[PATCH] genirq: core

Core genirq support: add the irq-chip and irq-flow abstractions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

7 files changed, 182 insertions, 22 deletions

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 14d7e94048dd..437f2c635db6 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -43,20 +43,36 @@
 #define IRQ_NOPROBE     512     /* IRQ is not valid for probing */
 #define IRQ_NOREQUEST   1024    /* IRQ cannot be requested */
 #define IRQ_NOAUTOEN    2048    /* IRQ will not be enabled on request irq */
+#define IRQ_DELAYED_DISABLE \
+                        4096    /* IRQ disable (masking) happens delayed. */
+
+/*
+ * IRQ types, see also include/linux/interrupt.h
+ */
+#define IRQ_TYPE_NONE           0x0000          /* Default, unspecified type */
+#define IRQ_TYPE_EDGE_RISING    0x0001          /* Edge rising type */
+#define IRQ_TYPE_EDGE_FALLING   0x0002          /* Edge falling type */
+#define IRQ_TYPE_EDGE_BOTH (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)
+#define IRQ_TYPE_LEVEL_HIGH     0x0004          /* Level high type */
+#define IRQ_TYPE_LEVEL_LOW      0x0008          /* Level low type */
+#define IRQ_TYPE_SIMPLE         0x0010          /* Simple type */
+#define IRQ_TYPE_PERCPU         0x0020          /* Per CPU type */
+#define IRQ_TYPE_PROBE          0x0040          /* Probing in progress */
+
+struct proc_dir_entry;
+
 /**
- * struct hw_interrupt_type - hardware interrupt type descriptor
+ * struct irq_chip - hardware interrupt chip descriptor
  *
  * @name:               name for /proc/interrupts
  * @startup:            start up the interrupt (defaults to ->enable if NULL)
  * @shutdown:           shut down the interrupt (defaults to ->disable if NULL)
  * @enable:             enable the interrupt (defaults to chip->unmask if NULL)
  * @disable:            disable the interrupt (defaults to chip->mask if NULL)
- * @handle_irq:         irq flow handler called from the arch IRQ glue code
  * @ack:                start of a new interrupt
  * @mask:               mask an interrupt source
  * @mask_ack:           ack and mask an interrupt source
  * @unmask:             unmask an interrupt source
- * @hold:               same interrupt while the handler is running
  * @end:                end of interrupt
  * @set_affinity:       set the CPU affinity on SMP machines
  * @retrigger:          resend an IRQ to the CPU
@@ -64,33 +80,45 @@
  * @set_wake:           enable/disable power-management wake-on of an IRQ
  *
  * @release:            release function solely used by UML
+ * @typename:           obsoleted by name, kept as migration helper
  */
-struct hw_interrupt_type {
-        const char      *typename;
+struct irq_chip {
+        const char      *name;
         unsigned int    (*startup)(unsigned int irq);
         void            (*shutdown)(unsigned int irq);
         void            (*enable)(unsigned int irq);
         void            (*disable)(unsigned int irq);
+
         void            (*ack)(unsigned int irq);
+        void            (*mask)(unsigned int irq);
+        void            (*mask_ack)(unsigned int irq);
+        void            (*unmask)(unsigned int irq);
+
         void            (*end)(unsigned int irq);
         void            (*set_affinity)(unsigned int irq, cpumask_t dest);
         int             (*retrigger)(unsigned int irq);
+        int             (*set_type)(unsigned int irq, unsigned int flow_type);
+        int             (*set_wake)(unsigned int irq, unsigned int on);
 
         /* Currently used only by UML, might disappear one day.*/
 #ifdef CONFIG_IRQ_RELEASE_METHOD
         void            (*release)(unsigned int irq, void *dev_id);
 #endif
+        /*
+         * For compatibility, ->typename is copied into ->name.
+         * Will disappear.
+         */
+        const char      *typename;
 };
 
-typedef struct hw_interrupt_type  hw_irq_controller;
-
-struct proc_dir_entry;
-
 /**
  * struct irq_desc - interrupt descriptor
  *
- * @handler:            interrupt type dependent handler functions
- * @handler_data:       data for the type handlers
+ * @handle_irq:         highlevel irq-events handler [if NULL, __do_IRQ()]
+ * @chip:               low level interrupt hardware access
+ * @handler_data:       per-IRQ data for the irq_chip methods
+ * @chip_data:          platform-specific per-chip private data for the chip
+ *                      methods, to allow shared chip implementations
  * @action:             the irq action chain
  * @status:             status information
  * @depth:              disable-depth, for nested irq_disable() calls
@@ -98,6 +126,7 @@ struct proc_dir_entry;
  * @irqs_unhandled:     stats field for spurious unhandled interrupts
  * @lock:               locking for SMP
  * @affinity:           IRQ affinity on SMP
+ * @cpu:                cpu index useful for balancing
  * @pending_mask:       pending rebalanced interrupts
  * @move_irq:           need to re-target IRQ destination
  * @dir:                /proc/irq/ procfs entry
@@ -106,16 +135,22 @@ struct proc_dir_entry;
  * Pad this out to 32 bytes for cache and indexing reasons.
  */
 struct irq_desc {
-        hw_irq_controller       *chip;
+        void fastcall           (*handle_irq)(unsigned int irq,
+                                              struct irq_desc *desc,
+                                              struct pt_regs *regs);
+        struct irq_chip         *chip;
+        void                    *handler_data;
         void                    *chip_data;
         struct irqaction        *action;        /* IRQ action list */
         unsigned int            status;         /* IRQ status */
+
         unsigned int            depth;          /* nested irq disables */
         unsigned int            irq_count;      /* For detecting broken IRQs */
         unsigned int            irqs_unhandled;
         spinlock_t              lock;
 #ifdef CONFIG_SMP
         cpumask_t               affinity;
+        unsigned int            cpu;
 #endif
 #if defined(CONFIG_GENERIC_PENDING_IRQ) || defined(CONFIG_IRQBALANCE)
         cpumask_t               pending_mask;
@@ -131,6 +166,9 @@ extern struct irq_desc irq_desc[NR_IRQS];
 /*
  * Migration helpers for obsolete names, they will go away:
  */
+#define hw_interrupt_type       irq_chip
+typedef struct irq_chip         hw_irq_controller;
+#define no_irq_type             no_irq_chip
 typedef struct irq_desc         irq_desc_t;
 
 /*
@@ -138,6 +176,17 @@ typedef struct irq_desc		irq_desc_t;
  */
 #include <asm/hw_irq.h>
 
+/*
+ * Architectures call this to let the generic IRQ layer
+ * handle an interrupt:
+ */
+static inline void generic_handle_irq(unsigned int irq, struct pt_regs *regs)
+{
+        struct irq_desc *desc = irq_desc + irq;
+
+        desc->handle_irq(irq, desc, regs);
+}
+
 extern int setup_irq(unsigned int irq, struct irqaction *new);
 
 #ifdef CONFIG_GENERIC_HARDIRQS
@@ -236,27 +285,100 @@ static inline int select_smp_affinity(unsigned int irq)
 #endif
 
 extern int no_irq_affinity;
-extern int noirqdebug_setup(char *str);
 
-extern irqreturn_t handle_IRQ_event(unsigned int irq, struct pt_regs *regs,
-                                    struct irqaction *action);
+/* Handle irq action chains: */
+extern int handle_IRQ_event(unsigned int irq, struct pt_regs *regs,
+                            struct irqaction *action);
+
+/*
+ * Built-in IRQ handlers for various IRQ types,
+ * callable via desc->chip->handle_irq()
+ */
+extern void fastcall
+handle_level_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs);
+extern void fastcall
+handle_fastack_irq(unsigned int irq, struct irq_desc *desc,
+                         struct pt_regs *regs);
+extern void fastcall
+handle_edge_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs);
+extern void fastcall
+handle_simple_irq(unsigned int irq, struct irq_desc *desc,
+                  struct pt_regs *regs);
+extern void fastcall
+handle_percpu_irq(unsigned int irq, struct irq_desc *desc,
+                  struct pt_regs *regs);
+extern void fastcall
+handle_bad_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs);
+
+/*
+ * Get a descriptive string for the highlevel handler, for
+ * /proc/interrupts output:
+ */
+extern const char *
+handle_irq_name(void fastcall (*handle)(unsigned int, struct irq_desc *,
+                                        struct pt_regs *));
+
 /*
- * Explicit fastcall, because i386 4KSTACKS calls it from assembly:
+ * Monolithic do_IRQ implementation.
+ * (is an explicit fastcall, because i386 4KSTACKS calls it from assembly)
  */
 extern fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs);
 
+/* Handling of unhandled and spurious interrupts: */
 extern void note_interrupt(unsigned int irq, struct irq_desc *desc,
                            int action_ret, struct pt_regs *regs);
-extern int can_request_irq(unsigned int irq, unsigned long irqflags);
 
 /* Resending of interrupts :*/
 void check_irq_resend(struct irq_desc *desc, unsigned int irq);
 
+/* Initialize /proc/irq/ */
 extern void init_irq_proc(void);
 
-#endif /* CONFIG_GENERIC_HARDIRQS */
+/* Enable/disable irq debugging output: */
+extern int noirqdebug_setup(char *str);
+
+/* Checks whether the interrupt can be requested by request_irq(): */
+extern int can_request_irq(unsigned int irq, unsigned long irqflags);
+
+/* Dummy irq-chip implementation: */
+extern struct irq_chip no_irq_chip;
+
+extern void
+set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
+                         void fastcall (*handle)(unsigned int,
+                                                 struct irq_desc *,
+                                                 struct pt_regs *));
+extern void
+__set_irq_handler(unsigned int irq,
+                  void fastcall (*handle)(unsigned int, struct irq_desc *,
+                                          struct pt_regs *),
+                  int is_chained);
 
-extern hw_irq_controller no_irq_type;  /* needed in every arch ? */
+/*
+ * Set a highlevel flow handler for a given IRQ:
+ */
+static inline void
+set_irq_handler(unsigned int irq,
+                void fastcall (*handle)(unsigned int, struct irq_desc *,
+                                        struct pt_regs *))
+{
+        __set_irq_handler(irq, handle, 0);
+}
+
+/*
+ * Set a highlevel chained flow handler for a given IRQ.
+ * (a chained handler is automatically enabled and set to
+ *  IRQ_NOREQUEST and IRQ_NOPROBE)
+ */
+static inline void
+set_irq_chained_handler(unsigned int irq,
+                        void fastcall (*handle)(unsigned int, struct irq_desc *,
+                                                struct pt_regs *))
+{
+        __set_irq_handler(irq, handle, 1);
+}
+
+#endif /* CONFIG_GENERIC_HARDIRQS */
 
 #endif /* !CONFIG_S390 */
 
diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c
index ed98c7d46cf2..cfdb63eb5c94 100644
--- a/kernel/irq/autoprobe.c
+++ b/kernel/irq/autoprobe.c
@@ -40,8 +40,15 @@ unsigned long probe_irq_on(void)
                 desc = irq_desc + i;
 
                 spin_lock_irq(&desc->lock);
-                if (!desc->action && !(desc->status & IRQ_NOPROBE))
+                if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
+                        /*
+                         * Some chips need to know about probing in
+                         * progress:
+                         */
+                        if (desc->chip->set_type)
+                                desc->chip->set_type(i, IRQ_TYPE_PROBE);
                         desc->chip->startup(i);
+                }
                 spin_unlock_irq(&desc->lock);
         }
 
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index bddcb8f5fea4..a04b516afa59 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -18,6 +18,16 @@
 
 #include "internals.h"
 
+/**
+ * handle_bad_irq - handle spurious and unhandled irqs
+ */
+void fastcall
+handle_bad_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs)
+{
+        kstat_this_cpu.irqs[irq]++;
+        ack_bad_irq(irq);
+}
+
 /*
  * Linux has a controller-independent interrupt architecture.
  * Every controller has a 'controller-template', that is used
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 46feba630266..2ba8ae3c8e96 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -4,6 +4,12 @@
 
 extern int noirqdebug;
 
+/* Set default functions for irq_chip structures: */
+extern void irq_chip_set_defaults(struct irq_chip *chip);
+
+/* Set default handler: */
+extern void compat_irq_chip_set_default_handler(struct irq_desc *desc);
+
 #ifdef CONFIG_PROC_FS
 extern void register_irq_proc(unsigned int irq);
 extern void register_handler_proc(unsigned int irq, struct irqaction *action);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 1a2e7663096a..b61784ee78b2 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -153,6 +153,17 @@ int can_request_irq(unsigned int irq, unsigned long irqflags)
         return !action;
 }
 
+void compat_irq_chip_set_default_handler(struct irq_desc *desc)
+{
+        /*
+         * If the architecture still has not overriden
+         * the flow handler then zap the default. This
+         * should catch incorrect flow-type setting.
+         */
+        if (desc->handle_irq == &handle_bad_irq)
+                desc->handle_irq = NULL;
+}
+
 /*
  * Internal function to register an irqaction - typically used to
  * allocate special interrupts that are part of the architecture.
@@ -217,6 +228,9 @@ int setup_irq(unsigned int irq, struct irqaction *new)
                 desc->status |= IRQ_PER_CPU;
 #endif
         if (!shared) {
+                irq_chip_set_defaults(desc->chip);
+                compat_irq_chip_set_default_handler(desc);
+
                 desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING |
                                   IRQ_INPROGRESS);
 
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c
index 096b102fb392..872f91ba2ce8 100644
--- a/kernel/irq/resend.c
+++ b/kernel/irq/resend.c
@@ -37,9 +37,9 @@ static void resend_irqs(unsigned long arg)
                 irq = find_first_bit(irqs_resend, NR_IRQS);
                 clear_bit(irq, irqs_resend);
                 desc = irq_desc + irq;
-                spin_lock_irqsave(&desc->lock, flags);
+                local_irq_disable();
                 desc->handle_irq(irq, desc, NULL);
-                spin_unlock_irqrestore(&desc->lock, flags);
+                local_irq_enable();
         }
 }
 
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 3a0a62123301..ca187b83f897 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -168,6 +168,7 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc,
                  */
                 printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
                 desc->status |= IRQ_DISABLED;
+                desc->depth = 1;
                 desc->chip->disable(irq);
         }
         desc->irqs_unhandled = 0;