[PATCH 1/2 v2] irqdomain: add support for creating a continous mapping
Sebastian Andrzej Siewior
bigeasy at linutronix.de
Fri Feb 21 19:57:36 EST 2014
A MSI device may have multiple interrupts. That means that the
interrupts numbers should be continuos so that pdev->irq refers to the
first interrupt, pdev->irq + 1 to the second and so on.
This patch adds support for continuous allocation of virqs for a range
of hwirqs. The function is based on irq_create_mapping() but due to the
number argument there is very little in common now.
Cc: Thomas Gleixner <tglx at linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
---
Scott, this is what you suggested. I must admit, it does not look that
bad. It is just compile tested.
v1.v2:
- use irq_create_mapping_block() for irq_create_mapping()
include/linux/irqdomain.h | 10 ++++--
kernel/irq/irqdomain.c | 87 ++++++++++++++++++++++++++++++++++-------------
2 files changed, 72 insertions(+), 25 deletions(-)
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index c983ed1..8b09a6b 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -171,12 +171,18 @@ extern int irq_domain_associate(struct irq_domain *domain, unsigned int irq,
irq_hw_number_t hwirq);
extern void irq_domain_associate_many(struct irq_domain *domain,
unsigned int irq_base,
irq_hw_number_t hwirq_base, int count);
-extern unsigned int irq_create_mapping(struct irq_domain *host,
- irq_hw_number_t hwirq);
+extern unsigned int irq_create_mapping_block(struct irq_domain *host,
+ irq_hw_number_t hwirq, unsigned int num);
+static inline unsigned int irq_create_mapping(struct irq_domain *host,
+ irq_hw_number_t hwirq)
+{
+ return irq_create_mapping_block(host, hwirq, 1);
+}
+
extern void irq_dispose_mapping(unsigned int virq);
/**
* irq_linear_revmap() - Find a linux irq from a hw irq number.
* @domain: domain owning this hardware interrupt
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index cf68bb3..cdc6627 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -372,67 +372,108 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain)
return virq;
}
EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
+static int irq_check_continuous_mapping(struct irq_domain *domain,
+ irq_hw_number_t hwirq, unsigned int num)
+{
+ int virq;
+ int i;
+
+ virq = irq_find_mapping(domain, hwirq);
+
+ for (i = 1; i < num; i++) {
+ unsigned int next;
+
+ next = irq_find_mapping(domain, hwirq + i);
+ if (next == virq + i)
+ continue;
+
+ pr_err("irq: invalid partial mapping. First hwirq %lu maps to "
+ "%d and \n", hwirq, virq);
+ pr_err("irq: +%d hwirq (%lu) maps to %d but should be %d.\n",
+ i, hwirq + i, next, virq + i);
+ return -EINVAL;
+ }
+
+ pr_debug("-> existing mapping on virq %d\n", virq);
+ return virq;
+}
+
/**
- * irq_create_mapping() - Map a hardware interrupt into linux irq space
+ * irq_create_mapping_block() - Map multiple hardware interrupts
* @domain: domain owning this hardware interrupt or NULL for default domain
* @hwirq: hardware irq number in that domain space
+ * @num: number of interrupts
+ *
+ * Maps a hwirq to a newly allocated virq. If num is greater than 1 then num
+ * hwirqs (hwirq … hwirq + num - 1) will be mapped and virq will be continuous.
+ * Returns the first linux virq number.
*
- * Only one mapping per hardware interrupt is permitted. Returns a linux
- * irq number.
* If the sense/trigger is to be specified, set_irq_type() should be called
* on the number returned from that call.
*/
-unsigned int irq_create_mapping(struct irq_domain *domain,
- irq_hw_number_t hwirq)
+unsigned int irq_create_mapping_block(struct irq_domain *domain,
+ irq_hw_number_t hwirq, unsigned int num)
{
- unsigned int hint;
int virq;
+ int i;
+ int node;
+ unsigned int hint;
- pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);
+ pr_debug("%s(0x%p, 0x%lx, %d)\n", __func__, domain, hwirq, num);
/* Look for default domain if nececssary */
- if (domain == NULL)
+ if (!domain && num == 1)
domain = irq_default_domain;
+
if (domain == NULL) {
WARN(1, "%s(, %lx) called with NULL domain\n", __func__, hwirq);
return 0;
}
pr_debug("-> using domain @%p\n", domain);
/* Check if mapping already exists */
- virq = irq_find_mapping(domain, hwirq);
- if (virq) {
- pr_debug("-> existing mapping on virq %d\n", virq);
- return virq;
+ for (i = 0; i < num; i++) {
+ virq = irq_find_mapping(domain, hwirq + i);
+ if (virq != NO_IRQ) {
+ if (i == 0)
+ return irq_check_continuous_mapping(domain,
+ hwirq, num);
+ pr_err("irq: hwirq %ld has no mapping but hwirq %ld "
+ "maps to virq %d. This can't be a block\n",
+ hwirq, hwirq + i, virq);
+ return -EINVAL;
+ }
}
+ node = of_node_to_nid(domain->of_node);
/* Allocate a virtual interrupt number */
hint = hwirq % nr_irqs;
if (hint == 0)
hint++;
- virq = irq_alloc_desc_from(hint, of_node_to_nid(domain->of_node));
- if (virq <= 0)
- virq = irq_alloc_desc_from(1, of_node_to_nid(domain->of_node));
+ virq = irq_alloc_descs_from(hint, num, node);
+ if (virq <= 0 && hint != 1)
+ virq = irq_alloc_descs_from(1, num, node);
if (virq <= 0) {
pr_debug("-> virq allocation failed\n");
return 0;
}
- if (irq_domain_associate(domain, virq, hwirq)) {
- irq_free_desc(virq);
- return 0;
+ irq_domain_associate_many(domain, virq, hwirq, num);
+ if (num == 1) {
+ pr_debug("irq %lu on domain %s mapped to virtual irq %u\n",
+ hwirq, of_node_full_name(domain->of_node), virq);
+ return virq;
}
-
- pr_debug("irq %lu on domain %s mapped to virtual irq %u\n",
- hwirq, of_node_full_name(domain->of_node), virq);
-
+ pr_debug("irqs %lu…%lu on domain %s mapped to virtual irqs %u…%u\n",
+ hwirq, hwirq + num - 1, of_node_full_name(domain->of_node),
+ virq, virq + num - 1);
return virq;
}
-EXPORT_SYMBOL_GPL(irq_create_mapping);
+EXPORT_SYMBOL_GPL(irq_create_mapping_block);
/**
* irq_create_strict_mappings() - Map a range of hw irqs to fixed linux irqs
* @domain: domain owning the interrupt range
* @irq_base: beginning of linux IRQ range
--
1.9.0.rc3
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