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* Merge branch 'x86-uv-for-linus' of ↵Linus Torvalds2012-07-222-224/+257
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/uv changes from Ingo Molnar: "UV2 BAU productization fixes. The BAU (Broadcast Assist Unit) is SGI's fancy out of line way on UV hardware to do TLB flushes, instead of the normal APIC IPI methods. The commits here fix / work around hangs in their latest hardware iteration (UV2). My understanding is that the main purpose of the out of line signalling channel is to improve scalability: the UV APIC hardware glue does not handle broadcasting to many CPUs very well, and this matters most for TLB shootdowns. [ I don't agree with all aspects of the current approach: in hindsight it would have been better to link the BAU at the IPI/APIC driver level instead of the TLB shootdown level, where TLB flushes are really just one of the uses of broadcast SMP messages. Doing that would improve scalability in some other ways and it would also remove a few uglies from the TLB path. It would also be nice to push more is_uv_system() tests into proper x86_init or x86_platform callbacks. Cliff? ]" * 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/uv: Work around UV2 BAU hangs x86/uv: Implement UV BAU runtime enable and disable control via /proc/sgi_uv/ x86/uv: Fix the UV BAU destination timeout period
| * x86/uv: Work around UV2 BAU hangsCliff Wickman2012-06-252-215/+200
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On SGI's UV2 the BAU (Broadcast Assist Unit) driver can hang under a heavy load. To cure this: - Disable the UV2 extended status mode (see UV2_EXT_SHFT), as this mode changes BAU behavior in more ways then just delivering an extra bit of status. Revert status to just two meaningful bits, like UV1. - Use no IPI-style resets on UV2. Just give up the request for whatever the reason it failed and let it be accomplished with the legacy IPI method. - Use no alternate sending descriptor (the former UV2 workaround bcp->using_desc and handle_uv2_busy() stuff). Just disable the use of the BAU for a period of time in favor of the legacy IPI method when the h/w bug leaves a descriptor busy. -- new tunable: giveup_limit determines the threshold at which a hub is so plugged that it should do all requests with the legacy IPI method for a period of time -- generalize disable_for_congestion() (renamed disable_for_period()) for use whenever a hub should avoid using the BAU for a period of time Also: - Fix find_another_by_swack(), which is part of the UV2 bug workaround - Correct and clarify the statistics (new stats s_overipilimit, s_giveuplimit, s_enters, s_ipifordisabled, s_plugged, s_congested) Signed-off-by: Cliff Wickman <cpw@sgi.com> Link: http://lkml.kernel.org/r/20120622131459.GC31884@sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86/uv: Implement UV BAU runtime enable and disable control via /proc/sgi_uv/Cliff Wickman2012-06-252-15/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch enables the BAU to be turned on or off dynamically. echo "on" > /proc/sgi_uv/ptc_statistics echo "off" > /proc/sgi_uv/ptc_statistics The system may be booted with or without the nobau option. Whether the system currently has the BAU off can be seen in the /proc file -- normally with the baustats script. Each cpu will have a 1 in the bauoff field if the BAU was turned off, so baustats will give a count of cpus that have it off. Signed-off-by: Cliff Wickman <cpw@sgi.com> Link: http://lkml.kernel.org/r/20120622131330.GB31884@sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86/uv: Fix the UV BAU destination timeout periodCliff Wickman2012-06-251-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Correct the calculation of a destination timeout period, which is used to distinguish between a destination timeout and the situation where all the target software ack resources are full and a request is returned immediately. The problem is that integer arithmetic was overflowing, yielding a very large result. Without this fix destination timeouts are identified as resource 'plugged' events and an ipi method of resource releasing is unnecessarily employed. Signed-off-by: Cliff Wickman <cpw@sgi.com> Link: http://lkml.kernel.org/r/20120622131212.GA31884@sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'x86-reboot-for-linus' of ↵Linus Torvalds2012-07-227-46/+59
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/reboot changes from Ingo Molnar: "Now that the revampted x86 real-mode trampoline code is upstream and seems to be working well, we can extend the 64-bit reboot code to be as capable as the 32-bit one." * 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86-64, reboot: Be more paranoid in 64-bit reboot=bios x86, reboot: Drop redundant write of reboot_mode x86-64, reboot: Allow reboot=bios and reboot-cpu override on x86-64
| * | x86-64, reboot: Be more paranoid in 64-bit reboot=biosH. Peter Anvin2012-06-211-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Be a bit more paranoid in the transition back to 16-bit mode. In particular, in case the kernel is residing above the 4 GiB mark, switch to the trampoline GDT, and make the jump after turning off paging a far jump. In theory, none of this should matter, but it is exactly the kind of things that broken SMM or virtualization software could trip up on. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/tip-jopx7y6g6dbcx4tpal8q0jlr@git.kernel.org
| * | x86, reboot: Drop redundant write of reboot_modeH. Peter Anvin2012-06-201-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We write reboot_mode to BIOS location 0x472 in native_machine_emergency_restart() (reboot.c:542) already, there is no need to then write it again in machine_real_restart(). This means nothing gets written there for MRR_APM, but the APM call is a poweroff call and doesn't use this memory location. Link: http://lkml.kernel.org/n/tip-3i0pfh44c1e3jv5lab0cf7sc@git.kernel.org Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | x86-64, reboot: Allow reboot=bios and reboot-cpu override on x86-64H. Peter Anvin2012-06-177-38/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the revamped realmode trampoline code, it is trivial to extend support for reboot=bios to x86-64. Furthermore, while we are at it, remove the restriction that only we can only override the reboot CPU on 32 bits. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/n/tip-jopx7y6g6dbcx4tpal8q0jlr@git.kernel.org
* | | Merge branch 'x86-platform-for-linus' of ↵Linus Torvalds2012-07-2225-581/+429
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 platform changes from Ingo Molnar: "This tree mostly involves various APIC driver cleanups/robustization, and vSMP motivated platform callback improvements/cleanups" Fix up trivial conflict due to printk cleanup right next to return value change. * 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits) Revert "x86/early_printk: Replace obsolete simple_strtoul() usage with kstrtoint()" x86/apic/x2apic: Use multiple cluster members for the irq destination only with the explicit affinity x86/apic/x2apic: Limit the vector reservation to the user specified mask x86/apic: Optimize cpu traversal in __assign_irq_vector() using domain membership x86/vsmp: Fix vector_allocation_domain's return value irq/apic: Use config_enabled(CONFIG_SMP) checks to clean up irq_set_affinity() for UP x86/vsmp: Fix linker error when CONFIG_PROC_FS is not set x86/apic/es7000: Make apicid of a cluster (not CPU) from a cpumask x86/apic/es7000+summit: Always make valid apicid from a cpumask x86/apic/es7000+summit: Fix compile warning in cpu_mask_to_apicid() x86/apic: Fix ugly casting and branching in cpu_mask_to_apicid_and() x86/apic: Eliminate cpu_mask_to_apicid() operation x86/x2apic/cluster: Vector_allocation_domain() should return a value x86/apic/irq_remap: Silence a bogus pr_err() x86/vsmp: Ignore IOAPIC IRQ affinity if possible x86/apic: Make cpu_mask_to_apicid() operations check cpu_online_mask x86/apic: Make cpu_mask_to_apicid() operations return error code x86/apic: Avoid useless scanning thru a cpumask in assign_irq_vector() x86/apic: Try to spread IRQ vectors to different priority levels x86/apic: Factor out default vector_allocation_domain() operation ...
| * | | Revert "x86/early_printk: Replace obsolete simple_strtoul() usage with ↵Ingo Molnar2012-07-221-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kstrtoint()" This reverts commit fbd24153c48b8425b09c161a020483cd77da870e. This commit is subtly buggy: kstrto*int() can return an error but it's not checked in every path. simple_strtoul() on the other hand could not fail, so this patch subtly intruduces new failure modes. Signed-off-by: Shuah Khan <shuahkhan@gmail.com> Link: http://lkml.kernel.org/r/1338424803.3569.5.camel@lorien2 Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/apic/x2apic: Use multiple cluster members for the irq destination only ↵Suresh Siddha2012-07-061-2/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | with the explicit affinity During boot or driver load etc, interrupt destination is setup using default target cpu's. Later the user (irqbalance etc) or the driver (irq_set_affinity/ irq_set_affinity_hint) can request the interrupt to be migrated to some specific set of cpu's. In the x2apic cluster routing, for the default scenario use single cpu as the interrupt destination and when there is an explicit interrupt affinity request, route the interrupt to multiple members of a x2apic cluster specified in the cpumask of the migration request. This will minmize the vector pressure when there are lot of interrupt sources and relatively few x2apic clusters (for example a single socket server). This will allow the performance critical interrupts to be routed to multiple cpu's in the x2apic cluster (irqbalance for example uses the cache siblings etc while specifying the interrupt destination) and allow non-critical interrupts to be serviced by a single logical cpu. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Link: http://lkml.kernel.org/r/1340656709-11423-4-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/apic/x2apic: Limit the vector reservation to the user specified maskSuresh Siddha2012-07-065-24/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For the x2apic cluster mode, vector for an interrupt is currently reserved on all the cpu's that are part of the x2apic cluster. But the interrupts will be routed only to the cluster (derived from the first cpu in the mask) members specified in the mask. So there is no need to reserve the vector in the unused cluster members. Modify __assign_irq_vector() to reserve the vectors based on the user specified irq destination mask. If the new mask is a proper subset of the currently used mask, cleanup the vector allocation on the unused cpu members. Also, allow the apic driver to tune the vector domain based on the affinity mask (which in most cases is the user-specified mask). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Link: http://lkml.kernel.org/r/1340656709-11423-3-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/apic: Optimize cpu traversal in __assign_irq_vector() using domain ↵Suresh Siddha2012-07-065-18/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | membership Currently __assign_irq_vector() goes through each cpu in the specified mask until it finds a free vector in all the cpu's that are part of the same interrupt domain. We visit all the interrupt domain sibling cpus to reserve the free vector. So, when we fail to find a free vector in an interrupt domain, it is safe to continue our search with a cpu belonging to a new interrupt domain. No need to go through each cpu, if the domain containing that cpu is already visited. Use the irq_cfg's old_domain to track the visited domains and optimize the cpu traversal while finding a free vector in the given cpumask. NOTE: We can also optimize the search by using for_each_cpu() and skip the current cpu, if it is not the first cpu in the mask returned by the vector_allocation_domain(). But re-using the cfg->old_domain to track the visited domains will be slightly faster. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Link: http://lkml.kernel.org/r/1340656709-11423-2-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/vsmp: Fix vector_allocation_domain's return valueIdo Yariv2012-06-181-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 8637e38a ("x86/apic: Avoid useless scanning thru a cpumask in assign_irq_vector()") modified vector_allocation_domain() to return a boolean indicating if cpumask is dynamic or static. Adjust vSMP's callback implementation accordingly. Signed-off-by: Ido Yariv <ido@wizery.com> Acked-by: Shai Fultheim <shai@scalemp.com> Cc: Alexander Gordeev <agordeev@redhat.com> Link: http://lkml.kernel.org/r/1339773055-27397-1-git-send-email-ido@wizery.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | Merge branch 'x86/apic' into x86/platformIngo Molnar2012-06-1824-562/+359
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | Merge in x86/apic to solve a vector_allocation_domain() API change semantic merge conflict. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | irq/apic: Use config_enabled(CONFIG_SMP) checks to clean up ↵Suresh Siddha2012-06-155-110/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | irq_set_affinity() for UP Move the ->irq_set_affinity() routines out of the #ifdef CONFIG_SMP sections and use config_enabled(CONFIG_SMP) checks inside those routines. Thus making those routines simple null stubs for !CONFIG_SMP and retaining those routines with no additional runtime overhead for CONFIG_SMP kernels. Cleans up the ifdef CONFIG_SMP in and around routines related to irq_set_affinity in io_apic and irq_remapping subsystems. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: torvalds@linux-foundation.org Cc: joerg.roedel@amd.com Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Link: http://lkml.kernel.org/r/1339723729.3475.63.camel@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | Merge branch 'x86/cleanups' into x86/apicIngo Molnar2012-06-156-17/+12
| | |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge in the cleanups because a followup x86/apic change relies on them. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | x86/early_printk: Replace obsolete simple_strtoul() usage with kstrtoint()Shuah Khan2012-06-061-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change early_serial_init() to call kstrtoul() instead of calling obsoleted simple_strtoul(). Signed-off-by: Shuah Khan <shuahkhan@gmail.com> Cc: Joe Perches <joe@perches.com> Link: http://lkml.kernel.org/r/1338424803.3569.5.camel@lorien2 Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | x86: Return IRQ_SET_MASK_OK_NOCOPY from irq affinity functionsJiang Liu2012-05-242-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The interrupt chip irq_set_affinity() functions copy the affinity mask to irq_data->affinity but return 0, i.e. IRQ_SET_MASK_OK. IRQ_SET_MASK_OK causes the core code to do another redundant copy. Return IRQ_SET_MASK_OK_NOCOPY to avoid this. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Cliff Wickman <cpw@sgi.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Keping Chen <chenkeping@huawei.com> Link: http://lkml.kernel.org/r/1333120296-13563-4-git-send-email-jiang.liu@huawei.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | | * | | Revert "x86/platform: Add a wallclock_init func to x86_platforms ops"Feng Tang2012-05-243-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit cf8ff6b6ab0e99dd3058852f4ec76a6140abadec. Just found this commit is a function duplicatation of commit 6b617e22 "x86/platform: Add a wallclock_init func to x86_init.timers ops". Let's revert it and sorry for the noise. Signed-off-by: Feng Tang <feng.tang@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Alan Cox <alan@linux.intel.com> Cc: Dirk Brandewie <dirk.brandewie@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * | | | x86/apic/es7000: Make apicid of a cluster (not CPU) from a cpumaskAlexander Gordeev2012-06-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cpu_mask_to_apicid_and() always returns apicid of a single CPU, even in case multiple CPUs were requested. This update fixes a typo and forces apicid of a cluster to be returned. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120614075043.GI3383@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic/es7000+summit: Always make valid apicid from a cpumaskAlexander Gordeev2012-06-142-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case of invalid parameters cpu_mask_to_apicid_and() might return apicid value of 0 (on Summit) or a uninitialized value (on ES7000), although it is supposed to return apicid of cpu-0 at least. Fix the operation to always return a valid apicid. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120614075026.GH3383@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic/es7000+summit: Fix compile warning in cpu_mask_to_apicid()Alexander Gordeev2012-06-142-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120614075010.GG3383@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic: Fix ugly casting and branching in cpu_mask_to_apicid_and()Alexander Gordeev2012-06-144-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120614074954.GF3383@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic: Eliminate cpu_mask_to_apicid() operationAlexander Gordeev2012-06-1415-105/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since there are only two locations where cpu_mask_to_apicid() is called from, remove the operation and use only cpu_mask_to_apicid_and() instead. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Suggested-and-acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120614074935.GE3383@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/x2apic/cluster: Vector_allocation_domain() should return a valueAlexander Gordeev2012-06-141-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 8637e38 ("x86/apic: Avoid useless scanning thru a cpumask in assign_irq_vector()") vector_allocation_domain() operation indicates if a cpumask is dynamic or static. This update fixes the oversight and makes the operation to return a value. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120614103933.GJ3383@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic/irq_remap: Silence a bogus pr_err()Dan Carpenter2012-06-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is an extra semicolon here so the pr_err() message is printed when it is not intended. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Cc: Alexander Gordeev <agordeev@redhat.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Joerg Roedel <joerg.roedel@amd.com> Link: http://lkml.kernel.org/r/20120612162633.GA11077@elgon.mountain Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic: Make cpu_mask_to_apicid() operations check cpu_online_maskAlexander Gordeev2012-06-086-11/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently cpu_mask_to_apicid() should not get a offline CPU with the cpumask. Otherwise some apic drivers might try to access non-existent per-cpu variables (i.e. x2apic). In that regard cpu_mask_to_apicid() and cpu_mask_to_apicid_and() operations are inconsistent. This fix makes the two operations do not rely on calling functions and always return the apicid for only online CPUs. As result, the meaning and implementations of cpu_mask_to_apicid() and cpu_mask_to_apicid_and() operations become straight. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120607131624.GG4759@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic: Make cpu_mask_to_apicid() operations return error codeAlexander Gordeev2012-06-0810-105/+188
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current cpu_mask_to_apicid() and cpu_mask_to_apicid_and() implementations have few shortcomings: 1. A value returned by cpu_mask_to_apicid() is written to hardware registers unconditionally. Should BAD_APICID get ever returned it will be written to a hardware too. But the value of BAD_APICID is not universal across all hardware in all modes and might cause unexpected results, i.e. interrupts might get routed to CPUs that are not configured to receive it. 2. Because the value of BAD_APICID is not universal it is counter- intuitive to return it for a hardware where it does not make sense (i.e. x2apic). 3. cpu_mask_to_apicid_and() operation is thought as an complement to cpu_mask_to_apicid() that only applies a AND mask on top of a cpumask being passed. Yet, as consequence of 18374d8 commit the two operations are inconsistent in that of: cpu_mask_to_apicid() should not get a offline CPU with the cpumask cpu_mask_to_apicid_and() should not fail and return BAD_APICID These limitations are impossible to realize just from looking at the operations prototypes. Most of these shortcomings are resolved by returning a error code instead of BAD_APICID. As the result, faults are reported back early rather than possibilities to cause a unexpected behaviour exist (in case of [1]). The only exception is setup_timer_IRQ0_pin() routine. Although obviously controversial to this fix, its existing behaviour is preserved to not break the fragile check_timer() and would better addressed in a separate fix. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120607131559.GF4759@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic: Avoid useless scanning thru a cpumask in assign_irq_vector()Alexander Gordeev2012-06-083-7/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case of static vector allocation domains (i.e. flat) if all vector numbers are exhausted, an attempt to assign a new vector will lead to useless scans through all CPUs in the cpumask, even though it is known that each new pass would fail. Make this corner case less painful by letting report whether the vector allocation domain depends on passed arguments or not and stop scanning early. The same could have been achived by introducing a static flag to the apic operations. But let's allow vector_allocation_domain() have more intelligence here and decide dynamically, in case we would need it in the future. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120607131542.GE4759@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic: Try to spread IRQ vectors to different priority levelsAlexander Gordeev2012-06-081-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When assigning a new vector it is primarially done by adding 8 to the previously given out vector number. Hence, two consequently allocated vector numbers would likely fall into the same priority level. Try to spread vector numbers to different priority levels better by changing the step from 8 to 16. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120607131514.GD4759@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic: Factor out default vector_allocation_domain() operationAlexander Gordeev2012-06-0811-117/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120607131449.GC4759@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic: Factor out default cpu_mask_to_apicid() operationsAlexander Gordeev2012-06-068-139/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120605112340.GA11454@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic: Factor out default target_cpus() operationAlexander Gordeev2012-06-068-45/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120605112324.GA11449@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/apic: Trivial whitespace fixesAlexander Gordeev2012-06-063-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20120605112310.GA11443@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/x2apic/cluster: Use all the members of one cluster specified in the ↵Suresh Siddha2012-06-063-26/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | smp_affinity mask for the interrupt destination If the HW implements round-robin interrupt delivery, this enables multiple cpu's (which are part of the user specified interrupt smp_affinity mask and belong to the same x2apic cluster) to service the interrupt. Also if the platform supports Power Aware Interrupt Routing, then this enables the interrupt to be routed to an idle cpu or a busy cpu depending on the perf/power bias tunable. We are now grouping all the cpu's in a cluster to one vector domain. So that will limit the total number of interrupt sources handled by Linux. Previously we support "cpu-count * available-vectors-per-cpu" interrupt sources but this will now reduce to "cpu-count/16 * available-vectors-per-cpu". Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: yinghai@kernel.org Cc: gorcunov@openvz.org Cc: agordeev@redhat.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1337644682-19854-2-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | x86/irq: Update irq_cfg domain unless the new affinity is a subset of the ↵Suresh Siddha2012-06-061-9/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | current domain Until now, irq_cfg domain is mostly static. Either all CPU's (used by flat mode) or one CPU (first CPU in the irq afffinity mask) to which irq is being migrated (this is used by the rest of apic modes). Upcoming x2apic cluster mode optimization patch allows the irq to be sent to any CPU in the x2apic cluster (if supported by the HW). So irq_cfg domain changes on the fly (depending on which CPU in the x2apic cluster is online). Instead of checking for any intersection between the new irq affinity mask and the current irq_cfg domain, check if the new irq affinity mask is a subset of the current irq_cfg domain. Otherwise proceed with updating the irq_cfg domain aswell as assigning vector's on all the CPUs specified in the new mask. This also cleans up a workaround in updating irq_cfg domain for legacy irq's that are handled by the IO-APIC. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: yinghai@kernel.org Cc: gorcunov@openvz.org Cc: agordeev@redhat.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1337644682-19854-1-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | x86/vsmp: Fix linker error when CONFIG_PROC_FS is not setIdo Yariv2012-06-151-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | set_vsmp_pv_ops() references no_irq_affinity which is undeclared if CONFIG_PROC_FS isn't set. Fix this by adding an #ifdef around this variable's access. Reported-by: Fengguang Wu <wfg@linux.intel.com> Signed-off-by: Ido Yariv <ido@wizery.com> Acked-by: Shai Fultheim <shai@scalemp.com> Link: http://lkml.kernel.org/r/1339688588-12674-1-git-send-email-ido@wizery.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | x86/vsmp: Ignore IOAPIC IRQ affinity if possibleRavikiran Thirumalai2012-06-111-4/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vSMP can route interrupts more optimally based on internal knowledge the OS does not have. In order to support this optimization, all CPUs must be able to handle all possible IOAPIC interrupts. Fix this by setting the vector allocation domain for all CPUs and by enabling this feature in vSMP. Signed-off-by: Ravikiran Thirumalai <kiran.thirumalai@gmail.com> Signed-off-by: Shai Fultheim <shai@scalemp.com> [ Rebased, simplified, and reworded the commit message. ] Signed-off-by: Ido Yariv <ido@wizery.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | x86/platform: Introduce APIC post-initialization callbackIdo Yariv2012-06-064-9/+20
| |/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some subarchitectures (such as vSMP) need to slightly adjust the underlying APIC structure. Add an APIC post-initialization callback to 'struct x86_platform_ops' for this purpose and use it for adjusting the APIC structure on vSMP systems. Signed-off-by: Ido Yariv <ido@wizery.com> Acked-by: Shai Fultheim <shai@scalemp.com> Link: http://lkml.kernel.org/r/1338675095-27260-1-git-send-email-ido@wizery.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | Merge branch 'x86-debug-for-linus' of ↵Linus Torvalds2012-07-2235-316/+363
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull debug-for-linus git tree from Ingo Molnar. Fix up trivial conflict in arch/x86/kernel/cpu/perf_event_intel.c due to a printk() having changed to a pr_info() differently in the two branches. * 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Move call to print_modules() out of show_regs() x86/mm: Mark free_initrd_mem() as __init x86/microcode: Mark microcode_id[] as __initconst x86/nmi: Clean up register_nmi_handler() usage x86: Save cr2 in NMI in case NMIs take a page fault (for i386) x86: Remove cmpxchg from i386 NMI nesting code x86: Save cr2 in NMI in case NMIs take a page fault x86/debug: Add KERN_<LEVEL> to bare printks, convert printks to pr_<level>
| * | | | | x86: Move call to print_modules() out of show_regs()Jan Beulich2012-06-203-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Printing the list of loaded modules is really unrelated to what this function is about, and is particularly unnecessary in the context of the SysRQ key handling (gets printed so far over and over). It should really be the caller of the function to decide whether this piece of information is useful (and to avoid redundantly printing it). Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4FDF21A4020000780008A67F@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | x86/mm: Mark free_initrd_mem() as __initJan Beulich2012-06-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ... matching various other architectures. Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4FDF1F5C020000780008A661@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | x86/microcode: Mark microcode_id[] as __initconstJan Beulich2012-06-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's not being used for other than creating module aliases (i.e. no loadable section has any reference to it). Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4FDF1EFD020000780008A65D@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | x86/nmi: Clean up register_nmi_handler() usageLi Zhong2012-06-202-20/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement a cleaner and easier to maintain version for the section warning fixes implemented in commit eeaaa96a3a21 ("x86/nmi: Fix section mismatch warnings on 32-bit"). Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Jan Beulich <JBeulich@suse.com> Link: http://lkml.kernel.org/r/1340049393-17771-1-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | Merge commit 'v3.5-rc3' into x86/debugIngo Molnar2012-06-20456-2839/+6337
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge it in to pick up a fix that we are going to clean up in this branch. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | x86: Save cr2 in NMI in case NMIs take a page fault (for i386)Steven Rostedt2012-06-081-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Rostedt2012-06-081-14/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Save cr2 in NMI in case NMIs take a page faultSteven Rostedt2012-06-071-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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. Originally I wrote a patch to solve this by saving the cr2 on the stack. Brian Gerst suggested to save it in the r12 register as both r12 and rbx are saved by the do_nmi handler as required by the C standard. But rbx is already used for saving if swapgs needs to be run on exit of the NMI handler. Link: http://lkml.kernel.org/r/4FBB8C40.6080304@redhat.com Link: http://lkml.kernel.org/r/1337763411.13348.140.camel@gandalf.stny.rr.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> Suggested-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | | | | x86/debug: Add KERN_<LEVEL> to bare printks, convert printks to pr_<level>Joe Perches2012-06-0629-279/+301
| | |/ / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use a more current logging style: - Bare printks should have a KERN_<LEVEL> for consistency's sake - Add pr_fmt where appropriate - Neaten some macro definitions - Convert some Ok output to OK - Use "%s: ", __func__ in pr_fmt for summit - Convert some printks to pr_<level> Message output is not identical in all cases. Signed-off-by: Joe Perches <joe@perches.com> Cc: levinsasha928@gmail.com Link: http://lkml.kernel.org/r/1337655007.24226.10.camel@joe2Laptop [ merged two similar patches, tidied up the changelog ] Signed-off-by: Ingo Molnar <mingo@kernel.org>