8 files changed, 401 insertions, 4 deletions

diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index c574f9a12c48..d1d051b38e0b 100644
--- a/kernel/irq/Kconfig
+++ b/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
diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
index 54329cd7b3ee..73290056cfb6 100644
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -1,5 +1,6 @@
 
 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
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 4af1e2b244cb..d5a3009da71a 100644
--- a/kernel/irq/chip.c
+++ b/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.
diff --git a/kernel/irq/debug.h b/kernel/irq/debug.h
index 306cba37e9a5..97a8bfadc88a 100644
--- a/kernel/irq/debug.h
+++ b/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);
diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c
new file mode 100644
index 000000000000..31a9db711906
--- /dev/null
+++ b/kernel/irq/generic-chip.c
@@ -0,0 +1,354 @@
+/*
+ * 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);
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 2c039c9b9383..886e80347b32 100644
--- a/kernel/irq/irqdesc.c
+++ b/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 @@ err:
         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 */
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 07c1611f3899..f7ce0021e1c4 100644
--- a/kernel/irq/manage.c
+++ b/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);
         }
 
         /*
diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h
index 0d91730b6330..f1667833d444 100644
--- a/kernel/irq/settings.h
+++ b/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);