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* powerpc/hv-24x7: Add sysfs files inside hv-24x7 device to show cpumaskKajol Jain2020-07-162-0/+15
| | | | | | | | | | | | | | | | | | | Patch here adds a cpumask attr to hv_24x7 pmu along with ABI documentation. Primary use to expose the cpumask is for the perf tool which has the capability to parse the driver sysfs folder and understand the cpumask file. Having cpumask file will reduce the number of perf command line parameters (will avoid "-C" option in the perf tool command line). It can also notify the user which is the current cpu used to retrieve the counter data. command:# cat /sys/devices/hv_24x7/interface/cpumask 0 Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709051836.723765-3-kjain@linux.ibm.com
* powerpc/perf/hv-24x7: Add cpu hotplug supportKajol Jain2020-07-162-0/+47
| | | | | | | | | | | | | | | | | | | Patch here adds cpu hotplug functions to hv_24x7 pmu. A new cpuhp_state "CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE" enum is added. The online callback function updates the cpumask only if its empty. As the primary intention of adding hotplug support is to designate a CPU to make HCALL to collect the counter data. The offline function test and clear corresponding cpu in a cpumask and update cpumask to any other active cpu. Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709051836.723765-2-kjain@linux.ibm.com
* powerpc/pseries: remove obsolete memory hotplug DT notifier codeNathan Lynch2020-07-161-64/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pseries_update_drconf_memory() runs from a DT notifier in response to an update to the ibm,dynamic-memory property of the /ibm,dynamic-reconfiguration-memory node. This property is an older less compact format than the ibm,dynamic-memory-v2 property used in most currently supported firmwares. There has never been an equivalent function for the v2 property. pseries_update_drconf_memory() compares the 'assigned' flag for each LMB in the old vs new properties and adds or removes the block accordingly. However it appears to be of no actual utility: * Partition suspension and PRRNs are specified only to change LMBs' NUMA affinity information. This notifier should be a no-op for those scenarios since the assigned flags should not change. * The memory hotplug/DLPAR path has a hack which short-circuits execution of the notifier: dlpar_memory() ... rtas_hp_event = true; drmem_update_dt() of_update_property() pseries_memory_notifier() pseries_update_drconf_memory() if (rtas_hp_event) return; So this code only makes sense as a relic of the time when more of the DLPAR workflow took place in user space. I don't see a purpose for it now. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-19-nathanl@linux.ibm.com
* powerpc/pseries: remove dlpar_cpu_readd()Nathan Lynch2020-07-162-20/+0
| | | | | | | | dlpar_cpu_readd() is unused now. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-18-nathanl@linux.ibm.com
* powerpc/pseries: remove memory "re-add" implementationNathan Lynch2020-07-162-43/+0
| | | | | | | | | | dlpar_memory() no longer has any callers which pass PSERIES_HP_ELOG_ACTION_READD. Remove this case and the corresponding unreachable code. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-17-nathanl@linux.ibm.com
* powerpc/pseries: remove prrn special case from DT update pathNathan Lynch2020-07-161-27/+0
| | | | | | | | | | | | pseries_devicetree_update() is no longer called with PRRN_SCOPE. The purpose of prrn_update_node() was to remove and then add back a LMB whose NUMA assignment had changed. This has never been reliable, and this codepath has been default-disabled for several releases. Remove prrn_update_node(). Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-16-nathanl@linux.ibm.com
* powerpc/numa: remove arch_update_cpu_topologyNathan Lynch2020-07-162-16/+0
| | | | | | | | | | Since arch_update_cpu_topology() doesn't do anything on powerpc now, remove it and associated dead code. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-15-nathanl@linux.ibm.com
* powerpc/numa: remove prrn_is_enabled()Nathan Lynch2020-07-162-10/+0
| | | | | | | | | All users of this prrn_is_enabled() are gone; remove it. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-14-nathanl@linux.ibm.com
* powerpc/rtasd: simplify handle_rtas_event(), emit message on eventsNathan Lynch2020-07-161-25/+3
| | | | | | | | | | | | | | | | | | prrn_is_enabled() always returns false/0, so handle_rtas_event() can be simplified and some dead code can be removed. Use machine_is() instead of #ifdef to run this code only on pseries, and add an informational ratelimited message that we are ignoring the events. PRRN events are relatively rare in normal operation and usually arise from operator-initiated actions such as a DPO (Dynamic Platform Optimizer) run. Eventually we do want to consume these events and update the device tree, but that needs more care to be safe vs LPM and DLPAR. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-13-nathanl@linux.ibm.com
* powerpc/numa: remove start/stop_topology_update()Nathan Lynch2020-07-164-38/+1
| | | | | | | | | These APIs have become no-ops, so remove them and all call sites. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-12-nathanl@linux.ibm.com
* powerpc/numa: remove timed_topology_update()Nathan Lynch2020-07-163-16/+0
| | | | | | | | | timed_topology_update is a no-op now, so remove it and all call sites. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-11-nathanl@linux.ibm.com
* powerpc/numa: stub out numa_update_cpu_topology()Nathan Lynch2020-07-161-192/+1
| | | | | | | | | | | | | | Previous changes have removed the code which sets bits in cpu_associativity_changes_mask and thus it is never modifed at runtime. From this we can reason that numa_update_cpu_topology() always returns 0 without doing anything. Remove the body of numa_update_cpu_topology() and remove all code which becomes unreachable as a result. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-10-nathanl@linux.ibm.com
* powerpc/numa: remove vphn_enabled and prrn_enabled internal flagsNathan Lynch2020-07-161-4/+2
| | | | | | | | | | These flags are always zero now; remove them and suitably adjust the remaining references to them. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-9-nathanl@linux.ibm.com
* powerpc/numa: remove unreachable topology workqueue codeNathan Lynch2020-07-161-14/+0
| | | | | | | | | | | Since vphn_enabled is always 0, we can remove the call to topology_schedule_update() and remove the code which becomes unreachable as a result. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-8-nathanl@linux.ibm.com
* powerpc/numa: remove unreachable topology timer codeNathan Lynch2020-07-161-21/+0
| | | | | | | | | | Since vphn_enabled is always 0, we can stub out timed_topology_update() and remove the code which becomes unreachable. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-7-nathanl@linux.ibm.com
* powerpc/numa: make vphn_enabled, prrn_enabled flags constNathan Lynch2020-07-161-2/+2
| | | | | | | | | | Previous changes have made it so these flags are never changed; enforce this by making them const. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-6-nathanl@linux.ibm.com
* powerpc/numa: remove unreachable topology update codeNathan Lynch2020-07-161-147/+2
| | | | | | | | | | | | Since the topology_updates_enabled flag is now always false, remove it and the code which has become unreachable. This is the minimum change that prevents 'defined but unused' warnings emitted by the compiler after stubbing out the start/stop_topology_updates() functions. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-5-nathanl@linux.ibm.com
* powerpc/numa: remove ability to enable topology updatesNathan Lynch2020-07-161-70/+1
| | | | | | | | | | | Remove the /proc/powerpc/topology_updates interface and the topology_updates=on/off command line argument. The internal topology_updates_enabled flag remains for now, but always false. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-4-nathanl@linux.ibm.com
* powerpc/rtas: don't online CPUs for partition suspendNathan Lynch2020-07-163-143/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Partition suspension, used for hibernation and migration, requires that the OS place all but one of the LPAR's processor threads into one of two states prior to calling the ibm,suspend-me RTAS function: * the architected offline state (via RTAS stop-self); or * the H_JOIN hcall, which does not return until the partition resumes execution Using H_CEDE as the offline mode, introduced by commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state"), means that any threads which are offline from Linux's point of view must be moved to one of those two states before a partition suspension can proceed. This was eventually addressed in commit 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation"), which added code to temporarily bring up any offline processor threads so they can call H_JOIN. Conceptually this is fine, but the implementation has had multiple races with cpu hotplug operations initiated from user space[1][2][3], the error handling is fragile, and it generates user-visible cpu hotplug events which is a lot of noise for a platform feature that's supposed to minimize disruption to workloads. With commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state") reverted, this code becomes unnecessary, so remove it. Since any offline CPUs now are truly offline from the platform's point of view, it is no longer necessary to bring up CPUs only to have them call H_JOIN and then go offline again upon resuming. Only active threads are required to call H_JOIN; stopped threads can be left alone. [1] commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and serialization during LPM") [2] commit 9fb603050ffd ("powerpc/rtas: retry when cpu offline races with suspend/migration") [3] commit dfd718a2ed1f ("powerpc/rtas: Fix a potential race between CPU-Offline & Migration") Fixes: 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-3-nathanl@linux.ibm.com
* powerpc/pseries: remove cede offline state for CPUsNathan Lynch2020-07-165-229/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This effectively reverts commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state"), which added an offline mode for CPUs which uses the H_CEDE hcall instead of the architected stop-self RTAS function in order to facilitate "folding" of dedicated mode processors on PowerVM platforms to achieve energy savings. This has been the default offline mode since its introduction. There's nothing about stop-self that would prevent the hypervisor from achieving the energy savings available via H_CEDE, so the original premise of this change appears to be flawed. I also have encountered the claim that the transition to and from ceded state is much faster than stop-self/start-cpu. Certainly we would not want to use stop-self as an *idle* mode. That is what H_CEDE is for. However, this difference is insignificant in the context of Linux CPU hotplug, where the latency of an offline or online operation on current systems is on the order of 100ms, mainly attributable to all the various subsystems' cpuhp callbacks. The cede offline mode also prevents accurate accounting, as discussed before: https://lore.kernel.org/linuxppc-dev/1571740391-3251-1-git-send-email-ego@linux.vnet.ibm.com/ Unconditionally use stop-self to offline processor threads. This is the architected method for offlining CPUs on PAPR systems. The "cede_offline" boot parameter is rendered obsolete. Removing this code enables the removal of the partition suspend code which temporarily onlines all present CPUs. Fixes: 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-2-nathanl@linux.ibm.com
* powerpc/security: Allow for processors that flush the link stack using the ↵Nicholas Piggin2020-07-162-8/+21
| | | | | | | | | | | | special bcctr If both count cache and link stack are to be flushed, and can be flushed with the special bcctr, patch that in directly to the flush/branch nop site. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200609070610.846703-7-npiggin@gmail.com
* powerpc/64s: Move branch cache flushing bcctr variant to ppc-ops.hNicholas Piggin2020-07-162-4/+4
| | | | | | Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200609070610.846703-6-npiggin@gmail.com
* powerpc/security: split branch cache flush toggle from code patchingNicholas Piggin2020-07-161-43/+51
| | | | | | | | | | | | | | Branch cache flushing code patching has inter-dependencies on both the link stack and the count cache flushing state. To make the code clearer and to separate the link stack and count cache handling, split the "toggle" (setting up variables and printing enable/disable) from the code patching. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Always print something, even if the flush is disabled] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200609070610.846703-5-npiggin@gmail.com
* powerpc/security: make display of branch cache flush more consistentNicholas Piggin2020-07-161-4/+4
| | | | | | | | Make the count-cache and link-stack messages look the same Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200609070610.846703-4-npiggin@gmail.com
* powerpc/security: change link stack flush state to the flush type enumNicholas Piggin2020-07-161-5/+5
| | | | | | | | | Prepare to allow for hardware link stack flushing by using the none/sw/hw type, same as the count cache state. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200609070610.846703-3-npiggin@gmail.com
* powerpc/security: re-name count cache flush to branch cache flushNicholas Piggin2020-07-163-24/+23
| | | | | | | | | | The count cache flush mostly refers to both count cache and link stack flushing. As a first step to untangling these a bit, re-name the bits that apply to both. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200609070610.846703-2-npiggin@gmail.com
* powerpc: re-initialise lazy FPU/VEC counters on every faultNicholas Piggin2020-07-162-6/+2
| | | | | | | | | | | | | | | | When a FP/VEC/VSX unavailable fault loads registers and enables the facility in the MSR, re-set the lazy restore counters to 1 rather than incrementing them so every fault gets the same number of restores before the next fault. This probably shouldn't be a practical change because if a lazy counter was non-zero then it should have been restored and would not cause a fault when userspace tries to access it. However the code and comment implies otherwise so that's misleading and unnecessary. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200623234139.2262227-3-npiggin@gmail.com
* powerpc/64s: Fix restore_math unnecessarily changing MSRNicholas Piggin2020-07-162-40/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before returning to user, if there are missing FP/VEC/VSX bits from the user MSR then those registers had been saved and must be restored again before use. restore_math will decide whether to restore immediately, or skip the restore and let fp/vec/vsx unavailable faults demand load the registers. Each time restore_math restores one of the FP/VSX or VEC register sets is loaded, an 8-bit counter is incremented (load_fp and load_vec). When these wrap to zero, restore_math no longer restores that register set until after they are next demand faulted. It's quite usual for those counters to have different values, so if one wraps to zero and restore_math no longer restores its registers or user MSR bit but the other is not zero yet does not need to be restored (because the kernel is not frequently using the FPU), then restore_math will be called and it will also not return in the early exit check. This causes msr_check_and_set to test and set the MSR at every kernel exit despite having no work to do. This can cause workloads (e.g., a NULL syscall microbenchmark) to run fast for a time while both counters are non-zero, then slow down when one of the counters reaches zero, then speed up again after the second counter reaches zero. The cost is significant, about 10% slowdown on a NULL syscall benchmark, and the jittery behaviour is very undesirable. Fix this by having restore_math test all conditions first, and only update MSR if we will be loading registers. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200623234139.2262227-2-npiggin@gmail.com
* powerpc/64s: restore_math remove TM testNicholas Piggin2020-07-161-2/+1
| | | | | | | | | | | | The TM test in restore_math added by commit dc16b553c949e ("powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use") is no longer necessary after commit a8318c13e79ba ("powerpc/tm: Fix restoring FP/VMX facility incorrectly on interrupts"), which removed the cases where restore_math has to restore if TM is active. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200623234139.2262227-1-npiggin@gmail.com
* powerpc/pmem: Initialize pmem device on newer hardwareAneesh Kumar K.V2020-07-162-0/+2
| | | | | | | | | | | | | | | | With kernel now supporting new pmem flush/sync instructions, we can now enable the kernel to initialize the device. On P10 these devices would appear with a new compatible string. For PAPR device we have compatible "ibm,pmemory-v2" and for OF pmem device we have compatible "pmem-region-v2" Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200701072235.223558-8-aneesh.kumar@linux.ibm.com
* powerpc/pmem: Avoid the barrier in flush routinesAneesh Kumar K.V2020-07-161-6/+0
| | | | | | | | | nvdimm expect the flush routines to just mark the cache clean. The barrier that mark the store globally visible is done in nvdimm_flush(). Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200701072235.223558-7-aneesh.kumar@linux.ibm.com
* powerpc/pmem: Update ppc64 to use the new barrier instruction.Aneesh Kumar K.V2020-07-161-0/+13
| | | | | | | | | | pmem on POWER10 can now use phwsync instead of hwsync to ensure all previous writes are architecturally visible for the platform buffer flush. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200701072235.223558-6-aneesh.kumar@linux.ibm.com
* libnvdimm/nvdimm/flush: Allow architecture to override the flush barrierAneesh Kumar K.V2020-07-164-5/+29
| | | | | | | | | | | | | | | | | | Architectures like ppc64 provide persistent memory specific barriers that will ensure that all stores for which the modifications are written to persistent storage by preceding dcbfps and dcbstps instructions have updated persistent storage before any data access or data transfer caused by subsequent instructions is initiated. This is in addition to the ordering done by wmb() Update nvdimm core such that architecture can use barriers other than wmb to ensure all previous writes are architecturally visible for the platform buffer flush. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200701072235.223558-5-aneesh.kumar@linux.ibm.com
* powerpc/pmem: Add flush routines using new pmem store and sync instructionAneesh Kumar K.V2020-07-162-4/+47
| | | | | | | | | | | Start using dcbstps; phwsync; sequence for flushing persistent memory range. The new instructions are implemented as a variant of dcbf and hwsync and on P8 and P9 they will be executed as those instructions. We avoid using them on older hardware. This helps to avoid difficult to debug bugs. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200701072235.223558-4-aneesh.kumar@linux.ibm.com
* powerpc/pmem: Add new instructions for persistent storage and syncAneesh Kumar K.V2020-07-161-0/+12
| | | | | | | | | | | | | | | | | | POWER10 introduces two new variants of dcbf instructions (dcbstps and dcbfps) that can be used to write modified locations back to persistent storage. Additionally, POWER10 also introduce phwsync and plwsync which can be used to establish order of these writes to persistent storage. This patch exposes these instructions to the rest of the kernel. The existing dcbf and hwsync instructions in P8 and P9 are adequate to enable appropriate synchronization with OpenCAPI-hosted persistent storage. Hence the new instructions are added as a variant of the old ones that old hardware won't differentiate. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200701072235.223558-3-aneesh.kumar@linux.ibm.com
* powerpc/pmem: Restrict papr_scm to P8 and above.Aneesh Kumar K.V2020-07-161-0/+6
| | | | | | | | | | | | | | | | | | | | | | The PAPR based virtualized persistent memory devices are only supported on POWER9 and above. In the followup patch, the kernel will switch the persistent memory cache flush functions to use a new `dcbf` variant instruction. The new instructions even though added in ISA 3.1 works even on P8 and P9 because these are implemented as a variant of existing `dcbf` and `hwsync` and on P8 and P9 behaves as such. Considering these devices are only supported on P8 and above, update the driver to prevent a P7-compat guest from using persistent memory devices. We don't update of_pmem driver with the same condition, because, on bare-metal, the firmware enables pmem support only on P9 and above. There the kernel depends on OPAL firmware to restrict exposing persistent memory related device tree entries on older hardware. of_pmem.ko is written without any arch dependency and we don't want to add ppc64 specific cpu feature check in of_pmem driver. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200701072235.223558-2-aneesh.kumar@linux.ibm.com
* powerpc/mm/book3s64/radix: Off-load TLB invalidations to host when !GTSENicholas Piggin2020-07-164-8/+175
| | | | | | | | | | | | | When platform doesn't support GTSE, let TLB invalidation requests for radix guests be off-loaded to the host using H_RPT_INVALIDATE hcall. [hcall wrapper, error path handling and renames] Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200703053608.12884-4-bharata@linux.ibm.com
* powerpc/pseries: H_REGISTER_PROC_TBL should ask for GTSE only if enabledBharata B Rao2020-07-161-3/+5
| | | | | | | | | | H_REGISTER_PROC_TBL asks for GTSE by default. GTSE flag bit should be set only when GTSE is supported. Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200703053608.12884-3-bharata@linux.ibm.com
* powerpc/mm: Enable radix GTSE only if supported.Bharata B Rao2020-07-164-6/+17
| | | | | | | | | | | | | | | Make GTSE an MMU feature and enable it by default for radix. However for guest, conditionally enable it if hypervisor supports it via OV5 vector. Let prom_init ask for radix GTSE only if the support exists. Having GTSE as an MMU feature will make it easy to enable radix without GTSE. Currently radix assumes GTSE is enabled by default. Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200703053608.12884-2-bharata@linux.ibm.com
* powerpc/vdso64: Switch from __get_datapage() to get_datapage inline macroChristophe Leroy2020-07-153-34/+12
| | | | | | | | | | | On the same way as already done on PPC32, drop __get_datapage() function and use get_datapage inline macro instead. See commit ec0895f08f99 ("powerpc/vdso32: inline __get_datapage()") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e13d95312e0b9792556b19b4bb8955cc1ff19fc7.1588079622.git.christophe.leroy@c-s.fr
* powerpc/signal64: Don't opencode page prefaultingChristophe Leroy2020-07-151-4/+3
| | | | | | | | | Instead of doing a __get_user() from the first and last location into a tmp var which won't be used, use fault_in_pages_readable() Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/810bd8840ef990a200f58c9dea9abe767ca02a3a.1594146723.git.christophe.leroy@csgroup.eu
* powerpc/signal_32: Simplify loop in PPC64 save_general_regs()Christophe Leroy2020-07-151-10/+8
| | | | | | | | | | | | save_general_regs() which does special handling when i == PT_SOFTE. Rewrite it to minimise the specific part, especially the __put_user() and associated error handling is the same so make it common. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Use a regular if rather than ternary operator] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/47a38df46cae5a5a88a558a64d71f75e9c4d9950.1594125164.git.christophe.leroy@csgroup.eu
* powerpc/signal_32: Remove !FULL_REGS() special handling in PPC64 ↵Christophe Leroy2020-07-151-2/+0
| | | | | | | | | | | | | | | | | | | | | | save_general_regs() Since commit ("1bd79336a426 powerpc: Fix various syscall/signal/swapcontext bugs"), getting save_general_regs() called without FULL_REGS() is very unlikely and generates a warning. The 32-bit version of save_general_regs() doesn't take care of it at all and copies all registers anyway since that commit. Moreover, commit 965dd3ad3076 ("powerpc/64/syscall: Remove non-volatile GPR save optimisation") is another reason why it would never happen. So the same with 64-bit, don't worry about FULL_REGS() and copy all registers all the time. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/173de3b659fa3a5f126a0eb170522cccd909950f.1594125164.git.christophe.leroy@csgroup.eu
* powerpc/kasan: Fix shadow pages allocation failureChristophe Leroy2020-07-151-12/+13
| | | | | | | | | | | | | | | | | Doing kasan pages allocation in MMU_init is too early, kernel doesn't have access yet to the entire memory space and memblock_alloc() fails when the kernel is a bit big. Do it from kasan_init() instead. Fixes: 2edb16efc899 ("powerpc/32: Add KASAN support") Fixes: d2a91cef9bbd ("powerpc/kasan: Fix shadow pages allocation failure") Cc: stable@vger.kernel.org Reported-by: Erhard F. <erhard_f@mailbox.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://bugzilla.kernel.org/show_bug.cgi?id=208181 Link: https://lore.kernel.org/r/63048fcea8a1c02f75429ba3152f80f7853f87fc.1593690707.git.christophe.leroy@csgroup.eu
* Revert "powerpc/kasan: Fix shadow pages allocation failure"Christophe Leroy2020-07-153-3/+5
| | | | | | | | | | | | | | | | | | | | This reverts commit d2a91cef9bbdeb87b7449fdab1a6be6000930210. This commit moved too much work in kasan_init(). The allocation of shadow pages has to be moved for the reason explained in that patch, but the allocation of page tables still need to be done before switching to the final hash table. First revert the incorrect commit, following patch redoes it properly. Fixes: d2a91cef9bbd ("powerpc/kasan: Fix shadow pages allocation failure") Cc: stable@vger.kernel.org Reported-by: Erhard F. <erhard_f@mailbox.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://bugzilla.kernel.org/show_bug.cgi?id=208181 Link: https://lore.kernel.org/r/3667deb0911affbf999b99f87c31c77d5e870cd2.1593690707.git.christophe.leroy@csgroup.eu
* docs: powerpc: Clarify book3s/32 MMU familiesChristophe Leroy2020-07-151-4/+6
| | | | | | | | | | | | | | | | Documentation wrongly tells that book3s/32 CPU have hash MMU. 603 and e300 core only have software loaded TLB. 755, 7450 family and e600 core have both hash MMU and software loaded TLB. This can be selected by setting a bit in HID2 (755) or HID0 (others). At the time being this is not supported by the kernel. Make this explicit in the documentation. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/261923c075d1cb49d02493685e8585d4ea2a5197.1593698951.git.christophe.leroy@csgroup.eu
* selftests/powerpc: Add FPU denormal testNicholas Piggin2020-07-153-1/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a testcase that tries to trigger the FPU denormal exception on Power8 or earlier CPUs. Prior to commit 4557ac6b344b ("powerpc/64s/exception: Fix 0x1500 interrupt handler crash") this would trigger a crash such as: Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: iptable_mangle xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 xt_tcpudp tun bridge stp llc ip6table_filter ip6_tables iptable_filter fuse kvm_hv binfmt_misc squashfs mlx4_ib ib_uverbs dm_multipath scsi_dh_rdac scsi_dh_alua ib_core mlx4_en sr_mod cdrom bnx2x lpfc mlx4_core crc_t10dif scsi_transport_fc sg mdio vmx_crypto crct10dif_vpmsum leds_powernv powernv_rng rng_core led_class powernv_op_panel sunrpc ip_tables x_tables autofs4 CPU: 159 PID: 6854 Comm: fpu_denormal Not tainted 5.8.0-rc2-gcc-8.2.0-00092-g4ec7aaab0828 #192 NIP: c0000000000100ec LR: c00000000001b85c CTR: 0000000000000000 REGS: c000001dd818f770 TRAP: 1500 Not tainted (5.8.0-rc2-gcc-8.2.0-00092-g4ec7aaab0828) MSR: 900000000290b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 24002884 XER: 20000000 CFAR: c00000000001005c IRQMASK: 1 GPR00: c00000000001c4c8 c000001dd818fa00 c00000000171c200 c000001dd8101570 GPR04: 0000000000000000 c000001dd818fe90 c000001dd8101590 000000000000001d GPR08: 0000000000000010 0000000000002000 c000001dd818fe90 fffffffffc48ac60 GPR12: 0000000000002200 c000001ffff4f480 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 00007fffab225b40 0000000000000001 c000000001757168 GPR24: c000001dd8101570 c0000018027b00f0 c000001dd8101570 c000000001496098 GPR28: c00000000174ad05 c000001dd8100000 c000001dd8100000 c000001dd8100000 NIP save_fpu+0xa8/0x2ac LR __giveup_fpu+0x2c/0xd0 Call Trace: 0xc000001dd818fa80 (unreliable) giveup_all+0x118/0x120 __switch_to+0x124/0x6c0 __schedule+0x390/0xaf0 do_task_dead+0x70/0x80 do_exit+0x8fc/0xe10 do_group_exit+0x64/0xd0 sys_exit_group+0x24/0x30 system_call_exception+0x164/0x270 system_call_common+0xf0/0x278 Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Split out of fix patch, add oops log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200708074942.1713396-1-npiggin@gmail.com
* powerpc/64/signal: Balance return predictor stack in signal trampolineNicholas Piggin2020-07-153-18/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Returning from an interrupt or syscall to a signal handler currently begins execution directly at the handler's entry point, with LR set to the address of the sigreturn trampoline. When the signal handler function returns, it runs the trampoline. It looks like this: # interrupt at user address xyz # kernel stuff... signal is raised rfid # void handler(int sig) addis 2,12,.TOC.-.LCF0@ha addi 2,2,.TOC.-.LCF0@l mflr 0 std 0,16(1) stdu 1,-96(1) # handler stuff ld 0,16(1) mtlr 0 blr # __kernel_sigtramp_rt64 addi r1,r1,__SIGNAL_FRAMESIZE li r0,__NR_rt_sigreturn sc # kernel executes rt_sigreturn rfid # back to user address xyz Note the blr with no matching bl. This can corrupt the return predictor. Solve this by instead resuming execution at the signal trampoline which then calls the signal handler. qtrace-tools link_stack checker confirms the entire user/kernel/vdso cycle is balanced after this patch, whereas it's not upstream. Alan confirms the dwarf unwind info still looks good. gdb still recognises the signal frame and can step into parent frames if it break inside a signal handler. Performance is pretty noisy, not a very significant change on a POWER9 here, but branch misses are consistently a lot lower on a microbenchmark: Performance counter stats for './signal': 13,085.72 msec task-clock # 1.000 CPUs utilized 45,024,760,101 cycles # 3.441 GHz 65,102,895,542 instructions # 1.45 insn per cycle 11,271,673,787 branches # 861.372 M/sec 59,468,979 branch-misses # 0.53% of all branches 12,989.09 msec task-clock # 1.000 CPUs utilized 44,692,719,559 cycles # 3.441 GHz 65,109,984,964 instructions # 1.46 insn per cycle 11,282,136,057 branches # 868.585 M/sec 39,786,942 branch-misses # 0.35% of all branches Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200511101952.1463138-1-npiggin@gmail.com
* powerpc/spufs: add CONFIG_COREDUMP dependencyArnd Bergmann2020-07-151-0/+1
| | | | | | | | | | | | | | | | | | | | | The kernel test robot pointed out a slightly different error message after recent commit 5456ffdee666 ("powerpc/spufs: simplify spufs core dumping") to spufs for a configuration that never worked: powerpc64-linux-ld: arch/powerpc/platforms/cell/spufs/file.o: in function `.spufs_proxydma_info_dump': >> file.c:(.text+0x4c68): undefined reference to `.dump_emit' powerpc64-linux-ld: arch/powerpc/platforms/cell/spufs/file.o: in function `.spufs_dma_info_dump': file.c:(.text+0x4d70): undefined reference to `.dump_emit' powerpc64-linux-ld: arch/powerpc/platforms/cell/spufs/file.o: in function `.spufs_wbox_info_dump': file.c:(.text+0x4df4): undefined reference to `.dump_emit' Add a Kconfig dependency to prevent this from happening again. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200706132302.3885935-1-arnd@arndb.de
* powerpc/powernv: Move pnv_ioda_setup_bus_dma under CONFIG_IOMMU_APIOliver O'Halloran2020-07-151-13/+13
| | | | | | | | | | | | | pnv_ioda_setup_bus_dma() is only used when a passed through PE is returned to the host. If the kernel is built without IOMMU support this is dead code. Move it under the #ifdef with the rest of the IOMMU API support. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200705133557.443607-2-oohall@gmail.com
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