linux_dsm_epyc7002/arch/x86/kernel
Thomas Gleixner c8c4076723 x86/timer: Skip PIT initialization on modern chipsets
Recent Intel chipsets including Skylake and ApolloLake have a special
ITSSPRC register which allows the 8254 PIT to be gated.  When gated, the
8254 registers can still be programmed as normal, but there are no IRQ0
timer interrupts.

Some products such as the Connex L1430 and exone go Rugged E11 use this
register to ship with the PIT gated by default. This causes Linux to fail
to boot:

  Kernel panic - not syncing: IO-APIC + timer doesn't work! Boot with
  apic=debug and send a report.

The panic happens before the framebuffer is initialized, so to the user, it
appears as an early boot hang on a black screen.

Affected products typically have a BIOS option that can be used to enable
the 8254 and make Linux work (Chipset -> South Cluster Configuration ->
Miscellaneous Configuration -> 8254 Clock Gating), however it would be best
to make Linux support the no-8254 case.

Modern sytems allow to discover the TSC and local APIC timer frequencies,
so the calibration against the PIT is not required. These systems have
always running timers and the local APIC timer works also in deep power
states.

So the setup of the PIT including the IO-APIC timer interrupt delivery
checks are a pointless exercise.

Skip the PIT setup and the IO-APIC timer interrupt checks on these systems,
which avoids the panic caused by non ticking PITs and also speeds up the
boot process.

Thanks to Daniel for providing the changelog, initial analysis of the
problem and testing against a variety of machines.

Reported-by: Daniel Drake <drake@endlessm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Daniel Drake <drake@endlessm.com>
Cc: bp@alien8.de
Cc: hpa@zytor.com
Cc: linux@endlessm.com
Cc: rafael.j.wysocki@intel.com
Cc: hdegoede@redhat.com
Link: https://lkml.kernel.org/r/20190628072307.24678-1-drake@endlessm.com
2019-06-29 11:35:35 +02:00
..
acpi x86/power: Optimize C3 entry on Centaur CPUs 2019-04-19 19:28:06 +02:00
apic x86/timer: Skip PIT initialization on modern chipsets 2019-06-29 11:35:35 +02:00
cpu x86/apic: Rename 'lapic_timer_frequency' to 'lapic_timer_period' 2019-05-09 11:06:49 +02:00
fpu x86/fpu: Move init_xstate_size() to __init section 2019-02-08 14:32:34 +01:00
kprobes Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-06 16:13:31 -07:00
.gitignore
alternative.c x86/alternatives: Add comment about module removal races 2019-04-30 12:38:01 +02:00
amd_gart_64.c x86/amd_gart: fix unmapping of non-GART mappings 2019-01-05 08:27:32 +01:00
amd_nb.c x86/amd_nb: Add PCI device IDs for family 17h, model 30h 2018-11-07 21:36:09 +01:00
apb_timer.c
aperture_64.c x86/gart: Exclude GART aperture from kcore 2019-03-23 12:11:49 +01:00
apm_32.c x86/APM: Fix build warning when PROC_FS is not enabled 2018-09-15 10:16:25 +02:00
asm-offsets_32.c x86/entry/32: Load task stack from x86_tss.sp1 in SYSENTER handler 2018-07-20 01:11:36 +02:00
asm-offsets_64.c x86/irq/64: Split the IRQ stack into its own pages 2019-04-17 15:37:02 +02:00
asm-offsets.c x86/kernel: Fix more -Wmissing-prototypes warnings 2018-12-08 12:24:35 +01:00
audit_64.c
bootflag.c
check.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
cpuid.c
crash_dump_32.c
crash_dump_64.c x86: Fix various typos in comments 2018-12-03 10:49:13 +01:00
crash.c x86/kexec/crash: Use struct_size() in vzalloc() 2019-04-05 13:18:38 +02:00
devicetree.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
doublefault.c
dumpstack_32.c x86/irq/32: Rename hard/softirq_stack to hard/softirq_stack_ptr 2019-04-17 15:24:18 +02:00
dumpstack_64.c x86/irq/64: Rename irq_stack_ptr to hardirq_stack_ptr 2019-04-17 15:27:10 +02:00
dumpstack.c x86/process: Don't mix user/kernel regs in 64bit __show_regs() 2018-09-06 14:33:12 +02:00
e820.c Merge branch 'akpm' (patches from Andrew) 2019-03-12 10:39:53 -07:00
early_printk.c efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation 2019-02-04 08:27:30 +01:00
early-quirks.c On GEM side: 2018-07-20 12:29:24 +10:00
ebda.c
eisa.c x86/EISA: Don't probe EISA bus for Xen PV guests 2018-09-11 23:36:50 +02:00
espfix_64.c
ftrace_32.S
ftrace_64.S x86/ftrace: Do not call function graph from dynamic trampolines 2018-12-19 22:43:37 -05:00
ftrace.c x86/ftrace: Use vmalloc special flag 2019-04-30 12:38:00 +02:00
head32.c x86/boot: Mostly revert commit ae7e1238e6 ("Add ACPI RSDP address to setup_header") 2018-11-20 09:43:10 +01:00
head64.c x86/boot: Mostly revert commit ae7e1238e6 ("Add ACPI RSDP address to setup_header") 2018-11-20 09:43:10 +01:00
head_32.S x86/pgtable/32: Allocate 8k page-tables when PTI is enabled 2018-07-20 01:11:41 +02:00
head_64.S x86/irq/64: Split the IRQ stack into its own pages 2019-04-17 15:37:02 +02:00
hpet.c x86/hpet: Prevent potential NULL pointer dereference 2019-03-21 12:24:38 +01:00
hw_breakpoint.c x86/hw_breakpoints: Make default case in hw_breakpoint_arch_parse() return an error 2019-03-22 17:08:17 +01:00
i8237.c x86/i8237: Register device based on FADT legacy boot flag 2018-04-27 16:44:29 +02:00
i8253.c x86/timer: Skip PIT initialization on modern chipsets 2019-06-29 11:35:35 +02:00
i8259.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
idt.c x86/exceptions: Disconnect IST index and stack order 2019-04-17 15:01:09 +02:00
ima_arch.c x86/ima: retry detecting secure boot mode 2018-12-11 07:19:45 -05:00
io_delay.c
ioport.c
irq_32.c x86/irq/32: Handle irq stack allocation failure proper 2019-04-17 15:31:42 +02:00
irq_64.c x86/irq/64: Remove stack overflow debug code 2019-04-17 15:41:48 +02:00
irq_work.c
irq.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
irqflags.S x86/paravirt: Make native_save_fl() extern inline 2018-07-03 10:56:27 +02:00
irqinit.c x86/irq/32: Handle irq stack allocation failure proper 2019-04-17 15:31:42 +02:00
itmt.c
jailhouse.c x86/apic: Rename 'lapic_timer_frequency' to 'lapic_timer_period' 2019-05-09 11:06:49 +02:00
jump_label.c x86/jump-label: Remove support for custom text poker 2019-04-30 12:37:55 +02:00
kdebugfs.c
kexec-bzimage64.c Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-03-10 17:32:04 -07:00
kgdb.c x86/kgdb: Avoid redundant comparison of patched code 2019-04-30 12:37:53 +02:00
ksysfs.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
kvm.c x86/kvm: Make steal_time visible 2019-04-19 17:58:57 +02:00
kvmclock.c x86: kvmguest: use TSC clocksource if invariant TSC is exposed 2019-02-20 22:48:52 +01:00
ldt.c x86: Convert some slow-path static_cpu_has() callers to boot_cpu_has() 2019-04-08 12:13:34 +02:00
livepatch.c
machine_kexec_32.c x86/kexec: Allocate 8k PGDs for PTI 2018-07-30 13:53:48 +02:00
machine_kexec_64.c x86/kdump: Export the SME mask to vmcoreinfo 2019-01-11 16:09:25 +01:00
Makefile jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
mmconf-fam10h_64.c
module.c x86/modules: Avoid breaking W^X while loading modules 2019-04-30 12:37:55 +02:00
mpparse.c x86/mm: Don't leak kernel addresses 2019-03-19 12:10:56 +01:00
msr.c x86: Clean up 'sizeof x' => 'sizeof(x)' 2018-10-29 07:13:28 +01:00
nmi_selftest.c
nmi.c x86/exceptions: Split debug IST stack 2019-04-17 15:14:28 +02:00
paravirt_patch_32.c x86/paravirt: Remove unused _paravirt_ident_32 2018-10-30 09:55:31 +01:00
paravirt_patch_64.c x86/paravirt: Remove unused _paravirt_ident_32 2018-10-30 09:55:31 +01:00
paravirt-spinlocks.c x86/paravirt: Use a single ops structure 2018-09-03 16:50:35 +02:00
paravirt.c x86: Convert some slow-path static_cpu_has() callers to boot_cpu_has() 2019-04-08 12:13:34 +02:00
pci-calgary_64.c x86/calgary: remove the mapping_error dma_map_ops method 2018-12-06 06:56:46 -08:00
pci-dma.c dma-mapping: bypass indirect calls for dma-direct 2018-12-13 21:06:18 +01:00
pci-iommu_table.c x86/iommu: Use NULL instead of 0 2018-08-02 14:33:19 +02:00
pci-swiotlb.c dma-direct: merge swiotlb_dma_ops into the dma_direct code 2018-12-13 21:06:17 +01:00
pcspeaker.c x86/platform/pcspeaker: Use PTR_ERR_OR_ZERO() to fix ptr_ret.cocci warning 2018-07-24 09:46:42 +02:00
perf_regs.c perf/x86: Support outputting XMM registers 2019-04-16 12:19:36 +02:00
platform-quirks.c x86/i8237: Register device based on FADT legacy boot flag 2018-04-27 16:44:29 +02:00
pmem.c
probe_roms.c
process_32.c sched/x86: Save [ER]FLAGS on context switch 2019-04-03 09:36:27 +02:00
process_64.c sched/x86_64: Don't save flags on context switch 2019-04-03 11:02:24 +02:00
process.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-06 15:32:35 -07:00
process.h x86/speculation: Change misspelled STIPB to STIBP 2018-12-06 11:49:15 +01:00
ptrace.c x86/fsgsbase/64: Fix the base write helper functions 2018-12-18 14:26:09 +01:00
pvclock.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
quirks.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
reboot_fixups_32.c
reboot.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-06 15:32:35 -07:00
relocate_kernel_32.S
relocate_kernel_64.S
resource.c
rtc.c x86: Convert x86_platform_ops to timespec64 2018-05-19 14:03:14 +02:00
setup_percpu.c x86/irq/64: Split the IRQ stack into its own pages 2019-04-17 15:37:02 +02:00
setup.c Merge branch 'x86-kdump-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-06 16:11:45 -07:00
signal_compat.c signal: Add TRAP_UNK si_code for undiagnosted trap exceptions 2018-04-25 10:40:56 -05:00
signal.c Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-06 12:46:54 -07:00
smp.c x86/apic: Use non-atomic operations when possible 2019-06-23 14:07:23 +02:00
smpboot.c Merge branch 'x86-topology-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-06 16:33:06 -07:00
stacktrace.c x86/stacktrace: Use common infrastructure 2019-04-29 12:37:57 +02:00
step.c
sys_x86_64.c x86/compat: Adjust in_compat_syscall() to generic code under !COMPAT 2018-11-01 12:59:25 +01:00
sysfb_efi.c x86/kernel: Fix more -Wmissing-prototypes warnings 2018-12-08 12:24:35 +01:00
sysfb_simplefb.c
sysfb.c
tboot.c iommu/vtd: Cleanup dma_remapping.h header 2018-11-12 14:22:56 +01:00
tce_64.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
time.c x86/timer: Skip PIT initialization on modern chipsets 2019-06-29 11:35:35 +02:00
tls.c
tls.h
topology.c x86/topology: Make DEBUG_HOTPLUG_CPU0 pr_info() more descriptive 2019-04-19 19:42:57 +02:00
trace_clock.c
tracepoint.c x86/kernel: Fix more -Wmissing-prototypes warnings 2018-12-08 12:24:35 +01:00
traps.c Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-03-07 17:09:28 -08:00
tsc_msr.c x86/apic: Rename 'lapic_timer_frequency' to 'lapic_timer_period' 2019-05-09 11:06:49 +02:00
tsc_sync.c
tsc.c x86/tsc: Set LAPIC timer period to crystal clock frequency 2019-05-09 11:06:49 +02:00
umip.c signal/x86: Use force_sig_fault where appropriate 2018-09-21 15:30:54 +02:00
unwind_frame.c x86/unwind: Handle NULL pointer calls better in frame unwinder 2019-03-06 23:03:26 +01:00
unwind_guess.c
unwind_orc.c x86/unwind: Add hardcoded ORC entry for NULL 2019-03-06 23:03:26 +01:00
uprobes.c x86/kernel: Mark expected switch-case fall-throughs 2019-01-26 11:19:13 +01:00
verify_cpu.S
vm86_32.c x86: Convert some slow-path static_cpu_has() callers to boot_cpu_has() 2019-04-08 12:13:34 +02:00
vmlinux.lds.S Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-06 16:13:31 -07:00
vsmp_64.c x86/vsmp: Remove dependency on pv_irq_ops 2018-11-06 21:35:11 +01:00
x86_init.c x86/acpi, x86/boot: Take RSDP address for boot params if available 2018-10-10 10:44:22 +02:00