[PATCH 37/42] x86_64: introduce irq_desc_with_new

[Yinghai Lu <yhlu.kernel@gmail.com>]

So could only call that one time

Singed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
---
 arch/x86/kernel/io_apic_64.c |   18 ++++++++++++------
 arch/x86/kernel/irq_64.c     |    4 ++--
 arch/x86/kernel/irqinit_64.c |    3 ++-
 fs/proc/proc_misc.c          |    2 +-
 include/linux/irq.h          |    2 +-
 kernel/irq/chip.c            |    5 +++++
 kernel/irq/handle.c          |   23 +++++------------------
 7 files changed, 28 insertions(+), 29 deletions(-)

diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
index 1466e4b..f8baf58 100644
--- a/arch/x86/kernel/io_apic_64.c
+++ b/arch/x86/kernel/io_apic_64.c
@@ -1117,7 +1117,12 @@ static void ioapic_register_intr(int irq, unsigned long trigger)
 {
 	struct irq_desc *desc;
 
-	desc = irq_desc(irq);
+	/* first time to use this irq_desc */
+	if (irq < 16)
+		desc = irq_desc(irq);
+	else
+		desc = irq_desc_with_new(irq);
+
 	if (trigger)
 		desc->status |= IRQ_LEVEL;
 	else
@@ -3086,8 +3091,6 @@ void __init setup_ioapic_dest(void)
 				continue;
 			irq = pin_2_irq(irq_entry, ioapic, pin);
 
-			desc = irq_desc(irq);
-
 			/* setup_IO_APIC_irqs could fail to get vector for some device
 			 * when you have too many devices, because at that time only boot
 			 * cpu is online.
@@ -3098,13 +3101,16 @@ void __init setup_ioapic_dest(void)
 						  irq_trigger(irq_entry),
 						  irq_polarity(irq_entry));
 #ifdef CONFIG_INTR_REMAP
-			else if (intr_remapping_enabled)
+			else if (intr_remapping_enabled) {
+				desc = irq_desc(irq);
 				set_ir_ioapic_affinity_irq(irq, desc, TARGET_CPUS);
+			}
 #endif
-			else
+			else {
+				desc = irq_desc(irq);
 				set_ioapic_affinity_irq(irq, desc, TARGET_CPUS);
+			}
 		}
-
 	}
 }
 #endif
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 42b2c12..7db6843 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -83,7 +83,7 @@ int show_interrupts(struct seq_file *p, void *v)
 
 	if (i < nr_irqs) {
 		unsigned any_count = 0;
-		struct irq_desc *desc = irq_desc_without_new(i);
+		struct irq_desc *desc = irq_desc(i);
 
 		if (!desc)
 			return 0;
@@ -206,7 +206,7 @@ asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
 	stack_overflow_check(regs);
 #endif
 
-	desc = irq_desc_without_new(irq);
+	desc = irq_desc(irq);
 	if (likely(desc))
 		generic_handle_irq(irq, desc);
 	else {
diff --git a/arch/x86/kernel/irqinit_64.c b/arch/x86/kernel/irqinit_64.c
index 4c55edf..45fca9d 100644
--- a/arch/x86/kernel/irqinit_64.c
+++ b/arch/x86/kernel/irqinit_64.c
@@ -143,7 +143,8 @@ static void __init init_ISA_irqs (void)
 	init_8259A(0);
 
 	for (i = 0; i < 16; i++) {
-		struct irq_desc *desc = irq_desc(i);
+		/* first time call this irq_desc */
+		struct irq_desc *desc = irq_desc_with_new(i);
 
 		desc->status = IRQ_DISABLED;
 		desc->action = NULL;
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index e16c20a..c9ee1f7 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -570,7 +570,7 @@ static int show_stat(struct seq_file *p, void *v)
 	/* sum again ? it could be updated? have another field in irq_desc?*/
 	for (j = 0; j < nr_irqs; j++) {
 		per_irq_sum = 0;
-		desc = irq_desc_without_new(j);
+		desc = irq_desc(j);
 
 		if (desc)
 			for_each_possible_cpu(i) {
diff --git a/include/linux/irq.h b/include/linux/irq.h
index d04182a..0d9578e 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -205,7 +205,7 @@ struct irq_desc {
 } ____cacheline_internodealigned_in_smp;
 
 extern struct irq_desc *irq_desc(unsigned int irq);
-extern struct irq_desc *irq_desc_without_new(unsigned int irq);
+extern struct irq_desc *irq_desc_with_new(unsigned int irq);
 
 #ifndef CONFIG_HAVE_SPARSE_IRQ
 
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index dcac270..bfd02f7 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -36,6 +36,11 @@ void dynamic_irq_init(unsigned int irq)
 
 	/* Ensure we don't have left over values from a previous use of this irq */
 	desc = irq_desc(irq);
+	if (!desc) {
+		/* first time to use this irq_desc */
+		desc = irq_desc_with_new(irq);
+		return;
+	}
 	spin_lock_irqsave(&desc->lock, flags);
 	desc->status = IRQ_DISABLED;
 	desc->chip = &no_irq_chip;
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index e9b54a5..194d815 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -150,7 +150,7 @@ early_param("nr_irq_desc", parse_nr_irq_desc);
 struct irq_desc *irq_descX;
 DEFINE_DYN_ARRAY(irq_descX, sizeof(struct irq_desc), nr_irq_desc, PAGE_SIZE, init_work);
 
-struct irq_desc *irq_desc_without_new(unsigned int irq)
+struct irq_desc *irq_desc(unsigned int irq)
 {
 	struct irq_desc *desc;
 
@@ -168,7 +168,7 @@ struct irq_desc *irq_desc_without_new(unsigned int irq)
 	}
 	return NULL;
 }
-struct irq_desc *irq_desc(unsigned int irq)
+struct irq_desc *irq_desc_with_new(unsigned int irq)
 {
 	struct irq_desc *desc, *desc_pri;
 	int i;
@@ -185,6 +185,7 @@ struct irq_desc *irq_desc(unsigned int irq)
 
 		if (desc->irq == -1U) {
 			desc->irq = irq;
+			printk("found new irq_desc for irq %d\n", desc->irq);
 			return desc;
 		}
 		desc_pri = desc;
@@ -235,21 +236,7 @@ struct irq_desc *irq_desc(unsigned int irq)
 
 	desc->irq = irq;
 	desc_pri->next = desc;
-	{
-		/* double check if some one mess up the list */
-		struct irq_desc *desc;
-		int count = 0;
-
-		desc = &irq_descX[0];
-		while (desc) {
-			printk("1 found irq_desc for irq %d\n", desc->irq);
-			if (desc->next)
-				printk("1 found irq_desc for irq %d and next will be irq %d\n", desc->irq, desc->next->irq);
-			desc = desc->next;
-			count++;
-		}
-		printk("1 all preallocted %d\n", count);
-	}
+	printk("1 found new irq_desc for irq %d and pri will be irq %d\n", desc->irq, desc_pri->irq);
 
 	return desc;
 }
@@ -285,7 +272,7 @@ struct irq_desc *irq_desc(unsigned int irq)
 
 	return NULL;
 }
-struct irq_desc *irq_desc_without_new(unsigned int irq)
+struct irq_desc *irq_desc_with_new(unsigned int irq)
 {
 	return irq_desc(irq);
 }
-- 
1.5.4.5