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linux/arch/powerpc/platforms/iseries/smp.c
David Gibson 3356bb9f7b [PATCH] powerpc: Remove lppaca structure from the PACA
At present the lppaca - the structure shared with the iSeries
hypervisor and phyp - is contained within the PACA, our own low-level
per-cpu structure.  This doesn't have to be so, the patch below
removes it, making a separate array of lppaca structures.

This saves approximately 500*NR_CPUS bytes of image size and kernel
memory, because we don't need aligning gap between the Linux and
hypervisor portions of every PACA.  On the other hand it means an
extra level of dereference in many accesses to the lppaca.

The patch also gets rid of several places where we assign the paca
address to a local variable for no particular reason.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:17:39 +11:00

121 lines
2.7 KiB
C

/*
* SMP support for iSeries machines.
*
* Dave Engebretsen, Peter Bergner, and
* Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
*
* Plus various changes from other IBM teams...
*
* 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.
*/
#undef DEBUG
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.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/cache.h>
#include <linux/err.h>
#include <linux/sysdev.h>
#include <linux/cpu.h>
#include <asm/ptrace.h>
#include <asm/atomic.h>
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/paca.h>
#include <asm/iseries/hv_call.h>
#include <asm/time.h>
#include <asm/machdep.h>
#include <asm/cputable.h>
#include <asm/system.h>
static unsigned long iSeries_smp_message[NR_CPUS];
void iSeries_smp_message_recv(struct pt_regs *regs)
{
int cpu = smp_processor_id();
int msg;
if (num_online_cpus() < 2)
return;
for (msg = 0; msg < 4; msg++)
if (test_and_clear_bit(msg, &iSeries_smp_message[cpu]))
smp_message_recv(msg, regs);
}
static inline void smp_iSeries_do_message(int cpu, int msg)
{
set_bit(msg, &iSeries_smp_message[cpu]);
HvCall_sendIPI(&(paca[cpu]));
}
static void smp_iSeries_message_pass(int target, int msg)
{
int 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);
}
}
}
static int smp_iSeries_probe(void)
{
return cpus_weight(cpu_possible_map);
}
static void smp_iSeries_kick_cpu(int nr)
{
BUG_ON((nr < 0) || (nr >= NR_CPUS));
/* Verify that our partition has a processor nr */
if (lppaca[nr].dyn_proc_status >= 2)
return;
/* The processor is currently spinning, waiting
* for the cpu_start field to become non-zero
* After we set cpu_start, the processor will
* continue on to secondary_start in iSeries_head.S
*/
paca[nr].cpu_start = 1;
}
static void __devinit smp_iSeries_setup_cpu(int nr)
{
}
static struct smp_ops_t iSeries_smp_ops = {
.message_pass = smp_iSeries_message_pass,
.probe = smp_iSeries_probe,
.kick_cpu = smp_iSeries_kick_cpu,
.setup_cpu = smp_iSeries_setup_cpu,
};
/* This is called very early. */
void __init smp_init_iSeries(void)
{
smp_ops = &iSeries_smp_ops;
}