satip-axe/kernel/arch/mips/mti-malta/malta-amon.c

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/*
* Copyright (C) 2007 MIPS Technologies, Inc.
* All rights reserved.
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*
* Arbitrary Monitor interface
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <asm/addrspace.h>
#include <asm/mips-boards/launch.h>
#include <asm/mipsmtregs.h>
int amon_cpu_avail(int cpu)
{
struct cpulaunch *launch = (struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
if (cpu < 0 || cpu >= NCPULAUNCH) {
pr_debug("avail: cpu%d is out of range\n", cpu);
return 0;
}
launch += cpu;
if (!(launch->flags & LAUNCH_FREADY)) {
pr_debug("avail: cpu%d is not ready\n", cpu);
return 0;
}
if (launch->flags & (LAUNCH_FGO|LAUNCH_FGONE)) {
pr_debug("avail: too late.. cpu%d is already gone\n", cpu);
return 0;
}
return 1;
}
void amon_cpu_start(int cpu,
unsigned long pc, unsigned long sp,
unsigned long gp, unsigned long a0)
{
volatile struct cpulaunch *launch =
(struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
if (!amon_cpu_avail(cpu))
return;
if (cpu == smp_processor_id()) {
pr_debug("launch: I am cpu%d!\n", cpu);
return;
}
launch += cpu;
pr_debug("launch: starting cpu%d\n", cpu);
launch->pc = pc;
launch->gp = gp;
launch->sp = sp;
launch->a0 = a0;
smp_wmb(); /* Target must see parameters before go */
launch->flags |= LAUNCH_FGO;
smp_wmb(); /* Target must see go before we poll */
while ((launch->flags & LAUNCH_FGONE) == 0)
;
smp_rmb(); /* Target will be updating flags soon */
pr_debug("launch: cpu%d gone!\n", cpu);
}