Merge branch 'irq-core-for-linus' of...

Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  irq: Export functions to allow modular irq drivers
  genirq: Uninline and sanity check generic_handle_irq()
  genirq: Remove pointless ifdefs
  genirq: Make generic irq chip depend on CONFIG_GENERIC_IRQ_CHIP
  genirq: Add chip suspend and resume callbacks
  genirq: Implement a generic interrupt chip
  genirq: Support per-IRQ thread disabling.
  genirq: irq_desc: Document preflow_handler and affinity_hint
  genirq: Update DocBook comments
  genirq: Forgotten updates/deletions after removal of compat code

Documentation/DocBook/genericirq.tmpl

@@ -191,8 +191,8 @@
 	<para>
 	Whenever an interrupt triggers, the lowlevel arch code calls into
 	the generic interrupt code by calling desc->handle_irq().
-	This highlevel IRQ handling function only uses desc->chip primitives
-	referenced by the assigned chip descriptor structure.
+	This highlevel IRQ handling function only uses desc->irq_data.chip
+	primitives referenced by the assigned chip descriptor structure.
 	</para>
     </sect1>
     <sect1 id="Highlevel_Driver_API">
@@ -206,11 +206,11 @@
 	  <listitem><para>enable_irq()</para></listitem>
 	  <listitem><para>disable_irq_nosync() (SMP only)</para></listitem>
 	  <listitem><para>synchronize_irq() (SMP only)</para></listitem>
-	  <listitem><para>set_irq_type()</para></listitem>
-	  <listitem><para>set_irq_wake()</para></listitem>
-	  <listitem><para>set_irq_data()</para></listitem>
-	  <listitem><para>set_irq_chip()</para></listitem>
-	  <listitem><para>set_irq_chip_data()</para></listitem>
+	  <listitem><para>irq_set_irq_type()</para></listitem>
+	  <listitem><para>irq_set_irq_wake()</para></listitem>
+	  <listitem><para>irq_set_handler_data()</para></listitem>
+	  <listitem><para>irq_set_chip()</para></listitem>
+	  <listitem><para>irq_set_chip_data()</para></listitem>
           </itemizedlist>
 	  See the autogenerated function documentation for details.
 	</para>
@@ -225,6 +225,8 @@
 	  <listitem><para>handle_fasteoi_irq</para></listitem>
 	  <listitem><para>handle_simple_irq</para></listitem>
 	  <listitem><para>handle_percpu_irq</para></listitem>
+	  <listitem><para>handle_edge_eoi_irq</para></listitem>
+	  <listitem><para>handle_bad_irq</para></listitem>
 	  </itemizedlist>
 	  The interrupt flow handlers (either predefined or architecture
 	  specific) are assigned to specific interrupts by the architecture
@@ -241,13 +243,13 @@
 		<programlisting>
 default_enable(struct irq_data *data)
 {
-	desc->chip->irq_unmask(data);
+	desc->irq_data.chip->irq_unmask(data);
 }
 
 default_disable(struct irq_data *data)
 {
 	if (!delay_disable(data))
-		desc->chip->irq_mask(data);
+		desc->irq_data.chip->irq_mask(data);
 }
 
 default_ack(struct irq_data *data)
@@ -284,9 +286,9 @@ noop(struct irq_data *data))
 		<para>
 		The following control flow is implemented (simplified excerpt):
 		<programlisting>
-desc->chip->irq_mask();
-handle_IRQ_event(desc->action);
-desc->chip->irq_unmask();
+desc->irq_data.chip->irq_mask_ack();
+handle_irq_event(desc->action);
+desc->irq_data.chip->irq_unmask();
 		</programlisting>
 		</para>
 	    </sect3>
@@ -300,8 +302,8 @@ desc->chip->irq_unmask();
 		<para>
 		The following control flow is implemented (simplified excerpt):
 		<programlisting>
-handle_IRQ_event(desc->action);
-desc->chip->irq_eoi();
+handle_irq_event(desc->action);
+desc->irq_data.chip->irq_eoi();
 		</programlisting>
 		</para>
 	    </sect3>
@@ -315,17 +317,17 @@ desc->chip->irq_eoi();
 		The following control flow is implemented (simplified excerpt):
 		<programlisting>
 if (desc->status &amp; running) {
-	desc->chip->irq_mask();
+	desc->irq_data.chip->irq_mask_ack();
 	desc->status |= pending | masked;
 	return;
 }
-desc->chip->irq_ack();
+desc->irq_data.chip->irq_ack();
 desc->status |= running;
 do {
 	if (desc->status &amp; masked)
-		desc->chip->irq_unmask();
+		desc->irq_data.chip->irq_unmask();
 	desc->status &amp;= ~pending;
-	handle_IRQ_event(desc->action);
+	handle_irq_event(desc->action);
 } while (status &amp; pending);
 desc->status &amp;= ~running;
 		</programlisting>
@@ -344,7 +346,7 @@ desc->status &amp;= ~running;
 		<para>
 		The following control flow is implemented (simplified excerpt):
 		<programlisting>
-handle_IRQ_event(desc->action);
+handle_irq_event(desc->action);
 		</programlisting>
 		</para>
    	    </sect3>
@@ -362,12 +364,29 @@ handle_IRQ_event(desc->action);
 		<para>
 		The following control flow is implemented (simplified excerpt):
 		<programlisting>
-handle_IRQ_event(desc->action);
-if (desc->chip->irq_eoi)
-        desc->chip->irq_eoi();
+if (desc->irq_data.chip->irq_ack)
+	desc->irq_data.chip->irq_ack();
+handle_irq_event(desc->action);
+if (desc->irq_data.chip->irq_eoi)
+        desc->irq_data.chip->irq_eoi();
 		</programlisting>
 		</para>
    	    </sect3>
+	    <sect3 id="EOI_Edge_IRQ_flow_handler">
+	 	<title>EOI Edge IRQ flow handler</title>
+		<para>
+		handle_edge_eoi_irq provides an abnomination of the edge
+		handler which is solely used to tame a badly wreckaged
+		irq controller on powerpc/cell.
+		</para>
+   	    </sect3>
+	    <sect3 id="BAD_IRQ_flow_handler">
+	 	<title>Bad IRQ flow handler</title>
+		<para>
+		handle_bad_irq is used for spurious interrupts which
+		have no real handler assigned..
+		</para>
+   	    </sect3>
 	</sect2>
 	<sect2 id="Quirks_and_optimizations">
 	<title>Quirks and optimizations</title>
@@ -410,6 +429,7 @@ if (desc->chip->irq_eoi)
 	  <listitem><para>irq_mask_ack() - Optional, recommended for performance</para></listitem>
 	  <listitem><para>irq_mask()</para></listitem>
 	  <listitem><para>irq_unmask()</para></listitem>
+	  <listitem><para>irq_eoi() - Optional, required for eoi flow handlers</para></listitem>
 	  <listitem><para>irq_retrigger() - Optional</para></listitem>
 	  <listitem><para>irq_set_type() - Optional</para></listitem>
 	  <listitem><para>irq_set_wake() - Optional</para></listitem>
@@ -424,32 +444,24 @@ if (desc->chip->irq_eoi)
   <chapter id="doirq">
      <title>__do_IRQ entry point</title>
      <para>
- 	The original implementation __do_IRQ() is an alternative entry
-	point for all types of interrupts.
+	The original implementation __do_IRQ() was an alternative entry
+	point for all types of interrupts. It not longer exists.
      </para>
      <para>
 	This handler turned out to be not suitable for all
 	interrupt hardware and was therefore reimplemented with split
-	functionality for egde/level/simple/percpu interrupts. This is not
+	functionality for edge/level/simple/percpu interrupts. This is not
 	only a functional optimization. It also shortens code paths for
 	interrupts.
       </para>
-      <para>
-	To make use of the split implementation, replace the call to
-	__do_IRQ by a call to desc->handle_irq() and associate
-        the appropriate handler function to desc->handle_irq().
-	In most cases the generic handler implementations should
-	be sufficient.
-     </para>
   </chapter>
 
   <chapter id="locking">
      <title>Locking on SMP</title>
      <para>
 	The locking of chip registers is up to the architecture that
-	defines the chip primitives. There is a chip->lock field that can be used
-	for serialization, but the generic layer does not touch it. The per-irq
-	structure is protected via desc->lock, by the generic layer.
+	defines the chip primitives. The per-irq structure is
+	protected via desc->lock, by the generic layer.
      </para>
   </chapter>
   <chapter id="structs">

include/linux/irq.h

@@ -53,12 +53,13 @@ typedef	void (*irq_preflow_handler_t)(struct irq_data *data);
  * Bits which can be modified via irq_set/clear/modify_status_flags()
  * IRQ_LEVEL			- Interrupt is level type. Will be also
  *				  updated in the code when the above trigger
- *				  bits are modified via set_irq_type()
+ *				  bits are modified via irq_set_irq_type()
  * IRQ_PER_CPU			- Mark an interrupt PER_CPU. Will protect
  *				  it from affinity setting
  * IRQ_NOPROBE			- Interrupt cannot be probed by autoprobing
  * IRQ_NOREQUEST		- Interrupt cannot be requested via
  *				  request_irq()
+ * IRQ_NOTHREAD			- Interrupt cannot be threaded
  * IRQ_NOAUTOEN			- Interrupt is not automatically enabled in
  *				  request/setup_irq()
  * IRQ_NO_BALANCING		- Interrupt cannot be balanced (affinity set)
@@ -85,6 +86,7 @@ enum {
 	IRQ_NO_BALANCING	= (1 << 13),
 	IRQ_MOVE_PCNTXT		= (1 << 14),
 	IRQ_NESTED_THREAD	= (1 << 15),
+	IRQ_NOTHREAD		= (1 << 16),
 };
 
 #define IRQF_MODIFY_MASK	\
@@ -261,23 +263,6 @@ static inline void irqd_clr_chained_irq_inprogress(struct irq_data *d)
  * struct irq_chip - hardware interrupt chip descriptor
  *
  * @name:		name for /proc/interrupts
- * @startup:		deprecated, replaced by irq_startup
- * @shutdown:		deprecated, replaced by irq_shutdown
- * @enable:		deprecated, replaced by irq_enable
- * @disable:		deprecated, replaced by irq_disable
- * @ack:		deprecated, replaced by irq_ack
- * @mask:		deprecated, replaced by irq_mask
- * @mask_ack:		deprecated, replaced by irq_mask_ack
- * @unmask:		deprecated, replaced by irq_unmask
- * @eoi:		deprecated, replaced by irq_eoi
- * @end:		deprecated, will go away with __do_IRQ()
- * @set_affinity:	deprecated, replaced by irq_set_affinity
- * @retrigger:		deprecated, replaced by irq_retrigger
- * @set_type:		deprecated, replaced by irq_set_type
- * @set_wake:		deprecated, replaced by irq_wake
- * @bus_lock:		deprecated, replaced by irq_bus_lock
- * @bus_sync_unlock:	deprecated, replaced by irq_bus_sync_unlock
- *
  * @irq_startup:	start up the interrupt (defaults to ->enable if NULL)
  * @irq_shutdown:	shut down the interrupt (defaults to ->disable if NULL)
  * @irq_enable:		enable the interrupt (defaults to chip->unmask if NULL)
@@ -295,6 +280,9 @@ static inline void irqd_clr_chained_irq_inprogress(struct irq_data *d)
  * @irq_bus_sync_unlock:function to sync and unlock slow bus (i2c) chips
  * @irq_cpu_online:	configure an interrupt source for a secondary CPU
  * @irq_cpu_offline:	un-configure an interrupt source for a secondary CPU
+ * @irq_suspend:	function called from core code on suspend once per chip
+ * @irq_resume:		function called from core code on resume once per chip
+ * @irq_pm_shutdown:	function called from core code on shutdown once per chip
  * @irq_print_chip:	optional to print special chip info in show_interrupts
  * @flags:		chip specific flags
  *
@@ -324,6 +312,10 @@ struct irq_chip {
 	void		(*irq_cpu_online)(struct irq_data *data);
 	void		(*irq_cpu_offline)(struct irq_data *data);
 
+	void		(*irq_suspend)(struct irq_data *data);
+	void		(*irq_resume)(struct irq_data *data);
+	void		(*irq_pm_shutdown)(struct irq_data *data);
+
 	void		(*irq_print_chip)(struct irq_data *data, struct seq_file *p);
 
 	unsigned long	flags;
@@ -439,7 +431,7 @@ irq_set_handler(unsigned int irq, irq_flow_handler_t handle)
 /*
  * Set a highlevel chained flow handler for a given IRQ.
  * (a chained handler is automatically enabled and set to
- *  IRQ_NOREQUEST and IRQ_NOPROBE)
+ *  IRQ_NOREQUEST, IRQ_NOPROBE, and IRQ_NOTHREAD)
  */
 static inline void
 irq_set_chained_handler(unsigned int irq, irq_flow_handler_t handle)
@@ -469,6 +461,16 @@ static inline void irq_set_probe(unsigned int irq)
 	irq_modify_status(irq, IRQ_NOPROBE, 0);
 }
 
+static inline void irq_set_nothread(unsigned int irq)
+{
+	irq_modify_status(irq, 0, IRQ_NOTHREAD);
+}
+
+static inline void irq_set_thread(unsigned int irq)
+{
+	irq_modify_status(irq, IRQ_NOTHREAD, 0);
+}
+
 static inline void irq_set_nested_thread(unsigned int irq, bool nest)
 {
 	if (nest)
@@ -573,6 +575,145 @@ static inline int irq_reserve_irq(unsigned int irq)
 	return irq_reserve_irqs(irq, 1);
 }
 
+#ifndef irq_reg_writel
+# define irq_reg_writel(val, addr)	writel(val, addr)
+#endif
+#ifndef irq_reg_readl
+# define irq_reg_readl(addr)		readl(addr)
+#endif
+
+/**
+ * struct irq_chip_regs - register offsets for struct irq_gci
+ * @enable:	Enable register offset to reg_base
+ * @disable:	Disable register offset to reg_base
+ * @mask:	Mask register offset to reg_base
+ * @ack:	Ack register offset to reg_base
+ * @eoi:	Eoi register offset to reg_base
+ * @type:	Type configuration register offset to reg_base
+ * @polarity:	Polarity configuration register offset to reg_base
+ */
+struct irq_chip_regs {
+	unsigned long		enable;
+	unsigned long		disable;
+	unsigned long		mask;
+	unsigned long		ack;
+	unsigned long		eoi;
+	unsigned long		type;
+	unsigned long		polarity;
+};
+
+/**
+ * struct irq_chip_type - Generic interrupt chip instance for a flow type
+ * @chip:		The real interrupt chip which provides the callbacks
+ * @regs:		Register offsets for this chip
+ * @handler:		Flow handler associated with this chip
+ * @type:		Chip can handle these flow types
+ *
+ * A irq_generic_chip can have several instances of irq_chip_type when
+ * it requires different functions and register offsets for different
+ * flow types.
+ */
+struct irq_chip_type {
+	struct irq_chip		chip;
+	struct irq_chip_regs	regs;
+	irq_flow_handler_t	handler;
+	u32			type;
+};
+
+/**
+ * struct irq_chip_generic - Generic irq chip data structure
+ * @lock:		Lock to protect register and cache data access
+ * @reg_base:		Register base address (virtual)
+ * @irq_base:		Interrupt base nr for this chip
+ * @irq_cnt:		Number of interrupts handled by this chip
+ * @mask_cache:		Cached mask register
+ * @type_cache:		Cached type register
+ * @polarity_cache:	Cached polarity register
+ * @wake_enabled:	Interrupt can wakeup from suspend
+ * @wake_active:	Interrupt is marked as an wakeup from suspend source
+ * @num_ct:		Number of available irq_chip_type instances (usually 1)
+ * @private:		Private data for non generic chip callbacks
+ * @list:		List head for keeping track of instances
+ * @chip_types:		Array of interrupt irq_chip_types
+ *
+ * Note, that irq_chip_generic can have multiple irq_chip_type
+ * implementations which can be associated to a particular irq line of
+ * an irq_chip_generic instance. That allows to share and protect
+ * state in an irq_chip_generic instance when we need to implement
+ * different flow mechanisms (level/edge) for it.
+ */
+struct irq_chip_generic {
+	raw_spinlock_t		lock;
+	void __iomem		*reg_base;
+	unsigned int		irq_base;
+	unsigned int		irq_cnt;
+	u32			mask_cache;
+	u32			type_cache;
+	u32			polarity_cache;
+	u32			wake_enabled;
+	u32			wake_active;
+	unsigned int		num_ct;
+	void			*private;
+	struct list_head	list;
+	struct irq_chip_type	chip_types[0];
+};
+
+/**
+ * enum irq_gc_flags - Initialization flags for generic irq chips
+ * @IRQ_GC_INIT_MASK_CACHE:	Initialize the mask_cache by reading mask reg
+ * @IRQ_GC_INIT_NESTED_LOCK:	Set the lock class of the irqs to nested for
+ *				irq chips which need to call irq_set_wake() on
+ *				the parent irq. Usually GPIO implementations
+ */
+enum irq_gc_flags {
+	IRQ_GC_INIT_MASK_CACHE		= 1 << 0,
+	IRQ_GC_INIT_NESTED_LOCK		= 1 << 1,
+};
+
+/* Generic chip callback functions */
+void irq_gc_noop(struct irq_data *d);
+void irq_gc_mask_disable_reg(struct irq_data *d);
+void irq_gc_mask_set_bit(struct irq_data *d);
+void irq_gc_mask_clr_bit(struct irq_data *d);
+void irq_gc_unmask_enable_reg(struct irq_data *d);
+void irq_gc_ack(struct irq_data *d);
+void irq_gc_mask_disable_reg_and_ack(struct irq_data *d);
+void irq_gc_eoi(struct irq_data *d);
+int irq_gc_set_wake(struct irq_data *d, unsigned int on);
+
+/* Setup functions for irq_chip_generic */
+struct irq_chip_generic *
+irq_alloc_generic_chip(const char *name, int nr_ct, unsigned int irq_base,
+		       void __iomem *reg_base, irq_flow_handler_t handler);
+void irq_setup_generic_chip(struct irq_chip_generic *gc, u32 msk,
+			    enum irq_gc_flags flags, unsigned int clr,
+			    unsigned int set);
+int irq_setup_alt_chip(struct irq_data *d, unsigned int type);
+void irq_remove_generic_chip(struct irq_chip_generic *gc, u32 msk,
+			     unsigned int clr, unsigned int set);
+
+static inline struct irq_chip_type *irq_data_get_chip_type(struct irq_data *d)
+{
+	return container_of(d->chip, struct irq_chip_type, chip);
+}
+
+#define IRQ_MSK(n) (u32)((n) < 32 ? ((1 << (n)) - 1) : UINT_MAX)
+
+#ifdef CONFIG_SMP
+static inline void irq_gc_lock(struct irq_chip_generic *gc)
+{
+	raw_spin_lock(&gc->lock);
+}
+
+static inline void irq_gc_unlock(struct irq_chip_generic *gc)
+{
+	raw_spin_unlock(&gc->lock);
+}
+#else
+static inline void irq_gc_lock(struct irq_chip_generic *gc) { }
+static inline void irq_gc_unlock(struct irq_chip_generic *gc) { }
+#endif
+
 #endif /* CONFIG_GENERIC_HARDIRQS */
 
 #endif /* !CONFIG_S390 */

include/linux/irqdesc.h

@@ -16,16 +16,18 @@ struct timer_rand_state;
  * @irq_data:		per irq and chip data passed down to chip functions
  * @timer_rand_state:	pointer to timer rand state struct
  * @kstat_irqs:		irq stats per cpu
- * @handle_irq:		highlevel irq-events handler [if NULL, __do_IRQ()]
+ * @handle_irq:		highlevel irq-events handler
+ * @preflow_handler:	handler called before the flow handler (currently used by sparc)
  * @action:		the irq action chain
  * @status:		status information
  * @core_internal_state__do_not_mess_with_it: core internal status information
  * @depth:		disable-depth, for nested irq_disable() calls
- * @wake_depth:		enable depth, for multiple set_irq_wake() callers
+ * @wake_depth:		enable depth, for multiple irq_set_irq_wake() callers
  * @irq_count:		stats field to detect stalled irqs
  * @last_unhandled:	aging timer for unhandled count
  * @irqs_unhandled:	stats field for spurious unhandled interrupts
  * @lock:		locking for SMP
+ * @affinity_hint:	hint to user space for preferred irq affinity
  * @affinity_notify:	context for notification of affinity changes
  * @pending_mask:	pending rebalanced interrupts
  * @threads_oneshot:	bitfield to handle shared oneshot threads
@@ -109,10 +111,7 @@ static inline void generic_handle_irq_desc(unsigned int irq, struct irq_desc *de
 	desc->handle_irq(irq, desc);
 }
 
-static inline void generic_handle_irq(unsigned int irq)
-{
-	generic_handle_irq_desc(irq, irq_to_desc(irq));
-}
+int generic_handle_irq(unsigned int irq);
 
 /* Test to see if a driver has successfully requested an irq */
 static inline int irq_has_action(unsigned int irq)

kernel/irq/Kconfig

@@ -48,6 +48,10 @@ config IRQ_PREFLOW_FASTEOI
 config IRQ_EDGE_EOI_HANDLER
        bool
 
+# Generic configurable interrupt chip implementation
+config GENERIC_IRQ_CHIP
+       bool
+
 # Support forced irq threading
 config IRQ_FORCED_THREADING
        bool

kernel/irq/Makefile

 
 obj-y := irqdesc.o handle.o manage.o spurious.o resend.o chip.o dummychip.o devres.o
+obj-$(CONFIG_GENERIC_IRQ_CHIP) += generic-chip.o
 obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o

kernel/irq/chip.c

@@ -310,6 +310,7 @@ handle_simple_irq(unsigned int irq, struct irq_desc *desc)
 out_unlock:
 	raw_spin_unlock(&desc->lock);
 }
+EXPORT_SYMBOL_GPL(handle_simple_irq);
 
 /**
  *	handle_level_irq - Level type irq handler
@@ -573,6 +574,7 @@ __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 	if (handle != handle_bad_irq && is_chained) {
 		irq_settings_set_noprobe(desc);
 		irq_settings_set_norequest(desc);
+		irq_settings_set_nothread(desc);
 		irq_startup(desc);
 	}
 out:
@@ -612,6 +614,7 @@ void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
 
 	irq_put_desc_unlock(desc, flags);
 }
+EXPORT_SYMBOL_GPL(irq_modify_status);
 
 /**
  *	irq_cpu_online - Invoke all irq_cpu_online functions.

kernel/irq/debug.h

@@ -27,6 +27,7 @@ static inline void print_irq_desc(unsigned int irq, struct irq_desc *desc)
 	P(IRQ_PER_CPU);
 	P(IRQ_NOPROBE);
 	P(IRQ_NOREQUEST);
+	P(IRQ_NOTHREAD);
 	P(IRQ_NOAUTOEN);
 
 	PS(IRQS_AUTODETECT);

kernel/irq/generic-chip.c

+/*
+ * Library implementing the most common irq chip callback functions
+ *
+ * Copyright (C) 2011, Thomas Gleixner
+ */
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <linux/syscore_ops.h>
+
+#include "internals.h"
+
+static LIST_HEAD(gc_list);
+static DEFINE_RAW_SPINLOCK(gc_lock);
+
+static inline struct irq_chip_regs *cur_regs(struct irq_data *d)
+{
+	return &container_of(d->chip, struct irq_chip_type, chip)->regs;
+}
+
+/**
+ * irq_gc_noop - NOOP function
+ * @d: irq_data
+ */
+void irq_gc_noop(struct irq_data *d)
+{
+}
+
+/**
+ * irq_gc_mask_disable_reg - Mask chip via disable register
+ * @d: irq_data
+ *
+ * Chip has separate enable/disable registers instead of a single mask
+ * register.
+ */
+void irq_gc_mask_disable_reg(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	u32 mask = 1 << (d->irq - gc->irq_base);
+
+	irq_gc_lock(gc);
+	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->disable);
+	gc->mask_cache &= ~mask;
+	irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_mask_set_mask_bit - Mask chip via setting bit in mask register
+ * @d: irq_data
+ *
+ * Chip has a single mask register. Values of this register are cached
+ * and protected by gc->lock
+ */
+void irq_gc_mask_set_bit(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	u32 mask = 1 << (d->irq - gc->irq_base);
+
+	irq_gc_lock(gc);
+	gc->mask_cache |= mask;
+	irq_reg_writel(gc->mask_cache, gc->reg_base + cur_regs(d)->mask);
+	irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_mask_set_mask_bit - Mask chip via clearing bit in mask register
+ * @d: irq_data
+ *
+ * Chip has a single mask register. Values of this register are cached
+ * and protected by gc->lock
+ */
+void irq_gc_mask_clr_bit(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	u32 mask = 1 << (d->irq - gc->irq_base);
+
+	irq_gc_lock(gc);
+	gc->mask_cache &= ~mask;
+	irq_reg_writel(gc->mask_cache, gc->reg_base + cur_regs(d)->mask);
+	irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_unmask_enable_reg - Unmask chip via enable register
+ * @d: irq_data
+ *
+ * Chip has separate enable/disable registers instead of a single mask
+ * register.
+ */
+void irq_gc_unmask_enable_reg(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	u32 mask = 1 << (d->irq - gc->irq_base);
+
+	irq_gc_lock(gc);
+	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->enable);
+	gc->mask_cache |= mask;
+	irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_ack - Ack pending interrupt
+ * @d: irq_data
+ */
+void irq_gc_ack(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	u32 mask = 1 << (d->irq - gc->irq_base);
+
+	irq_gc_lock(gc);
+	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->ack);
+	irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_mask_disable_reg_and_ack- Mask and ack pending interrupt
+ * @d: irq_data
+ */
+void irq_gc_mask_disable_reg_and_ack(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	u32 mask = 1 << (d->irq - gc->irq_base);
+
+	irq_gc_lock(gc);
+	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->mask);
+	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->ack);
+	irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_eoi - EOI interrupt
+ * @d: irq_data
+ */
+void irq_gc_eoi(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	u32 mask = 1 << (d->irq - gc->irq_base);
+
+	irq_gc_lock(gc);
+	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->eoi);
+	irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_set_wake - Set/clr wake bit for an interrupt
+ * @d: irq_data
+ *
+ * For chips where the wake from suspend functionality is not
+ * configured in a separate register and the wakeup active state is
+ * just stored in a bitmask.
+ */
+int irq_gc_set_wake(struct irq_data *d, unsigned int on)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	u32 mask = 1 << (d->irq - gc->irq_base);
+
+	if (!(mask & gc->wake_enabled))
+		return -EINVAL;
+
+	irq_gc_lock(gc);
+	if (on)
+		gc->wake_active |= mask;
+	else
+		gc->wake_active &= ~mask;
+	irq_gc_unlock(gc);
+	return 0;
+}
+
+/**
+ * irq_alloc_generic_chip - Allocate a generic chip and initialize it
+ * @name:	Name of the irq chip
+ * @num_ct:	Number of irq_chip_type instances associated with this
+ * @irq_base:	Interrupt base nr for this chip
+ * @reg_base:	Register base address (virtual)
+ * @handler:	Default flow handler associated with this chip
+ *
+ * Returns an initialized irq_chip_generic structure. The chip defaults
+ * to the primary (index 0) irq_chip_type and @handler
+ */
+struct irq_chip_generic *
+irq_alloc_generic_chip(const char *name, int num_ct, unsigned int irq_base,
+		       void __iomem *reg_base, irq_flow_handler_t handler)
+{
+	struct irq_chip_generic *gc;
+	unsigned long sz = sizeof(*gc) + num_ct * sizeof(struct irq_chip_type);
+
+	gc = kzalloc(sz, GFP_KERNEL);
+	if (gc) {
+		raw_spin_lock_init(&gc->lock);
+		gc->num_ct = num_ct;
+		gc->irq_base = irq_base;
+		gc->reg_base = reg_base;
+		gc->chip_types->chip.name = name;
+		gc->chip_types->handler = handler;
+	}
+	return gc;
+}
+
+/*
+ * Separate lockdep class for interrupt chip which can nest irq_desc
+ * lock.
+ */
+static struct lock_class_key irq_nested_lock_class;
+
+/**
+ * irq_setup_generic_chip - Setup a range of interrupts with a generic chip
+ * @gc:		Generic irq chip holding all data
+ * @msk:	Bitmask holding the irqs to initialize relative to gc->irq_base
+ * @flags:	Flags for initialization
+ * @clr:	IRQ_* bits to clear
+ * @set:	IRQ_* bits to set
+ *
+ * Set up max. 32 interrupts starting from gc->irq_base. Note, this
+ * initializes all interrupts to the primary irq_chip_type and its
+ * associated handler.
+ */
+void irq_setup_generic_chip(struct irq_chip_generic *gc, u32 msk,
+			    enum irq_gc_flags flags, unsigned int clr,
+			    unsigned int set)
+{
+	struct irq_chip_type *ct = gc->chip_types;
+	unsigned int i;
+
+	raw_spin_lock(&gc_lock);
+	list_add_tail(&gc->list, &gc_list);
+	raw_spin_unlock(&gc_lock);
+
+	/* Init mask cache ? */
+	if (flags & IRQ_GC_INIT_MASK_CACHE)
+		gc->mask_cache = irq_reg_readl(gc->reg_base + ct->regs.mask);
+
+	for (i = gc->irq_base; msk; msk >>= 1, i++) {
+		if (!msk & 0x01)
+			continue;
+
+		if (flags & IRQ_GC_INIT_NESTED_LOCK)
+			irq_set_lockdep_class(i, &irq_nested_lock_class);
+
+		irq_set_chip_and_handler(i, &ct->chip, ct->handler);
+		irq_set_chip_data(i, gc);
+		irq_modify_status(i, clr, set);
+	}
+	gc->irq_cnt = i - gc->irq_base;
+}
+
+/**
+ * irq_setup_alt_chip - Switch to alternative chip
+ * @d:		irq_data for this interrupt
+ * @type	Flow type to be initialized
+ *
+ * Only to be called from chip->irq_set_type() callbacks.
+ */
+int irq_setup_alt_chip(struct irq_data *d, unsigned int type)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct irq_chip_type *ct = gc->chip_types;
+	unsigned int i;
+
+	for (i = 0; i < gc->num_ct; i++, ct++) {
+		if (ct->type & type) {
+			d->chip = &ct->chip;
+			irq_data_to_desc(d)->handle_irq = ct->handler;
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+/**
+ * irq_remove_generic_chip - Remove a chip
+ * @gc:		Generic irq chip holding all data
+ * @msk:	Bitmask holding the irqs to initialize relative to gc->irq_base
+ * @clr:	IRQ_* bits to clear
+ * @set:	IRQ_* bits to set
+ *
+ * Remove up to 32 interrupts starting from gc->irq_base.
+ */
+void irq_remove_generic_chip(struct irq_chip_generic *gc, u32 msk,
+			     unsigned int clr, unsigned int set)
+{
+	unsigned int i = gc->irq_base;
+
+	raw_spin_lock(&gc_lock);
+	list_del(&gc->list);
+	raw_spin_unlock(&gc_lock);
+
+	for (; msk; msk >>= 1, i++) {
+		if (!msk & 0x01)
+			continue;
+
+		/* Remove handler first. That will mask the irq line */
+		irq_set_handler(i, NULL);
+		irq_set_chip(i, &no_irq_chip);
+		irq_set_chip_data(i, NULL);
+		irq_modify_status(i, clr, set);
+	}
+}
+
+#ifdef CONFIG_PM
+static int irq_gc_suspend(void)
+{
+	struct irq_chip_generic *gc;
+
+	list_for_each_entry(gc, &gc_list, list) {
+		struct irq_chip_type *ct = gc->chip_types;
+
+		if (ct->chip.irq_suspend)
+			ct->chip.irq_suspend(irq_get_irq_data(gc->irq_base));
+	}
+	return 0;
+}
+
+static void irq_gc_resume(void)
+{
+	struct irq_chip_generic *gc;
+
+	list_for_each_entry(gc, &gc_list, list) {
+		struct irq_chip_type *ct = gc->chip_types;
+
+		if (ct->chip.irq_resume)
+			ct->chip.irq_resume(irq_get_irq_data(gc->irq_base));
+	}
+}
+#else
+#define irq_gc_suspend NULL
+#define irq_gc_resume NULL
+#endif
+
+static void irq_gc_shutdown(void)
+{
+	struct irq_chip_generic *gc;
+
+	list_for_each_entry(gc, &gc_list, list) {
+		struct irq_chip_type *ct = gc->chip_types;
+
+		if (ct->chip.irq_pm_shutdown)
+			ct->chip.irq_pm_shutdown(irq_get_irq_data(gc->irq_base));
+	}
+}
+
+static struct syscore_ops irq_gc_syscore_ops = {
+	.suspend = irq_gc_suspend,
+	.resume = irq_gc_resume,
+	.shutdown = irq_gc_shutdown,
+};
+
+static int __init irq_gc_init_ops(void)
+{
+	register_syscore_ops(&irq_gc_syscore_ops);
+	return 0;
+}
+device_initcall(irq_gc_init_ops);

kernel/irq/irqdesc.c

@@ -22,7 +22,7 @@
  */
 static struct lock_class_key irq_desc_lock_class;
 
-#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
+#if defined(CONFIG_SMP)
 static void __init init_irq_default_affinity(void)
 {
 	alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
@@ -290,6 +290,22 @@ static int irq_expand_nr_irqs(unsigned int nr)
 
 #endif /* !CONFIG_SPARSE_IRQ */
 
+/**
+ * generic_handle_irq - Invoke the handler for a particular irq
+ * @irq:	The irq number to handle
+ *
+ */
+int generic_handle_irq(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	if (!desc)
+		return -EINVAL;
+	generic_handle_irq_desc(irq, desc);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(generic_handle_irq);
+
 /* Dynamic interrupt handling */
 
 /**
@@ -311,6 +327,7 @@ void irq_free_descs(unsigned int from, unsigned int cnt)
 	bitmap_clear(allocated_irqs, from, cnt);
 	mutex_unlock(&sparse_irq_lock);
 }
+EXPORT_SYMBOL_GPL(irq_free_descs);
 
 /**
  * irq_alloc_descs - allocate and initialize a range of irq descriptors
@@ -351,6 +368,7 @@ irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node)
 	mutex_unlock(&sparse_irq_lock);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(irq_alloc_descs);
 
 /**
  * irq_reserve_irqs - mark irqs allocated
@@ -430,7 +448,6 @@ unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 }
 
-#ifdef CONFIG_GENERIC_HARDIRQS
 unsigned int kstat_irqs(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
@@ -443,4 +460,3 @@ unsigned int kstat_irqs(unsigned int irq)
 		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 	return sum;
 }
-#endif /* CONFIG_GENERIC_HARDIRQS */

kernel/irq/manage.c

@@ -900,7 +900,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 		 */
 		new->handler = irq_nested_primary_handler;
 	} else {
-		irq_setup_forced_threading(new);
+		if (irq_settings_can_thread(desc))
+			irq_setup_forced_threading(new);
 	}
 
 	/*

kernel/irq/settings.h

@@ -8,6 +8,7 @@ enum {
 	_IRQ_LEVEL		= IRQ_LEVEL,
 	_IRQ_NOPROBE		= IRQ_NOPROBE,
 	_IRQ_NOREQUEST		= IRQ_NOREQUEST,
+	_IRQ_NOTHREAD		= IRQ_NOTHREAD,
 	_IRQ_NOAUTOEN		= IRQ_NOAUTOEN,
 	_IRQ_MOVE_PCNTXT	= IRQ_MOVE_PCNTXT,
 	_IRQ_NO_BALANCING	= IRQ_NO_BALANCING,
@@ -20,6 +21,7 @@ enum {
 #define IRQ_LEVEL		GOT_YOU_MORON
 #define IRQ_NOPROBE		GOT_YOU_MORON
 #define IRQ_NOREQUEST		GOT_YOU_MORON
+#define IRQ_NOTHREAD		GOT_YOU_MORON
 #define IRQ_NOAUTOEN		GOT_YOU_MORON
 #define IRQ_NESTED_THREAD	GOT_YOU_MORON
 #undef IRQF_MODIFY_MASK
@@ -94,6 +96,21 @@ static inline void irq_settings_set_norequest(struct irq_desc *desc)
 	desc->status_use_accessors |= _IRQ_NOREQUEST;
 }
 
+static inline bool irq_settings_can_thread(struct irq_desc *desc)
+{
+	return !(desc->status_use_accessors & _IRQ_NOTHREAD);
+}
+
+static inline void irq_settings_clr_nothread(struct irq_desc *desc)
+{
+	desc->status_use_accessors &= ~_IRQ_NOTHREAD;
+}
+
+static inline void irq_settings_set_nothread(struct irq_desc *desc)
+{
+	desc->status_use_accessors |= _IRQ_NOTHREAD;
+}
+
 static inline bool irq_settings_can_probe(struct irq_desc *desc)
 {
 	return !(desc->status_use_accessors & _IRQ_NOPROBE);