arch/powerpc/include/asm/irq.h

   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 <linux/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
  24 extern 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  */
  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
  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  */
  77 struct 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
 104 struct 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
 128 struct irq_data;
 129 extern irq_hw_number_t irqd_to_hwirq(struct irq_data *d);
 130 extern irq_hw_number_t virq_to_hw(unsigned int virq);
 131 extern 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  */
 149 extern 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  */
 160 extern 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  */
 172 extern 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  */
 182 extern 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  */
 195 extern 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  */
 203 extern 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  */
 214 extern 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  */
 225 extern 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  */
 236 extern 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  */
 247 extern 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
 260 extern 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  */
 275 extern 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  */
 289 extern void irq_free_virt(unsigned int virq, unsigned int count);
 290
 291 /**
 292  * irq_early_init - Init irq remapping subsystem
 293  */
 294 extern void irq_early_init(void);
 295
 296 static __inline__ int irq_canonicalize(int irq)
 297 {
 298         return irq;
 299 }
 300
 301 extern int distribute_irqs;
 302
 303 struct irqaction;
 304 struct 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  */
 313 extern struct thread_info *critirq_ctx[NR_CPUS];
 314 extern struct thread_info *dbgirq_ctx[NR_CPUS];
 315 extern struct thread_info *mcheckirq_ctx[NR_CPUS];
 316 extern 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  */
 324 extern struct thread_info *hardirq_ctx[NR_CPUS];
 325 extern struct thread_info *softirq_ctx[NR_CPUS];
 326
 327 extern void irq_ctx_init(void);
 328 extern void call_do_softirq(struct thread_info *tp);
 329 extern int call_handle_irq(int irq, void *p1,
 330                            struct thread_info *tp, void *func);
 331 extern void do_IRQ(struct pt_regs *regs);
 332
 333 int irq_choose_cpu(const struct cpumask *mask);
 334
 335 #endif /* _ASM_IRQ_H */
 336 #endif /* __KERNEL__ */