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path: root/arch/sparc/kernel/nmi.c
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2014-08-26sparc: Replace __get_cpu_var usesChristoph Lameter
__get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : #define __get_cpu_var(var) (*this_cpu_ptr(&(var))) __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: sparclinux@vger.kernel.org Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-11sparc64: Do not disable interrupts in nmi_cpu_busy()David S. Miller
nmi_cpu_busy() is a SMP function call that just makes sure that all of the cpus are spinning using cpu cycles while the NMI test runs. It does not need to disable IRQs because we just care about NMIs executing which will even with 'normal' IRQs disabled. It is not legal to enable hard IRQs in a SMP cross call, in fact this bug triggers the BUG check in irq_work_run_list(): BUG_ON(!irqs_disabled()); Because now irq_work_run() is invoked from the tail of generic_smp_call_function_single_interrupt(). Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-03sparc64: Normalize NMI watchdog logging and behavior.David S. Miller
Bring this code in line with the perf based generic NMI watchdog in kernel/watchdog.c (which we should convert over to at some point). In particular, don't do anything super fancy when the watchdog triggers, and specifically don't do a do_exit() which only makes things worse. Either panic(), or WARN(). The latter of which will do all of the actions such as give us a stack backtrace. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-18sparc64: Abstract away the %pcr values used to enable/disable NMIDavid S. Miller
We assumed PCR_PIC_PRIV can always be used to disable it, but that won't be true for SPARC-T4. This allows us also to get rid of some messy defines used in only one location. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-18sparc64: Abstract away the NMI PIC counter computation.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-18sparc64: Abstract away PIC register accesses.David S. Miller
And, like for the PCR, allow indexing of different PIC register numbers. This also removes all of the non-__KERNEL__ bits from asm/perfctr.h, nothing kernel side should include it any more. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-18sparc64: Add 'reg_num' argument to pcr_ops methods.David S. Miller
SPARC-T4 and later have multiple PCR registers, one for each PIC counter. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-28Disintegrate asm/system.h for SparcDavid Howells
Disintegrate asm/system.h for Sparc. Signed-off-by: David Howells <dhowells@redhat.com> cc: sparclinux@vger.kernel.org
2011-10-31sparc: move symbol exporters to use export.h not module.hPaul Gortmaker
Many of the core sparc kernel files are not modules, but just including module.h for exporting symbols. Now these files can use the lighter footprint export.h for this role. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2010-11-26perf, arch: Cleanup perf-pmu init vs lockup-detectorPeter Zijlstra
The perf hardware pmu got initialized at various points in the boot, some before early_initcall() some after (notably arch_initcall). The problem is that the NMI lockup detector is ran from early_initcall() and expects the hardware pmu to be present. Sanitize this by moving all architecture hardware pmu implementations to initialize at early_initcall() and move the lockup detector to an explicit initcall right after that. Cc: paulus <paulus@samba.org> Cc: davem <davem@davemloft.net> Cc: Michael Cree <mcree@orcon.net.nz> Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1290707759.2145.119.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-14sparc64: Run NMIs on the hardirq stack.David S. Miller
Otherwise we can overflow the main stack with the function tracer enabled. Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-12sparc64: Use a seperate counter for timer interrupts and NMI checks, like x86.David S. Miller
This keeps us from having to use kstat_irqs_cpu() from the NMI handler, the former of which is a profiled function. Instead we use a currently empty slot in the cpu_data Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-02Merge branch 'master' into percpuTejun Heo
2010-01-05local_t: Remove leftover local.hChristoph Lameter
Somehow the local.h was not removed when taking out the local_t usage during the 2.6.32 merge. CC: David Miller <davem@davemloft.net> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-01-04sparc64: Fix NMI programming when perf events are active.David S. Miller
If perf events are active, we should not reset the %pcr to PCR_PIC_PRIV. That perf events code does the management. Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-29percpu: remove per_cpu__ prefix.Rusty Russell
Now that the return from alloc_percpu is compatible with the address of per-cpu vars, it makes sense to hand around the address of per-cpu variables. To make this sane, we remove the per_cpu__ prefix we used created to stop people accidentally using these vars directly. Now we have sparse, we can use that (next patch). tj: * Updated to convert stuff which were missed by or added after the original patch. * Kill per_cpu_var() macro. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
2009-10-12this_cpu: Use this_cpu_xx in nmi handlingChristoph Lameter
this_cpu_inc/dec reduces the number of instructions needed. Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-09-21perf: Do the big rename: Performance Counters -> Performance EventsIngo Molnar
Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\<event\>/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-11Merge branch 'master' of /home/davem/src/GIT/linux-2.6/David S. Miller
Conflicts: arch/sparc/Kconfig
2009-09-10sparc64: Initial hw perf counter support.David S. Miller
Only supports one simple counter and only UltraSPARC-IIIi chips. Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-10sparc64: Use nmi_enter() and nmi_exit(), as needed.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-08sparc64: Make touch_nmi_watchdog() actually work.David S. Miller
It guards it's actions on nmi_watchdog_active, but nothing ever sets that and it's initial value is zero. Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-08sparc64: Manage NMI watchdog enabling like x86.David S. Miller
Use a per-cpu 'wd_enabled' boolean and a global atomic_t count of watchdog NMI enabled cpus which is set to '-1' if something is wrong with the watchdog and it can't be used. Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-03sparc64: Kill spurious NMI watchdog triggers by increasing limit to 30 seconds.David S. Miller
This is a compromise and a temporary workaround for bootup NMI watchdog triggers some people see with qla2xxx devices present. This happens when, for example: CPU 0 is in the driver init and looping submitting mailbox commands to load the firmware, then waiting for completion. CPU 1 is receiving the device interrupts. CPU 1 is where the NMI watchdog triggers. CPU 0 is submitting mailbox commands fast enough that by the time CPU 1 returns from the device interrupt handler, a new one is pending. This sequence runs for more than 5 seconds. The problematic case is CPU 1's timer interrupt running when the barrage of device interrupts begin. Then we have: timer interrupt return for softirq checking pending, thus enable interrupts qla2xxx interrupt return qla2xxx interrupt return ... 5+ seconds pass final qla2xxx interrupt for fw load return run timer softirq return At some point in the multi-second qla2xxx interrupt storm we trigger the NMI watchdog on CPU 1 from the NMI interrupt handler. The timer softirq, once we get back to running it, is smart enough to run the timer work enough times to make up for the missed timer interrupts. However, the NMI watchdogs (both x86 and sparc) use the timer interrupt count to notice the cpu is wedged. But in the above scenerio we'll receive only one such timer interrupt even if we last all the way back to running the timer softirq. The default watchdog trigger point is only 5 seconds, which is pretty low (the softwatchdog triggers at 60 seconds). So increase it to 30 seconds for now. Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-29sparc64: Fix reset hangs on Niagara systems.David S. Miller
Hypervisor versions older than version 1.6.1 cannot handle leaving the profile counter overflow interrupt chirping when the system does a soft reset. So use a reboot notifier to shut off the NMI watchdog. Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-04sparc64: Call dump_stack() in die_nmi().David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-02sparc: fixup for sparseirq changesStephen Rothwell
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-30sparc64: Implement NMI watchdog on capable cpus.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>