[Xen-devel] [PATCH 1/5] xen: events: use irq_alloc_desc(_at) instead of open-coding an IRQ allocator.

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

Encapsulate allocate and free in xen_irq_alloc and xen_irq_free.

Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
 drivers/xen/events.c |   68 ++++++++++++++++++++-----------------------------
 1 files changed, 28 insertions(+), 40 deletions(-)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 97612f5..c8f3e43 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -394,41 +394,29 @@ static int find_unbound_pirq(void)
        return -1;
 }
 
-static int find_unbound_irq(void)
+static int xen_irq_alloc(void)
 {
-       struct irq_data *data;
-       int irq, res;
-       int start = get_nr_hw_irqs();
+       int irq = irq_alloc_desc(0);
 
-       if (start == nr_irqs)
-               goto no_irqs;
-
-       /* nr_irqs is a magic value. Must not use it.*/
-       for (irq = nr_irqs-1; irq > start; irq--) {
-               data = irq_get_irq_data(irq);
-               /* only 0->15 have init'd desc; handle irq > 16 */
-               if (!data)
-                       break;
-               if (data->chip == &no_irq_chip)
-                       break;
-               if (data->chip != &xen_dynamic_chip)
-                       continue;
-               if (irq_info[irq].type == IRQT_UNBOUND)
-                       return irq;
-       }
-
-       if (irq == start)
-               goto no_irqs;
+       if (irq < 0)
+               panic("No available IRQ to bind to: increase nr_irqs!\n");
 
-       res = irq_alloc_desc_at(irq, 0);
+       return irq;
+}
 
-       if (WARN_ON(res != irq))
-               return -1;
+static void xen_irq_alloc_specific(unsigned irq)
+{
+       int res = irq_alloc_desc_at(irq, 0);
 
-       return irq;
+       if (res < 0)
+               panic("No available IRQ: increase nr_irqs!\n");
+       if (res != irq)
+               panic("Unable to allocate to IRQ%d\n", irq);
+}
 
-no_irqs:
-       panic("No available IRQ to bind to: increase nr_irqs!\n");
+static void xen_irq_free(unsigned irq)
+{
+       irq_free_desc(irq);
 }
 
 static bool identity_mapped_irq(unsigned irq)
@@ -627,9 +615,9 @@ int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int 
shareable, char *name)
        if (identity_mapped_irq(gsi) || (!xen_initial_domain() &&
                                xen_pv_domain())) {
                irq = gsi;
-               irq_alloc_desc_at(irq, 0);
+               xen_irq_alloc_specific(irq);
        } else
-               irq = find_unbound_irq();
+               irq = xen_irq_alloc();
 
        set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
                                      handle_level_irq, name);
@@ -642,7 +630,7 @@ int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int 
shareable, char *name)
         * this in the priv domain. */
        if (xen_initial_domain() &&
            HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
-               irq_free_desc(irq);
+               xen_irq_free(irq);
                irq = -ENOSPC;
                goto out;
        }
@@ -665,7 +653,7 @@ void xen_allocate_pirq_msi(char *name, int *irq, int *pirq)
 {
        spin_lock(&irq_mapping_update_lock);
 
-       *irq = find_unbound_irq();
+       *irq = xen_irq_alloc();
        if (*irq == -1)
                goto out;
 
@@ -712,7 +700,7 @@ int xen_create_msi_irq(struct pci_dev *dev, struct msi_desc 
*msidesc, int type)
 
        spin_lock(&irq_mapping_update_lock);
 
-       irq = find_unbound_irq();
+       irq = xen_irq_alloc();
 
        if (irq == -1)
                goto out;
@@ -721,7 +709,7 @@ int xen_create_msi_irq(struct pci_dev *dev, struct msi_desc 
*msidesc, int type)
        if (rc) {
                printk(KERN_WARNING "xen map irq failed %d\n", rc);
 
-               irq_free_desc(irq);
+               xen_irq_free(irq);
 
                irq = -1;
                goto out;
@@ -762,7 +750,7 @@ int xen_destroy_irq(int irq)
        }
        irq_info[irq] = mk_unbound_info();
 
-       irq_free_desc(irq);
+       xen_irq_free(irq);
 
 out:
        spin_unlock(&irq_mapping_update_lock);
@@ -788,7 +776,7 @@ int bind_evtchn_to_irq(unsigned int evtchn)
        irq = evtchn_to_irq[evtchn];
 
        if (irq == -1) {
-               irq = find_unbound_irq();
+               irq = xen_irq_alloc();
 
                set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
                                              handle_fasteoi_irq, "event");
@@ -813,7 +801,7 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int 
cpu)
        irq = per_cpu(ipi_to_irq, cpu)[ipi];
 
        if (irq == -1) {
-               irq = find_unbound_irq();
+               irq = xen_irq_alloc();
                if (irq < 0)
                        goto out;
 
@@ -849,7 +837,7 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
        irq = per_cpu(virq_to_irq, cpu)[virq];
 
        if (irq == -1) {
-               irq = find_unbound_irq();
+               irq = xen_irq_alloc();
 
                set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
                                              handle_percpu_irq, "virq");
@@ -908,7 +896,7 @@ static void unbind_from_irq(unsigned int irq)
        if (irq_info[irq].type != IRQT_UNBOUND) {
                irq_info[irq] = mk_unbound_info();
 
-               irq_free_desc(irq);
+               xen_irq_free(irq);
        }
 
        spin_unlock(&irq_mapping_update_lock);
-- 
1.5.6.5


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel