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genirq: Create irq_data
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Low level chip functions need access to irq_desc->handler_data,
irq_desc->chip_data and irq_desc->msi_desc. We hand down the irq
number to the low level functions, so they need to lookup irq_desc.
With sparse irq this means a radix tree lookup.

We could hand down irq_desc itself, but low level chip functions have
no need to fiddle with it directly and we want to restrict access to
irq_desc further.

Preparatory patch for new chip functions.

Note, that the ugly anon union/struct is there to avoid a full tree
wide clean up for now. This is not going to last 3 years like __do_IRQ()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121841.645542300@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
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Thomas Gleixner committed Oct 4, 2010
1 parent 3bb9808 commit ff7dcd4
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Showing 2 changed files with 82 additions and 47 deletions.
90 changes: 63 additions & 27 deletions include/linux/irq.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -83,6 +83,37 @@ typedef void (*irq_flow_handler_t)(unsigned int irq,
struct proc_dir_entry;
struct msi_desc;

/**
* struct irq_data - per irq and irq chip data passed down to chip functions
* @irq: interrupt number
* @node: node index useful for balancing
* @chip: low level interrupt hardware access
* @handler_data: per-IRQ data for the irq_chip methods
* @chip_data: platform-specific per-chip private data for the chip
* methods, to allow shared chip implementations
* @msi_desc: MSI descriptor
* @affinity: IRQ affinity on SMP
* @irq_2_iommu: iommu with this irq
*
* The fields here need to overlay the ones in irq_desc until we
* cleaned up the direct references and switched everything over to
* irq_data.
*/
struct irq_data {
unsigned int irq;
unsigned int node;
struct irq_chip *chip;
void *handler_data;
void *chip_data;
struct msi_desc *msi_desc;
#ifdef CONFIG_SMP
cpumask_var_t affinity;
#endif
#ifdef CONFIG_INTR_REMAP
struct irq_2_iommu *irq_2_iommu;
#endif
};

/**
* struct irq_chip - hardware interrupt chip descriptor
*
Expand Down Expand Up @@ -140,16 +171,10 @@ struct timer_rand_state;
struct irq_2_iommu;
/**
* struct irq_desc - interrupt descriptor
* @irq: interrupt number for this descriptor
* @irq_data: per irq and chip data passed down to chip functions
* @timer_rand_state: pointer to timer rand state struct
* @kstat_irqs: irq stats per cpu
* @irq_2_iommu: iommu with this irq
* @handle_irq: highlevel irq-events handler [if NULL, __do_IRQ()]
* @chip: low level interrupt hardware access
* @msi_desc: MSI descriptor
* @handler_data: per-IRQ data for the irq_chip methods
* @chip_data: platform-specific per-chip private data for the chip
* methods, to allow shared chip implementations
* @action: the irq action chain
* @status: status information
* @depth: disable-depth, for nested irq_disable() calls
Expand All @@ -158,26 +183,39 @@ struct irq_2_iommu;
* @last_unhandled: aging timer for unhandled count
* @irqs_unhandled: stats field for spurious unhandled interrupts
* @lock: locking for SMP
* @affinity: IRQ affinity on SMP
* @node: node index useful for balancing
* @pending_mask: pending rebalanced interrupts
* @threads_active: number of irqaction threads currently running
* @wait_for_threads: wait queue for sync_irq to wait for threaded handlers
* @dir: /proc/irq/ procfs entry
* @name: flow handler name for /proc/interrupts output
*/
struct irq_desc {
unsigned int irq;
struct timer_rand_state *timer_rand_state;
unsigned int *kstat_irqs;

/*
* This union will go away, once we fixed the direct access to
* irq_desc all over the place. The direct fields are a 1:1
* overlay of irq_data.
*/
union {
struct irq_data irq_data;
struct {
unsigned int irq;
unsigned int node;
struct irq_chip *chip;
void *handler_data;
void *chip_data;
struct msi_desc *msi_desc;
#ifdef CONFIG_SMP
cpumask_var_t affinity;
#endif
#ifdef CONFIG_INTR_REMAP
struct irq_2_iommu *irq_2_iommu;
struct irq_2_iommu *irq_2_iommu;
#endif
};
};
struct timer_rand_state *timer_rand_state;
unsigned int *kstat_irqs;
irq_flow_handler_t handle_irq;
struct irq_chip *chip;
struct msi_desc *msi_desc;
void *handler_data;
void *chip_data;
struct irqaction *action; /* IRQ action list */
unsigned int status; /* IRQ status */

Expand All @@ -188,9 +226,7 @@ struct irq_desc {
unsigned int irqs_unhandled;
raw_spinlock_t lock;
#ifdef CONFIG_SMP
cpumask_var_t affinity;
const struct cpumask *affinity_hint;
unsigned int node;
#ifdef CONFIG_GENERIC_PENDING_IRQ
cpumask_var_t pending_mask;
#endif
Expand Down Expand Up @@ -406,15 +442,15 @@ extern int set_irq_chip_data(unsigned int irq, void *data);
extern int set_irq_type(unsigned int irq, unsigned int type);
extern int set_irq_msi(unsigned int irq, struct msi_desc *entry);

#define get_irq_chip(irq) (irq_to_desc(irq)->chip)
#define get_irq_chip_data(irq) (irq_to_desc(irq)->chip_data)
#define get_irq_data(irq) (irq_to_desc(irq)->handler_data)
#define get_irq_msi(irq) (irq_to_desc(irq)->msi_desc)
#define get_irq_chip(irq) (irq_to_desc(irq)->irq_data.chip)
#define get_irq_chip_data(irq) (irq_to_desc(irq)->irq_data.chip_data)
#define get_irq_data(irq) (irq_to_desc(irq)->irq_data.handler_data)
#define get_irq_msi(irq) (irq_to_desc(irq)->irq_data.msi_desc)

#define get_irq_desc_chip(desc) ((desc)->chip)
#define get_irq_desc_chip_data(desc) ((desc)->chip_data)
#define get_irq_desc_data(desc) ((desc)->handler_data)
#define get_irq_desc_msi(desc) ((desc)->msi_desc)
#define get_irq_desc_chip(desc) ((desc)->irq_data.chip)
#define get_irq_desc_chip_data(desc) ((desc)->irq_data.chip_data)
#define get_irq_desc_data(desc) ((desc)->irq_data.handler_data)
#define get_irq_desc_msi(desc) ((desc)->irq_data.msi_desc)

#endif /* CONFIG_GENERIC_HARDIRQS */

Expand Down
39 changes: 19 additions & 20 deletions kernel/irq/handle.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -75,12 +75,10 @@ EXPORT_SYMBOL_GPL(nr_irqs);
#ifdef CONFIG_SPARSE_IRQ

static struct irq_desc irq_desc_init = {
.irq = -1,
.status = IRQ_DISABLED,
.chip = &no_irq_chip,
.handle_irq = handle_bad_irq,
.depth = 1,
.lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
.status = IRQ_DISABLED,
.handle_irq = handle_bad_irq,
.depth = 1,
.lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
};

void __ref init_kstat_irqs(struct irq_desc *desc, int node, int nr)
Expand All @@ -105,7 +103,7 @@ static void init_one_irq_desc(int irq, struct irq_desc *desc, int node)
memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));

raw_spin_lock_init(&desc->lock);
desc->irq = irq;
desc->irq_data.irq = irq;
#ifdef CONFIG_SMP
desc->node = node;
#endif
Expand Down Expand Up @@ -151,12 +149,10 @@ void replace_irq_desc(unsigned int irq, struct irq_desc *desc)

static struct irq_desc irq_desc_legacy[NR_IRQS_LEGACY] __cacheline_aligned_in_smp = {
[0 ... NR_IRQS_LEGACY-1] = {
.irq = -1,
.status = IRQ_DISABLED,
.chip = &no_irq_chip,
.handle_irq = handle_bad_irq,
.depth = 1,
.lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
.status = IRQ_DISABLED,
.handle_irq = handle_bad_irq,
.depth = 1,
.lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
}
};

Expand All @@ -183,8 +179,11 @@ int __init early_irq_init(void)
kstat_irqs_legacy = kzalloc_node(NR_IRQS_LEGACY * nr_cpu_ids *
sizeof(int), GFP_NOWAIT, node);

irq_desc_init.irq_data.chip = &no_irq_chip;

for (i = 0; i < legacy_count; i++) {
desc[i].irq = i;
desc[i].irq_data.irq = i;
desc[i].irq_data.chip = &no_irq_chip;
#ifdef CONFIG_SMP
desc[i].node = node;
#endif
Expand Down Expand Up @@ -241,11 +240,10 @@ struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)

struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
[0 ... NR_IRQS-1] = {
.status = IRQ_DISABLED,
.chip = &no_irq_chip,
.handle_irq = handle_bad_irq,
.depth = 1,
.lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
.status = IRQ_DISABLED,
.handle_irq = handle_bad_irq,
.depth = 1,
.lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
}
};

Expand All @@ -264,7 +262,8 @@ int __init early_irq_init(void)
count = ARRAY_SIZE(irq_desc);

for (i = 0; i < count; i++) {
desc[i].irq = i;
desc[i].irq_data.irq = i;
desc[i].irq_data.chip = &no_irq_chip;
alloc_desc_masks(&desc[i], 0, true);
init_desc_masks(&desc[i]);
desc[i].kstat_irqs = kstat_irqs_all[i];
Expand Down

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