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path: root/arch/powerpc/platforms/pseries/vas.c
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2023-08-03powerpc/pseries/vas: Hold mmap_mutex after mmap lock during window closeHaren Myneni1-2/+7
[ Upstream commit b59c9dc4d9d47b3c4572d826603fde507055b656 ] Commit 8ef7b9e1765a ("powerpc/pseries/vas: Close windows with DLPAR core removal") unmaps the window paste address and issues HCALL to close window in the hypervisor for migration or DLPAR core removal events. So holds mmap_mutex and then mmap lock before unmap the paste address. But if the user space issue mmap paste address at the same time with the migration event, coproc_mmap() is called after holding the mmap lock which can trigger deadlock when trying to acquire mmap_mutex in coproc_mmap(). t1: mmap() call to mmap t2: Migration event window paste address do_mmap2() migration_store() ksys_mmap_pgoff() pseries_migrate_partition() vm_mmap_pgoff() vas_migration_handler() Acquire mmap lock reconfig_close_windows() do_mmap() lock mmap_mutex mmap_region() Acquire mmap lock call_mmap() //Wait for mmap lock coproc_mmap() unmap vma lock mmap_mutex update window status //wait for mmap_mutex Release mmap lock mmap vma unlock mmap_mutex update window status unlock mmap_mutex ... Release mmap lock Fix this deadlock issue by holding mmap lock first before mmap_mutex in reconfig_close_windows(). Fixes: 8ef7b9e1765a ("powerpc/pseries/vas: Close windows with DLPAR core removal") Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230716100506.7833-1-haren@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19powerpc/64s: Fix VAS mm use after freeNicholas Piggin1-1/+1
[ Upstream commit b4bda59b47879cce38a6ec5a01cd3cac702b5331 ] The refcount on mm is dropped before the coprocessor is detached. Reported-by: Sachin Sant <sachinp@linux.ibm.com> Fixes: 7bc6f71bdff5f ("powerpc/vas: Define and use common vas_window struct") Fixes: b22f2d88e435c ("powerpc/pseries/vas: Integrate API with open/close windows") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Sachin Sant <sachinp@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230607101024.14559-1-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-06powerpc/pseries/vas: Ignore VAS update for DLPAR if copy/paste is not enabledHaren Myneni1-0/+8
commit eca9f6e6f83b6725b84e1c76fdde19b003cff0eb upstream. The hypervisor supports user-mode NX from Power10. pseries_vas_dlpar_cpu() is called from lparcfg_write() to update VAS windows for DLPAR event in shared processor mode and the kernel gets -ENOTSUPP for HCALLs if the user-mode NX is not supported. The current VAS implementation also supports only with Radix page tables. Whereas in dedicated processor mode, pseries_vas_notifier() is registered only if the copy/paste feature is enabled. So instead of displaying HCALL error messages, update VAS capabilities if the copy/paste feature is available. This patch ignores updating VAS capabilities in pseries_vas_dlpar_cpu() and returns success if the copy/paste feature is not enabled. Then lparcfg_write() completes the processor DLPAR operations without any failures. Fixes: 2147783d6bf0 ("powerpc/pseries: Use lparcfg to reconfig VAS windows for DLPAR CPU") Cc: stable@vger.kernel.org # v6.1+ Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/1d0e727e7dbd9a28627ef08ca9df9c86a50175e2.camel@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-18powerpc/pseries: Use lparcfg to reconfig VAS windows for DLPAR CPUHaren Myneni1-14/+29
The hypervisor assigns VAS (Virtual Accelerator Switchboard) windows depends on cores configured in LPAR. The kernel uses OF reconfig notifier to reconfig VAS windows for DLPAR CPU event. In the case of shared CPU mode partition, the hypervisor assigns VAS windows depends on CPU entitled capacity, not based on vcpus. When the user changes CPU entitled capacity for the partition, drmgr uses /proc/ppc64/lparcfg interface to notify the kernel. This patch adds the following changes to update VAS resources for shared mode: - Call vas reconfig windows from lparcfg_write() - Ignore reconfig changes in the VAS notifier Signed-off-by: Haren Myneni <haren@linux.ibm.com> [mpe: Rework error handling, report any errors as EIO] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/efa9c16e4a78dda4567a16f13dabfd73cb4674a2.camel@linux.ibm.com
2022-10-18powerpc/pseries/vas: Add VAS IRQ primary handlerHaren Myneni1-7/+33
irq_default_primary_handler() can be used only with IRQF_ONESHOT flag, but the flag disables IRQ before executing the thread handler and enables it after the interrupt is handled. But this IRQ disable sets the VAS IRQ OFF state in the hypervisor. In case if NX faults during this window, the hypervisor will not deliver the fault interrupt to the partition and the user space may wait continuously for the CSB update. So use VAS specific IRQ handler instead of calling the default primary handler. Increment pending_faults counter in IRQ handler and the bottom thread handler will process all faults based on this counter. In case if the another interrupt is received while the thread is running, it will be processed using this counter. The synchronization of top and bottom handlers will be done with IRQTF_RUNTHREAD flag and will re-enter to bottom half if this flag is set. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/aaad8813b4762a6753cfcd0b605a7574a5192ec7.camel@linux.ibm.com
2022-09-30powerpc/pseries/vas: Pass hw_cpu_id to node associativity HCALLHaren Myneni1-1/+1
Generally the hypervisor decides to allocate a window on different VAS instances. But if user space wishes to allocate on the current VAS instance where the process is executing, the kernel has to pass associativity domain IDs to allocate VAS window HCALL. To determine the associativity domain IDs for the current CPU, smp_processor_id() is passed to node associativity HCALL which may return H_P2 (-55) error during DLPAR CPU event. This is because Linux CPU numbers (smp_processor_id()) are not the same as the hypervisor's view of CPU numbers. Fix the issue by passing hard_smp_processor_id() with VPHN_FLAG_VCPU flag (PAPR 14.11.6.1 H_HOME_NODE_ASSOCIATIVITY). Fixes: b22f2d88e435 ("powerpc/pseries/vas: Integrate API with open/close windows") Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Haren Myneni <haren@linux.ibm.com> [mpe: Update change log to mention Linux vs HV CPU numbers] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/55380253ea0c11341824cd4c0fc6bbcfc5752689.camel@linux.ibm.com
2022-09-28powerpc/pseries/vas: Remove the unneeded result variableye xingchen1-5/+1
Return the value vas_register_coproc_api() directly instead of storing it in another redundant variable. Reported-by: Zeal Robot <zealci@zte.com.cn> Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220825072657.229168-1-ye.xingchen@zte.com.cn
2022-07-28powerpc/pseries/vas: Fix comment typoJason Wang1-1/+1
The double `the' in line 807 is duplicated, remove one. Signed-off-by: Jason Wang <wangborong@cdjrlc.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220718075553.70897-1-wangborong@cdjrlc.com
2022-06-29powerpc: Include asm/firmware.h in all users of firmware_has_feature()Christophe Leroy1-0/+1
Trying to remove asm/ppc_asm.h from all places that don't need it leads to several failures linked to firmware_has_feature(). To fix it, include asm/firmware.h in all files using firmware_has_feature() All users found with: git grep -L "firmware\.h" ` git grep -l "firmware_has_feature("` Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/11956ec181a034b51a881ac9c059eea72c679a73.1651828453.git.christophe.leroy@csgroup.eu
2022-05-18Merge branch 'fixes' into nextMichael Ellerman1-11/+12
Merge our fixes branch from this cycle. In particular this brings in a papr_scm.c change which a subsequent patch has a dependency on.
2022-05-05powerpc: fix typos in commentsJulia Lawall1-1/+1
Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220430185654.5855-1-Julia.Lawall@inria.fr
2022-05-04powerpc/pseries/vas: Use QoS credits from the userspaceHaren Myneni1-11/+12
The user can change the QoS credits dynamically with the management console interface which notifies OS with sysfs. After returning from the OS interface successfully, the management console updates the hypervisor. Since the VAS capabilities in the hypervisor is not updated when the OS gets the update, the kernel is using the old total credits value from the hypervisor. Fix this issue by using the new QoS credits from the userspace instead of depending on VAS capabilities from the hypervisor. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/76d156f8af1e03cc09369d68e0bfad0c40031bcc.camel@linux.ibm.com
2022-03-07powerpc/pseries/vas: Add VAS migration handlerHaren Myneni1-1/+97
Since the VAS windows belong to the VAS hardware resource, the hypervisor expects the partition to close them on source partition and reopen them after the partition migrated on the destination machine. This handler is called before pseries_suspend() to close these windows and again invoked after migration. All active windows for both default and QoS types will be closed and mark them inactive and reopened after migration with this handler. During the migration, the user space receives paste instruction failure if it issues copy/paste on these inactive windows. The current migration implementation does not freeze the user space and applications can continue to open VAS windows while migration is in progress. So when the migration_in_progress flag is set, VAS open window API returns -EBUSY. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/05e45ff4f8babd2490ccb7ae923884f4aa21a7e5.camel@linux.ibm.com
2022-03-07powerpc/pseries/vas: Modify reconfig open/close functions for migrationHaren Myneni1-17/+71
VAS is a hardware engine stays on the chip. So when the partition migrates, all VAS windows on the source system have to be closed and reopen them on the destination after migration. The kernel has to consider both DLPAR CPU and migration events to take action on VAS windows. So using VAS_WIN_NO_CRED_CLOSE and VAS_WIN_MIGRATE_CLOSE status bits and windows will be reopened after migration only after both status bits are cleared. This patch make changes to the current reconfig_open/close_windows functions to support migration: - Set VAS_WIN_MIGRATE_CLOSE to the window status when closes and reopen windows with the same status during resume. - Continue to close all windows even if deallocate HCALL failed (should not happen) since no way to stop migration with the current LPM implementation. - If the DLPAR CPU event happens while migration is in progress, set VAS_WIN_NO_CRED_CLOSE to the window status. Close window happens with the first event (migration or DLPAR) and Reopen window happens only with the last event (migration or DLPAR). Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0aad580387cb58379496b4cbbd7c5596e9ea70be.camel@linux.ibm.com
2022-03-07powerpc/pseries/vas: Define global hv_cop_caps structHaren Myneni1-27/+20
The coprocessor capabilities struct is used to get default and QoS capabilities from the hypervisor during init, DLPAR event and migration. So instead of allocating this struct for each event, define global struct and reuse it which allows the migration code to avoid adding an error path. Also disable copy/paste feature flag if any capabilities HCALL is failed. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/57da6a270fcb9308cd57be7c88037029343080f7.camel@linux.ibm.com
2022-03-07powerpc/pseries/vas: Add 'update_total_credits' entry for QoS capabilitiesHaren Myneni1-1/+1
pseries supports two types of credits - Default (uses normal priority FIFO) and Qality of service (QoS uses high priority FIFO). The user decides the number of QoS credits and sets this value with HMC interface. The total credits for QoS capabilities can be changed dynamically with HMC interface which invokes drmgr to communicate to the kernel. This patch creats 'update_total_credits' entry for QoS capabilities so that drmgr command can write the new target QoS credits in sysfs. Instead of using this value, the kernel gets the new QoS capabilities from the hypervisor whenever update_total_credits is updated to make sure sync with the QoS target credits in the hypervisor. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b01ef31a0f964686d00243e7de7f09c73c07e69e.camel@linux.ibm.com
2022-03-07powerpc/pseries/vas: sysfs interface to export capabilitiesHaren Myneni1-0/+6
The hypervisor provides the available VAS GZIP capabilities such as default or QoS window type and the target available credits in each type. This patch creates sysfs entries and exports the target, used and the available credits for each feature. This interface can be used by the user space to determine the credits usage or to set the target credits in the case of QoS type (for DLPAR). /sys/devices/vas/vas0/gzip/default_capabilities (default GZIP capabilities) nr_total_credits /* Total credits available. Can be /* changed with DLPAR operation */ nr_used_credits /* Used credits */ /sys/devices/vas/vas0/gzip/qos_capabilities (QoS GZIP capabilities) nr_total_credits nr_used_credits Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/702d8b626ebfac2b52f4995eebeafe1c9a6fcb75.camel@linux.ibm.com
2022-03-07powerpc/pseries/vas: Reopen windows with DLPAR core addHaren Myneni1-1/+90
VAS windows can be closed in the hypervisor due to lost credits when the core is removed and the kernel gets fault for NX requests on these inactive windows. If the NX requests are issued on these inactive windows, OS gets page faults and the paste failure will be returned to the user space. If the lost credits are available later with core add, reopen these windows and set them active. Later when the OS sees page faults on these active windows, it creates mapping on the new paste address. Then the user space can continue to use these windows and send HW compression requests to NX successfully. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d9f360e21355e6826142c81146acfa9b60bc7ecc.camel@linux.ibm.com
2022-03-07powerpc/pseries/vas: Close windows with DLPAR core removalHaren Myneni1-8/+199
The hypervisor assigns vas credits (windows) for each LPAR based on the number of cores configured in that system. The OS is expected to release credits when cores are removed, and may allocate more when cores are added. So there is a possibility of using excessive credits (windows) in the LPAR and the hypervisor expects the system to close the excessive windows so that NX load can be equally distributed across all LPARs in the system. When the OS closes the excessive windows in the hypervisor, it sets the window status inactive and invalidates window virtual address mapping. The user space receives paste instruction failure if any NX requests are issued on the inactive window. Then the user space can use with the available open windows or retry NX requests until this window active again. This patch also adds the notifier for core removal/add to close windows in the hypervisor if the system lost credits (core removal) and reopen windows in the hypervisor when the previously lost credits are available. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/108928f9c00a48cc6a722315d482d07cf66acf5a.camel@linux.ibm.com
2022-03-07powerpc/pseries/vas: Save PID in pseries_vas_window structHaren Myneni1-4/+5
The kernel sets the VAS window with PID when it is opened in the hypervisor. During DLPAR operation, windows can be closed and reopened in the hypervisor when the credit is available. So saves this PID in pseries_vas_window struct when the window is opened initially and reuse it later during DLPAR operation. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a57cbe6d292fe49ad55a0b49c5679d6a24d8fe73.camel@linux.ibm.com
2022-03-07powerpc/pseries/vas: Use common names in VAS capability structureHaren Myneni1-5/+5
nr_total/nr_used_credits provides credits usage to user space via sysfs and the same interface can be used on PowerNV in future. Changed with proper naming so that applicable on both pseries and PowerNV. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f4313e9f198ee4f8d4fa4d015d8d1873e17851e6.camel@linux.ibm.com
2021-12-23powerpc/pseries: Add __init attribute to eligible functionsNick Child1-1/+1
Some functions defined in 'arch/powerpc/platforms/pseries' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by: Nick Child <nick.child@ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211216220035.605465-13-nick.child@ibm.com
2021-12-16powerpc/pseries/vas: Don't print an error when VAS is unavailableNicholas Piggin1-2/+9
KVM does not support VAS so guests always print a useless error on boot vas: HCALL(398) error -2, query_type 0, result buffer 0x57f2000 Change this to only print the message if the error is not H_FUNCTION. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211126052133.1664375-1-npiggin@gmail.com
2021-08-20powerpc/pseries/vas: Declare pseries_vas_fault_thread_fn() as staticCédric Le Goater1-1/+1
This fixes a compile error with W=1. Fixes: 6d0aaf5e0de0 ("powerpc/pseries/vas: Setup IRQ and fault handling") Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210819125656.14498-3-clg@kaod.org
2021-06-25powerpc/pseries/vas: Include irqdomain.hMichael Ellerman1-0/+1
There are patches in flight to break the dependency between asm/irq.h and linux/irqdomain.h, which would break compilation of vas.c because it needs the declaration of irq_create_mapping() etc. So add an explicit include of irqdomain.h to avoid that becoming a problem in future. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210625045337.3197833-1-mpe@ellerman.id.au
2021-06-20powerpc/pseries/vas: Setup IRQ and fault handlingHaren Myneni1-0/+102
NX generates an interrupt when sees a fault on the user space buffer and the hypervisor forwards that interrupt to OS. Then the kernel handles the interrupt by issuing H_GET_NX_FAULT hcall to retrieve the fault CRB information. This patch also adds changes to setup and free IRQ per each window and also handles the fault by updating the CSB. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b8fc66dcb783d06a099a303e5cfc69087bb3357a.camel@linux.ibm.com
2021-06-20powerpc/pseries/vas: Integrate API with open/close windowsHaren Myneni1-0/+223
This patch adds VAS window allocatioa/close with the corresponding hcalls. Also changes to integrate with the existing user space VAS API and provide register/unregister functions to NX pseries driver. The driver register function is used to create the user space interface (/dev/crypto/nx-gzip) and unregister to remove this entry. The user space process opens this device node and makes an ioctl to allocate VAS window. The close interface is used to deallocate window. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e8d956bace3f182c4d2e66e343ff37cb0391d1fd.camel@linux.ibm.com
2021-06-20powerpc/pseries/vas: Implement getting capabilities from hypervisorHaren Myneni1-0/+122
The hypervisor provides VAS capabilities for GZIP default and QoS features. These capabilities gives information for the specific features such as total number of credits available in LPAR, maximum credits allowed per window, maximum credits allowed in LPAR, whether usermode copy/paste is supported, and etc. This patch adds the following: - Retrieve all features that are provided by hypervisor using H_QUERY_VAS_CAPABILITIES hcall with 0 as feature type. - Retrieve capabilities for the specific feature using the same hcall and the feature type (1 for QoS and 2 for default type). Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/177c88608cb88f7b87d1c546103f18cec6c056b4.camel@linux.ibm.com
2021-06-20powerpc/pseries/vas: Add hcall wrappers for VAS handlingHaren Myneni1-0/+147
This patch adds the following hcall wrapper functions to allocate, modify and deallocate VAS windows, and retrieve VAS capabilities. H_ALLOCATE_VAS_WINDOW: Allocate VAS window H_DEALLOCATE_VAS_WINDOW: Close VAS window H_MODIFY_VAS_WINDOW: Setup window before using H_QUERY_VAS_CAPABILITIES: Get VAS capabilities Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/40fb02a4d56ca4e240b074a15029082055be5997.camel@linux.ibm.com
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