msi: Kill the msi_desc array.

We need to be able to get from an irq number to a struct msi_desc.
The msi_desc array in msi.c had several short comings the big one was
that it could not be used outside of msi.c.  Using irq_data in struct
irq_desc almost worked except on some architectures irq_data needs to
be used for something else.

So this patch adds a msi_desc pointer to irq_desc, adds the appropriate
wrappers and changes all of the msi code to use them.

The dynamic_irq_init/cleanup code was tweaked to ensure the new
field is left in a well defined state.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 54 insertions, 24 deletions

diff --git a/arch/ia64/sn/kernel/msi_sn.c b/arch/ia64/sn/kernel/msi_sn.c
index b3a435fd70fb..31fbb859b67e 100644
--- a/arch/ia64/sn/kernel/msi_sn.c
+++ b/arch/ia64/sn/kernel/msi_sn.c
@@ -74,7 +74,7 @@ int sn_setup_msi_irq(unsigned int irq, struct pci_dev *pdev)
         struct pcibus_bussoft *bussoft = SN_PCIDEV_BUSSOFT(pdev);
         struct sn_pcibus_provider *provider = SN_PCIDEV_BUSPROVIDER(pdev);
 
-        entry = get_irq_data(irq);
+        entry = get_irq_msi(irq);
         if (!entry->msi_attrib.is_64)
                 return -EINVAL;
 
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 55fe83dfd77b..52c253c5ad3d 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -24,7 +24,6 @@
 #include "pci.h"
 #include "msi.h"
 
-static struct msi_desc* msi_desc[NR_IRQS] = { [0 ... NR_IRQS-1] = NULL };
 static struct kmem_cache* msi_cachep;
 
 static int pci_msi_enable = 1;
@@ -43,7 +42,7 @@ static void msi_set_mask_bit(unsigned int irq, int flag)
 {
         struct msi_desc *entry;
 
-        entry = msi_desc[irq];
+        entry = get_irq_msi(irq);
         BUG_ON(!entry || !entry->dev);
         switch (entry->msi_attrib.type) {
         case PCI_CAP_ID_MSI:
@@ -73,7 +72,7 @@ static void msi_set_mask_bit(unsigned int irq, int flag)
 
 void read_msi_msg(unsigned int irq, struct msi_msg *msg)
 {
-        struct msi_desc *entry = get_irq_data(irq);
+        struct msi_desc *entry = get_irq_msi(irq);
         switch(entry->msi_attrib.type) {
         case PCI_CAP_ID_MSI:
         {
@@ -112,7 +111,7 @@ void read_msi_msg(unsigned int irq, struct msi_msg *msg)
 
 void write_msi_msg(unsigned int irq, struct msi_msg *msg)
 {
-        struct msi_desc *entry = get_irq_data(irq);
+        struct msi_desc *entry = get_irq_msi(irq);
         switch (entry->msi_attrib.type) {
         case PCI_CAP_ID_MSI:
         {
@@ -208,7 +207,7 @@ static int create_msi_irq(void)
                 return -EBUSY;
         }
 
-        set_irq_data(irq, entry);
+        set_irq_msi(irq, entry);
 
         return irq;
 }
@@ -217,9 +216,9 @@ static void destroy_msi_irq(unsigned int irq)
 {
         struct msi_desc *entry;
 
-        entry = get_irq_data(irq);
+        entry = get_irq_msi(irq);
         set_irq_chip(irq, NULL);
-        set_irq_data(irq, NULL);
+        set_irq_msi(irq, NULL);
         destroy_irq(irq);
         kmem_cache_free(msi_cachep, entry);
 }
@@ -360,10 +359,10 @@ static int __pci_save_msix_state(struct pci_dev *dev)
         while (head != tail) {
                 struct msi_desc *entry;
 
-                entry = msi_desc[irq];
+                entry = get_irq_msi(irq);
                 read_msi_msg(irq, &entry->msg_save);
 
-                tail = msi_desc[irq]->link.tail;
+                tail = entry->link.tail;
                 irq = tail;
         }
 
@@ -410,10 +409,10 @@ static void __pci_restore_msix_state(struct pci_dev *dev)
         /* route the table */
         irq = head = dev->first_msi_irq;
         while (head != tail) {
-                entry = msi_desc[irq];
+                entry = get_irq_msi(irq);
                 write_msi_msg(irq, &entry->msg_save);
 
-                tail = msi_desc[irq]->link.tail;
+                tail = entry->link.tail;
                 irq = tail;
         }
 
@@ -451,7 +450,7 @@ static int msi_capability_init(struct pci_dev *dev)
         if (irq < 0)
                 return irq;
 
-        entry = get_irq_data(irq);
+        entry = get_irq_msi(irq);
         entry->link.head = irq;
         entry->link.tail = irq;
         entry->msi_attrib.type = PCI_CAP_ID_MSI;
@@ -486,7 +485,7 @@ static int msi_capability_init(struct pci_dev *dev)
         }
 
         dev->first_msi_irq = irq;
-        msi_desc[irq] = entry;
+        set_irq_msi(irq, entry);
         /* Set MSI enabled bits  */
         enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
 
@@ -535,7 +534,7 @@ static int msix_capability_init(struct pci_dev *dev,
                 if (irq < 0)
                         break;
 
-                entry = get_irq_data(irq);
+                entry = get_irq_msi(irq);
                 j = entries[i].entry;
                 entries[i].vector = irq;
                 entry->msi_attrib.type = PCI_CAP_ID_MSIX;
@@ -565,7 +564,7 @@ static int msix_capability_init(struct pci_dev *dev,
                         break;
                 }
 
-                msi_desc[irq] = entry;
+                set_irq_msi(irq, entry);
         }
         if (i != nvec) {
                 int avail = i - 1;
@@ -682,7 +681,7 @@ void pci_disable_msi(struct pci_dev* dev)
 
         disable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
 
-        entry = msi_desc[dev->first_msi_irq];
+        entry = get_irq_msi(dev->first_msi_irq);
         if (!entry || !entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) {
                 return;
         }
@@ -709,7 +708,7 @@ static int msi_free_irq(struct pci_dev* dev, int irq)
 
         arch_teardown_msi_irq(irq);
 
-        entry = msi_desc[irq];
+        entry = get_irq_msi(irq);
         if (!entry || entry->dev != dev) {
                 return -EINVAL;
         }
@@ -717,10 +716,9 @@ static int msi_free_irq(struct pci_dev* dev, int irq)
         entry_nr = entry->msi_attrib.entry_nr;
         head = entry->link.head;
         base = entry->mask_base;
-        msi_desc[entry->link.head]->link.tail = entry->link.tail;
-        msi_desc[entry->link.tail]->link.head = entry->link.head;
+        get_irq_msi(entry->link.head)->link.tail = entry->link.tail;
+        get_irq_msi(entry->link.tail)->link.head = entry->link.head;
         entry->dev = NULL;
-        msi_desc[irq] = NULL;
 
         destroy_msi_irq(irq);
 
@@ -821,7 +819,7 @@ void pci_disable_msix(struct pci_dev* dev)
 
         irq = head = dev->first_msi_irq;
         while (head != tail) {
-                tail = msi_desc[irq]->link.tail;
+                tail = get_irq_msi(irq)->link.tail;
                 if (irq_has_action(irq))
                         warning = 1;
                 else if (irq != head)   /* Release MSI-X irq */
@@ -867,8 +865,8 @@ void msi_remove_pci_irq_vectors(struct pci_dev* dev)
 
                 irq = head = dev->first_msi_irq;
                 while (head != tail) {
-                        tail = msi_desc[irq]->link.tail;
-                        base = msi_desc[irq]->mask_base;
+                        tail = get_irq_msi(irq)->link.tail;
+                        base = get_irq_msi(irq)->mask_base;
                         if (irq_has_action(irq))
                                 warning = 1;
                         else if (irq != head) /* Release MSI-X irq */
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 52fc4052a0ae..5504b671357f 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -68,6 +68,7 @@ typedef	void fastcall (*irq_flow_handler_t)(unsigned int irq,
 #define IRQ_MOVE_PENDING        0x40000000      /* need to re-target IRQ destination */
 
 struct proc_dir_entry;
+struct msi_desc;
 
 /**
  * struct irq_chip - hardware interrupt chip descriptor
@@ -148,6 +149,7 @@ struct irq_chip {
 struct irq_desc {
         irq_flow_handler_t      handle_irq;
         struct irq_chip         *chip;
+        struct msi_desc         *msi_desc;
         void                    *handler_data;
         void                    *chip_data;
         struct irqaction        *action;        /* IRQ action list */
@@ -373,10 +375,12 @@ extern int set_irq_chip(unsigned int irq, struct irq_chip *chip);
 extern int set_irq_data(unsigned int irq, void *data);
 extern int set_irq_chip_data(unsigned int irq, void *data);
 extern int set_irq_type(unsigned int irq, unsigned int type);
+extern int set_irq_msi(unsigned int irq, struct msi_desc *entry);
 
 #define get_irq_chip(irq)       (irq_desc[irq].chip)
 #define get_irq_chip_data(irq)  (irq_desc[irq].chip_data)
 #define get_irq_data(irq)       (irq_desc[irq].handler_data)
+#define get_irq_msi(irq)        (irq_desc[irq].msi_desc)
 
 #endif /* CONFIG_GENERIC_HARDIRQS */
 
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index d27b25855743..475e8a71bcdc 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -39,6 +39,7 @@ void dynamic_irq_init(unsigned int irq)
         desc->chip = &no_irq_chip;
         desc->handle_irq = handle_bad_irq;
         desc->depth = 1;
+        desc->msi_desc = NULL;
         desc->handler_data = NULL;
         desc->chip_data = NULL;
         desc->action = NULL;
@@ -74,6 +75,9 @@ void dynamic_irq_cleanup(unsigned int irq)
                 WARN_ON(1);
                 return;
         }
+        desc->msi_desc = NULL;
+        desc->handler_data = NULL;
+        desc->chip_data = NULL;
         desc->handle_irq = handle_bad_irq;
         desc->chip = &no_irq_chip;
         spin_unlock_irqrestore(&desc->lock, flags);
@@ -162,6 +166,30 @@ int set_irq_data(unsigned int irq, void *data)
 EXPORT_SYMBOL(set_irq_data);
 
 /**
+ *      set_irq_data - set irq type data for an irq
+ *      @irq:   Interrupt number
+ *      @data:  Pointer to interrupt specific data
+ *
+ *      Set the hardware irq controller data for an irq
+ */
+int set_irq_msi(unsigned int irq, struct msi_desc *entry)
+{
+        struct irq_desc *desc;
+        unsigned long flags;
+
+        if (irq >= NR_IRQS) {
+                printk(KERN_ERR
+                       "Trying to install msi data for IRQ%d\n", irq);
+                return -EINVAL;
+        }
+        desc = irq_desc + irq;
+        spin_lock_irqsave(&desc->lock, flags);
+        desc->msi_desc = entry;
+        spin_unlock_irqrestore(&desc->lock, flags);
+        return 0;
+}
+
+/**
  *      set_irq_chip_data - set irq chip data for an irq
  *      @irq:   Interrupt number
  *      @data:  Pointer to chip specific data