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6c606e57 |
| 18-Nov-2022 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: avoid scheduling in rtas_os_term()
It's unsafe to use rtas_busy_delay() to handle a busy status from the ibm,os-term RTAS function in rtas_os_term():
Kernel panic - not syncing: Attem
powerpc/rtas: avoid scheduling in rtas_os_term()
It's unsafe to use rtas_busy_delay() to handle a busy status from the ibm,os-term RTAS function in rtas_os_term():
Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b BUG: sleeping function called from invalid context at arch/powerpc/kernel/rtas.c:618 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0 preempt_count: 2, expected: 0 CPU: 7 PID: 1 Comm: swapper/0 Tainted: G D 6.0.0-rc5-02182-gf8553a572277-dirty #9 Call Trace: [c000000007b8f000] [c000000001337110] dump_stack_lvl+0xb4/0x110 (unreliable) [c000000007b8f040] [c0000000002440e4] __might_resched+0x394/0x3c0 [c000000007b8f0e0] [c00000000004f680] rtas_busy_delay+0x120/0x1b0 [c000000007b8f100] [c000000000052d04] rtas_os_term+0xb8/0xf4 [c000000007b8f180] [c0000000001150fc] pseries_panic+0x50/0x68 [c000000007b8f1f0] [c000000000036354] ppc_panic_platform_handler+0x34/0x50 [c000000007b8f210] [c0000000002303c4] notifier_call_chain+0xd4/0x1c0 [c000000007b8f2b0] [c0000000002306cc] atomic_notifier_call_chain+0xac/0x1c0 [c000000007b8f2f0] [c0000000001d62b8] panic+0x228/0x4d0 [c000000007b8f390] [c0000000001e573c] do_exit+0x140c/0x1420 [c000000007b8f480] [c0000000001e586c] make_task_dead+0xdc/0x200
Use rtas_busy_delay_time() instead, which signals without side effects whether to attempt the ibm,os-term RTAS call again.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221118150751.469393-5-nathanl@linux.ibm.com
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#
ed2213bf |
| 18-Nov-2022 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: avoid device tree lookups in rtas_os_term()
rtas_os_term() is called during panic. Its behavior depends on a couple of conditions in the /rtas node of the device tree, the traversal of
powerpc/rtas: avoid device tree lookups in rtas_os_term()
rtas_os_term() is called during panic. Its behavior depends on a couple of conditions in the /rtas node of the device tree, the traversal of which entails locking and local IRQ state changes. If the kernel panics while devtree_lock is held, rtas_os_term() as currently written could hang.
Instead of discovering the relevant characteristics at panic time, cache them in file-static variables at boot. Note the lookup for "ibm,extended-os-term" is converted to of_property_read_bool() since it is a boolean property, not an RTAS function token.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> [mpe: Incorporate suggested change from Nick] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221118150751.469393-4-nathanl@linux.ibm.com
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#
336e2554 |
| 18-Nov-2022 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: document rtas_call()
rtas_call() has a complex calling convention, non-standard return values, and many users. Add kernel-doc for it and remove the less structured commentary from rtas
powerpc/rtas: document rtas_call()
rtas_call() has a complex calling convention, non-standard return values, and many users. Add kernel-doc for it and remove the less structured commentary from rtas.h.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221118150751.469393-2-nathanl@linux.ibm.com
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Revision tags: v6.0.9, v5.15.79, v6.0.8, v5.15.78, v6.0.7, v5.15.77, v5.15.76, v6.0.6, v6.0.5, v5.15.75, v6.0.4, v6.0.3, v6.0.2, v5.15.74, v5.15.73, v6.0.1, v5.15.72, v6.0, v5.15.71 |
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#
b8f3e488 |
| 26-Sep-2022 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: block error injection when locked down
The error injection facility on pseries VMs allows corruption of arbitrary guest memory, potentially enabling a sufficiently privileged user to d
powerpc/rtas: block error injection when locked down
The error injection facility on pseries VMs allows corruption of arbitrary guest memory, potentially enabling a sufficiently privileged user to disable lockdown or perform other modifications of the running kernel via the rtas syscall.
Block the PAPR error injection facility from being opened or called when locked down.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Acked-by: Paul Moore <paul@paul-moore.com> (LSM) Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220926131643.146502-3-nathanl@linux.ibm.com
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Revision tags: v5.15.70, v5.15.69, v5.15.68, v5.15.67, v5.15.66 |
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#
f88aabad |
| 07-Sep-2022 |
Nathan Lynch <nathanl@linux.ibm.com> |
Revert "powerpc/rtas: Implement reentrant rtas call"
At the time this was submitted by Leonardo, I confirmed -- or thought I had confirmed -- with PowerVM partition firmware development that the fol
Revert "powerpc/rtas: Implement reentrant rtas call"
At the time this was submitted by Leonardo, I confirmed -- or thought I had confirmed -- with PowerVM partition firmware development that the following RTAS functions:
- ibm,get-xive - ibm,int-off - ibm,int-on - ibm,set-xive
were safe to call on multiple CPUs simultaneously, not only with respect to themselves as indicated by PAPR, but with arbitrary other RTAS calls:
https://lore.kernel.org/linuxppc-dev/875zcy2v8o.fsf@linux.ibm.com/
Recent discussion with firmware development makes it clear that this is not true, and that the code in commit b664db8e3f97 ("powerpc/rtas: Implement reentrant rtas call") is unsafe, likely explaining several strange bugs we've seen in internal testing involving DLPAR and LPM. These scenarios use ibm,configure-connector, whose internal state can be corrupted by the concurrent use of the "reentrant" functions, leading to symptoms like endless busy statuses from RTAS.
Fixes: b664db8e3f97 ("powerpc/rtas: Implement reentrant rtas call") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Laurent Dufour <laurent.dufour@fr.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220907220111.223267-1-nathanl@linux.ibm.com
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Revision tags: v5.15.65, v5.15.64, v5.15.63, v5.15.62, v5.15.61, v5.15.60, v5.15.59, v5.19, v5.15.58, v5.15.57, v5.15.56, v5.15.55, v5.15.54, v5.15.53, v5.15.52, v5.15.51, v5.15.50, v5.15.49, v5.15.48, v5.15.47 |
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#
7bc08056 |
| 14-Jun-2022 |
Andrew Donnellan <ajd@linux.ibm.com> |
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS call through the RTAS filter if the buffer addres
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS call through the RTAS filter if the buffer address is 0.
According to PAPR, ibm,platform-dump is called with a null buffer address to notify the platform firmware that processing of a particular dump is finished.
Without this, on a pseries machine with CONFIG_PPC_RTAS_FILTER enabled, an application such as rtas_errd that is attempting to retrieve a dump will encounter an error at the end of the retrieval process.
Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Reported-by: Sathvika Vasireddy <sathvika@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220614134952.156010-1-ajd@linux.ibm.com
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Revision tags: v5.15.46, v5.15.45, v5.15.44, v5.15.43, v5.15.42, v5.18 |
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#
743cdb7b |
| 19-May-2022 |
Paul Mackerras <paulus@ozlabs.org> |
powerpc/kasan: Mark more real-mode code as not to be instrumented
This marks more files and functions that can possibly be called in real mode as not to be instrumented by KASAN. Most were found by
powerpc/kasan: Mark more real-mode code as not to be instrumented
This marks more files and functions that can possibly be called in real mode as not to be instrumented by KASAN. Most were found by inspection, except for get_pseries_errorlog() which was reported as causing a crash in testing.
Reported-by: Nageswara R Sastry <rnsastry@linux.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/YoX1kZPnmUX4RZEK@cleo
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Revision tags: v5.15.41, v5.15.40, v5.15.39, v5.15.38, v5.15.37, v5.15.36, v5.15.35, v5.15.34, v5.15.33, v5.15.32, v5.15.31, v5.17, v5.15.30, v5.15.29, v5.15.28, v5.15.27 |
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#
804c0a16 |
| 08-Mar-2022 |
Nicholas Piggin <npiggin@gmail.com> |
powerpc/rtas: enture rtas_call is called with MMU enabled
rtas_call must not be called with the MMU disabled because in case of rtas error, log_error is called which requires MMU enabled. Add a test
powerpc/rtas: enture rtas_call is called with MMU enabled
rtas_call must not be called with the MMU disabled because in case of rtas error, log_error is called which requires MMU enabled. Add a test and warning for this.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220308135047.478297-14-npiggin@gmail.com
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#
c5a65e0a |
| 08-Mar-2022 |
Nicholas Piggin <npiggin@gmail.com> |
powerpc/rtas: Call enter_rtas with MSR[EE] disabled
Disable MSR[EE] in C code rather than asm.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
powerpc/rtas: Call enter_rtas with MSR[EE] disabled
Disable MSR[EE] in C code rather than asm.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220308135047.478297-5-npiggin@gmail.com
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#
b6b1c3ce |
| 04-May-2022 |
Laurent Dufour <ldufour@linux.ibm.com> |
powerpc/rtas: Keep MSR[RI] set when calling RTAS
RTAS runs in real mode (MSR[DR] and MSR[IR] unset) and in 32-bit big endian mode (MSR[SF,LE] unset).
The change in MSR is done in enter_rtas() in a
powerpc/rtas: Keep MSR[RI] set when calling RTAS
RTAS runs in real mode (MSR[DR] and MSR[IR] unset) and in 32-bit big endian mode (MSR[SF,LE] unset).
The change in MSR is done in enter_rtas() in a relatively complex way, since the MSR value could be hardcoded.
Furthermore, a panic has been reported when hitting the watchdog interrupt while running in RTAS, this leads to the following stack trace:
watchdog: CPU 24 Hard LOCKUP watchdog: CPU 24 TB:997512652051031, last heartbeat TB:997504470175378 (15980ms ago) ... Supported: No, Unreleased kernel CPU: 24 PID: 87504 Comm: drmgr Kdump: loaded Tainted: G E X 5.14.21-150400.71.1.bz196362_2-default #1 SLE15-SP4 (unreleased) 0d821077ef4faa8dfaf370efb5fdca1fa35f4e2c NIP: 000000001fb41050 LR: 000000001fb4104c CTR: 0000000000000000 REGS: c00000000fc33d60 TRAP: 0100 Tainted: G E X (5.14.21-150400.71.1.bz196362_2-default) MSR: 8000000002981000 <SF,VEC,VSX,ME> CR: 48800002 XER: 20040020 CFAR: 000000000000011c IRQMASK: 1 GPR00: 0000000000000003 ffffffffffffffff 0000000000000001 00000000000050dc GPR04: 000000001ffb6100 0000000000000020 0000000000000001 000000001fb09010 GPR08: 0000000020000000 0000000000000000 0000000000000000 0000000000000000 GPR12: 80040000072a40a8 c00000000ff8b680 0000000000000007 0000000000000034 GPR16: 000000001fbf6e94 000000001fbf6d84 000000001fbd1db0 000000001fb3f008 GPR20: 000000001fb41018 ffffffffffffffff 000000000000017f fffffffffffff68f GPR24: 000000001fb18fe8 000000001fb3e000 000000001fb1adc0 000000001fb1cf40 GPR28: 000000001fb26000 000000001fb460f0 000000001fb17f18 000000001fb17000 NIP [000000001fb41050] 0x1fb41050 LR [000000001fb4104c] 0x1fb4104c Call Trace: Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX Oops: Unrecoverable System Reset, sig: 6 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries ... Supported: No, Unreleased kernel CPU: 24 PID: 87504 Comm: drmgr Kdump: loaded Tainted: G E X 5.14.21-150400.71.1.bz196362_2-default #1 SLE15-SP4 (unreleased) 0d821077ef4faa8dfaf370efb5fdca1fa35f4e2c NIP: 000000001fb41050 LR: 000000001fb4104c CTR: 0000000000000000 REGS: c00000000fc33d60 TRAP: 0100 Tainted: G E X (5.14.21-150400.71.1.bz196362_2-default) MSR: 8000000002981000 <SF,VEC,VSX,ME> CR: 48800002 XER: 20040020 CFAR: 000000000000011c IRQMASK: 1 GPR00: 0000000000000003 ffffffffffffffff 0000000000000001 00000000000050dc GPR04: 000000001ffb6100 0000000000000020 0000000000000001 000000001fb09010 GPR08: 0000000020000000 0000000000000000 0000000000000000 0000000000000000 GPR12: 80040000072a40a8 c00000000ff8b680 0000000000000007 0000000000000034 GPR16: 000000001fbf6e94 000000001fbf6d84 000000001fbd1db0 000000001fb3f008 GPR20: 000000001fb41018 ffffffffffffffff 000000000000017f fffffffffffff68f GPR24: 000000001fb18fe8 000000001fb3e000 000000001fb1adc0 000000001fb1cf40 GPR28: 000000001fb26000 000000001fb460f0 000000001fb17f18 000000001fb17000 NIP [000000001fb41050] 0x1fb41050 LR [000000001fb4104c] 0x1fb4104c Call Trace: Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX ---[ end trace 3ddec07f638c34a2 ]---
This happens because MSR[RI] is unset when entering RTAS but there is no valid reason to not set it here.
RTAS is expected to be called with MSR[RI] as specified in PAPR+ section "7.2.1 Machine State":
R1–7.2.1–9. If called with MSR[RI] equal to 1, then RTAS must protect its own critical regions from recursion by setting the MSR[RI] bit to 0 when in the critical regions.
Fixing this by reviewing the way MSR is compute before calling RTAS. Now a hardcoded value meaning real mode, 32 bits big endian mode and Recoverable Interrupt is loaded. In the case MSR[S] is set, it will remain set while entering RTAS as only urfid can unset it (thanks Fabiano).
In addition a check is added in do_enter_rtas() to detect calls made with MSR[RI] unset, as we are forcing it on later.
This patch has been tested on the following machines: Power KVM Guest P8 S822L (host Ubuntu kernel 5.11.0-49-generic) PowerVM LPAR P8 9119-MME (FW860.A1) p9 9008-22L (FW950.00) P10 9080-HEX (FW1010.00)
Suggested-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220504101244.12107-1-ldufour@linux.ibm.com
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#
e6f6390a |
| 08-Mar-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc: Add missing headers
Don't inherit headers "by chances" from asm/prom.h, asm/mpc52xx.h, asm/pci.h etc...
Include the needed headers, and remove asm/prom.h when it was needed exclusively for
powerpc: Add missing headers
Don't inherit headers "by chances" from asm/prom.h, asm/mpc52xx.h, asm/pci.h etc...
Include the needed headers, and remove asm/prom.h when it was needed exclusively for pulling necessary headers.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/be8bdc934d152a7d8ee8d1a840d5596e2f7d85e0.1646767214.git.christophe.leroy@csgroup.eu
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Revision tags: v5.15.26, v5.15.25, v5.15.24, v5.15.23, v5.15.22, v5.15.21, v5.15.20 |
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#
7c5ed82b |
| 04-Feb-2022 |
Sourabh Jain <sourabhjain@linux.ibm.com> |
powerpc: Set crashkernel offset to mid of RMA region
On large config LPARs (having 192 and more cores), Linux fails to boot due to insufficient memory in the first memblock. It is due to the memory
powerpc: Set crashkernel offset to mid of RMA region
On large config LPARs (having 192 and more cores), Linux fails to boot due to insufficient memory in the first memblock. It is due to the memory reservation for the crash kernel which starts at 128MB offset of the first memblock. This memory reservation for the crash kernel doesn't leave enough space in the first memblock to accommodate other essential system resources.
The crash kernel start address was set to 128MB offset by default to ensure that the crash kernel get some memory below the RMA region which is used to be of size 256MB. But given that the RMA region size can be 512MB or more, setting the crash kernel offset to mid of RMA size will leave enough space for the kernel to allocate memory for other system resources.
Since the above crash kernel offset change is only applicable to the LPAR platform, the LPAR feature detection is pushed before the crash kernel reservation. The rest of LPAR specific initialization will still be done during pseries_probe_fw_features as usual.
This patch is dependent on changes to paca allocation for boot CPU. It expect boot CPU to discover 1T segment support which is introduced by the patch posted here: https://lists.ozlabs.org/pipermail/linuxppc-dev/2022-January/239175.html
Reported-by: Abdul haleem <abdhalee@linux.vnet.ibm.com> Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220204085601.107257-1-sourabhjain@linux.ibm.com
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Revision tags: v5.15.19, v5.15.18, v5.15.17, v5.4.173, v5.15.16, v5.15.15, v5.16, v5.15.10, v5.15.9, v5.15.8, v5.15.7, v5.15.6, v5.15.5, v5.15.4, v5.15.3 |
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#
dd5cde45 |
| 17-Nov-2021 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: rtas_busy_delay_time() kernel-doc
Provide API documentation for rtas_busy_delay_time(), explaining why we return the same value for 9900 and -2.
Signed-off-by: Nathan Lynch <nathanl@l
powerpc/rtas: rtas_busy_delay_time() kernel-doc
Provide API documentation for rtas_busy_delay_time(), explaining why we return the same value for 9900 and -2.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211117060259.957178-3-nathanl@linux.ibm.com
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#
38f7b706 |
| 17-Nov-2021 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: rtas_busy_delay() improvements
Generally RTAS cannot block, and in PAPR it is required to return control to the OS within a few tens of microseconds. In order to support operations whi
powerpc/rtas: rtas_busy_delay() improvements
Generally RTAS cannot block, and in PAPR it is required to return control to the OS within a few tens of microseconds. In order to support operations which may take longer to complete, many RTAS primitives can return intermediate -2 ("busy") or 990x ("extended delay") values, which indicate that the OS should reattempt the same call with the same arguments at some point in the future.
Current versions of PAPR are less than clear about this, but the intended meanings of these values in more detail are:
RTAS_BUSY (-2): RTAS has suspended a potentially long-running operation in order to meet its latency obligation and give the OS the opportunity to perform other work. RTAS can resume making progress as soon as the OS reattempts the call.
RTAS_EXTENDED_DELAY_{MIN...MAX} (9900-9905): RTAS must wait for an external event to occur or for internal contention to resolve before it can complete the requested operation. The value encodes a non-binding hint as to roughly how long the OS should wait before calling again, but the OS is allowed to reattempt the call sooner or even immediately.
Linux of course must take its own CPU scheduling obligations into account when handling these statuses; e.g. a task which receives an RTAS_BUSY status should check whether to reschedule before it attempts the RTAS call again to avoid starving other tasks.
rtas_busy_delay() is a helper function that "consumes" a busy or extended delay status. Common usage:
int rc;
do { rc = rtas_call(rtas_token("some-function"), ...); } while (rtas_busy_delay(rc));
/* convert rc to Linux error value, etc */
If rc is a busy or extended delay status, the caller can rely on rtas_busy_delay() to perform an appropriate sleep or reschedule and return nonzero. Other statuses are handled normally by the caller.
The current implementation of rtas_busy_delay() both oversleeps and overuses the CPU:
* It performs msleep() for all 990x and even when no delay is suggested (-2), but this is understood to actually sleep for two jiffies minimum in practice (20ms with HZ=100). 9900 (1ms) and 9901 (10ms) appear to be the most common extended delay statuses, and the oversleeping measurably lengthens DLPAR operations, which perform many RTAS calls.
* It does not sleep on 990x unless need_resched() is true, causing code like the loop above to needlessly retry, wasting CPU time.
Alter the logic to align better with the intended meanings:
* When passed RTAS_BUSY, perform cond_resched() and return without sleeping. The caller should reattempt immediately
* Always sleep when passed an extended delay status, using usleep_range() for precise shorter sleeps. Limit the sleep time to one second even though there are higher architected values.
Change rtas_busy_delay()'s return type to bool to better reflect its usage, and add kernel-doc.
rtas_busy_delay_time() is unchanged, even though it "incorrectly" returns 1 for RTAS_BUSY. There are users of that API with open-coded delay loops in sensitive contexts that will have to be taken on an individual basis.
Brief results for addition and removal of 5GB memory on a small P9 PowerVM partition follow. Load was generated with stress-ng --cpu N. For add, elapsed time is greatly reduced without significant change in the number of RTAS calls or time spent on CPU. For remove, elapsed time is modestly reduced, with significant reductions in RTAS calls and time spent on CPU.
With no competing workload (- before, + after):
Performance counter stats for 'bash -c echo "memory add count 20" > /sys/kernel/dlpar' (10 runs):
- 1,935 probe:rtas_call # 0.003 M/sec ( +- 0.22% ) - 609.99 msec task-clock # 0.183 CPUs utilized ( +- 0.19% ) + 1,956 probe:rtas_call # 0.003 M/sec ( +- 0.17% ) + 618.56 msec task-clock # 0.278 CPUs utilized ( +- 0.11% )
- 3.3322 +- 0.0670 seconds time elapsed ( +- 2.01% ) + 2.2222 +- 0.0416 seconds time elapsed ( +- 1.87% )
Performance counter stats for 'bash -c echo "memory remove count 20" > /sys/kernel/dlpar' (10 runs):
- 6,224 probe:rtas_call # 0.008 M/sec ( +- 2.57% ) - 750.36 msec task-clock # 0.190 CPUs utilized ( +- 2.01% ) + 843 probe:rtas_call # 0.003 M/sec ( +- 0.12% ) + 250.66 msec task-clock # 0.068 CPUs utilized ( +- 0.17% )
- 3.9394 +- 0.0890 seconds time elapsed ( +- 2.26% ) + 3.678 +- 0.113 seconds time elapsed ( +- 3.07% )
With all CPUs 100% busy (- before, + after):
Performance counter stats for 'bash -c echo "memory add count 20" > /sys/kernel/dlpar' (10 runs):
- 2,979 probe:rtas_call # 0.003 M/sec ( +- 0.12% ) - 1,096.62 msec task-clock # 0.105 CPUs utilized ( +- 0.10% ) + 2,981 probe:rtas_call # 0.003 M/sec ( +- 0.22% ) + 1,095.26 msec task-clock # 0.154 CPUs utilized ( +- 0.21% )
- 10.476 +- 0.104 seconds time elapsed ( +- 1.00% ) + 7.1124 +- 0.0865 seconds time elapsed ( +- 1.22% )
Performance counter stats for 'bash -c echo "memory remove count 20" > /sys/kernel/dlpar' (10 runs):
- 2,702 probe:rtas_call # 0.004 M/sec ( +- 4.00% ) - 722.71 msec task-clock # 0.067 CPUs utilized ( +- 2.41% ) + 1,246 probe:rtas_call # 0.003 M/sec ( +- 0.25% ) + 487.73 msec task-clock # 0.049 CPUs utilized ( +- 0.20% )
- 10.829 +- 0.163 seconds time elapsed ( +- 1.51% ) + 9.9887 +- 0.0866 seconds time elapsed ( +- 0.87% )
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211117060259.957178-2-nathanl@linux.ibm.com
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#
53cadf7d |
| 16-Nov-2021 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: kernel-doc fixes
Fix the following issues reported by kernel-doc:
$ scripts/kernel-doc -v -none arch/powerpc/kernel/rtas.c arch/powerpc/kernel/rtas.c:810: info: Scanning doc for funct
powerpc/rtas: kernel-doc fixes
Fix the following issues reported by kernel-doc:
$ scripts/kernel-doc -v -none arch/powerpc/kernel/rtas.c arch/powerpc/kernel/rtas.c:810: info: Scanning doc for function rtas_activate_firmware arch/powerpc/kernel/rtas.c:818: warning: contents before sections arch/powerpc/kernel/rtas.c:841: info: Scanning doc for function rtas_call_reentrant arch/powerpc/kernel/rtas.c:893: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * Find a specific pseries error log in an RTAS extended event log.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211116215806.928235-1-nathanl@linux.ibm.com
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#
0e3ff69e |
| 07-Sep-2022 |
Nathan Lynch <nathanl@linux.ibm.com> |
Revert "powerpc/rtas: Implement reentrant rtas call"
commit f88aabad33ea22be2ce1c60d8901942e4e2a9edb upstream.
At the time this was submitted by Leonardo, I confirmed -- or thought I had confirmed
Revert "powerpc/rtas: Implement reentrant rtas call"
commit f88aabad33ea22be2ce1c60d8901942e4e2a9edb upstream.
At the time this was submitted by Leonardo, I confirmed -- or thought I had confirmed -- with PowerVM partition firmware development that the following RTAS functions:
- ibm,get-xive - ibm,int-off - ibm,int-on - ibm,set-xive
were safe to call on multiple CPUs simultaneously, not only with respect to themselves as indicated by PAPR, but with arbitrary other RTAS calls:
https://lore.kernel.org/linuxppc-dev/875zcy2v8o.fsf@linux.ibm.com/
Recent discussion with firmware development makes it clear that this is not true, and that the code in commit b664db8e3f97 ("powerpc/rtas: Implement reentrant rtas call") is unsafe, likely explaining several strange bugs we've seen in internal testing involving DLPAR and LPM. These scenarios use ibm,configure-connector, whose internal state can be corrupted by the concurrent use of the "reentrant" functions, leading to symptoms like endless busy statuses from RTAS.
Fixes: b664db8e3f97 ("powerpc/rtas: Implement reentrant rtas call") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Laurent Dufour <laurent.dufour@fr.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220907220111.223267-1-nathanl@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c1cfae46 |
| 14-Jun-2022 |
Andrew Donnellan <ajd@linux.ibm.com> |
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS call through the RTAS filter if the buffer address is 0.
According to PAPR, ibm,platform-dump is called with a null buffer address to notify the platform firmware that processing of a particular dump is finished.
Without this, on a pseries machine with CONFIG_PPC_RTAS_FILTER enabled, an application such as rtas_errd that is attempting to retrieve a dump will encounter an error at the end of the retrieval process.
Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Reported-by: Sathvika Vasireddy <sathvika@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220614134952.156010-1-ajd@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c1cfae46 |
| 14-Jun-2022 |
Andrew Donnellan <ajd@linux.ibm.com> |
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS call through the RTAS filter if the buffer address is 0.
According to PAPR, ibm,platform-dump is called with a null buffer address to notify the platform firmware that processing of a particular dump is finished.
Without this, on a pseries machine with CONFIG_PPC_RTAS_FILTER enabled, an application such as rtas_errd that is attempting to retrieve a dump will encounter an error at the end of the retrieval process.
Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Reported-by: Sathvika Vasireddy <sathvika@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220614134952.156010-1-ajd@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c1cfae46 |
| 14-Jun-2022 |
Andrew Donnellan <ajd@linux.ibm.com> |
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS call through the RTAS filter if the buffer address is 0.
According to PAPR, ibm,platform-dump is called with a null buffer address to notify the platform firmware that processing of a particular dump is finished.
Without this, on a pseries machine with CONFIG_PPC_RTAS_FILTER enabled, an application such as rtas_errd that is attempting to retrieve a dump will encounter an error at the end of the retrieval process.
Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Reported-by: Sathvika Vasireddy <sathvika@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220614134952.156010-1-ajd@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c1cfae46 |
| 14-Jun-2022 |
Andrew Donnellan <ajd@linux.ibm.com> |
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS call through the RTAS filter if the buffer address is 0.
According to PAPR, ibm,platform-dump is called with a null buffer address to notify the platform firmware that processing of a particular dump is finished.
Without this, on a pseries machine with CONFIG_PPC_RTAS_FILTER enabled, an application such as rtas_errd that is attempting to retrieve a dump will encounter an error at the end of the retrieval process.
Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Reported-by: Sathvika Vasireddy <sathvika@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220614134952.156010-1-ajd@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c1cfae46 |
| 14-Jun-2022 |
Andrew Donnellan <ajd@linux.ibm.com> |
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS call through the RTAS filter if the buffer address is 0.
According to PAPR, ibm,platform-dump is called with a null buffer address to notify the platform firmware that processing of a particular dump is finished.
Without this, on a pseries machine with CONFIG_PPC_RTAS_FILTER enabled, an application such as rtas_errd that is attempting to retrieve a dump will encounter an error at the end of the retrieval process.
Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Reported-by: Sathvika Vasireddy <sathvika@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220614134952.156010-1-ajd@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c1cfae46 |
| 14-Jun-2022 |
Andrew Donnellan <ajd@linux.ibm.com> |
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS call through the RTAS filter if the buffer address is 0.
According to PAPR, ibm,platform-dump is called with a null buffer address to notify the platform firmware that processing of a particular dump is finished.
Without this, on a pseries machine with CONFIG_PPC_RTAS_FILTER enabled, an application such as rtas_errd that is attempting to retrieve a dump will encounter an error at the end of the retrieval process.
Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Reported-by: Sathvika Vasireddy <sathvika@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220614134952.156010-1-ajd@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c1cfae46 |
| 14-Jun-2022 |
Andrew Donnellan <ajd@linux.ibm.com> |
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS call through the RTAS filter if the buffer address is 0.
According to PAPR, ibm,platform-dump is called with a null buffer address to notify the platform firmware that processing of a particular dump is finished.
Without this, on a pseries machine with CONFIG_PPC_RTAS_FILTER enabled, an application such as rtas_errd that is attempting to retrieve a dump will encounter an error at the end of the retrieval process.
Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Reported-by: Sathvika Vasireddy <sathvika@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220614134952.156010-1-ajd@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
c1cfae46 |
| 14-Jun-2022 |
Andrew Donnellan <ajd@linux.ibm.com> |
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS call through the RTAS filter if the buffer address is 0.
According to PAPR, ibm,platform-dump is called with a null buffer address to notify the platform firmware that processing of a particular dump is finished.
Without this, on a pseries machine with CONFIG_PPC_RTAS_FILTER enabled, an application such as rtas_errd that is attempting to retrieve a dump will encounter an error at the end of the retrieval process.
Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Reported-by: Sathvika Vasireddy <sathvika@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220614134952.156010-1-ajd@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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|
#
c1cfae46 |
| 14-Jun-2022 |
Andrew Donnellan <ajd@linux.ibm.com> |
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS call through the RTAS filter if the buffer address is 0.
According to PAPR, ibm,platform-dump is called with a null buffer address to notify the platform firmware that processing of a particular dump is finished.
Without this, on a pseries machine with CONFIG_PPC_RTAS_FILTER enabled, an application such as rtas_errd that is attempting to retrieve a dump will encounter an error at the end of the retrieval process.
Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Reported-by: Sathvika Vasireddy <sathvika@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220614134952.156010-1-ajd@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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