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* x86: Save cr2 in NMI in case NMIs take a page fault (for i386)Steven Rostedt2012-06-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avi Kivity reported that page faults in NMIs could cause havic if the NMI preempted another page fault handler: The recent changes to NMI allow exceptions to take place in NMI handlers, but I think that a #PF (say, due to access to vmalloc space) is still problematic. Consider the sequence #PF (cr2 set by processor) NMI ... #PF (cr2 clobbered) do_page_fault() IRET ... IRET do_page_fault() address = read_cr2() The last line reads the overwritten cr2 value. This is the i386 version, which has the luxury of doing the work in C code. Link: http://lkml.kernel.org/r/4FBB8C40.6080304@redhat.com Reported-by: Avi Kivity <avi@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* x86: Remove cmpxchg from i386 NMI nesting codeSteven Rostedt2012-06-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I've been informed by someone on LWN called 'slashdot' that some i386 machines do not support a true cmpxchg. The cmpxchg used by the i386 NMI nesting code must be a true cmpxchg as disabling interrupts will not work for NMIs (which is the work around for i386s that do not have a true cmpxchg). This 'slashdot' character also suggested a fix to the issue. As the state of the nesting NMIs goes as follows: NOT_RUNNING -> EXECUTING EXECUTING -> NOT_RUNNING EXECUTING -> LATCHED LATCHED -> EXECUTING Having these states as enum values of: NOT_RUNNING = 0 EXECUTING = 1 LATCHED = 2 Instead of a cmpxchg to make EXECUTING -> NOT_RUNNING a dec_and_test() would work as well. If the dec_and_test brings the state to NOT_RUNNING, that is the same as a cmpxchg succeeding to change EXECUTING to NOT_RUNNING. If a nested NMI were to come in and change it to LATCHED, the dec_and_test() would convert the state to EXECUTING (what we want it to be in such a case anyway). I asked 'slashdot' to post this as a patch, but it never came to be. I decided to do the work instead. Thanks to H. Peter Anvin for suggesting to use this_cpu_dec_and_return() instead of local_dec_and_test(&__get_cpu_var()). Link: http://lwn.net/Articles/484932/ Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* x86: Reset the debug_stack update counterSteven Rostedt2012-05-31
| | | | | | | | | | | | | | | When an NMI goes off and it sees that it preempted the debug stack, to keep the debug stack safe, it changes the IDT to point to one that does not modify the stack on breakpoint (to allow breakpoints in NMIs). But the variable that gets set to know to undo it on exit never gets cleared on exit. Thus every NMI will reset it on exit the first time it is done even if it does not need to be reset. [ Added H. Peter Anvin's suggestion to use this_cpu_read/write ] Cc: <stable@vger.kernel.org> # v3.3 Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge branch 'delete-mca' of ↵Linus Torvalds2012-05-23
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull the MCA deletion branch from Paul Gortmaker: "It was good that we could support MCA machines back in the day, but realistically, nobody is using them anymore. They were mostly limited to 386-sx 16MHz CPU and some 486 class machines and never more than 64MB of RAM. Even the enthusiast hobbyist community seems to have dried up close to ten years ago, based on what you can find searching various websites dedicated to the relatively short lived hardware. So lets remove the support relating to CONFIG_MCA. There is no point carrying this forward, wasting cycles doing routine maintenance on it; wasting allyesconfig build time on validating it, wasting I/O on git grep'ping over it, and so on." Let's see if anybody screams. It generally has compiled, and James Bottomley pointed out that there was a MCA extension from NCR that allowed for up to 4GB of memory and PPro-class machines. So in *theory* there may be users out there. But even James (technically listed as a maintainer) doesn't actually have a system, and while Alan Cox claims to have a machine in his cellar that he offered to anybody who wants to take it off his hands, he didn't argue for keeping MCA support either. So we could bring it back. But somebody had better speak up and talk about how they have actually been using said MCA hardware with modern kernels for us to do that. And David already took the patch to delete all the networking driver code (commit a5e371f61ad3: "drivers/net: delete all code/drivers depending on CONFIG_MCA"). * 'delete-mca' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: MCA: delete all remaining traces of microchannel bus support. scsi: delete the MCA specific drivers and driver code serial: delete the MCA specific 8250 support. arm: remove ability to select CONFIG_MCA
| * MCA: delete all remaining traces of microchannel bus support.Paul Gortmaker2012-05-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hardware with MCA bus is limited to 386 and 486 class machines that are now 20+ years old and typically with less than 32MB of memory. A quick search on the internet, and you see that even the MCA hobbyist/enthusiast community has lost interest in the early 2000 era and never really even moved ahead from the 2.4 kernels to the 2.6 series. This deletes anything remaining related to CONFIG_MCA from core kernel code and from the x86 architecture. There is no point in carrying this any further into the future. One complication to watch for is inadvertently scooping up stuff relating to machine check, since there is overlap in the TLA name space (e.g. arch/x86/boot/mca.c). Cc: Thomas Gleixner <tglx@linutronix.de> Cc: James Bottomley <JBottomley@Parallels.com> Cc: x86@kernel.org Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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*-. \ Merge branches 'x86-asm-for-linus', 'x86-cleanups-for-linus', ↵Linus Torvalds2012-05-23
|\ \ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'x86-cpu-for-linus', 'x86-debug-for-linus' and 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull initial trivial x86 stuff from Ingo Molnar. Various random cleanups and trivial fixes. * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86-64: Eliminate dead ia32 syscall handlers * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/pci-calgary_64.c: Remove obsoleted simple_strtoul() usage x86: Don't continue booting if we can't load the specified initrd x86: kernel/dumpstack.c simple_strtoul cleanup x86: kernel/check.c simple_strtoul cleanup debug: Add CONFIG_READABLE_ASM x86: spinlock.h: Remove REG_PTR_MODE * 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cache_info: Fix setup of l2/l3 ids * 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Avoid double stack traces with show_regs() * 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, microcode: microcode_core.c simple_strtoul cleanup
| | * x86: Avoid double stack traces with show_regs()Jan Beulich2012-05-09
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | What was called show_registers() so far already showed a stack trace for kernel faults, and kernel_stack_pointer() isn't even valid to be used for faults from user mode, hence it was pointless for show_regs() to call show_trace() after show_registers(). Simply rename show_registers() to show_regs() and eliminate the old definition. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/4FAA3D3902000078000826E1@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2012-05-22
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf changes from Ingo Molnar: "Lots of changes: - (much) improved assembly annotation support in perf report, with jump visualization, searching, navigation, visual output improvements and more. - kernel support for AMD IBS PMU hardware features. Notably 'perf record -e cycles:p' and 'perf top -e cycles:p' should work without skid now, like PEBS does on the Intel side, because it takes advantage of IBS transparently. - the libtracevents library: it is the first step towards unifying tracing tooling and perf, and it also gives a tracing library for external tools like powertop to rely on. - infrastructure: various improvements and refactoring of the UI modules and related code - infrastructure: cleanup and simplification of the profiling targets code (--uid, --pid, --tid, --cpu, --all-cpus, etc.) - tons of robustness fixes all around - various ftrace updates: speedups, cleanups, robustness improvements. - typing 'make' in tools/ will now give you a menu of projects to build and a short help text to explain what each does. - ... and lots of other changes I forgot to list. The perf record make bzImage + perf report regression you reported should be fixed." * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (166 commits) tracing: Remove kernel_lock annotations tracing: Fix initial buffer_size_kb state ring-buffer: Merge separate resize loops perf evsel: Create events initially disabled -- again perf tools: Split term type into value type and term type perf hists: Fix callchain ip printf format perf target: Add uses_mmap field ftrace: Remove selecting FRAME_POINTER with FUNCTION_TRACER ftrace/x86: Have x86 ftrace use the ftrace_modify_all_code() ftrace: Make ftrace_modify_all_code() global for archs to use ftrace: Return record ip addr for ftrace_location() ftrace: Consolidate ftrace_location() and ftrace_text_reserved() ftrace: Speed up search by skipping pages by address ftrace: Remove extra helper functions ftrace: Sort all function addresses, not just per page tracing: change CPU ring buffer state from tracing_cpumask tracing: Check return value of tracing_dentry_percpu() ring-buffer: Reset head page before running self test ring-buffer: Add integrity check at end of iter read ring-buffer: Make addition of pages in ring buffer atomic ...
| * | ftrace/x86: Remove the complex ftrace NMI handling codeSteven Rostedt2012-04-27
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As ftrace function tracing would require modifying code that could be executed in NMI context, which is not stopped with stop_machine(), ftrace had to do a complex algorithm with various stages of setup and memory barriers to make it work. With the new breakpoint method, this is no longer required. The changes to the code can be done without any problem in NMI context, as well as without stop machine altogether. Remove the complex code as it is no longer needed. Also, a lot of the notrace annotations could be removed from the NMI code as it is now safe to trace them. With the exception of do_nmi itself, which does some special work to handle running in the debug stack. The breakpoint method can cause NMIs to double nest the debug stack if it's not setup properly, and that is done in do_nmi(), thus that function must not be traced. (Note the arch sh may want to do the same) Cc: Paul Mundt <lethal@linux-sh.org> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | x86/nmi: Fix page faults by nmiaction if kmemcheck is enabledLi Zhong2012-04-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch tries to fix the problem of page fault exception caused by accessing nmiaction structure in nmi if kmemcheck is enabled. If kmemcheck is enabled, the memory allocated through slab are in pages that are marked non-present, so that some checks could be done in the page fault handling code ( e.g. whether the memory is read before written to ). As nmiaction is allocated in this way, so it resides in a non-present page. Then there is a page fault while the nmi code accessing the nmiaction structure, which would then cause a warning by WARN_ON_ONCE(in_nmi()) in kmemcheck_fault(), called by do_page_fault(). This significantly simplifies the code as well, as the whole dynamic allocation dance goes away. v2: as Peter suggested, changed the nmiaction to use static storage. v3: as Peter suggested, use macro to shorten the codes. Also keep the original usage of register_nmi_handler, so users of this call doesn't need change. Tested-by: Seiji Aguchi <seiji.aguchi@hds.com> Fixes: https://lkml.org/lkml/2012/3/2/356 Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> [ simplified the wrappers ] Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: thomas.mingarelli@hp.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1333051877-15755-4-git-send-email-dzickus@redhat.com [ tidied the patch a bit ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | x86/nmi: Add new NMI queues to deal with IO_CHK and SERRDon Zickus2012-04-25
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | In discussions with Thomas Mingarelli about hpwdt, he explained to me some issues they were some when using their virtual NMI button to test the hpwdt driver. It turns out the virtual NMI button used on HP's machines do no send unknown NMIs but instead send IO_CHK NMIs. The way the kernel code is written, the hpwdt driver can not register itself against that type of NMI and therefore can not successfully capture system information before panic'ing. To solve this I created two new NMI queues to allow driver to register against the IO_CHK and SERR NMIs. Or in the hpwdt all three (if you include unknown NMIs too). The change is straightforward and just mimics what the unknown NMI does. Reported-and-tested-by: Thomas Mingarelli <thomas.mingarelli@hp.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1333051877-15755-3-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86: Allow NMIs to hit breakpoints in i386Steven Rostedt2011-12-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With i386, NMIs and breakpoints use the current stack and they do not reset the stack pointer to a fix point that might corrupt a previous NMI or breakpoint (as it does in x86_64). But NMIs are still not made to be re-entrant, and need to prevent the case that an NMI hitting a breakpoint (which does an iret), doesn't allow another NMI to run. The fix is to let the NMI be in 3 different states: 1) not running 2) executing 3) latched When no NMI is executing on a given CPU, the state is "not running". When the first NMI comes in, the state is switched to "executing". On exit of that NMI, a cmpxchg is performed to switch the state back to "not running" and if that fails, the NMI is restarted. If a breakpoint is hit and does an iret, which re-enables NMIs, and another NMI comes in before the first NMI finished, it will detect that the state is not in the "not running" state and the current NMI is nested. In this case, the state is switched to "latched" to let the interrupted NMI know to restart the NMI handler, and the nested NMI exits without doing anything. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Paul Turner <pjt@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* x86: Keep current stack in NMI breakpointsSteven Rostedt2011-12-21
| | | | | | | | | | | | | | | | | | | | | | We want to allow NMI handlers to have breakpoints to be able to remove stop_machine from ftrace, kprobes and jump_labels. But if an NMI interrupts a current breakpoint, and then it triggers a breakpoint itself, it will switch to the breakpoint stack and corrupt the data on it for the breakpoint processing that it interrupted. Instead, have the NMI check if it interrupted breakpoint processing by checking if the stack that is currently used is a breakpoint stack. If it is, then load a special IDT that changes the IST for the debug exception to keep the same stack in kernel context. When the NMI is done, it puts it back. This way, if the NMI does trigger a breakpoint, it will keep using the same stack and not stomp on the breakpoint data for the breakpoint it interrupted. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* x86, ioapic: Only print ioapic debug information for IRQs belonging to an ↵Mathias Nyman2011-11-10
| | | | | | | | | | | | | | | | | | ioapic chip with "apic=verbose" the print_IO_APIC() function tries to print IRQ to pin mappings for every active irq. It assumes chip_data is of type irq_cfg and may cause an oops if not. As the print_IO_APIC() is called from a late_initcall other chained irq chips may already be registered with custom chip_data information, causing an oops. This is the case with intel MID SoC devices with gpio demuxers registered as irq_chips. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> [ -v2: fixed build failure ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86/mrst: Avoid reporting wrong nmi statusJacob Pan2011-11-10
| | | | | | | | | | | | | | | | | | | | Moorestown/Medfield platform does not have port 0x61 to report NMI status, nor does it have external NMI sources. The only NMI sources are from lapic, as results of perf counter overflow or IPI, e.g. NMI watchdog or spin lock debug. Reading port 0x61 on Moorestown will return 0xff which misled NMI handlers to false critical errors such memory parity error. The subsequent ioport access for NMI handling can also cause undefined behavior on Moorestown. This patch allows kernel process NMI due to watchdog or backrace dump without unnecessary hangs. Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> [hand applied] Signed-off-by: Alan Cox <alan@linux.intel.com>
* x86: Fix files explicitly requiring export.h for EXPORT_SYMBOL/THIS_MODULEPaul Gortmaker2011-10-31
| | | | | | | | | | | | | | | | These files were implicitly getting EXPORT_SYMBOL via device.h which was including module.h, but that will be fixed up shortly. By fixing these now, we can avoid seeing things like: arch/x86/kernel/rtc.c:29: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’ arch/x86/kernel/pci-dma.c:20: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’ arch/x86/kernel/e820.c:69: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL_GPL’ [ with input from Randy Dunlap <rdunlap@xenotime.net> and also from Stephen Rothwell <sfr@canb.auug.org.au> ] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* x86, nmi, drivers: Fix nmi splitup build bugIngo Molnar2011-10-10
| | | | | | | | | | | | | | nmi.c needs an #include <linux/mca.h>: arch/x86/kernel/nmi.c: In function ‘unknown_nmi_error’: arch/x86/kernel/nmi.c:286:6: error: ‘MCA_bus’ undeclared (first use in this function) arch/x86/kernel/nmi.c:286:6: note: each undeclared identifier is reported only once for each function it appears in Another one is the hpwdt driver: drivers/watchdog/hpwdt.c:507:9: error: ‘NMI_DONE’ undeclared (first use in this function) Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, nmi: Track NMI usage statsDon Zickus2011-10-10
| | | | | | | | | | | Now that the NMI handler are broken into lists, increment the appropriate stats for each list. This allows us to see what is going on when they get printed out in the next patch. Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1317409584-23662-6-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, nmi: Add in logic to handle multiple events and unknown NMIsDon Zickus2011-10-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previous patches allow the NMI subsystem to process multipe NMI events in one NMI. As previously discussed this can cause issues when an event triggered another NMI but is processed in the current NMI. This causes the next NMI to go unprocessed and become an 'unknown' NMI. To handle this, we first have to flag whether or not the NMI handler handled more than one event or not. If it did, then there exists a chance that the next NMI might be already processed. Once the NMI is flagged as a candidate to be swallowed, we next look for a back-to-back NMI condition. This is determined by looking at the %rip from pt_regs. If it is the same as the previous NMI, it is assumed the cpu did not have a chance to jump back into a non-NMI context and execute code and instead handled another NMI. If both of those conditions are true then we will swallow any unknown NMI. There still exists a chance that we accidentally swallow a real unknown NMI, but for now things seem better. An optimization has also been added to the nmi notifier rountine. Because x86 can latch up to one NMI while currently processing an NMI, we don't have to worry about executing _all_ the handlers in a standalone NMI. The idea is if multiple NMIs come in, the second NMI will represent them. For those back-to-back NMI cases, we have the potentail to drop NMIs. Therefore only execute all the handlers in the second half of a detected back-to-back NMI. Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1317409584-23662-5-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, nmi: Wire up NMI handlers to new routinesDon Zickus2011-10-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just convert all the files that have an nmi handler to the new routines. Most of it is straight forward conversion. A couple of places needed some tweaking like kgdb which separates the debug notifier from the nmi handler and mce removes a call to notify_die. [Thanks to Ying for finding out the history behind that mce call https://lkml.org/lkml/2010/5/27/114 And Boris responding that he would like to remove that call because of it https://lkml.org/lkml/2011/9/21/163] The things that get converted are the registeration/unregistration routines and the nmi handler itself has its args changed along with code removal to check which list it is on (most are on one NMI list except for kgdb which has both an NMI routine and an NMI Unknown routine). Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Corey Minyard <minyard@acm.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Robert Richter <robert.richter@amd.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Corey Minyard <minyard@acm.org> Cc: Jack Steiner <steiner@sgi.com> Link: http://lkml.kernel.org/r/1317409584-23662-4-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, nmi: Create new NMI handler routinesDon Zickus2011-10-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The NMI handlers used to rely on the notifier infrastructure. This worked great until we wanted to support handling multiple events better. One of the key ideas to the nmi handling is to process _all_ the handlers for each NMI. The reason behind this switch is because NMIs are edge triggered. If enough NMIs are triggered, then they could be lost because the cpu can only latch at most one NMI (besides the one currently being processed). In order to deal with this we have decided to process all the NMI handlers for each NMI. This allows the handlers to determine if they recieved an event or not (the ones that can not determine this will be left to fend for themselves on the unknown NMI list). As a result of this change it is now possible to have an extra NMI that was destined to be received for an already processed event. Because the event was processed in the previous NMI, this NMI gets dropped and becomes an 'unknown' NMI. This of course will cause printks that scare people. However, we prefer to have extra NMIs as opposed to losing NMIs and as such are have developed a basic mechanism to catch most of them. That will be a later patch. To accomplish this idea, I unhooked the nmi handlers from the notifier routines and created a new mechanism loosely based on doIRQ. The reason for this is the notifier routines have a couple of shortcomings. One we could't guarantee all future NMI handlers used NOTIFY_OK instead of NOTIFY_STOP. Second, we couldn't keep track of the number of events being handled in each routine (most only handle one, perf can handle more than one). Third, I wanted to eventually display which nmi handlers are registered in the system in /proc/interrupts to help see who is generating NMIs. The patch below just implements the new infrastructure but doesn't wire it up yet (that is the next patch). Its design is based on doIRQ structs and the atomic notifier routines. So the rcu stuff in the patch isn't entirely untested (as the notifier routines have soaked it) but it should be double checked in case I copied the code wrong. Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1317409584-23662-3-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, nmi: Split out nmi from traps.cDon Zickus2011-10-10
| | | | | | | | | | | | | | 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>
* x86, apic: move APIC drivers to arch/x86/kernel/apic/*Ingo Molnar2009-02-17
| | | | | | | | | | | | | arch/x86/kernel/ is getting a bit crowded, and the APIC drivers are scattered into various different files. Move them to arch/x86/kernel/apic/*, and also remove the 'gen' prefix from those which had it. Also move APIC related functionality: the IO-APIC driver, the NMI and the IPI code. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, apic: remove genapic.hIngo Molnar2009-02-17
| | | | | | | | Impact: cleanup Remove genapic.h and remove all references to it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: fold apic_ops into genapicYinghai Lu2009-02-17
| | | | | | | | | | | | Impact: cleanup make it simpler, don't need have one extra struct. v2: fix the sgi_uv build Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: move mach-default/*.h files to asm/Ingo Molnar2009-01-29
| | | | | | | | We are getting rid of subarchitecture support - move the hook files to asm/. (These are now stale and should be replaced with more explicit runtime mechanisms - but the transition is simpler this way.) Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86-64: Move irq stats from PDA to per-cpu and consolidate with 32-bit.Brian Gerst2009-01-18
| | | | | Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* x86: remove duplicated #include'sHuang Weiyi2009-01-06
| | | | | | | | | | Removed duplicated #include's in: arch/x86/kernel/mpparse.c arch/x86/kernel/nmi.c Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: nmi.c fix style problemsJaswinder Singh Rajput2009-01-02
| | | | | | | | | | | | | | Impact: cleanup, fix style problems Fixes style problems: WARNING: Use #include <linux/smp.h> instead of <asm/smp.h> WARNING: Use #include <linux/nmi.h> instead of <asm/nmi.h> total: 0 errors, 2 warnings Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
*-. Merge branches 'x86/apic', 'x86/cleanups', 'x86/cpufeature', ↵Ingo Molnar2008-12-23
|\ \ | | | | | | | | | 'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/detect-hyper', 'x86/doc', 'x86/dumpstack', 'x86/early-printk', 'x86/fpu', 'x86/idle', 'x86/io', 'x86/memory-corruption-check', 'x86/microcode', 'x86/mm', 'x86/mtrr', 'x86/nmi-watchdog', 'x86/pat2', 'x86/pci-ioapic-boot-irq-quirks', 'x86/ptrace', 'x86/quirks', 'x86/reboot', 'x86/setup-memory', 'x86/signal', 'x86/sparse-fixes', 'x86/time', 'x86/uv' and 'x86/xen' into x86/core
| | * x86: nmi - add sensible names to nmi_watchdog boot paramCyrill Gorcunov2008-10-30
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | Impact: introduce nmi_watchdog=lapic and nmi_watchdog=ioapic aliases Add sensible names as "lapic" and "ioapic" to nmi_watchdog boot parameter. Sometimes it is not that easy to recall what exactly nmi_watchdog=1 does mean so we allow the using of symbolic names here. Old numeric values remain valid. Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * x86, NMI watchdog: disable NMIs on LVT0 in case NMI watchdog is not workingAristeu Rozanski2008-10-27
| | | | | | | | | | | | | | | | | | | | | | | | Impact: change NMI watchdog detection and disabling sequence Currently, if the NMI watchdog fails using IOAPIC method, it'll only disable interrupts on 8259 if the timer is passing thru it. This patch disables NMI delivery on LINT0 if the NMI watchdog initial test fails, just for safety. Signed-off-by: Aristeu Rozanski <aris@redhat.com> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * x86, NMI watchdog: add support to enable and disable IOAPIC NMIAristeu Rozanski2008-10-27
|/ | | | | | | | | | | Impact: change/improve the way /proc/sys/kernel/nmi_watchdog works This patch adds support to enable/disable IOAPIC NMI watchdog in runtime via procfs. Signed-off-by: Aristeu Rozanski <aris@redhat.com> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, NMI watchdog: setup before enabling NMI watchdogAristeu Rozanski2008-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a small window when NMI watchdog is being set up that if any NMIs are triggered, the NMI code will make make use of not initalized wd_ops elements: void setup_apic_nmi_watchdog(void *unused) { if (__get_cpu_var(wd_enabled)) return; /* cheap hack to support suspend/resume */ /* if cpu0 is not active neither should the other cpus */ if (smp_processor_id() != 0 && atomic_read(&nmi_active) <= 0) return; switch (nmi_watchdog) { case NMI_LOCAL_APIC: /* enable it before to avoid race with handler */ --> __get_cpu_var(wd_enabled) = 1; --> if (lapic_watchdog_init(nmi_hz) < 0) { (...) asmlinkage notrace __kprobes void default_do_nmi(struct pt_regs *regs) { (...) if (nmi_watchdog_tick(regs, reason)) return; (...) notrace __kprobes int nmi_watchdog_tick(struct pt_regs *regs, unsigned reason) { (...) if (!__get_cpu_var(wd_enabled)) return rc; switch (nmi_watchdog) { case NMI_LOCAL_APIC: rc |= lapic_wd_event(nmi_hz); (...) int lapic_wd_event(unsigned nmi_hz) { struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); u64 ctr; --> rdmsrl(wd->perfctr_msr, ctr); and wd->*_msr will be initialized on each processor type specific setup, after enabling NMIs for PMIs. Since the counter was just set, the chances of an performance counter generated NMI is minimal, but any other unknown NMI would trigger the problem. This patch fixes the problem by setting everything up before enabling performance counter generated NMIs and will set wd_enabled using a callback function. Signed-off-by: Aristeu Rozanski <aris@redhat.com> Acked-by: Don Zickus <dzickus@redhat.com> Acked-by: Prarit Bhargava <prarit@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, nmi: clean UP NMI watchdog failure messageIngo Molnar2008-08-15
| | | | | | | clean up the failure message - and redirect people to bugzilla instead of lkml. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, NMI: fix watchdog failure messageAristeu Rozanski2008-08-15
| | | | | | | | | | | | | | | | | | | | | | > it just won't work at boot time - the second logic unit will be stuck: > > Booting processor 1/2 APIC 0x1 > Initializing CPU#1 > Calibrating delay using timer specific routine.. 5586.12 BogoMIPS (lpj=2793063) > CPU: Trace cache: 12K uops, L1 D cache: 16K > CPU: L2 cache: 1024K > CPU: Physical Processor ID: 0 > CPU: Processor Core ID: 1 > CPU1: Thermal monitoring enabled (TM1) > Intel(R) Pentium(R) D CPU 2.80GHz stepping 04 > Brought up 2 CPUs > testing NMI watchdog ... <4>WARNING: CPU#1: NMI appears to be stuck (0->0)! while at it... - fix that newline Signed-off-by: Aristeu Rozanski <aris@redhat.com> Cc: jvillalo@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
*-----. Merge branches 'x86/urgent', 'x86/amd-iommu', 'x86/apic', 'x86/cleanups', ↵Ingo Molnar2008-07-21
|\ \ \ \ | | | | | | | | | | | | | | | 'x86/core', 'x86/cpu', 'x86/fixmap', 'x86/gart', 'x86/kprobes', 'x86/memtest', 'x86/modules', 'x86/nmi', 'x86/pat', 'x86/reboot', 'x86/setup', 'x86/step', 'x86/unify-pci', 'x86/uv', 'x86/xen' and 'xen-64bit' into x86/for-linus
| | | | * x86: add unknown_nmi_panic kernel parameterSimon Arlott2008-07-20
| |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's not possible to enable the unknown_nmi_panic sysctl option until init is run. It's useful to be able to panic the kernel during boot too, this adds a parameter to enable this option. Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | x86: APIC: remove apic_write_around(); use alternativesMaciej W. Rozycki2008-07-18
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use alternatives to select the workaround for the 11AP Pentium erratum for the affected steppings on the fly rather than build time. Remove the X86_GOOD_APIC configuration option and replace all the calls to apic_write_around() with plain apic_write(), protecting accesses to the ESR as appropriate due to the 3AP Pentium erratum. Remove apic_read_around() and all its invocations altogether as not needed. Remove apic_write_atomic() and all its implementing backends. The use of ASM_OUTPUT2() is not strictly needed for input constraints, but I have used it for readability's sake. I had the feeling no one else was brave enough to do it, so I went ahead and here it is. Verified by checking the generated assembly and tested with both a 32-bit and a 64-bit configuration, also with the 11AP "feature" forced on and verified with gdb on /proc/kcore to work as expected (as an 11AP machines are quite hard to get hands on these days). Some script complained about the use of "volatile", but apic_write() needs it for the same reason and is effectively a replacement for writel(), so I have disregarded it. I am not sure what the policy wrt defconfig files is, they are generated and there is risk of a conflict resulting from an unrelated change, so I have left changes to them out. The option will get removed from them at the next run. Some testing with machines other than mine will be needed to avoid some stupid mistake, but despite its volume, the change is not really that intrusive, so I am fairly confident that because it works for me, it will everywhere. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* / / Merge branch 'generic-ipi' into generic-ipi-for-linusIngo Molnar2008-07-15
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/powerpc/Kconfig arch/s390/kernel/time.c arch/x86/kernel/apic_32.c arch/x86/kernel/cpu/perfctr-watchdog.c arch/x86/kernel/i8259_64.c arch/x86/kernel/ldt.c arch/x86/kernel/nmi_64.c arch/x86/kernel/smpboot.c arch/x86/xen/smp.c include/asm-x86/hw_irq_32.h include/asm-x86/hw_irq_64.h include/asm-x86/mach-default/irq_vectors.h include/asm-x86/mach-voyager/irq_vectors.h include/asm-x86/smp.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
* / x86: Recover timer_ack lost in the merge of the NMI watchdogMaciej W. Rozycki2008-07-11
|/ | | | | | | | | | | | In the course of the recent unification of the NMI watchdog an assignment to timer_ack to switch off unnecesary POLL commands to the 8259A in the case of a watchdog failure has been accidentally removed. The statement used to be limited to the 32-bit variation as since the rewrite of the timer code it has been relevant for the 82489DX only. This change brings it back. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: nmi_watchdog - introduce nmi_watchdog_active() helperCyrill Gorcunov2008-07-08
| | | | | | Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Cc: macro@linux-mips.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: nmi_watchdog - use NMI_NONE by defaultCyrill Gorcunov2008-07-08
| | | | | | | | | | | | | | | There is no need to keep NMI_DISABLED definition and use it for nmi_watchdog by default. Here is the point why: - IO-APIC and APIC chips are programmed for nmi_watchdog support at very early stage of kernel booting and not having nmi_watchdog specified as boot option lead only to nmi_watchdog becomes to NMI_NONE anyway - enable nmi_watchdog thru /proc/sys/kernel/nmi if it was not specified at boot is not possible too (even having this sysfs entry) Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Cc: macro@linux-mips.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: nmi_watchdog - remove useless checkCyrill Gorcunov2008-07-08
| | | | | | | | | Since nmi_watchdog is unsigned variable we may safely remove the check for negative value. Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Cc: macro@linux-mips.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'x86/nmi' into x86/develIngo Molnar2008-07-08
| | | | | | | | | Conflicts: arch/x86/kernel/nmi.c arch/x86/kernel/nmi_32.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: fix typo CONFIX -> CONFIGGlauber Costa2008-06-19
| | | | Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: touch_nmi_watchdog(): reset alert counters for supported nmi_watchdog ↵Cyrill Gorcunov2008-06-12
| | | | | | | | | | | | | modes only The checking 'if nmi_watchdog > 0' (ie NMI_NONE) is quite fast but it has a side effect - it's taken even if nmi_watchdog = NMI_DISABLED. Nowadays nmi_watchdog is set up to NMI_NONE by default so this condition is properly taken most the time but we better show this explicitly. Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, nmi: fix buildmingo@elte.hu2008-06-05
| | | | | | | | | | | fix: arch/x86/kernel/built-in.o: In function `proc_nmi_enabled': : undefined reference to `nmi_watchdog_default' arch/x86/kernel/built-in.o: In function `native_smp_prepare_cpus': : undefined reference to `nmi_watchdog_default' Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: nmi - consolidate nmi_watchdog_default for 32bit modeCyrill Gorcunov2008-06-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | 64bit mode bootstrap code does set nmi_watchdog to NMI_NONE by default and doing the same on 32bit mode is safe too. Such an action saves us from several #ifdef. Btw, my previous commit commit 19ec673ced067316b9732bc6d1c4ff4052e5f795 Author: Cyrill Gorcunov <gorcunov@gmail.com> Date: Wed May 28 23:00:47 2008 +0400 x86: nmi - fix incorrect NMI watchdog used by default did not fix the problem completely, moreover it introduced additional bug - nmi_watchdog would be set to either NMI_LOCAL_APIC or NMI_IO_APIC _regardless_ to boot option if being enabled thru /proc/sys/kernel/nmi_watchdog. Sorry for that. Fix it too. Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Cc: mingo@redhat.com Cc: hpa@zytor.com Cc: macro@linux-mips.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86: fix nmi.c build bugIngo Molnar2008-06-02
| | | | apic.h needs to be included for the apic_write_around() definition.
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