Skip to content

Commit

Permalink
x86, nmi: Split out nmi from traps.c
Browse files Browse the repository at this point in the history
The nmi stuff is changing a lot and adding more functionality.  Split it
out from the traps.c file so it doesn't continue to pollute that file.

This makes it easier to find and expand all the future nmi related work.

No real functional changes here.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1317409584-23662-2-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
  • Loading branch information
Don Zickus authored and Ingo Molnar committed Oct 10, 2011
1 parent 144d31e commit 1d48922
Show file tree
Hide file tree
Showing 3 changed files with 179 additions and 156 deletions.
2 changes: 1 addition & 1 deletion arch/x86/kernel/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ endif

obj-y := process_$(BITS).o signal.o entry_$(BITS).o
obj-y += traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o
obj-y += time.o ioport.o ldt.o dumpstack.o
obj-y += time.o ioport.o ldt.o dumpstack.o nmi.o
obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o
obj-$(CONFIG_IRQ_WORK) += irq_work.o
obj-y += probe_roms.o
Expand Down
178 changes: 178 additions & 0 deletions arch/x86/kernel/nmi.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,178 @@
/*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
*
* Pentium III FXSR, SSE support
* Gareth Hughes <gareth@valinux.com>, May 2000
*/

/*
* Handle hardware traps and faults.
*/
#include <linux/spinlock.h>
#include <linux/kprobes.h>
#include <linux/kdebug.h>
#include <linux/nmi.h>

#if defined(CONFIG_EDAC)
#include <linux/edac.h>
#endif

#include <linux/atomic.h>
#include <asm/traps.h>
#include <asm/mach_traps.h>

static int ignore_nmis;

int unknown_nmi_panic;
/*
* Prevent NMI reason port (0x61) being accessed simultaneously, can
* only be used in NMI handler.
*/
static DEFINE_RAW_SPINLOCK(nmi_reason_lock);

static int __init setup_unknown_nmi_panic(char *str)
{
unknown_nmi_panic = 1;
return 1;
}
__setup("unknown_nmi_panic", setup_unknown_nmi_panic);

static notrace __kprobes void
pci_serr_error(unsigned char reason, struct pt_regs *regs)
{
pr_emerg("NMI: PCI system error (SERR) for reason %02x on CPU %d.\n",
reason, smp_processor_id());

/*
* On some machines, PCI SERR line is used to report memory
* errors. EDAC makes use of it.
*/
#if defined(CONFIG_EDAC)
if (edac_handler_set()) {
edac_atomic_assert_error();
return;
}
#endif

if (panic_on_unrecovered_nmi)
panic("NMI: Not continuing");

pr_emerg("Dazed and confused, but trying to continue\n");

/* Clear and disable the PCI SERR error line. */
reason = (reason & NMI_REASON_CLEAR_MASK) | NMI_REASON_CLEAR_SERR;
outb(reason, NMI_REASON_PORT);
}

static notrace __kprobes void
io_check_error(unsigned char reason, struct pt_regs *regs)
{
unsigned long i;

pr_emerg(
"NMI: IOCK error (debug interrupt?) for reason %02x on CPU %d.\n",
reason, smp_processor_id());
show_registers(regs);

if (panic_on_io_nmi)
panic("NMI IOCK error: Not continuing");

/* Re-enable the IOCK line, wait for a few seconds */
reason = (reason & NMI_REASON_CLEAR_MASK) | NMI_REASON_CLEAR_IOCHK;
outb(reason, NMI_REASON_PORT);

i = 20000;
while (--i) {
touch_nmi_watchdog();
udelay(100);
}

reason &= ~NMI_REASON_CLEAR_IOCHK;
outb(reason, NMI_REASON_PORT);
}

static notrace __kprobes void
unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
{
if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) ==
NOTIFY_STOP)
return;
#ifdef CONFIG_MCA
/*
* Might actually be able to figure out what the guilty party
* is:
*/
if (MCA_bus) {
mca_handle_nmi();
return;
}
#endif
pr_emerg("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
reason, smp_processor_id());

pr_emerg("Do you have a strange power saving mode enabled?\n");
if (unknown_nmi_panic || panic_on_unrecovered_nmi)
panic("NMI: Not continuing");

pr_emerg("Dazed and confused, but trying to continue\n");
}

static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
{
unsigned char reason = 0;

/*
* CPU-specific NMI must be processed before non-CPU-specific
* NMI, otherwise we may lose it, because the CPU-specific
* NMI can not be detected/processed on other CPUs.
*/
if (notify_die(DIE_NMI, "nmi", regs, 0, 2, SIGINT) == NOTIFY_STOP)
return;

/* Non-CPU-specific NMI: NMI sources can be processed on any CPU */
raw_spin_lock(&nmi_reason_lock);
reason = get_nmi_reason();

if (reason & NMI_REASON_MASK) {
if (reason & NMI_REASON_SERR)
pci_serr_error(reason, regs);
else if (reason & NMI_REASON_IOCHK)
io_check_error(reason, regs);
#ifdef CONFIG_X86_32
/*
* Reassert NMI in case it became active
* meanwhile as it's edge-triggered:
*/
reassert_nmi();
#endif
raw_spin_unlock(&nmi_reason_lock);
return;
}
raw_spin_unlock(&nmi_reason_lock);

unknown_nmi_error(reason, regs);
}

dotraplinkage notrace __kprobes void
do_nmi(struct pt_regs *regs, long error_code)
{
nmi_enter();

inc_irq_stat(__nmi_count);

if (!ignore_nmis)
default_do_nmi(regs);

nmi_exit();
}

void stop_nmi(void)
{
ignore_nmis++;
}

void restart_nmi(void)
{
ignore_nmis--;
}
155 changes: 0 additions & 155 deletions arch/x86/kernel/traps.c
Original file line number Diff line number Diff line change
Expand Up @@ -81,15 +81,6 @@ gate_desc idt_table[NR_VECTORS] __page_aligned_data = { { { { 0, 0 } } }, };
DECLARE_BITMAP(used_vectors, NR_VECTORS);
EXPORT_SYMBOL_GPL(used_vectors);

static int ignore_nmis;

int unknown_nmi_panic;
/*
* Prevent NMI reason port (0x61) being accessed simultaneously, can
* only be used in NMI handler.
*/
static DEFINE_RAW_SPINLOCK(nmi_reason_lock);

static inline void conditional_sti(struct pt_regs *regs)
{
if (regs->flags & X86_EFLAGS_IF)
Expand Down Expand Up @@ -307,152 +298,6 @@ do_general_protection(struct pt_regs *regs, long error_code)
die("general protection fault", regs, error_code);
}

static int __init setup_unknown_nmi_panic(char *str)
{
unknown_nmi_panic = 1;
return 1;
}
__setup("unknown_nmi_panic", setup_unknown_nmi_panic);

static notrace __kprobes void
pci_serr_error(unsigned char reason, struct pt_regs *regs)
{
pr_emerg("NMI: PCI system error (SERR) for reason %02x on CPU %d.\n",
reason, smp_processor_id());

/*
* On some machines, PCI SERR line is used to report memory
* errors. EDAC makes use of it.
*/
#if defined(CONFIG_EDAC)
if (edac_handler_set()) {
edac_atomic_assert_error();
return;
}
#endif

if (panic_on_unrecovered_nmi)
panic("NMI: Not continuing");

pr_emerg("Dazed and confused, but trying to continue\n");

/* Clear and disable the PCI SERR error line. */
reason = (reason & NMI_REASON_CLEAR_MASK) | NMI_REASON_CLEAR_SERR;
outb(reason, NMI_REASON_PORT);
}

static notrace __kprobes void
io_check_error(unsigned char reason, struct pt_regs *regs)
{
unsigned long i;

pr_emerg(
"NMI: IOCK error (debug interrupt?) for reason %02x on CPU %d.\n",
reason, smp_processor_id());
show_registers(regs);

if (panic_on_io_nmi)
panic("NMI IOCK error: Not continuing");

/* Re-enable the IOCK line, wait for a few seconds */
reason = (reason & NMI_REASON_CLEAR_MASK) | NMI_REASON_CLEAR_IOCHK;
outb(reason, NMI_REASON_PORT);

i = 20000;
while (--i) {
touch_nmi_watchdog();
udelay(100);
}

reason &= ~NMI_REASON_CLEAR_IOCHK;
outb(reason, NMI_REASON_PORT);
}

static notrace __kprobes void
unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
{
if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) ==
NOTIFY_STOP)
return;
#ifdef CONFIG_MCA
/*
* Might actually be able to figure out what the guilty party
* is:
*/
if (MCA_bus) {
mca_handle_nmi();
return;
}
#endif
pr_emerg("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
reason, smp_processor_id());

pr_emerg("Do you have a strange power saving mode enabled?\n");
if (unknown_nmi_panic || panic_on_unrecovered_nmi)
panic("NMI: Not continuing");

pr_emerg("Dazed and confused, but trying to continue\n");
}

static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
{
unsigned char reason = 0;

/*
* CPU-specific NMI must be processed before non-CPU-specific
* NMI, otherwise we may lose it, because the CPU-specific
* NMI can not be detected/processed on other CPUs.
*/
if (notify_die(DIE_NMI, "nmi", regs, 0, 2, SIGINT) == NOTIFY_STOP)
return;

/* Non-CPU-specific NMI: NMI sources can be processed on any CPU */
raw_spin_lock(&nmi_reason_lock);
reason = get_nmi_reason();

if (reason & NMI_REASON_MASK) {
if (reason & NMI_REASON_SERR)
pci_serr_error(reason, regs);
else if (reason & NMI_REASON_IOCHK)
io_check_error(reason, regs);
#ifdef CONFIG_X86_32
/*
* Reassert NMI in case it became active
* meanwhile as it's edge-triggered:
*/
reassert_nmi();
#endif
raw_spin_unlock(&nmi_reason_lock);
return;
}
raw_spin_unlock(&nmi_reason_lock);

unknown_nmi_error(reason, regs);
}

dotraplinkage notrace __kprobes void
do_nmi(struct pt_regs *regs, long error_code)
{
nmi_enter();

inc_irq_stat(__nmi_count);

if (!ignore_nmis)
default_do_nmi(regs);

nmi_exit();
}

void stop_nmi(void)
{
ignore_nmis++;
}

void restart_nmi(void)
{
ignore_nmis--;
}

/* May run on IST stack. */
dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
{
Expand Down

0 comments on commit 1d48922

Please sign in to comment.