From: "Steven J. Hill" <Steven.Hill@xxxxxxxxxx>
Adds support for CPU hotplugging on the Malta platform.
Signed-off-by: Steven J. Hill <Steven.Hill@xxxxxxxxxx>
---
arch/mips/include/asm/amon.h | 1 +
arch/mips/mti-malta/malta-amon.c | 107 +++++++++++++++++++++++++++++++-------
arch/mips/mti-malta/malta-int.c | 2 +-
3 files changed, 91 insertions(+), 19 deletions(-)
diff --git a/arch/mips/include/asm/amon.h b/arch/mips/include/asm/amon.h
index 3cc03c6..a71e82d 100644
--- a/arch/mips/include/asm/amon.h
+++ b/arch/mips/include/asm/amon.h
@@ -10,3 +10,4 @@
int amon_cpu_avail(int cpu);
int amon_cpu_start(int cpu, unsigned long pc, unsigned long sp,
unsigned long gp, unsigned long a0);
+void amon_cpu_dead(void);
diff --git a/arch/mips/mti-malta/malta-amon.c b/arch/mips/mti-malta/malta-amon.c
index 0319ad8..80ad67a 100644
--- a/arch/mips/mti-malta/malta-amon.c
+++ b/arch/mips/mti-malta/malta-amon.c
@@ -3,10 +3,10 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
+ * Arbitrary Monitor Interface
+ *
* Copyright (C) 2007 MIPS Technologies, Inc. All rights reserved.
* Copyright (C) 2013 Imagination Technologies Ltd.
- *
- * Arbitrary Monitor Interface
*/
#include <linux/kernel.h>
#include <linux/init.h>
@@ -22,40 +22,49 @@ 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);
+ pr_debug("%s: CPU%d is out of range\n", __func__, 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;
+ if (launch->flags == LAUNCH_FREADY) {
+ pr_debug("%s: CPU%d is available\n", __func__, cpu);
+ return LAUNCH_FREADY;
+ } else if (launch->flags & LAUNCH_FGONE) {
+ pr_debug("%s: CPU%d is already gone\n", __func__, cpu);
+ return LAUNCH_FGONE;
+ } else if (launch->flags & LAUNCH_FGO) {
+ pr_debug("%s: CPU%d is going\n", __func__, cpu);
+ return LAUNCH_FGO;
+ } else {
+ pr_debug("%s: CPU%d is unavailable\n", __func__, cpu);
+ return 0;
+ }
}
int amon_cpu_start(int cpu,
- unsigned long pc, unsigned long sp,
- unsigned long gp, unsigned long a0)
+ unsigned long pc, unsigned long sp,
+ unsigned long gp, unsigned long a0)
{
+ int this_cpu;
volatile struct cpulaunch *launch =
(struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
if (!amon_cpu_avail(cpu))
return -1;
- if (cpu == smp_processor_id()) {
+
+ preempt_disable();
+ this_cpu = smp_processor_id();
+ preempt_enable();
+
+ if (cpu == this_cpu) {
pr_debug("launch: I am cpu%d!\n", cpu);
return -1;
}
- launch += cpu;
pr_debug("launch: starting cpu%d\n", cpu);
+ launch += cpu;
launch->pc = pc;
launch->gp = gp;
launch->sp = sp;
@@ -67,12 +76,74 @@ int amon_cpu_start(int cpu,
while ((launch->flags & LAUNCH_FGONE) == 0)
;
- smp_rmb(); /* Target will be updating flags soon */
+ smp_rmb(); /* Target will be updating flags soon */
pr_debug("launch: cpu%d gone!\n", cpu);
return 0;
}
+/*
+ * Restart the CPU ready for amon_cpu_start again
+ * A bit of a hack... it duplicates the CPU startup code that
+ * lives somewhere in the boot monitor.
+ */
+void amon_cpu_dead(void)
+{
+ struct cpulaunch *launch;
+ unsigned int r0;
+ int cpufreq;
+
+ launch = (struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
+ launch += smp_processor_id();
+
+ launch->pc = 0;
+ launch->gp = 0;
+ launch->sp = 0;
+ launch->a0 = 0;
+ launch->flags = LAUNCH_FREADY;
+
+ cpufreq = 500000000; /* FIXME: Correct value? */
+
+ __asm__ __volatile__ (
+ " .set push\n\t"
+ " .set noreorder\n\t"
+ "1:\n\t"
+ " lw %[r0],%[LAUNCH_FLAGS](%[launch])\n\t"
+ " andi %[r0],%[FGO]\n\t"
+ " bnez %[r0],1f\n\t"
+ " nop\n\t"
+ " mfc0 %[r0],$9\n\t" /* Read Count */
+ " addu %[r0],%[waitperiod]\n\t"
+ " mtc0 %[r0],$11\n\t" /* Write Compare */
+ " wait\n\t"
+ " b 1b\n\t"
+ " nop\n\t"
+ "1: lw $ra,%[LAUNCH_PC](%[launch])\n\t"
+ " lw $gp,%[LAUNCH_GP](%[launch])\n\t"
+ " lw $sp,%[LAUNCH_SP](%[launch])\n\t"
+ " lw $a0,%[LAUNCH_A0](%[launch])\n\t"
+ " move $a1,$zero\n\t"
+ " move $a2,$zero\n\t"
+ " move $a3,$zero\n\t"
+ " lw %[r0],%[LAUNCH_FLAGS](%[launch])\n\t"
+ " ori %[r0],%[FGONE]\n\t"
+ " jr $ra\n\t"
+ " sw %[r0],%[LAUNCH_FLAGS](%[launch])\n\t"
+ " .set pop\n\t"
+ : [r0] "=&r" (r0)
+ : [launch] "r" (launch),
+ [FGONE] "i" (LAUNCH_FGONE),
+ [FGO] "i" (LAUNCH_FGO),
+ [LAUNCH_PC] "i" (offsetof(struct cpulaunch, pc)),
+ [LAUNCH_GP] "i" (offsetof(struct cpulaunch, gp)),
+ [LAUNCH_SP] "i" (offsetof(struct cpulaunch, sp)),
+ [LAUNCH_A0] "i" (offsetof(struct cpulaunch, a0)),
+ [LAUNCH_FLAGS] "i" (offsetof(struct cpulaunch, flags)),
+ [waitperiod] "i" ((cpufreq / 2) / 100) /* delay of ~10ms */
+ : "ra", "a0", "a1", "a2", "a3", "sp" /* ,"gp" */
+ );
+}
+
#ifdef CONFIG_MIPS_VPE_LOADER
int vpe_run(struct vpe *v)
{
diff --git a/arch/mips/mti-malta/malta-int.c b/arch/mips/mti-malta/malta-int.c
index ca3e3a4..136c4fc 100644
--- a/arch/mips/mti-malta/malta-int.c
+++ b/arch/mips/mti-malta/malta-int.c
@@ -39,7 +39,7 @@
int gcmp_present = -1;
static unsigned long _msc01_biu_base;
-static unsigned long _gcmp_base;
+unsigned long _gcmp_base;
static unsigned int ipi_map[NR_CPUS];
static DEFINE_RAW_SPINLOCK(mips_irq_lock);
--
1.7.10.4
