arch/c6x/include/asm/irq.h

   1 /*
   2  *  Port on Texas Instruments TMS320C6x architecture
   3  *
   4  *  Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
   5  *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
   6  *
   7  *  Large parts taken directly from powerpc.
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2 as
  11  *  published by the Free Software Foundation.
  12  */
  13 #ifndef _ASM_C6X_IRQ_H
  14 #define _ASM_C6X_IRQ_H
  15
  16 #include <linux/threads.h>
  17 #include <linux/list.h>
  18 #include <linux/radix-tree.h>
  19 #include <asm/percpu.h>
  20
  21 #define irq_canonicalize(irq)  (irq)
  22
  23 /*
  24  * The C64X+ core has 16 IRQ vectors. One each is used by Reset and NMI. Two
  25  * are reserved. The remaining 12 vectors are used to route SoC interrupts.
  26  * These interrupt vectors are prioritized with IRQ 4 having the highest
  27  * priority and IRQ 15 having the lowest.
  28  *
  29  * The C64x+ megamodule provides a PIC which combines SoC IRQ sources into a
  30  * single core IRQ vector. There are four combined sources, each of which
  31  * feed into one of the 12 general interrupt vectors. The remaining 8 vectors
  32  * can each route a single SoC interrupt directly.
  33  */
  34 #define NR_PRIORITY_IRQS 16
  35
  36 #define NR_IRQS_LEGACY  NR_PRIORITY_IRQS
  37
  38 /* Total number of virq in the platform */
  39 #define NR_IRQS         256
  40
  41 /* This number is used when no interrupt has been assigned */
  42 #define NO_IRQ          0
  43
  44 /* This type is the placeholder for a hardware interrupt number. It has to
  45  * be big enough to enclose whatever representation is used by a given
  46  * platform.
  47  */
  48 typedef unsigned long irq_hw_number_t;
  49
  50 /* Interrupt controller "host" data structure. This could be defined as a
  51  * irq domain controller. That is, it handles the mapping between hardware
  52  * and virtual interrupt numbers for a given interrupt domain. The host
  53  * structure is generally created by the PIC code for a given PIC instance
  54  * (though a host can cover more than one PIC if they have a flat number
  55  * model). It's the host callbacks that are responsible for setting the
  56  * irq_chip on a given irq_desc after it's been mapped.
  57  *
  58  * The host code and data structures are fairly agnostic to the fact that
  59  * we use an open firmware device-tree. We do have references to struct
  60  * device_node in two places: in irq_find_host() to find the host matching
  61  * a given interrupt controller node, and of course as an argument to its
  62  * counterpart host->ops->match() callback. However, those are treated as
  63  * generic pointers by the core and the fact that it's actually a device-node
  64  * pointer is purely a convention between callers and implementation. This
  65  * code could thus be used on other architectures by replacing those two
  66  * by some sort of arch-specific void * "token" used to identify interrupt
  67  * controllers.
  68  */
  69 struct irq_host;
  70 struct radix_tree_root;
  71 struct device_node;
  72
  73 /* Functions below are provided by the host and called whenever a new mapping
  74  * is created or an old mapping is disposed. The host can then proceed to
  75  * whatever internal data structures management is required. It also needs
  76  * to setup the irq_desc when returning from map().
  77  */
  78 struct irq_host_ops {
  79         /* Match an interrupt controller device node to a host, returns
  80          * 1 on a match
  81          */
  82         int (*match)(struct irq_host *h, struct device_node *node);
  83
  84         /* Create or update a mapping between a virtual irq number and a hw
  85          * irq number. This is called only once for a given mapping.
  86          */
  87         int (*map)(struct irq_host *h, unsigned int virq, irq_hw_number_t hw);
  88
  89         /* Dispose of such a mapping */
  90         void (*unmap)(struct irq_host *h, unsigned int virq);
  91
  92         /* Translate device-tree interrupt specifier from raw format coming
  93          * from the firmware to a irq_hw_number_t (interrupt line number) and
  94          * type (sense) that can be passed to set_irq_type(). In the absence
  95          * of this callback, irq_create_of_mapping() and irq_of_parse_and_map()
  96          * will return the hw number in the first cell and IRQ_TYPE_NONE for
  97          * the type (which amount to keeping whatever default value the
  98          * interrupt controller has for that line)
  99          */
 100         int (*xlate)(struct irq_host *h, struct device_node *ctrler,
 101                      const u32 *intspec, unsigned int intsize,
 102                      irq_hw_number_t *out_hwirq, unsigned int *out_type);
 103 };
 104
 105 struct irq_host {
 106         struct list_head        link;
 107
 108         /* type of reverse mapping technique */
 109         unsigned int            revmap_type;
 110 #define IRQ_HOST_MAP_PRIORITY   0 /* core priority irqs, get irqs 1..15 */
 111 #define IRQ_HOST_MAP_NOMAP      1 /* no fast reverse mapping */
 112 #define IRQ_HOST_MAP_LINEAR     2 /* linear map of interrupts */
 113 #define IRQ_HOST_MAP_TREE       3 /* radix tree */
 114         union {
 115                 struct {
 116                         unsigned int size;
 117                         unsigned int *revmap;
 118                 } linear;
 119                 struct radix_tree_root tree;
 120         } revmap_data;
 121         struct irq_host_ops     *ops;
 122         void                    *host_data;
 123         irq_hw_number_t         inval_irq;
 124
 125         /* Optional device node pointer */
 126         struct device_node      *of_node;
 127 };
 128
 129 struct irq_data;
 130 extern irq_hw_number_t irqd_to_hwirq(struct irq_data *d);
 131 extern irq_hw_number_t virq_to_hw(unsigned int virq);
 132 extern bool virq_is_host(unsigned int virq, struct irq_host *host);
 133
 134 /**
 135  * irq_alloc_host - Allocate a new irq_host data structure
 136  * @of_node: optional device-tree node of the interrupt controller
 137  * @revmap_type: type of reverse mapping to use
 138  * @revmap_arg: for IRQ_HOST_MAP_LINEAR linear only: size of the map
 139  * @ops: map/unmap host callbacks
 140  * @inval_irq: provide a hw number in that host space that is always invalid
 141  *
 142  * Allocates and initialize and irq_host structure. Note that in the case of
 143  * IRQ_HOST_MAP_LEGACY, the map() callback will be called before this returns
 144  * for all legacy interrupts except 0 (which is always the invalid irq for
 145  * a legacy controller). For a IRQ_HOST_MAP_LINEAR, the map is allocated by
 146  * this call as well. For a IRQ_HOST_MAP_TREE, the radix tree will be allocated
 147  * later during boot automatically (the reverse mapping will use the slow path
 148  * until that happens).
 149  */
 150 extern struct irq_host *irq_alloc_host(struct device_node *of_node,
 151                                        unsigned int revmap_type,
 152                                        unsigned int revmap_arg,
 153                                        struct irq_host_ops *ops,
 154                                        irq_hw_number_t inval_irq);
 155
 156
 157 /**
 158  * irq_find_host - Locates a host for a given device node
 159  * @node: device-tree node of the interrupt controller
 160  */
 161 extern struct irq_host *irq_find_host(struct device_node *node);
 162
 163
 164 /**
 165  * irq_set_default_host - Set a "default" host
 166  * @host: default host pointer
 167  *
 168  * For convenience, it's possible to set a "default" host that will be used
 169  * whenever NULL is passed to irq_create_mapping(). It makes life easier for
 170  * platforms that want to manipulate a few hard coded interrupt numbers that
 171  * aren't properly represented in the device-tree.
 172  */
 173 extern void irq_set_default_host(struct irq_host *host);
 174
 175
 176 /**
 177  * irq_set_virq_count - Set the maximum number of virt irqs
 178  * @count: number of linux virtual irqs, capped with NR_IRQS
 179  *
 180  * This is mainly for use by platforms like iSeries who want to program
 181  * the virtual irq number in the controller to avoid the reverse mapping
 182  */
 183 extern void irq_set_virq_count(unsigned int count);
 184
 185
 186 /**
 187  * irq_create_mapping - Map a hardware interrupt into linux virq space
 188  * @host: host owning this hardware interrupt or NULL for default host
 189  * @hwirq: hardware irq number in that host space
 190  *
 191  * Only one mapping per hardware interrupt is permitted. Returns a linux
 192  * virq number.
 193  * If the sense/trigger is to be specified, set_irq_type() should be called
 194  * on the number returned from that call.
 195  */
 196 extern unsigned int irq_create_mapping(struct irq_host *host,
 197                                        irq_hw_number_t hwirq);
 198
 199
 200 /**
 201  * irq_dispose_mapping - Unmap an interrupt
 202  * @virq: linux virq number of the interrupt to unmap
 203  */
 204 extern void irq_dispose_mapping(unsigned int virq);
 205
 206 /**
 207  * irq_find_mapping - Find a linux virq from an hw irq number.
 208  * @host: host owning this hardware interrupt
 209  * @hwirq: hardware irq number in that host space
 210  *
 211  * This is a slow path, for use by generic code. It's expected that an
 212  * irq controller implementation directly calls the appropriate low level
 213  * mapping function.
 214  */
 215 extern unsigned int irq_find_mapping(struct irq_host *host,
 216                                      irq_hw_number_t hwirq);
 217
 218 /**
 219  * irq_create_direct_mapping - Allocate a virq for direct mapping
 220  * @host: host to allocate the virq for or NULL for default host
 221  *
 222  * This routine is used for irq controllers which can choose the hardware
 223  * interrupt numbers they generate. In such a case it's simplest to use
 224  * the linux virq as the hardware interrupt number.
 225  */
 226 extern unsigned int irq_create_direct_mapping(struct irq_host *host);
 227
 228 /**
 229  * irq_radix_revmap_insert - Insert a hw irq to linux virq number mapping.
 230  * @host: host owning this hardware interrupt
 231  * @virq: linux irq number
 232  * @hwirq: hardware irq number in that host space
 233  *
 234  * This is for use by irq controllers that use a radix tree reverse
 235  * mapping for fast lookup.
 236  */
 237 extern void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 238                                     irq_hw_number_t hwirq);
 239
 240 /**
 241  * irq_radix_revmap_lookup - Find a linux virq from a hw irq number.
 242  * @host: host owning this hardware interrupt
 243  * @hwirq: hardware irq number in that host space
 244  *
 245  * This is a fast path, for use by irq controller code that uses radix tree
 246  * revmaps
 247  */
 248 extern unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 249                                             irq_hw_number_t hwirq);
 250
 251 /**
 252  * irq_linear_revmap - Find a linux virq from a hw irq number.
 253  * @host: host owning this hardware interrupt
 254  * @hwirq: hardware irq number in that host space
 255  *
 256  * This is a fast path, for use by irq controller code that uses linear
 257  * revmaps. It does fallback to the slow path if the revmap doesn't exist
 258  * yet and will create the revmap entry with appropriate locking
 259  */
 260
 261 extern unsigned int irq_linear_revmap(struct irq_host *host,
 262                                       irq_hw_number_t hwirq);
 263
 264
 265
 266 /**
 267  * irq_alloc_virt - Allocate virtual irq numbers
 268  * @host: host owning these new virtual irqs
 269  * @count: number of consecutive numbers to allocate
 270  * @hint: pass a hint number, the allocator will try to use a 1:1 mapping
 271  *
 272  * This is a low level function that is used internally by irq_create_mapping()
 273  * and that can be used by some irq controllers implementations for things
 274  * like allocating ranges of numbers for MSIs. The revmaps are left untouched.
 275  */
 276 extern unsigned int irq_alloc_virt(struct irq_host *host,
 277                                    unsigned int count,
 278                                    unsigned int hint);
 279
 280 /**
 281  * irq_free_virt - Free virtual irq numbers
 282  * @virq: virtual irq number of the first interrupt to free
 283  * @count: number of interrupts to free
 284  *
 285  * This function is the opposite of irq_alloc_virt. It will not clear reverse
 286  * maps, this should be done previously by unmap'ing the interrupt. In fact,
 287  * all interrupts covered by the range being freed should have been unmapped
 288  * prior to calling this.
 289  */
 290 extern void irq_free_virt(unsigned int virq, unsigned int count);
 291
 292 extern void __init init_pic_c64xplus(void);
 293
 294 extern void init_IRQ(void);
 295
 296 struct pt_regs;
 297
 298 extern asmlinkage void c6x_do_IRQ(unsigned int prio, struct pt_regs *regs);
 299
 300 extern unsigned long irq_err_count;
 301
 302 #endif /* _ASM_C6X_IRQ_H */