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* powerpc/vio: Use device_type to detect familyMichael Ellerman2017-08-231-2/+2
| | | | | | | | | | | | | | | | | | Currently in the vio.c code we use a comparision against the parent device node's full path to decide if the device is a PFO or VIO family device. Both the ibm,platform-facilities and vdevice nodes are defined by PAPR, and must have a matching device_type. So instead of using the path we can instead compare the device_type. I've checked Qemu and kvmtool both do this correctly, and all the PowerVM systems I have access to do also. So it seems to be safe. This removes the dependency on full_name, which is being removed upstream. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* Merge branch 'fixes' into nextMichael Ellerman2017-08-2328-127/+373
|\ | | | | | | | | | | There's a non-trivial dependency between some commits we want to put in next and the KVM prefetch work around that went into fixes. So merge fixes into next.
| * powerpc/mm: Ensure cpumask update is orderedBenjamin Herrenschmidt2017-08-183-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no guarantee that the various isync's involved with the context switch will order the update of the CPU mask with the first TLB entry for the new context being loaded by the HW. Be safe here and add a memory barrier to order any subsequent load/store which may bring entries into the TLB. The corresponding barrier on the other side already exists as pte updates use pte_xchg() which uses __cmpxchg_u64 which has a sync after the atomic operation. Cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Add comments in the code] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc: Fix VSX enabling/flushing to also test MSR_FP and MSR_VECBenjamin Herrenschmidt2017-08-161-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | VSX uses a combination of the old vector registers, the old FP registers and new "second halves" of the FP registers. Thus when we need to see the VSX state in the thread struct (flush_vsx_to_thread()) or when we'll use the VSX in the kernel (enable_kernel_vsx()) we need to ensure they are all flushed into the thread struct if either of them is individually enabled. Unfortunately we only tested if the whole VSX was enabled, not if they were individually enabled. Fixes: 72cd7b44bc99 ("powerpc: Uncomment and make enable_kernel_vsx() routine available") Cc: stable@vger.kernel.org # v4.3+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/watchdog: add locking around init/exit functionsNicholas Piggin2017-08-091-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | When CPUs start and stop the watchdog, they manipulate shared data that is normally protected by the lock. Other CPUs can be running concurrently at this time, so it's a good idea to use locking here to be on the safe side. Remove the barrier which is undocumented and didn't do anything. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/watchdog: Fix marking of stuck CPUsNicholas Piggin2017-08-091-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the SMP detector finds other CPUs stuck, it iterates over them and marks them as stuck. This pulls them out of the pending mask and allows the detector to continue with remaining good CPUs (if nmi_watchdog=panic is not enabled). The code to dothat was buggy because when setting a CPU stuck, if the pending mask became empty, it resets it to keep the watchdog running. However the iterator will continue to run over the new pending mask and mark remaining good CPUs sas stuck. Fix this by doing it with cpumask bitwise operations. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/watchdog: Fix final-check recovered caseNicholas Piggin2017-08-091-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | When the watchdog decides to panic, it takes the lock and double checks everything (to avoid races with the CPU being unstuck or panic()ed by something else). The exit label was misplaced and would result in all-CPUs backtrace and watchdog panic even in the case that the condition was found to be resolved. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/watchdog: Moderate touch_nmi_watchdog overheadNicholas Piggin2017-08-091-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some code can go into a tight loop calling touch_nmi_watchdog (e.g., stop_machine CPU hotplug code). This can cause contention on watchdog locks particularly if all CPUs with watchdog enabled are spinning in the loops. Avoid this storm of activity by running the watchdog timer callback from this path if we have exceeded the timer period since it was last run. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/watchdog: Improve watchdog lock primitiveNicholas Piggin2017-08-091-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Hard-disable interrupts before taking the lock, which prevents soft-NMI re-entrancy and therefore can prevent deadlocks. - Use raw_ variants of local_irq_disable to avoid irq debugging. - When the lock is contended, spin at low SMT priority, using loads only, and with interrupts enabled (where possible). Some stalls have been noticed at high loads that go away with improved locking. There should not be so much locking contention in the first place (which is addressed in a subsequent patch), but locking should still be improved. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc: NMI IPI improve lock primitiveNicholas Piggin2017-08-091-3/+3
| | | | | | | | | | | | | | | | | | | | When the NMI IPI lock is contended, spin at low SMT priority, using loads only, and with interrupts enabled (where possible). This improves behaviour under high contention (e.g., a system crash when a number of CPUs are trying to enter the debugger). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/configs: Re-enable HARD/SOFT lockup detectorsMichael Ellerman2017-08-093-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 05a4a9527931 ("kernel/watchdog: split up config options"), CONFIG_LOCKUP_DETECTOR was split into two separate config options, CONFIG_HARDLOCKUP_DETECTOR and CONFIG_SOFTLOCKUP_DETECTOR. Our defconfigs still have CONFIG_LOCKUP_DETECTOR=y, but that is no longer user selectable, and we don't mention the new options, so we end up with none of them enabled. So update the defconfigs to turn on the new SOFT and HARD options, the end result being the same as what we had previously. Fixes: 05a4a9527931 ("kernel/watchdog: split up config options") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/powernv/idle: Disable LOSE_FULL_CONTEXT states when stop-api failsGautham R. Shenoy2017-08-082-3/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, we use the opal call opal_slw_set_reg() to inform the Sleep-Winkle Engine (SLW) to restore the contents of some of the Hypervisor state on wakeup from deep idle states that lose full hypervisor context (characterized by the flag OPAL_PM_LOSE_FULL_CONTEXT). However, the current code has a bug in that if opal_slw_set_reg() fails, we don't disable the use of these deep states (winkle on POWER8, stop4 onwards on POWER9). This patch fixes this bug by ensuring that if programing the sleep-winkle engine to restore the hypervisor states in pnv_save_sprs_for_deep_states() fails, then we exclude such states by clearing the OPAL_PM_LOSE_FULL_CONTEXT flag from supported_cpuidle_states. As a result POWER8 will be prevented from using winkle for CPU-Hotplug, and POWER9 will put the offlined CPUs to the default stop state when available. Further, we ensure in the initialization of the cpuidle-powernv driver to only include those states whose flags are present in supported_cpuidle_states, thereby skipping OPAL_PM_LOSE_FULL_CONTEXT states when they have been disabled due to stop-api failure. Fixes: 1e1601b38e6 ("powerpc/powernv/idle: Restore SPRs for deep idle states via stop API.") Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * Revert "powerpc/64: Avoid restore_math call if possible in syscall exit"Michael Ellerman2017-08-072-46/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit bc4f65e4cf9d6cc43e0e9ba0b8648cf9201cd55f. As reported by Andreas, this commit is causing unrecoverable SLB misses in the system call exit path: Unrecoverable exception 4100 at c00000000000a1ec Oops: Unrecoverable exception, sig: 6 [#1] SMP NR_CPUS=2 PowerMac ... CPU: 0 PID: 18626 Comm: rm Not tainted 4.13.0-rc3 #1 task: c00000018335e080 task.stack: c000000139e50000 NIP: c00000000000a1ec LR: c00000000000a118 CTR: 0000000000000000 REGS: c000000139e53bb0 TRAP: 4100 Not tainted (4.13.0-rc3) MSR: 9000000000001030 <SF,HV,ME,IR,DR> CR: 24000044 XER: 20000000 SOFTE: 1 GPR00: 0000000000000000 c000000139e53e30 c000000000abb500 fffffffffffffffe GPR04: c0000001eb866298 0000000000000000 0000000000000000 c00000018335e080 GPR08: 900000000000d032 0000000000000000 0000000000000002 fffffffffffff001 GPR12: c000000139e50000 c00000000ffff000 00003fffa8c0dca0 00003fffa8c0dc88 GPR16: 0000000010000000 0000000000000001 00003fffa8c0eaa0 0000000000000000 GPR20: 00003fffa8c27528 00003fffa8c27b00 0000000000000000 0000000000000000 GPR24: 00003fffa8c0d918 00003ffff1b3efa0 00003fffa8c26d68 0000000000000000 GPR28: 00003fffa8c249e8 00003fffa8c263d0 00003fffa8c27550 00003ffff1b3ef10 NIP [c00000000000a1ec] system_call_exit+0xc0/0x21c LR [c00000000000a118] system_call+0x58/0x6c Call Trace: [c000000139e53e30] [c00000000000a118] system_call+0x58/0x6c (unreliable) Instruction dump: 64a51000 7c6300d0 f8a101a0 4bffff9c 3c000000 60000006 780007c6 64000000 60000000 7c004039 4082001c e8ed0170 <88070b78> 88c70b79 7c003214 2c200000 This is caused by us trying to load THREAD_LOAD_FP with MSR_RI=0, and taking an SLB miss on the thread struct. Reported-by: Andreas Schwab <schwab@linux-m68k.org> Diagnosed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/64: Fix __check_irq_replay missing decrementer interruptNicholas Piggin2017-08-041-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the decrementer wraps again and de-asserts the decrementer exception while hard-disabled, __check_irq_replay() has a test to notice the wrap when interrupts are re-enabled. The decrementer check must be done when clearing the PACA_IRQ_HARD_DIS flag, not when the PACA_IRQ_DEC flag is tested. Previously this worked because the decrementer interrupt was always the first one checked after clearing the hard disable flag, but HMI check was moved ahead of that, which introduced this bug. This can cause a missed decrementer interrupt if we soft-disable interrupts then take an HMI which is recorded in irq_happened, then hard-disable interrupts for > 4s to wrap the decrementer. Fixes: e0e0d6b7390b ("powerpc/64: Replay hypervisor maintenance interrupt first") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/perf: POWER9 PMU stops after idle workaroundNicholas Piggin2017-08-041-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | POWER9 DD2 PMU can stop after a state-loss idle in some conditions. A solution is to set then clear MMCRA[60] after wake from state-loss idle. MMCRA[60] is a non-architected bit, see the user manual for details. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Acked-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/83xx/mpc832x_rdb: fix of_irq_to_resource() error checkSergei Shtylyov2017-08-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | of_irq_to_resource() has recently been fixed to return negative error #'s along with 0 in case of failure, however the Freescale MPC832x RDB board code still only regards 0 as a failure indication -- fix it up. Fixes: 7a4228bbff76 ("of: irq: use of_irq_get() in of_irq_to_resource()") Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Acked-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/64s: Fix stack setup in watchdog soft_nmi_common()Nicholas Piggin2017-07-311-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The watchdog soft-NMI exception stack setup loads a stack pointer twice, which is an obvious error. It ends up using the system reset interrupt (true-NMI) stack, which is also a bug because the watchdog could be preempted by a system reset interrupt that overwrites the NMI stack. Change the soft-NMI to use the "emergency stack". The current kernel stack is not used, because of the longer-term goal to prevent asynchronous stack access using soft-disable. Fixes: 2104180a5369 ("powerpc/64s: implement arch-specific hardlockup watchdog") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * Merge tag 'v4.13-rc1' into fixesMichael Ellerman2017-07-311500-27720/+55875
| |\ | | | | | | | | | | | | | | | | | | | | | The fixes branch is based off a random pre-rc1 commit, because we had some fixes that needed to go in before rc1 was released. However we now need to fix some code that went in after that point, but before rc1, so merge rc1 to get that code into fixes so we can fix it!
| * | powerpc/powernv/pci: Return failure for some uses of dma_set_mask()Alistair Popple2017-07-281-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 8e3f1b1d8255 ("powerpc/powernv/pci: Enable 64-bit devices to access >4GB DMA space") introduced the ability for PCI device drivers to request a DMA mask between 64 and 32 bits and actually get a mask greater than 32-bits. However currently if certain machine configuration dependent conditions are not meet the code silently falls back to a 32-bit mask. This makes it hard for device drivers to detect which mask they actually got. Instead we should return an error when the request could not be fulfilled which allows drivers to either fallback or implement other workarounds as documented in DMA-API-HOWTO.txt. Signed-off-by: Alistair Popple <alistair@popple.id.au> Acked-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/boot: Fix 64-bit boot wrapper build with non-biarch compilerMichael Ellerman2017-07-281-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Historically the boot wrapper was always built 32-bit big endian, even for 64-bit kernels. That was because old firmwares didn't necessarily support booting a 64-bit image. Because of that arch/powerpc/boot/Makefile uses CROSS32CC for compilation. However when we added 64-bit little endian support, we also added support for building the boot wrapper 64-bit. However we kept using CROSS32CC, because in most cases it is just CC and everything works. However if the user doesn't specify CROSS32_COMPILE (which no one ever does AFAIK), and CC is *not* biarch (32/64-bit capable), then CROSS32CC becomes just "gcc". On native systems that is probably OK, but if we're cross building it definitely isn't, leading to eg: gcc ... -m64 -mlittle-endian -mabi=elfv2 ... arch/powerpc/boot/cpm-serial.c gcc: error: unrecognized argument in option ‘-mabi=elfv2’ gcc: error: unrecognized command line option ‘-mlittle-endian’ make: *** [zImage] Error 2 To fix it, stop using CROSS32CC, because we may or may not be building 32-bit. Instead setup a BOOTCC, which defaults to CC, and only use CROSS32_COMPILE if it's set and we're building for 32-bit. Fixes: 147c05168fc8 ("powerpc/boot: Add support for 64bit little endian wrapper") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
| * | powerpc/smp: Call smp_ops->setup_cpu() directly on the boot CPUMichael Ellerman2017-07-281-10/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In smp_cpus_done() we need to call smp_ops->setup_cpu() for the boot CPU, which means it has to run *on* the boot CPU. In the past we ensured it ran on the boot CPU by changing the CPU affinity mask of current directly. That was removed in commit 6d11b87d55eb ("powerpc/smp: Replace open coded task affinity logic"), and replaced with a work queue call. Unfortunately using a work queue leads to a lockdep warning, now that the CPU hotplug lock is a regular semaphore: ====================================================== WARNING: possible circular locking dependency detected ... kworker/0:1/971 is trying to acquire lock: (cpu_hotplug_lock.rw_sem){++++++}, at: [<c000000000100974>] apply_workqueue_attrs+0x34/0xa0 but task is already holding lock: ((&wfc.work)){+.+.+.}, at: [<c0000000000fdb2c>] process_one_work+0x25c/0x800 ... CPU0 CPU1 ---- ---- lock((&wfc.work)); lock(cpu_hotplug_lock.rw_sem); lock((&wfc.work)); lock(cpu_hotplug_lock.rw_sem); Although the deadlock can't happen in practice, because smp_cpus_done() only runs in early boot before CPU hotplug is allowed, lockdep can't tell that. Luckily in commit 8fb12156b8db ("init: Pin init task to the boot CPU, initially") tglx changed the generic code to pin init to the boot CPU to begin with. The unpinning of init from the boot CPU happens in sched_init_smp(), which is called after smp_cpus_done(). So smp_cpus_done() is always called on the boot CPU, which means we don't need the work queue call at all - and the lockdep warning goes away. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
| * | powerpc/tm: Fix saving of TM SPRs in core dumpGustavo Romero2017-07-281-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently flush_tmregs_to_thread() does not save the TM SPRs (TFHAR, TFIAR, TEXASR) to the thread struct, unless the process is currently inside a suspended transaction. If the process is core dumping, and the TM SPRs have changed since the last time the process was context switched, then we will save stale values of the TM SPRs to the core dump. Fix it by saving the live register state to the thread struct in that case. Fixes: 08e1c01d6aed ("powerpc/ptrace: Enable support for TM SPR state") Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/mm: Fix pmd/pte_devmap() on non-leaf entriesOliver O'Halloran2017-07-281-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Radix MMU translation tree as defined in ISA v3.0 contains two different types of entry, directories and leaves. Leaves are identified by _PAGE_PTE being set. The formats of the two entries are different, with the directory entries containing no spare bits for use by software. In particular the bit we use for _PAGE_DEVMAP is not reserved for software, and is part of the NLB (Next Level Base) field, essentially the address of the next level in the tree. Note that the Linux pte_t is not == _PAGE_PTE. A huge page pmd entry (or devmap!) is also a leaf and so has _PAGE_PTE set, even though we use a pmd_t for it in Linux. The fix is to ensure that the pmd/pte_devmap() confirm they are looking at a leaf entry (_PAGE_PTE) as well as checking _PAGE_DEVMAP. Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64") Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Tested-by: Laurent Vivier <lvivier@redhat.com> Tested-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com> Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Add a comment in the code and flesh out change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/mm/hash: Free the subpage_prot_table correctlyAneesh Kumar K.V2017-07-271-1/+1
| | | | | | | | | | | | | | | | | | | | | Fixes: dad6f37c2602e ("powerpc: subpage_protect: Increase the array size to take care of 64TB") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Tested-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/Makefile: Fix ld version check with 64-bit LE-only toolchainMichael Ellerman2017-07-261-12/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit efe0160cfd40 ("powerpc/64: Linker on-demand sfpr functions for modules"), we added an ld version check early in the powerpc top-level Makefile. Because the Makefile runs before the kernel config is setup, the checks for CONFIG_CPU_LITTLE_ENDIAN etc. all take the default case. So we end up configuring ld for 32-bit big endian. That would be OK, except that for historical (or perhaps no) reason, we use 'override LD' to add the endian flags to the LD variable itself, rather than the normal approach of adding them to LDFLAGS. The end result is that when we check the ld version we run it as: $(CROSS_COMPILE)ld -EB -m elf32ppc --version This often works, unless you are using a 64-bit only and/or little endian only, toolchain. In which case you see something like: $ make defconfig powerpc64le-linux-ld: unrecognised emulation mode: elf32ppc Supported emulations: elf64lppc elf32lppc elf32lppclinux elf32lppcsim /bin/sh: 1: [: -ge: unexpected operator The proper fix is to stop using 'override LD', but that will require a fair bit of testing. Instead we can fix it for now just by reordering the Makefile to do the version check earlier. Fixes: efe0160cfd40 ("powerpc/64: Linker on-demand sfpr functions for modules") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/pseries: Fix of_node_put() underflow during reconfig removeLaurent Vivier2017-07-261-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As for commit 68baf692c435 ("powerpc/pseries: Fix of_node_put() underflow during DLPAR remove"), the call to of_node_put() must be removed from pSeries_reconfig_remove_node(). dlpar_detach_node() and pSeries_reconfig_remove_node() both call of_detach_node(), and thus the node should not be released in both cases. Fixes: 0829f6d1f69e ("of: device_node kobject lifecycle fixes") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Laurent Vivier <lvivier@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | powerpc/mm/radix: Workaround prefetch issue with KVMBenjamin Herrenschmidt2017-07-266-22/+154
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a somewhat architectural issue with Radix MMU and KVM. When coming out of a guest with AIL (Alternate Interrupt Location, ie, MMU enabled), we start executing hypervisor code with the PID register still containing whatever the guest has been using. The problem is that the CPU can (and will) then start prefetching or speculatively load from whatever host context has that same PID (if any), thus bringing translations for that context into the TLB, which Linux doesn't know about. This can cause stale translations and subsequent crashes. Fixing this in a way that is neither racy nor a huge performance impact is difficult. We could just make the host invalidations always use broadcast forms but that would hurt single threaded programs for example. We chose to fix it instead by partitioning the PID space between guest and host. This is possible because today Linux only use 19 out of the 20 bits of PID space, so existing guests will work if we make the host use the top half of the 20 bits space. We additionally add support for a property to indicate to Linux the size of the PID register which will be useful if we eventually have processors with a larger PID space available. There is still an issue with malicious guests purposefully setting the PID register to a value in the hosts PID range. Hopefully future HW can prevent that, but in the meantime, we handle it with a pair of kludges: - On the way out of a guest, before we clear the current VCPU in the PACA, we check the PID and if it's outside of the permitted range we flush the TLB for that PID. - When context switching, if the mm is "new" on that CPU (the corresponding bit was set for the first time in the mm cpumask), we check if any sibling thread is in KVM (has a non-NULL VCPU pointer in the PACA). If that is the case, we also flush the PID for that CPU (core). This second part is needed to handle the case where a process is migrated (or starts a new pthread) on a sibling thread of the CPU coming out of KVM, as there's a window where stale translations can exist before we detect it and flush them out. A future optimization could be added by keeping track of whether the PID has ever been used and avoid doing that for completely fresh PIDs. We could similarily mark PIDs that have been the subject of a global invalidation as "fresh". But for now this will do. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Rework the asm to build with CONFIG_PPC_RADIX_MMU=n, drop unneeded include of kvm_book3s_asm.h] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | macintosh/rack-meter: Make of_device_ids constArvind Yadav2017-08-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | of_device_ids are not supposed to change at runtime. All functions working with of_device_ids provided by <linux/of.h> work with const of_device_ids. So mark the non-const structs as const. File size before: text data bss dec hex filename 407 576 0 983 3d7 drivers/macintosh/rack-meter.o File size after constify rackmeter_match. text data bss dec hex filename 807 176 0 983 3d7 drivers/macintosh/rack-meter.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/mm/cxl: Add the fault handling cpu to mm cpumaskAneesh Kumar K.V2017-08-172-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We use mm cpumask for serializing against lockless page table walk. Anybody who is doing a lockless page table walk is expected to disable irq and only cpus in mm cpumask is expected do the lockless walk. This ensure that a THP split can send IPI to only cpus in the mm cpumask, to make sure there are no parallel lockless page table walk. Add the CAPI fault handling cpu to the mm cpumask so that we can do the lockless page table walk while inserting hash page table entries. Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/mm: Don't send IPI to all cpus on THP updatesAneesh Kumar K.V2017-08-174-9/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we made sure that lockless walk of linux page table is mostly limitted to current task(current->mm->pgdir) we can update the THP update sequence to only send IPI to CPUs on which this task has run. This helps in reducing the IPI overload on systems with large number of CPUs. WRT kvm even though kvm is walking page table with vpc->arch.pgdir, it is done only on secondary CPUs and in that case we have primary CPU added to task's mm cpumask. Sending an IPI to primary will force the secondary to do a vm exit and hence this mm cpumask usage is safe here. WRT CAPI, we still end up walking linux page table with capi context MM. For now the pte lookup serialization sends an IPI to all CPUs in CPI is in use. We can further improve this by adding the CAPI interrupt handling CPU to task mm cpumask. That will be done in a later patch. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | Merge branch 'topic/ppc-kvm' into nextMichael Ellerman2017-08-1713-55/+103
|\ \ \ | | | | | | | | | | | | | | | | | | | | Bring in the commit to rename find_linux_pte_or_hugepte() which touches arch and KVM code, and might need to be merged with the kvmppc tree to avoid conflicts.
| * | | powerpc/mm: Rename find_linux_pte_or_hugepte()Aneesh Kumar K.V2017-08-1713-55/+103
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add newer helpers to make the function usage simpler. It is always recommended to use find_current_mm_pte() for walking the page table. If we cannot use find_current_mm_pte(), it should be documented why the said usage of __find_linux_pte() is safe against a parallel THP split. For now we have KVM code using __find_linux_pte(). This is because kvm code ends up calling __find_linux_pte() in real mode with MSR_EE=0 but with PACA soft_enabled = 1. We may want to fix that later and make sure we keep the MSR_EE and PACA soft_enabled in sync. When we do that we can switch kvm to use find_linux_pte(). Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/bpf: Use memset32() to pre-fill traps in BPF page(s)Naveen N. Rao2017-08-171-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the newly introduced memset32() to pre-fill BPF page(s) with trap instructions. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/string: Implement optimized memset variantsNaveen N. Rao2017-08-172-1/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on Matthew Wilcox's patches for other architectures. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | block/ps3vram: Check return of ps3vram_cache_initGeoff Levand2017-08-171-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cc: Markus Elfring <elfring@users.sourceforge.net> Cc: Jim Paris <jim@jtan.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | block/ps3vram: Delete an error message for a failed memory allocation in ↵Markus Elfring2017-08-171-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ps3vram_cache_init() Omit an extra message for a memory allocation failure in this function. This issue was detected by using the Coccinelle software. Link: http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdf Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Cc: Jim Paris <jim@jtan.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | selftests/powerpc: Improve tm-resched-dscrSam Bobroff2017-08-172-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tm-resched-dscr self test can, in some situations, run for several minutes before being successfully interrupted by the context switch it needs in order to perform the test. This often seems to occur when the test is being run in a virtual machine. Improve the test by running it under eat_cpu() to guarantee contention for the CPU and increase the chance of a context switch. In practice this seems to reduce the test time, in some cases, from more than two minutes to under a second. Also remove the "progress dots" so that if the test does run for a long time, it doesn't produce large amounts of unnecessary output. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/perf: Fix usage of nest_imc_refcMadhavan Srinivasan2017-08-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nest_imc_refc is a reference count struct, used to track number of active perf sessions using the nest units. Currently the code accesses nest_imc_refc using node_id, which is incorrect, the array is indexed by node number. Meaning in the case of sparse node ids we index off the end of the array. Fix it to use get_nest_pmu_ref() which uses the existing per-cpu variable local_nest_imc_refc. Fixes: 885dcd709ba91 ('powerpc/perf: Add nest IMC PMU support') Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> [mpe: Tweak change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc: Add const to bin_attribute structuresBhumika Goyal2017-08-172-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Declare bin_attribute structures as const as they are only passed as an argument to the function sysfs_create_bin_file. This argument is of type const, so declare the structure as const. Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc: Remove more redundant VSX save/testsBenjamin Herrenschmidt2017-08-161-25/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __giveup_vsx/save_vsx are completely equivalent to testing MSR_FP and MSR_VEC and calling the corresponding giveup/save function so just remove the spurious VSX cases. Also add WARN_ONs checking that we never have VSX enabled without the two other. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc: Remove redundant clear of MSR_VSX in __giveup_vsx()Benjamin Herrenschmidt2017-08-161-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __giveup_fpu() already does it and we cannot have MSR_VSX set without having MSR_FP also set. This also adds a warning to check we indeed do Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc: Remove redundant FP/Altivec giveup codeBenjamin Herrenschmidt2017-08-161-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | __giveup_vsx() already calls those two functions. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc: Fix missing newline before {Benjamin Herrenschmidt2017-08-161-1/+2
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/topology: Remove the unused parent_node() macroDou Liyang2017-08-161-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a7be6e5a7f8d ("mm: drop useless local parameters of __register_one_node()") removes the last user of parent_node(). The parent_node() macro in POWERPC platform is unnecessary. Remove it for cleanup. Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/mm/hugetlb: Allow runtime allocation of 16G.Aneesh Kumar K.V2017-08-161-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we have GIGANTIC_PAGE enabled on powerpc, use this for 16G hugepages with hash translation mode. Depending on the total system memory we have, we may be able to allocate 16G hugepages runtime. This also remove the hugetlb setup difference between hash/radix translation mode. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/mm/hugetlb: Add support for reserving gigantic huge pages via kernel ↵Aneesh Kumar K.V2017-08-166-182/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | command line With commit aa888a74977a8 ("hugetlb: support larger than MAX_ORDER") we added support for allocating gigantic hugepages via kernel command line. Switch ppc64 arch specific code to use that. W.r.t FSL support, we now limit our allocation range using BOOTMEM_ALLOC_ACCESSIBLE. We use the kernel command line to do reservation of hugetlb pages on powernv platforms. On pseries hash mmu mode the supported gigantic huge page size is 16GB and that can only be allocated with hypervisor assist. For pseries the command line option doesn't do the allocation. Instead pseries does gigantic hugepage allocation based on hypervisor hint that is specified via "ibm,expected#pages" property of the memory node. Cc: Scott Wood <oss@buserror.net> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | mm/hugetlb: Allow arch to override and call the weak functionAneesh Kumar K.V2017-08-152-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running in guest mode ppc64 supports a different mechanism for hugetlb allocation/reservation. The LPAR management application called HMC can be used to reserve a set of hugepages and we pass the details of reserved pages via device tree to the guest. (more details in htab_dt_scan_hugepage_blocks()) . We do the memblock_reserve of the range and later in the boot sequence, we add the reserved range to huge_boot_pages. But to enable 16G hugetlb on baremetal config (when we are not running as guest) we want to do memblock reservation during boot. Generic code already does this Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/hugetlb: fix page rights verification in gup_hugepte()Christophe Leroy2017-08-154-12/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gup_hugepte() checks if pages are present and readable, and when 'write' is set, also checks if the pages are writable. Initially this was done by checking if _PAGE_PRESENT and _PAGE_READ were set. In addition, _PAGE_WRITE was verified for write accesses. The problem is that we have to handle the three following cases: 1/ The target defines __PAGE_READ and __PAGE_WRITE 2/ The target defines __PAGE_RW 3/ The target defines __PAGE_RO In case 1/, this is obvious In case 2/, __PAGE_READ is defined as 0 and __PAGE_WRITE as __PAGE_RW so it works as well. But in case 3, __PAGE_RW is defined as 0, which means __PAGE_WRITE is 0 and then the test returns true (page writable) in all cases. A first correction was attempted in commit 6b8cb66a6a7cc ("powerpc: Fix usage of _PAGE_RO in hugepage"), but that fix is wrong: instead of checking that the page is writable when write is requested, it checks that the page is NOT writable when write is NOT requested. This patch adds a new pte_read() helper to check whether a page is readable or not. This avoids handling all possible cases in gup_hugepte(). Then gup_hugepte() is modified to use pte_present(), pte_read() and pte_write() instead of the raw flags. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/mm: Simplify __set_fixmap()Christophe Leroy2017-08-152-18/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __set_fixmap() uses __fix_to_virt() then does the boundary checks by it self. Instead, we can use fix_to_virt() which does the verification at build time. For this, we need to use it inline so that GCC can see the real value of idx at buildtime. In the meantime, we remove the 'fixmaps' variable. This variable is set but has never been used from the beginning (commit 2c419bdeca1d9 ("[POWERPC] Port fixmap from x86 and use for kmap_atomic")) Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/mm: declare some local functions staticChristophe Leroy2017-08-153-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_pteptr() and __mapin_ram_chunk() are only used locally, so define them static Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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