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Merge branch 'kexec' into next

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This commit is contained in:
Benjamin Herrenschmidt 2011-12-16 11:09:21 +11:00
commit 43ca5d347a
6 changed files with 219 additions and 208 deletions
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7
arch/powerpc/include/asm/kexec.h
View File

@ -49,7 +49,6 @@
#define KEXEC_STATE_REAL_MODE 2
#ifndef __ASSEMBLY__
#include <linux/cpumask.h>
#include <asm/reg.h>
typedef void (*crash_shutdown_t)(void);
@ -73,11 +72,6 @@ extern void kexec_smp_wait(void); /* get and clear naca physid, wait for
master to copy new code to 0 */
extern int crashing_cpu;
extern void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *));
extern cpumask_t cpus_in_sr;
static inline int kexec_sr_activated(int cpu)
{
return cpumask_test_cpu(cpu, &cpus_in_sr);
}
struct kimage;
struct pt_regs;
@ -94,7 +88,6 @@ extern void reserve_crashkernel(void);
extern void machine_kexec_mask_interrupts(void);
#else /* !CONFIG_KEXEC */
static inline int kexec_sr_activated(int cpu) { return 0; }
static inline void crash_kexec_secondary(struct pt_regs *regs) { }
static inline int overlaps_crashkernel(unsigned long start, unsigned long size)

2
arch/powerpc/include/asm/system.h
View File

@ -193,8 +193,8 @@ extern void cacheable_memzero(void *p, unsigned int nb);
extern void *cacheable_memcpy(void *, const void *, unsigned int);
extern int do_page_fault(struct pt_regs *, unsigned long, unsigned long);
extern void bad_page_fault(struct pt_regs *, unsigned long, int);
extern int die(const char *, struct pt_regs *, long);
extern void _exception(int, struct pt_regs *, int, unsigned long);
extern void die(const char *, struct pt_regs *, long);
extern void _nmask_and_or_msr(unsigned long nmask, unsigned long or_val);
#ifdef CONFIG_BOOKE_WDT

220
arch/powerpc/kernel/crash.c
View File

@ -10,85 +10,85 @@
*
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/reboot.h>
#include <linux/kexec.h>
#include <linux/bootmem.h>
#include <linux/export.h>
#include <linux/crash_dump.h>
#include <linux/delay.h>
#include <linux/elf.h>
#include <linux/elfcore.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/types.h>
#include <linux/memblock.h>
#include <asm/processor.h>
#include <asm/machdep.h>
#include <asm/kexec.h>
#include <asm/kdump.h>
#include <asm/prom.h>
#include <asm/firmware.h>
#include <asm/smp.h>
#include <asm/system.h>
#include <asm/setjmp.h>
#ifdef DEBUG
#include <asm/udbg.h>
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif
/*
* The primary CPU waits a while for all secondary CPUs to enter. This is to
* avoid sending an IPI if the secondary CPUs are entering
* crash_kexec_secondary on their own (eg via a system reset).
*
* The secondary timeout has to be longer than the primary. Both timeouts are
* in milliseconds.
*/
#define PRIMARY_TIMEOUT 500
#define SECONDARY_TIMEOUT 1000
/* This keeps a track of which one is crashing cpu. */
#define IPI_TIMEOUT 10000
#define REAL_MODE_TIMEOUT 10000
/* This keeps a track of which one is the crashing cpu. */
int crashing_cpu = -1;
static cpumask_t cpus_in_crash = CPU_MASK_NONE;
cpumask_t cpus_in_sr = CPU_MASK_NONE;
static atomic_t cpus_in_crash;
static int time_to_dump;
#define CRASH_HANDLER_MAX 3
/* NULL terminated list of shutdown handles */
static crash_shutdown_t crash_shutdown_handles[CRASH_HANDLER_MAX+1];
static DEFINE_SPINLOCK(crash_handlers_lock);
static unsigned long crash_shutdown_buf[JMP_BUF_LEN];
static int crash_shutdown_cpu = -1;
static int handle_fault(struct pt_regs *regs)
{
if (crash_shutdown_cpu == smp_processor_id())
longjmp(crash_shutdown_buf, 1);
return 0;
}
#ifdef CONFIG_SMP
static atomic_t enter_on_soft_reset = ATOMIC_INIT(0);
void crash_ipi_callback(struct pt_regs *regs)
{
static cpumask_t cpus_state_saved = CPU_MASK_NONE;
int cpu = smp_processor_id();
if (!cpu_online(cpu))
return;
hard_irq_disable();
if (!cpumask_test_cpu(cpu, &cpus_in_crash))
if (!cpumask_test_cpu(cpu, &cpus_state_saved)) {
crash_save_cpu(regs, cpu);
cpumask_set_cpu(cpu, &cpus_in_crash);
/*
* Entered via soft-reset - could be the kdump
* process is invoked using soft-reset or user activated
* it if some CPU did not respond to an IPI.
* For soft-reset, the secondary CPU can enter this func
* twice. 1 - using IPI, and 2. soft-reset.
* Tell the kexec CPU that entered via soft-reset and ready
* to go down.
*/
if (cpumask_test_cpu(cpu, &cpus_in_sr)) {
cpumask_clear_cpu(cpu, &cpus_in_sr);
atomic_inc(&enter_on_soft_reset);
cpumask_set_cpu(cpu, &cpus_state_saved);
}
atomic_inc(&cpus_in_crash);
smp_mb__after_atomic_inc();
/*
* Starting the kdump boot.
* This barrier is needed to make sure that all CPUs are stopped.
* If not, soft-reset will be invoked to bring other CPUs.
*/
while (!cpumask_test_cpu(crashing_cpu, &cpus_in_crash))
while (!time_to_dump)
cpu_relax();
if (ppc_md.kexec_cpu_down)
@ -103,106 +103,99 @@ void crash_ipi_callback(struct pt_regs *regs)
/* NOTREACHED */
}
/*
* Wait until all CPUs are entered via soft-reset.
*/
static void crash_soft_reset_check(int cpu)
{
unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
cpumask_clear_cpu(cpu, &cpus_in_sr);
while (atomic_read(&enter_on_soft_reset) != ncpus)
cpu_relax();
}
static void crash_kexec_prepare_cpus(int cpu)
{
unsigned int msecs;
unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
int tries = 0;
int (*old_handler)(struct pt_regs *regs);
printk(KERN_EMERG "Sending IPI to other CPUs\n");
crash_send_ipi(crash_ipi_callback);
smp_wmb();
again:
/*
* FIXME: Until we will have the way to stop other CPUs reliably,
* the crash CPU will send an IPI and wait for other CPUs to
* respond.
* Delay of at least 10 seconds.
*/
printk(KERN_EMERG "Sending IPI to other cpus...\n");
msecs = 10000;
while ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) {
cpu_relax();
msecs = IPI_TIMEOUT;
while ((atomic_read(&cpus_in_crash) < ncpus) && (--msecs > 0))
mdelay(1);
}
/* Would it be better to replace the trap vector here? */
if (atomic_read(&cpus_in_crash) >= ncpus) {
printk(KERN_EMERG "IPI complete\n");
return;
}
printk(KERN_EMERG "ERROR: %d cpu(s) not responding\n",
ncpus - atomic_read(&cpus_in_crash));
/*
* FIXME: In case if we do not get all CPUs, one possibility: ask the
* user to do soft reset such that we get all.
* Soft-reset will be used until better mechanism is implemented.
* If we have a panic timeout set then we can't wait indefinitely
* for someone to activate system reset. We also give up on the
* second time through if system reset fail to work.
*/
if (cpumask_weight(&cpus_in_crash) < ncpus) {
printk(KERN_EMERG "done waiting: %d cpu(s) not responding\n",
ncpus - cpumask_weight(&cpus_in_crash));
printk(KERN_EMERG "Activate soft-reset to stop other cpu(s)\n");
cpumask_clear(&cpus_in_sr);
atomic_set(&enter_on_soft_reset, 0);
while (cpumask_weight(&cpus_in_crash) < ncpus)
if ((panic_timeout > 0) || (tries > 0))
return;
/*
* A system reset will cause all CPUs to take an 0x100 exception.
* The primary CPU returns here via setjmp, and the secondary
* CPUs reexecute the crash_kexec_secondary path.
*/
old_handler = __debugger;
__debugger = handle_fault;
crash_shutdown_cpu = smp_processor_id();
if (setjmp(crash_shutdown_buf) == 0) {
printk(KERN_EMERG "Activate system reset (dumprestart) "
"to stop other cpu(s)\n");
/*
* A system reset will force all CPUs to execute the
* crash code again. We need to reset cpus_in_crash so we
* wait for everyone to do this.
*/
atomic_set(&cpus_in_crash, 0);
smp_mb();
while (atomic_read(&cpus_in_crash) < ncpus)
cpu_relax();
}
/*
* Make sure all CPUs are entered via soft-reset if the kdump is
* invoked using soft-reset.
*/
if (cpumask_test_cpu(cpu, &cpus_in_sr))
crash_soft_reset_check(cpu);
/* Leave the IPI callback set */
crash_shutdown_cpu = -1;
__debugger = old_handler;
tries++;
goto again;
}
/*
* This function will be called by secondary cpus or by kexec cpu
* if soft-reset is activated to stop some CPUs.
* This function will be called by secondary cpus.
*/
void crash_kexec_secondary(struct pt_regs *regs)
{
int cpu = smp_processor_id();
unsigned long flags;
int msecs = 5;
int msecs = SECONDARY_TIMEOUT;
local_irq_save(flags);
/* Wait 5ms if the kexec CPU is not entered yet. */
/* Wait for the primary crash CPU to signal its progress */
while (crashing_cpu < 0) {
if (--msecs < 0) {
/*
* Either kdump image is not loaded or
* kdump process is not started - Probably xmon
* exited using 'x'(exit and recover) or
* kexec_should_crash() failed for all running tasks.
*/
cpumask_clear_cpu(cpu, &cpus_in_sr);
/* No response, kdump image may not have been loaded */
local_irq_restore(flags);
return;
}
mdelay(1);
cpu_relax();
}
if (cpu == crashing_cpu) {
/*
* Panic CPU will enter this func only via soft-reset.
* Wait until all secondary CPUs entered and
* then start kexec boot.
*/
crash_soft_reset_check(cpu);
cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
if (ppc_md.kexec_cpu_down)
ppc_md.kexec_cpu_down(1, 0);
machine_kexec(kexec_crash_image);
/* NOTREACHED */
}
crash_ipi_callback(regs);
}
@ -211,7 +204,7 @@ void crash_kexec_secondary(struct pt_regs *regs)
static void crash_kexec_prepare_cpus(int cpu)
{
/*
* move the secondarys to us so that we can copy
* move the secondaries to us so that we can copy
* the new kernel 0-0x100 safely
*
* do this if kexec in setup.c ?
@ -225,7 +218,6 @@ static void crash_kexec_prepare_cpus(int cpu)
void crash_kexec_secondary(struct pt_regs *regs)
{
cpumask_clear(&cpus_in_sr);
}
#endif /* CONFIG_SMP */
@ -236,7 +228,7 @@ static void crash_kexec_wait_realmode(int cpu)
unsigned int msecs;
int i;
msecs = 10000;
msecs = REAL_MODE_TIMEOUT;
for (i=0; i < nr_cpu_ids && msecs > 0; i++) {
if (i == cpu)
continue;
@ -308,22 +300,11 @@ int crash_shutdown_unregister(crash_shutdown_t handler)
}
EXPORT_SYMBOL(crash_shutdown_unregister);
static unsigned long crash_shutdown_buf[JMP_BUF_LEN];
static int crash_shutdown_cpu = -1;
static int handle_fault(struct pt_regs *regs)
{
if (crash_shutdown_cpu == smp_processor_id())
longjmp(crash_shutdown_buf, 1);
return 0;
}
void default_machine_crash_shutdown(struct pt_regs *regs)
{
unsigned int i;
int (*old_handler)(struct pt_regs *regs);
/*
* This function is only called after the system
* has panicked or is otherwise in a critical state.
@ -341,15 +322,26 @@ void default_machine_crash_shutdown(struct pt_regs *regs)
* such that another IPI will not be sent.
*/
crashing_cpu = smp_processor_id();
crash_save_cpu(regs, crashing_cpu);
/*
* If we came in via system reset, wait a while for the secondary
* CPUs to enter.
*/
if (TRAP(regs) == 0x100)
mdelay(PRIMARY_TIMEOUT);
crash_kexec_prepare_cpus(crashing_cpu);
cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
crash_save_cpu(regs, crashing_cpu);
time_to_dump = 1;
crash_kexec_wait_realmode(crashing_cpu);
machine_kexec_mask_interrupts();
/*
* Call registered shutdown routines savely. Swap out
* Call registered shutdown routines safely. Swap out
* __debugger_fault_handler, and replace on exit.
*/
old_handler = __debugger_fault_handler;

175
arch/powerpc/kernel/traps.c
View File

@ -98,18 +98,14 @@ static void pmac_backlight_unblank(void)
static inline void pmac_backlight_unblank(void) { }
#endif
int die(const char *str, struct pt_regs *regs, long err)
static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
static int die_owner = -1;
static unsigned int die_nest_count;
static int die_counter;
static unsigned __kprobes long oops_begin(struct pt_regs *regs)
{
static struct {
raw_spinlock_t lock;
u32 lock_owner;
int lock_owner_depth;
} die = {
.lock = __RAW_SPIN_LOCK_UNLOCKED(die.lock),
.lock_owner = -1,
.lock_owner_depth = 0
};
static int die_counter;
int cpu;
unsigned long flags;
if (debugger(regs))
@ -117,66 +113,109 @@ int die(const char *str, struct pt_regs *regs, long err)
oops_enter();
if (die.lock_owner != raw_smp_processor_id()) {
console_verbose();
raw_spin_lock_irqsave(&die.lock, flags);
die.lock_owner = smp_processor_id();
die.lock_owner_depth = 0;
bust_spinlocks(1);
if (machine_is(powermac))
pmac_backlight_unblank();
} else {
local_save_flags(flags);
}
if (++die.lock_owner_depth < 3) {
printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
#ifdef CONFIG_PREEMPT
printk("PREEMPT ");
#endif
#ifdef CONFIG_SMP
printk("SMP NR_CPUS=%d ", NR_CPUS);
#endif
#ifdef CONFIG_DEBUG_PAGEALLOC
printk("DEBUG_PAGEALLOC ");
#endif
#ifdef CONFIG_NUMA
printk("NUMA ");
#endif
printk("%s\n", ppc_md.name ? ppc_md.name : "");
if (notify_die(DIE_OOPS, str, regs, err, 255,
SIGSEGV) == NOTIFY_STOP)
return 1;
print_modules();
show_regs(regs);
} else {
printk("Recursive die() failure, output suppressed\n");
/* racy, but better than risking deadlock. */
raw_local_irq_save(flags);
cpu = smp_processor_id();
if (!arch_spin_trylock(&die_lock)) {
if (cpu == die_owner)
/* nested oops. should stop eventually */;
else
arch_spin_lock(&die_lock);
}
die_nest_count++;
die_owner = cpu;
console_verbose();
bust_spinlocks(1);
if (machine_is(powermac))
pmac_backlight_unblank();
return flags;
}
static void __kprobes oops_end(unsigned long flags, struct pt_regs *regs,
int signr)
{
bust_spinlocks(0);
die.lock_owner = -1;
die_owner = -1;
add_taint(TAINT_DIE);
raw_spin_unlock_irqrestore(&die.lock, flags);
die_nest_count--;
oops_exit();
printk("\n");
if (!die_nest_count)
/* Nest count reaches zero, release the lock. */
arch_spin_unlock(&die_lock);
raw_local_irq_restore(flags);
if (kexec_should_crash(current) ||
kexec_sr_activated(smp_processor_id()))
/*
* A system reset (0x100) is a request to dump, so we always send
* it through the crashdump code.
*/
if (kexec_should_crash(current) || (TRAP(regs) == 0x100)) {
crash_kexec(regs);
crash_kexec_secondary(regs);
/*
* We aren't the primary crash CPU. We need to send it
* to a holding pattern to avoid it ending up in the panic
* code.
*/
crash_kexec_secondary(regs);
}
if (!signr)
return;
/*
* While our oops output is serialised by a spinlock, output
* from panic() called below can race and corrupt it. If we
* know we are going to panic, delay for 1 second so we have a
* chance to get clean backtraces from all CPUs that are oopsing.
*/
if (in_interrupt() || panic_on_oops || !current->pid ||
is_global_init(current)) {
mdelay(MSEC_PER_SEC);
}
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception");
do_exit(signr);
}
oops_exit();
do_exit(err);
static int __kprobes __die(const char *str, struct pt_regs *regs, long err)
{
printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
#ifdef CONFIG_PREEMPT
printk("PREEMPT ");
#endif
#ifdef CONFIG_SMP
printk("SMP NR_CPUS=%d ", NR_CPUS);
#endif
#ifdef CONFIG_DEBUG_PAGEALLOC
printk("DEBUG_PAGEALLOC ");
#endif
#ifdef CONFIG_NUMA
printk("NUMA ");
#endif
printk("%s\n", ppc_md.name ? ppc_md.name : "");
if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP)
return 1;
print_modules();
show_regs(regs);
return 0;
}
void die(const char *str, struct pt_regs *regs, long err)
{
unsigned long flags = oops_begin(regs);
if (__die(str, regs, err))
err = 0;
oops_end(flags, regs, err);
}
void user_single_step_siginfo(struct task_struct *tsk,
struct pt_regs *regs, siginfo_t *info)
{
@ -195,10 +234,11 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
"at %016lx nip %016lx lr %016lx code %x\n";
if (!user_mode(regs)) {
if (die("Exception in kernel mode", regs, signr))
return;
} else if (show_unhandled_signals &&
unhandled_signal(current, signr)) {
die("Exception in kernel mode", regs, signr);
return;
}
if (show_unhandled_signals && unhandled_signal(current, signr)) {
printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
current->comm, current->pid, signr,
addr, regs->nip, regs->link, code);
@ -220,25 +260,8 @@ void system_reset_exception(struct pt_regs *regs)
return;
}
#ifdef CONFIG_KEXEC
cpumask_set_cpu(smp_processor_id(), &cpus_in_sr);
#endif
die("System Reset", regs, SIGABRT);
/*
* Some CPUs when released from the debugger will execute this path.
* These CPUs entered the debugger via a soft-reset. If the CPU was
* hung before entering the debugger it will return to the hung
* state when exiting this function. This causes a problem in
* kdump since the hung CPU(s) will not respond to the IPI sent
* from kdump. To prevent the problem we call crash_kexec_secondary()
* here. If a kdump had not been initiated or we exit the debugger
* with the "exit and recover" command (x) crash_kexec_secondary()
* will return after 5ms and the CPU returns to its previous state.
*/
crash_kexec_secondary(regs);
/* Must die if the interrupt is not recoverable */
if (!(regs->msr & MSR_RI))
panic("Unrecoverable System Reset");

2
arch/powerpc/platforms/pseries/setup.c
View File

@ -366,6 +366,8 @@ static void pSeries_idle(void)
static void __init pSeries_setup_arch(void)
{
panic_timeout = 10;
/* Discover PIC type and setup ppc_md accordingly */
pseries_discover_pic();

21
arch/powerpc/sysdev/xics/icp-hv.c
View File

@ -41,16 +41,6 @@ static inline unsigned int icp_hv_get_xirr(unsigned char cppr)
return ret;
}
static inline void icp_hv_set_xirr(unsigned int value)
{
long rc = plpar_hcall_norets(H_EOI, value);
if (rc != H_SUCCESS) {
pr_err("%s: bad return code eoi xirr=0x%x returned %ld\n",
__func__, value, rc);
WARN_ON_ONCE(1);
}
}
static inline void icp_hv_set_cppr(u8 value)
{
long rc = plpar_hcall_norets(H_CPPR, value);
@ -61,6 +51,17 @@ static inline void icp_hv_set_cppr(u8 value)
}
}
static inline void icp_hv_set_xirr(unsigned int value)
{
long rc = plpar_hcall_norets(H_EOI, value);
if (rc != H_SUCCESS) {
pr_err("%s: bad return code eoi xirr=0x%x returned %ld\n",
__func__, value, rc);
WARN_ON_ONCE(1);
icp_hv_set_cppr(value >> 24);
}
}
static inline void icp_hv_set_qirr(int n_cpu , u8 value)
{
int hw_cpu = get_hard_smp_processor_id(n_cpu);