summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel
Commit message (Collapse)AuthorAgeFilesLines
...
* | | powerpc/eeh: Reduce use of pci_dn::nodeAlexey Kardashevskiy2017-08-312-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The pci_dn struct caches a OF device node pointer in order to access the "ibm,loc-code" property when EEH is recovering. However, when this happens in eeh_dev_check_failure(), we also have a pci_dev pointer which should have a valid pointer to the device node when pci_dn has one (both pointers are not NULL for physical functions and are NULL for virtual functions). This changes pci_remove_device_node_info() to look for a parent of the node being removed, just like pci_add_device_node_info() does when it references the parent node. This is the first step to get rid of pci_dn::node. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/eeh: Remove unnecessary config_addr from eeh_devAlexey Kardashevskiy2017-08-312-24/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The eeh_dev struct hold a config space address of an associated node and the very same address is also stored in the pci_dn struct which is always present during the eeh_dev lifetime. This uses bus:devfn directly from pci_dn instead of cached and packed config_addr. Since config_addr is made from device's bus:dev.fn, there is no point in keeping it in the debugfs either so remove that too. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/eeh: Remove unnecessary pointer to phb from eeh_devAlexey Kardashevskiy2017-08-314-18/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | The eeh_dev struct already holds a pointer to pci_dn which it does not exist without and pci_dn itself holds the very same pointer so just use it. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/eeh: Reduce to one the number of places where edev is allocatedAlexey Kardashevskiy2017-08-311-11/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arch/powerpc/kernel/eeh_dev.c:57 is the only legit place where edev is allocated; other 2 places allocate it on stack and in the heap for a very short period of time to use eeh_pe_get() as takes edev. This changes eeh_pe_get() to receive required parameters explicitly. This removes unnecessary temporary allocation of edev. This uses the "pe_no" name instead of the "pe_config_addr" name as it actually is a PE number and not a config space address as it seemed. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/pci: Remove unused parameter from add_one_dev_pci_data()Alexey Kardashevskiy2017-08-311-12/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pdev is always NULL, remove it. To make checkpatch.pl happy, this also removes the "out of memory" message. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc: Machine check interrupt is a non-maskable interruptNicholas Piggin2017-08-311-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | Use nmi_enter similarly to system reset interrupts. This uses NMI printk NMI buffers and turns off various debugging facilities that helps avoid tripping on ourselves or other CPUs. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/powernv: Use kernel crash path for machine checksNicholas Piggin2017-08-312-1/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are quite a few machine check exceptions that can be caused by kernel bugs. To make debugging easier, use the kernel crash path in cases of synchronous machine checks that occur in kernel mode, if that would not result in the machine going straight to panic or crash dump. There is a downside here that die()ing the process in kernel mode can still leave the system unstable. panic_on_oops will always force the system to fail-stop, so systems where that behaviour is important will still do the right thing. As a test, when triggering an i-side 0111b error (ifetch from foreign address) in kernel mode process context on POWER9, the kernel currently dies quickly like this: Severe Machine check interrupt [Not recovered] NIP [ffff000000000000]: 0xffff000000000000 Initiator: CPU Error type: Real address [Instruction fetch (foreign)] [ 127.426651616,0] OPAL: Reboot requested due to Platform error. Effective[ 127.426693712,3] OPAL: Reboot requested due to Platform error. address: ffff000000000000 opal: Reboot type 1 not supported Kernel panic - not syncing: PowerNV Unrecovered Machine Check CPU: 56 PID: 4425 Comm: syscall Tainted: G M 4.12.0-rc1-13857-ga4700a261072-dirty #35 Call Trace: [ 128.017988928,4] IPMI: BUG: Dropping ESEL on the floor due to buggy/mising code in OPAL for this BMC Rebooting in 10 seconds.. Trying to free IRQ 496 from IRQ context! After this patch, the process is killed and the kernel continues with this message, which gives enough information to identify the offending branch (i.e., with CFAR): Severe Machine check interrupt [Not recovered] NIP [ffff000000000000]: 0xffff000000000000 Initiator: CPU Error type: Real address [Instruction fetch (foreign)] Effective address: ffff000000000000 Oops: Machine check, sig: 7 [#1] SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 ... CPU: 22 PID: 4436 Comm: syscall Tainted: G M 4.12.0-rc1-13857-ga4700a261072-dirty #36 task: c000000932300000 task.stack: c000000932380000 NIP: ffff000000000000 LR: 00000000217706a4 CTR: ffff000000000000 REGS: c00000000fc8fd80 TRAP: 0200 Tainted: G M (4.12.0-rc1-13857-ga4700a261072-dirty) MSR: 90000000001c1003 <SF,HV,ME,RI,LE> CR: 24000484 XER: 20000000 CFAR: c000000000004c80 DAR: 0000000021770a90 DSISR: 0a000000 SOFTE: 1 GPR00: 0000000000001ebe 00007fffce4818b0 0000000021797f00 0000000000000000 GPR04: 00007fff8007ac24 0000000044000484 0000000000004000 00007fff801405e8 GPR08: 900000000280f033 0000000024000484 0000000000000000 0000000000000030 GPR12: 9000000000001003 00007fff801bc370 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR24: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR28: 00007fff801b0000 0000000000000000 00000000217707a0 00007fffce481918 NIP [ffff000000000000] 0xffff000000000000 LR [00000000217706a4] 0x217706a4 Call Trace: Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc: Do not send system reset request through the oops pathNicholas Piggin2017-08-311-16/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A system reset is a request to crash / debug the system rather than necessarily caused by encountering a BUG. So there is no need to serialize all CPUs behind the die lock, adding taints to all subsequent traces beyond the first, breaking console locks, etc. The system reset is NMI context which has its own printk buffers to prevent output being interleaved. Then it's better to have all secondaries print out their debug as quickly as possible and the primary will flush out all printk buffers during panic(). So remove the 0x100 path from die, and move it into system_reset. Name the crash/dump reasons "System Reset". This gives "not tained" traces when crashing an untainted kernel. It also gives the panic reason as "System Reset" as opposed to "Fatal exception in interrupt" (or "die oops" for fadump). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc: Do not call ppc_md.panic in fadump panic notifierNicholas Piggin2017-08-312-27/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If fadump is not registered, and no other crash or debug handlers are registered, the powerpc panic handler stops the guest before the generic panic code can push out debug information to the console. Currently, system reset injection causes the guest to silently stop. Stop calling ppc_md.panic in the panic notifier. crash_fadump already does rtas_os_term() to terminate the guest if fadump is registered. Remove ppc_md.panic. Move fadump panic notifier into fadump code. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64: Fix watchdog configuration regressionsNicholas Piggin2017-08-312-7/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes a couple more bits of fallout from the new hard lockup watchdog patch. It restores the required hw_nmi_get_sample_period() function for the perf watchdog, and removes some function declarations on 64e that are only defined for 64s. This fixes the 64e build when the hardlockup detector is enabled. It restores the default behaviour of disabling the perf watchdog, and also fixes disabling the 64s watchdog when running as a guest. Fixes: 2104180a53 ("powerpc/64s: implement arch-specific hardlockup watchdog") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s/radix: Do not allocate SLB shadow structuresNicholas Piggin2017-08-311-2/+11
| | | | | | | | | | | | | | | | | | | | | These are unused in radix mode. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s/radix: Remove bolted-SLB address limit for per-cpu stacksNicholas Piggin2017-08-311-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | Radix MMU does not take SLB or TLB interrupts when accessing kernel linear address. Remove this restriction for radix mode. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s: idle POWER9 can execute stop in virtual modeNicholas Piggin2017-08-291-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The hardware can execute stop in any context, and KVM does not require real mode because siblings do not share MMU state. This saves a switch to real-mode when going idle. Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s: Drop no longer used IDLE_STATE_ENTER_SEQNicholas Piggin2017-08-291-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | There are no longer any callers of IDLE_STATE_ENTER_SEQ, all callers use IDLE_STATE_ENTER_SEQ_NORET. So drop the former. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Split out of larger patch, write change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s: POWER9 can execute stop without a sync sequenceNicholas Piggin2017-08-291-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | We don't need to use IDLE_STATE_ENTER_SEQ_NORET on Power9. Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Split out of larger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s: Move IDLE_STATE_ENTER_SEQ[_NORET] into idle_book3s.SNicholas Piggin2017-08-291-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | This macro is only used in idle_book3s.S, move it in there and add a more descriptive comment. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Split out of larger patch and write change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | Merge branch 'topic/ppc-kvm' into nextMichael Ellerman2017-08-291-11/+24
|\ \ \ | | | | | | | | | | | | | | | | Merge Nicks commit to rework the KVM thread management, shared with the KVM tree via the ppc-kvm topic branch.
| * | | KVM: PPC: Book3S HV: POWER9 does not require secondary thread managementNicholas Piggin2017-08-291-11/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | POWER9 CPUs have independent MMU contexts per thread, so KVM does not need to quiesce secondary threads, so the hwthread_req/hwthread_state protocol does not have to be used. So patch it away on POWER9, and patch away the branch from the Linux idle wakeup to kvm_start_guest that is never used. Add a warning and error out of kvmppc_grab_hwthread in case it is ever called on POWER9. This avoids a hwsync in the idle wakeup path on POWER9. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Paul Mackerras <paulus@ozlabs.org> [mpe: Use WARN(...) instead of WARN_ON()/pr_err(...)] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/oops: Line up NIP & MSR with other rowsMichael Ellerman2017-08-281-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is purely cosmetic, but does look nicer IMHO: Before: task: c000000001453400 task.stack: c000000001c6c000 NIP: c000000000a0fbfc LR: c000000000a0fbf4 CTR: c000000000ba6220 REGS: c0000001fffef820 TRAP: 0300 Not tainted (4.13.0-rc6-gcc-6.3.1-00234-g423af27f7d81) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 88088242 XER: 00000000 CFAR: c0000000000b3488 DAR: 0000000000000000 DSISR: 42000000 SOFTE: 0 After: task: c000000001453400 task.stack: c000000001c6c000 NIP: c000000000a0fbfc LR: c000000000a0fbf4 CTR: c000000000ba6220 REGS: c0000001fffef820 TRAP: 0300 Not tainted (4.13.0-rc6-gcc-6.3.1-00234-g423af27f7d81-dirty) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 88088242 XER: 00000000 CFAR: c0000000000b34a4 DAR: 0000000000000000 DSISR: 42000000 SOFTE: 0 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/oops: Print CR/XER on same line as MSRMichael Ellerman2017-08-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Somehow we missed this when the pr_cont() changes went in. Fix CR/XER to go on the same line as MSR, as they have historically, eg: MSR: 8000000000009032 <SF,EE,ME,IR,DR,RI> CR: 4804408a XER: 20000000 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/oops: Use IS_ENABLED() for oops markersMichael Ellerman2017-08-281-9/+10
| | | | | | | | | | | | | | | | | | | | | | | | Just because it looks less gross. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/oops: Print the kernel's endian in the oopsMichael Ellerman2017-08-281-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Although the MSR tells you what endian you're in it's possible that isn't the same endian the kernel was built for, and if that happens you're usually having a very bad day. So print a marker to make it 100% clear which endian the kernel was built for. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/oops: Fix the oops markers to use pr_cont()Michael Ellerman2017-08-281-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we oops we print a few markers for significant config options such as PREEMPT, SMP etc. Currently these appear on separate lines because we're not using pr_cont() properly. Fix it. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/uprobes: Implement arch_uretprobe_is_alive()Naveen N. Rao2017-08-241-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This helper is used to detect if a uprobe'd function has returned through a setjmp/longjmp, rather than branching to the LR that was updated previously by us. This fixes a SIGSEGV that gets generated when programs use setjmp/longjmp with uretprobes. We use the arm64 model (arch/arm64/kernel/probes/uprobes.c: arch_uretprobe_is_alive()) for detecting when stack frames have been removed from under us. Reference: https://marc.info/?l=linux-kernel&m=143748610330073 commit 7b868e4802a86 ("uprobes/x86: Reimplement arch_uretprobe_is_alive()") commit db087ef69a2b1 ("uprobes/x86: Make arch_uretprobe_is_alive(RP_CHECK_CALL) more clever") Tested with the test program from: https://sourceware.org/git/gitweb.cgi?p=systemtap.git;a=blob;f=testsuite/systemtap.base/bz5274.c;hb=HEAD And this script: $ cat test.sh #!/bin/bash perf probe -x ./bz5274 -a bz5274_main_return=main%return perf probe -x ./bz5274 -a bz5274_funca_return=funca%return perf probe -x ./bz5274 -a bz5274_funcb_return=funcb%return perf probe -x ./bz5274 -a bz5274_funcc_return=funcc%return perf probe -x ./bz5274 -a bz5274_funcd_return=funcd%return perf record -e 'probe_bz5274:*' -aR ./bz5274 Reported-by: Gustavo Luiz Duarte <gduarte@redhat.com> Reported-by: zsun@redhat.com Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | powerpc/kprobes: Don't save/restore DAR/DSISR to/from pt_regs for optprobesNaveen N. Rao2017-08-241-8/+0
| |_|/ |/| | | | | | | | | | | | | | | | | We don't save/restore these across a trap, or with KPROBES_ON_FTRACE. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64: Optimise set/clear of CTRL[RUN] (runlatch)Nicholas Piggin2017-08-231-8/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On modern CPUs the CTRL register is read-only except bit 63 which is the run latch control. This means it can be updated with a mtspr rather than mfspr/mtspr. To accomodate older CPUs (Cell at least), where there are other bits in the register, we still do a read/modify/write on pre 2.06 CPUs. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Update change log to mention 2.06 workaround] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s: Remove spurious IRQ reason in IRQ replayNicholas Piggin2017-08-231-2/+0
| | | | | | | | | | | | | | | | | | | | | HVI interrupts have always used 0x500, so remove the dead branch. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64: Remove redundant instruction in interrupt replayNicholas Piggin2017-08-231-1/+0
| | | | | | | | | | | | | | | Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s: Use the HV handler for external IRQ replay in HV mode on POWER9Nicholas Piggin2017-08-231-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | POWER9 host external interrupts use the h_virt_irq_common handler, so use that to replay them rather than using the hardware_interrupt_common handler. Both call do_IRQ, but using the correct handler reduces i-cache footprint. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s: Merge HV and non-HV paths for doorbell IRQ replayNicholas Piggin2017-08-233-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This results in smaller code, and fewer branches. This relies on the fact that both the 0xe80 and 0xa00 handlers call the same upper level code, namely doorbell_exception(). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Mention we rely on the implementation of the 0xe80/0xa00 handlers] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64: Cleanup __check_irq_replay()Nicholas Piggin2017-08-231-22/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | Move the clearing of irq_happened bits into the condition where they were found to be set. This reduces instruction count slightly, and reduces stores into irq_happened. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s: masked_interrupt() returns to kernel so avoid restoring r13Nicholas Piggin2017-08-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Places in the kernel where r13 is not the PACA pointer must have maskable interrupts disabled, so r13 does not have to be restored when returning from a soft-masked interrupt. We should never have interrupts soft disabled when we're in user space. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s: Optimise clearing of MSR_EE in masked_[H]interrupt()Nicholas Piggin2017-08-231-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | MSR_EE is always enabled in SRR1 for masked interrupts, so we can use xor to clear it. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s: Avoid a branch in masked_[H]interrupt()Nicholas Piggin2017-08-231-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | Interrupts which do not require EE to be cleared can all be tested with a single bitwise test. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc/64s: Fix replay interrupt return label nameMichael Ellerman2017-08-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In __replay_interrupt() we take the address of a local label so we can return to it later. However the assembler turns the local label into a symbol with a name like ".L1^B42" - where "^B" is literally "\002". This does not make for pleasant stack traces. Fix it by giving the label a sensible name. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | powerpc: Convert to using %pOF instead of full_nameRob Herring2017-08-2311-69/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we have a custom printf format specifier, convert users of full_name to use %pOF instead. This is preparation to remove storing of the full path string for each node. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Anatolij Gustschin <agust@denx.de> Cc: Scott Wood <oss@buserror.net> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linuxppc-dev@lists.ozlabs.org Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | Merge branch 'fixes' into nextMichael Ellerman2017-08-238-80/+102
|\ \ \ | | | | | | | | | | | | | | | | | | | | 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: 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>
| * | | 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/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 Ellerman2017-07-318-24/+445
| |\ \ \ | | | |/ | | |/| | | | | | | | | | | | | | | | | | | | | 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/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>
OpenPOWER on IntegriCloud