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Diffstat (limited to 'include/linux/msi.h')
-rw-r--r-- | include/linux/msi.h | 493 |
1 files changed, 493 insertions, 0 deletions
diff --git a/include/linux/msi.h b/include/linux/msi.h new file mode 100644 index 000000000..e5dfb9cf3 --- /dev/null +++ b/include/linux/msi.h @@ -0,0 +1,493 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef LINUX_MSI_H +#define LINUX_MSI_H + +/* + * This header file contains MSI data structures and functions which are + * only relevant for: + * - Interrupt core code + * - PCI/MSI core code + * - MSI interrupt domain implementations + * - IOMMU, low level VFIO, NTB and other justified exceptions + * dealing with low level MSI details. + * + * Regular device drivers have no business with any of these functions and + * especially storing MSI descriptor pointers in random code is considered + * abuse. The only function which is relevant for drivers is msi_get_virq(). + */ + +#include <linux/cpumask.h> +#include <linux/xarray.h> +#include <linux/mutex.h> +#include <linux/list.h> +#include <asm/msi.h> + +/* Dummy shadow structures if an architecture does not define them */ +#ifndef arch_msi_msg_addr_lo +typedef struct arch_msi_msg_addr_lo { + u32 address_lo; +} __attribute__ ((packed)) arch_msi_msg_addr_lo_t; +#endif + +#ifndef arch_msi_msg_addr_hi +typedef struct arch_msi_msg_addr_hi { + u32 address_hi; +} __attribute__ ((packed)) arch_msi_msg_addr_hi_t; +#endif + +#ifndef arch_msi_msg_data +typedef struct arch_msi_msg_data { + u32 data; +} __attribute__ ((packed)) arch_msi_msg_data_t; +#endif + +/** + * msi_msg - Representation of a MSI message + * @address_lo: Low 32 bits of msi message address + * @arch_addrlo: Architecture specific shadow of @address_lo + * @address_hi: High 32 bits of msi message address + * (only used when device supports it) + * @arch_addrhi: Architecture specific shadow of @address_hi + * @data: MSI message data (usually 16 bits) + * @arch_data: Architecture specific shadow of @data + */ +struct msi_msg { + union { + u32 address_lo; + arch_msi_msg_addr_lo_t arch_addr_lo; + }; + union { + u32 address_hi; + arch_msi_msg_addr_hi_t arch_addr_hi; + }; + union { + u32 data; + arch_msi_msg_data_t arch_data; + }; +}; + +extern int pci_msi_ignore_mask; +/* Helper functions */ +struct irq_data; +struct msi_desc; +struct pci_dev; +struct platform_msi_priv_data; +struct device_attribute; + +void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg); +#ifdef CONFIG_GENERIC_MSI_IRQ +void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg); +#else +static inline void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg) +{ +} +#endif + +typedef void (*irq_write_msi_msg_t)(struct msi_desc *desc, + struct msi_msg *msg); + +/** + * pci_msi_desc - PCI/MSI specific MSI descriptor data + * + * @msi_mask: [PCI MSI] MSI cached mask bits + * @msix_ctrl: [PCI MSI-X] MSI-X cached per vector control bits + * @is_msix: [PCI MSI/X] True if MSI-X + * @multiple: [PCI MSI/X] log2 num of messages allocated + * @multi_cap: [PCI MSI/X] log2 num of messages supported + * @can_mask: [PCI MSI/X] Masking supported? + * @is_64: [PCI MSI/X] Address size: 0=32bit 1=64bit + * @default_irq:[PCI MSI/X] The default pre-assigned non-MSI irq + * @mask_pos: [PCI MSI] Mask register position + * @mask_base: [PCI MSI-X] Mask register base address + */ +struct pci_msi_desc { + union { + u32 msi_mask; + u32 msix_ctrl; + }; + struct { + u8 is_msix : 1; + u8 multiple : 3; + u8 multi_cap : 3; + u8 can_mask : 1; + u8 is_64 : 1; + u8 is_virtual : 1; + unsigned default_irq; + } msi_attrib; + union { + u8 mask_pos; + void __iomem *mask_base; + }; +}; + +#define MSI_MAX_INDEX ((unsigned int)USHRT_MAX) + +/** + * struct msi_desc - Descriptor structure for MSI based interrupts + * @irq: The base interrupt number + * @nvec_used: The number of vectors used + * @dev: Pointer to the device which uses this descriptor + * @msg: The last set MSI message cached for reuse + * @affinity: Optional pointer to a cpu affinity mask for this descriptor + * @sysfs_attr: Pointer to sysfs device attribute + * + * @write_msi_msg: Callback that may be called when the MSI message + * address or data changes + * @write_msi_msg_data: Data parameter for the callback. + * + * @msi_index: Index of the msi descriptor + * @pci: PCI specific msi descriptor data + */ +struct msi_desc { + /* Shared device/bus type independent data */ + unsigned int irq; + unsigned int nvec_used; + struct device *dev; + struct msi_msg msg; + struct irq_affinity_desc *affinity; +#ifdef CONFIG_IRQ_MSI_IOMMU + const void *iommu_cookie; +#endif +#ifdef CONFIG_SYSFS + struct device_attribute *sysfs_attrs; +#endif + + void (*write_msi_msg)(struct msi_desc *entry, void *data); + void *write_msi_msg_data; + + u16 msi_index; + struct pci_msi_desc pci; +}; + +/* + * Filter values for the MSI descriptor iterators and accessor functions. + */ +enum msi_desc_filter { + /* All descriptors */ + MSI_DESC_ALL, + /* Descriptors which have no interrupt associated */ + MSI_DESC_NOTASSOCIATED, + /* Descriptors which have an interrupt associated */ + MSI_DESC_ASSOCIATED, +}; + +/** + * msi_device_data - MSI per device data + * @properties: MSI properties which are interesting to drivers + * @platform_data: Platform-MSI specific data + * @mutex: Mutex protecting the MSI descriptor store + * @__store: Xarray for storing MSI descriptor pointers + * @__iter_idx: Index to search the next entry for iterators + */ +struct msi_device_data { + unsigned long properties; + struct platform_msi_priv_data *platform_data; + struct mutex mutex; + struct xarray __store; + unsigned long __iter_idx; +}; + +int msi_setup_device_data(struct device *dev); + +unsigned int msi_get_virq(struct device *dev, unsigned int index); +void msi_lock_descs(struct device *dev); +void msi_unlock_descs(struct device *dev); + +struct msi_desc *msi_first_desc(struct device *dev, enum msi_desc_filter filter); +struct msi_desc *msi_next_desc(struct device *dev, enum msi_desc_filter filter); + +/** + * msi_for_each_desc - Iterate the MSI descriptors + * + * @desc: struct msi_desc pointer used as iterator + * @dev: struct device pointer - device to iterate + * @filter: Filter for descriptor selection + * + * Notes: + * - The loop must be protected with a msi_lock_descs()/msi_unlock_descs() + * pair. + * - It is safe to remove a retrieved MSI descriptor in the loop. + */ +#define msi_for_each_desc(desc, dev, filter) \ + for ((desc) = msi_first_desc((dev), (filter)); (desc); \ + (desc) = msi_next_desc((dev), (filter))) + +#define msi_desc_to_dev(desc) ((desc)->dev) + +#ifdef CONFIG_IRQ_MSI_IOMMU +static inline const void *msi_desc_get_iommu_cookie(struct msi_desc *desc) +{ + return desc->iommu_cookie; +} + +static inline void msi_desc_set_iommu_cookie(struct msi_desc *desc, + const void *iommu_cookie) +{ + desc->iommu_cookie = iommu_cookie; +} +#else +static inline const void *msi_desc_get_iommu_cookie(struct msi_desc *desc) +{ + return NULL; +} + +static inline void msi_desc_set_iommu_cookie(struct msi_desc *desc, + const void *iommu_cookie) +{ +} +#endif + +#ifdef CONFIG_PCI_MSI +struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc); +void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg); +#else /* CONFIG_PCI_MSI */ +static inline void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg) +{ +} +#endif /* CONFIG_PCI_MSI */ + +int msi_add_msi_desc(struct device *dev, struct msi_desc *init_desc); +void msi_free_msi_descs_range(struct device *dev, enum msi_desc_filter filter, + unsigned int first_index, unsigned int last_index); + +/** + * msi_free_msi_descs - Free MSI descriptors of a device + * @dev: Device to free the descriptors + */ +static inline void msi_free_msi_descs(struct device *dev) +{ + msi_free_msi_descs_range(dev, MSI_DESC_ALL, 0, MSI_MAX_INDEX); +} + +void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg); +void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg); + +void pci_msi_mask_irq(struct irq_data *data); +void pci_msi_unmask_irq(struct irq_data *data); + +/* + * The arch hooks to setup up msi irqs. Default functions are implemented + * as weak symbols so that they /can/ be overriden by architecture specific + * code if needed. These hooks can only be enabled by the architecture. + * + * If CONFIG_PCI_MSI_ARCH_FALLBACKS is not selected they are replaced by + * stubs with warnings. + */ +#ifdef CONFIG_PCI_MSI_ARCH_FALLBACKS +int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc); +void arch_teardown_msi_irq(unsigned int irq); +int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type); +void arch_teardown_msi_irqs(struct pci_dev *dev); +#endif /* CONFIG_PCI_MSI_ARCH_FALLBACKS */ + +/* + * Xen uses non-default msi_domain_ops and hence needs a way to populate sysfs + * entries of MSI IRQs. + */ +#if defined(CONFIG_PCI_XEN) || defined(CONFIG_PCI_MSI_ARCH_FALLBACKS) +#ifdef CONFIG_SYSFS +int msi_device_populate_sysfs(struct device *dev); +void msi_device_destroy_sysfs(struct device *dev); +#else /* CONFIG_SYSFS */ +static inline int msi_device_populate_sysfs(struct device *dev) { return 0; } +static inline void msi_device_destroy_sysfs(struct device *dev) { } +#endif /* !CONFIG_SYSFS */ +#endif /* CONFIG_PCI_XEN || CONFIG_PCI_MSI_ARCH_FALLBACKS */ + +/* + * The restore hook is still available even for fully irq domain based + * setups. Courtesy to XEN/X86. + */ +bool arch_restore_msi_irqs(struct pci_dev *dev); + +#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN + +#include <linux/irqhandler.h> + +struct irq_domain; +struct irq_domain_ops; +struct irq_chip; +struct device_node; +struct fwnode_handle; +struct msi_domain_info; + +/** + * struct msi_domain_ops - MSI interrupt domain callbacks + * @get_hwirq: Retrieve the resulting hw irq number + * @msi_init: Domain specific init function for MSI interrupts + * @msi_free: Domain specific function to free a MSI interrupts + * @msi_check: Callback for verification of the domain/info/dev data + * @msi_prepare: Prepare the allocation of the interrupts in the domain + * @set_desc: Set the msi descriptor for an interrupt + * @domain_alloc_irqs: Optional function to override the default allocation + * function. + * @domain_free_irqs: Optional function to override the default free + * function. + * + * @get_hwirq, @msi_init and @msi_free are callbacks used by the underlying + * irqdomain. + * + * @msi_check, @msi_prepare and @set_desc are callbacks used by + * msi_domain_alloc/free_irqs(). + * + * @domain_alloc_irqs, @domain_free_irqs can be used to override the + * default allocation/free functions (__msi_domain_alloc/free_irqs). This + * is initially for a wrapper around XENs seperate MSI universe which can't + * be wrapped into the regular irq domains concepts by mere mortals. This + * allows to universally use msi_domain_alloc/free_irqs without having to + * special case XEN all over the place. + * + * Contrary to other operations @domain_alloc_irqs and @domain_free_irqs + * are set to the default implementation if NULL and even when + * MSI_FLAG_USE_DEF_DOM_OPS is not set to avoid breaking existing users and + * because these callbacks are obviously mandatory. + * + * This is NOT meant to be abused, but it can be useful to build wrappers + * for specialized MSI irq domains which need extra work before and after + * calling __msi_domain_alloc_irqs()/__msi_domain_free_irqs(). + */ +struct msi_domain_ops { + irq_hw_number_t (*get_hwirq)(struct msi_domain_info *info, + msi_alloc_info_t *arg); + int (*msi_init)(struct irq_domain *domain, + struct msi_domain_info *info, + unsigned int virq, irq_hw_number_t hwirq, + msi_alloc_info_t *arg); + void (*msi_free)(struct irq_domain *domain, + struct msi_domain_info *info, + unsigned int virq); + int (*msi_check)(struct irq_domain *domain, + struct msi_domain_info *info, + struct device *dev); + int (*msi_prepare)(struct irq_domain *domain, + struct device *dev, int nvec, + msi_alloc_info_t *arg); + void (*set_desc)(msi_alloc_info_t *arg, + struct msi_desc *desc); + int (*domain_alloc_irqs)(struct irq_domain *domain, + struct device *dev, int nvec); + void (*domain_free_irqs)(struct irq_domain *domain, + struct device *dev); +}; + +/** + * struct msi_domain_info - MSI interrupt domain data + * @flags: Flags to decribe features and capabilities + * @ops: The callback data structure + * @chip: Optional: associated interrupt chip + * @chip_data: Optional: associated interrupt chip data + * @handler: Optional: associated interrupt flow handler + * @handler_data: Optional: associated interrupt flow handler data + * @handler_name: Optional: associated interrupt flow handler name + * @data: Optional: domain specific data + */ +struct msi_domain_info { + u32 flags; + struct msi_domain_ops *ops; + struct irq_chip *chip; + void *chip_data; + irq_flow_handler_t handler; + void *handler_data; + const char *handler_name; + void *data; +}; + +/* Flags for msi_domain_info */ +enum { + /* + * Init non implemented ops callbacks with default MSI domain + * callbacks. + */ + MSI_FLAG_USE_DEF_DOM_OPS = (1 << 0), + /* + * Init non implemented chip callbacks with default MSI chip + * callbacks. + */ + MSI_FLAG_USE_DEF_CHIP_OPS = (1 << 1), + /* Support multiple PCI MSI interrupts */ + MSI_FLAG_MULTI_PCI_MSI = (1 << 2), + /* Support PCI MSIX interrupts */ + MSI_FLAG_PCI_MSIX = (1 << 3), + /* Needs early activate, required for PCI */ + MSI_FLAG_ACTIVATE_EARLY = (1 << 4), + /* + * Must reactivate when irq is started even when + * MSI_FLAG_ACTIVATE_EARLY has been set. + */ + MSI_FLAG_MUST_REACTIVATE = (1 << 5), + /* Is level-triggered capable, using two messages */ + MSI_FLAG_LEVEL_CAPABLE = (1 << 6), + /* Populate sysfs on alloc() and destroy it on free() */ + MSI_FLAG_DEV_SYSFS = (1 << 7), + /* MSI-X entries must be contiguous */ + MSI_FLAG_MSIX_CONTIGUOUS = (1 << 8), + /* Allocate simple MSI descriptors */ + MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS = (1 << 9), + /* Free MSI descriptors */ + MSI_FLAG_FREE_MSI_DESCS = (1 << 10), +}; + +int msi_domain_set_affinity(struct irq_data *data, const struct cpumask *mask, + bool force); + +struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode, + struct msi_domain_info *info, + struct irq_domain *parent); +int __msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, + int nvec); +int msi_domain_alloc_irqs_descs_locked(struct irq_domain *domain, struct device *dev, + int nvec); +int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, + int nvec); +void __msi_domain_free_irqs(struct irq_domain *domain, struct device *dev); +void msi_domain_free_irqs_descs_locked(struct irq_domain *domain, struct device *dev); +void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev); +struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain); + +struct irq_domain *platform_msi_create_irq_domain(struct fwnode_handle *fwnode, + struct msi_domain_info *info, + struct irq_domain *parent); +int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec, + irq_write_msi_msg_t write_msi_msg); +void platform_msi_domain_free_irqs(struct device *dev); + +/* When an MSI domain is used as an intermediate domain */ +int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev, + int nvec, msi_alloc_info_t *args); +int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev, + int virq, int nvec, msi_alloc_info_t *args); +struct irq_domain * +__platform_msi_create_device_domain(struct device *dev, + unsigned int nvec, + bool is_tree, + irq_write_msi_msg_t write_msi_msg, + const struct irq_domain_ops *ops, + void *host_data); + +#define platform_msi_create_device_domain(dev, nvec, write, ops, data) \ + __platform_msi_create_device_domain(dev, nvec, false, write, ops, data) +#define platform_msi_create_device_tree_domain(dev, nvec, write, ops, data) \ + __platform_msi_create_device_domain(dev, nvec, true, write, ops, data) + +int platform_msi_device_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs); +void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int virq, + unsigned int nvec); +void *platform_msi_get_host_data(struct irq_domain *domain); +#endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */ + +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN +struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode, + struct msi_domain_info *info, + struct irq_domain *parent); +u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev); +struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev); +bool pci_dev_has_special_msi_domain(struct pci_dev *pdev); +#else +static inline struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev) +{ + return NULL; +} +#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */ + +#endif /* LINUX_MSI_H */ |