linux/arch/powerpc/kernel
Sam Bobroff 0aab374709 powerpc/powernv: Restore non-volatile CRs after nap
Patches 7cba160ad "powernv/cpuidle: Redesign idle states management"
and 77b54e9f2 "powernv/powerpc: Add winkle support for offline cpus"
use non-volatile condition registers (cr2, cr3 and cr4) early in the system
reset interrupt handler (system_reset_pSeries()) before it has been determined
if state loss has occurred. If state loss has not occurred, control returns via
the power7_wakeup_noloss() path which does not restore those condition
registers, leaving them corrupted.

Fix this by restoring the condition registers in the power7_wakeup_noloss()
case.

This is apparent when running a KVM guest on hardware that does not
support winkle or sleep and the guest makes use of secondary threads. In
practice this means Power7 machines, though some early unreleased Power8
machines may also be susceptible.

The secondary CPUs are taken off line before the guest is started and
they call pnv_smp_cpu_kill_self(). This checks support for sleep
states (in this case there is no support) and power7_nap() is called.

When the CPU is woken, power7_nap() returns and because the CPU is
still off line, the main while loop executes again. The sleep states
support test is executed again, but because the tested values cannot
have changed, the compiler has optimized the test away and instead we
rely on the result of the first test, which has been left in cr3
and/or cr4. With the result overwritten, the wrong branch is taken and
power7_winkle() is called on a CPU that does not support it, leading
to it stalling.

Fixes: 7cba160ad7 ("powernv/cpuidle: Redesign idle states management")
Fixes: 77b54e9f21 ("powernv/powerpc: Add winkle support for offline cpus")
[mpe: Massage change log a bit more]
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-05-01 16:55:11 +10:00
..
vdso32 powerpc: 32 bit getcpu VDSO function uses 64 bit instructions 2014-11-27 09:42:12 +11:00
vdso64 powerpc/booke64: Use SPRG7 for VDSO 2014-03-19 19:57:14 -05:00
.gitignore
Makefile powerpc: kill PPC_OF 2015-03-17 20:04:32 +11:00
align.c powerpc: Remove double braces in alignment code. 2014-11-10 09:59:32 +11:00
asm-offsets.c KVM: PPC: Book3S HV: Use msgsnd for signalling threads on POWER8 2015-04-21 15:21:34 +02:00
audit.c
btext.c powerpc/btext: Fix CONFIG_PPC_EARLY_DEBUG_BOOTX on ppc32 2013-08-27 16:01:23 +10:00
cacheinfo.c powerpc: Fix missing L2 cache size in /sys/devices/system/cpu 2015-04-11 20:49:28 +10:00
cacheinfo.h
compat_audit.c
cpu_setup_6xx.S
cpu_setup_44x.S
cpu_setup_fsl_booke.S powerpc/booke: Restrict SPE exception handlers to e200/e500 cores 2014-09-22 10:11:31 +02:00
cpu_setup_pa6t.S
cpu_setup_power.S powerpc/book3s: Fix flush_tlb cpu_spec hook to take a generic argument. 2015-03-17 07:52:48 +11:00
cpu_setup_ppc970.S
cputable.c powerpc updates for 4.1 2015-04-16 13:53:32 -05:00
crash.c arch,powerpc: Convert smp_mb__*() 2014-04-18 14:20:41 +02:00
crash_dump.c powerpc: Remove superfluous bootmem includes 2014-11-10 09:59:26 +11:00
dbell.c powerpc/powernv: Fixes for hypervisor doorbell handling 2015-03-20 14:51:53 +11:00
dma-iommu.c powerpc/iommu: Rename iommu_[un]map_sg functions 2014-11-18 11:30:01 +01:00
dma-swiotlb.c powerpc: fsl_pci, swiotlb: Move controller ops from ppc_md to controller_ops 2015-04-11 20:49:17 +10:00
dma.c powerpc: Only do dynamic DMA zone limits on platforms that need it 2014-10-17 09:21:44 +11:00
eeh.c powerpc/eeh: Delay probing EEH device during hotplug 2015-05-01 13:52:32 +10:00
eeh_cache.c powerpc/eeh: Remove device_node dependency 2015-03-24 13:15:53 +11:00
eeh_dev.c powerpc/eeh: Create eeh_dev from pci_dn instead of device_node 2015-03-24 13:15:51 +11:00
eeh_driver.c powerpc/eeh: Remove device_node dependency 2015-03-24 13:15:53 +11:00
eeh_event.c powerpc/powernv: Fix killed EEH event 2014-06-11 17:04:33 +10:00
eeh_pe.c powerpc/eeh: Fix PE#0 check in eeh_add_to_parent_pe() 2015-03-31 13:10:39 +11:00
eeh_sysfs.c powerpc/eeh: Fix PE state format 2014-11-27 09:32:58 +11:00
entry_32.S powerpc: Remove old compile time disabled syscall tracing code 2015-02-02 14:51:32 +11:00
entry_64.S Revert "powerpc/tm: Abort syscalls in active transactions" 2015-04-30 15:24:58 +10:00
epapr_hcalls.S powerpc: Add paravirt idle loop for 64-bit Book-E 2013-03-13 14:19:36 -05:00
epapr_paravirt.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2014-06-10 18:54:22 -07:00
exceptions-64e.S powerpc/booke: Revert SPE/AltiVec common defines for interrupt numbers 2014-09-22 10:11:31 +02:00
exceptions-64s.S powerpc/book3s: Fix the MCE code to use CONFIG_KVM_BOOK3S_64_HANDLER 2015-03-23 17:10:47 +11:00
fadump.c powerpc/fadump: Fix endianess issues in firmware assisted dump handling 2014-10-30 16:52:46 +11:00
firmware.c
fpu.S powerpc: Don't corrupt transactional state when using FP/VMX in kernel 2014-01-15 13:59:11 +11:00
fsl_booke_entry_mapping.S powerpc: enable the relocatable support for the fsl booke 32bit kernel 2014-01-09 17:52:16 -06:00
ftrace.c powerpc updates for 3.19 2014-12-11 17:48:14 -08:00
head_8xx.S powerpc/8xx: Remove duplicated code in set_context() 2015-01-29 21:59:02 -06:00
head_32.S
head_40x.S powerpc: Remove check for CONFIG_SERIAL_TEXT_DEBUG 2014-06-11 16:31:21 +10:00
head_44x.S powerpc/ppc476: Disable BTAC 2014-08-13 15:13:42 +10:00
head_64.S Merge remote-tracking branch 'scott/next' into next 2014-08-05 14:13:41 +10:00
head_booke.h powerpc: Fix interrupt range check on debug exception 2013-05-02 10:31:01 +10:00
head_fsl_booke.S powerpc/booke: Revert SPE/AltiVec common defines for interrupt numbers 2014-09-22 10:11:31 +02:00
hw_breakpoint.c powerpc: Replace __get_cpu_var uses 2014-11-03 12:12:32 +11:00
ibmebus.c powerpc: make of_device_ids const 2014-09-25 23:14:46 +10:00
idle.c powerpc/idle: Convert use of typedef ctl_table to struct ctl_table 2013-07-01 11:10:35 +10:00
idle_6xx.S powerpc: Use CURRENT_THREAD_INFO instead of open coded assembly 2012-07-11 14:18:22 +10:00
idle_book3e.S powerpc: No need to use dot symbols when branching to a function 2014-04-23 10:05:16 +10:00
idle_e500.S powerpc: Use CURRENT_THREAD_INFO instead of open coded assembly 2012-07-11 14:18:22 +10:00
idle_power4.S powerpc: No need to use dot symbols when branching to a function 2014-04-23 10:05:16 +10:00
idle_power7.S powerpc/powernv: Restore non-volatile CRs after nap 2015-05-01 16:55:11 +10:00
io-workarounds.c powerpc/mm/thp: Make page table walk safe against thp split/collapse 2015-04-17 11:23:39 +10:00
io.c powerpc/powernv: Add PIO accessors for Power8 LPC bus 2013-08-14 14:58:08 +10:00
iomap.c powerpc/kerenl: Enable EEH for IO accessors 2014-06-24 12:43:13 +10:00
iommu.c powerpc/iommu: Remove IOMMU device references via bus notifier 2015-03-04 13:19:33 +11:00
irq.c powerpc: Remove superfluous bootmem includes 2014-11-10 09:59:26 +11:00
isa-bridge.c POWERPC: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
jump_label.c
kgdb.c powerpc: Replace __get_cpu_var uses 2014-11-03 12:12:32 +11:00
kprobes.c powerpc: Replace __get_cpu_var uses 2014-11-03 12:12:32 +11:00
kvm.c At over 200 commits, covering almost all supported architectures, this 2014-06-04 08:47:12 -07:00
kvm_emul.S KVM: PPC: Not optimizing MSR_CE and MSR_ME with paravirt. 2012-05-30 11:43:11 +02:00
l2cr_6xx.S
legacy_serial.c powerpc: make of_device_ids const 2014-09-25 23:14:46 +10:00
machine_kexec.c powerpc: Fix endian issues in kexec and crash dump code 2014-02-11 11:24:52 +11:00
machine_kexec_32.c
machine_kexec_64.c kexec: add IND_FLAGS macro 2015-02-17 14:34:51 -08:00
mce.c powerpc: Replace __get_cpu_var uses 2014-11-03 12:12:32 +11:00
mce_power.c powerpc/book3s: Fix flush_tlb cpu_spec hook to take a generic argument. 2015-03-17 07:52:48 +11:00
misc.S powerpc: Rename __get_SP() to current_stack_pointer() 2014-10-15 11:23:20 +11:00
misc_32.S powerpc: Set the correct ksp_limit on ppc32 when switching to irq stack 2014-02-17 11:19:34 +11:00
misc_64.S powerpc: module: handle MODVERSION for .TOC. 2014-04-23 10:05:28 +10:00
module.c powerpc: Move local setup.h declarations to arch includes 2013-10-30 16:00:31 +11:00
module_32.c powerpc: Use pr_fmt in module loader code 2014-10-02 17:33:54 +10:00
module_64.c powerpc: Use pr_fmt in module loader code 2014-10-02 17:33:54 +10:00
msi.c PCI/MSI/PPC: Remove arch_msi_check_device() 2014-10-01 12:21:14 -06:00
nvram_64.c powerpc/rtas: Make timestamp related code y2038-safe 2015-03-23 14:06:11 +11:00
of_platform.c powerpc/eeh: Do probe on pci_dn 2015-03-24 13:15:52 +11:00
paca.c powerpc/kernel: Avoid memory corruption at early stage 2015-01-23 14:02:52 +11:00
pci-common.c Merge branch 'next-sriov' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc into next 2015-04-14 09:29:23 +10:00
pci-hotplug.c powerpc: Remove shims for pci_controller_ops operations 2015-04-11 20:49:18 +10:00
pci_32.c powerpc: Remove more traces of bootmem 2014-11-19 21:41:51 +11:00
pci_64.c powerpc updates for 3.19 2014-12-11 17:48:14 -08:00
pci_dn.c powerpc/powernv: Shift VF resource with an offset 2015-03-31 13:02:38 +11:00
pci_of_scan.c powerpc: Remove shims for pci_controller_ops operations 2015-04-11 20:49:18 +10:00
pmc.c
ppc32.h powerpc: switch to generic old sigaction() 2013-02-03 18:16:10 -05:00
ppc_ksyms.c powerpc: Rename __get_SP() to current_stack_pointer() 2014-10-15 11:23:20 +11:00
ppc_ksyms_32.c powerpc: Separate ppc32 symbol exports into ppc_ksyms_32.c 2014-09-25 23:14:40 +10:00
ppc_save_regs.S
proc_powerpc.c proc_powerpc: switch to fixed_size_llseek() 2013-06-29 12:57:50 +04:00
process.c powerpc/kernel: Rename copy_thread() 'arg' argument to 'kthread_arg' 2015-03-20 12:41:15 +11:00
prom.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2015-04-14 09:50:27 -07:00
prom_init.c powerpc: Reword the "returning from prom_init" message 2015-04-10 20:02:48 +10:00
prom_init_check.sh powerpc: Simplify symbol check in prom_init_check.sh 2014-09-25 23:14:46 +10:00
prom_parse.c powerpc: of_parse_dma_window should take a __be32 *dma_window 2013-08-14 15:33:26 +10:00
ptrace.c Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
ptrace32.c powerpc: move debug registers in a structure 2013-10-18 18:44:49 -05:00
reloc_32.S powerpc: Don't flush/invalidate the d/icache for an unknown relocation type 2013-07-01 11:10:34 +10:00
reloc_64.S powerpc: Align p_dyn, p_rela and p_st symbols 2014-03-07 13:50:19 +11:00
rtas-proc.c powerpc: LLVM complains about forward declaration of struct rtas_sensors 2014-11-10 09:59:32 +11:00
rtas-rtc.c
rtas.c powerpc: Replace mem_init_done with slab_is_available() 2015-04-10 20:02:48 +10:00
rtas_flash.c powerpc: Fix endianness of flash_block_list in rtas_flash 2014-07-28 11:30:54 +10:00
rtas_pci.c powerpc: move find_and_init_phbs() to pSeries specific code 2015-04-11 20:49:09 +10:00
rtasd.c powerpc: Make a bunch of things static 2014-09-25 23:14:41 +10:00
setup-common.c powerpc: Convert power off logic to pm_power_off 2014-11-03 12:12:51 +11:00
setup_32.c powerpc: Remove unused vgacon_remap_base & fix build break 2014-11-10 09:59:31 +11:00
setup_64.c powerpc updates for 4.1 2015-04-16 13:53:32 -05:00
signal.c powerpc: Use sigsp() 2014-08-06 13:04:32 +02:00
signal.h powerpc: Use get_signal() signal_setup_done() 2014-08-06 13:03:09 +02:00
signal_32.c all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
signal_64.c all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
smp-tbsync.c powerpc: Delete non-required instances of include <linux/init.h> 2014-01-15 13:46:44 +11:00
smp.c powerpc/smp: Wait until secondaries are active & online 2015-03-04 13:19:33 +11:00
stacktrace.c powerpc: Rename __get_SP() to current_stack_pointer() 2014-10-15 11:23:20 +11:00
suspend.c nosave: consolidate __nosave_{begin,end} in <asm/sections.h> 2014-10-09 22:26:04 -04:00
swsusp.c
swsusp_32.S
swsusp_64.c
swsusp_asm64.S powerpc: Only save/restore SDR1 if in hypervisor mode 2013-10-31 12:37:29 +11:00
swsusp_booke.S powerpc/fsl-booke: Use SPRN_SPRGn rather than mfsprg/mtsprg 2014-01-07 19:06:03 -06:00
sys_ppc32.c unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE 2013-05-09 13:46:38 -04:00
syscalls.c powerpc: Add a proper syscall for switching endianness 2015-03-28 22:03:40 +11:00
sysfs.c powerpc: Replace __get_cpu_var uses 2014-11-03 12:12:32 +11:00
systbl.S powerpc: Add a proper syscall for switching endianness 2015-03-28 22:03:40 +11:00
systbl_chk.c powerpc: Add a proper syscall for switching endianness 2015-03-28 22:03:40 +11:00
systbl_chk.sh
tau_6xx.c
time.c KVM: PPC: Book3S HV: Accumulate timing information for real-mode code 2015-04-21 15:21:31 +02:00
tm.S powerpc: Change vrX register defines to vX to match gcc and glibc 2015-03-16 18:32:11 +11:00
traps.c powerpc: Remove some unused functions 2015-01-28 15:00:24 +11:00
udbg.c powerpc: Remove the celleb support 2015-04-07 17:15:13 +10:00
udbg_16550.c powerpc: Fix bad NULL pointer check in udbg_uart_getc_poll() 2014-11-12 13:47:20 +11:00
uprobes.c uprobes/powerpc: Kill arch_uprobe->ainsn 2013-11-20 16:31:01 +01:00
vdso.c powerpc: Remove superfluous bootmem includes 2014-11-10 09:59:26 +11:00
vecemu.c powerpc: Put FP/VSX and VR state into structures 2013-10-11 17:26:49 +11:00
vector.S powerpc: Change vrX register defines to vX to match gcc and glibc 2015-03-16 18:32:11 +11:00
vio.c arch/powerpc: replace obsolete strict_strto* calls 2014-08-08 15:57:28 -07:00
vmlinux.lds.S powerpc/modules: Module CRC relocation fix causes perf issues 2013-07-24 14:18:43 +10:00