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fad87dbd |
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22-Feb-2024 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: use correct function name for resetting TCE tables The PAPR spec spells the function name as "ibm,reset-pe-dma-windows" but in practice firmware uses the singular form: "ibm,reset-pe-dma-window" in the device tree. Since we have the wrong spelling in the RTAS function table, reverse lookups (token -> name) fail and warn: unexpected failed lookup for token 86 WARNING: CPU: 1 PID: 545 at arch/powerpc/kernel/rtas.c:659 __do_enter_rtas_trace+0x2a4/0x2b4 CPU: 1 PID: 545 Comm: systemd-udevd Not tainted 6.8.0-rc4 #30 Hardware name: IBM,9105-22A POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NL1060_028) hv:phyp pSeries NIP [c0000000000417f0] __do_enter_rtas_trace+0x2a4/0x2b4 LR [c0000000000417ec] __do_enter_rtas_trace+0x2a0/0x2b4 Call Trace: __do_enter_rtas_trace+0x2a0/0x2b4 (unreliable) rtas_call+0x1f8/0x3e0 enable_ddw.constprop.0+0x4d0/0xc84 dma_iommu_dma_supported+0xe8/0x24c dma_set_mask+0x5c/0xd8 mlx5_pci_init.constprop.0+0xf0/0x46c [mlx5_core] probe_one+0xfc/0x32c [mlx5_core] local_pci_probe+0x68/0x12c pci_call_probe+0x68/0x1ec pci_device_probe+0xbc/0x1a8 really_probe+0x104/0x570 __driver_probe_device+0xb8/0x224 driver_probe_device+0x54/0x130 __driver_attach+0x158/0x2b0 bus_for_each_dev+0xa8/0x120 driver_attach+0x34/0x48 bus_add_driver+0x174/0x304 driver_register+0x8c/0x1c4 __pci_register_driver+0x68/0x7c mlx5_init+0xb8/0x118 [mlx5_core] do_one_initcall+0x60/0x388 do_init_module+0x7c/0x2a4 init_module_from_file+0xb4/0x108 idempotent_init_module+0x184/0x34c sys_finit_module+0x90/0x114 And oopses are possible when lockdep is enabled or the RTAS tracepoints are active, since those paths dereference the result of the lookup. Use the correct spelling to match firmware's behavior, adjusting the related constants to match. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Fixes: 8252b88294d2 ("powerpc/rtas: improve function information lookups") Reported-by: Gaurav Batra <gbatra@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240222-rtas-fix-ibm-reset-pe-dma-window-v1-1-7aaf235ac63c@linux.ibm.com
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#
adf7a019 |
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12-Dec-2023 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: Facilitate high-level call sequences On RTAS platforms there is a general restriction that the OS must not enter RTAS on more than one CPU at a time. This low-level serialization requirement is satisfied by holding a spin lock (rtas_lock) across most RTAS function invocations. However, some pseries RTAS functions require multiple successive calls to complete a logical operation. Beginning a new call sequence for such a function may disrupt any other sequences of that function already in progress. Safe and reliable use of these functions effectively requires higher-level serialization beyond what is already done at the level of RTAS entry and exit. Where a sequence-based RTAS function is invoked only through sys_rtas(), with no in-kernel users, there is no issue as far as the kernel is concerned. User space is responsible for appropriately serializing its call sequences. (Whether user space code actually takes measures to prevent sequence interleaving is another matter.) Examples of such functions currently include ibm,platform-dump and ibm,get-vpd. But where a sequence-based RTAS function has both user space and in-kernel uesrs, there is a hazard. Even if the in-kernel call sites of such a function serialize their sequences correctly, a user of sys_rtas() can invoke the same function at any time, potentially disrupting a sequence in progress. So in order to prevent disruption of kernel-based RTAS call sequences, they must serialize not only with themselves but also with sys_rtas() users, somehow. Preferably without adding more function-specific hacks to sys_rtas(). This is a prerequisite for adding an in-kernel call sequence of ibm,get-vpd, which is in a change to follow. Note that it has never been feasible for the kernel to prevent sys_rtas()-based sequences from being disrupted because control returns to user space on every call. sys_rtas()-based users of these functions have always been, and continue to be, responsible for coordinating their call sequences with other users, even those which may invoke the RTAS functions through less direct means than sys_rtas(). This is an unavoidable consequence of exposing sequence-based RTAS functions through sys_rtas(). * Add an optional mutex member to struct rtas_function. * Statically define a mutex for each RTAS function with known call sequence serialization requirements, and assign its address to the .lock member of the corresponding function table entry, along with justifying commentary. * In sys_rtas(), if the table entry for the RTAS function being called has a populated lock member, acquire it before taking rtas_lock and entering RTAS. * Kernel-based RTAS call sequences are expected to access the appropriate mutex explicitly by name. For example, a user of the ibm,activate-firmware RTAS function would do: int token = rtas_function_token(RTAS_FN_IBM_ACTIVATE_FIRMWARE); int fwrc; mutex_lock(&rtas_ibm_activate_firmware_lock); do { fwrc = rtas_call(token, 0, 1, NULL); } while (rtas_busy_delay(fwrc)); mutex_unlock(&rtas_ibm_activate_firmware_lock); There should be no perceivable change introduced here except that concurrent callers of the same RTAS function via sys_rtas() may block on a mutex instead of spinning on rtas_lock. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-6-e9eafd0c8c6c@linux.ibm.com
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9592aa5a |
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12-Dec-2023 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: Add function return status constants Not all of the generic RTAS function statuses specified in PAPR have symbolic constants and descriptions in rtas.h. Fix this, providing a little more background, slightly updating the existing wording, and improving the formatting. Reviewed-by: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org> Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-4-e9eafd0c8c6c@linux.ibm.com
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646477fc |
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06-Nov-2023 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: Remove 'extern' from function declarations in rtas.h This header occasionally gains new function declarations without the leading extern in accordance with current style rules. Leaving the legacy externs in place is making the header more difficult to read over time because of the inconsistency. Remove them. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> [mpe: Add names to rtas_call() parameters] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231106-rtas-trivial-v1-7-61847655c51f@linux.ibm.com
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19773eda |
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06-Nov-2023 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: Remove trailing space Use scripts/cleanfile to remove instances of trailing space in the core RTAS code and header. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231106-rtas-trivial-v1-6-61847655c51f@linux.ibm.com
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010862d2 |
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06-Nov-2023 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: Move post_mobility_fixup() declaration to pseries This is a pseries-specific function declaration that doesn't belong in rtas.h. Move it to the pseries platform code and adjust pseries/suspend.c accordingly. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231106-rtas-trivial-v1-5-61847655c51f@linux.ibm.com
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#
1d8faf1f |
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06-Nov-2023 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: Remove unused rtas_service_present() rtas_service_present() has no more users. rtas_function_implemented() is now the appropriate API for determining whether a given RTAS function is available to call. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231106-rtas-trivial-v1-4-61847655c51f@linux.ibm.com
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981d1c99 |
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06-Nov-2023 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: Drop declaration of undefined call_rtas() function The call_rtas() function has never been a part of arch/powerpc, and its implementation was removed from arch/ppc by 0a26b1364f14 ("ppc: Remove CHRP, POWER3 and POWER4 support from arch/ppc"). Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231106-rtas-trivial-v1-3-61847655c51f@linux.ibm.com
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e160bf64 |
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18-Aug-2023 |
Mahesh Salgaonkar <mahesh@linux.ibm.com> |
powerpc/rtas: export rtas_error_rc() for reuse. Also, #define descriptive names for common rtas return codes and use it instead of numeric values. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/169235811556.193557.1023625262204809514.stgit@jupiter
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716bfc97 |
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09-Feb-2023 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: introduce rtas_function_token() API Users of rtas_token() supply a string argument that can't be validated at build time. A typo or misspelling has to be caught by inspection or by observing wrong behavior at runtime. Since the core RTAS code now has consolidated the names of all possible RTAS functions and mapped them to their tokens, token lookup can be implemented using symbolic constants to index a static array. So introduce rtas_function_token(), a replacement API which does that, along with a rtas_service_present()-equivalent helper, rtas_function_implemented(). Callers supply an opaque predefined function handle which is used internally to index the function table. Typos or other inappropriate arguments yield build errors, and the function handle is a type that can't be easily confused with RTAS tokens or other integer types. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-19-26929c8cce78@linux.ibm.com
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#
8252b882 |
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09-Feb-2023 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: improve function information lookups The core RTAS support code and its clients perform two types of lookup for RTAS firmware function information. First, mapping a known function name to a token. The typical use case invokes rtas_token() to retrieve the token value to pass to rtas_call(). rtas_token() relies on of_get_property(), which performs a linear search of the /rtas node's property list under a lock with IRQs disabled. Second, and less common: given a token value, looking up some information about the function. The primary example is the sys_rtas filter path, which linearly scans a small table to match the token to a rtas_filter struct. Another use case to come is RTAS entry/exit tracepoints, which will require efficient lookup of function names from token values. Currently there is no general API for this. We need something much like the existing rtas_filters table, but more general and organized to facilitate efficient lookups. Introduce: * A new rtas_function type, aggregating function name, token, and filter. Other function characteristics could be added in the future. * An array of rtas_function, where each element corresponds to a known RTAS function. All information in the table is static save the token values, which are derived from the device tree at boot. The array is sorted by function name to allow binary search. * A named constant for each known RTAS function, used to index the function array. These also will be used in a client-facing API to be added later. * An xarray that maps valid tokens to rtas_function objects. Fold the existing rtas_filter table into the new rtas_function array, with the appropriate adjustments to block_rtas_call(). Remove now-redundant fields from struct rtas_filter. Preserve the function of the CONFIG_CPU_BIG_ENDIAN guard in the current filter table by introducing a per-function flag that is set for the function entries related to pseries LPAR migration. These have never had working users via sys_rtas on ppc64le; see commit de0f7349a0dd ("powerpc/rtas: prevent suspend-related sys_rtas use on LE"). Convert rtas_token() to use a lockless binary search on the function table. Fall back to the old behavior for lookups against names that are not known to be RTAS functions, but issue a warning. rtas_token() is for function names; it is not a general facility for accessing arbitrary properties of the /rtas node. All known misuses of rtas_token() have been converted to more appropriate of_ APIs in preceding changes. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-8-26929c8cce78@linux.ibm.com
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336e2554 |
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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.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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f88aabad |
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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 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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92e6dc25 |
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07-Feb-2022 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/pseries: make pseries_devicetree_update() static pseries_devicetree_update() has only one call site, in the same file in which it is defined. Make it static. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220207221247.354454-1-nathanl@linux.ibm.com
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38f7b706 |
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16-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 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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e5d56763 |
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08-Apr-2021 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: rename RTAS_RMOBUF_MAX to RTAS_USER_REGION_SIZE RTAS_RMOBUF_MAX doesn't actually describe a "maximum" value in any sense. It represents the size of an area of memory set aside for user space to use as work areas for certain RTAS calls. Rename it to RTAS_USER_REGION_SIZE. 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/20210408140630.205502-6-nathanl@linux.ibm.com
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6c6fdbb2 |
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25-Jan-2021 |
Chengyang Fan <cy.fan@huawei.com> |
powerpc: remove unneeded semicolons Remove superfluous semicolons after function definitions. Signed-off-by: Chengyang Fan <cy.fan@huawei.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210125095338.1719405-1-cy.fan@huawei.com
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1b248817 |
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07-Dec-2020 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: remove unused rtas_suspend_last_cpu() rtas_suspend_last_cpu() is now unused, remove it and __rtas_suspend_last_cpu() which also becomes unused. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-24-nathanl@linux.ibm.com
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395b2c09 |
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07-Dec-2020 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: remove rtas_suspend_cpu() rtas_suspend_cpu() no longer has users; remove it and __rtas_suspend_cpu() which now becomes unused as well. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-22-nathanl@linux.ibm.com
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5f6665e4 |
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07-Dec-2020 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: remove rtas_ibm_suspend_me_unsafe() rtas_ibm_suspend_me_unsafe() is now unused; remove it and rtas_percpu_suspend_me() which becomes unused as a result. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-17-nathanl@linux.ibm.com
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4d756894 |
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07-Dec-2020 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: dispatch partition migration requests to pseries sys_rtas() cannot call ibm,suspend-me directly in the same way it handles other inputs. Instead it must dispatch the request to code that can first perform the H_JOIN sequence before any call to ibm,suspend-me can succeed. Over time kernel/rtas.c has accreted a fair amount of platform-specific code to implement this. Since a different, more robust implementation of the suspend sequence is now in the pseries platform code, we want to dispatch the request there. Note that invoking ibm,suspend-me via the RTAS syscall is all but deprecated; this change preserves ABI compatibility for old programs while providing to them the benefit of the new partition suspend implementation. This is a behavior change in that the kernel performs the device tree update and firmware activation before returning, but experimentation indicates this is tolerated fine by legacy user space. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-16-nathanl@linux.ibm.com
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5f485a66 |
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07-Dec-2020 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: add rtas_activate_firmware() Provide a documented wrapper function for the ibm,activate-firmware service, which must be called after a partition migration or hibernation. If the function is absent or the call fails, the OS will continue to run normally with the current firmware, so there is no need to perform any recovery. Just log it and continue. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-6-nathanl@linux.ibm.com
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701ba683 |
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07-Dec-2020 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: add rtas_ibm_suspend_me() Now that the name is available, provide a simple wrapper for ibm,suspend-me which returns both a Linux errno and optionally the actual RTAS status to the caller. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-5-nathanl@linux.ibm.com
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7049b288 |
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07-Dec-2020 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: rtas_ibm_suspend_me -> rtas_ibm_suspend_me_unsafe The pseries partition suspend sequence requires that all active CPUs call H_JOIN, which suspends all but one of them with interrupts disabled. The "chosen" CPU is then to call ibm,suspend-me to complete the suspend. Upon returning from ibm,suspend-me, the chosen CPU is to use H_PROD to wake the joined CPUs. Using on_each_cpu() for this, as rtas_ibm_suspend_me() does to implement partition migration, is susceptible to deadlock with other users of on_each_cpu() and with users of stop_machine APIs. The callback passed to on_each_cpu() is not allowed to synchronize with other CPUs in the way it is used here. Complicating the fix is the fact that rtas_ibm_suspend_me() also occupies the function name that should be used to provide a more conventional wrapper for ibm,suspend-me. Rename rtas_ibm_suspend_me() to rtas_ibm_suspend_me_unsafe() to free up the name and indicate that it should not gain users. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-4-nathanl@linux.ibm.com
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970e453e |
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07-Dec-2020 |
Nathan Lynch <nathanl@linux.ibm.com> |
powerpc/rtas: complete ibm,suspend-me status codes We don't completely account for the possible return codes for ibm,suspend-me. Add definitions for these. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-3-nathanl@linux.ibm.com
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4abe60c6 |
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11-Jun-2020 |
Nathan Lynch <nathanl@linux.ibm.com> |
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
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ec2fc2a9 |
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11-Jun-2020 |
Nathan Lynch <nathanl@linux.ibm.com> |
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 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state"), means that any threads which are offline from Linux's point of view must be moved to one of those two states before a partition suspension can proceed. This was eventually addressed in commit 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation"), which added code to temporarily bring up any offline processor threads so they can call H_JOIN. Conceptually this is fine, but the implementation has had multiple races with cpu hotplug operations initiated from user space[1][2][3], the error handling is fragile, and it generates user-visible cpu hotplug events which is a lot of noise for a platform feature that's supposed to minimize disruption to workloads. With commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state") reverted, this code becomes unnecessary, so remove it. Since any offline CPUs now are truly offline from the platform's point of view, it is no longer necessary to bring up CPUs only to have them call H_JOIN and then go offline again upon resuming. Only active threads are required to call H_JOIN; stopped threads can be left alone. [1] commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and serialization during LPM") [2] commit 9fb603050ffd ("powerpc/rtas: retry when cpu offline races with suspend/migration") [3] commit dfd718a2ed1f ("powerpc/rtas: Fix a potential race between CPU-Offline & Migration") Fixes: 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200612051238.1007764-3-nathanl@linux.ibm.com
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b664db8e |
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18-May-2020 |
Leonardo Bras <leobras.c@gmail.com> |
powerpc/rtas: Implement reentrant rtas call Implement rtas_call_reentrant() for reentrant rtas-calls: "ibm,int-on", "ibm,int-off",ibm,get-xive" and "ibm,set-xive". On LoPAPR Version 1.1 (March 24, 2016), from 7.3.10.1 to 7.3.10.4, items 2 and 3 say: 2 - For the PowerPC External Interrupt option: The * call must be reentrant to the number of processors on the platform. 3 - For the PowerPC External Interrupt option: The * argument call buffer for each simultaneous call must be physically unique. So, these rtas-calls can be called in a lockless way, if using a different buffer for each cpu doing such rtas call. For this, it was suggested to add the buffer (struct rtas_args) in the PACA struct, so each cpu can have it's own buffer. The PACA struct received a pointer to rtas buffer, which is allocated in the memory range available to rtas 32-bit. Reentrant rtas calls are useful to avoid deadlocks in crashing, where rtas-calls are needed, but some other thread crashed holding the rtas.lock. This is a backtrace of a deadlock from a kdump testing environment: #0 arch_spin_lock #1 lock_rtas () #2 rtas_call (token=8204, nargs=1, nret=1, outputs=0x0) #3 ics_rtas_mask_real_irq (hw_irq=4100) #4 machine_kexec_mask_interrupts #5 default_machine_crash_shutdown #6 machine_crash_shutdown #7 __crash_kexec #8 crash_kexec #9 oops_end Signed-off-by: Leonardo Bras <leobras.c@gmail.com> [mpe: Move under #ifdef PSERIES to avoid build breakage] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200518234245.200672-3-leobras.c@gmail.com
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783a015b |
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18-May-2020 |
Leonardo Bras <leobras.c@gmail.com> |
powerpc/rtas: Move type/struct definitions from rtas.h into rtas-types.h In order to get any rtas* struct into other headers, including rtas.h may cause a lot of errors, regarding include dependency needed for inline functions. Create rtas-types.h and move there all type/struct definitions from rtas.h, then include rtas-types.h into rtas.h. Also, as suggested by checkpath.pl, replace uint8_t for u8. Signed-off-by: Leonardo Bras <leobras.c@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200518234245.200672-2-leobras.c@gmail.com
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#
8ba21426 |
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25-May-2020 |
Kajol Jain <kjain@linux.ibm.com> |
powerpc/hv-24x7: Add rtas call in hv-24x7 driver to get processor details For hv_24x7 socket/chip level events, specific chip-id to which the data requested should be added as part of pmu events. But number of chips/socket in the system details are not exposed. Patch implements read_24x7_sys_info() to get system parameter values like number of sockets, cores per chip and chips per socket. Rtas_call with token "PROCESSOR_MODULE_INFO" is used to get these values. Subsequent patch exports these values via sysfs. Patch also make these parameters default to 1. Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200525104308.9814-3-kjain@linux.ibm.com
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2874c5fd |
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27-May-2019 |
Thomas Gleixner <tglx@linutronix.de> |
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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8dce6b22 |
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22-Oct-2018 |
Tyrel Datwyler <tyreld@linux.vnet.ibm.com> |
powerpc/pseries: add missing cpumask.h include file Build error is encountered when inlcuding <asm/rtas.h> if no explicit or implicit include of cpumask.h exists in the including file. In file included from arch/powerpc/platforms/pseries/hotplug-pci.c:3:0: ./arch/powerpc/include/asm/rtas.h:360:34: error: unknown type name 'cpumask_var_t' extern int rtas_online_cpus_mask(cpumask_var_t cpus); ^ ./arch/powerpc/include/asm/rtas.h:361:35: error: unknown type name 'cpumask_var_t' extern int rtas_offline_cpus_mask(cpumask_var_t cpus); Fixes: 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation") Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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#
4c5d87db |
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14-Oct-2018 |
Oliver O'Halloran <oohall@gmail.com> |
powerpc/pseries: PAPR persistent memory support This patch implements support for discovering storage class memory devices at boot and for handling hotplug of new regions via RTAS hotplug events. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> [mpe: Fix CONFIG_MEMORY_HOTPLUG=n build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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#
8f0b8056 |
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11-Sep-2018 |
Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> |
powerpc/pseries: Display machine check error details. Extract the MCE error details from RTAS extended log and display it to console. With this patch you should now see mce logs like below: [ 142.371818] Severe Machine check interrupt [Recovered] [ 142.371822] NIP [d00000000ca301b8]: init_module+0x1b8/0x338 [bork_kernel] [ 142.371822] Initiator: CPU [ 142.371823] Error type: SLB [Multihit] [ 142.371824] Effective address: d00000000ca70000 Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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#
04fce21c |
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11-Sep-2018 |
Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> |
powerpc/pseries: Define MCE error event section. On pseries, the machine check error details are part of RTAS extended event log passed under Machine check exception section. This patch adds the definition of rtas MCE event section and related helper functions. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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#
5bfd6435 |
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23-Apr-2018 |
Arnd Bergmann <arnd@arndb.de> |
powerpc: use time64_t in read_persistent_clock 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>
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333f7b76 |
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15-Feb-2017 |
Sahil Mehta <sahilmehta17@gmail.com> |
powerpc/pseries: Implement indexed-count hotplug memory add Indexed-count add for memory hotplug guarantees that a contiguous block of <count> lmbs beginning at a specified <drc index> will be assigned, any LMBs in this range that are not already assigned will be DLPAR added. Because of Qemu's per-DIMM memory management, the addition of a contiguous block of memory currently requires a series of individual calls to add each LMB in the block. Indexed-count add reduces this series of calls to a single call for the entire block. Signed-off-by: Sahil Mehta <sahilmehta17@gmail.com> Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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#
e70d5970 |
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06-Jan-2017 |
John Allen <jallen@linux.vnet.ibm.com> |
powerpc/pseries: Introduce memory hotplug READD operation Currently, memory must be hot removed and subsequently re-added in order to dynamically update the affinity of LMBs specified by a PRRN event. Earlier implementations of the PRRN event handler ran into issues in which the hot remove would occur successfully, but a hotplug event would be initiated from another source and grab the hotplug lock preventing the hot add from occurring. To prevent this situation, this patch introduces the notion of a hot "readd" action for memory which atomizes a hot remove and a hot add into a single, serialized operation on the hotplug queue. Signed-off-by: John Allen <jallen@linux.vnet.ibm.com> Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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#
b1923caa |
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04-Jul-2016 |
Benjamin Herrenschmidt <benh@kernel.crashing.org> |
powerpc: Merge 32-bit and 64-bit setup_arch() There is little enough differences now. mpe: Add a/p/k/setup.h to contain the prototypes and empty versions of functions we need, rather than using weak functions. Add a few other empty versions to avoid as many #ifdefs as possible in the code. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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95ec77c0 |
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11-Jul-2016 |
Daniel Axtens <dja@axtens.net> |
powerpc: Make ppc_md.{halt, restart} __noreturn powernv marks it's halt and restart calls as __noreturn. However, ppc_md does not have this annotation. Add the annotation to ppc_md, and then to every halt/restart function that is missing it. Additionally, I have verified that all of these functions do not return. Occasionally I have added a spin loop to be sure. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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cd5cdeb6 |
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24-Nov-2015 |
Michael Ellerman <mpe@ellerman.id.au> |
powerpc/rtas: Make enter_rtas() private There are no longer any users of enter_rtas() outside of rtas.c, so make it "private", by moving the declaration inside rtas.c. Hopefully this will encourage people to use one of the wrappers which takes the sharp edges off the RTAS calling sequence. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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209eb4e5 |
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16-Dec-2015 |
Michael Ellerman <mpe@ellerman.id.au> |
powerpc/rtas: Add rtas_call_unlocked() Most users of RTAS (Run-Time Abstraction Services) use rtas_call(), which deals with locking as well as endian handling. However we have two users outside of rtas.c that can't use rtas_call() because they have different locking requirements. The hotplug CPU code can't take the RTAS lock because the CPU would go offline with the lock held and no other CPUs would be able to call RTAS until the CPU came back online. The xmon code doesn't want to take the lock because it would risk dead locking when we are trying to recover from a crash. Both sites required multiple patches when we added little endian support, proving that programmers can't do endian right. Although that ship has sailed, we can still clean the code up by providing an unlocked version of rtas_call() which avoids the need to open code the logic elsewhere. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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1c2cb594 |
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16-Jul-2015 |
Thomas Huth <thuth@redhat.com> |
powerpc/rtas: Introduce rtas_get_sensor_fast() for IRQ handlers The EPOW interrupt handler uses rtas_get_sensor(), which in turn uses rtas_busy_delay() to wait for RTAS becoming ready in case it is necessary. But rtas_busy_delay() is annotated with might_sleep() and thus may not be used by interrupts handlers like the EPOW handler! This leads to the following BUG when CONFIG_DEBUG_ATOMIC_SLEEP is enabled: BUG: sleeping function called from invalid context at arch/powerpc/kernel/rtas.c:496 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.2.0-rc2-thuth #6 Call Trace: [c00000007ffe7b90] [c000000000807670] dump_stack+0xa0/0xdc (unreliable) [c00000007ffe7bc0] [c0000000000e1f14] ___might_sleep+0x134/0x180 [c00000007ffe7c20] [c00000000002aec0] rtas_busy_delay+0x30/0xd0 [c00000007ffe7c50] [c00000000002bde4] rtas_get_sensor+0x74/0xe0 [c00000007ffe7ce0] [c000000000083264] ras_epow_interrupt+0x44/0x450 [c00000007ffe7d90] [c000000000120260] handle_irq_event_percpu+0xa0/0x300 [c00000007ffe7e70] [c000000000120524] handle_irq_event+0x64/0xc0 [c00000007ffe7eb0] [c000000000124dbc] handle_fasteoi_irq+0xec/0x260 [c00000007ffe7ef0] [c00000000011f4f0] generic_handle_irq+0x50/0x80 [c00000007ffe7f20] [c000000000010f3c] __do_irq+0x8c/0x200 [c00000007ffe7f90] [c0000000000236cc] call_do_irq+0x14/0x24 [c00000007e6f39e0] [c000000000011144] do_IRQ+0x94/0x110 [c00000007e6f3a30] [c000000000002594] hardware_interrupt_common+0x114/0x180 Fix this issue by introducing a new rtas_get_sensor_fast() function that does not use rtas_busy_delay() - and thus can only be used for sensors that do not cause a BUSY condition - known as "fast" sensors. The EPOW sensor is defined to be "fast" in sPAPR - mpe. Fixes: 587f83e8dd50 ("powerpc/pseries: Use rtas_get_sensor in RAS code") Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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c03e7374 |
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27-Mar-2015 |
Tyrel Datwyler <tyreld@linux.vnet.ibm.com> |
powerpc/pseries: Simplify check for suspendability during suspend/migration During suspend/migration operation we must wait for the VASI state reported by the hypervisor to become Suspending prior to making the ibm,suspend-me RTAS call. Calling routines to rtas_ibm_supend_me() pass a vasi_state variable that exposes the VASI state to the caller. This is unnecessary as the caller only really cares about the following three conditions; if there is an error we should bailout, success indicating we have suspended and woken back up so proceed to device tree update, or we are not suspendable yet so try calling rtas_ibm_suspend_me again shortly. This patch removes the extraneous vasi_state variable and simply uses the return code to communicate how to proceed. We either succeed, fail, or get -EAGAIN in which case we sleep for a second before trying to call rtas_ibm_suspend_me again. The behaviour of ppc_rtas() remains the same, but migrate_store() now returns the propogated error code on failure. Previously -1 was returned from migrate_store() in the failure case which equates to -EPERM and was clearly wrong. Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Cc: Nathan Fontenont <nfont@linux.vnet.ibm.com> Cc: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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e4a9616c |
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05-Feb-2015 |
Hari Bathini <hbathini@linux.vnet.ibm.com> |
powerpc/rtas: Make timestamp related code y2038-safe While we are here, let us make timestamp related code y2038-safe. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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78989f0a |
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05-Feb-2015 |
Hari Bathini <hbathini@linux.vnet.ibm.com> |
powerpc/nvram: Move generic code for nvram and pstore With minor checks, we can move most of the code for nvram under pseries to a common place to be re-used by other powerpc platforms like powernv. This patch moves such common code to arch/powerpc/kernel/nvram_64.c file. Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com> [mpe: Move select of ZLIB_DEFLATE to PPC64 to fix the build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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366d395c |
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10-Feb-2015 |
Nathan Fontenot <nfont@linux.vnet.ibm.com> |
powerpc/pseries: Define rtas hotplug event sections In order to handle device hotplug in the kernel on pseries the hotplug request will be communicated in the kernel in the form of a rtas hotplug event. This patch adds the definition of rtas hotplug event sections. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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3df76a9d |
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20-Jan-2015 |
Cyril Bur <cyrilbur@gmail.com> |
powerpc/pseries: Fix endian problems with LE migration RTAS events require arguments be passed in big endian while hypercalls have their arguments passed in registers and the values should therefore be in CPU endian. The "ibm,suspend_me" 'RTAS' call makes a sequence of hypercalls to setup one true RTAS call. This means that "ibm,suspend_me" is handled specially in the ppc_rtas() syscall. The ppc_rtas() syscall has its arguments in big endian and can therefore pass these arguments directly to the RTAS call. "ibm,suspend_me" is handled specially from within ppc_rtas() (by calling rtas_ibm_suspend_me()) which has left an endian bug on little endian systems due to the requirement of hypercalls. The return value from rtas_ibm_suspend_me() gets returned in cpu endian, and is left unconverted, also a bug on little endian systems. rtas_ibm_suspend_me() does not actually make use of the rtas_args that it is passed. This patch removes the convoluted use of the rtas_args struct to pass params to rtas_ibm_suspend_me() in favour of passing what it needs as actual arguments. This patch also ensures the two callers of rtas_ibm_suspend_me() pass function parameters in cpu endian and in the case of ppc_rtas(), converts the return value. migrate_store() (the other caller of rtas_ibm_suspend_me()) is from a sysfs file which deals with everything in cpu endian so this function only underwent cleanup. This patch has been tested with KVM both LE and BE and on PowerVM both LE and BE. Under QEMU/KVM the migration happens without touching these code pathes. For PowerVM there is no obvious regression on BE and the LE code path now provides the correct parameters to the hypervisor. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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a08a53ea |
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04-Apr-2014 |
Greg Kurz <groug@kaod.org> |
powerpc/le: Enable RTAS events support The current kernel code assumes big endian and parses RTAS events all wrong. The most visible effect is that we cannot honor EPOW events, meaning, for example, we cannot shut down a guest properly from the hypervisor. This new patch is largely inspired by Nathan's work: we get rid of all the bit fields in the RTAS event structures (even the unused ones, for consistency). We also introduce endian safe accessors for the fields used by the kernel (trivial rtas_error_type() accessor added for consistency). Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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6b36ba84 |
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25-Feb-2014 |
Haren Myneni <hbabu@us.ibm.com> |
powerpc/pseries: Update dynamic cache nodes for suspend/resume operation pHyp can change cache nodes for suspend/resume operation. Currently the device tree is updated by drmgr in userspace after all non boot CPUs are enabled. Hence, we do not modify the cache list based on the latest cache nodes. Also we do not remove cache entries for the primary CPU. This patch removes the cache list for the boot CPU, updates the device tree before enabling nonboot CPUs and adds cache list for the boot cpu. This patch also has the side effect that older versions of drmgr will perform a second device tree update from userspace. While this is a redundant waste of a couple cycles it is harmless since firmware returns the same data for the subsequent update-nodes/properties rtas calls. Signed-off-by: Haren Myneni <hbabu@us.ibm.com> Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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27128264 |
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06-Aug-2013 |
Anton Blanchard <anton@samba.org> |
powerpc: Make RTAS calls endian safe RTAS expects arguments in the call buffer to be big endian so we need to byteswap on little endian builds Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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061d19f2 |
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24-Jun-2013 |
Paul Gortmaker <paul.gortmaker@windriver.com> |
powerpc: Delete __cpuinit usage from all users The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the powerpc uses of the __cpuinit macros. There are no __CPUINIT users in assembly files in powerpc. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Josh Boyer <jwboyer@gmail.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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120496ac |
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06-May-2013 |
Robert Jennings <rcj@linux.vnet.ibm.com> |
powerpc: Bring all threads online prior to migration/hibernation This patch brings online all threads which are present but not online prior to migration/hibernation. After migration/hibernation those threads are taken back offline. During migration/hibernation all online CPUs must call H_JOIN, this is required by the hypervisor. Without this patch, threads that are offline (H_CEDE'd) will not be woken to make the H_JOIN call and the OS will be deadlocked (all threads either JOIN'd or CEDE'd). Cc: <stable@kernel.org> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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49c68a85 |
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23-Apr-2013 |
Jesse Larrew <jlarrew@linux.vnet.ibm.com> |
powerpc/pseries: Add PRRN RTAS event handler A PRRN event is signaled via the RTAS event-scan mechanism, which returns a Hot Plug Event message "fixed part" indicating "Platform Resource Reassignment". In response to the Hot Plug Event message, we must call ibm,update-nodes to determine which resources were reassigned and then ibm,update-properties to obtain the new affinity information about those resources. The PRRN event-scan RTAS message contains only the "fixed part" with the "Type" field set to the value 160 and no Extended Event Log. The four-byte Extended Event Log Length field is re-purposed (since no Extended Event Log message is included) to pass the "scope" parameter that causes the ibm,update-nodes to return the nodes affected by the specific resource reassignment. This patch adds a handler for RTAS events. The function pseries_devicetree_update() (from mobility.c) is used to make the ibm,update-nodes/ibm,update-properties RTAS calls. Updating the NUMA maps (handled by a subsequent patch) will require significant processing, so pseries_devicetree_update() is called from an asynchronous workqueue to allow event processing to continue. PRRN RTAS events on pseries systems are rare events that have to be initiated from the HMC console for the system by an IBM tech. This allows us to assume that these events are widely spaced. Additionally, all work on the queue is flushed before handling any new work to ensure we only have one event in flight being handled at a time. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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762ec157 |
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23-Apr-2013 |
Nathan Fontenot <nfont@linux.vnet.ibm.com> |
powerpc/pseries: Expose pseries devicetree_update() Newer firmware on Power systems can transparently reassign platform resources (CPU and Memory) in use. For instance, if a processor or memory unit is predicted to fail, the platform may transparently move the processing to an equivalent unused processor or the memory state to an equivalent unused memory unit. However, reassigning resources across NUMA boundaries may alter the performance of the partition. When such reassignment is necessary, the Platform Resource Reassignment Notification (PRRN) option provides a mechanism to inform the Linux kernel of changes to the NUMA affinity of its platform resources. When rtasd receives a PRRN event, it needs to make a series of RTAS calls (ibm,update-nodes and ibm,update-properties) to retrieve the updated device tree information. These calls are already handled in the pseries_devicetree_update() routine used in partition migration. This patch exposes pseries_devicetree_update() to make it accessible to other pseries routines, this patch also updates pseries_devicetree_update() to take a 32-bit scope parameter. The scope value, which was previously hard coded to 1 for partition migration, is used for the RTAS calls ibm,update-nodes/properties to update the device tree. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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f459d63e |
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02-Oct-2012 |
Nathan Fontenot <nfont@linux.vnet.ibm.com> |
powerpc+of: Remove the pSeries_reconfig.h file Remove the pSeries_reconfig.h header file. At this point there is only one definition in the file, pSeries_coalesce_init(), which can be moved to rtas.h. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Acked-by: Rob Herring <rob.herring@calxeda.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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ae3a197e |
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28-Mar-2012 |
David Howells <dhowells@redhat.com> |
Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PowerPC. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> cc: linuxppc-dev@lists.ozlabs.org
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6f43747f |
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21-Mar-2012 |
Anton Blanchard <anton@samba.org> |
powerpc/pseries: Remove RTAS_POWERMGM_EVENTS IBM bit 2 in the rtas event-scan and check-exception calls is marked reserved in the PAPR, so remove it from our RAS code. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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6431f208 |
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21-Mar-2012 |
Anton Blanchard <anton@samba.org> |
powerpc: Make function that parses RTAS error logs global The IO event interrupt code has a function that finds specific sections in an RTAS error log. We want to use it in the EPOW code so make it global. Rename things to make it less cryptic: find_xelog_section() -> get_pseries_errorlog() struct pseries_elog_section -> struct pseries_errorlog Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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8a3e3d31 |
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01-Dec-2011 |
sukadev@linux.vnet.ibm.com <sukadev@linux.vnet.ibm.com> |
powerpc: Punch a hole in /dev/mem for librtas With CONFIG_STRICT_DEVMEM=y, user space cannot read any part of /dev/mem. Since this breaks librtas, punch a hole in /dev/mem to allow access to the rmo_buffer that librtas needs. Anton Blanchard reported the problem and helped with the fix. A quick test for this patch: # cat /proc/rtas/rmo_buffer 000000000f190000 10000 # python -c "print 0x000000000f190000 / 0x10000" 3865 # dd if=/dev/mem of=/tmp/foo count=1 bs=64k skip=3865 1+0 records in 1+0 records out 65536 bytes (66 kB) copied, 0.000205235 s, 319 MB/s # dd if=/dev/mem of=/tmp/foo dd: reading `/dev/mem': Operation not permitted 0+0 records in 0+0 records out 0 bytes (0 B) copied, 0.00022519 s, 0.0 kB/s Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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df17f56d |
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03-Oct-2011 |
Ravi K. Nittala <ravi.nittala@in.ibm.com> |
powerpc/pseries: Cancel RTAS event scan before firmware flash The RTAS firmware flash update is conducted using an RTAS call that is serialized by lock_rtas() which uses spin_lock. While the flash is in progress, rtasd performs scan for any RTAS events that are generated by the system. rtasd keeps scanning for the RTAS events generated on the machine. This is performed via workqueue mechanism. The rtas_event_scan() also uses an RTAS call to scan the events, eventually trying to acquire the spin_lock before issuing the request. The flash update takes a while to complete and during this time, any other RTAS call has to wait. In this case, rtas_event_scan() waits for a long time on the spin_lock resulting in a soft lockup. Fix: Just before the flash update is performed, the queued rtas_event_scan() work item is cancelled from the work queue so that there is no other RTAS call issued while the flash is in progress. After the flash completes, the system reboots and the rtas_event_scan() is rescheduled. Signed-off-by: Suzuki Poulose <suzuki@in.ibm.com> Signed-off-by: Ravi Nittala <ravi.nittala@in.ibm.com> Reported-by: Divya Vikas <divya.vikas@in.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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6c493685 |
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25-Jul-2011 |
Jim Keniston <jkenisto@us.ibm.com> |
powerpc/nvram: Add compression to fit more oops output into NVRAM Capture more than twice as much text from the printk buffer, and compress it to fit it in the lnx,oops-log NVRAM partition. You can view the compressed text using the new (as of July 20) --unzip option of the nvram command in the powerpc-utils package. [BenH: Added select of ZLIB_DEFLATE] Signed-off-by: Jim Keniston <jkenisto@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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4cb46380 |
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03-May-2011 |
Tseng-Hui (Frank) Lin <thlin@linux.vnet.ibm.com> |
powerpc/pseries: Add RTAS event log v6 definition This patch adds definitions of non-IBM specific v6 extended log definitions to rtas.h. Signed-off-by: Tseng-Hui (Frank) Lin <tsenglin@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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d8862be1 |
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10-Sep-2010 |
Nathan Fontenot <nfont@austin.ibm.com> |
powerpc/pseries: Export rtas_ibm_suspend_me() Export the rtas_ibm_suspend_me() routine. This is needed to perform partition migration in the kernel. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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b08e281b |
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26-May-2010 |
Mark Nelson <markn@au1.ibm.com> |
powerpc/pseries: Rename RAS_VECTOR_OFFSET to RTAS_VECTOR_EXTERNAL_INTERRUPT and move to rtas.h The RAS code has a #define, RAS_VECTOR_OFFSET, that's used in the check-exception RTAS call for the vector offset of the exception. We'll be using this same vector offset for the upcoming IO Event interrupts code (0x500) so let's move it to include/asm/rtas.h and call it RTAS_VECTOR_EXTERNAL_INTERRUPT. Signed-off-by: Mark Nelson <markn@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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8fe93f8d |
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06-Jul-2010 |
Brian King <brking@linux.vnet.ibm.com> |
powerpc/pseries: Migration code reorganization / hibernation prep Partition hibernation will use some of the same code as is currently used for Live Partition Migration. This function further abstracts this code such that code outside of rtas.c can utilize it. It also changes the error field in the suspend me data structure to be an atomic type, since it is set and checked on different cpus without any barriers or locking. Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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445c8951 |
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02-Dec-2009 |
Thomas Gleixner <tglx@linutronix.de> |
locking: Convert raw_spinlock to arch_spinlock The raw_spin* namespace was taken by lockdep for the architecture specific implementations. raw_spin_* would be the ideal name space for the spinlocks which are not converted to sleeping locks in preempt-rt. Linus suggested to convert the raw_ to arch_ locks and cleanup the name space instead of using an artifical name like core_spin, atomic_spin or whatever No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
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c4007a2f |
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16-Jun-2009 |
Benjamin Herrenschmidt <benh@kernel.crashing.org> |
powerpc: Use one common impl. of RTAS timebase sync and use raw spinlock Several platforms use their own copy of what is essentially the same code, using RTAS to synchronize the timebases when bringing up new CPUs. This moves it all into a single common implementation and additionally turns the spinlock into a raw spinlock since the former can rely on the timebase not being frozen when spinlock debugging is enabled, and finally masks interrupts while the timebase is disabled. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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f97bb36f |
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16-Jun-2009 |
Benjamin Herrenschmidt <benh@kernel.crashing.org> |
powerpc/rtas: Turn rtas lock into a raw spinlock RTAS currently uses a normal spinlock. However it can be called from contexts where this is not necessarily a good idea. For example, it can be called while syncing timebases, with the core timebase being frozen. Unfortunately, that will deadlock in case of lock contention when spinlock debugging is enabled as the spin lock debugging code will try to use __delay() which ... relies on the timebase being enabled. Also RTAS can be used in some low level IRQ handling code path so it may as well be a raw spinlock for -rt sake. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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4a9f9506 |
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31-Mar-2009 |
Anton Blanchard <anton@samba.org> |
powerpc/pseries: Scan for all events in rtasd Instead of checking for known events, pass in all 1s so we handle future event types. We were currently missing the IO event type. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
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fe333321 |
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06-Jan-2009 |
Ingo Molnar <mingo@elte.hu> |
powerpc: Change u64/s64 to a long long integer type Convert arch/powerpc/ over to long long based u64: -#ifdef __powerpc64__ -# include <asm-generic/int-l64.h> -#else -# include <asm-generic/int-ll64.h> -#endif +#include <asm-generic/int-ll64.h> This will avoid reoccuring spurious warnings in core kernel code that comes when people test on their own hardware. (i.e. x86 in ~98% of the cases) This is what x86 uses and it generally helps keep 64-bit code 32-bit clean too. [Adjusted to not impact user mode (from paulus) - sfr] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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edc72ac4 |
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11-Dec-2008 |
Nathan Lynch <ntl@pobox.com> |
powerpc/pseries: Check for GIQ indicator before calling set-indicator Since "Factor out cpu joining/unjoining the GIQ" (b4963255ad5a426f04a0bb15c4315fa4bb40cde9) the WARN_ON in xics_set_cpu_giq() is being triggered during boot on JS20 because the GIQ indicator is not available on that platform. While the warning is harmless and the system runs normally, it's nicer to check for the existence of the indicator before trying to manipulate it. Implement rtas_indicator_present(), which searches the /rtas/rtas-indicators property for the given indicator token, and use this function in xics_set_cpu_giq(). Also use a WARN statement in xics_set_cpu_giq to get better information on failure. Signed-off-by: Nathan Lynch <ntl@pobox.com> Acked-by: Milton Miller <miltonm@bga.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
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b8b572e1 |
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31-Jul-2008 |
Stephen Rothwell <sfr@canb.auug.org.au> |
powerpc: Move include files to arch/powerpc/include/asm from include/asm-powerpc. This is the result of a mkdir arch/powerpc/include/asm git mv include/asm-powerpc/* arch/powerpc/include/asm Followed by a few documentation/comment fixups and a couple of places where <asm-powepc/...> was being used explicitly. Of the latter only one was outside the arch code and it is a driver only built for powerpc. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
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