BMC/Intel-BMC/linux.git/drivers/pci/msi.c, branch dev-5.2

PCI: Add pci_dev_id() helper

2019-04-29T21:12:05+00:00

In several places in the kernel we find PCI_DEVID used like this: PCI_DEVID(dev->bus->number, dev->devfn) Add a "pci_dev_id(struct pci_dev *dev)" helper to simplify callers. Signed-off-by: Heiner Kallweit Signed-off-by: Bjorn Helgaas

PCI/MSI: Remove obsolete sanity checks for multiple interrupt sets

2019-02-18T10:21:29+00:00

Multiple interrupt sets for affinity spreading are now handled in the core code and the number of sets and their size is recalculated via a driver supplied callback. That avoids the requirement to invoke pci_alloc_irq_vectors_affinity() with the arguments minvecs and maxvecs set to the same value and the callsite handling the ENOSPC situation. Remove the now obsolete sanity checks and the related comments. Signed-off-by: Thomas Gleixner Reviewed-by: Ming Lei Acked-by: Marc Zyngier Cc: Christoph Hellwig Cc: Bjorn Helgaas Cc: Jens Axboe Cc: linux-block@vger.kernel.org Cc: Sagi Grimberg Cc: linux-nvme@lists.infradead.org Cc: linux-pci@vger.kernel.org Cc: Keith Busch Cc: Sumit Saxena Cc: Kashyap Desai Cc: Shivasharan Srikanteshwara Link: https://lkml.kernel.org/r/20190216172228.778630549@linutronix.de

genirq/affinity: Add new callback for (re)calculating interrupt sets

2019-02-18T10:21:28+00:00

The interrupt affinity spreading mechanism supports to spread out affinities for one or more interrupt sets. A interrupt set contains one or more interrupts. Each set is mapped to a specific functionality of a device, e.g. general I/O queues and read I/O queus of multiqueue block devices. The number of interrupts per set is defined by the driver. It depends on the total number of available interrupts for the device, which is determined by the PCI capabilites and the availability of underlying CPU resources, and the number of queues which the device provides and the driver wants to instantiate. The driver passes initial configuration for the interrupt allocation via a pointer to struct irq_affinity. Right now the allocation mechanism is complex as it requires to have a loop in the driver to determine the maximum number of interrupts which are provided by the PCI capabilities and the underlying CPU resources. This loop would have to be replicated in every driver which wants to utilize this mechanism. That's unwanted code duplication and error prone. In order to move this into generic facilities it is required to have a mechanism, which allows the recalculation of the interrupt sets and their size, in the core code. As the core code does not have any knowledge about the underlying device, a driver specific callback is required in struct irq_affinity, which can be invoked by the core code. The callback gets the number of available interupts as an argument, so the driver can calculate the corresponding number and size of interrupt sets. At the moment the struct irq_affinity pointer which is handed in from the driver and passed through to several core functions is marked 'const', but for the callback to be able to modify the data in the struct it's required to remove the 'const' qualifier. Add the optional callback to struct irq_affinity, which allows drivers to recalculate the number and size of interrupt sets and remove the 'const' qualifier. For simple invocations, which do not supply a callback, a default callback is installed, which just sets nr_sets to 1 and transfers the number of spreadable vectors to the set_size array at index 0. This is for now guarded by a check for nr_sets != 0 to keep the NVME driver working until it is converted to the callback mechanism. To make sure that the driver configuration is correct under all circumstances the callback is invoked even when there are no interrupts for queues left, i.e. the pre/post requirements already exhaust the numner of available interrupts. At the PCI layer irq_create_affinity_masks() has to be invoked even for the case where the legacy interrupt is used. That ensures that the callback is invoked and the device driver can adjust to that situation. [ tglx: Fixed the simple case (no sets required). Moved the sanity check for nr_sets after the invocation of the callback so it catches broken drivers. Fixed the kernel doc comments for struct irq_affinity and de-'This patch'-ed the changelog ] Signed-off-by: Ming Lei Signed-off-by: Thomas Gleixner Acked-by: Marc Zyngier Cc: Christoph Hellwig Cc: Bjorn Helgaas Cc: Jens Axboe Cc: linux-block@vger.kernel.org Cc: Sagi Grimberg Cc: linux-nvme@lists.infradead.org Cc: linux-pci@vger.kernel.org Cc: Keith Busch Cc: Sumit Saxena Cc: Kashyap Desai Cc: Shivasharan Srikanteshwara Link: https://lkml.kernel.org/r/20190216172228.512444498@linutronix.de

PCI/MSI: Return -ENOSPC from pci_alloc_irq_vectors_affinity()

2019-01-15T23:31:29+00:00

The API of pci_alloc_irq_vectors_affinity() says it returns -ENOSPC if fewer than @min_vecs interrupt vectors are available for @dev. However, if a device supports MSI-X but not MSI and a caller requests @min_vecs that can't be satisfied by MSI-X, we previously returned -EINVAL (from the failed attempt to enable MSI), not -ENOSPC. When -ENOSPC is returned, callers may reduce the number IRQs they request and try again. Most callers can use the @min_vecs and @max_vecs parameters to avoid this retry loop, but that doesn't work when using IRQ affinity "nr_sets" because rebalancing the sets is driver-specific. This return value bug has been present since pci_alloc_irq_vectors() was added in v4.10 by aff171641d18 ("PCI: Provide sensible IRQ vector alloc/free routines"), but it wasn't an issue because @min_vecs/@max_vecs removed the need for callers to iteratively reduce the number of IRQs requested and retry the allocation, so they didn't need to distinguish -ENOSPC from -EINVAL. In v5.0, 6da4b3ab9a6e ("genirq/affinity: Add support for allocating interrupt sets") added IRQ sets to the interface, which reintroduced the need to check for -ENOSPC and possibly reduce the number of IRQs requested and retry the allocation. Signed-off-by: Ming Lei [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas Cc: Jens Axboe Cc: Keith Busch Cc: Christoph Hellwig

genirq/core: Introduce struct irq_affinity_desc

2018-12-19T10:32:08+00:00

The interrupt affinity management uses straight cpumask pointers to convey the automatically assigned affinity masks for managed interrupts. The core interrupt descriptor allocation also decides based on the pointer being non NULL whether an interrupt is managed or not. Devices which use managed interrupts usually have two classes of interrupts: - Interrupts for multiple device queues - Interrupts for general device management Currently both classes are treated the same way, i.e. as managed interrupts. The general interrupts get the default affinity mask assigned while the device queue interrupts are spread out over the possible CPUs. Treating the general interrupts as managed is both a limitation and under certain circumstances a bug. Assume the following situation: default_irq_affinity = 4..7 So if CPUs 4-7 are offlined, then the core code will shut down the device management interrupts because the last CPU in their affinity mask went offline. It's also a limitation because it's desired to allow manual placement of the general device interrupts for various reasons. If they are marked managed then the interrupt affinity setting from both user and kernel space is disabled. To remedy that situation it's required to convey more information than the cpumasks through various interfaces related to interrupt descriptor allocation. Instead of adding yet another argument, create a new data structure 'irq_affinity_desc' which for now just contains the cpumask. This struct can be expanded to convey auxilliary information in the next step. No functional change, just preparatory work. [ tglx: Simplified logic and clarified changelog ] Suggested-by: Thomas Gleixner Suggested-by: Bjorn Helgaas Signed-off-by: Dou Liyang Signed-off-by: Thomas Gleixner Cc: linux-pci@vger.kernel.org Cc: kashyap.desai@broadcom.com Cc: shivasharan.srikanteshwara@broadcom.com Cc: sumit.saxena@broadcom.com Cc: ming.lei@redhat.com Cc: hch@lst.de Cc: douliyang1@huawei.com Link: https://lkml.kernel.org/r/20181204155122.6327-2-douliyangs@gmail.com

genirq/affinity: Add support for allocating interrupt sets

2018-11-05T11:16:27+00:00

A driver may have a need to allocate multiple sets of MSI/MSI-X interrupts, and have them appropriately affinitized. Add support for defining a number of sets in the irq_affinity structure, of varying sizes, and get each set affinitized correctly across the machine. [ tglx: Minor changelog tweaks ] Signed-off-by: Jens Axboe Signed-off-by: Ming Lei Signed-off-by: Thomas Gleixner Reviewed-by: Hannes Reinecke Reviewed-by: Ming Lei Reviewed-by: Keith Busch Reviewed-by: Sagi Grimberg Cc: linux-block@vger.kernel.org Link: https://lkml.kernel.org/r/20181102145951.31979-5-ming.lei@redhat.com

PCI/MSI: Warn and return error if driver enables MSI/MSI-X twice

2018-09-25T20:17:39+00:00

It is a serious driver defect to enable MSI or MSI-X more than once. Doing so may panic the kernel as in the stack trace below: Call Trace: sysfs_add_one+0xa5/0xd0 create_dir+0x7c/0xe0 sysfs_create_subdir+0x1c/0x20 internal_create_group+0x6d/0x290 sysfs_create_groups+0x4a/0xa0 populate_msi_sysfs+0x1cd/0x210 pci_enable_msix+0x31c/0x3e0 igbuio_pci_open+0x72/0x300 [igb_uio] uio_open+0xcc/0x120 [uio] chrdev_open+0xa1/0x1e0 [...] do_sys_open+0xf3/0x1f0 SyS_open+0x1e/0x20 system_call_fastpath+0x16/0x1b ---[ end trace 11042e2848880209 ]--- Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffffa056b4fa We want to keep the WARN_ON() and stack trace so the driver can be fixed, but we can avoid the kernel panic by returning an error. We may still get warnings like this: Call Trace: pci_enable_msix+0x3c9/0x3e0 igbuio_pci_open+0x72/0x300 [igb_uio] uio_open+0xcc/0x120 [uio] chrdev_open+0xa1/0x1e0 [...] do_sys_open+0xf3/0x1f0 SyS_open+0x1e/0x20 system_call_fastpath+0x16/0x1b ------------[ cut here ]------------ WARNING: at fs/sysfs/dir.c:526 sysfs_add_one+0xa5/0xd0() sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:03.0/0000:01:00.1/msi_irqs' Signed-off-by: Tonghao Zhang [bhelgaas: changelog, fix patch whitespace, remove !!] Signed-off-by: Bjorn Helgaas

PCI/MSI: Set IRQCHIP_ONESHOT_SAFE for PCI-MSI irqchips

2018-08-14T21:11:02+00:00

If flag IRQCHIP_ONESHOT_SAFE isn't set for an irqchip and we have a threaded interrupt with no primary handler, flag IRQF_ONESHOT needs to be set for the interrupt, causing some overhead in the threaded interrupt handler. For more detailed explanation also check following comment in __setup_irq(): The interrupt was requested with handler = NULL, so we use the default primary handler for it. But it does not have the oneshot flag set. In combination with level interrupts this is deadly, because the default primary handler just wakes the thread, then the irq lines is reenabled, but the device still has the level irq asserted. Rinse and repeat.... While this works for edge type interrupts, we play it safe and reject unconditionally because we can't say for sure which type this interrupt really has. The type flags are unreliable as the underlying chip implementation can override them. Another comment in __setup_irq() gives a hint already that this overhead can be avoided for PCI-MSI: Some irq chips like MSI based interrupts are per se one shot safe. Check the chip flags, so we can avoid the unmask dance at the end of the threaded handler for those. Following this let's mark all PCI-MSI irqchips as oneshot-safe. See also discussion here: https://lkml.kernel.org/r/alpine.DEB.2.21.1808032136490.1658@nanos.tec.linutronix.de Signed-off-by: Heiner Kallweit Signed-off-by: Bjorn Helgaas

treewide: kzalloc() -> kcalloc()

2018-06-12T23:19:22+00:00

The kzalloc() function has a 2-factor argument form, kcalloc(). This patch replaces cases of: kzalloc(a * b, gfp) with: kcalloc(a * b, gfp) as well as handling cases of: kzalloc(a * b * c, gfp) with: kzalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kzalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kzalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(char) * COUNT + COUNT , ...) | kzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kzalloc + kcalloc ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kzalloc(C1 * C2 * C3, ...) | kzalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kzalloc(sizeof(THING) * C2, ...) | kzalloc(sizeof(TYPE) * C2, ...) | kzalloc(C1 * C2 * C3, ...) | kzalloc(C1 * C2, ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - (E1) * E2 + E1, E2 , ...) | - kzalloc + kcalloc ( - (E1) * (E2) + E1, E2 , ...) | - kzalloc + kcalloc ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook

genirq/msi: Limit level-triggered MSI to platform devices

2018-05-13T13:58:59+00:00

Nobody would be insane enough to try and use level triggered MSIs on PCI, but let's make sure it doesn't happen. Also, let's mandate that the irqchip backing the platform MSI domain is providing the IRQCHIP_SUPPORTS_LEVEL_MSI flag. Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Cc: Rob Herring Cc: Jason Cooper Cc: Ard Biesheuvel Cc: Srinivas Kandagatla Cc: Thomas Petazzoni Cc: Miquel Raynal Link: https://lkml.kernel.org/r/20180508121438.11301-3-marc.zyngier@arm.com