/*
 *  linux/arch/m32r/kernel/smpboot.c
 *    orig : i386 2.4.10
 *
 *  M32R SMP booting functions
 *
 *  Copyright (c) 2001, 2002, 2003  Hitoshi Yamamoto
 *
 *  Taken from i386 version.
 *        (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
 *        (c) 1998, 1999, 2000 Ingo Molnar <mingo@redhat.com>
 *
 *      Much of the core SMP work is based on previous work by Thomas Radke, to
 *      whom a great many thanks are extended.
 *
 *      Thanks to Intel for making available several different Pentium,
 *      Pentium Pro and Pentium-II/Xeon MP machines.
 *      Original development of Linux SMP code supported by Caldera.
 *
 *      This code is released under the GNU General Public License version 2 or
 *      later.
 *
 *      Fixes
 *              Felix Koop      :       NR_CPUS used properly
 *              Jose Renau      :       Handle single CPU case.
 *              Alan Cox        :       By repeated request
 *                                      8) - Total BogoMIP report.
 *              Greg Wright     :       Fix for kernel stacks panic.
 *              Erich Boleyn    :       MP v1.4 and additional changes.
 *      Matthias Sattler        :       Changes for 2.1 kernel map.
 *      Michel Lespinasse       :       Changes for 2.1 kernel map.
 *      Michael Chastain        :       Change trampoline.S to gnu as.
 *              Alan Cox        :       Dumb bug: 'B' step PPro's are fine
 *              Ingo Molnar     :       Added APIC timers, based on code
 *                                      from Jose Renau
 *              Ingo Molnar     :       various cleanups and rewrites
 *              Tigran Aivazian :       fixed "0.00 in /proc/uptime on SMP" bug.
 *      Maciej W. Rozycki       :       Bits for genuine 82489DX APICs
 *              Martin J. Bligh :       Added support for multi-quad systems
 */

#include <linux/module.h>
#include <linux/cpu.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/irq.h>
#include <linux/bootmem.h>
#include <linux/delay.h>

#include <asm/io.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>

#define DEBUG_SMP
#ifdef DEBUG_SMP
#define Dprintk(x...) printk(x)
#else
#define Dprintk(x...)
#endif

extern cpumask_t cpu_initialized;

/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Data structures and variables                                             */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/

/* Processor that is doing the boot up */
static unsigned int bsp_phys_id = -1;

/* Bitmask of physically existing CPUs */
physid_mask_t phys_cpu_present_map;

cpumask_t cpu_bootout_map;
cpumask_t cpu_bootin_map;
static cpumask_t cpu_callin_map;
cpumask_t cpu_callout_map;
EXPORT_SYMBOL(cpu_callout_map);

/* Per CPU bogomips and other parameters */
struct cpuinfo_m32r cpu_data[NR_CPUS] __cacheline_aligned;

static int cpucount;
static cpumask_t smp_commenced_mask;

extern struct {
        void * spi;
        unsigned short ss;
} stack_start;

/* which physical physical ID maps to which logical CPU number */
static volatile int physid_2_cpu[NR_CPUS];
#define physid_to_cpu(physid)   physid_2_cpu[physid]

/* which logical CPU number maps to which physical ID */
volatile int cpu_2_physid[NR_CPUS];

DEFINE_PER_CPU(int, prof_multiplier) = 1;
DEFINE_PER_CPU(int, prof_old_multiplier) = 1;
DEFINE_PER_CPU(int, prof_counter) = 1;

spinlock_t ipi_lock[NR_IPIS];

static unsigned int calibration_result;

/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Function Prototypes                                                       */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/

void smp_prepare_boot_cpu(void);
void smp_prepare_cpus(unsigned int);
static void init_ipi_lock(void);
static void do_boot_cpu(int);
int __cpu_up(unsigned int);
void smp_cpus_done(unsigned int);

int start_secondary(void *);
static void smp_callin(void);
static void smp_online(void);

static void show_mp_info(int);
static void smp_store_cpu_info(int);
static void show_cpu_info(int);
int setup_profiling_timer(unsigned int);
static void init_cpu_to_physid(void);
static void map_cpu_to_physid(int, int);
static void unmap_cpu_to_physid(int, int);

/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Boot up APs Routines : BSP                                                */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
void __devinit smp_prepare_boot_cpu(void)
{
        bsp_phys_id = hard_smp_processor_id();
        physid_set(bsp_phys_id, phys_cpu_present_map);
        cpu_set(0, cpu_online_map);     /* BSP's cpu_id == 0 */
        cpu_set(0, cpu_callout_map);
        cpu_set(0, cpu_callin_map);

        /*
         * Initialize the logical to physical CPU number mapping
         */
        init_cpu_to_physid();
        map_cpu_to_physid(0, bsp_phys_id);
        current_thread_info()->cpu = 0;
}

/*==========================================================================*
 * Name:         smp_prepare_cpus (old smp_boot_cpus)
 *
 * Description:  This routine boot up APs.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    NONE
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 * 2003-06-24 hy  modify for linux-2.5.69
 *
 *==========================================================================*/
void __init smp_prepare_cpus(unsigned int max_cpus)
{
        int phys_id;
        unsigned long nr_cpu;

        nr_cpu = inl(M32R_FPGA_NUM_OF_CPUS_PORTL);
        if (nr_cpu > NR_CPUS) {
                printk(KERN_INFO "NUM_OF_CPUS reg. value [%ld] > NR_CPU [%d]",
                        nr_cpu, NR_CPUS);
                goto smp_done;
        }
        for (phys_id = 0 ; phys_id < nr_cpu ; phys_id++)
                physid_set(phys_id, phys_cpu_present_map);
#ifndef CONFIG_HOTPLUG_CPU
        init_cpu_present(&cpu_possible_map);
#endif

        show_mp_info(nr_cpu);

        init_ipi_lock();

        /*
         * Setup boot CPU information
         */
        smp_store_cpu_info(0); /* Final full version of the data */

        /*
         * If SMP should be disabled, then really disable it!
         */
        if (!max_cpus) {
                printk(KERN_INFO "SMP mode deactivated by commandline.\n");
                goto smp_done;
        }

        /*
         * Now scan the CPU present map and fire up the other CPUs.
         */
        Dprintk("CPU present map : %lx\n", physids_coerce(phys_cpu_present_map));

        for (phys_id = 0 ; phys_id < NR_CPUS ; phys_id++) {
                /*
                 * Don't even attempt to start the boot CPU!
                 */
                if (phys_id == bsp_phys_id)
                        continue;

                if (!physid_isset(phys_id, phys_cpu_present_map))
                        continue;

                if (max_cpus <= cpucount + 1)
                        continue;

                do_boot_cpu(phys_id);

                /*
                 * Make sure we unmap all failed CPUs
                 */
                if (physid_to_cpu(phys_id) == -1) {
                        physid_clear(phys_id, phys_cpu_present_map);
                        printk("phys CPU#%d not responding - " \
                                "cannot use it.\n", phys_id);
                }
        }

smp_done:
        Dprintk("Boot done.\n");
}

/*
 * init_ipi_lock : Initialize IPI locks.
 */
static void __init init_ipi_lock(void)
{
        int ipi;

        for (ipi = 0 ; ipi < NR_IPIS ; ipi++)
                spin_lock_init(&ipi_lock[ipi]);
}

/*==========================================================================*
 * Name:         do_boot_cpu
 *
 * Description:  This routine boot up one AP.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    phys_id - Target CPU physical ID
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 * 2003-06-24 hy  modify for linux-2.5.69
 *
 *==========================================================================*/
static void __init do_boot_cpu(int phys_id)
{
        struct task_struct *idle;
        unsigned long send_status, boot_status;
        int timeout, cpu_id;

        cpu_id = ++cpucount;

        /*
         * We can't use kernel_thread since we must avoid to
         * reschedule the child.
         */
        idle = fork_idle(cpu_id);
        if (IS_ERR(idle))
                panic("failed fork for CPU#%d.", cpu_id);

        idle->thread.lr = (unsigned long)start_secondary;

        map_cpu_to_physid(cpu_id, phys_id);

        /* So we see what's up   */
        printk("Booting processor %d/%d\n", phys_id, cpu_id);
        stack_start.spi = (void *)idle->thread.sp;
        task_thread_info(idle)->cpu = cpu_id;

        /*
         * Send Startup IPI
         *   1.IPI received by CPU#(phys_id).
         *   2.CPU#(phys_id) enter startup_AP (arch/m32r/kernel/head.S)
         *   3.CPU#(phys_id) enter start_secondary()
         */
        send_status = 0;
        boot_status = 0;

        cpu_set(phys_id, cpu_bootout_map);

        /* Send Startup IPI */
        send_IPI_mask_phys(cpumask_of_cpu(phys_id), CPU_BOOT_IPI, 0);

        Dprintk("Waiting for send to finish...\n");
        timeout = 0;

        /* Wait 100[ms] */
        do {
                Dprintk("+");
                udelay(1000);
                send_status = !cpu_isset(phys_id, cpu_bootin_map);
        } while (send_status && (timeout++ < 100));

        Dprintk("After Startup.\n");

        if (!send_status) {
                /*
                 * allow APs to start initializing.
                 */
                Dprintk("Before Callout %d.\n", cpu_id);
                cpu_set(cpu_id, cpu_callout_map);
                Dprintk("After Callout %d.\n", cpu_id);

                /*
                 * Wait 5s total for a response
                 */
                for (timeout = 0; timeout < 5000; timeout++) {
                        if (cpu_isset(cpu_id, cpu_callin_map))
                                break;  /* It has booted */
                        udelay(1000);
                }

                if (cpu_isset(cpu_id, cpu_callin_map)) {
                        /* number CPUs logically, starting from 1 (BSP is 0) */
                        Dprintk("OK.\n");
                } else {
                        boot_status = 1;
                        printk("Not responding.\n");
                }
        } else
                printk("IPI never delivered???\n");

        if (send_status || boot_status) {
                unmap_cpu_to_physid(cpu_id, phys_id);
                cpu_clear(cpu_id, cpu_callout_map);
                cpu_clear(cpu_id, cpu_callin_map);
                cpu_clear(cpu_id, cpu_initialized);
                cpucount--;
        }
}

int __cpuinit __cpu_up(unsigned int cpu_id)
{
        int timeout;

        cpu_set(cpu_id, smp_commenced_mask);

        /*
         * Wait 5s total for a response
         */
        for (timeout = 0; timeout < 5000; timeout++) {
                if (cpu_isset(cpu_id, cpu_online_map))
                        break;
                udelay(1000);
        }
        if (!cpu_isset(cpu_id, cpu_online_map))
                BUG();

        return 0;
}

void __init smp_cpus_done(unsigned int max_cpus)
{
        int cpu_id, timeout;
        unsigned long bogosum = 0;

        for (timeout = 0; timeout < 5000; timeout++) {
                if (cpus_equal(cpu_callin_map, cpu_online_map))
                        break;
                udelay(1000);
        }
        if (!cpus_equal(cpu_callin_map, cpu_online_map))
                BUG();

        for (cpu_id = 0 ; cpu_id < num_online_cpus() ; cpu_id++)
                show_cpu_info(cpu_id);

        /*
         * Allow the user to impress friends.
         */
        Dprintk("Before bogomips.\n");
        if (cpucount) {
                for_each_cpu_mask(cpu_id, cpu_online_map)
                        bogosum += cpu_data[cpu_id].loops_per_jiffy;

                printk(KERN_INFO "Total of %d processors activated " \
                        "(%lu.%02lu BogoMIPS).\n", cpucount + 1,
                        bogosum / (500000 / HZ),
                        (bogosum / (5000 / HZ)) % 100);
                Dprintk("Before bogocount - setting activated=1.\n");
        }
}

/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Activate a secondary processor Routines                                   */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/

/*==========================================================================*
 * Name:         start_secondary
 *
 * Description:  This routine activate a secondary processor.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    *unused - currently unused.
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 * 2003-06-24 hy  modify for linux-2.5.69
 *
 *==========================================================================*/
int __init start_secondary(void *unused)
{
        cpu_init();
        preempt_disable();
        smp_callin();
        while (!cpu_isset(smp_processor_id(), smp_commenced_mask))
                cpu_relax();

        smp_online();

        /*
         * low-memory mappings have been cleared, flush them from
         * the local TLBs too.
         */
        local_flush_tlb_all();

        cpu_idle();
        return 0;
}

/*==========================================================================*
 * Name:         smp_callin
 *
 * Description:  This routine activate a secondary processor.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    NONE
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 * 2003-06-24 hy  modify for linux-2.5.69
 *
 *==========================================================================*/
static void __init smp_callin(void)
{
        int phys_id = hard_smp_processor_id();
        int cpu_id = smp_processor_id();
        unsigned long timeout;

        if (cpu_isset(cpu_id, cpu_callin_map)) {
                printk("huh, phys CPU#%d, CPU#%d already present??\n",
                        phys_id, cpu_id);
                BUG();
        }
        Dprintk("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpu_id, phys_id);

        /* Waiting 2s total for startup (udelay is not yet working) */
        timeout = jiffies + (2 * HZ);
        while (time_before(jiffies, timeout)) {
                /* Has the boot CPU finished it's STARTUP sequence ? */
                if (cpu_isset(cpu_id, cpu_callout_map))
                        break;
                cpu_relax();
        }

        if (!time_before(jiffies, timeout)) {
                printk("BUG: CPU#%d started up but did not get a callout!\n",
                        cpu_id);
                BUG();
        }

        /* Allow the master to continue. */
        cpu_set(cpu_id, cpu_callin_map);
}

static void __init smp_online(void)
{
        int cpu_id = smp_processor_id();

        notify_cpu_starting(cpu_id);

        local_irq_enable();

        /* Get our bogomips. */
        calibrate_delay();

        /* Save our processor parameters */
        smp_store_cpu_info(cpu_id);

        cpu_set(cpu_id, cpu_online_map);
}

/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Boot up CPUs common Routines                                              */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
static void __init show_mp_info(int nr_cpu)
{
        int i;
        char cpu_model0[17], cpu_model1[17], cpu_ver[9];

        strncpy(cpu_model0, (char *)M32R_FPGA_CPU_NAME_ADDR, 16);
        strncpy(cpu_model1, (char *)M32R_FPGA_MODEL_ID_ADDR, 16);
        strncpy(cpu_ver, (char *)M32R_FPGA_VERSION_ADDR, 8);

        cpu_model0[16] = '\0';
        for (i = 15 ; i >= 0 ; i--) {
                if (cpu_model0[i] != ' ')
                        break;
                cpu_model0[i] = '\0';
        }
        cpu_model1[16] = '\0';
        for (i = 15 ; i >= 0 ; i--) {
                if (cpu_model1[i] != ' ')
                        break;
                cpu_model1[i] = '\0';
        }
        cpu_ver[8] = '\0';
        for (i = 7 ; i >= 0 ; i--) {
                if (cpu_ver[i] != ' ')
                        break;
                cpu_ver[i] = '\0';
        }

        printk(KERN_INFO "M32R-mp information\n");
        printk(KERN_INFO "  On-chip CPUs : %d\n", nr_cpu);
        printk(KERN_INFO "  CPU model : %s/%s(%s)\n", cpu_model0,
                cpu_model1, cpu_ver);
}

/*
 * The bootstrap kernel entry code has set these up. Save them for
 * a given CPU
 */
static void __init smp_store_cpu_info(int cpu_id)
{
        struct cpuinfo_m32r *ci = cpu_data + cpu_id;

        *ci = boot_cpu_data;
        ci->loops_per_jiffy = loops_per_jiffy;
}

static void __init show_cpu_info(int cpu_id)
{
        struct cpuinfo_m32r *ci = &cpu_data[cpu_id];

        printk("CPU#%d : ", cpu_id);

#define PRINT_CLOCK(name, value) \
        printk(name " clock %d.%02dMHz", \
                ((value) / 1000000), ((value) % 1000000) / 10000)

        PRINT_CLOCK("CPU", (int)ci->cpu_clock);
        PRINT_CLOCK(", Bus", (int)ci->bus_clock);
        printk(", loops_per_jiffy[%ld]\n", ci->loops_per_jiffy);
}

/*
 * the frequency of the profiling timer can be changed
 * by writing a multiplier value into /proc/profile.
 */
int setup_profiling_timer(unsigned int multiplier)
{
        int i;

        /*
         * Sanity check. [at least 500 APIC cycles should be
         * between APIC interrupts as a rule of thumb, to avoid
         * irqs flooding us]
         */
        if ( (!multiplier) || (calibration_result / multiplier < 500))
                return -EINVAL;

        /*
         * Set the new multiplier for each CPU. CPUs don't start using the
         * new values until the next timer interrupt in which they do process
         * accounting. At that time they also adjust their APIC timers
         * accordingly.
         */
        for_each_possible_cpu(i)
                per_cpu(prof_multiplier, i) = multiplier;

        return 0;
}

/* Initialize all maps between cpu number and apicids */
static void __init init_cpu_to_physid(void)
{
        int  i;

        for (i = 0 ; i < NR_CPUS ; i++) {
                cpu_2_physid[i] = -1;
                physid_2_cpu[i] = -1;
        }
}

/*
 * set up a mapping between cpu and apicid. Uses logical apicids for multiquad,
 * else physical apic ids
 */
static void __init map_cpu_to_physid(int cpu_id, int phys_id)
{
        physid_2_cpu[phys_id] = cpu_id;
        cpu_2_physid[cpu_id] = phys_id;
}

/*
 * undo a mapping between cpu and apicid. Uses logical apicids for multiquad,
 * else physical apic ids
 */
static void __init unmap_cpu_to_physid(int cpu_id, int phys_id)
{
        physid_2_cpu[phys_id] = -1;
        cpu_2_physid[cpu_id] = -1;
}