kernel-fxtec-pro1x/arch/powerpc/platforms/86xx/mpc86xx_smp.c
Michael Ellerman e7a57273c6 powerpc: Allow create_branch() to return errors
Currently create_branch() creates a branch instruction for you, and
patches it into the call site.  In some circumstances it would be nice
to be able to create the instruction and patch it later, and also some
code might want to check for errors in the branch creation before
doing the patching.  A future commit will change create_branch() to
check for errors.

For callers that don't care, replace create_branch() with
patch_branch(), which just creates the branch and patches it directly.

While we're touching all the callers, change to using unsigned int *,
as this seems to match usage better.  That allows (and requires) us to
remove the volatile in the definition of vector in powermac/smp.c and
mpc86xx_smp.c, that's correct because now that we're passing vector as
an unsigned int * the compiler knows that it's value might change
across the patch_branch() call.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Jon Loeliger <jdl@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01 11:28:19 +10:00

114 lines
2.5 KiB
C

/*
* Author: Xianghua Xiao <x.xiao@freescale.com>
* Zhang Wei <wei.zhang@freescale.com>
*
* Copyright 2006 Freescale Semiconductor 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.
*/
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/code-patching.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/pci-bridge.h>
#include <asm-powerpc/mpic.h>
#include <asm/mpc86xx.h>
#include <asm/cacheflush.h>
#include <sysdev/fsl_soc.h>
#include "mpc86xx.h"
extern void __secondary_start_mpc86xx(void);
extern unsigned long __secondary_hold_acknowledge;
static void __init
smp_86xx_release_core(int nr)
{
__be32 __iomem *mcm_vaddr;
unsigned long pcr;
if (nr < 0 || nr >= NR_CPUS)
return;
/*
* Startup Core #nr.
*/
mcm_vaddr = ioremap(get_immrbase() + MPC86xx_MCM_OFFSET,
MPC86xx_MCM_SIZE);
pcr = in_be32(mcm_vaddr + (MCM_PORT_CONFIG_OFFSET >> 2));
pcr |= 1 << (nr + 24);
out_be32(mcm_vaddr + (MCM_PORT_CONFIG_OFFSET >> 2), pcr);
}
static void __init
smp_86xx_kick_cpu(int nr)
{
unsigned int save_vector;
unsigned long target, flags;
int n = 0;
unsigned int *vector = (unsigned int *)(KERNELBASE + 0x100);
if (nr < 0 || nr >= NR_CPUS)
return;
pr_debug("smp_86xx_kick_cpu: kick CPU #%d\n", nr);
local_irq_save(flags);
/* Save reset vector */
save_vector = *vector;
/* Setup fake reset vector to call __secondary_start_mpc86xx. */
target = (unsigned long) __secondary_start_mpc86xx;
patch_branch(vector, target, BRANCH_SET_LINK);
/* Kick that CPU */
smp_86xx_release_core(nr);
/* Wait a bit for the CPU to take the exception. */
while ((__secondary_hold_acknowledge != nr) && (n++, n < 1000))
mdelay(1);
/* Restore the exception vector */
*vector = save_vector;
flush_icache_range((unsigned long) vector, (unsigned long) vector + 4);
local_irq_restore(flags);
pr_debug("wait CPU #%d for %d msecs.\n", nr, n);
}
static void __init
smp_86xx_setup_cpu(int cpu_nr)
{
mpic_setup_this_cpu();
}
struct smp_ops_t smp_86xx_ops = {
.message_pass = smp_mpic_message_pass,
.probe = smp_mpic_probe,
.kick_cpu = smp_86xx_kick_cpu,
.setup_cpu = smp_86xx_setup_cpu,
.take_timebase = smp_generic_take_timebase,
.give_timebase = smp_generic_give_timebase,
};
void __init
mpc86xx_smp_init(void)
{
smp_ops = &smp_86xx_ops;
}