- 05 Dec, 2022 40 commits
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Thomas Gleixner authored
IMS (Interrupt Message Store) is a new specification which allows implementation specific storage of MSI messages contrary to the strict standard specified MSI and MSI-X message stores. This requires new device specific interrupt domains to handle the implementation defined storage which can be an array in device memory or host/guest memory which is shared with hardware queues. Add a function to create IMS domains for PCI devices. IMS domains are using the new per device domain mechanism and are configured by the device driver via a template. IMS domains are created as secondary device domains so they work side on side with MSI[-X] on the same device. The IMS domains have a few constraints: - The index space is managed by the core code. Device memory based IMS provides a storage array with a fixed size which obviously requires an index. But there is no association between index and functionality so the core can randomly allocate an index in the array. System memory based IMS does not have the concept of an index as the storage is somewhere in memory. In that case the index is purely software based to keep track of the allocations. - There is no requirement for consecutive index ranges This is currently a limitation of the MSI core and can be implemented if there is a justified use case by changing the internal storage from xarray to maple_tree. For now it's single vector allocation. - The interrupt chip must provide the following callbacks: - irq_mask() - irq_unmask() - irq_write_msi_msg() - The interrupt chip must provide the following optional callbacks when the irq_mask(), irq_unmask() and irq_write_msi_msg() callbacks cannot operate directly on hardware, e.g. in the case that the interrupt message store is in queue memory: - irq_bus_lock() - irq_bus_unlock() These callbacks are invoked from preemptible task context and are allowed to sleep. In this case the mandatory callbacks above just store the information. The irq_bus_unlock() callback is supposed to make the change effective before returning. - Interrupt affinity setting is handled by the underlying parent interrupt domain and communicated to the IMS domain via irq_write_msi_msg(). IMS domains cannot have a irq_set_affinity() callback. That's a reasonable restriction similar to the PCI/MSI device domain implementations. The domain is automatically destroyed when the PCI device is removed. Signed-off-by:Thomas Gleixner <tglx@linutronix.de> Reviewed-by:
Kevin Tian <kevin.tian@intel.com> Acked-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221124232326.904316841@linutronix.de
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
x86 MSI irqdomains can handle MSI-X allocation post MSI-X enable just out of the box - on the vector domain and on the remapping domains, Add the feature flag to the supported feature list Signed-off-by:
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Thomas Gleixner authored
MSI-X vectors can be allocated after the initial MSI-X enablement, but this needs explicit support of the underlying interrupt domains. Provide a function to query the ability and functions to allocate/free individual vectors post-enable. The allocation can either request a specific index in the MSI-X table or with the index argument MSI_ANY_INDEX it allocates the next free vector. The return value is a struct msi_map which on success contains both index and the Linux interrupt number. In case of failure index is negative and the Linux interrupt number is 0. The allocation function is for a single MSI-X index at a time as that's sufficient for the most urgent use case VFIO to get rid of the 'disable MSI-X, reallocate, enable-MSI-X' cycle which is prone to lost interrupts and redirections to the legacy and obviously unhandled INTx. As single index allocation is also sufficient for the use cases Jason Gunthorpe pointed out: Allocation of a MSI-X or IMS vector for a network queue. See Link below. Signed-off-by:
Bjorn Helgaas <bhelgaas@google.com> Acked-by:
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Thomas Gleixner authored
The setup of MSI descriptors for PCI/MSI-X interrupts depends partially on the MSI index for which the descriptor is initialized. Dynamic MSI-X vector allocation post MSI-X enablement allows to allocate vectors at a given index or at any free index in the available table range. The latter requires that the descriptor is initialized after the MSI core has chosen an index. Implement the prepare_desc() op in the PCI/MSI-X specific msi_domain_ops which is invoked before the core interrupt descriptor and the associated Linux interrupt number is allocated. That callback is also provided for the upcoming PCI/IMS implementations so the implementation specific interrupt domain can do their domain specific initialization of the MSI descriptors. Signed-off-by:
Jason Gunthorpe <jgg@nvidia.com> Reviewed-by:
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Thomas Gleixner authored
The upcoming mechanism to allocate MSI-X vectors after enabling MSI-X needs to share some of the MSI-X descriptor setup. The regular descriptor setup on enable has the following code flow: 1) Allocate descriptor 2) Setup descriptor with PCI specific data 3) Insert descriptor 4) Allocate interrupts which in turn scans the inserted descriptors This cannot be easily changed because the PCI/MSI code needs to handle the legacy architecture specific allocation model and the irq domain model where quite some domains have the assumption that the above flow is how it works. Ideally the code flow should look like this: 1) Invoke allocation at the MSI core 2) MSI core allocates descriptor 3) MSI core calls back into the irq domain which fills in the domain specific parts This could be done for underlying parent MSI domains which support post-enable allocation/free but that would create significantly different code pathes for MSI/MSI-X enable. Though for dynamic allocation which wants to share the allocation code with the upcoming PCI/IMS support it's the right thing to do. Split the MSI-X descriptor setup into the preallocation part which just sets the index and fills in the horrible hack of virtual IRQs and the real PCI specific MSI-X setup part which solely depends on the index in the descriptor. This allows to provide a common dynamic allocation interface at the MSI core level for both PCI/MSI-X and PCI/IMS. Signed-off-by: -
Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
A simple struct to hold a MSI index / Linux interrupt number pair. It will be returned from the dynamic vector allocation function and handed back to the corresponding free() function. Signed-off-by:
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Thomas Gleixner authored
and related code which is not longer required now that the interrupt remap code has been converted to MSI parent domains. Signed-off-by:
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Thomas Gleixner authored
Remove the global PCI/MSI irqdomain implementation and provide the required MSI parent ops so the PCI/MSI code can detect the new parent and setup per device domains. Signed-off-by:
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Thomas Gleixner authored
Remove the global PCI/MSI irqdomain implementation and provide the required MSI parent ops so the PCI/MSI code can detect the new parent and setup per device domains. Signed-off-by:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
Enable MSI parent domain support in the x86 vector domain and fixup the checks in the iommu implementations to check whether device::msi::domain is the default MSI parent domain. That keeps the existing logic to protect e.g. devices behind VMD working. The interrupt remap PCI/MSI code still works because the underlying vector domain still provides the same functionality. None of the other x86 PCI/MSI, e.g. XEN and HyperV, implementations are affected either. They still work the same way both at the low level and the PCI/MSI implementations they provide. Signed-off-by:
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Thomas Gleixner authored
Provide a template and the necessary callbacks to create PCI/MSI and PCI/MSI-X domains. The domains are created when MSI or MSI-X is enabled. The domain's lifetime is either the device lifetime or in case that e.g. MSI-X was tried first and failed, then the MSI-X domain is removed and a MSI domain is created as both are mutually exclusive and reside in the default domain ID slot of the per device domain pointer array. Also expand pci_msi_domain_supports() to handle feature checks correctly even in the case that the per device domain was not yet created by checking the features supported by the MSI parent. Add the necessary setup calls into the MSI and MSI-X enable code path. These setup calls are backwards compatible. They return success when there is no parent domain found, which means the existing global domains or the legacy allocation path keep just working. Co-developed-by:
Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by:
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Thomas Gleixner authored
Provide new bus tokens for the upcoming per device PCI/MSI and PCI/MSIX interrupt domains. Signed-off-by:
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Thomas Gleixner authored
The upcoming per device MSI domains will create different domains for MSI and MSI-X. Split the write message function into MSI and MSI-X helpers so they can be used by those new domain functions seperately. Signed-off-by:
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Thomas Gleixner authored
Per device domains provide the real domain size to the core code. This allows range checking on insertion of MSI descriptors and also paves the way for dynamic index allocations which are required e.g. for IMS. This avoids external mechanisms like bitmaps on the device side and just utilizes the core internal MSI descriptor storxe for it. Signed-off-by:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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 authored
Per device domains require the device pointer of the device which instantiated the domain for some purposes. Add the pointer to struct irq_domain. It will be used in the next step which provides the infrastructure to create per device MSI domains. Signed-off-by:
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Thomas Gleixner authored
Split the functionality of msi_create_irq_domain() so it can be reused for creating per device irq domains. No functional change. Signed-off-by:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
Provide struct msi_domain_template which contains a bundle of struct irq_chip, struct msi_domain_ops and struct msi_domain_info and a name field. This template is used by MSI device domain implementations to provide the domain specific functionality, feature bits etc. When a MSI domain is created the template is duplicated in the core code so that it can be modified per instance. That means templates can be marked const at the MSI device domain code. The template is a bundle to avoid several allocations and duplications of the involved structures. The name field is used to construct the final domain and chip name via: $PREFIX$NAME-$DEVNAME where prefix is the optional prefix of the MSI parent domain, $NAME is the provided name in template::chip and the device name so that the domain is properly identified. On x86 this results for PCI/MSI in: PCI-MSI-0000:3d:00.1 or IR-PCI-MSIX-0000:3d:00.1 depending on the domain type and the availability of remapping. Signed-off-by: -
Thomas Gleixner authored
MSI parent domains must have some control over the MSI domains which are built on top. On domain creation they need to fill in e.g. architecture specific chip callbacks or msi domain ops to make the outermost domain parent agnostic which is obviously required for architecture independence etc. The structure contains: 1) A bitfield which exposes the supported functional features. This allows to check for features and is also used in the initialization callback to mask out unsupported features when the actual domain implementation requests a broader range, e.g. on x86 PCI multi-MSI is only supported by remapping domains but not by the underlying vector domain. The PCI/MSI code can then always request multi-MSI support, but the resulting feature set after creation might not have it set. 2) An optional string prefix which is put in front of domain and chip names during creation of the MSI domain. That allows to keep the naming schemes e.g. on x86 where PCI-MSI domains have a IR- prefix when interrupt remapping is enabled. 3) An initialization callback to sanity check the domain info of the to be created MSI domain, to restrict features and to apply changes in MSI ops and interrupt chip callbacks to accomodate to the particular MSI parent implementation and/or the underlying hierarchy. Add a conveniance function to delegate the initialization from the MSI parent domain to an underlying domain in the hierarchy. Signed-off-by: -
Thomas Gleixner authored
These flags got added as necessary and have no obvious structure. For feature support checks and masking it's convenient to have two blocks of flags: 1) Flags to control the internal behaviour like allocating/freeing MSI descriptors. Those flags do not need any support from the underlying MSI parent domain. They are mostly under the control of the outermost domain which implements the actual MSI support. 2) Flags to expose features, e.g. PCI multi-MSI or requirements which can depend on a underlying domain. No functional change. Signed-off-by: -
Thomas Gleixner authored
Now that all users are converted remove the old interfaces. Signed-off-by:
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Ahmed S. Darwish authored
Switch to the new domain id aware interfaces to phase out the previous ones. Remove the domain check as it happens in the core code now. No functional change. Signed-off-by:
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Thomas Gleixner authored
Switch to the new domain id aware interfaces to phase out the previous ones. Get rid of the MSI descriptor and domain checks as the core code detects these issues anyway. No functional change. Signed-off-by:
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Ahmed S. Darwish authored
Switch to the new domain id aware interfaces to phase out the previous ones. No functional change. Signed-off-by:
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Thomas Gleixner authored
Switch to the new domain id aware interfaces to phase out the previous ones. No functional change. Signed-off-by:
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Thomas Gleixner authored
Provide two sorts of interfaces to handle the different use cases: - msi_domain_alloc_irqs_range(): Handles a caller defined precise range - msi_domain_alloc_irqs_all(): Allocates all interrupts associated to a domain by scanning the allocated MSI descriptors The latter is useful for the existing PCI/MSI support which does not have range information available. Signed-off-by: -
Thomas Gleixner authored
Provide two sorts of interfaces to handle the different use cases: - msi_domain_free_irqs_range(): Handles a caller defined precise range - msi_domain_free_irqs_all(): Frees all interrupts associated to a domain The latter is useful for device teardown and to handle the legacy MSI support which does not have any range information available. Signed-off-by:
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Thomas Gleixner authored
Allocating simple interrupt descriptors in the core code has to be multi device irqdomain aware for the upcoming PCI/IMS support. Change the interfaces to take a domain id into account. Use the internal control struct for transport of arguments. Signed-off-by:
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Thomas Gleixner authored
Change the descriptor free functions to take a domain id to prepare for the upcoming multi MSI domain per device support. To avoid changing and extending the interfaces over and over use an core internal control struct and hand the pointer through the various functions. Signed-off-by:
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Thomas Gleixner authored
Change the descriptor allocation and insertion functions to take a domain id to prepare for the upcoming multi MSI domain per device support. Signed-off-by:
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Thomas Gleixner authored
This reflects the functionality better. No functional change. Signed-off-by:
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Ahmed S. Darwish authored
In preparation of the upcoming per device multi MSI domain support, change the interface to support lookups based on domain id and zero based index within the domain. Signed-off-by:
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