Shreyas B. Prabhu
b32aadc1a8
powerpc/powernv: Fix race in updating core_idle_state ...
core_idle_state is maintained for each core. It uses 0-7 bits to track
whether a thread in the core has entered fastsleep or winkle. 8th bit is
used as a lock bit.
The lock bit is set in these 2 scenarios-
- The thread is first in subcore to wakeup from sleep/winkle.
- If its the last thread in the core about to enter sleep/winkle
While the lock bit is set, if any other thread in the core wakes up, it
loops until the lock bit is cleared before proceeding in the wakeup
path. This helps prevent race conditions w.r.t fastsleep workaround and
prevents threads from switching to process context before core/subcore
resources are restored.
But, in the path to sleep/winkle entry, we currently don't check for
lock-bit. This exposes us to following race when running with subcore
on-
First thread in the subcorea Another thread in the same
waking up core entering sleep/winkle
lwarx r15,0,r14
ori r15,r15,PNV_CORE_IDLE_LOCK_BIT
stwcx. r15,0,r14
[Code to restore subcore state]
lwarx r15,0,r14
[clear thread bit]
stwcx. r15,0,r14
andi. r15,r15,PNV_CORE_IDLE_THREAD_BITS
stw r15,0(r14)
Here, after the thread entering sleep clears its thread bit in
core_idle_state, the value is overwritten by the thread waking up.
In such cases when the core enters fastsleep, code mistakes an idle
thread as running. Because of this, the first thread waking up from
fastsleep which is supposed to resync timebase skips it. So we can
end up having a core with stale timebase value.
This patch fixes the above race by looping on the lock bit even while
entering the idle states.
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Fixes: 7b54e9f213f76 'powernv/powerpc: Add winkle support for offline cpus'
Cc: stable@vger.kernel.org # 3.19+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-07-07 10:16:52 +10:00
powerpc: 32 bit getcpu VDSO function uses 64 bit instructions
2014-11-27 09:42:12 +11:00
powerpc/booke64: Use SPRG7 for VDSO
2014-03-19 19:57:14 -05:00
powerpc: Remove double braces in alignment code.
2014-11-10 09:59:32 +11:00
powerpc/kernel: Rename PACA_DSCR to PACA_DSCR_DEFAULT
2015-06-07 19:29:00 +10:00
powerpc/btext: Fix CONFIG_PPC_EARLY_DEBUG_BOOTX on ppc32
2013-08-27 16:01:23 +10:00
powerpc: Fix missing L2 cache size in /sys/devices/system/cpu
2015-04-11 20:49:28 +10:00
powerpc/booke: Restrict SPE exception handlers to e200/e500 cores
2014-09-22 10:11:31 +02:00
powerpc/book3s: Fix flush_tlb cpu_spec hook to take a generic argument.
2015-03-17 07:52:48 +11:00
powerpc/tm: Abort syscalls in active transactions
2015-06-19 17:10:28 +10:00
arch,powerpc: Convert smp_mb__*()
2014-04-18 14:20:41 +02:00
powerpc: Remove superfluous bootmem includes
2014-11-10 09:59:26 +11:00
powerpc/powernv: Fixes for hypervisor doorbell handling
2015-03-20 14:51:53 +11:00
powerpc/iommu: Rename iommu_[un]map_sg functions
2014-11-18 11:30:01 +01:00
powerpc: fsl_pci, swiotlb: Move controller ops from ppc_md to controller_ops
2015-04-11 20:49:17 +10:00
powerpc/pci: add dma_set_mask to pci_controller_ops
2015-06-02 13:18:49 +10:00
powerpc/eeh/ioda2: Use device::iommu_group to check IOMMU group
2015-06-11 15:14:54 +10:00
powerpc/eeh: fix start/end/flags type in struct pci_io_addr_range{}
2015-05-13 14:00:07 +10:00
powerpc/eeh: Create eeh_dev from pci_dn instead of device_node
2015-03-24 13:15:51 +11:00
powerpc/eeh: fix comment for wait_state()
2015-05-13 14:00:07 +10:00
powerpc/powernv: Fix killed EEH event
2014-06-11 17:04:33 +10:00
powerpc/eeh: Fix PE#0 check in eeh_add_to_parent_pe()
2015-03-31 13:10:39 +11:00
powerpc/eeh: Fix PE state format
2014-11-27 09:32:58 +11:00
powerpc: Remove old compile time disabled syscall tracing code
2015-02-02 14:51:32 +11:00
powerpc/tm: Abort syscalls in active transactions
2015-06-19 17:10:28 +10:00
powerpc: Add paravirt idle loop for 64-bit Book-E
2013-03-13 14:19:36 -05:00
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
2014-06-10 18:54:22 -07:00
powerpc/booke: Revert SPE/AltiVec common defines for interrupt numbers
2014-09-22 10:11:31 +02:00
powerpc: Non relocatable system call doesn't need a trampoline
2015-06-02 13:26:47 +10:00
powerpc/fadump: Fix endianess issues in firmware assisted dump handling
2014-10-30 16:52:46 +11:00
powerpc: Don't corrupt transactional state when using FP/VMX in kernel
2014-01-15 13:59:11 +11:00
powerpc: enable the relocatable support for the fsl booke 32bit kernel
2014-01-09 17:52:16 -06:00
powerpc updates for 3.19
2014-12-11 17:48:14 -08:00
powerpc/8xx: Implementation of PAGE_EXEC
2015-06-02 21:37:28 -05:00
powerpc: Call do_page_fault() with interrupts off
2012-03-09 10:55:08 +11:00
powerpc: Remove check for CONFIG_SERIAL_TEXT_DEBUG
2014-06-11 16:31:21 +10:00
powerpc/ppc476: Disable BTAC
2014-08-13 15:13:42 +10:00
Merge remote-tracking branch 'scott/next' into next
2014-08-05 14:13:41 +10:00
powerpc: Fix interrupt range check on debug exception
2013-05-02 10:31:01 +10:00
powerpc/booke: Revert SPE/AltiVec common defines for interrupt numbers
2014-09-22 10:11:31 +02:00
powerpc: Replace __get_cpu_var uses
2014-11-03 12:12:32 +11:00
powerpc: make of_device_ids const
2014-09-25 23:14:46 +10:00
powerpc/idle: Convert use of typedef ctl_table to struct ctl_table
2013-07-01 11:10:35 +10:00
powerpc: Use CURRENT_THREAD_INFO instead of open coded assembly
2012-07-11 14:18:22 +10:00
powerpc: No need to use dot symbols when branching to a function
2014-04-23 10:05:16 +10:00
powerpc/e500mc: Remove dead L2 flushing code in idle_e500.S
2015-06-02 21:37:19 -05:00
powerpc: No need to use dot symbols when branching to a function
2014-04-23 10:05:16 +10:00
powerpc/powernv: Fix race in updating core_idle_state
2015-07-07 10:16:52 +10:00
powerpc/mm/thp: Make page table walk safe against thp split/collapse
2015-04-17 11:23:39 +10:00
powerpc/powernv: Add PIO accessors for Power8 LPC bus
2013-08-14 14:58:08 +10:00
powerpc/kerenl: Enable EEH for IO accessors
2014-06-24 12:43:13 +10:00
powerpc/iommu/powernv: Release replaced TCE
2015-06-11 15:16:49 +10:00
powerpc: Remove superfluous bootmem includes
2014-11-10 09:59:26 +11:00
POWERPC: drivers: remove __dev* attributes.
2013-01-03 15:57:04 -08:00
powerpc: Replace __get_cpu_var uses
2014-11-03 12:12:32 +11:00
powerpc: Replace __get_cpu_var uses
2014-11-03 12:12:32 +11:00
At over 200 commits, covering almost all supported architectures, this
2014-06-04 08:47:12 -07:00
KVM: PPC: Not optimizing MSR_CE and MSR_ME with paravirt.
2012-05-30 11:43:11 +02:00
powerpc: make of_device_ids const
2014-09-25 23:14:46 +10:00
powerpc: Fix endian issues in kexec and crash dump code
2014-02-11 11:24:52 +11:00
kexec: add IND_FLAGS macro
2015-02-17 14:34:51 -08:00
Devicetree changes for v4.2
2015-07-01 19:40:18 -07:00
powerpc/mce: fix off by one errors in mce event handling
2015-05-12 19:44:01 +10:00
powerpc/book3s: Fix flush_tlb cpu_spec hook to take a generic argument.
2015-03-17 07:52:48 +11:00
powerpc: Rename __get_SP() to current_stack_pointer()
2014-10-15 11:23:20 +11:00
powerpc: Set the correct ksp_limit on ppc32 when switching to irq stack
2014-02-17 11:19:34 +11:00
powerpc: module: handle MODVERSION for .TOC.
2014-04-23 10:05:28 +10:00
powerpc: Move local setup.h declarations to arch includes
2013-10-30 16:00:31 +11:00
powerpc: Use pr_fmt in module loader code
2014-10-02 17:33:54 +10:00
powerpc: Use pr_fmt in module loader code
2014-10-02 17:33:54 +10:00
powerpc: Remove MSI-related PCI controller ops from ppc_md
2015-06-02 11:47:45 +10:00
powerpc/rtas: Make timestamp related code y2038-safe
2015-03-23 14:06:11 +11:00
powerpc/eeh: Do probe on pci_dn
2015-03-24 13:15:52 +11:00
powerpc/kernel: Avoid memory corruption at early stage
2015-01-23 14:02:52 +11:00
powerpc/pci: Add pcibios_disable_device() hook
2015-06-03 13:27:16 +10:00
powerpc/pci: Add release_device() hook to phb ops
2015-06-03 13:27:15 +10:00
powerpc: Remove more traces of bootmem
2014-11-19 21:41:51 +11:00
powerpc updates for 3.19
2014-12-11 17:48:14 -08:00
powerpc/powernv: Shift VF resource with an offset
2015-03-31 13:02:38 +11:00
powerpc: Remove shims for pci_controller_ops operations
2015-04-11 20:49:18 +10:00
powerpc: switch to generic old sigaction()
2013-02-03 18:16:10 -05:00
powerpc: Rename __get_SP() to current_stack_pointer()
2014-10-15 11:23:20 +11:00
powerpc: Separate ppc32 symbol exports into ppc_ksyms_32.c
2014-09-25 23:14:40 +10:00
proc_powerpc: switch to fixed_size_llseek()
2013-06-29 12:57:50 +04:00
powerpc/kernel: Remove the unused extern dscr_default
2015-06-07 19:27:26 +10:00
arm64 updates for 4.2, mostly refactoring/clean-up:
2015-06-24 10:02:15 -07:00
PCI: Remove unnecessary #includes of <asm/pci.h>
2015-06-08 07:56:09 -05:00
powerpc: Simplify symbol check in prom_init_check.sh
2014-09-25 23:14:46 +10:00
powerpc: of_parse_dma_window should take a __be32 *dma_window
2013-08-14 15:33:26 +10:00
Merge git://git.infradead.org/users/eparis/audit
2014-10-19 16:25:56 -07:00
powerpc: move debug registers in a structure
2013-10-18 18:44:49 -05:00
powerpc: Don't flush/invalidate the d/icache for an unknown relocation type
2013-07-01 11:10:34 +10:00
powerpc: Align p_dyn, p_rela and p_st symbols
2014-03-07 13:50:19 +11:00
powerpc: LLVM complains about forward declaration of struct rtas_sensors
2014-11-10 09:59:32 +11:00
powerpc: Replace mem_init_done with slab_is_available()
2015-04-10 20:02:48 +10:00
powerpc: Fix endianness of flash_block_list in rtas_flash
2014-07-28 11:30:54 +10:00
powerpc: move find_and_init_phbs() to pSeries specific code
2015-04-11 20:49:09 +10:00
powerpc: Make a bunch of things static
2014-09-25 23:14:41 +10:00
powerpc: Convert power off logic to pm_power_off
2014-11-03 12:12:51 +11:00
powerpc: Remove unused vgacon_remap_base & fix build break
2014-11-10 09:59:31 +11:00
powerpc/mmu: Add userspace-to-physical addresses translation cache
2015-06-11 15:16:54 +10:00
powerpc: Use sigsp()
2014-08-06 13:04:32 +02:00
powerpc: Use get_signal() signal_setup_done()
2014-08-06 13:03:09 +02:00
all arches, signal: move restart_block to struct task_struct
2015-02-12 18:54:12 -08:00
all arches, signal: move restart_block to struct task_struct
2015-02-12 18:54:12 -08:00
powerpc: Delete non-required instances of include <linux/init.h>
2014-01-15 13:46:44 +11:00
powerpc/smp: Wait until secondaries are active & online
2015-03-04 13:19:33 +11:00
powerpc: Rename __get_SP() to current_stack_pointer()
2014-10-15 11:23:20 +11:00
nosave: consolidate __nosave_{begin,end} in <asm/sections.h>
2014-10-09 22:26:04 -04:00
Disintegrate asm/system.h for PowerPC
2012-03-28 18:30:02 +01:00
Disintegrate asm/system.h for PowerPC
2012-03-28 18:30:02 +01:00
powerpc: Only save/restore SDR1 if in hypervisor mode
2013-10-31 12:37:29 +11:00
powerpc/fsl-booke: Use SPRN_SPRGn rather than mfsprg/mtsprg
2014-01-07 19:06:03 -06:00
unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE
2013-05-09 13:46:38 -04:00
powerpc: Add a proper syscall for switching endianness
2015-03-28 22:03:40 +11:00
powerpc/dscr: Add some in-code documentation
2015-06-07 19:29:15 +10:00
powerpc: Add a proper syscall for switching endianness
2015-03-28 22:03:40 +11:00
powerpc: Add a proper syscall for switching endianness
2015-03-28 22:03:40 +11:00
powerpc: use device_initcall for registering rtc devices
2015-06-16 14:12:29 -04:00
powerpc/kernel: Rename PACA_DSCR to PACA_DSCR_DEFAULT
2015-06-07 19:29:00 +10:00
powerpc: Set the correct kernel taint on machine check errors.
2015-07-06 20:24:35 +10:00
powerpc: Remove the celleb support
2015-04-07 17:15:13 +10:00
powerpc: Fix bad NULL pointer check in udbg_uart_getc_poll()
2014-11-12 13:47:20 +11:00
uprobes/powerpc: Kill arch_uprobe->ainsn
2013-11-20 16:31:01 +01:00
powerpc/vdso: Disable building the 32-bit VDSO on little endian
2015-05-11 20:01:02 +10:00
powerpc: Put FP/VSX and VR state into structures
2013-10-11 17:26:49 +11:00
powerpc: Change vrX register defines to vX to match gcc and glibc
2015-03-16 18:32:11 +11:00
powerpc: use for_each_sg()
2015-06-24 17:49:38 -07:00
powerpc: Align TOC to 256 bytes
2015-05-14 16:59:21 +10:00
b32aadc1a8