android_kernel_xiaomi_sm8350/arch/powerpc/platforms/cell/pervasive.c
Arnd Bergmann 3addf55c94 [POWERPC] cell: Support pinhole-reset on IBM cell blades
The Cell Broadband Engine has a method of injecting a
system-reset-exception from an external source into the
operating system, which should trigger the regular behaviour
of entering xmon or kdump.

Unfortunately, the exception handler cannot distinguish it from
other interrupt causes by the SRR1 register, which gets used
for this on Power 6 and others.

IBM Blade servers that want to support triggering the
system reset exception using a pinhole button in the front
panel therefore use an extra register to determine the
reset cause.

Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>

--
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-08-25 16:58:26 +10:00

158 lines
3.8 KiB
C

/*
* CBE Pervasive Monitor and Debug
*
* (C) Copyright IBM Corporation 2005
*
* Authors: Maximino Aguilar (maguilar@us.ibm.com)
* Michael N. Day (mnday@us.ibm.com)
*
* 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#undef DEBUG
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/percpu.h>
#include <linux/types.h>
#include <linux/kallsyms.h>
#include <asm/io.h>
#include <asm/machdep.h>
#include <asm/prom.h>
#include <asm/pgtable.h>
#include <asm/reg.h>
#include "pervasive.h"
#include "cbe_regs.h"
static int sysreset_hack;
static void cbe_power_save(void)
{
unsigned long ctrl, thread_switch_control;
/*
* We need to hard disable interrupts, the local_irq_enable() done by
* our caller upon return will hard re-enable.
*/
hard_irq_disable();
ctrl = mfspr(SPRN_CTRLF);
/* Enable DEC and EE interrupt request */
thread_switch_control = mfspr(SPRN_TSC_CELL);
thread_switch_control |= TSC_CELL_EE_ENABLE | TSC_CELL_EE_BOOST;
switch (ctrl & CTRL_CT) {
case CTRL_CT0:
thread_switch_control |= TSC_CELL_DEC_ENABLE_0;
break;
case CTRL_CT1:
thread_switch_control |= TSC_CELL_DEC_ENABLE_1;
break;
default:
printk(KERN_WARNING "%s: unknown configuration\n",
__FUNCTION__);
break;
}
mtspr(SPRN_TSC_CELL, thread_switch_control);
/*
* go into low thread priority, medium priority will be
* restored for us after wake-up.
*/
HMT_low();
/*
* atomically disable thread execution and runlatch.
* External and Decrementer exceptions are still handled when the
* thread is disabled but now enter in cbe_system_reset_exception()
*/
ctrl &= ~(CTRL_RUNLATCH | CTRL_TE);
mtspr(SPRN_CTRLT, ctrl);
}
static int cbe_system_reset_exception(struct pt_regs *regs)
{
int cpu;
struct cbe_pmd_regs __iomem *pmd;
switch (regs->msr & SRR1_WAKEMASK) {
case SRR1_WAKEEE:
do_IRQ(regs);
break;
case SRR1_WAKEDEC:
timer_interrupt(regs);
break;
case SRR1_WAKEMT:
/*
* The BMC can inject user triggered system reset exceptions,
* but cannot set the system reset reason in srr1,
* so check an extra register here.
*/
if (sysreset_hack && (cpu = smp_processor_id()) == 0) {
pmd = cbe_get_cpu_pmd_regs(cpu);
if (in_be64(&pmd->ras_esc_0) & 0xffff) {
out_be64(&pmd->ras_esc_0, 0);
return 0;
}
}
break;
#ifdef CONFIG_CBE_RAS
case SRR1_WAKESYSERR:
cbe_system_error_exception(regs);
break;
case SRR1_WAKETHERM:
cbe_thermal_exception(regs);
break;
#endif /* CONFIG_CBE_RAS */
default:
/* do system reset */
return 0;
}
/* everything handled */
return 1;
}
void __init cbe_pervasive_init(void)
{
int cpu;
if (!cpu_has_feature(CPU_FTR_PAUSE_ZERO))
return;
sysreset_hack = machine_is_compatible("IBM,CBPLUS-1.0");
for_each_possible_cpu(cpu) {
struct cbe_pmd_regs __iomem *regs = cbe_get_cpu_pmd_regs(cpu);
if (!regs)
continue;
/* Enable Pause(0) control bit */
out_be64(&regs->pmcr, in_be64(&regs->pmcr) |
CBE_PMD_PAUSE_ZERO_CONTROL);
/* Enable JTAG system-reset hack */
if (sysreset_hack)
out_be32(&regs->fir_mode_reg,
in_be32(&regs->fir_mode_reg) |
CBE_PMD_FIR_MODE_M8);
}
ppc_md.power_save = cbe_power_save;
ppc_md.system_reset_exception = cbe_system_reset_exception;
}