-/* Copyright (C) 2004 Mips Technologies, Inc */
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) 2004 Mips Technologies, Inc
+ * Copyright (C) 2008 Kevin D. Kissell
+ */
#include <linux/clockchips.h>
#include <linux/kernel.h>
#include <linux/sched.h>
+#include <linux/smp.h>
#include <linux/cpumask.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <asm/time.h>
#include <asm/addrspace.h>
#include <asm/smtc.h>
-#include <asm/smtc_ipi.h>
#include <asm/smtc_proc.h>
/*
asiduse smtc_live_asid[MAX_SMTC_TLBS][MAX_SMTC_ASIDS];
/*
- * Clock interrupt "latch" buffers, per "CPU"
- */
-
-static atomic_t ipi_timer_latch[NR_CPUS];
-
-/*
* Number of InterProcessor Interrupt (IPI) message buffers to allocate
*/
#define IPIBUF_PER_CPU 4
-static struct smtc_ipi_q IPIQ[NR_CPUS];
+struct smtc_ipi_q IPIQ[NR_CPUS];
static struct smtc_ipi_q freeIPIq;
/* Global SMTC Status */
-unsigned int smtc_status = 0;
+unsigned int smtc_status;
/* Boot command line configuration overrides */
static int vpe0limit;
-static int ipibuffers = 0;
-static int nostlb = 0;
-static int asidmask = 0;
+static int ipibuffers;
+static int nostlb;
+static int asidmask;
unsigned long smtc_asid_mask = 0xff;
static int __init vpe0tcs(char *str)
#ifdef CONFIG_SMTC_IDLE_HOOK_DEBUG
-static int hang_trig = 0;
+static int hang_trig;
static int __init hangtrig_enable(char *s)
{
* possibly leave some TCs/VPEs as "slave" processors.
*
* Use c0_MVPConf0 to find out how many TCs are available, setting up
- * phys_cpu_present_map and the logical/physical mappings.
+ * cpu_possible_map and the logical/physical mappings.
*/
-int __init mipsmt_build_cpu_map(int start_cpu_slot)
+int __init smtc_build_cpu_map(int start_cpu_slot)
{
int i, ntcs;
*/
ntcs = ((read_c0_mvpconf0() & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1;
for (i=start_cpu_slot; i<NR_CPUS && i<ntcs; i++) {
- cpu_set(i, phys_cpu_present_map);
+ set_cpu_possible(i, true);
__cpu_number_map[i] = i;
__cpu_logical_map[i] = i;
}
write_tc_c0_tcstatus((read_tc_c0_tcstatus()
& ~(TCSTATUS_TKSU | TCSTATUS_DA | TCSTATUS_IXMT))
| TCSTATUS_A);
- write_tc_c0_tccontext(0);
+ /*
+ * TCContext gets an offset from the base of the IPIQ array
+ * to be used in low-level code to detect the presence of
+ * an active IPI queue
+ */
+ write_tc_c0_tccontext((sizeof(struct smtc_ipi_q) * cpu) << 16);
/* Bind tc to vpe */
write_tc_c0_tcbind(vpe);
/* In general, all TCs should have the same cpu_data indications */
memcpy(&cpu_data[cpu], &cpu_data[0], sizeof(struct cpuinfo_mips));
/* For 34Kf, start with TC/CPU 0 as sole owner of single FPU context */
- if (cpu_data[0].cputype == CPU_34K)
+ if (cpu_data[0].cputype == CPU_34K ||
+ cpu_data[0].cputype == CPU_1004K)
cpu_data[cpu].options &= ~MIPS_CPU_FPU;
cpu_data[cpu].vpe_id = vpe;
cpu_data[cpu].tc_id = tc;
+ /* Multi-core SMTC hasn't been tested, but be prepared */
+ cpu_data[cpu].core = (read_vpe_c0_ebase() >> 1) & 0xff;
}
+/*
+ * Tweak to get Count registes in as close a sync as possible.
+ * Value seems good for 34K-class cores.
+ */
+
+#define CP0_SKEW 8
-void mipsmt_prepare_cpus(void)
+void smtc_prepare_cpus(int cpus)
{
int i, vpe, tc, ntc, nvpe, tcpervpe[NR_CPUS], slop, cpu;
unsigned long flags;
IPIQ[i].head = IPIQ[i].tail = NULL;
spin_lock_init(&IPIQ[i].lock);
IPIQ[i].depth = 0;
- atomic_set(&ipi_timer_latch[i], 0);
+ IPIQ[i].resched_flag = 0; /* No reschedules queued initially */
}
/* cpu_data index starts at zero */
cpu = 0;
cpu_data[cpu].vpe_id = 0;
cpu_data[cpu].tc_id = 0;
+ cpu_data[cpu].core = (read_c0_ebase() >> 1) & 0xff;
cpu++;
/* Report on boot-time options */
smtc_configure_tlb();
for (tc = 0, vpe = 0 ; (vpe < nvpe) && (tc < ntc) ; vpe++) {
- /*
- * Set the MVP bits.
- */
- settc(tc);
- write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_MVP);
+ if (tcpervpe[vpe] == 0)
+ continue;
if (vpe != 0)
printk(", ");
printk("VPE %d: TC", vpe);
}
if (vpe != 0) {
/*
+ * Allow this VPE to control others.
+ */
+ write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() |
+ VPECONF0_MVP);
+
+ /*
* Clear any stale software interrupts from VPE's Cause
*/
write_vpe_c0_cause(0);
write_vpe_c0_compare(0);
/* Propagate Config7 */
write_vpe_c0_config7(read_c0_config7());
- write_vpe_c0_count(read_c0_count());
+ write_vpe_c0_count(read_c0_count() + CP0_SKEW);
+ ehb();
}
/* enable multi-threading within VPE */
write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() | VPECONTROL_TE);
* Pull any physically present but unused TCs out of circulation.
*/
while (tc < (((val & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1)) {
- cpu_clear(tc, phys_cpu_present_map);
- cpu_clear(tc, cpu_present_map);
+ set_cpu_possible(tc, false);
+ set_cpu_present(tc, false);
tc++;
}
void __cpuinit smtc_boot_secondary(int cpu, struct task_struct *idle)
{
extern u32 kernelsp[NR_CPUS];
- long flags;
+ unsigned long flags;
int mtflags;
LOCK_MT_PRA();
void smtc_init_secondary(void)
{
- /*
- * Start timer on secondary VPEs if necessary.
- * plat_timer_setup has already have been invoked by init/main
- * on "boot" TC. Like per_cpu_trap_init() hack, this assumes that
- * SMTC init code assigns TCs consdecutively and in ascending order
- * to across available VPEs.
- */
- if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
- ((read_c0_tcbind() & TCBIND_CURVPE)
- != cpu_data[smp_processor_id() - 1].vpe_id)){
- write_c0_compare(read_c0_count() + mips_hpt_frequency/HZ);
- }
-
local_irq_enable();
}
void smtc_smp_finish(void)
{
+ int cpu = smp_processor_id();
+
+ /*
+ * Lowest-numbered CPU per VPE starts a clock tick.
+ * Like per_cpu_trap_init() hack, this assumes that
+ * SMTC init code assigns TCs consdecutively and
+ * in ascending order across available VPEs.
+ */
+ if (cpu > 0 && (cpu_data[cpu].vpe_id != cpu_data[cpu - 1].vpe_id))
+ write_c0_compare(read_c0_count() + mips_hpt_frequency/HZ);
+
printk("TC %d going on-line as CPU %d\n",
cpu_data[smp_processor_id()].tc_id, smp_processor_id());
}
* and efficiency, we just pick the easiest one to find.
*/
- target = first_cpu(irq_desc[irq].affinity);
+ target = cpumask_first(irq_desc[irq].affinity);
/*
* We depend on the platform code to have correctly processed
static void smtc_ipi_qdump(void)
{
int i;
+ struct smtc_ipi *temp;
for (i = 0; i < NR_CPUS ;i++) {
- printk("IPIQ[%d]: head = 0x%x, tail = 0x%x, depth = %d\n",
+ pr_info("IPIQ[%d]: head = 0x%x, tail = 0x%x, depth = %d\n",
i, (unsigned)IPIQ[i].head, (unsigned)IPIQ[i].tail,
IPIQ[i].depth);
+ temp = IPIQ[i].head;
+
+ while (temp != IPIQ[i].tail) {
+ pr_debug("%d %d %d: ", temp->type, temp->dest,
+ (int)temp->arg);
+#ifdef SMTC_IPI_DEBUG
+ pr_debug("%u %lu\n", temp->sender, temp->stamp);
+#else
+ pr_debug("\n");
+#endif
+ temp = temp->flink;
+ }
}
}
{
int tcstatus;
struct smtc_ipi *pipi;
- long flags;
+ unsigned long flags;
int mtflags;
+ unsigned long tcrestart;
+ extern void r4k_wait_irqoff(void), __pastwait(void);
+ int set_resched_flag = (type == LINUX_SMP_IPI &&
+ action == SMP_RESCHEDULE_YOURSELF);
if (cpu == smp_processor_id()) {
printk("Cannot Send IPI to self!\n");
return;
}
+ if (set_resched_flag && IPIQ[cpu].resched_flag != 0)
+ return; /* There is a reschedule queued already */
+
/* Set up a descriptor, to be delivered either promptly or queued */
pipi = smtc_ipi_dq(&freeIPIq);
if (pipi == NULL) {
pipi->arg = (void *)action;
pipi->dest = cpu;
if (cpu_data[cpu].vpe_id != cpu_data[smp_processor_id()].vpe_id) {
- if (type == SMTC_CLOCK_TICK)
- atomic_inc(&ipi_timer_latch[cpu]);
/* If not on same VPE, enqueue and send cross-VPE interrupt */
+ IPIQ[cpu].resched_flag |= set_resched_flag;
smtc_ipi_nq(&IPIQ[cpu], pipi);
LOCK_CORE_PRA();
settc(cpu_data[cpu].tc_id);
if ((tcstatus & TCSTATUS_IXMT) != 0) {
/*
- * Spin-waiting here can deadlock,
- * so we queue the message for the target TC.
+ * If we're in the the irq-off version of the wait
+ * loop, we need to force exit from the wait and
+ * do a direct post of the IPI.
+ */
+ if (cpu_wait == r4k_wait_irqoff) {
+ tcrestart = read_tc_c0_tcrestart();
+ if (tcrestart >= (unsigned long)r4k_wait_irqoff
+ && tcrestart < (unsigned long)__pastwait) {
+ write_tc_c0_tcrestart(__pastwait);
+ tcstatus &= ~TCSTATUS_IXMT;
+ write_tc_c0_tcstatus(tcstatus);
+ goto postdirect;
+ }
+ }
+ /*
+ * Otherwise we queue the message for the target TC
+ * to pick up when he does a local_irq_restore()
*/
write_tc_c0_tchalt(0);
UNLOCK_CORE_PRA();
- /* Try to reduce redundant timer interrupt messages */
- if (type == SMTC_CLOCK_TICK) {
- if (atomic_postincrement(&ipi_timer_latch[cpu])!=0){
- smtc_ipi_nq(&freeIPIq, pipi);
- return;
- }
- }
+ IPIQ[cpu].resched_flag |= set_resched_flag;
smtc_ipi_nq(&IPIQ[cpu], pipi);
} else {
- if (type == SMTC_CLOCK_TICK)
- atomic_inc(&ipi_timer_latch[cpu]);
+postdirect:
post_direct_ipi(cpu, pipi);
write_tc_c0_tchalt(0);
UNLOCK_CORE_PRA();
/* Return from interrupt should be enough to cause scheduler check */
}
-
static void ipi_call_interrupt(void)
{
/* Invoke generic function invocation code in smp.c */
smp_call_function_interrupt();
}
-DECLARE_PER_CPU(struct clock_event_device, smtc_dummy_clockevent_device);
+DECLARE_PER_CPU(struct clock_event_device, mips_clockevent_device);
void ipi_decode(struct smtc_ipi *pipi)
{
struct clock_event_device *cd;
void *arg_copy = pipi->arg;
int type_copy = pipi->type;
- int ticks;
+ int irq = MIPS_CPU_IRQ_BASE + 1;
smtc_ipi_nq(&freeIPIq, pipi);
+
switch (type_copy) {
case SMTC_CLOCK_TICK:
irq_enter();
- kstat_this_cpu.irqs[MIPS_CPU_IRQ_BASE + 1]++;
- cd = &per_cpu(smtc_dummy_clockevent_device, cpu);
- ticks = atomic_read(&ipi_timer_latch[cpu]);
- atomic_sub(ticks, &ipi_timer_latch[cpu]);
- while (ticks) {
- cd->event_handler(cd);
- ticks--;
- }
+ kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
+ cd = &per_cpu(mips_clockevent_device, cpu);
+ cd->event_handler(cd);
irq_exit();
break;
}
}
+/*
+ * Similar to smtc_ipi_replay(), but invoked from context restore,
+ * so it reuses the current exception frame rather than set up a
+ * new one with self_ipi.
+ */
+
void deferred_smtc_ipi(void)
{
- struct smtc_ipi *pipi;
- unsigned long flags;
-/* DEBUG */
- int q = smp_processor_id();
+ int cpu = smp_processor_id();
/*
* Test is not atomic, but much faster than a dequeue,
* and the vast majority of invocations will have a null queue.
+ * If irq_disabled when this was called, then any IPIs queued
+ * after we test last will be taken on the next irq_enable/restore.
+ * If interrupts were enabled, then any IPIs added after the
+ * last test will be taken directly.
*/
- if (IPIQ[q].head != NULL) {
- while((pipi = smtc_ipi_dq(&IPIQ[q])) != NULL) {
- /* ipi_decode() should be called with interrupts off */
- local_irq_save(flags);
+
+ while (IPIQ[cpu].head != NULL) {
+ struct smtc_ipi_q *q = &IPIQ[cpu];
+ struct smtc_ipi *pipi;
+ unsigned long flags;
+
+ /*
+ * It may be possible we'll come in with interrupts
+ * already enabled.
+ */
+ local_irq_save(flags);
+ spin_lock(&q->lock);
+ pipi = __smtc_ipi_dq(q);
+ spin_unlock(&q->lock);
+ if (pipi != NULL) {
+ if (pipi->type == LINUX_SMP_IPI &&
+ (int)pipi->arg == SMP_RESCHEDULE_YOURSELF)
+ IPIQ[cpu].resched_flag = 0;
ipi_decode(pipi);
- local_irq_restore(flags);
}
+ /*
+ * The use of the __raw_local restore isn't
+ * as obviously necessary here as in smtc_ipi_replay(),
+ * but it's more efficient, given that we're already
+ * running down the IPI queue.
+ */
+ __raw_local_irq_restore(flags);
}
}
struct smtc_ipi *pipi;
unsigned long tcstatus;
int sent;
- long flags;
+ unsigned long flags;
unsigned int mtflags;
unsigned int vpflags;
* with interrupts off
*/
local_irq_save(flags);
+ if (pipi->type == LINUX_SMP_IPI &&
+ (int)pipi->arg == SMP_RESCHEDULE_YOURSELF)
+ IPIQ[cpu].resched_flag = 0;
ipi_decode(pipi);
local_irq_restore(flags);
}
static struct irqaction irq_ipi = {
.handler = ipi_interrupt,
- .flags = IRQF_DISABLED,
- .name = "SMTC_IPI",
- .flags = IRQF_PERCPU
+ .flags = IRQF_DISABLED | IRQF_PERCPU,
+ .name = "SMTC_IPI"
};
static void setup_cross_vpe_interrupts(unsigned int nvpe)
/*
* SMTC-specific hacks invoked from elsewhere in the kernel.
- *
- * smtc_ipi_replay is called from raw_local_irq_restore which is only ever
- * called with interrupts disabled. We do rely on interrupts being disabled
- * here because using spin_lock_irqsave()/spin_unlock_irqrestore() would
- * result in a recursive call to raw_local_irq_restore().
*/
-static void __smtc_ipi_replay(void)
+ /*
+ * smtc_ipi_replay is called from raw_local_irq_restore
+ */
+
+void smtc_ipi_replay(void)
{
unsigned int cpu = smp_processor_id();
/*
* To the extent that we've ever turned interrupts off,
* we may have accumulated deferred IPIs. This is subtle.
- * If we use the smtc_ipi_qdepth() macro, we'll get an
- * exact number - but we'll also disable interrupts
- * and create a window of failure where a new IPI gets
- * queued after we test the depth but before we re-enable
- * interrupts. So long as IXMT never gets set, however,
* we should be OK: If we pick up something and dispatch
* it here, that's great. If we see nothing, but concurrent
* with this operation, another TC sends us an IPI, IXMT
* is clear, and we'll handle it as a real pseudo-interrupt
- * and not a pseudo-pseudo interrupt.
+ * and not a pseudo-pseudo interrupt. The important thing
+ * is to do the last check for queued message *after* the
+ * re-enabling of interrupts.
*/
- if (IPIQ[cpu].depth > 0) {
- while (1) {
- struct smtc_ipi_q *q = &IPIQ[cpu];
- struct smtc_ipi *pipi;
- extern void self_ipi(struct smtc_ipi *);
-
- spin_lock(&q->lock);
- pipi = __smtc_ipi_dq(q);
- spin_unlock(&q->lock);
- if (!pipi)
- break;
+ while (IPIQ[cpu].head != NULL) {
+ struct smtc_ipi_q *q = &IPIQ[cpu];
+ struct smtc_ipi *pipi;
+ unsigned long flags;
+ /*
+ * It's just possible we'll come in with interrupts
+ * already enabled.
+ */
+ local_irq_save(flags);
+
+ spin_lock(&q->lock);
+ pipi = __smtc_ipi_dq(q);
+ spin_unlock(&q->lock);
+ /*
+ ** But use a raw restore here to avoid recursion.
+ */
+ __raw_local_irq_restore(flags);
+
+ if (pipi) {
self_ipi(pipi);
smtc_cpu_stats[cpu].selfipis++;
}
}
}
-void smtc_ipi_replay(void)
-{
- raw_local_irq_disable();
- __smtc_ipi_replay();
-}
-
EXPORT_SYMBOL(smtc_ipi_replay);
void smtc_idle_loop_hook(void)
}
}
- /*
- * Now that we limit outstanding timer IPIs, check for hung TC
- */
- for (tc = 0; tc < NR_CPUS; tc++) {
- /* Don't check ourself - we'll dequeue IPIs just below */
- if ((tc != smp_processor_id()) &&
- atomic_read(&ipi_timer_latch[tc]) > timerq_limit) {
- if (clock_hang_reported[tc] == 0) {
- pdb_msg += sprintf(pdb_msg,
- "TC %d looks hung with timer latch at %d\n",
- tc, atomic_read(&ipi_timer_latch[tc]));
- clock_hang_reported[tc]++;
- }
- }
- }
emt(mtflags);
local_irq_restore(flags);
if (pdb_msg != &id_ho_db_msg[0])
printk("CPU%d: %s", smp_processor_id(), id_ho_db_msg);
#endif /* CONFIG_SMTC_IDLE_HOOK_DEBUG */
- /*
- * Replay any accumulated deferred IPIs. If "Instant Replay"
- * is in use, there should never be any.
- */
-#ifndef CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY
- {
- unsigned long flags;
-
- local_irq_save(flags);
- __smtc_ipi_replay();
- local_irq_restore(flags);
- }
-#endif /* CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY */
+ smtc_ipi_replay();
}
void smtc_soft_dump(void)
printk("%d: %ld\n", i, smtc_cpu_stats[i].selfipis);
}
smtc_ipi_qdump();
- printk("Timer IPI Backlogs:\n");
- for (i=0; i < NR_CPUS; i++) {
- printk("%d: %d\n", i, atomic_read(&ipi_timer_latch[i]));
- }
printk("%d Recoveries of \"stolen\" FPU\n",
atomic_read(&smtc_fpu_recoveries));
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff