Commit Graph

21912 Commits

Author SHA1 Message Date
Kajol Jain 1a8f0886a6 powerpc/perf/hv-24x7: Add cpu hotplug support
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
2020-07-16 13:12:41 +10:00
Nathan Lynch e978a3ccaa powerpc/pseries: remove obsolete memory hotplug DT notifier code
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
2020-07-16 13:12:41 +10:00
Nathan Lynch 38c392cef1 powerpc/pseries: remove dlpar_cpu_readd()
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
2020-07-16 13:12:40 +10:00
Nathan Lynch 4abe60c644 powerpc/pseries: remove memory "re-add" implementation
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
2020-07-16 13:12:40 +10:00
Nathan Lynch bb7c3d36e3 powerpc/pseries: remove prrn special case from DT update path
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
2020-07-16 13:12:39 +10:00
Nathan Lynch cdf082c457 powerpc/numa: remove arch_update_cpu_topology
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
2020-07-16 13:12:39 +10:00
Nathan Lynch 042ef7cc43 powerpc/numa: remove prrn_is_enabled()
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
2020-07-16 13:12:39 +10:00
Nathan Lynch 91713ac377 powerpc/rtasd: simplify handle_rtas_event(), emit message on events
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
2020-07-16 13:12:38 +10:00
Nathan Lynch 1835303e56 powerpc/numa: remove start/stop_topology_update()
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
2020-07-16 13:12:38 +10:00
Nathan Lynch b1815aeac7 powerpc/numa: remove timed_topology_update()
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
2020-07-16 13:12:37 +10:00
Nathan Lynch 893ec6461f powerpc/numa: stub out numa_update_cpu_topology()
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
2020-07-16 13:12:37 +10:00
Nathan Lynch 9fb8b5fd1b powerpc/numa: remove vphn_enabled and prrn_enabled internal flags
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
2020-07-16 13:12:37 +10:00
Nathan Lynch 6325cb4a4e powerpc/numa: remove unreachable topology workqueue code
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
2020-07-16 13:12:36 +10:00
Nathan Lynch 50e0cf3742 powerpc/numa: remove unreachable topology timer code
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
2020-07-16 13:12:36 +10:00
Nathan Lynch e6eacf8eb4 powerpc/numa: make vphn_enabled, prrn_enabled flags const
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
2020-07-16 13:12:36 +10:00
Nathan Lynch 7d35bef96a powerpc/numa: remove unreachable topology update code
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
2020-07-16 13:12:35 +10:00
Nathan Lynch c30f931e89 powerpc/numa: remove ability to enable topology updates
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
2020-07-16 13:12:35 +10:00
Nathan Lynch ec2fc2a9e9 powerpc/rtas: don't online CPUs for partition suspend
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 3aa565f53c ("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 120496ac2d ("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 3aa565f53c ("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 a6717c01dd ("powerpc/rtas: use device model APIs and
    serialization during LPM")
[2] commit 9fb603050f ("powerpc/rtas: retry when cpu offline races
    with suspend/migration")
[3] commit dfd718a2ed ("powerpc/rtas: Fix a potential race between
    CPU-Offline & Migration")

Fixes: 120496ac2d ("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
2020-07-16 13:12:35 +10:00
Nathan Lynch 48f6e7f6d9 powerpc/pseries: remove cede offline state for CPUs
This effectively reverts commit 3aa565f53c ("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: 3aa565f53c ("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
2020-07-16 13:12:34 +10:00
Nicholas Piggin 4d24e21cc6 powerpc/security: Allow for processors that flush the link stack using the 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
2020-07-16 13:12:32 +10:00
Nicholas Piggin 70d7cdaf05 powerpc/64s: Move branch cache flushing bcctr variant to ppc-ops.h
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
2020-07-16 13:12:32 +10:00
Nicholas Piggin c0036549a9 powerpc/security: split branch cache flush toggle from code patching
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
2020-07-16 13:12:32 +10:00
Nicholas Piggin 1afe00c74f powerpc/security: make display of branch cache flush more consistent
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
2020-07-16 13:12:31 +10:00
Nicholas Piggin c06ac27710 powerpc/security: change link stack flush state to the flush type enum
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
2020-07-16 13:12:31 +10:00
Nicholas Piggin 1026798c64 powerpc/security: re-name count cache flush to branch cache flush
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
2020-07-16 13:12:31 +10:00
Nicholas Piggin b2b46304e9 powerpc: re-initialise lazy FPU/VEC counters on every fault
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
2020-07-16 13:00:24 +10:00
Nicholas Piggin 01eb01877f powerpc/64s: Fix restore_math unnecessarily changing MSR
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
2020-07-16 13:00:24 +10:00
Nicholas Piggin 891b4fe8fe powerpc/64s: restore_math remove TM test
The TM test in restore_math added by commit dc16b553c9 ("powerpc:
Always restore FPU/VEC/VSX if hardware transactional memory in use") is
no longer necessary after commit a8318c13e7 ("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
2020-07-16 13:00:24 +10:00
Aneesh Kumar K.V 8c26ab7266 powerpc/pmem: Initialize pmem device on newer hardware
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
2020-07-16 13:00:23 +10:00
Aneesh Kumar K.V 436499ab86 powerpc/pmem: Avoid the barrier in flush routines
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
2020-07-16 13:00:23 +10:00
Aneesh Kumar K.V 76e6c73f33 powerpc/pmem: Update ppc64 to use the new barrier instruction.
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
2020-07-16 13:00:23 +10:00
Aneesh Kumar K.V d358042793 powerpc/pmem: Add flush routines using new pmem store and sync instruction
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
2020-07-16 13:00:22 +10:00
Aneesh Kumar K.V 32db09d992 powerpc/pmem: Add new instructions for persistent storage and sync
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
2020-07-16 13:00:22 +10:00
Aneesh Kumar K.V c83040192f powerpc/pmem: Restrict papr_scm to P8 and above.
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
2020-07-16 13:00:21 +10:00
Nicholas Piggin dd3d9aa558 powerpc/mm/book3s64/radix: Off-load TLB invalidations to host when !GTSE
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
2020-07-16 13:00:21 +10:00
Bharata B Rao b6c8417507 powerpc/pseries: H_REGISTER_PROC_TBL should ask for GTSE only if enabled
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
2020-07-16 13:00:21 +10:00
Bharata B Rao 029ab30b4c powerpc/mm: Enable radix GTSE only if supported.
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
2020-07-16 13:00:21 +10:00
Christophe Leroy 793d74a8c7 powerpc/vdso64: Switch from __get_datapage() to get_datapage inline macro
On the same way as already done on PPC32, drop __get_datapage()
function and use get_datapage inline macro instead.

See commit ec0895f08f ("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
2020-07-15 12:04:40 +10:00
Christophe Leroy 96032f983c powerpc/signal64: Don't opencode page prefaulting
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
2020-07-15 12:04:40 +10:00
Christophe Leroy 020c4831e0 powerpc/signal_32: Simplify loop in PPC64 save_general_regs()
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
2020-07-15 12:04:40 +10:00
Christophe Leroy 667e3c413e powerpc/signal_32: Remove !FULL_REGS() special handling in PPC64 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 965dd3ad30 ("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
2020-07-15 12:04:40 +10:00
Christophe Leroy 41ea93cf7b powerpc/kasan: Fix shadow pages allocation failure
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: 2edb16efc8 ("powerpc/32: Add KASAN support")
Fixes: d2a91cef9b ("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
2020-07-15 12:04:39 +10:00
Christophe Leroy b506923ee4 Revert "powerpc/kasan: Fix shadow pages allocation failure"
This reverts commit d2a91cef9b.

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: d2a91cef9b ("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
2020-07-15 12:04:39 +10:00
Nicholas Piggin 0138ba5783 powerpc/64/signal: Balance return predictor stack in signal trampoline
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
2020-07-15 11:08:27 +10:00
Arnd Bergmann b648a5132c powerpc/spufs: add CONFIG_COREDUMP dependency
The kernel test robot pointed out a slightly different error message
after recent commit 5456ffdee6 ("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
2020-07-15 11:08:27 +10:00
Oliver O'Halloran e3417faec5 powerpc/powernv: Move pnv_ioda_setup_bus_dma under CONFIG_IOMMU_API
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
2020-07-15 11:08:20 +10:00
Oliver O'Halloran 93eacd94e0 powerpc/powernv: Make pnv_pci_sriov_enable() and friends static
The kernel test robot noticed these are non-static which causes Clang to
print some warnings. These are called via ppc_md function pointers so
there's no need for them to be non-static.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200705133557.443607-1-oohall@gmail.com
2020-07-15 11:07:20 +10:00
Srikar Dronamraju a87a77cb94 powerpc/cacheinfo: Add per cpu per index shared_cpu_list
Unlike drivers/base/cacheinfo, powerpc cacheinfo code is not exposing
shared_cpu_list under /sys/devices/system/cpu/cpu<n>/cache/index<m>

Add shared_cpu_list to per cpu per index directory to maintain parity
with x86. Some scripts (example: mmtests
https://github.com/gormanm/mmtests) seem to be looking for
shared_cpu_list instead of shared_cpu_map.

Before this patch:
  # ls /sys/devices/system/cpu0/cache/index1
  coherency_line_size  number_of_sets  size  ways_of_associativity
  level                shared_cpu_map  type
  # cat /sys/devices/system/cpu0/cache/index1/shared_cpu_map
  00ff
  #

After this patch:
  # ls /sys/devices/system/cpu0/cache/index1
  coherency_line_size  number_of_sets   shared_cpu_map  type
  level                shared_cpu_list  size            ways_of_associativity
  # cat /sys/devices/system/cpu0/cache/index1/shared_cpu_map
  00ff
  # cat /sys/devices/system/cpu0/cache/index1/shared_cpu_list
  0-7
  #

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200629103703.4538-4-srikar@linux.vnet.ibm.com
2020-07-15 11:07:20 +10:00
Srikar Dronamraju 74b7492e41 powerpc/cacheinfo: Make cpumap_show code reusable
In anticipation of implementing shared_cpu_list, move code under
shared_cpu_map_show() to a common function.

No functional changes.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200629103703.4538-3-srikar@linux.vnet.ibm.com
2020-07-15 11:07:20 +10:00
Srikar Dronamraju 5658cf085b powerpc/cacheinfo: Use cpumap_print to print cpumap
Tejun Heo had modified shared_cpu_map_show() to use scnprintf instead
of cpumap_print during support for *pb[l] format. Refer commit
0c118b7bd0 ("powerpc: use %*pb[l] to print bitmaps including
cpumasks and nodemasks").

cpumap_print_to_pagebuf() is a standard function to print cpumap. With
commit 9cf79d115f ("bitmap: remove explicit newline handling using
scnprintf format string"), there is no need to print explicit newline
and trailing null character. cpumap_print_to_pagebuf() internally uses
scnprintf(). Hence replace scnprintf() with cpumap_print_to_pagebuf().

Note: shared_cpu_map_show() in drivers/base/cacheinfo.c already uses
cpumap_print_to_pagebuf().

Before this patch:
  # cat /sys/devices/system/cpu0/cache/index1/shared_cpu_map
  00ff

  #

(Notice the extra blank line).

After this patch:
  # cat /sys/devices/system/cpu0/cache/index1/shared_cpu_map
  00ff
  #

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200629103703.4538-2-srikar@linux.vnet.ibm.com
2020-07-15 11:07:19 +10:00