloc_obj(*p);
                if (!p)
                        err = -ENOMEM;
                else
                        register_cpu(p, i);
        }

        return err;
}

subsys_initcall(topology_init);

#if defined(CONFIG_SPARC32) && !defined(CONFIG_SMP)
void __init arch_cpu_finalize_init(void)
{
        cpu_data(0).udelay_val = loops_per_jiffy;
}
#endif