linux.git/arch/powerpc/include/asm/opal.h, branch v4.18 Linux kernel source tree powerpc: use time64_t in read_persistent_clock 2018-06-03T10:43:33+00:00 Arnd Bergmann arnd@arndb.de 2018-04-23T08:36:40+00:00 5bfd643583b2e2a203163fd6b617cd9027054200 Looking through the remaining users of the deprecated mktime() function, I found the powerpc rtc handlers, which use it in place of rtc_tm_to_time64(). To clean this up, I'm changing over the read_persistent_clock() function to the read_persistent_clock64() variant, and change all the platform specific handlers along with it. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
Looking through the remaining users of the deprecated mktime()
function, I found the powerpc rtc handlers, which use it in
place of rtc_tm_to_time64().

To clean this up, I'm changing over the read_persistent_clock()
function to the read_persistent_clock64() variant, and change
all the platform specific handlers along with it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powernv: call OPAL_QUIESCE before OPAL_SIGNAL_SYSTEM_RESET 2018-06-03T10:40:30+00:00 Nicholas Piggin npiggin@gmail.com 2018-05-10T12:21:48+00:00 ee03b9b4479d1302d01cebedda3518dc967697b7 Although it is often possible to recover a CPU that was interrupted from OPAL with a system reset NMI, it's undesirable to interrupt them for a few reasons. Firstly because dump/debug code itself needs to call firmware, so it could hang on a lock or possibly corrupt a per-cpu data structure if it or another CPU was interrupted from OPAL. Secondly, the kexec crash dump code will not return from interrupt to unwind the OPAL call. Call OPAL_QUIESCE with QUIESCE_HOLD before sending an NMI IPI to another CPU, which wait for it to leave firmware (or time out) to avoid this problem in normal conditions. Firmware bugs may still result in a timeout and interrupting OPAL, but that is the best option (stops the CPU, and possibly allows firmware to be debugged). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
Although it is often possible to recover a CPU that was interrupted
from OPAL with a system reset NMI, it's undesirable to interrupt them
for a few reasons. Firstly because dump/debug code itself needs to
call firmware, so it could hang on a lock or possibly corrupt a
per-cpu data structure if it or another CPU was interrupted from
OPAL. Secondly, the kexec crash dump code will not return from
interrupt to unwind the OPAL call.

Call OPAL_QUIESCE with QUIESCE_HOLD before sending an NMI IPI to
another CPU, which wait for it to leave firmware (or time out) to
avoid this problem in normal conditions. Firmware bugs may still
result in a timeout and interrupting OPAL, but that is the best
option (stops the CPU, and possibly allows firmware to be debugged).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powernv: opal-sensor: Add support to read 64bit sensor values 2018-05-21T04:48:02+00:00 Shilpasri G Bhat shilpa.bhat@linux.vnet.ibm.com 2018-05-07T10:25:36+00:00 5cdcb01e0af5a709c9bebe0e0450dc0c2f11a4d5 This patch adds support to read 64-bit sensor values. This method is used to read energy sensors and counters which are of type u64. Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
This patch adds support to read 64-bit sensor values. This method is
used to read energy sensors and counters which are of type u64.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powernv: define a standard delay for OPAL_BUSY type retry loops 2018-04-10T14:05:23+00:00 Nicholas Piggin npiggin@gmail.com 2018-04-10T11:49:31+00:00 34dd25de9fe3f60bfdb31b473bf04b28262d0896 This is the start of an effort to tidy up and standardise all the delays. Existing loops have a range of delay/sleep periods from 1ms to 20ms, and some have no delay. They all loop forever except rtc, which times out after 10 retries, and that uses 10ms delays. So use 10ms as our standard delay. The OPAL maintainer agrees 10ms is a reasonable starting point. The idea is to use the same recipe everywhere, once this is proven to work then it will be documented as an OPAL API standard. Then both firmware and OS can agree, and if a particular call needs something else, then that can be documented with reasoning. This is not the end-all of this effort, it's just a relatively easy change that fixes some existing high latency delays. There should be provision for standardising timeouts and/or interruptible loops where possible, so non-fatal firmware errors don't cause hangs. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
This is the start of an effort to tidy up and standardise all the
delays. Existing loops have a range of delay/sleep periods from 1ms
to 20ms, and some have no delay. They all loop forever except rtc,
which times out after 10 retries, and that uses 10ms delays. So use
10ms as our standard delay. The OPAL maintainer agrees 10ms is a
reasonable starting point.

The idea is to use the same recipe everywhere, once this is proven to
work then it will be documented as an OPAL API standard. Then both
firmware and OS can agree, and if a particular call needs something
else, then that can be documented with reasoning.

This is not the end-all of this effort, it's just a relatively easy
change that fixes some existing high latency delays. There should be
provision for standardising timeouts and/or interruptible loops where
possible, so non-fatal firmware errors don't cause hangs.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powernv: Always stop secondaries before reboot/shutdown 2018-04-03T12:59:57+00:00 Nicholas Piggin npiggin@gmail.com 2018-04-01T10:36:15+00:00 f2748bdfe157343eb8cf910a1d89ccf2fd20100b Currently powernv reboot and shutdown requests just leave secondaries to do their own things. This is undesirable because they can trigger any number of watchdogs while waiting for reboot, but also we don't know what else they might be doing -- they might be causing trouble, trampling memory, etc. The opal scheduled flash update code already ran into watchdog problems due to flashing taking a long time, and it was fixed with 2196c6f1ed ("powerpc/powernv: Return secondary CPUs to firmware before FW update"), which returns secondaries to opal. It's been found that regular reboots can take over 10 seconds, which can result in the hard lockup watchdog firing, reboot: Restarting system [ 360.038896709,5] OPAL: Reboot request... Watchdog CPU:0 Hard LOCKUP Watchdog CPU:44 detected Hard LOCKUP other CPUS:16 Watchdog CPU:16 Hard LOCKUP watchdog: BUG: soft lockup - CPU#16 stuck for 3s! [swapper/16:0] This patch removes the special case for flash update, and calls smp_send_stop in all cases before calling reboot/shutdown. smp_send_stop could return CPUs to OPAL, the main reason not to is that the request could come from a NMI that interrupts OPAL code, so re-entry to OPAL can cause a number of problems. Putting secondaries into simple spin loops improves the chances of a successful reboot. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
Currently powernv reboot and shutdown requests just leave secondaries
to do their own things. This is undesirable because they can trigger
any number of watchdogs while waiting for reboot, but also we don't
know what else they might be doing -- they might be causing trouble,
trampling memory, etc.

The opal scheduled flash update code already ran into watchdog problems
due to flashing taking a long time, and it was fixed with 2196c6f1ed
("powerpc/powernv: Return secondary CPUs to firmware before FW update"),
which returns secondaries to opal. It's been found that regular reboots
can take over 10 seconds, which can result in the hard lockup watchdog
firing,

  reboot: Restarting system
  [  360.038896709,5] OPAL: Reboot request...
  Watchdog CPU:0 Hard LOCKUP
  Watchdog CPU:44 detected Hard LOCKUP other CPUS:16
  Watchdog CPU:16 Hard LOCKUP
  watchdog: BUG: soft lockup - CPU#16 stuck for 3s! [swapper/16:0]

This patch removes the special case for flash update, and calls
smp_send_stop in all cases before calling reboot/shutdown.

smp_send_stop could return CPUs to OPAL, the main reason not to is
that the request could come from a NMI that interrupts OPAL code,
so re-entry to OPAL can cause a number of problems. Putting
secondaries into simple spin loops improves the chances of a
successful reboot.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by:  Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powernv: Enable tunneled operations 2018-03-13T04:50:30+00:00 Philippe Bergheaud felix@linux.vnet.ibm.com 2018-03-02T09:56:11+00:00 d6a90bb83b5084829558788ea5b8818c9be3da63 P9 supports PCI tunneled operations (atomics and as_notify). This patch adds support for tunneled operations on powernv, with a new API, to be called by device drivers: pnv_pci_enable_tunnel() Enable tunnel operations, tell driver the 16-bit ASN indication used by kernel. pnv_pci_disable_tunnel() Disable tunnel operations. pnv_pci_set_tunnel_bar() Tell kernel the Tunnel BAR Response address used by driver. This function uses two new OPAL calls, as the PBCQ Tunnel BAR register is configured by skiboot. pnv_pci_get_as_notify_info() Return the ASN info of the thread to be woken up. Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
P9 supports PCI tunneled operations (atomics and as_notify). This
patch adds support for tunneled operations on powernv, with a new
API, to be called by device drivers:

pnv_pci_enable_tunnel()
   Enable tunnel operations, tell driver the 16-bit ASN indication
   used by kernel.

pnv_pci_disable_tunnel()
   Disable tunnel operations.

pnv_pci_set_tunnel_bar()
   Tell kernel the Tunnel BAR Response address used by driver.
   This function uses two new OPAL calls, as the PBCQ Tunnel BAR
   register is configured by skiboot.

pnv_pci_get_as_notify_info()
   Return the ASN info of the thread to be woken up.

Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powernv: Add opal calls for opencapi 2018-01-24T00:42:56+00:00 Frederic Barrat fbarrat@linux.vnet.ibm.com 2018-01-23T11:31:38+00:00 74d656d219b98ef3b96f92439337aa6392a7577d Add opal calls to interact with the NPU: OPAL_NPU_SPA_SETUP: set the Shared Process Area (SPA) The SPA is a table containing one entry (Process Element) per memory context which can be accessed by the opencapi device. OPAL_NPU_SPA_CLEAR_CACHE: clear the context cache The NPU keeps a cache of recently accessed memory contexts. When a Process Element is removed from the SPA, the cache for the link must be cleared. OPAL_NPU_TL_SET: configure the Transaction Layer The Transaction Layer specification defines several templates for messages to be exchanged on the link. During link setup, the host and device must negotiate what templates are supported on both sides and at what rates those messages can be sent. Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
Add opal calls to interact with the NPU:

OPAL_NPU_SPA_SETUP: set the Shared Process Area (SPA)
The SPA is a table containing one entry (Process Element) per memory
context which can be accessed by the opencapi device.

OPAL_NPU_SPA_CLEAR_CACHE: clear the context cache
The NPU keeps a cache of recently accessed memory contexts. When a
Process Element is removed from the SPA, the cache for the link must
be cleared.

OPAL_NPU_TL_SET: configure the Transaction Layer
The Transaction Layer specification defines several templates for
messages to be exchanged on the link. During link setup, the host and
device must negotiate what templates are supported on both sides and
at what rates those messages can be sent.

Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/opal: Add opal_async_wait_response_interruptible() to opal-async 2017-11-06T09:39:28+00:00 Cyril Bur cyrilbur@gmail.com 2017-11-03T02:41:44+00:00 9aab24495c5644b25ced0d11816cc3c061bf74fc This patch adds an _interruptible version of opal_async_wait_response(). This is useful when a long running OPAL call is performed on behalf of a userspace thread, for example, the opal_flash_{read,write,erase} functions performed by the powernv-flash MTD driver. It is foreseeable that these functions would take upwards of two minutes causing the wait_event() to block long enough to cause hung task warnings. Furthermore, wait_event_interruptible() is preferable as otherwise there is no way for signals to stop the process which is going to be confusing in userspace. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
This patch adds an _interruptible version of opal_async_wait_response().
This is useful when a long running OPAL call is performed on behalf of
a userspace thread, for example, the opal_flash_{read,write,erase}
functions performed by the powernv-flash MTD driver.

It is foreseeable that these functions would take upwards of two
minutes causing the wait_event() to block long enough to cause hung
task warnings. Furthermore, wait_event_interruptible() is preferable
as otherwise there is no way for signals to stop the process which is
going to be confusing in userspace.

Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/opal: Make __opal_async_{get, release}_token() static 2017-11-06T09:20:26+00:00 Cyril Bur cyrilbur@gmail.com 2017-11-03T02:41:41+00:00 59cf9a1cfcd9de6392d218fcd69413f2e77babbe There are no callers of both __opal_async_get_token() and __opal_async_release_token(). This patch also removes the possibility of "emergency through synchronous call to __opal_async_get_token()" as such it makes more sense to initialise opal_sync_sem for the maximum number of async tokens. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
There are no callers of both __opal_async_get_token() and
__opal_async_release_token().

This patch also removes the possibility of "emergency through
synchronous call to __opal_async_get_token()" as such it makes more
sense to initialise opal_sync_sem for the maximum number of async
tokens.

Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powernv: Implement NMI IPI with OPAL_SIGNAL_SYSTEM_RESET 2017-10-04T00:27:27+00:00 Nicholas Piggin npiggin@gmail.com 2017-09-29T03:29:42+00:00 e36d0a2ed5019184bb9b94ff1138c87c05905789 This allows MSR[EE]=0 lockups to be detected on an OPAL (bare metal) system similarly to the hcall NMI IPI on pseries guests, when the platform/firmware supports it. This is an example of CPU10 spinning with interrupts hard disabled: Watchdog CPU:32 detected Hard LOCKUP other CPUS:10 Watchdog CPU:10 Hard LOCKUP CPU: 10 PID: 4410 Comm: bash Not tainted 4.13.0-rc7-00074-ge89ce1f89f62-dirty #34 task: c0000003a82b4400 task.stack: c0000003af55c000 NIP: c0000000000a7b38 LR: c000000000659044 CTR: c0000000000a7b00 REGS: c00000000fd23d80 TRAP: 0100 Not tainted (4.13.0-rc7-00074-ge89ce1f89f62-dirty) MSR: 90000000000c1033 <SF,HV,ME,IR,DR,RI,LE> CR: 28422222 XER: 20000000 CFAR: c0000000000a7b38 SOFTE: 0 GPR00: c000000000659044 c0000003af55fbb0 c000000001072a00 0000000000000078 GPR04: c0000003c81b5c80 c0000003c81cc7e8 9000000000009033 0000000000000000 GPR08: 0000000000000000 c0000000000a7b00 0000000000000001 9000000000001003 GPR12: c0000000000a7b00 c00000000fd83200 0000000010180df8 0000000010189e60 GPR16: 0000000010189ed8 0000000010151270 000000001018bd88 000000001018de78 GPR20: 00000000370a0668 0000000000000001 00000000101645e0 0000000010163c10 GPR24: 00007fffd14d6294 00007fffd14d6290 c000000000fba6f0 0000000000000004 GPR28: c000000000f351d8 0000000000000078 c000000000f4095c 0000000000000000 NIP [c0000000000a7b38] sysrq_handle_xmon+0x38/0x40 LR [c000000000659044] __handle_sysrq+0xe4/0x270 Call Trace: [c0000003af55fbd0] [c000000000659044] __handle_sysrq+0xe4/0x270 [c0000003af55fc70] [c000000000659810] write_sysrq_trigger+0x70/0xa0 [c0000003af55fca0] [c0000000003da650] proc_reg_write+0xb0/0x110 [c0000003af55fcf0] [c0000000003423bc] __vfs_write+0x6c/0x1b0 [c0000003af55fd90] [c000000000344398] vfs_write+0xd8/0x240 [c0000003af55fde0] [c00000000034632c] SyS_write+0x6c/0x110 [c0000003af55fe30] [c00000000000b220] system_call+0x58/0x6c Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Use kernel types for opal_signal_system_reset()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
This allows MSR[EE]=0 lockups to be detected on an OPAL (bare metal)
system similarly to the hcall NMI IPI on pseries guests, when the
platform/firmware supports it.

This is an example of CPU10 spinning with interrupts hard disabled:

  Watchdog CPU:32 detected Hard LOCKUP other CPUS:10
  Watchdog CPU:10 Hard LOCKUP
  CPU: 10 PID: 4410 Comm: bash Not tainted 4.13.0-rc7-00074-ge89ce1f89f62-dirty #34
  task: c0000003a82b4400 task.stack: c0000003af55c000
  NIP: c0000000000a7b38 LR: c000000000659044 CTR: c0000000000a7b00
  REGS: c00000000fd23d80 TRAP: 0100   Not tainted  (4.13.0-rc7-00074-ge89ce1f89f62-dirty)
  MSR: 90000000000c1033 <SF,HV,ME,IR,DR,RI,LE>
  CR: 28422222  XER: 20000000
  CFAR: c0000000000a7b38 SOFTE: 0
  GPR00: c000000000659044 c0000003af55fbb0 c000000001072a00 0000000000000078
  GPR04: c0000003c81b5c80 c0000003c81cc7e8 9000000000009033 0000000000000000
  GPR08: 0000000000000000 c0000000000a7b00 0000000000000001 9000000000001003
  GPR12: c0000000000a7b00 c00000000fd83200 0000000010180df8 0000000010189e60
  GPR16: 0000000010189ed8 0000000010151270 000000001018bd88 000000001018de78
  GPR20: 00000000370a0668 0000000000000001 00000000101645e0 0000000010163c10
  GPR24: 00007fffd14d6294 00007fffd14d6290 c000000000fba6f0 0000000000000004
  GPR28: c000000000f351d8 0000000000000078 c000000000f4095c 0000000000000000
  NIP [c0000000000a7b38] sysrq_handle_xmon+0x38/0x40
  LR [c000000000659044] __handle_sysrq+0xe4/0x270
  Call Trace:
  [c0000003af55fbd0] [c000000000659044] __handle_sysrq+0xe4/0x270
  [c0000003af55fc70] [c000000000659810] write_sysrq_trigger+0x70/0xa0
  [c0000003af55fca0] [c0000000003da650] proc_reg_write+0xb0/0x110
  [c0000003af55fcf0] [c0000000003423bc] __vfs_write+0x6c/0x1b0
  [c0000003af55fd90] [c000000000344398] vfs_write+0xd8/0x240
  [c0000003af55fde0] [c00000000034632c] SyS_write+0x6c/0x110
  [c0000003af55fe30] [c00000000000b220] system_call+0x58/0x6c

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Use kernel types for opal_signal_system_reset()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>