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linux/arch/sparc64/kernel/smp.c
David S. Miller 4f07118f65 [SPARC64]: More fully work around Spitfire Errata 51. 
It appears that a memory barrier soon after a mispredicted
branch, not just in the delay slot, can cause the hang
condition of this cpu errata.

So move them out-of-line, and explicitly put them into
a "branch always, predict taken" delay slot which should
fully kill this problem.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 12:46:22 -07:00

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/* smp.c: Sparc64 SMP support.
*
* Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/threads.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/cache.h>
#include <linux/jiffies.h>
#include <linux/profile.h>
#include <linux/bootmem.h>
#include <asm/head.h>
#include <asm/ptrace.h>
#include <asm/atomic.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
#include <asm/cpudata.h>
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/oplib.h>
#include <asm/uaccess.h>
#include <asm/timer.h>
#include <asm/starfire.h>
#include <asm/tlb.h>
extern int linux_num_cpus;
extern void calibrate_delay(void);
/* Please don't make this stuff initdata!!! --DaveM */
static unsigned char boot_cpu_id;
cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE;
cpumask_t phys_cpu_present_map __read_mostly = CPU_MASK_NONE;
static cpumask_t smp_commenced_mask;
static cpumask_t cpu_callout_map;
void smp_info(struct seq_file *m)
{
int i;
seq_printf(m, "State:\n");
for (i = 0; i < NR_CPUS; i++) {
if (cpu_online(i))
seq_printf(m,
"CPU%d:\t\tonline\n", i);
}
}
void smp_bogo(struct seq_file *m)
{
int i;
for (i = 0; i < NR_CPUS; i++)
if (cpu_online(i))
seq_printf(m,
"Cpu%dBogo\t: %lu.%02lu\n"
"Cpu%dClkTck\t: %016lx\n",
i, cpu_data(i).udelay_val / (500000/HZ),
(cpu_data(i).udelay_val / (5000/HZ)) % 100,
i, cpu_data(i).clock_tick);
}
void __init smp_store_cpu_info(int id)
{
int cpu_node;
/* multiplier and counter set by
smp_setup_percpu_timer() */
cpu_data(id).udelay_val = loops_per_jiffy;
cpu_find_by_mid(id, &cpu_node);
cpu_data(id).clock_tick = prom_getintdefault(cpu_node,
"clock-frequency", 0);
cpu_data(id).pgcache_size = 0;
cpu_data(id).pte_cache[0] = NULL;
cpu_data(id).pte_cache[1] = NULL;
cpu_data(id).pgd_cache = NULL;
cpu_data(id).idle_volume = 1;
}
static void smp_setup_percpu_timer(void);
static volatile unsigned long callin_flag = 0;
extern void inherit_locked_prom_mappings(int save_p);
static inline void cpu_setup_percpu_base(unsigned long cpu_id)
{
__asm__ __volatile__("mov %0, %%g5\n\t"
"stxa %0, [%1] %2\n\t"
"membar #Sync"
: /* no outputs */
: "r" (__per_cpu_offset(cpu_id)),
"r" (TSB_REG), "i" (ASI_IMMU));
}
void __init smp_callin(void)
{
int cpuid = hard_smp_processor_id();
inherit_locked_prom_mappings(0);
__flush_tlb_all();
cpu_setup_percpu_base(cpuid);
smp_setup_percpu_timer();
if (cheetah_pcache_forced_on)
cheetah_enable_pcache();
local_irq_enable();
calibrate_delay();
smp_store_cpu_info(cpuid);
callin_flag = 1;
__asm__ __volatile__("membar #Sync\n\t"
"flush %%g6" : : : "memory");
/* Clear this or we will die instantly when we
* schedule back to this idler...
*/
current_thread_info()->new_child = 0;
/* Attach to the address space of init_task. */
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
while (!cpu_isset(cpuid, smp_commenced_mask))
rmb();
cpu_set(cpuid, cpu_online_map);
}
void cpu_panic(void)
{
printk("CPU[%d]: Returns from cpu_idle!\n", smp_processor_id());
panic("SMP bolixed\n");
}
static unsigned long current_tick_offset __read_mostly;
/* This tick register synchronization scheme is taken entirely from
* the ia64 port, see arch/ia64/kernel/smpboot.c for details and credit.
*
* The only change I've made is to rework it so that the master
* initiates the synchonization instead of the slave. -DaveM
*/
#define MASTER 0
#define SLAVE (SMP_CACHE_BYTES/sizeof(unsigned long))
#define NUM_ROUNDS 64 /* magic value */
#define NUM_ITERS 5 /* likewise */
static DEFINE_SPINLOCK(itc_sync_lock);
static unsigned long go[SLAVE + 1];
#define DEBUG_TICK_SYNC 0
static inline long get_delta (long *rt, long *master)
{
unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
unsigned long tcenter, t0, t1, tm;
unsigned long i;
for (i = 0; i < NUM_ITERS; i++) {
t0 = tick_ops->get_tick();
go[MASTER] = 1;
membar_storeload();
while (!(tm = go[SLAVE]))
rmb();
go[SLAVE] = 0;
wmb();
t1 = tick_ops->get_tick();
if (t1 - t0 < best_t1 - best_t0)
best_t0 = t0, best_t1 = t1, best_tm = tm;
}
*rt = best_t1 - best_t0;
*master = best_tm - best_t0;
/* average best_t0 and best_t1 without overflow: */
tcenter = (best_t0/2 + best_t1/2);
if (best_t0 % 2 + best_t1 % 2 == 2)
tcenter++;
return tcenter - best_tm;
}
void smp_synchronize_tick_client(void)
{
long i, delta, adj, adjust_latency = 0, done = 0;
unsigned long flags, rt, master_time_stamp, bound;
#if DEBUG_TICK_SYNC
struct {
long rt; /* roundtrip time */
long master; /* master's timestamp */
long diff; /* difference between midpoint and master's timestamp */
long lat; /* estimate of itc adjustment latency */
} t[NUM_ROUNDS];
#endif
go[MASTER] = 1;
while (go[MASTER])
rmb();
local_irq_save(flags);
{
for (i = 0; i < NUM_ROUNDS; i++) {
delta = get_delta(&rt, &master_time_stamp);
if (delta == 0) {
done = 1; /* let's lock on to this... */
bound = rt;
}
if (!done) {
if (i > 0) {
adjust_latency += -delta;
adj = -delta + adjust_latency/4;
} else
adj = -delta;
tick_ops->add_tick(adj, current_tick_offset);
}
#if DEBUG_TICK_SYNC
t[i].rt = rt;
t[i].master = master_time_stamp;
t[i].diff = delta;
t[i].lat = adjust_latency/4;
#endif
}
}
local_irq_restore(flags);
#if DEBUG_TICK_SYNC
for (i = 0; i < NUM_ROUNDS; i++)
printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
t[i].rt, t[i].master, t[i].diff, t[i].lat);
#endif
printk(KERN_INFO "CPU %d: synchronized TICK with master CPU (last diff %ld cycles,"
"maxerr %lu cycles)\n", smp_processor_id(), delta, rt);
}
static void smp_start_sync_tick_client(int cpu);
static void smp_synchronize_one_tick(int cpu)
{
unsigned long flags, i;
go[MASTER] = 0;
smp_start_sync_tick_client(cpu);
/* wait for client to be ready */
while (!go[MASTER])
rmb();
/* now let the client proceed into his loop */
go[MASTER] = 0;
membar_storeload();
spin_lock_irqsave(&itc_sync_lock, flags);
{
for (i = 0; i < NUM_ROUNDS*NUM_ITERS; i++) {
while (!go[MASTER])
rmb();
go[MASTER] = 0;
wmb();
go[SLAVE] = tick_ops->get_tick();
membar_storeload();
}
}
spin_unlock_irqrestore(&itc_sync_lock, flags);
}
extern unsigned long sparc64_cpu_startup;
/* The OBP cpu startup callback truncates the 3rd arg cookie to
* 32-bits (I think) so to be safe we have it read the pointer
* contained here so we work on >4GB machines. -DaveM
*/
static struct thread_info *cpu_new_thread = NULL;
static int __devinit smp_boot_one_cpu(unsigned int cpu)
{
unsigned long entry =
(unsigned long)(&sparc64_cpu_startup);
unsigned long cookie =
(unsigned long)(&cpu_new_thread);
struct task_struct *p;
int timeout, ret, cpu_node;
p = fork_idle(cpu);
callin_flag = 0;
cpu_new_thread = p->thread_info;
cpu_set(cpu, cpu_callout_map);
cpu_find_by_mid(cpu, &cpu_node);
prom_startcpu(cpu_node, entry, cookie);
for (timeout = 0; timeout < 5000000; timeout++) {
if (callin_flag)
break;
udelay(100);
}
if (callin_flag) {
ret = 0;
} else {
printk("Processor %d is stuck.\n", cpu);
cpu_clear(cpu, cpu_callout_map);
ret = -ENODEV;
}
cpu_new_thread = NULL;
return ret;
}
static void spitfire_xcall_helper(u64 data0, u64 data1, u64 data2, u64 pstate, unsigned long cpu)
{
u64 result, target;
int stuck, tmp;
if (this_is_starfire) {
/* map to real upaid */
cpu = (((cpu & 0x3c) << 1) |
((cpu & 0x40) >> 4) |
(cpu & 0x3));
}
target = (cpu << 14) | 0x70;
again:
/* Ok, this is the real Spitfire Errata #54.
* One must read back from a UDB internal register
* after writes to the UDB interrupt dispatch, but
* before the membar Sync for that write.
* So we use the high UDB control register (ASI 0x7f,
* ADDR 0x20) for the dummy read. -DaveM
*/
tmp = 0x40;
__asm__ __volatile__(
"wrpr %1, %2, %%pstate\n\t"
"stxa %4, [%0] %3\n\t"
"stxa %5, [%0+%8] %3\n\t"
"add %0, %8, %0\n\t"
"stxa %6, [%0+%8] %3\n\t"
"membar #Sync\n\t"
"stxa %%g0, [%7] %3\n\t"
"membar #Sync\n\t"
"mov 0x20, %%g1\n\t"
"ldxa [%%g1] 0x7f, %%g0\n\t"
"membar #Sync"
: "=r" (tmp)
: "r" (pstate), "i" (PSTATE_IE), "i" (ASI_INTR_W),
"r" (data0), "r" (data1), "r" (data2), "r" (target),
"r" (0x10), "0" (tmp)
: "g1");
/* NOTE: PSTATE_IE is still clear. */
stuck = 100000;
do {
__asm__ __volatile__("ldxa [%%g0] %1, %0"
: "=r" (result)
: "i" (ASI_INTR_DISPATCH_STAT));
if (result == 0) {
__asm__ __volatile__("wrpr %0, 0x0, %%pstate"
: : "r" (pstate));
return;
}
stuck -= 1;
if (stuck == 0)
break;
} while (result & 0x1);
__asm__ __volatile__("wrpr %0, 0x0, %%pstate"
: : "r" (pstate));
if (stuck == 0) {
printk("CPU[%d]: mondo stuckage result[%016lx]\n",
smp_processor_id(), result);
} else {
udelay(2);
goto again;
}
}
static __inline__ void spitfire_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mask)
{
u64 pstate;
int i;
__asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
for_each_cpu_mask(i, mask)
spitfire_xcall_helper(data0, data1, data2, pstate, i);
}
/* Cheetah now allows to send the whole 64-bytes of data in the interrupt
* packet, but we have no use for that. However we do take advantage of
* the new pipelining feature (ie. dispatch to multiple cpus simultaneously).
*/
static void cheetah_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mask)
{
u64 pstate, ver;
int nack_busy_id, is_jalapeno;
if (cpus_empty(mask))
return;
/* Unfortunately, someone at Sun had the brilliant idea to make the
* busy/nack fields hard-coded by ITID number for this Ultra-III
* derivative processor.
*/
__asm__ ("rdpr %%ver, %0" : "=r" (ver));
is_jalapeno = ((ver >> 32) == 0x003e0016);
__asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
retry:
__asm__ __volatile__("wrpr %0, %1, %%pstate\n\t"
: : "r" (pstate), "i" (PSTATE_IE));
/* Setup the dispatch data registers. */
__asm__ __volatile__("stxa %0, [%3] %6\n\t"
"stxa %1, [%4] %6\n\t"
"stxa %2, [%5] %6\n\t"
"membar #Sync\n\t"
: /* no outputs */
: "r" (data0), "r" (data1), "r" (data2),
"r" (0x40), "r" (0x50), "r" (0x60),
"i" (ASI_INTR_W));
nack_busy_id = 0;
{
int i;
for_each_cpu_mask(i, mask) {
u64 target = (i << 14) | 0x70;
if (!is_jalapeno)
target |= (nack_busy_id << 24);
__asm__ __volatile__(
"stxa %%g0, [%0] %1\n\t"
"membar #Sync\n\t"
: /* no outputs */
: "r" (target), "i" (ASI_INTR_W));
nack_busy_id++;
}
}
/* Now, poll for completion. */
{
u64 dispatch_stat;
long stuck;
stuck = 100000 * nack_busy_id;
do {
__asm__ __volatile__("ldxa [%%g0] %1, %0"
: "=r" (dispatch_stat)
: "i" (ASI_INTR_DISPATCH_STAT));
if (dispatch_stat == 0UL) {
__asm__ __volatile__("wrpr %0, 0x0, %%pstate"
: : "r" (pstate));
return;
}
if (!--stuck)
break;
} while (dispatch_stat & 0x5555555555555555UL);
__asm__ __volatile__("wrpr %0, 0x0, %%pstate"
: : "r" (pstate));
if ((dispatch_stat & ~(0x5555555555555555UL)) == 0) {
/* Busy bits will not clear, continue instead
* of freezing up on this cpu.
*/
printk("CPU[%d]: mondo stuckage result[%016lx]\n",
smp_processor_id(), dispatch_stat);
} else {
int i, this_busy_nack = 0;
/* Delay some random time with interrupts enabled
* to prevent deadlock.
*/
udelay(2 * nack_busy_id);
/* Clear out the mask bits for cpus which did not
* NACK us.
*/
for_each_cpu_mask(i, mask) {
u64 check_mask;
if (is_jalapeno)
check_mask = (0x2UL << (2*i));
else
check_mask = (0x2UL <<
this_busy_nack);
if ((dispatch_stat & check_mask) == 0)
cpu_clear(i, mask);
this_busy_nack += 2;
}
goto retry;
}
}
}
/* Send cross call to all processors mentioned in MASK
* except self.
*/
static void smp_cross_call_masked(unsigned long *func, u32 ctx, u64 data1, u64 data2, cpumask_t mask)
{
u64 data0 = (((u64)ctx)<<32 | (((u64)func) & 0xffffffff));
int this_cpu = get_cpu();
cpus_and(mask, mask, cpu_online_map);
cpu_clear(this_cpu, mask);
if (tlb_type == spitfire)
spitfire_xcall_deliver(data0, data1, data2, mask);
else
cheetah_xcall_deliver(data0, data1, data2, mask);
/* NOTE: Caller runs local copy on master. */
put_cpu();
}
extern unsigned long xcall_sync_tick;
static void smp_start_sync_tick_client(int cpu)
{
cpumask_t mask = cpumask_of_cpu(cpu);
smp_cross_call_masked(&xcall_sync_tick,
0, 0, 0, mask);
}
/* Send cross call to all processors except self. */
#define smp_cross_call(func, ctx, data1, data2) \
smp_cross_call_masked(func, ctx, data1, data2, cpu_online_map)
struct call_data_struct {
void (*func) (void *info);
void *info;
atomic_t finished;
int wait;
};
static DEFINE_SPINLOCK(call_lock);
static struct call_data_struct *call_data;
extern unsigned long xcall_call_function;
/*
* You must not call this function with disabled interrupts or from a
* hardware interrupt handler or from a bottom half handler.
*/
int smp_call_function(void (*func)(void *info), void *info,
int nonatomic, int wait)
{
struct call_data_struct data;
int cpus = num_online_cpus() - 1;
long timeout;
if (!cpus)
return 0;
/* Can deadlock when called with interrupts disabled */
WARN_ON(irqs_disabled());
data.func = func;
data.info = info;
atomic_set(&data.finished, 0);
data.wait = wait;
spin_lock(&call_lock);
call_data = &data;
smp_cross_call(&xcall_call_function, 0, 0, 0);
/*
* Wait for other cpus to complete function or at
* least snap the call data.
*/
timeout = 1000000;
while (atomic_read(&data.finished) != cpus) {
if (--timeout <= 0)
goto out_timeout;
barrier();
udelay(1);
}
spin_unlock(&call_lock);
return 0;
out_timeout:
spin_unlock(&call_lock);
printk("XCALL: Remote cpus not responding, ncpus=%ld finished=%ld\n",
(long) num_online_cpus() - 1L,
(long) atomic_read(&data.finished));
return 0;
}
void smp_call_function_client(int irq, struct pt_regs *regs)
{
void (*func) (void *info) = call_data->func;
void *info = call_data->info;
clear_softint(1 << irq);
if (call_data->wait) {
/* let initiator proceed only after completion */
func(info);
atomic_inc(&call_data->finished);
} else {
/* let initiator proceed after getting data */
atomic_inc(&call_data->finished);
func(info);
}
}
extern unsigned long xcall_flush_tlb_mm;
extern unsigned long xcall_flush_tlb_pending;
extern unsigned long xcall_flush_tlb_kernel_range;
extern unsigned long xcall_flush_tlb_all_spitfire;
extern unsigned long xcall_flush_tlb_all_cheetah;
extern unsigned long xcall_report_regs;
extern unsigned long xcall_receive_signal;
#ifdef DCACHE_ALIASING_POSSIBLE
extern unsigned long xcall_flush_dcache_page_cheetah;
#endif
extern unsigned long xcall_flush_dcache_page_spitfire;
#ifdef CONFIG_DEBUG_DCFLUSH
extern atomic_t dcpage_flushes;
extern atomic_t dcpage_flushes_xcall;
#endif
static __inline__ void __local_flush_dcache_page(struct page *page)
{
#ifdef DCACHE_ALIASING_POSSIBLE
__flush_dcache_page(page_address(page),
((tlb_type == spitfire) &&
page_mapping(page) != NULL));
#else
if (page_mapping(page) != NULL &&
tlb_type == spitfire)
__flush_icache_page(__pa(page_address(page)));
#endif
}
void smp_flush_dcache_page_impl(struct page *page, int cpu)
{
cpumask_t mask = cpumask_of_cpu(cpu);
int this_cpu = get_cpu();
#ifdef CONFIG_DEBUG_DCFLUSH
atomic_inc(&dcpage_flushes);
#endif
if (cpu == this_cpu) {
__local_flush_dcache_page(page);
} else if (cpu_online(cpu)) {
void *pg_addr = page_address(page);
u64 data0;
if (tlb_type == spitfire) {
data0 =
((u64)&xcall_flush_dcache_page_spitfire);
if (page_mapping(page) != NULL)
data0 |= ((u64)1 << 32);
spitfire_xcall_deliver(data0,
__pa(pg_addr),
(u64) pg_addr,
mask);
} else {
#ifdef DCACHE_ALIASING_POSSIBLE
data0 =
((u64)&xcall_flush_dcache_page_cheetah);
cheetah_xcall_deliver(data0,
__pa(pg_addr),
0, mask);
#endif
}
#ifdef CONFIG_DEBUG_DCFLUSH
atomic_inc(&dcpage_flushes_xcall);
#endif
}
put_cpu();
}
void flush_dcache_page_all(struct mm_struct *mm, struct page *page)
{
void *pg_addr = page_address(page);
cpumask_t mask = cpu_online_map;
u64 data0;
int this_cpu = get_cpu();
cpu_clear(this_cpu, mask);
#ifdef CONFIG_DEBUG_DCFLUSH
atomic_inc(&dcpage_flushes);
#endif
if (cpus_empty(mask))
goto flush_self;
if (tlb_type == spitfire) {
data0 = ((u64)&xcall_flush_dcache_page_spitfire);
if (page_mapping(page) != NULL)
data0 |= ((u64)1 << 32);
spitfire_xcall_deliver(data0,
__pa(pg_addr),
(u64) pg_addr,
mask);
} else {
#ifdef DCACHE_ALIASING_POSSIBLE
data0 = ((u64)&xcall_flush_dcache_page_cheetah);
cheetah_xcall_deliver(data0,
__pa(pg_addr),
0, mask);
#endif
}
#ifdef CONFIG_DEBUG_DCFLUSH
atomic_inc(&dcpage_flushes_xcall);
#endif
flush_self:
__local_flush_dcache_page(page);
put_cpu();
}
void smp_receive_signal(int cpu)
{
cpumask_t mask = cpumask_of_cpu(cpu);
if (cpu_online(cpu)) {
u64 data0 = (((u64)&xcall_receive_signal) & 0xffffffff);
if (tlb_type == spitfire)
spitfire_xcall_deliver(data0, 0, 0, mask);
else
cheetah_xcall_deliver(data0, 0, 0, mask);
}
}
void smp_receive_signal_client(int irq, struct pt_regs *regs)
{
/* Just return, rtrap takes care of the rest. */
clear_softint(1 << irq);
}
void smp_report_regs(void)
{
smp_cross_call(&xcall_report_regs, 0, 0, 0);
}
void smp_flush_tlb_all(void)
{
if (tlb_type == spitfire)
smp_cross_call(&xcall_flush_tlb_all_spitfire, 0, 0, 0);
else
smp_cross_call(&xcall_flush_tlb_all_cheetah, 0, 0, 0);
__flush_tlb_all();
}
/* We know that the window frames of the user have been flushed
* to the stack before we get here because all callers of us
* are flush_tlb_*() routines, and these run after flush_cache_*()
* which performs the flushw.
*
* The SMP TLB coherency scheme we use works as follows:
*
* 1) mm->cpu_vm_mask is a bit mask of which cpus an address
* space has (potentially) executed on, this is the heuristic
* we use to avoid doing cross calls.
*
* Also, for flushing from kswapd and also for clones, we
* use cpu_vm_mask as the list of cpus to make run the TLB.
*
* 2) TLB context numbers are shared globally across all processors
* in the system, this allows us to play several games to avoid
* cross calls.
*
* One invariant is that when a cpu switches to a process, and
* that processes tsk->active_mm->cpu_vm_mask does not have the
* current cpu's bit set, that tlb context is flushed locally.
*
* If the address space is non-shared (ie. mm->count == 1) we avoid
* cross calls when we want to flush the currently running process's
* tlb state. This is done by clearing all cpu bits except the current
* processor's in current->active_mm->cpu_vm_mask and performing the
* flush locally only. This will force any subsequent cpus which run
* this task to flush the context from the local tlb if the process
* migrates to another cpu (again).
*
* 3) For shared address spaces (threads) and swapping we bite the
* bullet for most cases and perform the cross call (but only to
* the cpus listed in cpu_vm_mask).
*
* The performance gain from "optimizing" away the cross call for threads is
* questionable (in theory the big win for threads is the massive sharing of
* address space state across processors).
*/
void smp_flush_tlb_mm(struct mm_struct *mm)
{
/*
* This code is called from two places, dup_mmap and exit_mmap. In the
* former case, we really need a flush. In the later case, the callers
* are single threaded exec_mmap (really need a flush), multithreaded
* exec_mmap case (do not need to flush, since the caller gets a new
* context via activate_mm), and all other callers of mmput() whence
* the flush can be optimized since the associated threads are dead and
* the mm is being torn down (__exit_mm and other mmput callers) or the
* owning thread is dissociating itself from the mm. The
* (atomic_read(&mm->mm_users) == 0) check ensures real work is done
* for single thread exec and dup_mmap cases. An alternate check might
* have been (current->mm != mm).
* Kanoj Sarcar
*/
if (atomic_read(&mm->mm_users) == 0)
return;
{
u32 ctx = CTX_HWBITS(mm->context);
int cpu = get_cpu();
if (atomic_read(&mm->mm_users) == 1) {
mm->cpu_vm_mask = cpumask_of_cpu(cpu);
goto local_flush_and_out;
}
smp_cross_call_masked(&xcall_flush_tlb_mm,
ctx, 0, 0,
mm->cpu_vm_mask);
local_flush_and_out:
__flush_tlb_mm(ctx, SECONDARY_CONTEXT);
put_cpu();
}
}
void smp_flush_tlb_pending(struct mm_struct *mm, unsigned long nr, unsigned long *vaddrs)
{
u32 ctx = CTX_HWBITS(mm->context);
int cpu = get_cpu();
if (mm == current->active_mm && atomic_read(&mm->mm_users) == 1) {
mm->cpu_vm_mask = cpumask_of_cpu(cpu);
goto local_flush_and_out;
} else {
/* This optimization is not valid. Normally
* we will be holding the page_table_lock, but
* there is an exception which is copy_page_range()
* when forking. The lock is held during the individual
* page table updates in the parent, but not at the
* top level, which is where we are invoked.
*/
if (0) {
cpumask_t this_cpu_mask = cpumask_of_cpu(cpu);
/* By virtue of running under the mm->page_table_lock,
* and mmu_context.h:switch_mm doing the same, the
* following operation is safe.
*/
if (cpus_equal(mm->cpu_vm_mask, this_cpu_mask))
goto local_flush_and_out;
}
}
smp_cross_call_masked(&xcall_flush_tlb_pending,
ctx, nr, (unsigned long) vaddrs,
mm->cpu_vm_mask);
local_flush_and_out:
__flush_tlb_pending(ctx, nr, vaddrs);
put_cpu();
}
void smp_flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
start &= PAGE_MASK;
end = PAGE_ALIGN(end);
if (start != end) {
smp_cross_call(&xcall_flush_tlb_kernel_range,
0, start, end);
__flush_tlb_kernel_range(start, end);
}
}
/* CPU capture. */
/* #define CAPTURE_DEBUG */
extern unsigned long xcall_capture;
static atomic_t smp_capture_depth = ATOMIC_INIT(0);
static atomic_t smp_capture_registry = ATOMIC_INIT(0);
static unsigned long penguins_are_doing_time;
void smp_capture(void)
{
int result = atomic_add_ret(1, &smp_capture_depth);
if (result == 1) {
int ncpus = num_online_cpus();
#ifdef CAPTURE_DEBUG
printk("CPU[%d]: Sending penguins to jail...",
smp_processor_id());
#endif
penguins_are_doing_time = 1;
membar_storestore_loadstore();
atomic_inc(&smp_capture_registry);
smp_cross_call(&xcall_capture, 0, 0, 0);
while (atomic_read(&smp_capture_registry) != ncpus)
rmb();
#ifdef CAPTURE_DEBUG
printk("done\n");
#endif
}
}
void smp_release(void)
{
if (atomic_dec_and_test(&smp_capture_depth)) {
#ifdef CAPTURE_DEBUG
printk("CPU[%d]: Giving pardon to "
"imprisoned penguins\n",
smp_processor_id());
#endif
penguins_are_doing_time = 0;
membar_storeload_storestore();
atomic_dec(&smp_capture_registry);
}
}
/* Imprisoned penguins run with %pil == 15, but PSTATE_IE set, so they
* can service tlb flush xcalls...
*/
extern void prom_world(int);
extern void save_alternate_globals(unsigned long *);
extern void restore_alternate_globals(unsigned long *);
void smp_penguin_jailcell(int irq, struct pt_regs *regs)
{
unsigned long global_save[24];
clear_softint(1 << irq);
preempt_disable();
__asm__ __volatile__("flushw");
save_alternate_globals(global_save);
prom_world(1);
atomic_inc(&smp_capture_registry);
membar_storeload_storestore();
while (penguins_are_doing_time)
rmb();
restore_alternate_globals(global_save);
atomic_dec(&smp_capture_registry);
prom_world(0);
preempt_enable();
}
extern unsigned long xcall_promstop;
void smp_promstop_others(void)
{
smp_cross_call(&xcall_promstop, 0, 0, 0);
}
#define prof_multiplier(__cpu) cpu_data(__cpu).multiplier
#define prof_counter(__cpu) cpu_data(__cpu).counter
void smp_percpu_timer_interrupt(struct pt_regs *regs)
{
unsigned long compare, tick, pstate;
int cpu = smp_processor_id();
int user = user_mode(regs);
/*
* Check for level 14 softint.
*/
{
unsigned long tick_mask = tick_ops->softint_mask;
if (!(get_softint() & tick_mask)) {
extern void handler_irq(int, struct pt_regs *);
handler_irq(14, regs);
return;
}
clear_softint(tick_mask);
}
do {
profile_tick(CPU_PROFILING, regs);
if (!--prof_counter(cpu)) {
irq_enter();
if (cpu == boot_cpu_id) {
kstat_this_cpu.irqs[0]++;
timer_tick_interrupt(regs);
}
update_process_times(user);
irq_exit();
prof_counter(cpu) = prof_multiplier(cpu);
}
/* Guarantee that the following sequences execute
* uninterrupted.
*/
__asm__ __volatile__("rdpr %%pstate, %0\n\t"
"wrpr %0, %1, %%pstate"
: "=r" (pstate)
: "i" (PSTATE_IE));
compare = tick_ops->add_compare(current_tick_offset);
tick = tick_ops->get_tick();
/* Restore PSTATE_IE. */
__asm__ __volatile__("wrpr %0, 0x0, %%pstate"
: /* no outputs */
: "r" (pstate));
} while (time_after_eq(tick, compare));
}
static void __init smp_setup_percpu_timer(void)
{
int cpu = smp_processor_id();
unsigned long pstate;
prof_counter(cpu) = prof_multiplier(cpu) = 1;
/* Guarantee that the following sequences execute
* uninterrupted.
*/
__asm__ __volatile__("rdpr %%pstate, %0\n\t"
"wrpr %0, %1, %%pstate"
: "=r" (pstate)
: "i" (PSTATE_IE));
tick_ops->init_tick(current_tick_offset);
/* Restore PSTATE_IE. */
__asm__ __volatile__("wrpr %0, 0x0, %%pstate"
: /* no outputs */
: "r" (pstate));
}
void __init smp_tick_init(void)
{
boot_cpu_id = hard_smp_processor_id();
current_tick_offset = timer_tick_offset;
cpu_set(boot_cpu_id, cpu_online_map);
prof_counter(boot_cpu_id) = prof_multiplier(boot_cpu_id) = 1;
}
/* /proc/profile writes can call this, don't __init it please. */
static DEFINE_SPINLOCK(prof_setup_lock);
int setup_profiling_timer(unsigned int multiplier)
{
unsigned long flags;
int i;
if ((!multiplier) || (timer_tick_offset / multiplier) < 1000)
return -EINVAL;
spin_lock_irqsave(&prof_setup_lock, flags);
for (i = 0; i < NR_CPUS; i++)
prof_multiplier(i) = multiplier;
current_tick_offset = (timer_tick_offset / multiplier);
spin_unlock_irqrestore(&prof_setup_lock, flags);
return 0;
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
int instance, mid;
instance = 0;
while (!cpu_find_by_instance(instance, NULL, &mid)) {
if (mid < max_cpus)
cpu_set(mid, phys_cpu_present_map);
instance++;
}
if (num_possible_cpus() > max_cpus) {
instance = 0;
while (!cpu_find_by_instance(instance, NULL, &mid)) {
if (mid != boot_cpu_id) {
cpu_clear(mid, phys_cpu_present_map);
if (num_possible_cpus() <= max_cpus)
break;
}
instance++;
}
}
smp_store_cpu_info(boot_cpu_id);
}
void __devinit smp_prepare_boot_cpu(void)
{
if (hard_smp_processor_id() >= NR_CPUS) {
prom_printf("Serious problem, boot cpu id >= NR_CPUS\n");
prom_halt();
}
current_thread_info()->cpu = hard_smp_processor_id();
cpu_set(smp_processor_id(), cpu_online_map);
cpu_set(smp_processor_id(), phys_cpu_present_map);
}
int __devinit __cpu_up(unsigned int cpu)
{
int ret = smp_boot_one_cpu(cpu);
if (!ret) {
cpu_set(cpu, smp_commenced_mask);
while (!cpu_isset(cpu, cpu_online_map))
mb();
if (!cpu_isset(cpu, cpu_online_map)) {
ret = -ENODEV;
} else {
smp_synchronize_one_tick(cpu);
}
}
return ret;
}
void __init smp_cpus_done(unsigned int max_cpus)
{
unsigned long bogosum = 0;
int i;
for (i = 0; i < NR_CPUS; i++) {
if (cpu_online(i))
bogosum += cpu_data(i).udelay_val;
}
printk("Total of %ld processors activated "
"(%lu.%02lu BogoMIPS).\n",
(long) num_online_cpus(),
bogosum/(500000/HZ),
(bogosum/(5000/HZ))%100);
}
/* This needn't do anything as we do not sleep the cpu
* inside of the idler task, so an interrupt is not needed
* to get a clean fast response.
*
* XXX Reverify this assumption... -DaveM
*
* Addendum: We do want it to do something for the signal
* delivery case, we detect that by just seeing
* if we are trying to send this to an idler or not.
*/
void smp_send_reschedule(int cpu)
{
if (cpu_data(cpu).idle_volume == 0)
smp_receive_signal(cpu);
}
/* This is a nop because we capture all other cpus
* anyways when making the PROM active.
*/
void smp_send_stop(void)
{
}
unsigned long __per_cpu_base __read_mostly;
unsigned long __per_cpu_shift __read_mostly;
EXPORT_SYMBOL(__per_cpu_base);
EXPORT_SYMBOL(__per_cpu_shift);
void __init setup_per_cpu_areas(void)
{
unsigned long goal, size, i;
char *ptr;
/* Created by linker magic */
extern char __per_cpu_start[], __per_cpu_end[];
/* Copy section for each CPU (we discard the original) */
goal = ALIGN(__per_cpu_end - __per_cpu_start, PAGE_SIZE);
#ifdef CONFIG_MODULES
if (goal < PERCPU_ENOUGH_ROOM)
goal = PERCPU_ENOUGH_ROOM;
#endif
__per_cpu_shift = 0;
for (size = 1UL; size < goal; size <<= 1UL)
__per_cpu_shift++;
/* Make sure the resulting __per_cpu_base value
* will fit in the 43-bit sign extended IMMU
* TSB register.
*/
ptr = __alloc_bootmem(size * NR_CPUS, PAGE_SIZE,
(unsigned long) __per_cpu_start);
__per_cpu_base = ptr - __per_cpu_start;
if ((__per_cpu_shift < PAGE_SHIFT) ||
(__per_cpu_base & ~PAGE_MASK) ||
(__per_cpu_base != (((long) __per_cpu_base << 20) >> 20))) {
prom_printf("PER_CPU: Invalid layout, "
"ptr[%p] shift[%lx] base[%lx]\n",
ptr, __per_cpu_shift, __per_cpu_base);
prom_halt();
}
for (i = 0; i < NR_CPUS; i++, ptr += size)
memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
/* Finally, load in the boot cpu's base value.
* We abuse the IMMU TSB register for trap handler
* entry and exit loading of %g5. That is why it
* has to be page aligned.
*/
cpu_setup_percpu_base(hard_smp_processor_id());
}
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