- 09 Dec, 2020 7 commits
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Christophe Leroy authored
Hash related vars are used at init only. Declare them in __initdata. Signed-off-by:
Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3878ea30706839fcff9196790ff3f99c128c3f6a.1603348103.git.christophe.leroy@csgroup.eu
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Christophe Leroy authored
Hash var is used only locally in mmu.c now. No need to set it in head_32.S anymore. Make it static and initialises it to the early hash table. Signed-off-by:
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Christophe Leroy authored
We now have an early hash table on hash MMU, so no need to check Hash var to know if the Hash table is set of not. Use mmu_has_feature(MMU_FTR_HPTE_TABLE) instead. This will allow optimisation via jump_label. Signed-off-by:
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Christophe Leroy authored
This table is used only locally. Declare it static. Signed-off-by:
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Christophe Leroy authored
flush_tlb_page_nohash() was removed by commit 703b41ad ("powerpc/mm: remove flush_tlb_page_nohash") Remove stale prototype and comment. Signed-off-by:
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Christophe Leroy authored
On the same principle as commit 773edead ("powerpc/mm: Add mask of possible MMU features"), add mask for MMU features that are always there in order to optimise out dead branches. Signed-off-by:
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Tyrel Datwyler authored
Commit bd59380c ("powerpc/rtas: Restrict RTAS requests from userspace") introduced the following error when invoking the errinjct userspace tool: [root@ltcalpine2-lp5 librtas]# errinjct open [327884.071171] sys_rtas: RTAS call blocked - exploit attempt? [327884.071186] sys_rtas: token=0x26, nargs=0 (called by errinjct) errinjct: Could not open RTAS error injection facility errinjct: librtas: open: Unexpected I/O error The entry for ibm,open-errinjct in rtas_filter array has a typo where the "j" is omitted in the rtas call name. After fixing this typo the errinjct tool functions again as expected. [root@ltcalpine2-lp5 linux]# errinjct open RTAS error injection facility open, token = 1 Fixes: bd59380c ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Signed-off-by:
Tyrel Datwyler <tyreld@linux.ibm.com> Signed-off-by:
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- 08 Dec, 2020 31 commits
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Christophe Leroy authored
low_sleep_handler() can't restore the context from standard stack because the stack can hardly be accessed with MMU OFF. Store everything in a global storage area instead of storing a pointer to the stack in that global storage area. To avoid a complete churn of the function, still use r1 as the pointer to the storage area during restore. Fixes: cd08f109 ("powerpc/32s: Enable CONFIG_VMAP_STACK") Reported-by:
Giuseppe Sacco <giuseppe@sguazz.it> Signed-off-by:
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Colin Ian King authored
There is a spelling mistake in the help text of the Kconfig. Fix it. Signed-off-by:
Colin Ian King <colin.king@canonical.com> Signed-off-by:
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Nathan Lynch authored
In pseries_devicetree_update(), with each call to ibm,update-nodes the partition firmware communicates the node to be deleted or updated by placing its phandle in the work buffer. Each of delete_dt_node(), update_dt_node(), and add_dt_node() have duplicate lookups using the phandle value and corresponding refcount management. Move the lookup and of_node_put() into pseries_devicetree_update(), and emit a warning on any failed lookups. Signed-off-by:
Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by:
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Nathan Lynch authored
All code which used this type has been removed. Signed-off-by:
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Nathan Lynch authored
The pseries hibernate code no longer calls into the original join/suspend code in kernel/rtas.c, so pseries_prepare_late() and related code don't accomplish anything now. Signed-off-by:
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Nathan Lynch authored
The pseries hibernate code calls post_mobility_fixup() which is sort of a dumping ground of fixups that need to run after resuming from suspend regardless of whether suspend was a hibernation or a migration. Calling post_mobility_fixup() from pseries_suspend_enable_irqs() runs this code early in resume with devices suspended and only one CPU up, while the much more commonly used migration case runs these fixups in a more typical process context. Call post_mobility_fixup() after the suspend core returns a success status to the hibernate sysfs store method and remove pseries_suspend_enable_irqs(). Signed-off-by:
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Nathan Lynch authored
Partitions with cache nodes in the device tree can encounter the following warning on resume: CPU 0 already accounted in PowerPC,POWER9@0(Data) WARNING: CPU: 0 PID: 3177 at arch/powerpc/kernel/cacheinfo.c:197 cacheinfo_cpu_online+0x640/0x820 These calls to cacheinfo_cpu_offline/online have been redundant since commit e610a466 ("powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration"). Fixes: e610a466 ("powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration") Signed-off-by:
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Nathan Lynch authored
rtas_suspend_last_cpu() is now unused, remove it and __rtas_suspend_last_cpu() which also becomes unused. Signed-off-by:
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Nathan Lynch authored
rtas_suspend_last_cpu() and related code perform a lot of work that isn't relevant to the hibernation workflow. All other CPUs are offline when called so there is no need to place them in H_JOIN or prod them on resume, nor is there need for retries or operations on shared state. Call the rtas_ibm_suspend_me() wrapper function directly from pseries_suspend_enter() instead of using rtas_suspend_last_cpu(). Signed-off-by:
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Nathan Lynch authored
rtas_suspend_cpu() no longer has users; remove it and __rtas_suspend_cpu() which now becomes unused as well. Signed-off-by:
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Nathan Lynch authored
There are no users left of the suspend_disable_cpu() callback, remove it. Signed-off-by:
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Nathan Lynch authored
Since commit 48f6e7f6 ("powerpc/pseries: remove cede offline state for CPUs"), ppc_md.suspend_disable_cpu() is no longer used and all CPUs (save one) are placed into true offline state as opposed to H_JOIN. So pseries_suspend_cpu() is effectively unused; remove it. Signed-off-by:
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Nathan Lynch authored
There is no need for the stream id to be a file-global variable; pass it from hibernate_store() to pseries_suspend_begin() for the H_VASI_STATE call. Signed-off-by:
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Nathan Lynch authored
There are three ways pseries_suspend_begin() can be reached: 1. When "mem" is written to /sys/power/state: kobj_attr_store() -> state_store() -> pm_suspend() -> suspend_devices_and_enter() -> pseries_suspend_begin() This never works because there is no way to supply a valid stream id using this interface, and H_VASI_STATE is called with a stream id of zero. So this call path is useless at best. 2. When a stream id is written to /sys/devices/system/power/hibernate. pseries_suspend_begin() is polled directly from store_hibernate() until the stream is in the "Suspending" state (i.e. the platform is ready for the OS to suspend execution): dev_attr_store() -> store_hibernate() -> pseries_suspend_begin() 3. When a stream id is written to /sys/devices/system/power/hibernate (continued). After #2, pseries_suspend_begin() is called once again from the pm core: dev_attr_store() -> store_hibernate() -> pm_suspend() -> suspend_devices_and_enter() -> pseries_suspend_begin() This is redundant because the VASI suspend state is already known to be Suspending. The begin() callback of platform_suspend_ops is optional, so we can simply remove that assignment with no loss of function. Fixes: 32d8ad4e ("powerpc/pseries: Partition hibernation support") Signed-off-by: -
Nathan Lynch authored
rtas_ibm_suspend_me_unsafe() is now unused; remove it and rtas_percpu_suspend_me() which becomes unused as a result. Signed-off-by:
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Nathan Lynch authored
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:
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Nathan Lynch authored
This is a mitigation for the relatively rare occurrence where a virtual IOA can be in a transient state that prevents the suspend/migration from succeeding, resulting in an error from ibm,suspend-me. If the join/suspend sequence returns an error, it is acceptable to retry as long as the VASI suspend session state is still "Suspending" (i.e. the platform is still waiting for the OS to suspend). Retry a few times on suspend failure while this condition holds, progressively increasing the delay between attempts. We don't want to retry indefinitey because firmware emits an error log event on each unsuccessful attempt. Signed-off-by:
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Nathan Lynch authored
If we're returning an error to user space, use H_VASI_SIGNAL to send a cancellation request to the platform. This isn't strictly required but it communicates that Linux will not attempt to complete the suspend, which allows the various entities involved to promptly end the operation in progress. Signed-off-by:
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Nathan Lynch authored
The partition suspend sequence as specified in the platform architecture requires that all active processor threads call H_JOIN, which: - suspends the calling thread until it is the target of an H_PROD; or - immediately returns H_CONTINUE, if the calling thread is the last to call H_JOIN. This thread is expected to call ibm,suspend-me to completely suspend the partition. Upon returning from ibm,suspend-me the calling thread must wake all others using H_PROD. rtas_ibm_suspend_me_unsafe() uses on_each_cpu() to implement this protocol, but because of its synchronizing nature this is susceptible to deadlock versus users of stop_machine() or other callers of on_each_cpu(). Not only is stop_machine() intended for use cases like this, it handles error propagation and allows us to keep the data shared between CPUs minimal: a single atomic counter which ensures exactly one CPU will wake the others from their joined states. Switch the migration code to use stop_machine() and a less complex local implementation of the H_JOIN/ibm,suspend-me logic, which carries additional benefits: - more informative error reporting, appropriately ratelimited - resets the lockup detector / watchdog on resume to prevent lockup warnings when the OS has been suspended for a time exceeding the threshold. Fixes: 91dc182c ("[PATCH] powerpc: special-case ibm,suspend-me RTAS call") Signed-off-by:
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Nathan Lynch authored
The behavior of rtas_ibm_suspend_me_unsafe() is to return -EAGAIN to the caller until the specified VASI suspend session state makes the transition from H_VASI_ENABLED to H_VASI_SUSPENDING. In the interest of separating concerns to prepare for a new implementation of the join/suspend sequence, extract VASI session polling logic into a couple of local functions. Waiting for the session state to reach H_VASI_SUSPENDING before calling rtas_ibm_suspend_me_unsafe() ensures that we will never get an EAGAIN result necessitating a retry. No user-visible change in behavior is intended. Signed-off-by:
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Nathan Lynch authored
It's incorrect to abort post-suspend processing if ibm,activate-firmware isn't available. Use rtas_activate_firmware(), which logs this condition appropriately and allows us to proceed. Signed-off-by:
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Nathan Lynch authored
- Convert printk(KERN_ERR) to pr_err(). - Include errno in property update failure message. - Remove reference to "Post-mobility" from device tree update message: with pr_err() it will have a "mobility:" prefix. Signed-off-by:
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Nathan Lynch authored
update_dt_node() has a switch statement where the default case lacks a break statement. Signed-off-by:
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Nathan Lynch authored
Treat the absence of the ibm,update-nodes function as benign instead of reporting an error. If the platform does not provide that facility, it's not a problem for Linux. Signed-off-by:
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Nathan Lynch authored
H_VASI_SIGNAL can be used by a partition to request cancellation of its migration. To be used in future changes. Signed-off-by:
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Nathan Lynch authored
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:
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Nathan Lynch authored
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:
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Nathan Lynch authored
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:
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Nathan Lynch authored
We don't completely account for the possible return codes for ibm,suspend-me. Add definitions for these. Signed-off-by:
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Nathan Lynch authored
While drmgr has had work in some areas to make its RTAS syscall interactions endian-neutral, its code for performing partition migration via the syscall has never worked on LE. While it is able to complete ibm,suspend-me successfully, it crashes when attempting the subsequent ibm,update-nodes call. drmgr is the only known (or plausible) user of ibm,suspend-me, ibm,update-nodes, and ibm,update-properties, so allow them only in big-endian configurations. Signed-off-by:
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Aneesh Kumar K.V authored
This partially reverts commit eb232b16 ("powerpc/book3s64/kuap: Improve error reporting with KUAP") and update the fault handler to print [ 55.022514] Kernel attempted to access user page (7e6725b70000) - exploit attempt? (uid: 0) [ 55.022528] BUG: Unable to handle kernel data access on read at 0x7e6725b70000 [ 55.022533] Faulting instruction address: 0xc000000000e8b9bc [ 55.022540] Oops: Kernel access of bad area, sig: 11 [#1] .... when the kernel access userspace address without unlocking AMR. bad_kuap_fault() is added as part of commit 5e5be3ae ("powerpc/mm: Detect bad KUAP faults") to catch userspace access incorrectly blocked by AMR. Hence retain the full stack dump there even with hash translation. Also, add a comment explaining the difference between hash and radix. Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by:
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- 07 Dec, 2020 2 commits
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Jordan Niethe authored
On Power9, CIABR is lost after idle. This means that instruction breakpoints set by xmon which use CIABR do not work. Fix this by restoring CIABR after idle. Signed-off-by:
Jordan Niethe <jniethe5@gmail.com> Signed-off-by:
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Jordan Niethe authored
The value in CIABR persists across kexec which can lead to unintended results when the new kernel hits the old kernel's breakpoint. For example: 0:mon> bi $loadavg_proc_show 0:mon> b type address 1 inst c000000000519060 loadavg_proc_show+0x0/0x130 0:mon> x $ kexec -l /mnt/vmlinux --initrd=/mnt/rootfs.cpio.gz --append='xmon=off' $ kexec -e $ cat /proc/loadavg Trace/breakpoint trap Make sure CIABR is cleared so this does not happen. Signed-off-by:
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