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/* smp.c: Sparc SMP support.

 *

 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)

 */

#include <asm/head.h>

#include <asm/ptrace.h>

#include <linux/kernel.h>

#include <linux/tasks.h>

#include <linux/smp.h>

#include <asm/delay.h>

#include <asm/irq.h>

#include <asm/page.h>

#include <asm/pgtable.h>

#include <asm/oplib.h>

extern ctxd_t *srmmu_ctx_table_phys;

extern int linux_num_cpus;

struct tlog {

        unsigned long pc;

        unsigned long psr;

};

struct tlog trap_log[4][256];

unsigned long trap_log_ent[4] = { 0, 0, 0, 0, };

extern void calibrate_delay(void);

volatile unsigned long stuck_pc = 0;

volatile int smp_processors_ready = 0;

int smp_found_config = 0;

unsigned long cpu_present_map = 0;

int smp_num_cpus = 1;

int smp_threads_ready=0;

unsigned char mid_xlate[NR_CPUS] = { 0, 0, 0, 0, };

volatile unsigned long cpu_callin_map[NR_CPUS] = {0,};

volatile unsigned long smp_invalidate_needed[NR_CPUS] = { 0, };

volatile unsigned long smp_spinning[NR_CPUS] = { 0, };

struct cpuinfo_sparc cpu_data[NR_CPUS];

unsigned char boot_cpu_id = 0;

static int smp_activated = 0;

static volatile unsigned char smp_cpu_in_msg[NR_CPUS];

static volatile unsigned long smp_msg_data;

static volatile int smp_src_cpu;

static volatile int smp_msg_id;

volatile int cpu_number_map[NR_CPUS];

volatile int cpu_logical_map[NR_CPUS];

/* The only guaranteed locking primitive available on all Sparc

 * processors is 'ldstub [%reg + immediate], %dest_reg' which atomically

 * places the current byte at the effective address into dest_reg and

 * places 0xff there afterwards.  Pretty lame locking primitive

 * compared to the Alpha and the intel no?  Most Sparcs have 'swap'

 * instruction which is much better...

 */

klock_t kernel_flag = KLOCK_CLEAR;

volatile unsigned char active_kernel_processor = NO_PROC_ID;

volatile unsigned long kernel_counter = 0;

volatile unsigned long syscall_count = 0;

volatile unsigned long ipi_count;

#ifdef __SMP_PROF__

volatile unsigned long smp_spins[NR_CPUS]={0};

volatile unsigned long smp_spins_syscall[NR_CPUS]={0};

volatile unsigned long smp_spins_syscall_cur[NR_CPUS]={0};

volatile unsigned long smp_spins_sys_idle[NR_CPUS]={0};

volatile unsigned long smp_idle_count[1+NR_CPUS]={0,};

#endif

#if defined (__SMP_PROF__)

volatile unsigned long smp_idle_map=0;

#endif

volatile unsigned long smp_proc_in_lock[NR_CPUS] = {0,};

volatile int smp_process_available=0;

/*#define SMP_DEBUG*/

#ifdef SMP_DEBUG

#define SMP_PRINTK(x)   printk x

#else

#define SMP_PRINTK(x)

#endif

static volatile int smp_commenced = 0;

static char smp_buf[512];

char *smp_info(void)

{

        sprintf(smp_buf,

"\n        CPU0\t\tCPU1\t\tCPU2\t\tCPU3\n"

"State: %s\t\t%s\t\t%s\t\t%s\n"

"Lock:  %08lx\t\t%08lx\t%08lx\t%08lx\n"

"\n"

"klock: %x\n",

                (cpu_present_map & 1) ? ((active_kernel_processor == 0) ? "akp" : "online") : "offline",

                (cpu_present_map & 2) ? ((active_kernel_processor == 1) ? "akp" : "online") : "offline",

                (cpu_present_map & 4) ? ((active_kernel_processor == 2) ? "akp" : "online") : "offline",

                (cpu_present_map & 8) ? ((active_kernel_processor == 3) ? "akp" : "online") : "offline",

                smp_proc_in_lock[0], smp_proc_in_lock[1], smp_proc_in_lock[2],

                smp_proc_in_lock[3],

                kernel_flag);

        return smp_buf;

}

static inline unsigned long swap(volatile unsigned long *ptr, unsigned long val)

{

        __asm__ __volatile__("swap [%1], %0\n\t" :

                             "=&r" (val), "=&r" (ptr) :

                             "0" (val), "1" (ptr));

        return val;

}

/*

 *      The bootstrap kernel entry code has set these up. Save them for

 *      a given CPU

 */

void smp_store_cpu_info(int id)

{

        cpu_data[id].udelay_val = loops_per_sec; /* this is it on sparc. */

}

/*

 *      Architecture specific routine called by the kernel just before init is

 *      fired off. This allows the BP to have everything in order [we hope].

 *      At the end of this all the AP's will hit the system scheduling and off

 *      we go. Each AP will load the system gdt's and jump through the kernel

 *      init into idle(). At this point the scheduler will one day take over

 *      and give them jobs to do. smp_callin is a standard routine

 *      we use to track CPU's as they power up.

 */

void smp_commence(void)

{

        /*

         *      Lets the callin's below out of their loop.

         */

        local_flush_cache_all();

        local_flush_tlb_all();

        smp_commenced = 1;

        local_flush_cache_all();

        local_flush_tlb_all();

}

void smp_callin(void)

{

        int cpuid = smp_processor_id();

        sti();

        local_flush_cache_all();

        local_flush_tlb_all();

        calibrate_delay();

        smp_store_cpu_info(cpuid);

        local_flush_cache_all();

        local_flush_tlb_all();

        cli();

        /* Allow master to continue. */

        swap((unsigned long *)&cpu_callin_map[cpuid], 1);

        local_flush_cache_all();

        local_flush_tlb_all();

        while(!smp_commenced)

                barrier();

        local_flush_cache_all();

        local_flush_tlb_all();

        /* Fix idle thread fields. */

        current->mm->mmap->vm_page_prot = PAGE_SHARED;

        current->mm->mmap->vm_start = KERNBASE;

        current->mm->mmap->vm_end = init_task.mm->mmap->vm_end;

        local_flush_cache_all();

        local_flush_tlb_all();

        sti();

}

void cpu_panic(void)

{

        printk("CPU[%d]: Returns from cpu_idle!\n", smp_processor_id());

        panic("SMP bolixed\n");

}

/*

 *      Cycle through the processors asking the PROM to start each one.

 */

extern struct prom_cpuinfo linux_cpus[NCPUS];

static struct linux_prom_registers penguin_ctable;

void smp_boot_cpus(void)

{

        int cpucount = 0;

        int i = 0;

        printk("Entering SparclinuxMultiPenguin(SMP) Mode...\n");

        penguin_ctable.which_io = 0;

        penguin_ctable.phys_addr = (char *) srmmu_ctx_table_phys;

        penguin_ctable.reg_size = 0;

        sti();

        cpu_present_map |= (1 << smp_processor_id());

        cpu_present_map = 0;

        for(i=0; i < linux_num_cpus; i++)

                cpu_present_map |= (1<<i);

        for(i=0; i < NR_CPUS; i++)

                cpu_number_map[i] = -1;

        for(i=0; i < NR_CPUS; i++)

                cpu_logical_map[i] = -1;

        mid_xlate[boot_cpu_id] = (linux_cpus[boot_cpu_id].mid & ~8);

        cpu_number_map[boot_cpu_id] = 0;

        cpu_logical_map[0] = boot_cpu_id;

        active_kernel_processor = boot_cpu_id;

        smp_store_cpu_info(boot_cpu_id);

        set_irq_udt(0);

        local_flush_cache_all();

        if(linux_num_cpus == 1)

                return;  /* Not an MP box. */

        for(i = 0; i < NR_CPUS; i++) {

                if(i == boot_cpu_id)

                        continue;

                if(cpu_present_map & (1 << i)) {

                        extern unsigned long sparc_cpu_startup;

                        unsigned long *entry = &sparc_cpu_startup;

                        int timeout;

                        /* See trampoline.S for details... */

                        entry += ((i-1) * 6);

                        /* whirrr, whirrr, whirrrrrrrrr... */

                        printk("Starting CPU %d at %p\n", i, entry);

                        mid_xlate[i] = (linux_cpus[i].mid & ~8);

                        local_flush_cache_all();

                        prom_startcpu(linux_cpus[i].prom_node,

                                      &penguin_ctable, 0, (char *)entry);

                        /* wheee... it's going... */

                        for(timeout = 0; timeout < 5000000; timeout++) {

                                if(cpu_callin_map[i])

                                        break;

                                udelay(100);

                        }

                        if(cpu_callin_map[i]) {

                                /* Another "Red Snapper". */

                                cpucount++;

                                cpu_number_map[i] = i;

                                cpu_logical_map[i] = i;

                        } else {

                                printk("Penguin %d is stuck in the bottle.\n", i);

                        }

                }

                if(!(cpu_callin_map[i])) {

                        cpu_present_map &= ~(1 << i);

                        cpu_number_map[i] = -1;

                }

        }

        local_flush_cache_all();

        if(cpucount == 0) {

                printk("Error: only one Penguin found.\n");

                cpu_present_map = (1 << smp_processor_id());

        } else {

                unsigned long bogosum = 0;

                for(i = 0; i < NR_CPUS; i++) {

                        if(cpu_present_map & (1 << i))

                                bogosum += cpu_data[i].udelay_val;

                }

                printk("Total of %d Penguins activated (%lu.%02lu PenguinMIPS).\n",

                       cpucount + 1,

                       (bogosum + 2500)/500000,

                       ((bogosum + 2500)/5000)%100);

                smp_activated = 1;

                smp_num_cpus = cpucount + 1;

        }

        smp_processors_ready = 1;

}

static inline void send_ipi(unsigned long target_map, int irq)

{

        int i;

        for(i = 0; i < 4; i++) {

                if((1<<i) & target_map)

                        set_cpu_int(mid_xlate[i], irq);

        }

}

/*

 * A non wait message cannot pass data or cpu source info. This current

 * setup is only safe because the kernel lock owner is the only person

 * who can send a message.

 *

 * Wrapping this whole block in a spinlock is not the safe answer either.

 * A processor may get stuck with irq's off waiting to send a message and

 * thus not replying to the person spinning for a reply....

 *

 * In the end invalidate ought to be the NMI and a very very short

 * function (to avoid the old IDE disk problems), and other messages sent

 * with IRQ's enabled in a civilised fashion. That will also boost

 * performance.

 */

static volatile int message_cpu = NO_PROC_ID;

void smp_message_pass(int target, int msg, unsigned long data, int wait)

{

        unsigned long target_map;

        int p = smp_processor_id();

        int irq = 15;

        int i;

        /* Before processors have been placed into their initial

         * patterns do not send messages.

         */

        if(!smp_processors_ready)

                return;

        /* Skip the reschedule if we are waiting to clear a

         * message at this time. The reschedule cannot wait

         * but is not critical.

         */

        if(msg == MSG_RESCHEDULE) {

                irq = 13;

                if(smp_cpu_in_msg[p])

                        return;

        }

        /* Sanity check we don't re-enter this across CPU's. Only the kernel

         * lock holder may send messages. For a STOP_CPU we are bringing the

         * entire box to the fastest halt we can.. A reschedule carries

         * no data and can occur during a flush.. guess what panic

         * I got to notice this bug...

         */

        if(message_cpu != NO_PROC_ID && msg != MSG_STOP_CPU && msg != MSG_RESCHEDULE) {

                printk("CPU #%d: Message pass %d but pass in progress by %d of %d\n",

                      smp_processor_id(),msg,message_cpu, smp_msg_id);

                /* I don't know how to gracefully die so that debugging

                 * this doesn't completely eat up my filesystems...

                 * let's try this...

                 */

                smp_cpu_in_msg[p] = 0; /* In case we come back here... */

                intr_count = 0;        /* and so panic don't barf... */

                smp_swap(&message_cpu, NO_PROC_ID); /* push the store buffer */

                sti();

                printk("spinning, please L1-A, type ctrace and send output to davem\n");

                while(1)

                        barrier();

        }

        smp_swap(&message_cpu, smp_processor_id()); /* store buffers... */

        /* We are busy. */

        smp_cpu_in_msg[p]++;

        /* Reschedule is currently special. */

        if(msg != MSG_RESCHEDULE) {

                smp_src_cpu = p;

                smp_msg_id = msg;

                smp_msg_data = data;

        }

#if 0

        printk("SMP message pass from cpu %d to cpu %d msg %d\n", p, target, msg);

#endif

        /* Set the target requirement. */

        for(i = 0; i < smp_num_cpus; i++)

                swap((unsigned long *) &cpu_callin_map[i], 0);

        if(target == MSG_ALL_BUT_SELF) {

                target_map = (cpu_present_map & ~(1<<p));

                swap((unsigned long *) &cpu_callin_map[p], 1);

        } else if(target == MSG_ALL) {

                target_map = cpu_present_map;

        } else {

                for(i = 0; i < smp_num_cpus; i++)

                        if(i != target)

                                swap((unsigned long *) &cpu_callin_map[i], 1);

                target_map = (1<<target);

        }

        /* Fire it off. */

        send_ipi(target_map, irq);

        switch(wait) {

        case 1:

                for(i = 0; i < smp_num_cpus; i++)

                        while(!cpu_callin_map[i])

                                barrier();

                break;

        case 2:

                for(i = 0; i < smp_num_cpus; i++)

                        while(smp_invalidate_needed[i])

                                barrier();

                break;

        case 3:

                /* For cross calls we hold message_cpu and smp_cpu_in_msg[]

                 * until all processors disperse.  Else we have _big_ problems.

                 */

                return;

        }

        smp_cpu_in_msg[p]--;

        smp_swap(&message_cpu, NO_PROC_ID);

}

struct smp_funcall {

        smpfunc_t func;

        unsigned long arg1;

        unsigned long arg2;

        unsigned long arg3;

        unsigned long arg4;

        unsigned long arg5;

        unsigned long processors_in[NR_CPUS];  /* Set when ipi entered. */

        unsigned long processors_out[NR_CPUS]; /* Set when ipi exited. */

} ccall_info;

/* Returns failure code if for example any of the cpu's failed to respond

 * within a certain timeout period.

 */

#define CCALL_TIMEOUT   5000000 /* enough for initial testing */

/* #define DEBUG_CCALL */

/* Some nice day when we really thread the kernel I'd like to synchronize

 * this with either a broadcast conditional variable, a resource adaptive

 * generic mutex, or a convoy semaphore scheme of some sort.  No reason

 * we can't let multiple processors in here if the appropriate locking

 * is done.  Note that such a scheme assumes we will have a

 * prioritized ipi scheme using different software level irq's.

 */

void smp_cross_call(smpfunc_t func, unsigned long arg1, unsigned long arg2,

                    unsigned long arg3, unsigned long arg4, unsigned long arg5)

{

        unsigned long me = smp_processor_id();

        unsigned long flags;

        int i, timeout;

#ifdef DEBUG_CCALL

        printk("xc%d<", me);

#endif

        if(smp_processors_ready) {

                save_flags(flags); cli();

                if(me != active_kernel_processor)

                        goto cross_call_not_master;

                /* Init function glue. */

                ccall_info.func = func;

                ccall_info.arg1 = arg1;

                ccall_info.arg2 = arg2;

                ccall_info.arg3 = arg3;

                ccall_info.arg4 = arg4;

                ccall_info.arg5 = arg5;

                /* Init receive/complete mapping. */

                for(i = 0; i < smp_num_cpus; i++) {

                        ccall_info.processors_in[i] = 0;

                        ccall_info.processors_out[i] = 0;

                }

                ccall_info.processors_in[me] = 1;

                ccall_info.processors_out[me] = 1;

                /* Fire it off. */

                smp_message_pass(MSG_ALL_BUT_SELF, MSG_CROSS_CALL, 0, 3);

                /* For debugging purposes right now we can timeout

                 * on both callin and callexit.

                 */

                timeout = CCALL_TIMEOUT;

                for(i = 0; i < smp_num_cpus; i++) {

                        while(!ccall_info.processors_in[i] && timeout-- > 0)

                                barrier();

                        if(!ccall_info.processors_in[i])

                                goto procs_time_out;

                }

#ifdef DEBUG_CCALL

                printk("I");

#endif

                /* Run local copy. */

                func(arg1, arg2, arg3, arg4, arg5);

                /* Spin on proc dispersion. */

                timeout = CCALL_TIMEOUT;

                for(i = 0; i < smp_num_cpus; i++) {

                        while(!ccall_info.processors_out[i] && timeout-- > 0)

                                barrier();

                        if(!ccall_info.processors_out[i])

                                goto procs_time_out;

                }

#ifdef DEBUG_CCALL

                printk("O>");

#endif

                /* See wait case 3 in smp_message_pass()... */

                smp_cpu_in_msg[me]--;

                smp_swap(&message_cpu, NO_PROC_ID); /* store buffers... */

                restore_flags(flags);

                return; /* made it... */

procs_time_out:

                printk("smp: Wheee, penguin drops off the bus\n");

                smp_cpu_in_msg[me]--;

                message_cpu = NO_PROC_ID;

                restore_flags(flags);

                return; /* why me... why me... */

        }

        /* Just need to run local copy. */

        func(arg1, arg2, arg3, arg4, arg5);

        return;

cross_call_not_master:

        printk("Cross call initiated by non master cpu\n");

        printk("akp=%x me=%08lx\n", active_kernel_processor, me);

        restore_flags(flags);

        panic("penguin cross call");

}

void smp_flush_cache_all(void)

{ xc0((smpfunc_t) local_flush_cache_all); }

void smp_flush_tlb_all(void)

{ xc0((smpfunc_t) local_flush_tlb_all); }

void smp_flush_cache_mm(struct mm_struct *mm)

{

        if(mm->context != NO_CONTEXT)

                xc1((smpfunc_t) local_flush_cache_mm, (unsigned long) mm);

}

void smp_flush_tlb_mm(struct mm_struct *mm)

{

        if(mm->context != NO_CONTEXT)

                xc1((smpfunc_t) local_flush_tlb_mm, (unsigned long) mm);

}

void smp_flush_cache_range(struct mm_struct *mm, unsigned long start,

                           unsigned long end)

{

        if(mm->context != NO_CONTEXT)

                xc3((smpfunc_t) local_flush_cache_range, (unsigned long) mm,

                    start, end);

}

void smp_flush_tlb_range(struct mm_struct *mm, unsigned long start,

                         unsigned long end)

{

        if(mm->context != NO_CONTEXT)

                xc3((smpfunc_t) local_flush_tlb_range, (unsigned long) mm,

                    start, end);

}

void smp_flush_cache_page(struct vm_area_struct *vma, unsigned long page)

{ xc2((smpfunc_t) local_flush_cache_page, (unsigned long) vma, page); }

void smp_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)

{ xc2((smpfunc_t) local_flush_tlb_page, (unsigned long) vma, page); }

void smp_flush_page_to_ram(unsigned long page)

{ xc1((smpfunc_t) local_flush_page_to_ram, page); }

/* Reschedule call back. */

void smp_reschedule_irq(void)

{

        if(smp_processor_id() != active_kernel_processor)

                panic("SMP Reschedule on CPU #%d, but #%d is active.\n",

                      smp_processor_id(), active_kernel_processor);

        need_resched=1;

}

/* XXX FIXME: this still doesn't work right... XXX */

/* #define DEBUG_CAPTURE */

static volatile unsigned long release = 1;

static volatile int capture_level = 0;

void smp_capture(void)

{

        unsigned long flags;

        if(!smp_activated || !smp_commenced)

                return;

#ifdef DEBUG_CAPTURE

        printk("C<%d>", smp_processor_id());

#endif

        save_flags(flags); cli();

        if(!capture_level) {

                release = 0;

                smp_message_pass(MSG_ALL_BUT_SELF, MSG_CAPTURE, 0, 1);

        }

        capture_level++;

        restore_flags(flags);

}

void smp_release(void)

{

        unsigned long flags;

        int i;

        if(!smp_activated || !smp_commenced)

                return;

#ifdef DEBUG_CAPTURE

        printk("R<%d>", smp_processor_id());

#endif

        save_flags(flags); cli();

        if(!(capture_level - 1)) {

                release = 1;

                for(i = 0; i < smp_num_cpus; i++)

                        while(cpu_callin_map[i])

                                barrier();

        }

        capture_level -= 1;

        restore_flags(flags);

}

/* Park a processor, we must watch for more IPI's to invalidate

 * our cache's and TLB's. And also note we can only wait for

 * "lock-less" IPI's and process those, as a result of such IPI's

 * being non-maskable traps being on is enough to receive them.

 */

/* Message call back. */

void smp_message_irq(void)

{

        int i=smp_processor_id();

        switch(smp_msg_id) {

        case MSG_CROSS_CALL:

                /* Do it to it. */

                ccall_info.processors_in[i] = 1;

                ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,

                                ccall_info.arg4, ccall_info.arg5);

                ccall_info.processors_out[i] = 1;

                break;

                /*

                 *      Halt other CPU's for a panic or reboot

                 */