Add mapping table between irq and vector

Add mapping tables between irqs and vectors, and its management code. This is necessary for supporting multiple vector domain because 1:1 mapping between irq and vector will be changed to n:1.

The irq = vector relationship between irqs and vectors is explicitly remained for percpu interrupts, platform interrupts, isa IRQs and vectors assigned using assign_irq_vector() because some programs might depend on it.

---
 arch/ia64/kernel/iosapic.c  |   12 +--
 arch/ia64/kernel/irq.c      |    2
 arch/ia64/kernel/irq_ia64.c |  162 ++++++++++++++++++++++++++++++++++----------
 arch/ia64/kernel/smpboot.c  |    4 +
 include/asm-ia64/hw_irq.h   |   13 ++-
 5 files changed, 150 insertions(+), 43 deletions(-)

Index: linux-2.6.21/arch/ia64/kernel/irq_ia64.c
=================================--- linux-2.6.21.orig/arch/ia64/kernel/irq_ia64.c 2007-04-26 12:08:32.000000000 +0900
+++ linux-2.6.21/arch/ia64/kernel/irq_ia64.c 2007-05-08 12:10:57.000000000 +0900
@@ -46,6 +46,9 @@

#define IRQ_DEBUG 0

+#define IRQ_VECTOR_UNASSIGNED (0)
+#define VECTOR_IRQ_UNASSIGNED (-1)
+
/* These can be overridden in platform_irq_init */ int ia64_first_device_vector = IA64_DEF_FIRST_DEVICE_VECTOR; int ia64_last_device_vector = IA64_DEF_LAST_DEVICE_VECTOR;
@@ -64,46 +67,127 @@
};
EXPORT_SYMBOL(isa_irq_to_vector_map);

-static unsigned long ia64_vector_mask[BITS_TO_LONGS(IA64_MAX_DEVICE_VECTORS)]; +DEFINE_SPINLOCK(vector_lock);
+
+struct irq_cfg irq_cfg[NR_IRQS] __read_mostly = {
+ [0 ... NR_IRQS - 1] = { .vector = IRQ_VECTOR_UNASSIGNED }
+};
+
+DEFINE_PER_CPU(int[IA64_NUM_VECTORS], vector_irq) = {
+ [0 ... IA64_NUM_VECTORS - 1] = VECTOR_IRQ_UNASSIGNED
+};
+
+static inline int find_unassigned_irq(void)
+{
+ int irq;
+
+ for (irq = IA64_FIRST_DEVICE_VECTOR; irq < NR_IRQS; irq++)
+ if (irq_cfg[irq].vector = IRQ_VECTOR_UNASSIGNED)
+ return irq;
+ return -ENOSPC;
+}
+
+static inline int find_unassigned_vector(void)
+{
+ int vector;
+
+ for (vector = IA64_FIRST_DEVICE_VECTOR;
+ vector <= IA64_LAST_DEVICE_VECTOR; vector++)
+ if (__get_cpu_var(vector_irq[vector]) = VECTOR_IRQ_UNASSIGNED)
+ return vector;
+ return -ENOSPC;
+}
+
+static int __bind_irq_vector(int irq, int vector)
+{
+ int cpu;
+
+ if (irq_to_vector(irq) = vector)
+ return 0;
+ if (irq_to_vector(irq) != IRQ_VECTOR_UNASSIGNED)
+ return -EBUSY;
+ for_each_online_cpu(cpu)
+ per_cpu(vector_irq, cpu)[vector] = irq;
+ irq_cfg[irq].vector = vector;
+ return 0;
+}
+
+int bind_irq_vector(int irq, int vector)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&vector_lock, flags);
+ ret = __bind_irq_vector(irq, vector);
+ spin_unlock_irqrestore(&vector_lock, flags);
+ return ret;
+}
+
+static void clear_irq_vector(int irq)
+{
+ unsigned long flags;
+ int vector, cpu;
+
+ spin_lock_irqsave(&vector_lock, flags);
+ BUG_ON((unsigned)irq >= NR_IRQS);
+ BUG_ON(irq_cfg[irq].vector = IRQ_VECTOR_UNASSIGNED);
+ vector = irq_cfg[irq].vector;
+ for_each_online_cpu(cpu)
+ per_cpu(vector_irq, cpu)[vector] = VECTOR_IRQ_UNASSIGNED;
+ irq_cfg[irq].vector = IRQ_VECTOR_UNASSIGNED;
+ spin_unlock_irqrestore(&vector_lock, flags);
+}

int
assign_irq_vector (int irq)
{
- 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)
- return -ENOSPC;
- if (test_and_set_bit(pos, ia64_vector_mask))
- goto again;
+ unsigned long flags;
+ int vector;
+
+ spin_lock_irqsave(&vector_lock, flags);
+ vector = find_unassigned_vector();
+ if (vector < 0)
+ goto out;
+ BUG_ON(__bind_irq_vector(vector, vector));
+ spin_unlock_irqrestore(&vector_lock, flags);
+ out:
return vector;
}

void
free_irq_vector (int vector)
{
- int pos;
-

-	if (vector < IA64_FIRST_DEVICE_VECTOR || vector > IA64_LAST_DEVICE_VECTOR)
+	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__);
+ clear_irq_vector(vector);
}

int
reserve_irq_vector (int vector)
{
- int pos;
-
if (vector < IA64_FIRST_DEVICE_VECTOR ||
vector > IA64_LAST_DEVICE_VECTOR)
return -EINVAL;
+ return !!bind_irq_vector(vector, vector);
+}
+
+/*
+ * Initialize vector_irq on a new cpu. This function must be called
+ * with vector_lock held.
+ */
+void __setup_vector_irq(int cpu)
+{
+ int irq, vector;

- pos = vector - IA64_FIRST_DEVICE_VECTOR;
- return test_and_set_bit(pos, ia64_vector_mask);
+ /* Clear vector_irq */
+ for (vector = 0; vector < IA64_NUM_VECTORS; ++vector)
+ per_cpu(vector_irq, cpu)[vector] = VECTOR_IRQ_UNASSIGNED;
+ /* Mark the inuse vectors */
+ for (irq = 0; irq < NR_IRQS; ++irq) {
+ if ((vector = irq_to_vector(irq)) != IRQ_VECTOR_UNASSIGNED)
+ per_cpu(vector_irq, cpu)[vector] = irq;
+ }
}

/*
@@ -111,18 +195,29 @@
*/
int create_irq(void)
{
- int vector = assign_irq_vector(AUTO_ASSIGN);
-
- if (vector >= 0)
- dynamic_irq_init(vector);
+ unsigned long flags;
+ int irq, vector;

- return vector;
+ irq = -ENOSPC;
+ spin_lock_irqsave(&vector_lock, flags);
+ vector = find_unassigned_vector();
+ if (vector < 0)
+ goto out;
+ irq = find_unassigned_irq();
+ if (irq < 0)
+ goto out;
+ BUG_ON(__bind_irq_vector(irq, vector));
+ out:
+ spin_unlock_irqrestore(&vector_lock, flags);
+ if (irq >= 0)
+ dynamic_irq_init(irq);
+ return irq;
}

void destroy_irq(unsigned int irq)
{
dynamic_irq_cleanup(irq);
- free_irq_vector(irq);
+ clear_irq_vector(irq);
}

#ifdef CONFIG_SMP
@@ -286,14 +381,13 @@
irq_desc_t *desc;
unsigned int irq;

- for (irq = 0; irq < NR_IRQS; ++irq)
- if (irq_to_vector(irq) = vec) {
- desc = irq_desc + irq;
- desc->status |= IRQ_PER_CPU;
- desc->chip = &irq_type_ia64_lsapic;
- if (action)
- setup_irq(irq, action);
- }
+ irq = vec;
+ BUG_ON(bind_irq_vector(irq, vec));
+ desc = irq_desc + irq;
+ desc->status |= IRQ_PER_CPU;
+ desc->chip = &irq_type_ia64_lsapic;
+ if (action)
+ setup_irq(irq, action);
}

void __init
Index: linux-2.6.21/arch/ia64/kernel/iosapic.c
=================================--- linux-2.6.21.orig/arch/ia64/kernel/iosapic.c 2007-05-08 12:10:09.000000000 +0900
+++ linux-2.6.21/arch/ia64/kernel/iosapic.c 2007-05-08 12:10:57.000000000 +0900
@@ -893,8 +893,8 @@

switch (int_type) {
case ACPI_INTERRUPT_PMI:
- vector = iosapic_vector;
- irq = vector; /* FIXME */
+ irq = vector = iosapic_vector;
+ bind_irq_vector(irq, vector);
/*
* since PMI vector is alloc'd by FW(ACPI) not by kernel,
* we need to make sure the vector is available
@@ -910,8 +910,8 @@
delivery = IOSAPIC_INIT;
break;
case ACPI_INTERRUPT_CPEI:
- vector = IA64_CPE_VECTOR;
- irq = vector; /* FIXME */
+ irq = vector = IA64_CPE_VECTOR;
+ BUG_ON(bind_irq_vector(irq, vector));
delivery = IOSAPIC_LOWEST_PRIORITY;
mask = 1;
break;
@@ -946,8 +946,8 @@
int vector, irq;
unsigned int dest = cpu_physical_id(smp_processor_id());

- vector = isa_irq_to_vector(isa_irq);
- irq = vector; /* FIXME */
+ irq = vector = isa_irq_to_vector(isa_irq);
+ BUG_ON(bind_irq_vector(irq, vector));
register_intr(gsi, irq, IOSAPIC_LOWEST_PRIORITY, polarity, trigger);

DBG("ISA: IRQ %u -> GSI %u (%s,%s) -> CPU %d (0x%04x) vector %d\n",
Index: linux-2.6.21/arch/ia64/kernel/irq.c
=================================--- linux-2.6.21.orig/arch/ia64/kernel/irq.c 2007-04-26 12:08:32.000000000 +0900
+++ linux-2.6.21/arch/ia64/kernel/irq.c 2007-05-08 12:10:57.000000000 +0900
@@ -35,7 +35,7 @@
#ifdef CONFIG_IA64_GENERIC
unsigned int __ia64_local_vector_to_irq (ia64_vector vec)
{
- return (unsigned int) vec;
+ return __get_cpu_var(vector_irq)[vec];
}
#endif

Index: linux-2.6.21/arch/ia64/kernel/smpboot.c
=================================--- linux-2.6.21.orig/arch/ia64/kernel/smpboot.c 2007-04-26 12:08:32.000000000 +0900
+++ linux-2.6.21/arch/ia64/kernel/smpboot.c 2007-05-08 12:10:57.000000000 +0900
@@ -396,9 +396,13 @@
fix_b0_for_bsp();

lock_ipi_calllock();
+ spin_lock(&vector_lock);
+ /* Setup the per cpu irq handling data structures */
+ __setup_vector_irq(cpuid);
cpu_set(cpuid, cpu_online_map);
unlock_ipi_calllock();
per_cpu(cpu_state, cpuid) = CPU_ONLINE;
+ spin_unlock(&vector_lock);

smp_setup_percpu_timer();

Index: linux-2.6.21/include/asm-ia64/hw_irq.h
=================================--- linux-2.6.21.orig/include/asm-ia64/hw_irq.h 2007-04-26 12:08:32.000000000 +0900
+++ linux-2.6.21/include/asm-ia64/hw_irq.h 2007-05-08 12:10:57.000000000 +0900
@@ -89,11 +89,20 @@
extern __u8 isa_irq_to_vector_map[16];
#define isa_irq_to_vector(x) isa_irq_to_vector_map[(x)]

+struct irq_cfg {
+ ia64_vector vector;
+};
+extern spinlock_t vector_lock;
+extern struct irq_cfg irq_cfg[NR_IRQS]; +DECLARE_PER_CPU(int[IA64_NUM_VECTORS], vector_irq); +
extern struct hw_interrupt_type irq_type_ia64_lsapic; /* CPU-internal interrupt controller */

+extern int bind_irq_vector(int irq, int vector);
extern int assign_irq_vector (int irq); /* allocate a free vector */
extern void free_irq_vector (int vector);
extern int reserve_irq_vector (int vector);
+extern void __setup_vector_irq(int cpu);
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);

@@ -112,7 +121,7 @@
static inline unsigned int
__ia64_local_vector_to_irq (ia64_vector vec)
{
- return (unsigned int) vec;
+ return __get_cpu_var(vector_irq)[vec];
}
#endif

@@ -130,7 +139,7 @@
static inline ia64_vector
irq_to_vector (int irq)
{
- return (ia64_vector) irq;
+ return irq_cfg[irq].vector;
}

/*

I found why my machine sometimes crashes during boot with the vector domain patch applied. The problem is a spurious interrupt that causes a wild pointer reference, and thus a crash.

The problem occurs because unused entries in the percpu vector_irq array are filled with VECTOR_IRQ_UNASSIGNED (-1). When a spurious interrupt occurs ia64_handle_irq() calls:

generic_handle_irq(local_vector_to_irq(vector))

and the local_vector_to_irq(vector) part return -1, which is all bad.

If we initialize the unused entried to IA64_SPURIOUS_INT_VECTOR instead, then we get the orginal behaviour: a message is printed and the vector/irq is disabled.

As a bonus we can delete the VECTOR_IRQ_UNASSIGNED define altogether (which is all too easy to confuse with IRQ_VECTOR_UNASSIGNED).

So I applied this patch onto the end of your sequence (but you should merge it into patch8/12).

-Tony

index 91abd1b..ea19ccd 100644
@@ -47,7 +47,6 @@
 #define IRQ_DEBUG	0
 
 #define IRQ_VECTOR_UNASSIGNED	(0)
-#define VECTOR_IRQ_UNASSIGNED	(-1)
 
 #define IRQ_UNUSED		(0)
 #define IRQ_USED		(1)

@@ -83,7 +82,7 @@ struct irq_cfg irq_cfg[NR_IRQS] __read_mostly = {
 };
 
 DEFINE_PER_CPU(int[IA64_NUM_VECTORS], vector_irq) = {
-	[0 ... IA64_NUM_VECTORS - 1] = VECTOR_IRQ_UNASSIGNED
+	[0 ... IA64_NUM_VECTORS - 1] = IA64_SPURIOUS_INT_VECTOR
 };
 
 static cpumask_t vector_table[IA64_MAX_DEVICE_VECTORS] = {

@@ -168,7 +167,7 @@ static void __clear_irq_vector(int irq)
 	domain = irq_cfg[irq].domain;
 	cpus_and(mask, irq_cfg[irq].domain, cpu_online_map);
 	for_each_cpu_mask(cpu, mask)
-		per_cpu(vector_irq, cpu)[vector] = VECTOR_IRQ_UNASSIGNED;
+		per_cpu(vector_irq, cpu)[vector] = IA64_SPURIOUS_INT_VECTOR;
 	irq_cfg[irq].vector = IRQ_VECTOR_UNASSIGNED;
 	irq_cfg[irq].domain = CPU_MASK_NONE;
 	irq_status[irq] = IRQ_UNUSED;

@@ -238,7 +237,7 @@ void __setup_vector_irq(int cpu)
 
 	/* Clear vector_irq */
 	for (vector = 0; vector < IA64_NUM_VECTORS; ++vector)
-		per_cpu(vector_irq, cpu)[vector] = VECTOR_IRQ_UNASSIGNED;
+		per_cpu(vector_irq, cpu)[vector] = IA64_SPURIOUS_INT_VECTOR;
 	/* Mark the inuse vectors */
 	for (irq = 0; irq < NR_IRQS; ++irq) {
 		if (!cpu_isset(cpu, irq_cfg[irq].domain))

Hi Tony,

Thank you for your help.

After reviewing this patch, I'll test and repost vector domain patcheset for 2.6.22.

Thanks,
Yasuaki Ishimatsu