kernel/linux.git/arch/powerpc/sysdev/xive/common.c, branch v5.15.208

powerpc/xive: Change IRQ domain to a tree domain

2021-11-25T08:48:44+00:00

commit 8e80a73fa9a7747e3e8255cb149c543aabf65a24 upstream. Commit 4f86a06e2d6e ("irqdomain: Make normal and nomap irqdomains exclusive") introduced an IRQ_DOMAIN_FLAG_NO_MAP flag to isolate the 'nomap' domains still in use under the powerpc arch. With this new flag, the revmap_tree of the IRQ domain is not used anymore. This change broke the support of shared LSIs [1] in the XIVE driver because it was relying on a lookup in the revmap_tree to query previously mapped interrupts. Linux now creates two distinct IRQ mappings on the same HW IRQ which can lead to unexpected behavior in the drivers. The XIVE IRQ domain is not a direct mapping domain and its HW IRQ interrupt number space is rather large : 1M/socket on POWER9 and POWER10, change the XIVE driver to use a 'tree' domain type instead. [1] For instance, a linux KVM guest with virtio-rng and virtio-balloon devices. Fixes: 4f86a06e2d6e ("irqdomain: Make normal and nomap irqdomains exclusive") Cc: stable@vger.kernel.org # v5.14+ Signed-off-by: Cédric Le Goater Tested-by: Greg Kurz Acked-by: Marc Zyngier Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211116134022.420412-1-clg@kaod.org Signed-off-by: Greg Kroah-Hartman

powerpc/xive: Discard disabled interrupts in get_irqchip_state()

2021-10-13T05:38:55+00:00

When an interrupt is passed through, the KVM XIVE device calls the set_vcpu_affinity() handler which raises the P bit to mask the interrupt and to catch any in-flight interrupts while routing the interrupt to the guest. On the guest side, drivers (like some Intels) can request at probe time some MSIs and call synchronize_irq() to check that there are no in flight interrupts. This will call the XIVE get_irqchip_state() handler which will always return true as the interrupt P bit has been set on the host side and lock the CPU in an infinite loop. Fix that by discarding disabled interrupts in get_irqchip_state(). Fixes: da15c03b047d ("powerpc/xive: Implement get_irqchip_state method for XIVE to fix shutdown race") Cc: stable@vger.kernel.org #v5.4+ Signed-off-by: Cédric Le Goater Tested-by: seeteena Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211011070203.99726-1-clg@kaod.org

Merge branch 'fixes' into next

2021-09-03T12:54:12+00:00

Merge our fixes branch into next. That lets us resolve a conflict in arch/powerpc/sysdev/xive/common.c. Between cbc06f051c52 ("powerpc/xive: Do not skip CPU-less nodes when creating the IPIs"), which moved request_irq() out of xive_init_ipis(), and 17df41fec5b8 ("powerpc: use IRQF_NO_DEBUG for IPIs") which added IRQF_NO_DEBUG to that request_irq() call, which has now moved.

powerpc/xive: Do not mark xive_request_ipi() as __init

2021-08-18T13:52:13+00:00

Compiling ppc64le_defconfig with clang-14 shows a modpost warning: WARNING: modpost: vmlinux.o(.text+0xa74e0): Section mismatch in reference from the function xive_setup_cpu_ipi() to the function .init.text:xive_request_ipi() The function xive_setup_cpu_ipi() references the function __init xive_request_ipi(). This is often because xive_setup_cpu_ipi lacks a __init annotation or the annotation of xive_request_ipi is wrong. xive_request_ipi() is called from xive_setup_cpu_ipi(), which is not __init, so xive_request_ipi() should not be marked __init. Remove the attribute so there is no more warning. Fixes: cbc06f051c52 ("powerpc/xive: Do not skip CPU-less nodes when creating the IPIs") Signed-off-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210816185711.21563-1-nathan@kernel.org

powerpc: rename powerpc_debugfs_root to arch_debugfs_dir

2021-08-13T12:04:26+00:00

No functional change in this patch. arch_debugfs_dir is the generic kernel name declared in linux/debugfs.h for arch-specific debugfs directory. Architectures like x86/s390 already use the name. Rename powerpc specific powerpc_debugfs_root to arch_debugfs_dir. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210812132831.233794-2-aneesh.kumar@linux.ibm.com

powerpc/xive: Do not skip CPU-less nodes when creating the IPIs

2021-08-12T12:31:41+00:00

On PowerVM, CPU-less nodes can be populated with hot-plugged CPUs at runtime. Today, the IPI is not created for such nodes, and hot-plugged CPUs use a bogus IPI, which leads to soft lockups. We can not directly allocate and request the IPI on demand because bringup_up() is called under the IRQ sparse lock. The alternative is to allocate the IPIs for all possible nodes at startup and to request the mapping on demand when the first CPU of a node is brought up. Fixes: 7dcc37b3eff9 ("powerpc/xive: Map one IPI interrupt per node") Cc: stable@vger.kernel.org # v5.13 Reported-by: Geetika Moolchandani Signed-off-by: Cédric Le Goater Tested-by: Srikar Dronamraju Tested-by: Laurent Vivier Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210807072057.184698-1-clg@kaod.org

powerpc: use IRQF_NO_DEBUG for IPIs

2021-08-10T13:15:01+00:00

There is no need to use the lockup detector ("noirqdebug") for IPIs. The ipistorm benchmark measures a ~10% improvement on high systems when this flag is set. Signed-off-by: Cédric Le Goater Reviewed-by: Thomas Gleixner Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210719130614.195886-1-clg@kaod.org

powerpc/xive: Use XIVE domain under xmon and debugfs

2021-08-10T13:15:01+00:00

The default domain of the PCI/MSIs is not the XIVE domain anymore. To list the IRQ mappings under XMON and debugfs, query the IRQ data from the low level XIVE domain. Signed-off-by: Cédric Le Goater Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210701132750.1475580-32-clg@kaod.org

powerpc/pseries/pci: Add a msi_free() handler to clear XIVE data

2021-08-10T13:14:58+00:00

The MSI domain clears the IRQ with msi_domain_free(), which calls irq_domain_free_irqs_top(), which clears the handler data. This is a problem for the XIVE controller since we need to unmap MMIO pages and free a specific XIVE structure. The 'msi_free()' handler is called before irq_domain_free_irqs_top() when the handler data is still available. Use that to clear the XIVE controller data. Signed-off-by: Cédric Le Goater Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210701132750.1475580-10-clg@kaod.org

powerpc/xive: Remove irqd_is_started() check when setting the affinity

2021-08-10T13:14:57+00:00

In the early days of XIVE support, commit cffb717ceb8e ("powerpc/xive: Ensure active irqd when setting affinity") tried to fix an issue related to interrupt migration. If the root cause was related to CPU unplug, it should have been fixed and there is no reason to keep the irqd_is_started() check. This test is also breaking affinity setting of MSIs which can set before starting the associated IRQ. Signed-off-by: Cédric Le Goater Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210701132750.1475580-8-clg@kaod.org