[PATCH] PCI IRQ resource deallocation support [3/3]

[PATCH] PCI IRQ resource deallocation support [3/3]

[Kenji Kaneshige]

This is an ia64 portion of IRQ resource deallocation. It implements
pcibios_disable_device() and acpi_unregister_gsi() for ia64.

    o acpi_unregister_gsi()

        Summary of changes for implementing this interface:

        - Add new function iosapic_unregister_intr() into
          arch/ia64/kernel/iosapic.c. This function frees an interrupt
          vector and related data structures.

        - Add new function free_irq_vector() into
          arch/ia64/kernel/irq_ia64.c. This frees an unused vector.

        - Change assign_irq_vector() to be able to support
          free_irq_vector().

    o pcibios_disable_device()

        This calls acpi_pci_irq_disable() to deallocate IRQ resources.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji-+CUm20s59erQFUHtdCDX3A@public.gmane.org>


---

 linux-2.6.9-rc2-mm1-kanesige/arch/ia64/Kconfig           |    9 +
 linux-2.6.9-rc2-mm1-kanesige/arch/ia64/kernel/acpi.c     |    3 
 linux-2.6.9-rc2-mm1-kanesige/arch/ia64/kernel/iosapic.c  |   82 +++++++++++++--
 linux-2.6.9-rc2-mm1-kanesige/arch/ia64/kernel/irq.c      |    9 +
 linux-2.6.9-rc2-mm1-kanesige/arch/ia64/kernel/irq_ia64.c |   27 ++++
 linux-2.6.9-rc2-mm1-kanesige/arch/ia64/pci/pci.c         |    3 
 linux-2.6.9-rc2-mm1-kanesige/include/asm-ia64/hw_irq.h   |    2 
 linux-2.6.9-rc2-mm1-kanesige/include/asm-ia64/iosapic.h  |    4 
 8 files changed, 124 insertions(+), 15 deletions(-)

diff -puN arch/ia64/Kconfig~IRQ_deallocation_ia64 arch/ia64/Kconfig
--- linux-2.6.9-rc2-mm1/arch/ia64/Kconfig~IRQ_deallocation_ia64	2004-09-21 15:24:28.251867327 +0900
+++ linux-2.6.9-rc2-mm1-kanesige/arch/ia64/Kconfig	2004-09-21 15:24:28.271398701 +0900
@@ -500,6 +500,15 @@ config IA64_PALINFO
 	  To use this option, you have to ensure that the "/proc file system
 	  support" (CONFIG_PROC_FS) is enabled, too.
 
+config IA64_DEALLOCATE_IRQ
+	bool "IRQ resource deallocation support (EXPERIMENTAL)"
+	depends on IOSAPIC && EXPERIMENTAL
+	default n
+	help
+	  Say Y here to experiment with deallocating IRQ resources
+	  dynamically.
+	  Say N if you want to disable IRQ resource deallocation.
+
 source "drivers/firmware/Kconfig"
 
 source "fs/Kconfig.binfmt"
diff -puN arch/ia64/kernel/acpi.c~IRQ_deallocation_ia64 arch/ia64/kernel/acpi.c
--- linux-2.6.9-rc2-mm1/arch/ia64/kernel/acpi.c~IRQ_deallocation_ia64	2004-09-21 15:24:28.259679877 +0900
+++ linux-2.6.9-rc2-mm1-kanesige/arch/ia64/kernel/acpi.c	2004-09-21 15:24:28.272375269 +0900
@@ -524,6 +524,9 @@ EXPORT_SYMBOL(acpi_register_gsi);
 void
 acpi_unregister_gsi (unsigned int irq)
 {
+#ifdef CONFIG_IA64_DEALLOCATE_IRQ
+	iosapic_unregister_intr(irq);
+#endif
 }
 EXPORT_SYMBOL(acpi_unregister_gsi);
 
diff -puN arch/ia64/kernel/iosapic.c~IRQ_deallocation_ia64 arch/ia64/kernel/iosapic.c
--- linux-2.6.9-rc2-mm1/arch/ia64/kernel/iosapic.c~IRQ_deallocation_ia64	2004-09-21 15:24:28.260656445 +0900
+++ linux-2.6.9-rc2-mm1-kanesige/arch/ia64/kernel/iosapic.c	2004-09-21 15:24:28.273351838 +0900
@@ -111,6 +111,7 @@ static struct iosapic_intr_info {
 	unsigned char	dmode	: 3;	/* delivery mode (see iosapic.h) */
 	unsigned char 	polarity: 1;	/* interrupt polarity (see iosapic.h) */
 	unsigned char	trigger	: 1;	/* trigger mode (see iosapic.h) */
+	int		refcnt;		/* reference counter */
 } iosapic_intr_info[IA64_NUM_VECTORS];
 
 static struct iosapic {
@@ -177,7 +178,7 @@ gsi_to_irq (unsigned int gsi)
 static void
 set_rte (unsigned int vector, unsigned int dest, int mask)
 {
-	unsigned long pol, trigger, dmode, flags;
+	unsigned long pol, trigger, dmode;
 	u32 low32, high32;
 	char *addr;
 	int rte_index;
@@ -218,13 +219,9 @@ set_rte (unsigned int vector, unsigned i
 	/* dest contains both id and eid */
 	high32 = (dest << IOSAPIC_DEST_SHIFT);
 
-	spin_lock_irqsave(&iosapic_lock, flags);
-	{
-		iosapic_write(addr, IOSAPIC_RTE_HIGH(rte_index), high32);
-		iosapic_write(addr, IOSAPIC_RTE_LOW(rte_index), low32);
-		iosapic_intr_info[vector].low32 = low32;
-	}
-	spin_unlock_irqrestore(&iosapic_lock, flags);
+	iosapic_write(addr, IOSAPIC_RTE_HIGH(rte_index), high32);
+	iosapic_write(addr, IOSAPIC_RTE_LOW(rte_index), low32);
+	iosapic_intr_info[vector].low32 = low32;
 }
 
 static void
@@ -475,6 +472,7 @@ register_intr (unsigned int gsi, int vec
 	iosapic_intr_info[vector].addr     = iosapic_address;
 	iosapic_intr_info[vector].gsi_base = gsi_base;
 	iosapic_intr_info[vector].trigger  = trigger;
+	iosapic_intr_info[vector].refcnt++;
 
 	if (trigger == IOSAPIC_EDGE)
 		irq_type = &irq_type_iosapic_edge;
@@ -576,6 +574,7 @@ iosapic_register_intr (unsigned int gsi,
 	{
 		vector = gsi_to_vector(gsi);
 		if (vector > 0) {
+			iosapic_intr_info[vector].refcnt++;
 			spin_unlock_irqrestore(&iosapic_lock, flags);
 			return vector;
 		}
@@ -584,6 +583,8 @@ iosapic_register_intr (unsigned int gsi,
 		dest = get_target_cpu(gsi, vector);
 		register_intr(gsi, vector, IOSAPIC_LOWEST_PRIORITY,
 			polarity, trigger);
+
+		set_rte(vector, dest, 1);
 	}
 	spin_unlock_irqrestore(&iosapic_lock, flags);
 
@@ -592,10 +593,73 @@ iosapic_register_intr (unsigned int gsi,
 	       (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
 	       cpu_logical_id(dest), dest, vector);
 
-	set_rte(vector, dest, 1);
 	return vector;
 }
 
+#ifdef CONFIG_IA64_DEALLOCATE_IRQ
+void
+iosapic_unregister_intr (unsigned int irq)
+{
+	unsigned long flags;
+	irq_desc_t *idesc;
+	int rte_index;
+	unsigned int gsi;
+	unsigned long trigger, polarity;
+	ia64_vector vector = irq_to_vector(irq);
+		
+	idesc = irq_descp(irq);
+	spin_lock_irqsave(&idesc->lock, flags);
+	spin_lock(&iosapic_lock);
+	{
+		rte_index = iosapic_intr_info[vector].rte_index;
+		if (rte_index < 0) {
+			spin_unlock(&iosapic_lock);
+			spin_unlock_irqrestore(&idesc->lock, flags);
+			return;		/* not an IOSAPIC interrupt */
+		}
+
+		if (--iosapic_intr_info[vector].refcnt > 0) {
+			spin_unlock(&iosapic_lock);
+			spin_unlock_irqrestore(&idesc->lock, flags);
+			return;
+		}
+
+		/*
+		 * If interrupt handlers still exists on the irq
+		 * associated with the gsi, don't unregister the
+		 * interrupt.
+		 */
+		if (unlikely(idesc->action)) {
+			iosapic_intr_info[vector].refcnt++;
+			spin_unlock_irqrestore(&idesc->lock, flags);
+			printk(KERN_WARNING "Cannot unregister GSI. IRQ %u is still in use.\n", irq);
+			return;
+		}
+
+		/* Clear the interrupt controller descriptor. */
+		idesc->handler = &no_irq_type;
+
+		gsi = iosapic_intr_info[vector].gsi_base + rte_index;
+		trigger  = iosapic_intr_info[vector].trigger;
+		polarity = iosapic_intr_info[vector].polarity;
+
+		/* Clear the interrupt information. */
+		memset(&iosapic_intr_info[vector], 0, sizeof(struct iosapic_intr_info));
+		iosapic_intr_info[vector].rte_index = -1;	/* mark as unused */
+	}
+	spin_unlock(&iosapic_lock);
+	spin_unlock_irqrestore(&idesc->lock, flags);
+
+	/* Free the interrupt vector */
+	free_irq_vector(vector);
+
+	printk(KERN_INFO "GSI %u (%s, %s) -> vector %d unregisterd.\n",
+	       gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
+	       (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
+	       vector);
+}
+#endif /* CONFIG_IA64_DEALLOCATE_IRQ */
+
 /*
  * ACPI calls this when it finds an entry for a platform interrupt.
  * Note that the irq_base and IOSAPIC address must be set in iosapic_init().
diff -puN arch/ia64/kernel/irq.c~IRQ_deallocation_ia64 arch/ia64/kernel/irq.c
--- linux-2.6.9-rc2-mm1/arch/ia64/kernel/irq.c~IRQ_deallocation_ia64	2004-09-21 15:24:28.262609583 +0900
+++ linux-2.6.9-rc2-mm1-kanesige/arch/ia64/kernel/irq.c	2004-09-21 15:24:28.273351838 +0900
@@ -879,8 +879,11 @@ int setup_irq(unsigned int irq, struct i
 	struct irqaction *old, **p;
 	irq_desc_t *desc = irq_descp(irq);
 
-	if (desc->handler == &no_irq_type)
+	spin_lock_irqsave(&desc->lock,flags);
+	if (desc->handler == &no_irq_type) {
+		spin_unlock_irqrestore(&desc->lock,flags);
 		return -ENOSYS;
+	}
 	/*
 	 * Some drivers like serial.c use request_irq() heavily,
 	 * so we have to be careful not to interfere with a
@@ -906,7 +909,6 @@ int setup_irq(unsigned int irq, struct i
 	/*
 	 * The following block of code has to be executed atomically
 	 */
-	spin_lock_irqsave(&desc->lock,flags);
 	p = &desc->action;
 	if ((old = *p) != NULL) {
 		/* Can't share interrupts unless both agree to */
@@ -1040,6 +1042,9 @@ void move_irq(int irq)
 	irq_desc_t *desc = irq_descp(irq);
 	int redir = test_bit(irq, pending_irq_redir);
 
+	if (unlikely(!desc->handler->set_affinity))
+		return;
+
 	if (!cpus_empty(pending_irq_cpumask[irq])) {
 		cpus_and(tmp, pending_irq_cpumask[irq], cpu_online_map);
 		if (unlikely(!cpus_empty(tmp))) {
diff -puN arch/ia64/kernel/irq_ia64.c~IRQ_deallocation_ia64 arch/ia64/kernel/irq_ia64.c
--- linux-2.6.9-rc2-mm1/arch/ia64/kernel/irq_ia64.c~IRQ_deallocation_ia64	2004-09-21 15:24:28.264562720 +0900
+++ linux-2.6.9-rc2-mm1-kanesige/arch/ia64/kernel/irq_ia64.c	2004-09-21 15:24:28.274328407 +0900
@@ -74,15 +74,34 @@ irq_exit (void)
 	preempt_enable_no_resched();
 }
 
+static unsigned long ia64_vector_mask[BITS_TO_LONGS(IA64_NUM_DEVICE_VECTORS)];
+
 int
 assign_irq_vector (int irq)
 {
-	static int next_vector = IA64_FIRST_DEVICE_VECTOR;
-
-	if (next_vector > IA64_LAST_DEVICE_VECTOR)
+	int pos, vector;
+ again:
+	pos = find_first_zero_bit(ia64_vector_mask, IA64_NUM_DEVICE_VECTORS);
+	vector = IA64_FIRST_DEVICE_VECTOR + pos;
+	if (vector > IA64_LAST_DEVICE_VECTOR)
 		/* XXX could look for sharable vectors instead of panic'ing... */
 		panic("assign_irq_vector: out of interrupt vectors!");
-	return next_vector++;
+	if (test_and_set_bit(pos, ia64_vector_mask))
+		goto again;
+	return vector;
+}
+
+void
+free_irq_vector (int vector)
+{
+	int pos;
+
+	if (vector < IA64_FIRST_DEVICE_VECTOR || vector > IA64_LAST_DEVICE_VECTOR)
+		return;
+
+	pos = vector - IA64_FIRST_DEVICE_VECTOR;
+	if (!test_and_clear_bit(pos, ia64_vector_mask))
+		printk(KERN_WARNING "%s: double free!\n", __FUNCTION__);
 }
 
 extern unsigned int do_IRQ(unsigned long irq, struct pt_regs *regs);
diff -puN arch/ia64/pci/pci.c~IRQ_deallocation_ia64 arch/ia64/pci/pci.c
--- linux-2.6.9-rc2-mm1/arch/ia64/pci/pci.c~IRQ_deallocation_ia64	2004-09-21 15:24:28.265539289 +0900
+++ linux-2.6.9-rc2-mm1-kanesige/arch/ia64/pci/pci.c	2004-09-21 15:24:28.274328407 +0900
@@ -451,6 +451,9 @@ pcibios_enable_device (struct pci_dev *d
 void
 pcibios_disable_device (struct pci_dev *dev)
 {
+#ifdef CONFIG_IA64_DEALLOCATE_IRQ
+	acpi_pci_irq_disable(dev);
+#endif /* CONFIG_IA64_DEALLOCATE_IRQ */
 }
 
 void
diff -puN include/asm-ia64/hw_irq.h~IRQ_deallocation_ia64 include/asm-ia64/hw_irq.h
--- linux-2.6.9-rc2-mm1/include/asm-ia64/hw_irq.h~IRQ_deallocation_ia64	2004-09-21 15:24:28.267492426 +0900
+++ linux-2.6.9-rc2-mm1-kanesige/include/asm-ia64/hw_irq.h	2004-09-21 15:24:28.275304975 +0900
@@ -50,6 +50,7 @@ typedef u8 ia64_vector;
  */
 #define IA64_FIRST_DEVICE_VECTOR	0x30
 #define IA64_LAST_DEVICE_VECTOR		0xe7
+#define IA64_NUM_DEVICE_VECTORS		(IA64_LAST_DEVICE_VECTOR - IA64_FIRST_DEVICE_VECTOR + 1)
 
 #define IA64_MCA_RENDEZ_VECTOR		0xe8	/* MCA rendez interrupt */
 #define IA64_PERFMON_VECTOR		0xee	/* performanc monitor interrupt vector */
@@ -83,6 +84,7 @@ extern unsigned long ipi_base_addr;
 extern struct hw_interrupt_type irq_type_ia64_lsapic;	/* CPU-internal interrupt controller */
 
 extern int assign_irq_vector (int irq);	/* allocate a free vector */
+extern void free_irq_vector (int vector);
 extern void ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect);
 extern void register_percpu_irq (ia64_vector vec, struct irqaction *action);
 
diff -puN include/asm-ia64/iosapic.h~IRQ_deallocation_ia64 include/asm-ia64/iosapic.h
--- linux-2.6.9-rc2-mm1/include/asm-ia64/iosapic.h~IRQ_deallocation_ia64	2004-09-21 15:24:28.269445563 +0900
+++ linux-2.6.9-rc2-mm1-kanesige/include/asm-ia64/iosapic.h	2004-09-21 15:24:28.275304975 +0900
@@ -78,6 +78,9 @@ extern int gsi_to_irq (unsigned int gsi)
 extern void iosapic_enable_intr (unsigned int vector);
 extern int iosapic_register_intr (unsigned int gsi, unsigned long polarity,
 				  unsigned long trigger);
+#ifdef CONFIG_IA64_DEALLOCATE_IRQ
+extern void iosapic_unregister_intr (unsigned int irq);
+#endif
 extern void __init iosapic_override_isa_irq (unsigned int isa_irq, unsigned int gsi,
 				      unsigned long polarity,
 				      unsigned long trigger);
@@ -97,6 +100,7 @@ extern void __init map_iosapic_to_node (
 #define iosapic_system_init(pcat_compat)			do { } while (0)
 #define iosapic_init(address,gsi_base)				do { } while (0)
 #define iosapic_register_intr(gsi,polarity,trigger)		(gsi)
+#define iosapic_unregister_intr(irq)				do { } while (0)
 #define iosapic_override_isa_irq(isa_irq,gsi,polarity,trigger)	do { } while (0)
 #define iosapic_register_platform_intr(type,gsi,pmi,eid,id, \
 	polarity,trigger)					(gsi)

_



-------------------------------------------------------
This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170
Project Admins to receive an Apple iPod Mini FREE for your judgement on
who ports your project to Linux PPC the best. Sponsored by IBM.
Deadline: Sept. 24. Go here: http://sf.net/ppc_contest.php