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

Signed-off-by: Jiang Liu <jiang....@linux.intel.com>
---
 include/linux/msi.h |   35 ++++++++++++++++++++++++++++++
 kernel/irq/msi.c    |   59 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+)

diff --git a/include/linux/msi.h b/include/linux/msi.h
index 714716a3ffdd..6b356a1410b2 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 +101,26 @@ 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 define msi_alloc_info_t.
+ */
+struct msi_alloc_info {
+       struct msi_desc *desc;
+       irq_hw_number_t hwirq;
+       long            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 +131,19 @@ 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,
+                                      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 +158,8 @@ 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);
+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..0b6665de3a60 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 +127,62 @@ 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 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, &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

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