irq_domain: Move irq_virq_count into NOMAP revmap

This patch replaces the old global setting of irq_virq_count that is only
used by the NOMAP mapping and instead uses a revmap_data property so that
the maximum NOMAP allocation can be set per NOMAP irq_domain.

There is exactly one user of irq_virq_count in-tree right now: PS3.
Also, irq_virq_count is only useful for the NOMAP mapping.  So,
instead of having a single global irq_virq_count values, this change
drops it entirely and added a max_irq argument to irq_domain_add_nomap().
That makes it a property of an individual nomap irq domain instead of
a global system settting.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>

6 files changed, 17 insertions, 31 deletions

diff --git a/arch/powerpc/platforms/cell/axon_msi.c b/arch/powerpc/platforms/cell/axon_msi.c
index db360fc4cf0e..d09f3e8e6867 100644
--- a/arch/powerpc/platforms/cell/axon_msi.c
+++ b/arch/powerpc/platforms/cell/axon_msi.c
@@ -392,7 +392,7 @@ static int axon_msi_probe(struct platform_device *device)
         }
         memset(msic->fifo_virt, 0xff, MSIC_FIFO_SIZE_BYTES);
 
-        msic->irq_domain = irq_domain_add_nomap(dn, &msic_host_ops, msic);
+        msic->irq_domain = irq_domain_add_nomap(dn, 0, &msic_host_ops, msic);
         if (!msic->irq_domain) {
                 printk(KERN_ERR "axon_msi: couldn't allocate irq_domain for %s\n",
                        dn->full_name);
diff --git a/arch/powerpc/platforms/cell/beat_interrupt.c b/arch/powerpc/platforms/cell/beat_interrupt.c
index e5c3a2c6090d..f9a48af335cb 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, &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 a81e5a88fbdf..b4ddaa3fbb29 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, &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/powerpc/platforms/ps3/interrupt.c b/arch/powerpc/platforms/ps3/interrupt.c
index 2a4ff86cc21f..5f3b23220b8e 100644
--- a/arch/powerpc/platforms/ps3/interrupt.c
+++ b/arch/powerpc/platforms/ps3/interrupt.c
@@ -753,9 +753,8 @@ void __init ps3_init_IRQ(void)
         unsigned cpu;
         struct irq_domain *host;
 
-        host = irq_domain_add_nomap(NULL, &ps3_host_ops, NULL);
+        host = irq_domain_add_nomap(NULL, PS3_PLUG_MAX + 1, &ps3_host_ops, NULL);
         irq_set_default_host(host);
-        irq_set_virq_count(PS3_PLUG_MAX + 1);
 
         for_each_possible_cpu(cpu) {
                 struct ps3_private *pd = &per_cpu(ps3_private, cpu);
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index ac17b9b2e7be..c65740d76e66 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -98,6 +98,9 @@ struct irq_domain {
                         unsigned int size;
                         unsigned int *revmap;
                 } linear;
+                struct {
+                        unsigned int max_irq;
+                } nomap;
                 struct radix_tree_root tree;
         } revmap_data;
         const struct irq_domain_ops *ops;
@@ -120,6 +123,7 @@ struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
                                          const struct irq_domain_ops *ops,
                                          void *host_data);
 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,
@@ -128,7 +132,6 @@ struct irq_domain *irq_domain_add_tree(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);
-extern void irq_set_virq_count(unsigned int count);
 
 static inline struct irq_domain *irq_domain_add_legacy_isa(
                                 struct device_node *of_node,
@@ -140,7 +143,6 @@ static inline struct irq_domain *irq_domain_add_legacy_isa(
 }
 extern struct irq_domain *irq_find_host(struct device_node *node);
 extern void irq_set_default_host(struct irq_domain *host);
-extern void irq_set_virq_count(unsigned int count);
 
 
 extern unsigned int irq_create_mapping(struct irq_domain *host,
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index eb05e40f4553..d34413e78628 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -23,7 +23,6 @@ static LIST_HEAD(irq_domain_list);
 static DEFINE_MUTEX(irq_domain_mutex);
 
 static DEFINE_MUTEX(revmap_trees_mutex);
-static unsigned int irq_virq_count = NR_IRQS;
 static struct irq_domain *irq_default_domain;
 
 /**
@@ -184,13 +183,16 @@ struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
 }
 
 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)
+        if (domain) {
+                domain->revmap_data.nomap.max_irq = max_irq ? max_irq : ~0;
                 irq_domain_add(domain);
+        }
         return domain;
 }
 
@@ -262,22 +264,6 @@ void irq_set_default_host(struct irq_domain *domain)
         irq_default_domain = domain;
 }
 
-/**
- * irq_set_virq_count() - Set the maximum number of linux irqs
- * @count: number of linux irqs, capped with NR_IRQS
- *
- * This is mainly for use by platforms like iSeries who want to program
- * the virtual irq number in the controller to avoid the reverse mapping
- */
-void irq_set_virq_count(unsigned int count)
-{
-        pr_debug("irq: Trying to set virq count to %d\n", count);
-
-        BUG_ON(count < NUM_ISA_INTERRUPTS);
-        if (count < NR_IRQS)
-                irq_virq_count = count;
-}
-
 static int irq_setup_virq(struct irq_domain *domain, unsigned int virq,
                             irq_hw_number_t hwirq)
 {
@@ -320,13 +306,12 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain)
                 pr_debug("irq: create_direct virq allocation failed\n");
                 return 0;
         }
-        if (virq >= irq_virq_count) {
+        if (virq >= domain->revmap_data.nomap.max_irq) {
                 pr_err("ERROR: no free irqs available below %i maximum\n",
-                        irq_virq_count);
+                        domain->revmap_data.nomap.max_irq);
                 irq_free_desc(virq);
                 return 0;