include/linux/irqdomain.h

   1 /*
   2  * irq_domain - IRQ translation domains
   3  *
   4  * Translation infrastructure between hw and linux irq numbers.  This is
   5  * helpful for interrupt controllers to implement mapping between hardware
   6  * irq numbers and the Linux irq number space.
   7  *
   8  * irq_domains also have a hook for translating device tree interrupt
   9  * representation into a hardware irq number that can be mapped back to a
  10  * Linux irq number without any extra platform support code.
  11  *
  12  * Interrupt controller "domain" data structure. This could be defined as a
  13  * irq domain controller. That is, it handles the mapping between hardware
  14  * and virtual interrupt numbers for a given interrupt domain. The domain
  15  * structure is generally created by the PIC code for a given PIC instance
  16  * (though a domain can cover more than one PIC if they have a flat number
  17  * model). It's the domain callbacks that are responsible for setting the
  18  * irq_chip on a given irq_desc after it's been mapped.
  19  *
  20  * The host code and data structures are agnostic to whether or not
  21  * we use an open firmware device-tree. We do have references to struct
  22  * device_node in two places: in irq_find_host() to find the host matching
  23  * a given interrupt controller node, and of course as an argument to its
  24  * counterpart domain->ops->match() callback. However, those are treated as
  25  * generic pointers by the core and the fact that it's actually a device-node
  26  * pointer is purely a convention between callers and implementation. This
  27  * code could thus be used on other architectures by replacing those two
  28  * by some sort of arch-specific void * "token" used to identify interrupt
  29  * controllers.
  30  */
  31
  32 #ifndef _LINUX_IRQDOMAIN_H
  33 #define _LINUX_IRQDOMAIN_H
  34
  35 #include <linux/types.h>
  36 #include <linux/radix-tree.h>
  37
  38 struct device_node;
  39 struct irq_domain;
  40 struct of_device_id;
  41
  42 /* Number of irqs reserved for a legacy isa controller */
  43 #define NUM_ISA_INTERRUPTS      16
  44
  45 /**
  46  * struct irq_domain_ops - Methods for irq_domain objects
  47  * @match: Match an interrupt controller device node to a host, returns
  48  *         1 on a match
  49  * @map: Create or update a mapping between a virtual irq number and a hw
  50  *       irq number. This is called only once for a given mapping.
  51  * @unmap: Dispose of such a mapping
  52  * @xlate: Given a device tree node and interrupt specifier, decode
  53  *         the hardware irq number and linux irq type value.
  54  *
  55  * Functions below are provided by the driver and called whenever a new mapping
  56  * is created or an old mapping is disposed. The driver can then proceed to
  57  * whatever internal data structures management is required. It also needs
  58  * to setup the irq_desc when returning from map().
  59  */
  60 struct irq_domain_ops {
  61         int (*match)(struct irq_domain *d, struct device_node *node);
  62         int (*map)(struct irq_domain *d, unsigned int virq, irq_hw_number_t hw);
  63         void (*unmap)(struct irq_domain *d, unsigned int virq);
  64         int (*xlate)(struct irq_domain *d, struct device_node *node,
  65                      const u32 *intspec, unsigned int intsize,
  66                      unsigned long *out_hwirq, unsigned int *out_type);
  67 };
  68
  69 extern struct irq_domain_ops irq_generic_chip_ops;
  70
  71 struct irq_domain_chip_generic;
  72
  73 /**
  74  * struct irq_domain - Hardware interrupt number translation object
  75  * @link: Element in global irq_domain list.
  76  * @name: Name of interrupt domain
  77  * @ops: pointer to irq_domain methods
  78  * @host_data: private data pointer for use by owner.  Not touched by irq_domain
  79  *             core code.
  80  *
  81  * Optional elements
  82  * @of_node: Pointer to device tree nodes associated with the irq_domain. Used
  83  *           when decoding device tree interrupt specifiers.
  84  * @gc: Pointer to a list of generic chips. There is a helper function for
  85  *      setting up one or more generic chips for interrupt controllers
  86  *      drivers using the generic chip library which uses this pointer.
  87  *
  88  * Revmap data, used internally by irq_domain
  89  * @revmap_direct_max_irq: The largest hwirq that can be set for controllers that
  90  *                         support direct mapping
  91  * @revmap_size: Size of the linear map table @linear_revmap[]
  92  * @revmap_tree: Radix map tree for hwirqs that don't fit in the linear map
  93  * @linear_revmap: Linear table of hwirq->virq reverse mappings
  94  */
  95 struct irq_domain {
  96         struct list_head link;
  97         const char *name;
  98         const struct irq_domain_ops *ops;
  99         void *host_data;
 100
 101         /* Optional data */
 102         struct device_node *of_node;
 103         struct irq_domain_chip_generic *gc;
 104
 105         /* reverse map data. The linear map gets appended to the irq_domain */
 106         irq_hw_number_t hwirq_max;
 107         unsigned int revmap_direct_max_irq;
 108         unsigned int revmap_size;
 109         struct radix_tree_root revmap_tree;
 110         unsigned int linear_revmap[];
 111 };
 112
 113 #ifdef CONFIG_IRQ_DOMAIN
 114 struct irq_domain *__irq_domain_add(struct device_node *of_node, int size,
 115                                     irq_hw_number_t hwirq_max, int direct_max,
 116                                     const struct irq_domain_ops *ops,
 117                                     void *host_data);
 118 struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
 119                                          unsigned int size,
 120                                          unsigned int first_irq,
 121                                          const struct irq_domain_ops *ops,
 122                                          void *host_data);
 123 struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
 124                                          unsigned int size,
 125                                          unsigned int first_irq,
 126                                          irq_hw_number_t first_hwirq,
 127                                          const struct irq_domain_ops *ops,
 128                                          void *host_data);
 129 extern struct irq_domain *irq_find_host(struct device_node *node);
 130 extern void irq_set_default_host(struct irq_domain *host);
 131
 132 /**
 133  * irq_domain_add_linear() - Allocate and register a linear revmap irq_domain.
 134  * @of_node: pointer to interrupt controller's device tree node.
 135  * @size: Number of interrupts in the domain.
 136  * @ops: map/unmap domain callbacks
 137  * @host_data: Controller private data pointer
 138  */
 139 static inline struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
 140                                          unsigned int size,
 141                                          const struct irq_domain_ops *ops,
 142                                          void *host_data)
 143 {
 144         return __irq_domain_add(of_node, size, size, 0, ops, host_data);
 145 }
 146 static inline struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
 147                                          unsigned int max_irq,
 148                                          const struct irq_domain_ops *ops,
 149                                          void *host_data)
 150 {
 151         return __irq_domain_add(of_node, 0, max_irq, max_irq, ops, host_data);
 152 }
 153 static inline struct irq_domain *irq_domain_add_legacy_isa(
 154                                 struct device_node *of_node,
 155                                 const struct irq_domain_ops *ops,
 156                                 void *host_data)
 157 {
 158         return irq_domain_add_legacy(of_node, NUM_ISA_INTERRUPTS, 0, 0, ops,
 159                                      host_data);
 160 }
 161 static inline struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
 162                                          const struct irq_domain_ops *ops,
 163                                          void *host_data)
 164 {
 165         return __irq_domain_add(of_node, 0, ~0, 0, ops, host_data);
 166 }
 167
 168 extern void irq_domain_remove(struct irq_domain *host);
 169
 170 extern int irq_domain_associate(struct irq_domain *domain, unsigned int irq,
 171                                         irq_hw_number_t hwirq);
 172 extern void irq_domain_associate_many(struct irq_domain *domain,
 173                                       unsigned int irq_base,
 174                                       irq_hw_number_t hwirq_base, int count);
 175
 176 extern unsigned int irq_create_mapping(struct irq_domain *host,
 177                                        irq_hw_number_t hwirq);
 178 extern void irq_dispose_mapping(unsigned int virq);
 179
 180 /**
 181  * irq_linear_revmap() - Find a linux irq from a hw irq number.
 182  * @domain: domain owning this hardware interrupt
 183  * @hwirq: hardware irq number in that domain space
 184  *
 185  * This is a fast path alternative to irq_find_mapping() that can be
 186  * called directly by irq controller code to save a handful of
 187  * instructions. It is always safe to call, but won't find irqs mapped
 188  * using the radix tree.
 189  */
 190 static inline unsigned int irq_linear_revmap(struct irq_domain *domain,
 191                                              irq_hw_number_t hwirq)
 192 {
 193         return hwirq < domain->revmap_size ? domain->linear_revmap[hwirq] : 0;
 194 }
 195 extern unsigned int irq_find_mapping(struct irq_domain *host,
 196                                      irq_hw_number_t hwirq);
 197 extern unsigned int irq_create_direct_mapping(struct irq_domain *host);
 198 extern int irq_create_strict_mappings(struct irq_domain *domain,
 199                                       unsigned int irq_base,
 200                                       irq_hw_number_t hwirq_base, int count);
 201
 202 static inline int irq_create_identity_mapping(struct irq_domain *host,
 203                                               irq_hw_number_t hwirq)
 204 {
 205         return irq_create_strict_mappings(host, hwirq, hwirq, 1);
 206 }
 207
 208 extern const struct irq_domain_ops irq_domain_simple_ops;
 209
 210 /* stock xlate functions */
 211 int irq_domain_xlate_onecell(struct irq_domain *d, struct device_node *ctrlr,
 212                         const u32 *intspec, unsigned int intsize,
 213                         irq_hw_number_t *out_hwirq, unsigned int *out_type);
 214 int irq_domain_xlate_twocell(struct irq_domain *d, struct device_node *ctrlr,
 215                         const u32 *intspec, unsigned int intsize,
 216                         irq_hw_number_t *out_hwirq, unsigned int *out_type);
 217 int irq_domain_xlate_onetwocell(struct irq_domain *d, struct device_node *ctrlr,
 218                         const u32 *intspec, unsigned int intsize,
 219                         irq_hw_number_t *out_hwirq, unsigned int *out_type);
 220
 221 #else /* CONFIG_IRQ_DOMAIN */
 222 static inline void irq_dispose_mapping(unsigned int virq) { }
 223 #endif /* !CONFIG_IRQ_DOMAIN */
 224
 225 #endif /* _LINUX_IRQDOMAIN_H */