[PATCH 1/3] irq: Set multiple MSI descriptor data for multiple IRQs

Mike Qiu
2013-01-15T07:39:12Z

Multiple MSI only requires the IRQ in msi_desc entry to be set as
the value of irq_base.

This patch implements the above mentioned technique.

Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>
---
include/linux/irq.h | 2 ++
kernel/irq/chip.c | 40 ++++++++++++++++++++++++++++++----------
2 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index fdf2c4a..60ef45b 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -528,6 +528,8 @@ extern int irq_set_handler_data(unsigned int irq, void *data);
extern int irq_set_chip_data(unsigned int irq, void *data);
extern int irq_set_irq_type(unsigned int irq, unsigned int type);
extern int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry);
+extern int irq_set_multiple_msi_desc(unsigned int irq_base, unsigned int nvec,
+ struct msi_desc *entry);
extern struct irq_data *irq_get_irq_data(unsigned int irq);

static inline struct irq_chip *irq_get_chip(unsigned int irq)
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 3aca9f2..c4c39d3 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -90,6 +90,35 @@ int irq_set_handler_data(unsigned int irq, void *data)
EXPORT_SYMBOL(irq_set_handler_data);

/**
+ * irq_set_multiple_msi_desc - set Multiple MSI descriptor data
+ * for multiple IRQs
+ * @irq_base: Interrupt number base
+ * @nvec: The number of interrupts
+ * @entry: Pointer to MSI descriptor data
+ *
+ * Set IRQ descriptors for multiple MSIs
+ */
+int irq_set_multiple_msi_desc(unsigned int irq_base, unsigned int nvec,
+ struct msi_desc *entry)
+{
+ unsigned long flags, i;
+ struct irq_desc *desc;
+
+ for (i = 0; i < nvec; i++) {
+ desc = irq_get_desc_lock(irq_base + i, &flags,
+ IRQ_GET_DESC_CHECK_GLOBAL);
+ if (!desc)
+ return -EINVAL;
+ desc->irq_data.msi_desc = entry;
+ if (i == 0 && entry)
+ entry->irq = irq_base;
+ irq_put_desc_unlock(desc, flags);
+ }
+
+ return 0;
+}
+
+/**
* irq_set_msi_desc - set MSI descriptor data for an irq
* @irq: Interrupt number
* @entry: Pointer to MSI descriptor data
@@ -98,16 +127,7 @@ EXPORT_SYMBOL(irq_set_handler_data);
*/
int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
{
- unsigned long flags;
- struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
-
- if (!desc)
- return -EINVAL;
- desc->irq_data.msi_desc = entry;
- if (entry)
- entry->irq = irq;
- irq_put_desc_unlock(desc, flags);
- return 0;
+ return irq_set_multiple_msi_desc(irq, 1, entry);
}

/**
--
1.7.7.6