kernel-fxtec-pro1x/arch/mips/sibyte/sb1250/smp.c
Peter Zijlstra 184748cc50 sched: Provide scheduler_ipi() callback in response to smp_send_reschedule()
For future rework of try_to_wake_up() we'd like to push part of that
function onto the CPU the task is actually going to run on.

In order to do so we need a generic callback from the existing scheduler IPI.

This patch introduces such a generic callback: scheduler_ipi() and
implements it as a NOP.

BenH notes: PowerPC might use this IPI on offline CPUs under rare conditions!

Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110405152728.744338123@chello.nl
2011-04-14 08:52:32 +02:00

186 lines
4.7 KiB
C

/*
* Copyright (C) 2001, 2002, 2003 Broadcom Corporation
*
* 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.
*/
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/smp.h>
#include <linux/kernel_stat.h>
#include <linux/sched.h>
#include <asm/mmu_context.h>
#include <asm/io.h>
#include <asm/fw/cfe/cfe_api.h>
#include <asm/sibyte/sb1250.h>
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/sb1250_int.h>
static void *mailbox_set_regs[] = {
IOADDR(A_IMR_CPU0_BASE + R_IMR_MAILBOX_SET_CPU),
IOADDR(A_IMR_CPU1_BASE + R_IMR_MAILBOX_SET_CPU)
};
static void *mailbox_clear_regs[] = {
IOADDR(A_IMR_CPU0_BASE + R_IMR_MAILBOX_CLR_CPU),
IOADDR(A_IMR_CPU1_BASE + R_IMR_MAILBOX_CLR_CPU)
};
static void *mailbox_regs[] = {
IOADDR(A_IMR_CPU0_BASE + R_IMR_MAILBOX_CPU),
IOADDR(A_IMR_CPU1_BASE + R_IMR_MAILBOX_CPU)
};
/*
* SMP init and finish on secondary CPUs
*/
void __cpuinit sb1250_smp_init(void)
{
unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
STATUSF_IP1 | STATUSF_IP0;
/* Set interrupt mask, but don't enable */
change_c0_status(ST0_IM, imask);
}
/*
* These are routines for dealing with the sb1250 smp capabilities
* independent of board/firmware
*/
/*
* Simple enough; everything is set up, so just poke the appropriate mailbox
* register, and we should be set
*/
static void sb1250_send_ipi_single(int cpu, unsigned int action)
{
__raw_writeq((((u64)action) << 48), mailbox_set_regs[cpu]);
}
static inline void sb1250_send_ipi_mask(const struct cpumask *mask,
unsigned int action)
{
unsigned int i;
for_each_cpu(i, mask)
sb1250_send_ipi_single(i, action);
}
/*
* Code to run on secondary just after probing the CPU
*/
static void __cpuinit sb1250_init_secondary(void)
{
extern void sb1250_smp_init(void);
sb1250_smp_init();
}
/*
* Do any tidying up before marking online and running the idle
* loop
*/
static void __cpuinit sb1250_smp_finish(void)
{
extern void sb1250_clockevent_init(void);
sb1250_clockevent_init();
local_irq_enable();
}
/*
* Final cleanup after all secondaries booted
*/
static void sb1250_cpus_done(void)
{
}
/*
* Setup the PC, SP, and GP of a secondary processor and start it
* running!
*/
static void __cpuinit sb1250_boot_secondary(int cpu, struct task_struct *idle)
{
int retval;
retval = cfe_cpu_start(cpu_logical_map(cpu), &smp_bootstrap,
__KSTK_TOS(idle),
(unsigned long)task_thread_info(idle), 0);
if (retval != 0)
printk("cfe_start_cpu(%i) returned %i\n" , cpu, retval);
}
/*
* Use CFE to find out how many CPUs are available, setting up
* cpu_possible_map and the logical/physical mappings.
* XXXKW will the boot CPU ever not be physical 0?
*
* Common setup before any secondaries are started
*/
static void __init sb1250_smp_setup(void)
{
int i, num;
cpus_clear(cpu_possible_map);
cpu_set(0, cpu_possible_map);
__cpu_number_map[0] = 0;
__cpu_logical_map[0] = 0;
for (i = 1, num = 0; i < NR_CPUS; i++) {
if (cfe_cpu_stop(i) == 0) {
cpu_set(i, cpu_possible_map);
__cpu_number_map[i] = ++num;
__cpu_logical_map[num] = i;
}
}
printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
}
static void __init sb1250_prepare_cpus(unsigned int max_cpus)
{
}
struct plat_smp_ops sb_smp_ops = {
.send_ipi_single = sb1250_send_ipi_single,
.send_ipi_mask = sb1250_send_ipi_mask,
.init_secondary = sb1250_init_secondary,
.smp_finish = sb1250_smp_finish,
.cpus_done = sb1250_cpus_done,
.boot_secondary = sb1250_boot_secondary,
.smp_setup = sb1250_smp_setup,
.prepare_cpus = sb1250_prepare_cpus,
};
void sb1250_mailbox_interrupt(void)
{
int cpu = smp_processor_id();
int irq = K_INT_MBOX_0;
unsigned int action;
kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
/* Load the mailbox register to figure out what we're supposed to do */
action = (____raw_readq(mailbox_regs[cpu]) >> 48) & 0xffff;
/* Clear the mailbox to clear the interrupt */
____raw_writeq(((u64)action) << 48, mailbox_clear_regs[cpu]);
if (action & SMP_RESCHEDULE_YOURSELF)
scheduler_ipi();
if (action & SMP_CALL_FUNCTION)
smp_call_function_interrupt();
}