Merge tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux

Pull irqdomain refactoring from Grant Likely:
 "This is the long awaited simplification of irqdomain.  It gets rid of
  the different types of irq domains and instead both linear and tree
  mappings can be supported in a single domain.  Doing this removes a
  lot of special case code and makes irq domains simpler to understand
  overall"

* tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux:
  irq: fix checkpatch error
  irqdomain: Include hwirq number in /proc/interrupts
  irqdomain: make irq_linear_revmap() a fast path again
  irqdomain: remove irq_domain_generate_simple()
  irqdomain: Refactor irq_domain_associate_many()
  irqdomain: Beef up debugfs output
  irqdomain: Clean up aftermath of irq_domain refactoring
  irqdomain: Eliminate revmap type
  irqdomain: merge linear and tree reverse mappings.
  irqdomain: Add a name field
  irqdomain: Replace LEGACY mapping with LINEAR
  irqdomain: Relax failure path on setting up mappings

7 files changed, 264 insertions, 473 deletions

diff --git a/arch/powerpc/platforms/cell/beat_interrupt.c b/arch/powerpc/platforms/cell/beat_interrupt.c
index 8c6dc42ecf65..9e5dfbcc00af 100644
--- a/arch/powerpc/platforms/cell/beat_interrupt.c
+++ b/arch/powerpc/platforms/cell/beat_interrupt.c
@@ -239,7 +239,7 @@ void __init beatic_init_IRQ(void)
         ppc_md.get_irq = beatic_get_irq;
 
         /* Allocate an irq host */
-        beatic_host = irq_domain_add_nomap(NULL, 0, &beatic_pic_host_ops, NULL);
+        beatic_host = irq_domain_add_nomap(NULL, ~0, &beatic_pic_host_ops, NULL);
         BUG_ON(beatic_host == NULL);
         irq_set_default_host(beatic_host);
 }
diff --git a/arch/powerpc/platforms/powermac/smp.c b/arch/powerpc/platforms/powermac/smp.c
index 49c9f9501c21..5cbd4d67d5c4 100644
--- a/arch/powerpc/platforms/powermac/smp.c
+++ b/arch/powerpc/platforms/powermac/smp.c
@@ -192,7 +192,7 @@ static int psurge_secondary_ipi_init(void)
 {
         int rc = -ENOMEM;
 
-        psurge_host = irq_domain_add_nomap(NULL, 0, &psurge_host_ops, NULL);
+        psurge_host = irq_domain_add_nomap(NULL, ~0, &psurge_host_ops, NULL);
 
         if (psurge_host)
                 psurge_secondary_virq = irq_create_direct_mapping(psurge_host);
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index b1581527a236..4934890e4db2 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -364,9 +364,7 @@ static void dt_add_ioapic_domain(unsigned int ioapic_num,
                  * and assigned so we can keep the 1:1 mapping which the ioapic
                  * is having.
                  */
-                ret = irq_domain_associate_many(id, 0, 0, NR_IRQS_LEGACY);
-                if (ret)
-                        pr_err("Error mapping legacy IRQs: %d\n", ret);
+                irq_domain_associate_many(id, 0, 0, NR_IRQS_LEGACY);
 
                 if (num > NR_IRQS_LEGACY) {
                         ret = irq_create_strict_mappings(id, NR_IRQS_LEGACY,
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index ba2c708adcff..c983ed18c332 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -73,57 +73,48 @@ struct irq_domain_chip_generic;
 /**
  * struct irq_domain - Hardware interrupt number translation object
  * @link: Element in global irq_domain list.
- * @revmap_type: Method used for reverse mapping hwirq numbers to linux irq. This
- *               will be one of the IRQ_DOMAIN_MAP_* values.
- * @revmap_data: Revmap method specific data.
+ * @name: Name of interrupt domain
  * @ops: pointer to irq_domain methods
  * @host_data: private data pointer for use by owner.  Not touched by irq_domain
  *             core code.
- * @irq_base: Start of irq_desc range assigned to the irq_domain.  The creator
- *            of the irq_domain is responsible for allocating the array of
- *            irq_desc structures.
- * @nr_irq: Number of irqs managed by the irq domain
- * @hwirq_base: Starting number for hwirqs managed by the irq domain
- * @of_node: (optional) Pointer to device tree nodes associated with the
- *           irq_domain.  Used when decoding device tree interrupt specifiers.
+ *
+ * Optional elements
+ * @of_node: Pointer to device tree nodes associated with the irq_domain. Used
+ *           when decoding device tree interrupt specifiers.
+ * @gc: Pointer to a list of generic chips. There is a helper function for
+ *      setting up one or more generic chips for interrupt controllers
+ *      drivers using the generic chip library which uses this pointer.
+ *
+ * Revmap data, used internally by irq_domain
+ * @revmap_direct_max_irq: The largest hwirq that can be set for controllers that
+ *                         support direct mapping
+ * @revmap_size: Size of the linear map table @linear_revmap[]
+ * @revmap_tree: Radix map tree for hwirqs that don't fit in the linear map
+ * @linear_revmap: Linear table of hwirq->virq reverse mappings
  */
 struct irq_domain {
         struct list_head link;
-
-        /* type of reverse mapping_technique */
-        unsigned int revmap_type;
-        union {
-                struct {
-                        unsigned int size;
-                        unsigned int first_irq;
-                        irq_hw_number_t first_hwirq;
-                } legacy;
-                struct {
-                        unsigned int size;
-                        unsigned int *revmap;
-                } linear;
-                struct {
-                        unsigned int max_irq;
-                } nomap;
-                struct radix_tree_root tree;
-        } revmap_data;
+        const char *name;
         const struct irq_domain_ops *ops;
         void *host_data;
-        irq_hw_number_t inval_irq;
 
-        /* Optional device node pointer */
+        /* Optional data */
         struct device_node *of_node;
-        /* Optional pointer to generic interrupt chips */
         struct irq_domain_chip_generic *gc;
-};
 
-#define IRQ_DOMAIN_MAP_LEGACY 0 /* driver allocated fixed range of irqs.
-                                 * ie. legacy 8259, gets irqs 1..15 */
-#define IRQ_DOMAIN_MAP_NOMAP 1 /* no fast reverse mapping */
-#define IRQ_DOMAIN_MAP_LINEAR 2 /* linear map of interrupts */
-#define IRQ_DOMAIN_MAP_TREE 3 /* radix tree */
+        /* reverse map data. The linear map gets appended to the irq_domain */
+        irq_hw_number_t hwirq_max;
+        unsigned int revmap_direct_max_irq;
+        unsigned int revmap_size;
+        struct radix_tree_root revmap_tree;
+        unsigned int linear_revmap[];
+};
 
 #ifdef CONFIG_IRQ_DOMAIN
+struct irq_domain *__irq_domain_add(struct device_node *of_node, int size,
+                                    irq_hw_number_t hwirq_max, int direct_max,
+                                    const struct irq_domain_ops *ops,
+                                    void *host_data);
 struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
                                          unsigned int size,
                                          unsigned int first_irq,
@@ -135,21 +126,30 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
                                          irq_hw_number_t first_hwirq,
                                          const struct irq_domain_ops *ops,
                                          void *host_data);
-struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
+extern struct irq_domain *irq_find_host(struct device_node *node);
+extern void irq_set_default_host(struct irq_domain *host);
+
+/**
+ * irq_domain_add_linear() - Allocate and register a linear revmap irq_domain.
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @size: Number of interrupts in the domain.
+ * @ops: map/unmap domain callbacks
+ * @host_data: Controller private data pointer
+ */
+static inline struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
                                          unsigned int size,
                                          const struct irq_domain_ops *ops,
-                                         void *host_data);
-struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
+                                         void *host_data)
+{
+        return __irq_domain_add(of_node, size, size, 0, ops, host_data);
+}
+static inline struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
                                          unsigned int max_irq,
                                          const struct irq_domain_ops *ops,
-                                         void *host_data);
-struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
-                                         const struct irq_domain_ops *ops,
-                                         void *host_data);
-
-extern struct irq_domain *irq_find_host(struct device_node *node);
-extern void irq_set_default_host(struct irq_domain *host);
-
+                                         void *host_data)
+{
+        return __irq_domain_add(of_node, 0, max_irq, max_irq, ops, host_data);
+}
 static inline struct irq_domain *irq_domain_add_legacy_isa(
                                 struct device_node *of_node,
                                 const struct irq_domain_ops *ops,
@@ -158,21 +158,40 @@ static inline struct irq_domain *irq_domain_add_legacy_isa(
         return irq_domain_add_legacy(of_node, NUM_ISA_INTERRUPTS, 0, 0, ops,
                                      host_data);
 }
+static inline struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
+                                         const struct irq_domain_ops *ops,
+                                         void *host_data)
+{
+        return __irq_domain_add(of_node, 0, ~0, 0, ops, host_data);
+}
 
 extern void irq_domain_remove(struct irq_domain *host);
 
-extern int irq_domain_associate_many(struct irq_domain *domain,
-                                     unsigned int irq_base,
-                                     irq_hw_number_t hwirq_base, int count);
-static inline int irq_domain_associate(struct irq_domain *domain, unsigned int irq,
-                                        irq_hw_number_t hwirq)
-{
-        return irq_domain_associate_many(domain, irq, hwirq, 1);
-}
+extern int irq_domain_associate(struct irq_domain *domain, unsigned int irq,
+                                        irq_hw_number_t hwirq);
+extern void irq_domain_associate_many(struct irq_domain *domain,
+                                      unsigned int irq_base,
+                                      irq_hw_number_t hwirq_base, int count);
 
 extern unsigned int irq_create_mapping(struct irq_domain *host,
                                        irq_hw_number_t hwirq);
 extern void irq_dispose_mapping(unsigned int virq);
+
+/**
+ * irq_linear_revmap() - Find a linux irq from a hw irq number.
+ * @domain: domain owning this hardware interrupt
+ * @hwirq: hardware irq number in that domain space
+ *
+ * This is a fast path alternative to irq_find_mapping() that can be
+ * called directly by irq controller code to save a handful of
+ * instructions. It is always safe to call, but won't find irqs mapped
+ * using the radix tree.
+ */
+static inline unsigned int irq_linear_revmap(struct irq_domain *domain,
+                                             irq_hw_number_t hwirq)
+{
+        return hwirq < domain->revmap_size ? domain->linear_revmap[hwirq] : 0;
+}
 extern unsigned int irq_find_mapping(struct irq_domain *host,
                                      irq_hw_number_t hwirq);
 extern unsigned int irq_create_direct_mapping(struct irq_domain *host);
@@ -186,9 +205,6 @@ static inline int irq_create_identity_mapping(struct irq_domain *host,
         return irq_create_strict_mappings(host, hwirq, hwirq, 1);
 }
 
-extern unsigned int irq_linear_revmap(struct irq_domain *host,
-                                      irq_hw_number_t hwirq);
-
 extern const struct irq_domain_ops irq_domain_simple_ops;
 
 /* stock xlate functions */
@@ -202,14 +218,6 @@ int irq_domain_xlate_onetwocell(struct irq_domain *d, struct device_node *ctrlr,
                         const u32 *intspec, unsigned int intsize,
                         irq_hw_number_t *out_hwirq, unsigned int *out_type);
 
-#if defined(CONFIG_OF_IRQ)
-extern void irq_domain_generate_simple(const struct of_device_id *match,
-                                        u64 phys_base, unsigned int irq_start);
-#else /* CONFIG_OF_IRQ */
-static inline void irq_domain_generate_simple(const struct of_device_id *match,
-                                        u64 phys_base, unsigned int irq_start) { }
-#endif /* !CONFIG_OF_IRQ */
-
 #else /* CONFIG_IRQ_DOMAIN */
 static inline void irq_dispose_mapping(unsigned int virq) { }
 #endif /* !CONFIG_IRQ_DOMAIN */
diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c
index e3544c19bdd2..10e663ab1f4a 100644
--- a/kernel/irq/generic-chip.c
+++ b/kernel/irq/generic-chip.c
@@ -275,10 +275,7 @@ int irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip,
         if (d->gc)
                 return -EBUSY;
 
-        if (d->revmap_type != IRQ_DOMAIN_MAP_LINEAR)
-                return -EINVAL;
-
-        numchips = d->revmap_data.linear.size / irqs_per_chip;
+        numchips = d->revmap_size / irqs_per_chip;
         if (!numchips)
                 return -EINVAL;
 
@@ -310,6 +307,7 @@ int irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip,
                 /* Calc pointer to the next generic chip */
                 tmp += sizeof(*gc) + num_ct * sizeof(struct irq_chip_type);
         }
+        d->name = name;
         return 0;
 }
 EXPORT_SYMBOL_GPL(irq_alloc_domain_generic_chips);
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 1ed8dff17eb9..2d7cd3428365 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -23,9 +23,11 @@ static DEFINE_MUTEX(revmap_trees_mutex);
 static struct irq_domain *irq_default_domain;
 
 /**
- * irq_domain_alloc() - Allocate a new irq_domain data structure
+ * __irq_domain_add() - Allocate a new irq_domain data structure
  * @of_node: optional device-tree node of the interrupt controller
- * @revmap_type: type of reverse mapping to use
+ * @size: Size of linear map; 0 for radix mapping only
+ * @direct_max: Maximum value of direct maps; Use ~0 for no limit; 0 for no
+ *              direct mapping
  * @ops: map/unmap domain callbacks
  * @host_data: Controller private data pointer
  *
@@ -33,41 +35,35 @@ static struct irq_domain *irq_default_domain;
  * register allocated irq_domain with irq_domain_register().  Returns pointer
  * to IRQ domain, or NULL on failure.
  */
-static struct irq_domain *irq_domain_alloc(struct device_node *of_node,
-                                           unsigned int revmap_type,
-                                           const struct irq_domain_ops *ops,
-                                           void *host_data)
+struct irq_domain *__irq_domain_add(struct device_node *of_node, int size,
+                                    irq_hw_number_t hwirq_max, int direct_max,
+                                    const struct irq_domain_ops *ops,
+                                    void *host_data)
 {
         struct irq_domain *domain;
 
-        domain = kzalloc_node(sizeof(*domain), GFP_KERNEL,
-                              of_node_to_nid(of_node));
+        domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size),
+                              GFP_KERNEL, of_node_to_nid(of_node));
         if (WARN_ON(!domain))
                 return NULL;
 
         /* Fill structure */
-        domain->revmap_type = revmap_type;
+        INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL);
         domain->ops = ops;
         domain->host_data = host_data;
         domain->of_node = of_node_get(of_node);
+        domain->hwirq_max = hwirq_max;
+        domain->revmap_size = size;
+        domain->revmap_direct_max_irq = direct_max;
 
-        return domain;
-}
-
-static void irq_domain_free(struct irq_domain *domain)
-{
-        of_node_put(domain->of_node);
-        kfree(domain);
-}
-
-static void irq_domain_add(struct irq_domain *domain)
-{
         mutex_lock(&irq_domain_mutex);
         list_add(&domain->link, &irq_domain_list);
         mutex_unlock(&irq_domain_mutex);
-        pr_debug("Allocated domain of type %d @0x%p\n",
-                 domain->revmap_type, domain);
+
+        pr_debug("Added domain %s\n", domain->name);
+        return domain;
 }
+EXPORT_SYMBOL_GPL(__irq_domain_add);
 
 /**
  * irq_domain_remove() - Remove an irq domain.
@@ -81,29 +77,12 @@ void irq_domain_remove(struct irq_domain *domain)
 {
         mutex_lock(&irq_domain_mutex);
 
-        switch (domain->revmap_type) {
-        case IRQ_DOMAIN_MAP_LEGACY:
-                /*
-                 * Legacy domains don't manage their own irq_desc
-                 * allocations, we expect the caller to handle irq_desc
-                 * freeing on their own.
-                 */
-                break;
-        case IRQ_DOMAIN_MAP_TREE:
-                /*
-                 * radix_tree_delete() takes care of destroying the root
-                 * node when all entries are removed. Shout if there are
-                 * any mappings left.
-                 */
-                WARN_ON(domain->revmap_data.tree.height);
-                break;
-        case IRQ_DOMAIN_MAP_LINEAR:
-                kfree(domain->revmap_data.linear.revmap);
-                domain->revmap_data.linear.size = 0;
-                break;
-        case IRQ_DOMAIN_MAP_NOMAP:
-                break;
-        }
+        /*
+         * radix_tree_delete() takes care of destroying the root
+         * node when all entries are removed. Shout if there are
+         * any mappings left.
+         */
+        WARN_ON(domain->revmap_tree.height);
 
         list_del(&domain->link);
 
@@ -115,44 +94,30 @@ void irq_domain_remove(struct irq_domain *domain)
 
         mutex_unlock(&irq_domain_mutex);
 
-        pr_debug("Removed domain of type %d @0x%p\n",
-                 domain->revmap_type, domain);
+        pr_debug("Removed domain %s\n", domain->name);
 
-        irq_domain_free(domain);
+        of_node_put(domain->of_node);
+        kfree(domain);
 }
 EXPORT_SYMBOL_GPL(irq_domain_remove);
 
-static unsigned int irq_domain_legacy_revmap(struct irq_domain *domain,
-                                             irq_hw_number_t hwirq)
-{
-        irq_hw_number_t first_hwirq = domain->revmap_data.legacy.first_hwirq;
-        int size = domain->revmap_data.legacy.size;
-
-        if (WARN_ON(hwirq < first_hwirq || hwirq >= first_hwirq + size))
-                return 0;
-        return hwirq - first_hwirq + domain->revmap_data.legacy.first_irq;
-}
-
 /**
- * irq_domain_add_simple() - Allocate and register a simple irq_domain.
+ * irq_domain_add_simple() - Register an irq_domain and optionally map a range of irqs
  * @of_node: pointer to interrupt controller's device tree node.
  * @size: total number of irqs in mapping
  * @first_irq: first number of irq block assigned to the domain,
- *      pass zero to assign irqs on-the-fly. This will result in a
- *      linear IRQ domain so it is important to use irq_create_mapping()
- *      for each used IRQ, especially when SPARSE_IRQ is enabled.
+ *      pass zero to assign irqs on-the-fly. If first_irq is non-zero, then
+ *      pre-map all of the irqs in the domain to virqs starting at first_irq.
  * @ops: map/unmap domain callbacks
  * @host_data: Controller private data pointer
  *
- * Allocates a legacy irq_domain if irq_base is positive or a linear
- * domain otherwise. For the legacy domain, IRQ descriptors will also
- * be allocated.
+ * Allocates an irq_domain, and optionally if first_irq is positive then also
+ * allocate irq_descs and map all of the hwirqs to virqs starting at first_irq.
  *
  * This is intended to implement the expected behaviour for most
- * interrupt controllers which is that a linear mapping should
- * normally be used unless the system requires a legacy mapping in
- * order to support supplying interrupt numbers during non-DT
- * registration of devices.
+ * interrupt controllers. If device tree is used, then first_irq will be 0 and
+ * irqs get mapped dynamically on the fly. However, if the controller requires
+ * static virq assignments (non-DT boot) then it will set that up correctly.
  */
 struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
                                          unsigned int size,
@@ -160,33 +125,25 @@ struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
                                          const struct irq_domain_ops *ops,
                                          void *host_data)
 {
-        if (first_irq > 0) {
-                int irq_base;
+        struct irq_domain *domain;
+
+        domain = __irq_domain_add(of_node, size, size, 0, ops, host_data);
+        if (!domain)
+                return NULL;
 
+        if (first_irq > 0) {
                 if (IS_ENABLED(CONFIG_SPARSE_IRQ)) {
-                        /*
-                         * Set the descriptor allocator to search for a
-                         * 1-to-1 mapping, such as irq_alloc_desc_at().
-                         * Use of_node_to_nid() which is defined to
-                         * numa_node_id() on platforms that have no custom
-                         * implementation.
-                         */
-                        irq_base = irq_alloc_descs(first_irq, first_irq, size,
-                                                   of_node_to_nid(of_node));
-                        if (irq_base < 0) {
+                        /* attempt to allocated irq_descs */
+                        int rc = irq_alloc_descs(first_irq, first_irq, size,
+                                                 of_node_to_nid(of_node));
+                        if (rc < 0)
                                 pr_info("Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
                                         first_irq);
-                                irq_base = first_irq;
-                        }
-                } else
-                        irq_base = first_irq;
-
-                return irq_domain_add_legacy(of_node, size, irq_base, 0,
-                                             ops, host_data);
+                }
+                irq_domain_associate_many(domain, first_irq, 0, size);
         }
 
-        /* A linear domain is the default */
-        return irq_domain_add_linear(of_node, size, ops, host_data);
+        return domain;
 }
 EXPORT_SYMBOL_GPL(irq_domain_add_simple);
 
@@ -213,131 +170,19 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
                                          void *host_data)
 {
         struct irq_domain *domain;
-        unsigned int i;
 
-        domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LEGACY, ops, host_data);
+        domain = __irq_domain_add(of_node, first_hwirq + size,
+                                  first_hwirq + size, 0, ops, host_data);
         if (!domain)
                 return NULL;
 
-        domain->revmap_data.legacy.first_irq = first_irq;
-        domain->revmap_data.legacy.first_hwirq = first_hwirq;
-        domain->revmap_data.legacy.size = size;
+        irq_domain_associate_many(domain, first_irq, first_hwirq, size);
 
-        mutex_lock(&irq_domain_mutex);
-        /* Verify that all the irqs are available */
-        for (i = 0; i < size; i++) {
-                int irq = first_irq + i;
-                struct irq_data *irq_data = irq_get_irq_data(irq);
-
-                if (WARN_ON(!irq_data || irq_data->domain)) {
-                        mutex_unlock(&irq_domain_mutex);
-                        irq_domain_free(domain);
-                        return NULL;
-                }
-        }
-
-        /* Claim all of the irqs before registering a legacy domain */
-        for (i = 0; i < size; i++) {
-                struct irq_data *irq_data = irq_get_irq_data(first_irq + i);
-                irq_data->hwirq = first_hwirq + i;
-                irq_data->domain = domain;
-        }
-        mutex_unlock(&irq_domain_mutex);
-
-        for (i = 0; i < size; i++) {
-                int irq = first_irq + i;
-                int hwirq = first_hwirq + i;
-
-                /* IRQ0 gets ignored */
-                if (!irq)
-                        continue;
-
-                /* Legacy flags are left to default at this point,
-                 * one can then use irq_create_mapping() to
-                 * explicitly change them
-                 */
-                if (ops->map)
-                        ops->map(domain, irq, hwirq);
-
-                /* Clear norequest flags */
-                irq_clear_status_flags(irq, IRQ_NOREQUEST);
-        }
-
-        irq_domain_add(domain);
         return domain;
 }
 EXPORT_SYMBOL_GPL(irq_domain_add_legacy);
 
 /**
- * irq_domain_add_linear() - Allocate and register a linear revmap irq_domain.
- * @of_node: pointer to interrupt controller's device tree node.
- * @size: Number of interrupts in the domain.
- * @ops: map/unmap domain callbacks
- * @host_data: Controller private data pointer
- */
-struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
-                                         unsigned int size,
-                                         const struct irq_domain_ops *ops,
-                                         void *host_data)
-{
-        struct irq_domain *domain;
-        unsigned int *revmap;
-
-        revmap = kzalloc_node(sizeof(*revmap) * size, GFP_KERNEL,
-                              of_node_to_nid(of_node));
-        if (WARN_ON(!revmap))
-                return NULL;
-
-        domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LINEAR, ops, host_data);
-        if (!domain) {
-                kfree(revmap);
-                return NULL;
-        }
-        domain->revmap_data.linear.size = size;
-        domain->revmap_data.linear.revmap = revmap;
-        irq_domain_add(domain);
-        return domain;
-}
-EXPORT_SYMBOL_GPL(irq_domain_add_linear);
-
-struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
-                                         unsigned int max_irq,
-                                         const struct irq_domain_ops *ops,
-                                         void *host_data)
-{
-        struct irq_domain *domain = irq_domain_alloc(of_node,
-                                        IRQ_DOMAIN_MAP_NOMAP, ops, host_data);
-        if (domain) {
-                domain->revmap_data.nomap.max_irq = max_irq ? max_irq : ~0;
-                irq_domain_add(domain);
-        }
-        return domain;
-}
-EXPORT_SYMBOL_GPL(irq_domain_add_nomap);
-
-/**
- * irq_domain_add_tree()
- * @of_node: pointer to interrupt controller's device tree node.
- * @ops: map/unmap domain callbacks
- *
- * Note: The radix tree will be allocated later during boot automatically
- * (the reverse mapping will use the slow path until that happens).
- */
-struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
-                                         const struct irq_domain_ops *ops,
-                                         void *host_data)
-{
-        struct irq_domain *domain = irq_domain_alloc(of_node,
-                                        IRQ_DOMAIN_MAP_TREE, ops, host_data);
-        if (domain) {
-                INIT_RADIX_TREE(&domain->revmap_data.tree, GFP_KERNEL);
-                irq_domain_add(domain);
-        }
-        return domain;
-}
-EXPORT_SYMBOL_GPL(irq_domain_add_tree);
-
-/**
  * irq_find_host() - Locates a domain for a given device node
  * @node: device-tree node of the interrupt controller
  */
@@ -385,125 +230,108 @@ void irq_set_default_host(struct irq_domain *domain)
 }
 EXPORT_SYMBOL_GPL(irq_set_default_host);
 
-static void irq_domain_disassociate_many(struct irq_domain *domain,
-                                         unsigned int irq_base, int count)
+static void irq_domain_disassociate(struct irq_domain *domain, unsigned int irq)
 {
-        /*
-         * disassociate in reverse order;
-         * not strictly necessary, but nice for unwinding
-         */
-        while (count--) {
-                int irq = irq_base + count;
-                struct irq_data *irq_data = irq_get_irq_data(irq);
-                irq_hw_number_t hwirq;
+        struct irq_data *irq_data = irq_get_irq_data(irq);
+        irq_hw_number_t hwirq;
 
-                if (WARN_ON(!irq_data || irq_data->domain != domain))
-                        continue;
+        if (WARN(!irq_data || irq_data->domain != domain,
+                 "virq%i doesn't exist; cannot disassociate\n", irq))
+                return;
 
-                hwirq = irq_data->hwirq;
-                irq_set_status_flags(irq, IRQ_NOREQUEST);
+        hwirq = irq_data->hwirq;
+        irq_set_status_flags(irq, IRQ_NOREQUEST);
 
-                /* remove chip and handler */
-                irq_set_chip_and_handler(irq, NULL, NULL);
+        /* remove chip and handler */
+        irq_set_chip_and_handler(irq, NULL, NULL);
 
-                /* Make sure it's completed */
-                synchronize_irq(irq);
+        /* Make sure it's completed */
+        synchronize_irq(irq);
 
-                /* Tell the PIC about it */
-                if (domain->ops->unmap)
-                        domain->ops->unmap(domain, irq);
-                smp_mb();
+        /* Tell the PIC about it */
+        if (domain->ops->unmap)
+                domain->ops->unmap(domain, irq);
+        smp_mb();
 
-                irq_data->domain = NULL;
-                irq_data->hwirq = 0;
+        irq_data->domain = NULL;
+        irq_data->hwirq = 0;
 
-                /* Clear reverse map */
-                switch(domain->revmap_type) {
-                case IRQ_DOMAIN_MAP_LINEAR:
-                        if (hwirq < domain->revmap_data.linear.size)
-                                domain->revmap_data.linear.revmap[hwirq] = 0;
-                        break;
-                case IRQ_DOMAIN_MAP_TREE:
-                        mutex_lock(&revmap_trees_mutex);
-                        radix_tree_delete(&domain->revmap_data.tree, hwirq);
-                        mutex_unlock(&revmap_trees_mutex);
-                        break;
-                }
+        /* Clear reverse map for this hwirq */
+        if (hwirq < domain->revmap_size) {
+                domain->linear_revmap[hwirq] = 0;
+        } else {
+                mutex_lock(&revmap_trees_mutex);
+                radix_tree_delete(&domain->revmap_tree, hwirq);
+                mutex_unlock(&revmap_trees_mutex);
         }
 }
 
-int irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base,
-                              irq_hw_number_t hwirq_base, int count)
+int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
+                         irq_hw_number_t hwirq)
 {
-        unsigned int virq = irq_base;
-        irq_hw_number_t hwirq = hwirq_base;
-        int i, ret;
+        struct irq_data *irq_data = irq_get_irq_data(virq);
+        int ret;
 
-        pr_debug("%s(%s, irqbase=%i, hwbase=%i, count=%i)\n", __func__,
-                of_node_full_name(domain->of_node), irq_base, (int)hwirq_base, count);
+        if (WARN(hwirq >= domain->hwirq_max,
+                 "error: hwirq 0x%x is too large for %s\n", (int)hwirq, domain->name))
+                return -EINVAL;
+        if (WARN(!irq_data, "error: virq%i is not allocated", virq))
+                return -EINVAL;
+        if (WARN(irq_data->domain, "error: virq%i is already associated", virq))
+                return -EINVAL;
 
-        for (i = 0; i < count; i++) {
-                struct irq_data *irq_data = irq_get_irq_data(virq + i);
-
-                if (WARN(!irq_data, "error: irq_desc not allocated; "
-                         "irq=%i hwirq=0x%x\n", virq + i, (int)hwirq + i))
-                        return -EINVAL;
-                if (WARN(irq_data->domain, "error: irq_desc already associated; "
-                         "irq=%i hwirq=0x%x\n", virq + i, (int)hwirq + i))
-                        return -EINVAL;
-        };
-
-        for (i = 0; i < count; i++, virq++, hwirq++) {
-                struct irq_data *irq_data = irq_get_irq_data(virq);
-
-                irq_data->hwirq = hwirq;
-                irq_data->domain = domain;
-                if (domain->ops->map) {
-                        ret = domain->ops->map(domain, virq, hwirq);
-                        if (ret != 0) {
-                                /*
-                                 * If map() returns -EPERM, this interrupt is protected
-                                 * by the firmware or some other service and shall not
-                                 * be mapped.
-                                 *
-                                 * Since on some platforms we blindly try to map everything
-                                 * we end up with a log full of backtraces.
-                                 *
-                                 * So instead, we silently fail on -EPERM, it is the
-                                 * responsibility of the PIC driver to display a relevant
-                                 * message if needed.
-                                 */
-                                if (ret != -EPERM) {
-                                        pr_err("irq-%i==>hwirq-0x%lx mapping failed: %d\n",
-                                               virq, hwirq, ret);
-                                        WARN_ON(1);
-                                }
-                                irq_data->domain = NULL;
-                                irq_data->hwirq = 0;
-                                goto err_unmap;
+        mutex_lock(&irq_domain_mutex);
+        irq_data->hwirq = hwirq;
+        irq_data->domain = domain;
+        if (domain->ops->map) {
+                ret = domain->ops->map(domain, virq, hwirq);
+                if (ret != 0) {
+                        /*
+                         * If map() returns -EPERM, this interrupt is protected
+                         * by the firmware or some other service and shall not
+                         * be mapped. Don't bother telling the user about it.
+                         */
+                        if (ret != -EPERM) {
+                                pr_info("%s didn't like hwirq-0x%lx to VIRQ%i mapping (rc=%d)\n",
+                                       domain->name, hwirq, virq, ret);
                         }
+                        irq_data->domain = NULL;
+                        irq_data->hwirq = 0;
+                        mutex_unlock(&irq_domain_mutex);
+                        return ret;
                 }
 
-                switch (domain->revmap_type) {
-                case IRQ_DOMAIN_MAP_LINEAR:
-                        if (hwirq < domain->revmap_data.linear.size)
-                                domain->revmap_data.linear.revmap[hwirq] = virq;
-                        break;
-                case IRQ_DOMAIN_MAP_TREE:
-                        mutex_lock(&revmap_trees_mutex);
-                        radix_tree_insert(&domain->revmap_data.tree, hwirq, irq_data);
-                        mutex_unlock(&revmap_trees_mutex);
-                        break;
-                }
+                /* If not already assigned, give the domain the chip's name */
+                if (!domain->name && irq_data->chip)
+                        domain->name = irq_data->chip->name;
+        }
 
-                irq_clear_status_flags(virq, IRQ_NOREQUEST);
+        if (hwirq < domain->revmap_size) {
+                domain->linear_revmap[hwirq] = virq;
+        } else {
+                mutex_lock(&revmap_trees_mutex);
+                radix_tree_insert(&domain->revmap_tree, hwirq, irq_data);
+                mutex_unlock(&revmap_trees_mutex);
         }
+        mutex_unlock(&irq_domain_mutex);
+
+        irq_clear_status_flags(virq, IRQ_NOREQUEST);
 
         return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_associate);
 
- err_unmap:
-        irq_domain_disassociate_many(domain, irq_base, i);
-        return -EINVAL;
+void irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base,
+                               irq_hw_number_t hwirq_base, int count)
+{
+        int i;
+
+        pr_debug("%s(%s, irqbase=%i, hwbase=%i, count=%i)\n", __func__,
+                of_node_full_name(domain->of_node), irq_base, (int)hwirq_base, count);
+
+        for (i = 0; i < count; i++) {
+                irq_domain_associate(domain, irq_base + i, hwirq_base + i);
+        }
 }
 EXPORT_SYMBOL_GPL(irq_domain_associate_many);
 
@@ -513,7 +341,9 @@ EXPORT_SYMBOL_GPL(irq_domain_associate_many);
  *
  * This routine is used for irq controllers which can choose the hardware
  * interrupt numbers they generate. In such a case it's simplest to use
- * the linux irq as the hardware interrupt number.
+ * the linux irq as the hardware interrupt number. It still uses the linear
+ * or radix tree to store the mapping, but the irq controller can optimize
+ * the revmap path by using the hwirq directly.
  */
 unsigned int irq_create_direct_mapping(struct irq_domain *domain)
 {
@@ -522,17 +352,14 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain)
         if (domain == NULL)
                 domain = irq_default_domain;
 
-        if (WARN_ON(!domain || domain->revmap_type != IRQ_DOMAIN_MAP_NOMAP))
-                return 0;
-
         virq = irq_alloc_desc_from(1, of_node_to_nid(domain->of_node));
         if (!virq) {
                 pr_debug("create_direct virq allocation failed\n");
                 return 0;
         }
-        if (virq >= domain->revmap_data.nomap.max_irq) {
+        if (virq >= domain->revmap_direct_max_irq) {
                 pr_err("ERROR: no free irqs available below %i maximum\n",
-                        domain->revmap_data.nomap.max_irq);
+                        domain->revmap_direct_max_irq);
                 irq_free_desc(virq);
                 return 0;
         }
@@ -569,9 +396,7 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
         if (domain == NULL)
                 domain = irq_default_domain;
         if (domain == NULL) {
-                pr_warning("irq_create_mapping called for"
-                           " NULL domain, hwirq=%lx\n", hwirq);
-                WARN_ON(1);
+                WARN(1, "%s(, %lx) called with NULL domain\n", __func__, hwirq);
                 return 0;
         }
         pr_debug("-> using domain @%p\n", domain);
@@ -583,10 +408,6 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
                 return virq;
         }
 
-        /* Get a virtual interrupt number */
-        if (domain->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
-                return irq_domain_legacy_revmap(domain, hwirq);
-
         /* Allocate a virtual interrupt number */
         hint = hwirq % nr_irqs;
         if (hint == 0)
@@ -639,12 +460,7 @@ int irq_create_strict_mappings(struct irq_domain *domain, unsigned int irq_base,
         if (unlikely(ret < 0))
                 return ret;
 
-        ret = irq_domain_associate_many(domain, irq_base, hwirq_base, count);
-        if (unlikely(ret < 0)) {
-                irq_free_descs(irq_base, count);
-                return ret;
-        }
-
+        irq_domain_associate_many(domain, irq_base, hwirq_base, count);
         return 0;
 }
 EXPORT_SYMBOL_GPL(irq_create_strict_mappings);
@@ -671,8 +487,8 @@ unsigned int irq_create_of_mapping(struct device_node *controller,
                 if (intsize > 0)
                         return intspec[0];
 #endif
-                pr_warning("no irq domain found for %s !\n",
-                           of_node_full_name(controller));
+                pr_warn("no irq domain found for %s !\n",
+                        of_node_full_name(controller));
                 return 0;
         }
 
@@ -714,11 +530,7 @@ void irq_dispose_mapping(unsigned int virq)
         if (WARN_ON(domain == NULL))
                 return;
 
-        /* Never unmap legacy interrupts */
-        if (domain->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
-                return;
-
-        irq_domain_disassociate_many(domain, virq, 1);
+        irq_domain_disassociate(domain, virq);
         irq_free_desc(virq);
 }
 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
@@ -739,63 +551,51 @@ unsigned int irq_find_mapping(struct irq_domain *domain,
         if (domain == NULL)
                 return 0;
 
-        switch (domain->revmap_type) {
-        case IRQ_DOMAIN_MAP_LEGACY:
-                return irq_domain_legacy_revmap(domain, hwirq);
-        case IRQ_DOMAIN_MAP_LINEAR:
-                return irq_linear_revmap(domain, hwirq);
-        case IRQ_DOMAIN_MAP_TREE:
-                rcu_read_lock();
-                data = radix_tree_lookup(&domain->revmap_data.tree, hwirq);
-                rcu_read_unlock();
-                if (data)
-                        return data->irq;
-                break;
-        case IRQ_DOMAIN_MAP_NOMAP:
+        if (hwirq < domain->revmap_direct_max_irq) {
                 data = irq_get_irq_data(hwirq);
                 if (data && (data->domain == domain) && (data->hwirq == hwirq))
                         return hwirq;
-                break;
         }
 
-        return 0;
-}
-EXPORT_SYMBOL_GPL(irq_find_mapping);
+        /* Check if the hwirq is in the linear revmap. */
+        if (hwirq < domain->revmap_size)
+                return domain->linear_revmap[hwirq];
 
-/**
- * irq_linear_revmap() - Find a linux irq from a hw irq number.
- * @domain: domain owning this hardware interrupt
- * @hwirq: hardware irq number in that domain space
- *
- * This is a fast path that can be called directly by irq controller code to
- * save a handful of instructions.
- */
-unsigned int irq_linear_revmap(struct irq_domain *domain,
-                               irq_hw_number_t hwirq)
-{
-        BUG_ON(domain->revmap_type != IRQ_DOMAIN_MAP_LINEAR);
-
-        /* Check revmap bounds; complain if exceeded */
-        if (WARN_ON(hwirq >= domain->revmap_data.linear.size))
-                return 0;
-
-        return domain->revmap_data.linear.revmap[hwirq];
+        rcu_read_lock();
+        data = radix_tree_lookup(&domain->revmap_tree, hwirq);
+        rcu_read_unlock();
+        return data ? data->irq : 0;
 }
-EXPORT_SYMBOL_GPL(irq_linear_revmap);
+EXPORT_SYMBOL_GPL(irq_find_mapping);
 
 #ifdef CONFIG_IRQ_DOMAIN_DEBUG
 static int virq_debug_show(struct seq_file *m, void *private)
 {
         unsigned long flags;
         struct irq_desc *desc;
-        const char *p;
-        static const char none[] = "none";
-        void *data;
+        struct irq_domain *domain;
+        struct radix_tree_iter iter;
+        void *data, **slot;
         int i;
 
-        seq_printf(m, "%-5s  %-7s  %-15s  %-*s  %s\n", "irq", "hwirq",
+        seq_printf(m, " %-16s  %-6s  %-10s  %-10s  %s\n",
+                   "name", "mapped", "linear-max", "direct-max", "devtree-node");
+        mutex_lock(&irq_domain_mutex);
+        list_for_each_entry(domain, &irq_domain_list, link) {
+                int count = 0;
+                radix_tree_for_each_slot(slot, &domain->revmap_tree, &iter, 0)
+                        count++;
+                seq_printf(m, "%c%-16s  %6u  %10u  %10u  %s\n",
+                           domain == irq_default_domain ? '*' : ' ', domain->name,
+                           domain->revmap_size + count, domain->revmap_size,
+                           domain->revmap_direct_max_irq,
+                           domain->of_node ? of_node_full_name(domain->of_node) : "");
+        }
+        mutex_unlock(&irq_domain_mutex);
+
+        seq_printf(m, "%-5s  %-7s  %-15s  %-*s  %6s  %-14s  %s\n", "irq", "hwirq",
                       "chip name", (int)(2 * sizeof(void *) + 2), "chip data",
-                      "domain name");
+                      "active", "type", "domain");
 
         for (i = 1; i < nr_irqs; i++) {
                 desc = irq_to_desc(i);
@@ -803,28 +603,28 @@ static int virq_debug_show(struct seq_file *m, void *private)
                         continue;
 
                 raw_spin_lock_irqsave(&desc->lock, flags);
+                domain = desc->irq_data.domain;
 
-                if (desc->action && desc->action->handler) {
+                if (domain) {
                         struct irq_chip *chip;
+                        int hwirq = desc->irq_data.hwirq;
+                        bool direct;
 
                         seq_printf(m, "%5d  ", i);
-                        seq_printf(m, "0x%05lx  ", desc->irq_data.hwirq);
+                        seq_printf(m, "0x%05x  ", hwirq);
 
                         chip = irq_desc_get_chip(desc);
-                        if (chip && chip->name)
-                                p = chip->name;
-                        else
-                                p = none;
-                        seq_printf(m, "%-15s  ", p);
+                        seq_printf(m, "%-15s  ", (chip && chip->name) ? chip->name : "none");
 
                         data = irq_desc_get_chip_data(desc);
                         seq_printf(m, data ? "0x%p  " : "  %p  ", data);
 
-                        if (desc->irq_data.domain)
-                                p = of_node_full_name(desc->irq_data.domain->of_node);
-                        else
-                                p = none;
-                        seq_printf(m, "%s\n", p);
+                        seq_printf(m, "   %c    ", (desc->action && desc->action->handler) ? '*' : ' ');
+                        direct = (i == hwirq) && (i < domain->revmap_direct_max_irq);
+                        seq_printf(m, "%6s%-8s  ",
+                                   (hwirq < domain->revmap_size) ? "LINEAR" : "RADIX",
+                                   direct ? "(DIRECT)" : "");
+                        seq_printf(m, "%s\n", desc->irq_data.domain->name);
                 }
 
                 raw_spin_unlock_irqrestore(&desc->lock, flags);
@@ -921,18 +721,3 @@ const struct irq_domain_ops irq_domain_simple_ops = {
         .xlate = irq_domain_xlate_onetwocell,
 };
 EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
-
-#ifdef CONFIG_OF_IRQ
-void irq_domain_generate_simple(const struct of_device_id *match,
-                                u64 phys_base, unsigned int irq_start)
-{
-        struct device_node *node;
-        pr_debug("looking for phys_base=%llx, irq_start=%i\n",
-                (unsigned long long) phys_base, (int) irq_start);
-        node = of_find_matching_node_by_address(NULL, match, phys_base);
-        if (node)
-                irq_domain_add_legacy(node, 32, irq_start, 0,
-                                      &irq_domain_simple_ops, NULL);
-}
-EXPORT_SYMBOL_GPL(irq_domain_generate_simple);
-#endif
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 19ed5c425c3b..36f6ee181b0c 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -462,6 +462,8 @@ int show_interrupts(struct seq_file *p, void *v)
         } else {
                 seq_printf(p, " %8s", "None");
         }
+        if (desc->irq_data.domain)
+                seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq);
 #ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
         seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
 #endif