[patch 10/32] [PATCH] smp: always reboot on cpu 0
From: Martin Schwidefsky
Date: Wed Feb 24 2010 - 03:50:46 EST
From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Always reboot on logical cpu 0. This makes sure that the IPL cpu is
always the same and usually avoids strange numbering schemes between
physical and logical cpus.
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---
arch/s390/include/asm/smp.h | 12 +++++++
arch/s390/kernel/Makefile | 2 +
arch/s390/kernel/ipl.c | 31 +++++++++++++++-----
arch/s390/kernel/machine_kexec.c | 10 +++++-
arch/s390/kernel/smp.c | 36 +++++++++++++++++++++++
arch/s390/kernel/switch_cpu.S | 59 +++++++++++++++++++++++++++++++++++++++
arch/s390/kernel/switch_cpu64.S | 52 ++++++++++++++++++++++++++++++++++
7 files changed, 191 insertions(+), 11 deletions(-)
Index: quilt-2.6/arch/s390/include/asm/smp.h
===================================================================
--- quilt-2.6.orig/arch/s390/include/asm/smp.h 2010-02-24 09:44:24.000000000 +0100
+++ quilt-2.6/arch/s390/include/asm/smp.h 2010-02-24 09:44:24.000000000 +0100
@@ -31,6 +31,18 @@
extern struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
+extern void smp_switch_to_ipl_cpu(void (*func)(void *), void *);
+extern void smp_switch_to_cpu(void (*)(void *), void *, unsigned long sp,
+ int from, int to);
+extern void smp_restart_cpu(void);
+
+#else /* CONFIG_SMP */
+
+static inline void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
+{
+ func(data);
+}
+
#endif /* CONFIG_SMP */
#ifdef CONFIG_HOTPLUG_CPU
Index: quilt-2.6/arch/s390/kernel/ipl.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/ipl.c 2010-02-24 09:28:13.000000000 +0100
+++ quilt-2.6/arch/s390/kernel/ipl.c 2010-02-24 09:44:24.000000000 +0100
@@ -553,7 +553,7 @@
return rc;
}
-static void ipl_run(struct shutdown_trigger *trigger)
+static void __ipl_run(void *unused)
{
diag308(DIAG308_IPL, NULL);
if (MACHINE_IS_VM)
@@ -562,6 +562,11 @@
reipl_ccw_dev(&ipl_info.data.ccw.dev_id);
}
+static void ipl_run(struct shutdown_trigger *trigger)
+{
+ smp_switch_to_ipl_cpu(__ipl_run, NULL);
+}
+
static int __init ipl_init(void)
{
int rc;
@@ -1039,7 +1044,7 @@
sprintf(dst + pos, " PARM %s", vmparm);
}
-static void reipl_run(struct shutdown_trigger *trigger)
+static void __reipl_run(void *unused)
{
struct ccw_dev_id devid;
static char buf[128];
@@ -1087,6 +1092,11 @@
disabled_wait((unsigned long) __builtin_return_address(0));
}
+static void reipl_run(struct shutdown_trigger *trigger)
+{
+ smp_switch_to_ipl_cpu(__reipl_run, NULL);
+}
+
static void reipl_block_ccw_init(struct ipl_parameter_block *ipb)
{
ipb->hdr.len = IPL_PARM_BLK_CCW_LEN;
@@ -1369,20 +1379,18 @@
static struct kset *dump_kset;
-static void dump_run(struct shutdown_trigger *trigger)
+static void __dump_run(void *unused)
{
struct ccw_dev_id devid;
static char buf[100];
switch (dump_method) {
case DUMP_METHOD_CCW_CIO:
- smp_send_stop();
devid.devno = dump_block_ccw->ipl_info.ccw.devno;
devid.ssid = 0;
reipl_ccw_dev(&devid);
break;
case DUMP_METHOD_CCW_VM:
- smp_send_stop();
sprintf(buf, "STORE STATUS");
__cpcmd(buf, NULL, 0, NULL);
sprintf(buf, "IPL %X", dump_block_ccw->ipl_info.ccw.devno);
@@ -1396,10 +1404,17 @@
diag308(DIAG308_SET, dump_block_fcp);
diag308(DIAG308_DUMP, NULL);
break;
- case DUMP_METHOD_NONE:
- return;
+ default:
+ break;
}
- printk(KERN_EMERG "Dump failed!\n");
+}
+
+static void dump_run(struct shutdown_trigger *trigger)
+{
+ if (dump_method == DUMP_METHOD_NONE)
+ return;
+ smp_send_stop();
+ smp_switch_to_ipl_cpu(__dump_run, NULL);
}
static int __init dump_ccw_init(void)
Index: quilt-2.6/arch/s390/kernel/machine_kexec.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/machine_kexec.c 2010-02-24 09:28:13.000000000 +0100
+++ quilt-2.6/arch/s390/kernel/machine_kexec.c 2010-02-24 09:44:24.000000000 +0100
@@ -54,11 +54,11 @@
{
}
-void machine_kexec(struct kimage *image)
+static void __machine_kexec(void *data)
{
relocate_kernel_t data_mover;
+ struct kimage *image = data;
- smp_send_stop();
pfault_fini();
s390_reset_system();
@@ -68,3 +68,9 @@
(*data_mover)(&image->head, image->start);
for (;;);
}
+
+void machine_kexec(struct kimage *image)
+{
+ smp_send_stop();
+ smp_switch_to_ipl_cpu(__machine_kexec, image);
+}
Index: quilt-2.6/arch/s390/kernel/Makefile
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/Makefile 2010-02-24 09:28:13.000000000 +0100
+++ quilt-2.6/arch/s390/kernel/Makefile 2010-02-24 09:44:24.000000000 +0100
@@ -32,6 +32,8 @@
obj-$(CONFIG_MODULES) += s390_ksyms.o module.o
obj-$(CONFIG_SMP) += smp.o topology.o
+obj-$(CONFIG_SMP) += $(if $(CONFIG_64BIT),switch_cpu64.o, \
+ switch_cpu.o)
obj-$(CONFIG_HIBERNATION) += suspend.o swsusp_asm64.o
obj-$(CONFIG_AUDIT) += audit.o
compat-obj-$(CONFIG_AUDIT) += compat_audit.o
Index: quilt-2.6/arch/s390/kernel/smp.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/smp.c 2010-02-24 09:44:24.000000000 +0100
+++ quilt-2.6/arch/s390/kernel/smp.c 2010-02-24 09:44:24.000000000 +0100
@@ -90,6 +90,39 @@
return 0;
}
+void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
+{
+ struct _lowcore *lc, *current_lc;
+ struct stack_frame *sf;
+ struct pt_regs *regs;
+ unsigned long sp;
+
+ if (smp_processor_id() == 0)
+ func(data);
+ __load_psw_mask(PSW_BASE_BITS | PSW_DEFAULT_KEY);
+ /* Disable lowcore protection */
+ __ctl_clear_bit(0, 28);
+ current_lc = lowcore_ptr[smp_processor_id()];
+ lc = lowcore_ptr[0];
+ if (!lc)
+ lc = current_lc;
+ lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
+ lc->restart_psw.addr = PSW_ADDR_AMODE | (unsigned long) smp_restart_cpu;
+ if (!cpu_online(0))
+ smp_switch_to_cpu(func, data, 0, stap(), __cpu_logical_map[0]);
+ while (signal_processor(0, sigp_stop_and_store_status) == sigp_busy)
+ cpu_relax();
+ sp = lc->panic_stack;
+ sp -= sizeof(struct pt_regs);
+ regs = (struct pt_regs *) sp;
+ memcpy(®s->gprs, ¤t_lc->gpregs_save_area, sizeof(regs->gprs));
+ memcpy(®s->psw, ¤t_lc->st_status_fixed_logout, sizeof(psw_t));
+ sp -= STACK_FRAME_OVERHEAD;
+ sf = (struct stack_frame *) sp;
+ sf->back_chain = regs->gprs[15];
+ smp_switch_to_cpu(func, data, sp, stap(), __cpu_logical_map[0]);
+}
+
void smp_send_stop(void)
{
int cpu, rc;
@@ -752,7 +785,8 @@
get_online_cpus();
mutex_lock(&smp_cpu_state_mutex);
rc = -EBUSY;
- if (cpu_online(cpu))
+ /* disallow configuration changes of online cpus and cpu 0 */
+ if (cpu_online(cpu) || cpu == 0)
goto out;
rc = 0;
switch (val) {
Index: quilt-2.6/arch/s390/kernel/switch_cpu64.S
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ quilt-2.6/arch/s390/kernel/switch_cpu64.S 2010-02-24 09:44:24.000000000 +0100
@@ -0,0 +1,52 @@
+/*
+ * 64-bit switch cpu code
+ *
+ * Copyright IBM Corp. 2009
+ *
+ */
+
+#include <asm/asm-offsets.h>
+#include <asm/lowcore.h>
+#include <asm/ptrace.h>
+
+# smp_switch_to_cpu switches to destination cpu and executes the passed function
+# Parameter: %r2 - function to call
+# %r3 - function parameter
+# %r4 - stack poiner
+# %r5 - current cpu
+# %r6 - destination cpu
+
+ .section .text
+ .align 4
+ .globl smp_switch_to_cpu
+smp_switch_to_cpu:
+ stmg %r6,%r15,__SF_GPRS(%r15)
+ lgr %r1,%r15
+ aghi %r15,-STACK_FRAME_OVERHEAD
+ stg %r1,__SF_BACKCHAIN(%r15)
+ larl %r1,.gprregs
+ stmg %r0,%r15,0(%r1)
+1: sigp %r0,%r6,__SIGP_RESTART /* start destination CPU */
+ brc 2,1b /* busy, try again */
+2: sigp %r0,%r5,__SIGP_STOP /* stop current CPU */
+ brc 2,2b /* busy, try again */
+3: j 3b
+
+ .globl smp_restart_cpu
+smp_restart_cpu:
+ larl %r1,.gprregs
+ lmg %r0,%r15,0(%r1)
+1: sigp %r0,%r5,__SIGP_SENSE /* Wait for calling CPU */
+ brc 10,1b /* busy, accepted (status 0), running */
+ tmll %r0,0x40 /* Test if calling CPU is stopped */
+ jz 1b
+ ltgr %r4,%r4 /* New stack ? */
+ jz 1f
+ lgr %r15,%r4
+1: basr %r14,%r2
+
+ .section .data,"aw",@progbits
+.gprregs:
+ .rept 16
+ .quad 0
+ .endr
Index: quilt-2.6/arch/s390/kernel/switch_cpu.S
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ quilt-2.6/arch/s390/kernel/switch_cpu.S 2010-02-24 09:44:24.000000000 +0100
@@ -0,0 +1,59 @@
+/*
+ * 31-bit switch cpu code
+ *
+ * Copyright IBM Corp. 2009
+ *
+ */
+
+#include <asm/asm-offsets.h>
+#include <asm/lowcore.h>
+#include <asm/ptrace.h>
+
+# smp_switch_to_cpu switches to destination cpu and executes the passed function
+# Parameter: %r2 - function to call
+# %r3 - function parameter
+# %r4 - stack poiner
+# %r5 - current cpu
+# %r6 - destination cpu
+
+ .section .text
+ .align 4
+ .globl smp_switch_to_cpu
+smp_switch_to_cpu:
+ stm %r6,%r15,__SF_GPRS(%r15)
+ lr %r1,%r15
+ ahi %r15,-STACK_FRAME_OVERHEAD
+ st %r1,__SF_BACKCHAIN(%r15)
+ basr %r13,0
+0: la %r1,.gprregs_addr-0b(%r13)
+ l %r1,0(%r1)
+ stm %r0,%r15,0(%r1)
+1: sigp %r0,%r6,__SIGP_RESTART /* start destination CPU */
+ brc 2,1b /* busy, try again */
+2: sigp %r0,%r5,__SIGP_STOP /* stop current CPU */
+ brc 2,2b /* busy, try again */
+3: j 3b
+
+ .globl smp_restart_cpu
+smp_restart_cpu:
+ basr %r13,0
+0: la %r1,.gprregs_addr-0b(%r13)
+ l %r1,0(%r1)
+ lm %r0,%r15,0(%r1)
+1: sigp %r0,%r5,__SIGP_SENSE /* Wait for calling CPU */
+ brc 10,1b /* busy, accepted (status 0), running */
+ tmll %r0,0x40 /* Test if calling CPU is stopped */
+ jz 1b
+ ltr %r4,%r4 /* New stack ? */
+ jz 1f
+ lr %r15,%r4
+1: basr %r14,%r2
+
+.gprregs_addr:
+ .long .gprregs
+
+ .section .data,"aw",@progbits
+.gprregs:
+ .rept 16
+ .long 0
+ .endr
--
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