[PATCH 2/3] irq: Add hw continuous IRQs map to virtual continuous IRQs support

Mike Qiu
2013-01-15T07:39:45Z

Adding a function irq_create_mapping_many() which can associate
multiple MSIs to a continous irq mapping.

This is needed to enable multiple MSI support for pSeries.

Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>
---
include/linux/irq.h | 2 +
include/linux/irqdomain.h | 3 ++
kernel/irq/irqdomain.c | 61 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 66 insertions(+), 0 deletions(-)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 60ef45b..e00a7ec 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -592,6 +592,8 @@ int __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
#define irq_alloc_desc_from(from, node) \
irq_alloc_descs(-1, from, 1, node)

+#define irq_alloc_desc_n(nevc, node) \
+ irq_alloc_descs(-1, 0, nevc, node)
void irq_free_descs(unsigned int irq, unsigned int cnt);
int irq_reserve_irqs(unsigned int from, unsigned int cnt);

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 0d5b17b..831dded 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -168,6 +168,9 @@ extern int irq_create_strict_mappings(struct irq_domain *domain,
unsigned int irq_base,
irq_hw_number_t hwirq_base, int count);

+extern int irq_create_mapping_many(struct irq_domain *domain,
+ irq_hw_number_t hwirq_base, int count);
+
static inline int irq_create_identity_mapping(struct irq_domain *host,
irq_hw_number_t hwirq)
{
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 96f3a1d..38648e6 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -636,6 +636,67 @@ int irq_create_strict_mappings(struct irq_domain *domain, unsigned int irq_base,
}
EXPORT_SYMBOL_GPL(irq_create_strict_mappings);

+/**
+ * irq_create_mapping_many - Map a range of hw IRQs to a range of virtual IRQs
+ * @domain: domain owning the interrupt range
+ * @hwirq_base: beginning of continuous hardware IRQ range
+ * @count: Number of interrupts to map
+ *
+ * This routine is used for allocating and mapping a range of hardware
+ * irqs to virtual IRQs where the virtual irq numbers are not at pre-defined
+ * locations.
+ *
+ * Greater than 0 is returned upon success, while any failure to establish a
+ * static mapping is treated as an error.
+ */
+int irq_create_mapping_many(struct irq_domain *domain,
+ irq_hw_number_t hwirq_base, int count)
+{
+ int ret, irq_base;
+ int virq, i;
+
+ pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq_base);
+
+ /* Look for default domain if nececssary */
+ if (!domain)
+ domain = irq_default_domain;
+ if (!domain) {
+ pr_warn("irq_create_mapping called for NULL domain, hwirq=%lx\n"
+ , hwirq_base);
+ WARN_ON(1);
+ return 0;
+ }
+ pr_debug("-> using domain @%p\n", domain);
+
+ /* For IRQ_DOMAIN_MAP_LEGACY, get the first virtual interrupt number */
+ if (domain->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
+ return irq_domain_legacy_revmap(domain, hwirq_base);
+
+ /* Check if mapping already exists */
+ for (i = 0; i < count; i++) {
+ virq = irq_find_mapping(domain, hwirq_base+i);
+ if (virq) {
+ pr_debug("existing mapping on virq %d,"
+ " now dispose it first\n", virq);
+ irq_dispose_mapping(virq);
+ }
+ }
+
+ /* Allocate the continuous virtual interrupt numbers */
+ irq_base = irq_alloc_desc_n(count, of_node_to_nid(domain->of_node));
+ if (unlikely(irq_base < 0))
+ return irq_base;
+
+ ret = irq_domain_associate_many(domain, irq_base, hwirq_base, count);
+ if (unlikely(ret < 0)) {
+ irq_free_descs(irq_base, count);
+ return ret;
+ }
+
+ return irq_base;
+}
+EXPORT_SYMBOL_GPL(irq_create_mapping_many);
+
unsigned int irq_create_of_mapping(struct device_node *controller,
const u32 *intspec, unsigned int intsize)
{
--
1.7.7.6