user/sven/linux.git/include/linux/msi.h, branch v6.2.7

genirq/msi, platform-msi: Ensure that MSI descriptors are unreferenced

2023-03-10T08:29:48Z

commit 0fb7fb713461e44b12e72c292bf90ee300f40710 upstream. Miquel reported a warning in the MSI core which is triggered when interrupts are freed via platform_msi_device_domain_free(). This code got reworked to use core functions for freeing the MSI descriptors, but nothing took care to clear the msi_desc->irq entry, which then triggers the warning in msi_free_msi_desc() which uses desc->irq to validate that the descriptor has been torn down. The same issue exists in msi_domain_populate_irqs(). Up to the point that msi_free_msi_descs() grew a warning for this case, this went un-noticed. Provide the counterpart of msi_domain_populate_irqs() and invoke it in platform_msi_device_domain_free() before freeing the interrupts and MSI descriptors and also in the error path of msi_domain_populate_irqs(). Fixes: 2f2940d16823 ("genirq/msi: Remove filter from msi_free_descs_free_range()") Reported-by: Miquel Raynal Signed-off-by: Thomas Gleixner Tested-by: Miquel Raynal Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87mt4wkwnv.ffs@tglx Signed-off-by: Greg Kroah-Hartman

genirq/msi: Provide constants for PCI/IMS support

2022-12-05T21:22:34Z

Provide the necessary constants for PCI/IMS support: - A new bus token for MSI irqdomain identification - A MSI feature flag for the MSI irqdomains to signal support - A secondary domain id The latter expands the device internal domain pointer storage array from 1 to 2 entries. That extra pointer is mostly unused today, but the alternative solutions would not be free either and would introduce more complexity all over the place. Trade the 8bytes for simplicity. Signed-off-by: Thomas Gleixner Reviewed-by: Kevin Tian Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20221124232326.846169830@linutronix.de

genirq/msi: Provide MSI_FLAG_MSIX_ALLOC_DYN

2022-12-05T21:22:34Z

Provide a new MSI feature flag in preparation for dynamic MSIX allocation after the initial MSI-X enable has been done. This needs to be an explicit MSI interrupt domain feature because quite some implementations (both interrupt domains and legacy allocation mode) have clear expectations that the allocation code is only invoked when MSI-X is about to be enabled. They either talk to hypervisors or do some other work and are not prepared to be invoked on an already MSI-X enabled device. This is also explicit MSI-X only because rewriting the size of the MSI entries is only possible when disabling MSI which in turn might cause lost interrupts on the device. Signed-off-by: Thomas Gleixner Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20221124232326.558843119@linutronix.de

genirq/msi: Provide msi_domain_alloc_irq_at()

2022-12-05T21:22:34Z

For supporting post MSI-X enable allocations and for the upcoming PCI/IMS support a separate interface is required which allows not only the allocation of a specific index, but also the allocation of any, i.e. the next free index. The latter is especially required for IMS because IMS completely does away with index to functionality mappings which are often found in MSI/MSI-X implementation. But even with MSI-X there are devices where only the first few indices have a fixed functionality and the rest is freely assignable by software, e.g. to queues. msi_domain_alloc_irq_at() is also different from the range based interfaces as it always enforces that the MSI descriptor is allocated by the core code and not preallocated by the caller like the PCI/MSI[-X] enable code path does. msi_domain_alloc_irq_at() can be invoked with the index argument set to MSI_ANY_INDEX which makes the core code pick the next free index. The irq domain can provide a prepare_desc() operation callback in it's msi_domain_ops to do domain specific post allocation initialization before the actual Linux interrupt and the associated interrupt descriptor and hierarchy alloccations are conducted. The function also takes an optional @icookie argument which is of type union msi_instance_cookie. This cookie is not used by the core code and is stored in the allocated msi_desc::data::icookie. The meaning of the cookie is completely implementation defined. In case of IMS this might be a PASID or a pointer to a device queue, but for the MSI core it's opaque and not used in any way. The function returns a struct msi_map which on success contains the allocated index number and the Linux interrupt number so the caller can spare the index to Linux interrupt number lookup. On failure map::index contains the error code and map::virq is 0. Signed-off-by: Thomas Gleixner Reviewed-by: Kevin Tian Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20221124232326.501359457@linutronix.de

genirq/msi: Provide msi_domain_ops:: Prepare_desc()

2022-12-05T21:22:33Z

The existing MSI domain ops msi_prepare() and set_desc() turned out to be unsuitable for implementing IMS support. msi_prepare() does not operate on the MSI descriptors. set_desc() lacks an irq_domain pointer and has a completely different purpose. Introduce a prepare_desc() op which allows IMS implementations to amend an MSI descriptor which was allocated by the core code, e.g. by adjusting the iomem base or adding some data based on the allocated index. This is way better than requiring that all IMS domain implementations preallocate the MSI descriptor and then allocate the interrupt. Signed-off-by: Thomas Gleixner Reviewed-by: Kevin Tian Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20221124232326.444560717@linutronix.de

genirq/msi: Provide msi_desc:: Msi_data

2022-12-05T21:22:33Z

The upcoming support for PCI/IMS requires to store some information related to the message handling in the MSI descriptor, e.g. PASID or a pointer to a queue. Provide a generic storage struct which maps over the existing PCI specific storage which means the size of struct msi_desc is not getting bigger. This storage struct has two elements: 1) msi_domain_cookie 2) msi_instance_cookie The domain cookie is going to be used to store domain specific information, e.g. iobase pointer, data pointer. The instance cookie is going to be handed in when allocating an interrupt on an IMS domain so the irq chip callbacks of the IMS domain have the necessary per vector information available. It also comes in handy when cleaning up the platform MSI code for wire to MSI bridges which need to hand down the type information to the underlying interrupt domain. For the core code the cookies are opaque and meaningless. It just stores the instance cookie during an allocation through the upcoming interfaces for IMS and wire to MSI brigdes. Signed-off-by: Thomas Gleixner Reviewed-by: Kevin Tian Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20221124232326.385036043@linutronix.de

PCI/MSI: Remove unused pci_dev_has_special_msi_domain()

2022-12-05T21:22:33Z

The check for special MSI domains like VMD which prevents the interrupt remapping code to overwrite device::msi::domain is not longer required and has been replaced by an x86 specific version which is aware of MSI parent domains. Remove it. Signed-off-by: Thomas Gleixner Reviewed-by: Kevin Tian Acked-by: Bjorn Helgaas Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20221124232326.093093200@linutronix.de

genirq/msi: Provide msi_match_device_domain()

2022-12-05T18:21:01Z

Provide an interface to match a per device domain bus token. This allows to query which type of domain is installed for a particular domain id. Will be used for PCI to avoid frequent create/remove cycles for the MSI resp. MSI-X domains. Signed-off-by: Thomas Gleixner Reviewed-by: Kevin Tian Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20221124232325.738047902@linutronix.de

genirq/msi: Provide msi_create/free_device_irq_domain()

2022-12-05T18:21:01Z

Now that all prerequsites are in place, provide the actual interfaces for creating and removing per device interrupt domains. MSI device interrupt domains are created from the provided msi_domain_template which is duplicated so that it can be modified for the particular device. The name of the domain and the name of the interrupt chip are composed by "$(PREFIX)$(CHIPNAME)-$(DEVNAME)" $PREFIX: The optional prefix provided by the underlying MSI parent domain via msi_parent_ops::prefix. $CHIPNAME: The name of the irq_chip in the template $DEVNAME: The name of the device The domain is further initialized through a MSI parent domain callback which fills in the required functionality for the parent domain or domains further down the hierarchy. This initialization can fail, e.g. when the requested feature or MSI domain type cannot be supported. The domain pointer is stored in the pointer array inside of msi_device_data which is attached to the domain. The domain can be removed via the API or left for disposal via devres when the device is torn down. The API removal is useful e.g. for PCI to have seperate domains for MSI and MSI-X, which are mutually exclusive and always occupy the default domain id slot. Signed-off-by: Thomas Gleixner Reviewed-by: Kevin Tian Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20221124232325.678838546@linutronix.de

genirq/msi: Add size info to struct msi_domain_info

2022-12-05T18:21:01Z

To allow proper range checking especially for dynamic allocations add a size field to struct msi_domain_info. If the field is 0 then the size is unknown or unlimited (up to MSI_MAX_INDEX) to provide backwards compability. Signed-off-by: Thomas Gleixner Reviewed-by: Kevin Tian Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20221124232325.501144862@linutronix.de