diff options
Diffstat (limited to 'arch/powerpc/kernel/irq.c')
| -rw-r--r-- | arch/powerpc/kernel/irq.c | 653 |
1 files changed, 516 insertions, 137 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index e3774f6b57c..8cf987809c6 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -29,6 +29,8 @@ * to reduce code space and undefined function references. */ +#undef DEBUG + #include <linux/module.h> #include <linux/threads.h> #include <linux/kernel_stat.h> @@ -46,7 +48,10 @@ #include <linux/cpumask.h> #include <linux/profile.h> #include <linux/bitops.h> -#include <linux/pci.h> +#include <linux/list.h> +#include <linux/radix-tree.h> +#include <linux/mutex.h> +#include <linux/bootmem.h> #include <asm/uaccess.h> #include <asm/system.h> @@ -57,39 +62,38 @@ #include <asm/prom.h> #include <asm/ptrace.h> #include <asm/machdep.h> +#include <asm/udbg.h> #ifdef CONFIG_PPC_ISERIES #include <asm/paca.h> #endif int __irq_offset_value; -#ifdef CONFIG_PPC32 -EXPORT_SYMBOL(__irq_offset_value); -#endif - static int ppc_spurious_interrupts; #ifdef CONFIG_PPC32 -#define NR_MASK_WORDS ((NR_IRQS + 31) / 32) +EXPORT_SYMBOL(__irq_offset_value); +atomic_t ppc_n_lost_interrupts; +#ifndef CONFIG_PPC_MERGE +#define NR_MASK_WORDS ((NR_IRQS + 31) / 32) unsigned long ppc_cached_irq_mask[NR_MASK_WORDS]; -atomic_t ppc_n_lost_interrupts; +#endif #ifdef CONFIG_TAU_INT extern int tau_initialized; extern int tau_interrupts(int); #endif +#endif /* CONFIG_PPC32 */ #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE) extern atomic_t ipi_recv; extern atomic_t ipi_sent; #endif -#endif /* CONFIG_PPC32 */ #ifdef CONFIG_PPC64 EXPORT_SYMBOL(irq_desc); int distribute_irqs = 1; -u64 ppc64_interrupt_controller; #endif /* CONFIG_PPC64 */ int show_interrupts(struct seq_file *p, void *v) @@ -182,7 +186,7 @@ void fixup_irqs(cpumask_t map) void do_IRQ(struct pt_regs *regs) { - int irq; + unsigned int irq; #ifdef CONFIG_IRQSTACKS struct thread_info *curtp, *irqtp; #endif @@ -213,22 +217,26 @@ void do_IRQ(struct pt_regs *regs) */ irq = ppc_md.get_irq(regs); - if (irq >= 0) { + if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) { #ifdef CONFIG_IRQSTACKS /* Switch to the irq stack to handle this */ curtp = current_thread_info(); irqtp = hardirq_ctx[smp_processor_id()]; if (curtp != irqtp) { + struct irq_desc *desc = irq_desc + irq; + void *handler = desc->handle_irq; + if (handler == NULL) + handler = &__do_IRQ; irqtp->task = curtp->task; irqtp->flags = 0; - call___do_IRQ(irq, regs, irqtp); + call_handle_irq(irq, desc, regs, irqtp, handler); irqtp->task = NULL; if (irqtp->flags) set_bits(irqtp->flags, &curtp->flags); } else #endif - __do_IRQ(irq, regs); - } else if (irq != -2) + generic_handle_irq(irq, regs); + } else if (irq != NO_IRQ_IGNORE) /* That's not SMP safe ... but who cares ? */ ppc_spurious_interrupts++; @@ -245,191 +253,562 @@ void do_IRQ(struct pt_regs *regs) void __init init_IRQ(void) { + ppc_md.init_IRQ(); #ifdef CONFIG_PPC64 - static int once = 0; + irq_ctx_init(); +#endif +} + + +#ifdef CONFIG_IRQSTACKS +struct thread_info *softirq_ctx[NR_CPUS] __read_mostly; +struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly; + +void irq_ctx_init(void) +{ + struct thread_info *tp; + int i; + + for_each_possible_cpu(i) { + memset((void *)softirq_ctx[i], 0, THREAD_SIZE); + tp = softirq_ctx[i]; + tp->cpu = i; + tp->preempt_count = SOFTIRQ_OFFSET; + + memset((void *)hardirq_ctx[i], 0, THREAD_SIZE); + tp = hardirq_ctx[i]; + tp->cpu = i; + tp->preempt_count = HARDIRQ_OFFSET; + } +} + +static inline void do_softirq_onstack(void) +{ + struct thread_info *curtp, *irqtp; + + curtp = current_thread_info(); + irqtp = softirq_ctx[smp_processor_id()]; + irqtp->task = curtp->task; + call_do_softirq(irqtp); + irqtp->task = NULL; +} - if (once) +#else +#define do_softirq_onstack() __do_softirq() +#endif /* CONFIG_IRQSTACKS */ + +void do_softirq(void) +{ + unsigned long flags; + + if (in_interrupt()) return; - once++; + local_irq_save(flags); -#endif - ppc_md.init_IRQ(); -#ifdef CONFIG_PPC64 - irq_ctx_init(); -#endif + if (local_softirq_pending()) + do_softirq_onstack(); + + local_irq_restore(flags); } +EXPORT_SYMBOL(do_softirq); + -#ifdef CONFIG_PPC64 /* - * Virtual IRQ mapping code, used on systems with XICS interrupt controllers. + * IRQ controller and virtual interrupts */ -#define UNDEFINED_IRQ 0xffffffff -unsigned int virt_irq_to_real_map[NR_IRQS]; +#ifdef CONFIG_PPC_MERGE -/* - * Don't use virtual irqs 0, 1, 2 for devices. - * The pcnet32 driver considers interrupt numbers < 2 to be invalid, - * and 2 is the XICS IPI interrupt. - * We limit virtual irqs to __irq_offet_value less than virt_irq_max so - * that when we offset them we don't end up with an interrupt - * number >= virt_irq_max. - */ -#define MIN_VIRT_IRQ 3 +static LIST_HEAD(irq_hosts); +static spinlock_t irq_big_lock = SPIN_LOCK_UNLOCKED; -unsigned int virt_irq_max; -static unsigned int max_virt_irq; -static unsigned int nr_virt_irqs; +struct irq_map_entry irq_map[NR_IRQS]; +static unsigned int irq_virq_count = NR_IRQS; +static struct irq_host *irq_default_host; -void -virt_irq_init(void) +struct irq_host *irq_alloc_host(unsigned int revmap_type, + unsigned int revmap_arg, + struct irq_host_ops *ops, + irq_hw_number_t inval_irq) { - int i; + struct irq_host *host; + unsigned int size = sizeof(struct irq_host); + unsigned int i; + unsigned int *rmap; + unsigned long flags; + + /* Allocate structure and revmap table if using linear mapping */ + if (revmap_type == IRQ_HOST_MAP_LINEAR) + size += revmap_arg * sizeof(unsigned int); + if (mem_init_done) + host = kzalloc(size, GFP_KERNEL); + else { + host = alloc_bootmem(size); + if (host) + memset(host, 0, size); + } + if (host == NULL) + return NULL; - if ((virt_irq_max == 0) || (virt_irq_max > (NR_IRQS - 1))) - virt_irq_max = NR_IRQS - 1; - max_virt_irq = virt_irq_max - __irq_offset_value; - nr_virt_irqs = max_virt_irq - MIN_VIRT_IRQ + 1; + /* Fill structure */ + host->revmap_type = revmap_type; + host->inval_irq = inval_irq; + host->ops = ops; - for (i = 0; i < NR_IRQS; i++) - virt_irq_to_real_map[i] = UNDEFINED_IRQ; + spin_lock_irqsave(&irq_big_lock, flags); + + /* If it's a legacy controller, check for duplicates and + * mark it as allocated (we use irq 0 host pointer for that + */ + if (revmap_type == IRQ_HOST_MAP_LEGACY) { + if (irq_map[0].host != NULL) { + spin_unlock_irqrestore(&irq_big_lock, flags); + /* If we are early boot, we can't free the structure, + * too bad... + * this will be fixed once slab is made available early + * instead of the current cruft + */ + if (mem_init_done) + kfree(host); + return NULL; + } + irq_map[0].host = host; + } + + list_add(&host->link, &irq_hosts); + spin_unlock_irqrestore(&irq_big_lock, flags); + + /* Additional setups per revmap type */ + switch(revmap_type) { + case IRQ_HOST_MAP_LEGACY: + /* 0 is always the invalid number for legacy */ + host->inval_irq = 0; + /* setup us as the host for all legacy interrupts */ + for (i = 1; i < NUM_ISA_INTERRUPTS; i++) { + irq_map[i].hwirq = 0; + smp_wmb(); + irq_map[i].host = host; + smp_wmb(); + + /* Clear some flags */ + get_irq_desc(i)->status + &= ~(IRQ_NOREQUEST | IRQ_LEVEL); + + /* Legacy flags are left to default at this point, + * one can then use irq_create_mapping() to + * explicitely change them + */ + ops->map(host, i, i, 0); + } + break; + case IRQ_HOST_MAP_LINEAR: + rmap = (unsigned int *)(host + 1); + for (i = 0; i < revmap_arg; i++) + rmap[i] = IRQ_NONE; + host->revmap_data.linear.size = revmap_arg; + smp_wmb(); + host->revmap_data.linear.revmap = rmap; + break; + default: + break; + } + + pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host); + + return host; } -/* Create a mapping for a real_irq if it doesn't already exist. - * Return the virtual irq as a convenience. - */ -int virt_irq_create_mapping(unsigned int real_irq) +struct irq_host *irq_find_host(struct device_node *node) { - unsigned int virq, first_virq; - static int warned; + struct irq_host *h, *found = NULL; + unsigned long flags; + + /* We might want to match the legacy controller last since + * it might potentially be set to match all interrupts in + * the absence of a device node. This isn't a problem so far + * yet though... + */ + spin_lock_irqsave(&irq_big_lock, flags); + list_for_each_entry(h, &irq_hosts, link) + if (h->ops->match == NULL || h->ops->match(h, node)) { + found = h; + break; + } + spin_unlock_irqrestore(&irq_big_lock, flags); + return found; +} +EXPORT_SYMBOL_GPL(irq_find_host); + +void irq_set_default_host(struct irq_host *host) +{ + pr_debug("irq: Default host set to @0x%p\n", host); - if (ppc64_interrupt_controller == IC_OPEN_PIC) - return real_irq; /* no mapping for openpic (for now) */ + irq_default_host = host; +} - if (ppc64_interrupt_controller == IC_CELL_PIC) - return real_irq; /* no mapping for iic either */ +void irq_set_virq_count(unsigned int count) +{ + pr_debug("irq: Trying to set virq count to %d\n", count); - /* don't map interrupts < MIN_VIRT_IRQ */ - if (real_irq < MIN_VIRT_IRQ) { - virt_irq_to_real_map[real_irq] = real_irq; - return real_irq; + BUG_ON(count < NUM_ISA_INTERRUPTS); + if (count < NR_IRQS) + irq_virq_count = count; +} + +unsigned int irq_create_mapping(struct irq_host *host, + irq_hw_number_t hwirq, + unsigned int flags) +{ + unsigned int virq, hint; + + pr_debug("irq: irq_create_mapping(0x%p, 0x%lx, 0x%x)\n", + host, hwirq, flags); + + /* Look for default host if nececssary */ + if (host == NULL) + host = irq_default_host; + if (host == NULL) { + printk(KERN_WARNING "irq_create_mapping called for" + " NULL host, hwirq=%lx\n", hwirq); + WARN_ON(1); + return NO_IRQ; } + pr_debug("irq: -> using host @%p\n", host); - /* map to a number between MIN_VIRT_IRQ and max_virt_irq */ - virq = real_irq; - if (virq > max_virt_irq) - virq = (virq % nr_virt_irqs) + MIN_VIRT_IRQ; - - /* search for this number or a free slot */ - first_virq = virq; - while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) { - if (virt_irq_to_real_map[virq] == real_irq) - return virq; - if (++virq > max_virt_irq) - virq = MIN_VIRT_IRQ; - if (virq == first_virq) - goto nospace; /* oops, no free slots */ + /* Check if mapping already exist, if it does, call + * host->ops->map() to update the flags + */ + virq = irq_find_mapping(host, hwirq); + if (virq != IRQ_NONE) { + pr_debug("irq: -> existing mapping on virq %d\n", virq); + host->ops->map(host, virq, hwirq, flags); + return virq; } - virt_irq_to_real_map[virq] = real_irq; + /* Get a virtual interrupt number */ + if (host->revmap_type == IRQ_HOST_MAP_LEGACY) { + /* Handle legacy */ + virq = (unsigned int)hwirq; + if (virq == 0 || virq >= NUM_ISA_INTERRUPTS) + return NO_IRQ; + return virq; + } else { + /* Allocate a virtual interrupt number */ + hint = hwirq % irq_virq_count; + virq = irq_alloc_virt(host, 1, hint); + if (virq == NO_IRQ) { + pr_debug("irq: -> virq allocation failed\n"); + return NO_IRQ; + } + } + pr_debug("irq: -> obtained virq %d\n", virq); + + /* Clear some flags */ + get_irq_desc(virq)->status &= ~(IRQ_NOREQUEST | IRQ_LEVEL); + + /* map it */ + if (host->ops->map(host, virq, hwirq, flags)) { + pr_debug("irq: -> mapping failed, freeing\n"); + irq_free_virt(virq, 1); + return NO_IRQ; + } + smp_wmb(); + irq_map[virq].hwirq = hwirq; + smp_mb(); return virq; +} +EXPORT_SYMBOL_GPL(irq_create_mapping); + +extern unsigned int irq_create_of_mapping(struct device_node *controller, + u32 *intspec, unsigned int intsize) +{ + struct irq_host *host; + irq_hw_number_t hwirq; + unsigned int flags = IRQ_TYPE_NONE; - nospace: - if (!warned) { - printk(KERN_CRIT "Interrupt table is full\n"); - printk(KERN_CRIT "Increase virt_irq_max (currently %d) " - "in your kernel sources and rebuild.\n", virt_irq_max); - warned = 1; + if (controller == NULL) + host = irq_default_host; + else + host = irq_find_host(controller); + if (host == NULL) + return NO_IRQ; + + /* If host has no translation, then we assume interrupt line */ + if (host->ops->xlate == NULL) + hwirq = intspec[0]; + else { + if (host->ops->xlate(host, controller, intspec, intsize, + &hwirq, &flags)) + return NO_IRQ; } - return NO_IRQ; + + return irq_create_mapping(host, hwirq, flags); } +EXPORT_SYMBOL_GPL(irq_create_of_mapping); -/* - * In most cases will get a hit on the very first slot checked in the - * virt_irq_to_real_map. Only when there are a large number of - * IRQs will this be expensive. - */ -unsigned int real_irq_to_virt_slowpath(unsigned int real_irq) +unsigned int irq_of_parse_and_map(struct device_node *dev, int index) { - unsigned int virq; - unsigned int first_virq; + struct of_irq oirq; - virq = real_irq; + if (of_irq_map_one(dev, index, &oirq)) + return NO_IRQ; - if (virq > max_virt_irq) - virq = (virq % nr_virt_irqs) + MIN_VIRT_IRQ; + return irq_create_of_mapping(oirq.controller, oirq.specifier, + oirq.size); +} +EXPORT_SYMBOL_GPL(irq_of_parse_and_map); - first_virq = virq; +void irq_dispose_mapping(unsigned int virq) +{ + struct irq_host *host = irq_map[virq].host; + irq_hw_number_t hwirq; + unsigned long flags; - do { - if (virt_irq_to_real_map[virq] == real_irq) - return virq; + WARN_ON (host == NULL); + if (host == NULL) + return; - virq++; + /* Never unmap legacy interrupts */ + if (host->revmap_type == IRQ_HOST_MAP_LEGACY) + return; - if (virq >= max_virt_irq) - virq = 0; + /* remove chip and handler */ + set_irq_chip_and_handler(virq, NULL, NULL); + + /* Make sure it's completed */ + synchronize_irq(virq); + + /* Tell the PIC about it */ + if (host->ops->unmap) + host->ops->unmap(host, virq); + smp_mb(); + + /* Clear reverse map */ + hwirq = irq_map[virq].hwirq; + switch(host->revmap_type) { + case IRQ_HOST_MAP_LINEAR: + if (hwirq < host->revmap_data.linear.size) + host->revmap_data.linear.revmap[hwirq] = IRQ_NONE; + break; + case IRQ_HOST_MAP_TREE: + /* Check if radix tree allocated yet */ + if (host->revmap_data.tree.gfp_mask == 0) + break; + /* XXX radix tree not safe ! remove lock whem it becomes safe + * and use some RCU sync to make sure everything is ok before we + * can re-use that map entry + */ + spin_lock_irqsave(&irq_big_lock, flags); + radix_tree_delete(&host->revmap_data.tree, hwirq); + spin_unlock_irqrestore(&irq_big_lock, flags); + break; + } - } while (first_virq != virq); + /* Destroy map */ + smp_mb(); + irq_map[virq].hwirq = host->inval_irq; - return NO_IRQ; + /* Set some flags */ + get_irq_desc(virq)->status |= IRQ_NOREQUEST; + /* Free it */ + irq_free_virt(virq, 1); } -#endif /* CONFIG_PPC64 */ +EXPORT_SYMBOL_GPL(irq_dispose_mapping); -#ifdef CONFIG_IRQSTACKS -struct thread_info *softirq_ctx[NR_CPUS] __read_mostly; -struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly; +unsigned int irq_find_mapping(struct irq_host *host, + irq_hw_number_t hwirq) +{ + unsigned int i; + unsigned int hint = hwirq % irq_virq_count; + + /* Look for default host if nececssary */ + if (host == NULL) + host = irq_default_host; + if (host == NULL) + return NO_IRQ; + + /* legacy -> bail early */ + if (host->revmap_type == IRQ_HOST_MAP_LEGACY) + return hwirq; + + /* Slow path does a linear search of the map */ + if (hint < NUM_ISA_INTERRUPTS) + hint = NUM_ISA_INTERRUPTS; + i = hint; + do { + if (irq_map[i].host == host && + irq_map[i].hwirq == hwirq) + return i; + i++; + if (i >= irq_virq_count) + i = NUM_ISA_INTERRUPTS; + } while(i != hint); + return NO_IRQ; +} +EXPORT_SYMBOL_GPL(irq_find_mapping); -void irq_ctx_init(void) + +unsigned int irq_radix_revmap(struct irq_host *host, + irq_hw_number_t hwirq) { - struct thread_info *tp; - int i; + struct radix_tree_root *tree; + struct irq_map_entry *ptr; + unsigned int virq; + unsigned long flags; - for_each_possible_cpu(i) { - memset((void *)softirq_ctx[i], 0, THREAD_SIZE); - tp = softirq_ctx[i]; - tp->cpu = i; - tp->preempt_count = SOFTIRQ_OFFSET; + WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE); - memset((void *)hardirq_ctx[i], 0, THREAD_SIZE); - tp = hardirq_ctx[i]; - tp->cpu = i; - tp->preempt_count = HARDIRQ_OFFSET; + /* Check if the radix tree exist yet. We test the value of + * the gfp_mask for that. Sneaky but saves another int in the + * structure. If not, we fallback to slow mode + */ + tree = &host->revmap_data.tree; + if (tree->gfp_mask == 0) + return irq_find_mapping(host, hwirq); + + /* XXX Current radix trees are NOT SMP safe !!! Remove that lock + * when that is fixed (when Nick's patch gets in + */ + spin_lock_irqsave(&irq_big_lock, flags); + + /* Now try to resolve */ + ptr = radix_tree_lookup(tree, hwirq); + /* Found it, return */ + if (ptr) { + virq = ptr - irq_map; + goto bail; } + + /* If not there, try to insert it */ + virq = irq_find_mapping(host, hwirq); + if (virq != NO_IRQ) + radix_tree_insert(tree, virq, &irq_map[virq]); + bail: + spin_unlock_irqrestore(&irq_big_lock, flags); + return virq; } -static inline void do_softirq_onstack(void) +unsigned int irq_linear_revmap(struct irq_host *host, + irq_hw_number_t hwirq) { - struct thread_info *curtp, *irqtp; + unsigned int *revmap; - curtp = current_thread_info(); - irqtp = softirq_ctx[smp_processor_id()]; - irqtp->task = curtp->task; - call_do_softirq(irqtp); - irqtp->task = NULL; + WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR); + + /* Check revmap bounds */ + if (unlikely(hwirq >= host->revmap_data.linear.size)) + return irq_find_mapping(host, hwirq); + + /* Check if revmap was allocated */ + revmap = host->revmap_data.linear.revmap; + if (unlikely(revmap == NULL)) + return irq_find_mapping(host, hwirq); + + /* Fill up revmap with slow path if no mapping found */ + if (unlikely(revmap[hwirq] == NO_IRQ)) + revmap[hwirq] = irq_find_mapping(host, hwirq); + + return revmap[hwirq]; } -#else -#define do_softirq_onstack() __do_softirq() -#endif /* CONFIG_IRQSTACKS */ +unsigned int irq_alloc_virt(struct irq_host *host, + unsigned int count, + unsigned int hint) +{ + unsigned long flags; + unsigned int i, j, found = NO_IRQ; + unsigned int limit = irq_virq_count - count; -void do_softirq(void) + if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS)) + return NO_IRQ; + + spin_lock_irqsave(&irq_big_lock, flags); + + /* Use hint for 1 interrupt if any */ + if (count == 1 && hint >= NUM_ISA_INTERRUPTS && + hint < irq_virq_count && irq_map[hint].host == NULL) { + found = hint; + goto hint_found; + } + + /* Look for count consecutive numbers in the allocatable + * (non-legacy) space + */ + for (i = NUM_ISA_INTERRUPTS; i <= limit; ) { + for (j = i; j < (i + count); j++) + if (irq_map[j].host != NULL) { + i = j + 1; + continue; + } + found = i; + break; + } + if (found == NO_IRQ) { + spin_unlock_irqrestore(&irq_big_lock, flags); + return NO_IRQ; + } + hint_found: + for (i = found; i < (found + count); i++) { + irq_map[i].hwirq = host->inval_irq; + smp_wmb(); + irq_map[i].host = host; + } + spin_unlock_irqrestore(&irq_big_lock, flags); + return found; +} + +void irq_free_virt(unsigned int virq, unsigned int count) { unsigned long flags; + unsigned int i; - if (in_interrupt()) - return; + WARN_ON (virq < NUM_ISA_INTERRUPTS); + WARN_ON (count == 0 || (virq + count) > irq_virq_count); - local_irq_save(flags); + spin_lock_irqsave(&irq_big_lock, flags); + for (i = virq; i < (virq + count); i++) { + struct irq_host *host; - if (local_softirq_pending()) - do_softirq_onstack(); + if (i < NUM_ISA_INTERRUPTS || + (virq + count) > irq_virq_count) + continue; - local_irq_restore(flags); + host = irq_map[i].host; + irq_map[i].hwirq = host->inval_irq; + smp_wmb(); + irq_map[i].host = NULL; + } + spin_unlock_irqrestore(&irq_big_lock, flags); } -EXPORT_SYMBOL(do_softirq); + +void irq_early_init(void) +{ + unsigned int i; + + for (i = 0; i < NR_IRQS; i++) + get_irq_desc(i)->status |= IRQ_NOREQUEST; +} + +/* We need to create the radix trees late */ +static int irq_late_init(void) +{ + struct irq_host *h; + unsigned long flags; + + spin_lock_irqsave(&irq_big_lock, flags); + list_for_each_entry(h, &irq_hosts, link) { + if (h->revmap_type == IRQ_HOST_MAP_TREE) + INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC); + } + spin_unlock_irqrestore(&irq_big_lock, flags); + + return 0; +} +arch_initcall(irq_late_init); + +#endif /* CONFIG_PPC_MERGE */ #ifdef CONFIG_PCI_MSI int pci_enable_msi(struct pci_dev * pdev) |