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2020-12-09powerpc/32s: Move early_mmu_init() into mmu.cChristophe Leroy2-4/+4
early_mmu_init() is independent of MMU type and not directly linked to tlb handling. In a following patch, tlb.c will be restricted to HASH mmu. Move early_mmu_init() into mmu.c which is common. Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/e51b5e2fe6bca623b33116403043d3a1b5eaf826.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Inline flush_hash_entry()Christophe Leroy3-23/+11
flush_hash_entry() is a simple function calling flush_hash_pages() if it's a hash MMU or doing nothing otherwise. Inline it. And use it also in __ptep_test_and_clear_young(). Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/9af895be7d4b404d40e749a2659552fd138e62c4.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Inline tlb_flush()Christophe Leroy2-15/+11
On book3s/32, tlb_flush() does nothing when the CPU has a hash table, it calls _tlbia() otherwise. Inline it. Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/ebc933d1c530a19ef3cf7983f6ae94814f6e92ac.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Split and inline flush_range()Christophe Leroy2-11/+15
flush_range() handle both the MMU_FTR_HPTE_TABLE case and the other case. The non MMU_FTR_HPTE_TABLE case is trivial as it is only a call to _tlbie()/_tlbia() which is not worth a dedicated function. Make flush_range() a hash specific and call it from tlbflush.h based on mmu_has_feature(MMU_FTR_HPTE_TABLE). Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/132ab19aae52abc8e06ab524ec86d4229b5b9c3d.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Inline flush_tlb_range() and flush_tlb_kernel_range()Christophe Leroy2-26/+19
flush_tlb_range() and flush_tlb_kernel_range() are trivial calls to flush_range(). Make flush_range() global and inline flush_tlb_range() and flush_tlb_kernel_range(). Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/c7029a78e78709ad9272d7a44260e06b649169b2.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Split and inline flush_tlb_mm() and flush_tlb_page()Christophe Leroy2-15/+22
flush_tlb_mm() and flush_tlb_page() handle both the MMU_FTR_HPTE_TABLE case and the other case. The non MMU_FTR_HPTE_TABLE case is trivial as it is only a call to _tlbie()/_tlbia() which is not worth a dedicated function. Make flush_tlb_mm() and flush_tlb_page() hash specific and call them from tlbflush.h based on mmu_has_feature(MMU_FTR_HPTE_TABLE). Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/11e932ded41ba6d9b251d89b7afa33cc060d3aa4.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Move _tlbie() and _tlbia() in a new fileChristophe Leroy4-79/+85
_tlbie() and _tlbia() are used only on 603 cores while the other functions are used only on cores having a hash table. Move them into a new file named nohash_low.S Add mmu_hash_lock var is used by both, it needs to go in a common file. Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/9a265b1b17a64153463d361280cb4b43eb1266a4.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Inline _tlbie() on non SMPChristophe Leroy2-5/+9
On non SMP, _tlbie() is just a tlbie plus a sync instruction. Make it static inline. Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/475136425541db5c7c8a0395d19d400525b251bc.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Move _tlbie() and _tlbia() prototypes to tlbflush.hChristophe Leroy2-3/+4
In order to use _tlbie() and _tlbia() directly from asm/book3s/32/tlbflush.h, move their prototypes from mm/mm_decl.h to there. Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/867587af929973ad65f8ef6972f2474a80c1737a.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Declare Hash related vars as __initdataChristophe Leroy1-4/+4
Hash related vars are used at init only. Declare them in __initdata. Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/3878ea30706839fcff9196790ff3f99c128c3f6a.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Make Hash var staticChristophe Leroy3-7/+1
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: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/786c82a89cdfdaabb32b72a44f7c312fa81d192b.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Use mmu_has_feature(MMU_FTR_HPTE_TABLE) instead of checking ↵Christophe Leroy2-6/+6
Hash var 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: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/f1766631a9e014b6433f1a3c12c726ddfce34220.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Make bat_addrs[] staticChristophe Leroy1-1/+1
This table is used only locally. Declare it static. Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/054fec0c139fc4c0a306360b360784733c0a6e65.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/mm: Remove flush_tlb_page_nohash() prototype.Christophe Leroy2-2/+0
flush_tlb_page_nohash() was removed by commit 703b41ad1a87 ("powerpc/mm: remove flush_tlb_page_nohash") Remove stale prototype and comment. Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/4a58831da6d6ba4fe309b94aa1dd8f02982d46b2.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/mm: Add mask of always present MMU featuresChristophe Leroy1-0/+25
On the same principle as commit 773edeadf672 ("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: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/4943775fbe91885eb3e09133b093aaf62e55c715.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/rtas: Fix typo of ibm,open-errinjct in RTAS filterTyrel Datwyler1-1/+1
Commit bd59380c5ba4 ("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: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: [email protected] Signed-off-by: Tyrel Datwyler <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/configs: drop unused BACKLIGHT_GENERIC optionAndrey Zhizhikin1-1/+0
Commit 7ecdea4a0226 ("backlight: generic_bl: Remove this driver as it is unused") removed geenric_bl driver from the tree, together with corresponding config option. Remove BACKLIGHT_GENERIC config item from generic-64bit_defconfig. Fixes: 7ecdea4a0226 ("backlight: generic_bl: Remove this driver as it is unused") Signed-off-by: Andrey Zhizhikin <[email protected]> Reviewed-by: Krzysztof Kozlowski <[email protected]> Acked-by: Daniel Thompson <[email protected]> Acked-by: Sam Ravnborg <[email protected]> Acked-by: Michael Ellerman <[email protected]> Cc: Sam Ravnborg <[email protected]> Link: https://lore.kernel.org/r/[email protected]' Signed-off-by: Arnd Bergmann <[email protected]>
2020-12-08powerpc/powermac: Fix low_sleep_handler with CONFIG_VMAP_STACKChristophe Leroy2-74/+60
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: cd08f109e262 ("powerpc/32s: Enable CONFIG_VMAP_STACK") Reported-by: Giuseppe Sacco <[email protected]> Signed-off-by: Christophe Leroy <[email protected]> Tested-by: Giuseppe Sacco <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/e3e0d8042a3ba75cb4a9546c19c408b5b5b28994.1607404931.git.christophe.leroy@csgroup.eu
2020-12-08powerpc: fix spelling mistake in Kconfig "seleted" -> "selected"Colin Ian King1-1/+1
There is a spelling mistake in the help text of the Kconfig. Fix it. Signed-off-by: Colin Ian King <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/mobility: refactor node lookup during DT updateNathan Lynch1-32/+17
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 <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/rtas: remove unused rtas_suspend_me_dataNathan Lynch1-8/+0
All code which used this type has been removed. Signed-off-by: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/hibernation: remove prepare_late() callbackNathan Lynch1-25/+0
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: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/hibernation: perform post-suspend fixups laterNathan Lynch1-17/+4
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: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/hibernation: remove redundant cacheinfo updateNathan Lynch1-3/+0
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 e610a466d16a ("powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration"). Fixes: e610a466d16a ("powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration") Signed-off-by: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/rtas: remove unused rtas_suspend_last_cpu()Nathan Lynch2-44/+0
rtas_suspend_last_cpu() is now unused, remove it and __rtas_suspend_last_cpu() which also becomes unused. Signed-off-by: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/hibernation: switch to rtas_ibm_suspend_me()Nathan Lynch1-5/+1
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: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/rtas: remove rtas_suspend_cpu()Nathan Lynch2-53/+0
rtas_suspend_cpu() no longer has users; remove it and __rtas_suspend_cpu() which now becomes unused as well. Signed-off-by: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/machdep: remove suspend_disable_cpu()Nathan Lynch1-1/+0
There are no users left of the suspend_disable_cpu() callback, remove it. Signed-off-by: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/hibernation: remove pseries_suspend_cpu()Nathan Lynch1-15/+0
Since commit 48f6e7f6d948 ("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: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/hibernation: pass stream id via function argumentsNathan Lynch1-5/+3
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: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/hibernation: drop pseries_suspend_begin() from suspend opsNathan Lynch1-1/+0
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: 32d8ad4e621d ("powerpc/pseries: Partition hibernation support") Signed-off-by: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/rtas: remove rtas_ibm_suspend_me_unsafe()Nathan Lynch2-67/+1
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 <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/rtas: dispatch partition migration requests to pseriesNathan Lynch3-1/+11
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 <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/mobility: retry partition suspend after errorNathan Lynch1-2/+57
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: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/mobility: signal suspend cancellation to platformNathan Lynch1-0/+31
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: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/mobility: use stop_machine for join/suspendNathan Lynch1-7/+125
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: 91dc182ca6e2 ("[PATCH] powerpc: special-case ibm,suspend-me RTAS call") Signed-off-by: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/mobility: extract VASI session polling logicNathan Lynch1-5/+64
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: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/mobility: use rtas_activate_firmware() on resumeNathan Lynch1-14/+1
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: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/mobility: error message improvementsNathan Lynch1-4/+3
- 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: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/mobility: add missing break to default caseNathan Lynch1-0/+1
update_dt_node() has a switch statement where the default case lacks a break statement. Signed-off-by: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/pseries/mobility: don't error on absence of ibm, update-nodesNathan Lynch1-1/+1
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: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/hvcall: add token and codes for H_VASI_SIGNALNathan Lynch1-0/+9
H_VASI_SIGNAL can be used by a partition to request cancellation of its migration. To be used in future changes. Signed-off-by: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/rtas: add rtas_activate_firmware()Nathan Lynch2-0/+31
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 <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/rtas: add rtas_ibm_suspend_me()Nathan Lynch2-0/+58
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 <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/rtas: rtas_ibm_suspend_me -> rtas_ibm_suspend_me_unsafeNathan Lynch3-5/+5
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 <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/rtas: complete ibm,suspend-me status codesNathan Lynch1-1/+6
We don't completely account for the possible return codes for ibm,suspend-me. Add definitions for these. Signed-off-by: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/rtas: prevent suspend-related sys_rtas use on LENathan Lynch1-0/+2
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: Nathan Lynch <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/book3s64/kuap: Improve error reporting with KUAPAneesh Kumar K.V5-25/+25
This partially reverts commit eb232b162446 ("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 5e5be3aed230 ("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 <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-12-08powerpc/mm: Fix KUAP warning by providing copy_from_kernel_nofault_allowed()Christophe Leroy2-1/+10
Since commit c33165253492 ("powerpc: use non-set_fs based maccess routines"), userspace access is not granted anymore when using copy_from_kernel_nofault() However, kthread_probe_data() uses copy_from_kernel_nofault() to check validity of pointers. When the pointer is NULL, it points to userspace, leading to a KUAP fault and triggering the following big hammer warning many times when you request a sysrq "show task": [ 1117.202054] ------------[ cut here ]------------ [ 1117.202102] Bug: fault blocked by AP register ! [ 1117.202261] WARNING: CPU: 0 PID: 377 at arch/powerpc/include/asm/nohash/32/kup-8xx.h:66 do_page_fault+0x4a8/0x5ec [ 1117.202310] Modules linked in: [ 1117.202428] CPU: 0 PID: 377 Comm: sh Tainted: G W 5.10.0-rc5-01340-g83f53be2de31-dirty #4175 [ 1117.202499] NIP: c0012048 LR: c0012048 CTR: 00000000 [ 1117.202573] REGS: cacdbb88 TRAP: 0700 Tainted: G W (5.10.0-rc5-01340-g83f53be2de31-dirty) [ 1117.202625] MSR: 00021032 <ME,IR,DR,RI> CR: 24082222 XER: 20000000 [ 1117.202899] [ 1117.202899] GPR00: c0012048 cacdbc40 c2929290 00000023 c092e554 00000001 c09865e8 c092e640 [ 1117.202899] GPR08: 00001032 00000000 00000000 00014efc 28082224 100d166a 100a0920 00000000 [ 1117.202899] GPR16: 100cac0c 100b0000 1080c3fc 1080d685 100d0000 100d0000 00000000 100a0900 [ 1117.202899] GPR24: 100d0000 c07892ec 00000000 c0921510 c21f4440 0000005c c0000000 cacdbc80 [ 1117.204362] NIP [c0012048] do_page_fault+0x4a8/0x5ec [ 1117.204461] LR [c0012048] do_page_fault+0x4a8/0x5ec [ 1117.204509] Call Trace: [ 1117.204609] [cacdbc40] [c0012048] do_page_fault+0x4a8/0x5ec (unreliable) [ 1117.204771] [cacdbc70] [c00112f0] handle_page_fault+0x8/0x34 [ 1117.204911] --- interrupt: 301 at copy_from_kernel_nofault+0x70/0x1c0 [ 1117.204979] NIP: c010dbec LR: c010dbac CTR: 00000001 [ 1117.205053] REGS: cacdbc80 TRAP: 0301 Tainted: G W (5.10.0-rc5-01340-g83f53be2de31-dirty) [ 1117.205104] MSR: 00009032 <EE,ME,IR,DR,RI> CR: 28082224 XER: 00000000 [ 1117.205416] DAR: 0000005c DSISR: c0000000 [ 1117.205416] GPR00: c0045948 cacdbd38 c2929290 00000001 00000017 00000017 00000027 0000000f [ 1117.205416] GPR08: c09926ec 00000000 00000000 3ffff000 24082224 [ 1117.206106] NIP [c010dbec] copy_from_kernel_nofault+0x70/0x1c0 [ 1117.206202] LR [c010dbac] copy_from_kernel_nofault+0x30/0x1c0 [ 1117.206258] --- interrupt: 301 [ 1117.206372] [cacdbd38] [c004bbb0] kthread_probe_data+0x44/0x70 (unreliable) [ 1117.206561] [cacdbd58] [c0045948] print_worker_info+0xe0/0x194 [ 1117.206717] [cacdbdb8] [c00548ac] sched_show_task+0x134/0x168 [ 1117.206851] [cacdbdd8] [c005a268] show_state_filter+0x70/0x100 [ 1117.206989] [cacdbe08] [c039baa0] sysrq_handle_showstate+0x14/0x24 [ 1117.207122] [cacdbe18] [c039bf18] __handle_sysrq+0xac/0x1d0 [ 1117.207257] [cacdbe48] [c039c0c0] write_sysrq_trigger+0x4c/0x74 [ 1117.207407] [cacdbe68] [c01fba48] proc_reg_write+0xb4/0x114 [ 1117.207550] [cacdbe88] [c0179968] vfs_write+0x12c/0x478 [ 1117.207686] [cacdbf08] [c0179e60] ksys_write+0x78/0x128 [ 1117.207826] [cacdbf38] [c00110d0] ret_from_syscall+0x0/0x34 [ 1117.207938] --- interrupt: c01 at 0xfd4e784 [ 1117.208008] NIP: 0fd4e784 LR: 0fe0f244 CTR: 10048d38 [ 1117.208083] REGS: cacdbf48 TRAP: 0c01 Tainted: G W (5.10.0-rc5-01340-g83f53be2de31-dirty) [ 1117.208134] MSR: 0000d032 <EE,PR,ME,IR,DR,RI> CR: 44002222 XER: 00000000 [ 1117.208470] [ 1117.208470] GPR00: 00000004 7fc34090 77bfb4e0 00000001 1080fa40 00000002 7400000f fefefeff [ 1117.208470] GPR08: 7f7f7f7f 10048d38 1080c414 7fc343c0 00000000 [ 1117.209104] NIP [0fd4e784] 0xfd4e784 [ 1117.209180] LR [0fe0f244] 0xfe0f244 [ 1117.209236] --- interrupt: c01 [ 1117.209274] Instruction dump: [ 1117.209353] 714a4000 418200f0 73ca0001 40820084 73ca0032 408200f8 73c90040 4082ff60 [ 1117.209727] 0fe00000 3c60c082 386399f4 48013b65 <0fe00000> 80010034 3860000b 7c0803a6 [ 1117.210102] ---[ end trace 1927c0323393af3e ]--- To avoid that, copy_from_kernel_nofault_allowed() is used to check whether the address is a valid kernel address. But the default version of it returns true for any address. Provide a powerpc version of copy_from_kernel_nofault_allowed() that returns false when the address is below TASK_USER_MAX, so that copy_from_kernel_nofault() will return -ERANGE. Fixes: c33165253492 ("powerpc: use non-set_fs based maccess routines") Reported-by: Qian Cai <[email protected]> Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/18bcb456d32a3e74f5ae241fd6f1580c092d07f5.1607360230.git.christophe.leroy@csgroup.eu
2020-12-07powerpc/powernv/idle: Restore CIABR after idle for Power9Jordan Niethe1-0/+3
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 <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]