Commit 576a9e87 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds

[PATCH] ppc64 cpu spinup fixes

From: Rusty Russell <rusty@rustcorp.com.au>

1) Check for cpuids >= NR_CPUS in prom_hold_cpus: we previously
   overflowed arrays when this happened, and checking it here ensures
   that it doesn't happen elsewhere.  Still move processors to
   secondary_hold (out of OF), but we won't release them.

2) smp_iSeries_message_pass and smp_xics_message_pass don't need to
   iterate if given a specific CPU: cleanup and fix.

3) kick_cpu variants don't need to check cpu range (caller is screwed
   anyway if this happened): replaced with BUG_ON for now.

4) smp_openpic_probe and smp_xics_probe can use cpus_weight(): it's
   faster and simpler.

5) User for_each_cpu/for_each_online_cpu as appropriate.
parent fbd7abeb
......@@ -30,6 +30,7 @@
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/stringify.h>
#include <linux/delay.h>
#include <asm/prom.h>
#include <asm/rtas.h>
......@@ -1073,6 +1074,10 @@ prom_hold_cpus(unsigned long mem)
if (*acknowledge == cpuid) {
prom_print(RELOC("ok\n"));
/* We have to get every CPU out of OF,
* even if we never start it. */
if (cpuid >= NR_CPUS)
goto next;
#ifdef CONFIG_SMP
/* Set the number of active processors. */
_systemcfg->processorCount++;
......@@ -1099,9 +1104,12 @@ prom_hold_cpus(unsigned long mem)
cpu_set(cpuid, RELOC(cpu_present_at_boot));
}
next:
/* Init paca for secondary threads. They start later. */
for (i=1; i < cpu_threads; i++) {
cpuid++;
if (cpuid >= NR_CPUS)
continue;
_xPaca[cpuid].xHwProcNum = interrupt_server[i];
prom_print_hex(interrupt_server[i]);
prom_print(RELOC(" : preparing thread ... "));
......@@ -1146,7 +1154,11 @@ prom_hold_cpus(unsigned long mem)
prom_print(RELOC("Processor is not HMT capable\n"));
}
#endif
if (cpuid >= NR_CPUS)
prom_print(RELOC("WARNING: maximum CPUs (" __stringify(NR_CPUS)
") exceeded: ignoring extras\n"));
#ifdef DEBUG_PROM
prom_print(RELOC("prom_hold_cpus: end...\n"));
#endif
......
......@@ -95,20 +95,25 @@ void iSeries_smp_message_recv( struct pt_regs * regs )
smp_message_recv( msg, regs );
}
static void smp_iSeries_message_pass(int target, int msg, unsigned long data, int wait)
static inline void smp_iSeries_do_message(int cpu, int msg)
{
int i;
set_bit(msg, &iSeries_smp_message[cpu]);
HvCall_sendIPI(&(paca[cpu]));
}
for (i = 0; i < NR_CPUS; ++i) {
if (!cpu_online(i))
continue;
static void
smp_iSeries_message_pass(int target, int msg, long data, int wait)
{
int i;
if ((target == MSG_ALL) ||
(target == i) ||
((target == MSG_ALL_BUT_SELF) &&
(i != smp_processor_id())) ) {
set_bit(msg, &iSeries_smp_message[i]);
HvCall_sendIPI(&(paca[i]));
if (target < NR_CPUS)
smp_iSeries_do_message(target, msg);
else {
for_each_online_cpu(i) {
if (target == MSG_ALL_BUT_SELF
&& i == smp_processor_id())
continue;
smp_iSeries_do_message(i, msg);
}
}
}
......@@ -151,21 +156,14 @@ static int smp_iSeries_probe(void)
static void smp_iSeries_kick_cpu(int nr)
{
struct ItLpPaca * lpPaca;
/* Verify we have a Paca for processor nr */
if ( ( nr <= 0 ) ||
( nr >= NR_CPUS ) )
return;
BUG_ON(nr < 0 || nr >= NR_CPUS);
/* Verify that our partition has a processor nr */
lpPaca = paca[nr].xLpPacaPtr;
if ( lpPaca->xDynProcStatus >= 2 )
if (lpPaca->xDynProcStatus >= 2)
return;
/* The information for processor bringup must
* be written out to main store before we release
* the processor.
*/
mb();
/* The processor is currently spinning, waiting
* for the xProcStart field to become non-zero
* After we set xProcStart, the processor will
......@@ -219,13 +217,9 @@ void smp_openpic_message_pass(int target, int msg, unsigned long data, int wait)
static int __init smp_openpic_probe(void)
{
int i;
int nr_cpus = 0;
int nr_cpus;
for (i = 0; i < NR_CPUS; i++) {
if (cpu_possible(i))
nr_cpus++;
}
nr_cpus = cpus_weight(cpu_possible_map);
if (nr_cpus > 1)
openpic_request_IPIs();
......@@ -240,16 +234,7 @@ static void __devinit smp_openpic_setup_cpu(int cpu)
static void smp_pSeries_kick_cpu(int nr)
{
/* Verify we have a Paca for processor nr */
if ( ( nr <= 0 ) ||
( nr >= NR_CPUS ) )
return;
/* The information for processor bringup must
* be written out to main store before we release
* the processor.
*/
mb();
BUG_ON(nr < 0 || nr >= NR_CPUS);
/* The processor is currently spinning, waiting
* for the xProcStart field to become non-zero
......@@ -266,8 +251,8 @@ static void __init smp_space_timers(unsigned int max_cpus)
unsigned long offset = tb_ticks_per_jiffy / max_cpus;
unsigned long previous_tb = paca[boot_cpuid].next_jiffy_update_tb;
for (i = 0; i < NR_CPUS; i++) {
if (cpu_possible(i) && i != boot_cpuid) {
for_each_cpu(i) {
if (i != boot_cpuid) {
paca[i].next_jiffy_update_tb =
previous_tb + offset;
previous_tb = paca[i].next_jiffy_update_tb;
......@@ -287,20 +272,25 @@ void vpa_init(int cpu)
register_vpa(flags, cpu, __pa((unsigned long)&(paca[cpu].xLpPaca)));
}
static void smp_xics_message_pass(int target, int msg, unsigned long data, int wait)
static inline void smp_xics_do_message(int cpu, int msg)
{
int i;
set_bit(msg, &xics_ipi_message[cpu].value);
mb();
xics_cause_IPI(cpu);
}
for (i = 0; i < NR_CPUS; ++i) {
if (!cpu_online(i))
continue;
static void smp_xics_message_pass(int target, int msg, unsigned long data, int wait)
{
unsigned int i;
if (target == MSG_ALL || target == i
|| (target == MSG_ALL_BUT_SELF
&& i != smp_processor_id())) {
set_bit(msg, &xics_ipi_message[i].value);
mb();
xics_cause_IPI(i);
if (target < NR_CPUS) {
smp_xics_do_message(target, msg);
} else {
for_each_online_cpu(i) {
if (target == MSG_ALL_BUT_SELF
&& i == smp_processor_id())
continue;
smp_xics_do_message(i, msg);
}
}
}
......@@ -309,18 +299,11 @@ extern void xics_request_IPIs(void);
static int __init smp_xics_probe(void)
{
int i;
int nr_cpus = 0;
for (i = 0; i < NR_CPUS; i++) {
if (cpu_possible(i))
nr_cpus++;
}
#ifdef CONFIG_SMP
xics_request_IPIs();
#endif
return nr_cpus;
return cpus_weight(cpu_possible_map);
}
static void __devinit smp_xics_setup_cpu(int cpu)
......@@ -660,6 +643,12 @@ int __devinit __cpu_up(unsigned int cpu)
paca[cpu].xCurrent = (u64)p;
current_set[cpu] = p->thread_info;
/* The information for processor bringup must
* be written out to main store before we release
* the processor.
*/
mb();
/* wake up cpus */
smp_ops->kick_cpu(cpu);
......
......@@ -475,9 +475,7 @@ void xics_init_IRQ(void)
if (systemcfg->platform == PLATFORM_PSERIES) {
#ifdef CONFIG_SMP
for (i = 0; i < NR_CPUS; ++i) {
if (!cpu_possible(i))
continue;
for_each_cpu(i) {
xics_per_cpu[i] = __ioremap((ulong)inodes[get_hard_smp_processor_id(i)].addr,
(ulong)inodes[get_hard_smp_processor_id(i)].size,
_PAGE_NO_CACHE);
......
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