linux/arch/powerpc/include/asm/irq.h
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   1#ifdef __KERNEL__
   2#ifndef _ASM_POWERPC_IRQ_H
   3#define _ASM_POWERPC_IRQ_H
   4
   5/*
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the License, or (at your option) any later version.
  10 */
  11
  12#include <linux/threads.h>
  13#include <linux/list.h>
  14#include <linux/radix-tree.h>
  15
  16#include <asm/types.h>
  17#include <asm/atomic.h>
  18
  19
  20/* Define a way to iterate across irqs. */
  21#define for_each_irq(i) \
  22        for ((i) = 0; (i) < NR_IRQS; ++(i))
  23
  24extern atomic_t ppc_n_lost_interrupts;
  25
  26/* This number is used when no interrupt has been assigned */
  27#define NO_IRQ                  (0)
  28
  29/* This is a special irq number to return from get_irq() to tell that
  30 * no interrupt happened _and_ ignore it (don't count it as bad). Some
  31 * platforms like iSeries rely on that.
  32 */
  33#define NO_IRQ_IGNORE           ((unsigned int)-1)
  34
  35/* Total number of virq in the platform */
  36#define NR_IRQS         CONFIG_NR_IRQS
  37
  38/* Number of irqs reserved for the legacy controller */
  39#define NUM_ISA_INTERRUPTS      16
  40
  41/* Same thing, used by the generic IRQ code */
  42#define NR_IRQS_LEGACY          NUM_ISA_INTERRUPTS
  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 */
  48typedef 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 */
  69struct irq_host;
  70struct radix_tree_root;
  71
  72/* Functions below are provided by the host and called whenever a new mapping
  73 * is created or an old mapping is disposed. The host can then proceed to
  74 * whatever internal data structures management is required. It also needs
  75 * to setup the irq_desc when returning from map().
  76 */
  77struct irq_host_ops {
  78        /* Match an interrupt controller device node to a host, returns
  79         * 1 on a match
  80         */
  81        int (*match)(struct irq_host *h, struct device_node *node);
  82
  83        /* Create or update a mapping between a virtual irq number and a hw
  84         * irq number. This is called only once for a given mapping.
  85         */
  86        int (*map)(struct irq_host *h, unsigned int virq, irq_hw_number_t hw);
  87
  88        /* Dispose of such a mapping */
  89        void (*unmap)(struct irq_host *h, unsigned int virq);
  90
  91        /* Translate device-tree interrupt specifier from raw format coming
  92         * from the firmware to a irq_hw_number_t (interrupt line number) and
  93         * type (sense) that can be passed to set_irq_type(). In the absence
  94         * of this callback, irq_create_of_mapping() and irq_of_parse_and_map()
  95         * will return the hw number in the first cell and IRQ_TYPE_NONE for
  96         * the type (which amount to keeping whatever default value the
  97         * interrupt controller has for that line)
  98         */
  99        int (*xlate)(struct irq_host *h, struct device_node *ctrler,
 100                     const u32 *intspec, unsigned int intsize,
 101                     irq_hw_number_t *out_hwirq, unsigned int *out_type);
 102};
 103
 104struct irq_host {
 105        struct list_head        link;
 106
 107        /* type of reverse mapping technique */
 108        unsigned int            revmap_type;
 109#define IRQ_HOST_MAP_LEGACY     0 /* legacy 8259, gets irqs 1..15 */
 110#define IRQ_HOST_MAP_NOMAP      1 /* no fast reverse mapping */
 111#define IRQ_HOST_MAP_LINEAR     2 /* linear map of interrupts */
 112#define IRQ_HOST_MAP_TREE       3 /* radix tree */
 113        union {
 114                struct {
 115                        unsigned int size;
 116                        unsigned int *revmap;
 117                } linear;
 118                struct radix_tree_root tree;
 119        } revmap_data;
 120        struct irq_host_ops     *ops;
 121        void                    *host_data;
 122        irq_hw_number_t         inval_irq;
 123
 124        /* Optional device node pointer */
 125        struct device_node      *of_node;
 126};
 127
 128struct irq_data;
 129extern irq_hw_number_t irqd_to_hwirq(struct irq_data *d);
 130extern irq_hw_number_t virq_to_hw(unsigned int virq);
 131extern bool virq_is_host(unsigned int virq, struct irq_host *host);
 132
 133/**
 134 * irq_alloc_host - Allocate a new irq_host data structure
 135 * @of_node: optional device-tree node of the interrupt controller
 136 * @revmap_type: type of reverse mapping to use
 137 * @revmap_arg: for IRQ_HOST_MAP_LINEAR linear only: size of the map
 138 * @ops: map/unmap host callbacks
 139 * @inval_irq: provide a hw number in that host space that is always invalid
 140 *
 141 * Allocates and initialize and irq_host structure. Note that in the case of
 142 * IRQ_HOST_MAP_LEGACY, the map() callback will be called before this returns
 143 * for all legacy interrupts except 0 (which is always the invalid irq for
 144 * a legacy controller). For a IRQ_HOST_MAP_LINEAR, the map is allocated by
 145 * this call as well. For a IRQ_HOST_MAP_TREE, the radix tree will be allocated
 146 * later during boot automatically (the reverse mapping will use the slow path
 147 * until that happens).
 148 */
 149extern struct irq_host *irq_alloc_host(struct device_node *of_node,
 150                                       unsigned int revmap_type,
 151                                       unsigned int revmap_arg,
 152                                       struct irq_host_ops *ops,
 153                                       irq_hw_number_t inval_irq);
 154
 155
 156/**
 157 * irq_find_host - Locates a host for a given device node
 158 * @node: device-tree node of the interrupt controller
 159 */
 160extern struct irq_host *irq_find_host(struct device_node *node);
 161
 162
 163/**
 164 * irq_set_default_host - Set a "default" host
 165 * @host: default host pointer
 166 *
 167 * For convenience, it's possible to set a "default" host that will be used
 168 * whenever NULL is passed to irq_create_mapping(). It makes life easier for
 169 * platforms that want to manipulate a few hard coded interrupt numbers that
 170 * aren't properly represented in the device-tree.
 171 */
 172extern void irq_set_default_host(struct irq_host *host);
 173
 174
 175/**
 176 * irq_set_virq_count - Set the maximum number of virt irqs
 177 * @count: number of linux virtual irqs, capped with NR_IRQS
 178 *
 179 * This is mainly for use by platforms like iSeries who want to program
 180 * the virtual irq number in the controller to avoid the reverse mapping
 181 */
 182extern void irq_set_virq_count(unsigned int count);
 183
 184
 185/**
 186 * irq_create_mapping - Map a hardware interrupt into linux virq space
 187 * @host: host owning this hardware interrupt or NULL for default host
 188 * @hwirq: hardware irq number in that host space
 189 *
 190 * Only one mapping per hardware interrupt is permitted. Returns a linux
 191 * virq number.
 192 * If the sense/trigger is to be specified, set_irq_type() should be called
 193 * on the number returned from that call.
 194 */
 195extern unsigned int irq_create_mapping(struct irq_host *host,
 196                                       irq_hw_number_t hwirq);
 197
 198
 199/**
 200 * irq_dispose_mapping - Unmap an interrupt
 201 * @virq: linux virq number of the interrupt to unmap
 202 */
 203extern void irq_dispose_mapping(unsigned int virq);
 204
 205/**
 206 * irq_find_mapping - Find a linux virq from an hw irq number.
 207 * @host: host owning this hardware interrupt
 208 * @hwirq: hardware irq number in that host space
 209 *
 210 * This is a slow path, for use by generic code. It's expected that an
 211 * irq controller implementation directly calls the appropriate low level
 212 * mapping function.
 213 */
 214extern unsigned int irq_find_mapping(struct irq_host *host,
 215                                     irq_hw_number_t hwirq);
 216
 217/**
 218 * irq_create_direct_mapping - Allocate a virq for direct mapping
 219 * @host: host to allocate the virq for or NULL for default host
 220 *
 221 * This routine is used for irq controllers which can choose the hardware
 222 * interrupt numbers they generate. In such a case it's simplest to use
 223 * the linux virq as the hardware interrupt number.
 224 */
 225extern unsigned int irq_create_direct_mapping(struct irq_host *host);
 226
 227/**
 228 * irq_radix_revmap_insert - Insert a hw irq to linux virq number mapping.
 229 * @host: host owning this hardware interrupt
 230 * @virq: linux irq number
 231 * @hwirq: hardware irq number in that host space
 232 *
 233 * This is for use by irq controllers that use a radix tree reverse
 234 * mapping for fast lookup.
 235 */
 236extern void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 237                                    irq_hw_number_t hwirq);
 238
 239/**
 240 * irq_radix_revmap_lookup - Find a linux virq from a hw irq number.
 241 * @host: host owning this hardware interrupt
 242 * @hwirq: hardware irq number in that host space
 243 *
 244 * This is a fast path, for use by irq controller code that uses radix tree
 245 * revmaps
 246 */
 247extern unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 248                                            irq_hw_number_t hwirq);
 249
 250/**
 251 * irq_linear_revmap - Find a linux virq from a hw irq number.
 252 * @host: host owning this hardware interrupt
 253 * @hwirq: hardware irq number in that host space
 254 *
 255 * This is a fast path, for use by irq controller code that uses linear
 256 * revmaps. It does fallback to the slow path if the revmap doesn't exist
 257 * yet and will create the revmap entry with appropriate locking
 258 */
 259
 260extern unsigned int irq_linear_revmap(struct irq_host *host,
 261                                      irq_hw_number_t hwirq);
 262
 263
 264
 265/**
 266 * irq_alloc_virt - Allocate virtual irq numbers
 267 * @host: host owning these new virtual irqs
 268 * @count: number of consecutive numbers to allocate
 269 * @hint: pass a hint number, the allocator will try to use a 1:1 mapping
 270 *
 271 * This is a low level function that is used internally by irq_create_mapping()
 272 * and that can be used by some irq controllers implementations for things
 273 * like allocating ranges of numbers for MSIs. The revmaps are left untouched.
 274 */
 275extern unsigned int irq_alloc_virt(struct irq_host *host,
 276                                   unsigned int count,
 277                                   unsigned int hint);
 278
 279/**
 280 * irq_free_virt - Free virtual irq numbers
 281 * @virq: virtual irq number of the first interrupt to free
 282 * @count: number of interrupts to free
 283 *
 284 * This function is the opposite of irq_alloc_virt. It will not clear reverse
 285 * maps, this should be done previously by unmap'ing the interrupt. In fact,
 286 * all interrupts covered by the range being freed should have been unmapped
 287 * prior to calling this.
 288 */
 289extern void irq_free_virt(unsigned int virq, unsigned int count);
 290
 291/**
 292 * irq_early_init - Init irq remapping subsystem
 293 */
 294extern void irq_early_init(void);
 295
 296static __inline__ int irq_canonicalize(int irq)
 297{
 298        return irq;
 299}
 300
 301extern int distribute_irqs;
 302
 303struct irqaction;
 304struct pt_regs;
 305
 306#define __ARCH_HAS_DO_SOFTIRQ
 307
 308#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 309/*
 310 * Per-cpu stacks for handling critical, debug and machine check
 311 * level interrupts.
 312 */
 313extern struct thread_info *critirq_ctx[NR_CPUS];
 314extern struct thread_info *dbgirq_ctx[NR_CPUS];
 315extern struct thread_info *mcheckirq_ctx[NR_CPUS];
 316extern void exc_lvl_ctx_init(void);
 317#else
 318#define exc_lvl_ctx_init()
 319#endif
 320
 321/*
 322 * Per-cpu stacks for handling hard and soft interrupts.
 323 */
 324extern struct thread_info *hardirq_ctx[NR_CPUS];
 325extern struct thread_info *softirq_ctx[NR_CPUS];
 326
 327extern void irq_ctx_init(void);
 328extern void call_do_softirq(struct thread_info *tp);
 329extern int call_handle_irq(int irq, void *p1,
 330                           struct thread_info *tp, void *func);
 331extern void do_IRQ(struct pt_regs *regs);
 332
 333#endif /* _ASM_IRQ_H */
 334#endif /* __KERNEL__ */
 335