kernel/arch/powerpc/platforms/pseries/vas.c, branch linux-6.2.y

powerpc/pseries/vas: Ignore VAS update for DLPAR if copy/paste is not enabled

2023-04-06T10:12:44Z

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 Reviewed-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://msgid.link/1d0e727e7dbd9a28627ef08ca9df9c86a50175e2.camel@linux.ibm.com Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Use lparcfg to reconfig VAS windows for DLPAR CPU

2022-10-18T11:46:18Z

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 [mpe: Rework error handling, report any errors as EIO] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/efa9c16e4a78dda4567a16f13dabfd73cb4674a2.camel@linux.ibm.com

powerpc/pseries/vas: Add VAS IRQ primary handler

2022-10-18T11:46:18Z

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 Reviewed-by: Frederic Barrat Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/aaad8813b4762a6753cfcd0b605a7574a5192ec7.camel@linux.ibm.com

powerpc/pseries/vas: Pass hw_cpu_id to node associativity HCALL

2022-09-30T08:35:51Z

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 Signed-off-by: Haren Myneni [mpe: Update change log to mention Linux vs HV CPU numbers] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/55380253ea0c11341824cd4c0fc6bbcfc5752689.camel@linux.ibm.com

powerpc/pseries/vas: Remove the unneeded result variable

2022-09-28T09:22:14Z

Return the value vas_register_coproc_api() directly instead of storing it in another redundant variable. Reported-by: Zeal Robot Signed-off-by: ye xingchen Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220825072657.229168-1-ye.xingchen@zte.com.cn

powerpc/pseries/vas: Fix comment typo

2022-07-28T06:22:14Z

The double `the' in line 807 is duplicated, remove one. Signed-off-by: Jason Wang Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220718075553.70897-1-wangborong@cdjrlc.com

powerpc: Include asm/firmware.h in all users of firmware_has_feature()

2022-06-29T06:45:05Z

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 Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/11956ec181a034b51a881ac9c059eea72c679a73.1651828453.git.christophe.leroy@csgroup.eu

Merge branch 'fixes' into next

2022-05-18T14:11:51Z

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.

powerpc: fix typos in comments

2022-05-05T12:12:44Z

Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall Reviewed-by: Joel Stanley Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220430185654.5855-1-Julia.Lawall@inria.fr

powerpc/pseries/vas: Use QoS credits from the userspace

2022-05-04T12:00:47Z

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 Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/76d156f8af1e03cc09369d68e0bfad0c40031bcc.camel@linux.ibm.com