talos-op-linux/arch/x86/kernel/apic, branch master

Merge tag 'x86-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-02-09T20:11:12+00:00

Pull x86 fixes from Thomas Gleixner: "A set of fixes for X86: - Ensure that the PIT is set up when the local APIC is disable or configured in legacy mode. This is caused by an ordering issue introduced in the recent changes which skip PIT initialization when the TSC and APIC frequencies are already known. - Handle malformed SRAT tables during early ACPI parsing which caused an infinite loop anda boot hang. - Fix a long standing race in the affinity setting code which affects PCI devices with non-maskable MSI interrupts. The problem is caused by the non-atomic writes of the MSI address (destination APIC id) and data (vector) fields which the device uses to construct the MSI message. The non-atomic writes are mandated by PCI. If both fields change and the device raises an interrupt after writing address and before writing data, then the MSI block constructs a inconsistent message which causes interrupts to be lost and subsequent malfunction of the device. The fix is to redirect the interrupt to the new vector on the current CPU first and then switch it over to the new target CPU. This allows to observe an eventually raised interrupt in the transitional stage (old CPU, new vector) to be observed in the APIC IRR and retriggered on the new target CPU and the new vector. The potential spurious interrupts caused by this are harmless and can in the worst case expose a buggy driver (all handlers have to be able to deal with spurious interrupts as they can and do happen for various reasons). - Add the missing suspend/resume mechanism for the HYPERV hypercall page which prevents resume hibernation on HYPERV guests. This change got lost before the merge window. - Mask the IOAPIC before disabling the local APIC to prevent potentially stale IOAPIC remote IRR bits which cause stale interrupt lines after resume" * tag 'x86-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic: Mask IOAPIC entries when disabling the local APIC x86/hyperv: Suspend/resume the hypercall page for hibernation x86/apic/msi: Plug non-maskable MSI affinity race x86/boot: Handle malformed SRAT tables during early ACPI parsing x86/timer: Don't skip PIT setup when APIC is disabled or in legacy mode

x86/apic: Mask IOAPIC entries when disabling the local APIC

2020-02-07T14:32:16+00:00

When a system suspends, the local APIC is disabled in the suspend sequence, but the IOAPIC is left in the current state. This means unmasked interrupt lines stay unmasked. This is usually the case for IOAPIC pin 9 to which the ACPI interrupt is connected. That means that in suspended state the IOAPIC can respond to an external interrupt, e.g. the wakeup via keyboard/RTC/ACPI, but the interrupt message cannot be handled by the disabled local APIC. As a consequence the Remote IRR bit is set, but the local APIC does not send an EOI to acknowledge it. This causes the affected interrupt line to become stale and the stale Remote IRR bit will cause a hang when __synchronize_hardirq() is invoked for that interrupt line. To prevent this, mask all IOAPIC entries before disabling the local APIC. The resume code already has the unmask operation inside. [ tglx: Massaged changelog ] Signed-off-by: Tony W Wang-oc Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/1579076539-7267-1-git-send-email-TonyWWang-oc@zhaoxin.com

x86/apic/msi: Plug non-maskable MSI affinity race

2020-02-01T08:31:47+00:00

Evan tracked down a subtle race between the update of the MSI message and the device raising an interrupt internally on PCI devices which do not support MSI masking. The update of the MSI message is non-atomic and consists of either 2 or 3 sequential 32bit wide writes to the PCI config space. - Write address low 32bits - Write address high 32bits (If supported by device) - Write data When an interrupt is migrated then both address and data might change, so the kernel attempts to mask the MSI interrupt first. But for MSI masking is optional, so there exist devices which do not provide it. That means that if the device raises an interrupt internally between the writes then a MSI message is sent built from half updated state. On x86 this can lead to spurious interrupts on the wrong interrupt vector when the affinity setting changes both address and data. As a consequence the device interrupt can be lost causing the device to become stuck or malfunctioning. Evan tried to handle that by disabling MSI accross an MSI message update. That's not feasible because disabling MSI has issues on its own: If MSI is disabled the PCI device is routing an interrupt to the legacy INTx mechanism. The INTx delivery can be disabled, but the disablement is not working on all devices. Some devices lose interrupts when both MSI and INTx delivery are disabled. Another way to solve this would be to enforce the allocation of the same vector on all CPUs in the system for this kind of screwed devices. That could be done, but it would bring back the vector space exhaustion problems which got solved a few years ago. Fortunately the high address (if supported by the device) is only relevant when X2APIC is enabled which implies interrupt remapping. In the interrupt remapping case the affinity setting is happening at the interrupt remapping unit and the PCI MSI message is programmed only once when the PCI device is initialized. That makes it possible to solve it with a two step update: 1) Target the MSI msg to the new vector on the current target CPU 2) Target the MSI msg to the new vector on the new target CPU In both cases writing the MSI message is only changing a single 32bit word which prevents the issue of inconsistency. After writing the final destination it is necessary to check whether the device issued an interrupt while the intermediate state #1 (new vector, current CPU) was in effect. This is possible because the affinity change is always happening on the current target CPU. The code runs with interrupts disabled, so the interrupt can be detected by checking the IRR of the local APIC. If the vector is pending in the IRR then the interrupt is retriggered on the new target CPU by sending an IPI for the associated vector on the target CPU. This can cause spurious interrupts on both the local and the new target CPU. 1) If the new vector is not in use on the local CPU and the device affected by the affinity change raised an interrupt during the transitional state (step #1 above) then interrupt entry code will ignore that spurious interrupt. The vector is marked so that the 'No irq handler for vector' warning is supressed once. 2) If the new vector is in use already on the local CPU then the IRR check might see an pending interrupt from the device which is using this vector. The IPI to the new target CPU will then invoke the handler of the device, which got the affinity change, even if that device did not issue an interrupt 3) If the new vector is in use already on the local CPU and the device affected by the affinity change raised an interrupt during the transitional state (step #1 above) then the handler of the device which uses that vector on the local CPU will be invoked. expose issues in device driver interrupt handlers which are not prepared to handle a spurious interrupt correctly. This not a regression, it's just exposing something which was already broken as spurious interrupts can happen for a lot of reasons and all driver handlers need to be able to deal with them. Reported-by: Evan Green Debugged-by: Evan Green Signed-off-by: Thomas Gleixner Tested-by: Evan Green Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87imkr4s7n.fsf@nanos.tec.linutronix.de

x86/timer: Don't skip PIT setup when APIC is disabled or in legacy mode

2020-01-29T11:50:12+00:00

Tony reported a boot regression caused by the recent workaround for systems which have a disabled (clock gate off) PIT. On his machine the kernel fails to initialize the PIT because apic_needs_pit() does not take into account whether the local APIC interrupt delivery mode will actually allow to setup and use the local APIC timer. This should be easy to reproduce with acpi=off on the command line which also disables HPET. Due to the way the PIT/HPET and APIC setup ordering works (APIC setup can require working PIT/HPET) the information is not available at the point where apic_needs_pit() makes this decision. To address this, split out the interrupt mode selection from apic_intr_mode_init(), invoke the selection before making the decision whether PIT is required or not, and add the missing checks into apic_needs_pit(). Fixes: c8c4076723da ("x86/timer: Skip PIT initialization on modern chipsets") Reported-by: Anthony Buckley Tested-by: Anthony Buckley Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Cc: Daniel Drake Link: https://bugzilla.kernel.org/show_bug.cgi?id=206125 Link: https://lore.kernel.org/r/87sgk6tmk2.fsf@nanos.tec.linutronix.de

x86/apic/uv: Avoid unused variable warning

2020-01-17T13:34:41+00:00

When CONFIG_PROC_FS is disabled, the compiler warns about an unused variable: arch/x86/kernel/apic/x2apic_uv_x.c: In function 'uv_setup_proc_files': arch/x86/kernel/apic/x2apic_uv_x.c:1546:8: error: unused variable 'name' [-Werror=unused-variable] char *name = hubless ? "hubless" : "hubbed"; Simplify the code so this variable is no longer needed. Fixes: 8785968bce1c ("x86/platform/uv: Add UV Hubbed/Hubless Proc FS Files") Signed-off-by: Arnd Bergmann Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20191212140419.315264-1-arnd@arndb.de

Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-11-26T17:52:37+00:00

Pull x86 platform updates from Ingo Molnar: "UV platform updates (with a 'hubless' variant) and Jailhouse updates for better UART support" * 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/jailhouse: Only enable platform UARTs if available x86/jailhouse: Improve setup data version comparison x86/platform/uv: Account for UV Hubless in is_uvX_hub Ops x86/platform/uv: Check EFI Boot to set reboot type x86/platform/uv: Decode UVsystab Info x86/platform/uv: Add UV Hubbed/Hubless Proc FS Files x86/platform/uv: Setup UV functions for Hubless UV Systems x86/platform/uv: Add return code to UV BIOS Init function x86/platform/uv: Return UV Hubless System Type x86/platform/uv: Save OEM_ID from ACPI MADT probe

Merge branches 'core-objtool-for-linus', 'x86-cleanups-for-linus' and 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-11-26T16:21:54+00:00

Pull x86 objtool, cleanup, and apic updates from Ingo Molnar: "Objtool: - Fix a gawk 5.0 incompatibility in gen-insn-attr-x86.awk. Most distros are still on gawk 4.2.x. Cleanup: - Misc cleanups, plus the removal of obsolete code such as Calgary IOMMU support, which code hasn't seen any real testing in a long time and there's no known users left. apic: - Two changes: a cleanup and a fix for an (old) race for oneshot threaded IRQ handlers" * 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/insn: Fix awk regexp warnings * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Remove unused asm/rio.h x86: Fix typos in comments x86/pci: Remove #ifdef __KERNEL__ guard from x86/pci: Remove pci_64.h x86: Remove the calgary IOMMU driver x86/apic, x86/uprobes: Correct parameter names in kernel-doc comments x86/kdump: Remove the unused crash_copy_backup_region() x86/nmi: Remove stale EDAC include leftover * 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/ioapic: Rename misnamed functions x86/ioapic: Prevent inconsistent state when moving an interrupt

Merge tag 'printk-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

2019-11-26T03:40:40+00:00

Pull printk updates from Petr Mladek: - Allow to print symbolic error names via new %pe modifier. - Use pr_warn() instead of the remaining pr_warning() calls. Fix formatting of the related lines. - Add VSPRINTF entry to MAINTAINERS. * tag 'printk-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (32 commits) checkpatch: don't warn about new vsprintf pointer extension '%pe' MAINTAINERS: Add VSPRINTF tools lib api: Renaming pr_warning to pr_warn ASoC: samsung: Use pr_warn instead of pr_warning lib: cpu_rmap: Use pr_warn instead of pr_warning trace: Use pr_warn instead of pr_warning dma-debug: Use pr_warn instead of pr_warning vgacon: Use pr_warn instead of pr_warning fs: afs: Use pr_warn instead of pr_warning sh/intc: Use pr_warn instead of pr_warning scsi: Use pr_warn instead of pr_warning platform/x86: intel_oaktrail: Use pr_warn instead of pr_warning platform/x86: asus-laptop: Use pr_warn instead of pr_warning platform/x86: eeepc-laptop: Use pr_warn instead of pr_warning oprofile: Use pr_warn instead of pr_warning of: Use pr_warn instead of pr_warning macintosh: Use pr_warn instead of pr_warning idsn: Use pr_warn instead of pr_warning ide: Use pr_warn instead of pr_warning crypto: n2: Use pr_warn instead of pr_warning ...

x86/apic/32: Avoid bogus LDR warnings

2019-11-04T23:11:00+00:00

The removal of the LDR initialization in the bigsmp_32 APIC code unearthed a problem in setup_local_APIC(). The code checks unconditionally for a mismatch of the logical APIC id by comparing the early APIC id which was initialized in get_smp_config() with the actual LDR value in the APIC. Due to the removal of the bogus LDR initialization the check now can trigger on bigsmp_32 APIC systems emitting a warning for every booting CPU. This is of course a false positive because the APIC is not using logical destination mode. Restrict the check and the possibly resulting fixup to systems which are actually using the APIC in logical destination mode. [ tglx: Massaged changelog and added Cc stable ] Fixes: bae3a8d3308 ("x86/apic: Do not initialize LDR and DFR for bigsmp") Signed-off-by: Jan Beulich Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/666d8f91-b5a8-1afd-7add-821e72a35f03@suse.com

x86/apic, x86/uprobes: Correct parameter names in kernel-doc comments

2019-10-27T08:00:28+00:00

Rename parameter names to the correct ones used in the function. No functional changes. [ bp: Merge two patches into a single one. ] Signed-off-by: Yi Wang Signed-off-by: Borislav Petkov Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/1571816442-22494-1-git-send-email-wang.yi59@zte.com.cn