[Patch V2 6/9] genirq: Introduce msi_domain_{alloc|free}_irqs()

Jiang Liu
2014-11-15T14:22:50Z

Introduce msi_domain_{alloc|free}_irqs() to alloc/free interrupts
from generic MSI irqdomain.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
include/linux/msi.h | 39 +++++++++++++++++++++++++++++++++
kernel/irq/msi.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 99 insertions(+)

diff --git a/include/linux/msi.h b/include/linux/msi.h
index 714716a3ffdd..7283e155afef 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -3,6 +3,7 @@

#include <linux/kobject.h>
#include <linux/list.h>
+#include <asm/hw_irq.h> /* for msi_alloc_info_t */

struct msi_msg {
u32 address_lo; /* low 32 bits of msi message address */
@@ -100,7 +101,29 @@ struct irq_chip;
struct device_node;
struct msi_domain_info;

+#ifndef NUM_MSI_ALLOC_SCRATCHPAD_REGS
+#define NUM_MSI_ALLOC_SCRATCHPAD_REGS 2
+#endif
+
+/*
+ * Default structure for MSI interrupt allocation.
+ * Arch may overwrite it by defining msi_alloc_info_t.
+ */
+struct msi_alloc_info {
+ struct msi_desc *desc;
+ irq_hw_number_t hwirq;
+ union {
+ unsigned long ul;
+ void *ptr;
+ } scratchpad[NUM_MSI_ALLOC_SCRATCHPAD_REGS];
+};
+
+#ifndef msi_alloc_info_t
+typedef struct msi_alloc_info msi_alloc_info_t;
+#endif
+
struct msi_domain_ops {
+ /* Callbacks for msi_create_irq_domain() */
void (*calc_hwirq)(struct msi_domain_info *info, void *arg,
struct msi_desc *desc);
irq_hw_number_t (*get_hwirq)(struct msi_domain_info *info, void *arg);
@@ -111,6 +134,19 @@ struct msi_domain_ops {
void (*msi_free)(struct irq_domain *domain,
struct msi_domain_info *info,
unsigned int virq);
+
+ /* Callbacks for msi_irq_domain_alloc_irqs() based on msi_descs */
+ int (*msi_check)(struct irq_domain *domain,
+ struct msi_domain_info *info,
+ struct device *dev);
+ int (*msi_prepare)(struct irq_domain *domain,
+ struct device *dev, int nvec,
+ msi_alloc_info_t *arg);
+ void (*msi_finish)(msi_alloc_info_t *arg, int retval);
+ void (*set_desc)(msi_alloc_info_t *arg,
+ struct msi_desc *desc);
+ int (*handle_error)(struct irq_domain *domain,
+ struct msi_desc *desc, int error);
};

struct msi_domain_info {
@@ -125,6 +161,9 @@ int msi_domain_set_affinity(struct irq_data *data, const struct cpumask *mask,
struct irq_domain *msi_create_irq_domain(struct device_node *of_node,
struct msi_domain_info *info,
struct irq_domain *parent);
+int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
+ int nvec);
+void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev);
struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain);

#endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 94d6d87ee23e..ce054566edf5 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -13,6 +13,9 @@
#include <linux/irqdomain.h>
#include <linux/msi.h>

+/* Temparory solution for building, will be removed later */
+#include <linux/pci.h>
+
void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
{
*msg = entry->msg;
@@ -124,6 +127,63 @@ struct irq_domain *msi_create_irq_domain(struct device_node *of_node,
return domain;
}

+int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
+ int nvec)
+{
+ int i, ret, virq = -1;
+ msi_alloc_info_t arg;
+ struct msi_desc *desc;
+ struct msi_domain_info *info = domain->host_data;
+ struct msi_domain_ops *ops = info->ops;
+
+ ret = ops->msi_check(domain, info, dev);
+ if (ret == 0)
+ ret = ops->msi_prepare(domain, dev, nvec, &arg);
+ if (ret)
+ return ret;
+
+ for_each_msi_entry(desc, dev) {
+ ops->set_desc(&arg, desc);
+
+ virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used,
+ dev_to_node(dev), &arg, false);
+ if (virq < 0) {
+ ret = -ENOSPC;
+ if (ops->handle_error)
+ ret = ops->handle_error(domain, desc, ret);
+ if (ops->msi_finish)
+ ops->msi_finish(&arg, ret);
+ return ret;
+ }
+
+ for (i = 0; i < desc->nvec_used; i++)
+ irq_set_msi_desc_off(virq, i, desc);
+ }
+
+ if (ops->msi_finish)
+ ops->msi_finish(&arg, 0);
+
+ for_each_msi_entry(desc, dev) {
+ if (desc->nvec_used == 1)
+ dev_dbg(dev, "irq %d for MSI\n", virq);
+ else
+ dev_dbg(dev, "irq [%d-%d] for MSI\n",
+ virq, virq + desc->nvec_used - 1);
+ }
+
+ return 0;
+}
+
+void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
+{
+ struct msi_desc *desc;
+
+ for_each_msi_entry(desc, dev) {
+ irq_domain_free_irqs(desc->irq, desc->nvec_used);
+ desc->irq = 0;
+ }
+}
+
struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
{
return (struct msi_domain_info *)domain->host_data;
--
1.7.10.4