pcmcia: setup IRQ to be used by PCMCIA drivers at card insert

Setup the IRQ to be used by PCMCIA drivers already during the device
registration stage, making use of a new function pcmcia_setup_irq().
This will allow us to get rid of quite a lot of indirection in the
future.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

1 files changed, 124 insertions, 90 deletions

diff --git a/drivers/pcmcia/pcmcia_resource.c b/drivers/pcmcia/pcmcia_resource.c
index ba82cb3b1944..ff9c0bcb7e3a 100644
--- a/drivers/pcmcia/pcmcia_resource.c
+++ b/drivers/pcmcia/pcmcia_resource.c
@@ -23,6 +23,8 @@
 #include <linux/netdevice.h>
 #include <linux/slab.h>
 
+#include <asm/irq.h>
+
 #include <pcmcia/cs_types.h>
 #include <pcmcia/ss.h>
 #include <pcmcia/cs.h>
@@ -38,12 +40,6 @@ static int io_speed;
 module_param(io_speed, int, 0444);
 
 
-#ifdef CONFIG_PCMCIA_PROBE
-#include <asm/irq.h>
-/* mask of IRQs already reserved by other cards, we should avoid using them */
-static u8 pcmcia_used_irq[NR_IRQS];
-#endif
-
 static int pcmcia_adjust_io_region(struct resource *res, unsigned long start,
                                    unsigned long end, struct pcmcia_socket *s)
 {
@@ -440,15 +436,11 @@ static int pcmcia_release_irq(struct pcmcia_device *p_dev, irq_req_t *req)
         }
         if (--s->irq.Config == 0) {
                 c->state &= ~CONFIG_IRQ_REQ;
-                s->irq.AssignedIRQ = 0;
         }
 
         if (req->Handler)
                 free_irq(req->AssignedIRQ, p_dev->priv);
 
-#ifdef CONFIG_PCMCIA_PROBE
-        pcmcia_used_irq[req->AssignedIRQ]--;
-#endif
         ret = 0;
 
 out:
@@ -699,26 +691,14 @@ EXPORT_SYMBOL(pcmcia_request_io);
 /** pcmcia_request_irq
  *
  * Request_irq() reserves an irq for this client.
- *
- * Also, since Linux only reserves irq's when they are actually
- * hooked, we don't guarantee that an irq will still be available
- * when the configuration is locked.  Now that I think about it,
- * there might be a way to fix this using a dummy handler.
  */
 
-#ifdef CONFIG_PCMCIA_PROBE
-static irqreturn_t test_action(int cpl, void *dev_id)
-{
-        return IRQ_NONE;
-}
-#endif
-
 int pcmcia_request_irq(struct pcmcia_device *p_dev, irq_req_t *req)
 {
         struct pcmcia_socket *s = p_dev->socket;
         config_t *c;
-        int ret = -EINVAL, irq = 0;
-        int type;
+        int ret = -EINVAL, irq = p_dev->irq_v;
+        int type = IRQF_SHARED;
 
         mutex_lock(&s->ops_mutex);
 
@@ -736,63 +716,20 @@ int pcmcia_request_irq(struct pcmcia_device *p_dev, irq_req_t *req)
                 goto out;
         }
 
-        /* Decide what type of interrupt we are registering */
-        type = 0;
-        if (s->functions > 1)           /* All of this ought to be handled higher up */
-                type = IRQF_SHARED;
-        else if (req->Attributes & IRQ_TYPE_DYNAMIC_SHARING)
-                type = IRQF_SHARED;
-        else
-                printk(KERN_WARNING "pcmcia: Driver needs updating to support IRQ sharing.\n");
-
-        /* If the interrupt is already assigned, it must be the same */
-        if (s->irq.AssignedIRQ != 0)
-                irq = s->irq.AssignedIRQ;
-
-#ifdef CONFIG_PCMCIA_PROBE
         if (!irq) {
-                int try;
-                u32 mask = s->irq_mask;
-                void *data = p_dev; /* something unique to this device */
-
-                for (try = 0; try < 64; try++) {
-                        irq = try % 32;
-
-                        /* marked as available by driver, and not blocked by userspace? */
-                        if (!((mask >> irq) & 1))
-                                continue;
-
-                        /* avoid an IRQ which is already used by a PCMCIA card */
-                        if ((try < 32) && pcmcia_used_irq[irq])
-                                continue;
-
-                        /* register the correct driver, if possible, of check whether
-                         * registering a dummy handle works, i.e. if the IRQ isn't
-                         * marked as used by the kernel resource management core */
-                        ret = request_irq(irq,
-                                          (req->Handler) ? req->Handler : test_action,
-                                          type,
-                                          p_dev->devname,
-                                          (req->Handler) ? p_dev->priv : data);
-                        if (!ret) {
-                                if (!req->Handler)
-                                        free_irq(irq, data);
-                                break;
-                        }
-                }
+                dev_dbg(&s->dev, "no IRQ available\n");
+                goto out;
         }
-#endif
-        /* only assign PCI irq if no IRQ already assigned */
-        if (ret && !s->irq.AssignedIRQ) {
-                if (!s->pci_irq) {
-                        dev_printk(KERN_INFO, &s->dev, "no IRQ found\n");
-                        goto out;
-                }
-                type = IRQF_SHARED;
-                irq = s->pci_irq;
+
+        if (!(req->Attributes & IRQ_TYPE_DYNAMIC_SHARING)) {
+                req->Attributes |= IRQ_TYPE_DYNAMIC_SHARING;
+                dev_printk(KERN_WARNING, &p_dev->dev, "pcmcia: "
+                        "request for exclusive IRQ could not be fulfilled.\n");
+                dev_printk(KERN_WARNING, &p_dev->dev, "pcmcia: the driver "
+                        "needs updating to supported shared IRQ lines.\n");
         }
 
-        if (ret && req->Handler) {
+        if (req->Handler) {
                 ret = request_irq(irq, req->Handler, type,
                                   p_dev->devname, p_dev->priv);
                 if (ret) {
@@ -802,25 +739,13 @@ int pcmcia_request_irq(struct pcmcia_device *p_dev, irq_req_t *req)
                 }
         }
 
-        /* Make sure the fact the request type was overridden is passed back */
-        if (type == IRQF_SHARED && !(req->Attributes & IRQ_TYPE_DYNAMIC_SHARING)) {
-                req->Attributes |= IRQ_TYPE_DYNAMIC_SHARING;
-                dev_printk(KERN_WARNING, &p_dev->dev, "pcmcia: "
-                        "request for exclusive IRQ could not be fulfilled.\n");
-                dev_printk(KERN_WARNING, &p_dev->dev, "pcmcia: the driver "
-                        "needs updating to supported shared IRQ lines.\n");
-        }
         c->irq.Attributes = req->Attributes;
-        s->irq.AssignedIRQ = req->AssignedIRQ = irq;
+        req->AssignedIRQ = irq;
         s->irq.Config++;
 
         c->state |= CONFIG_IRQ_REQ;
         p_dev->_irq = 1;
 
-#ifdef CONFIG_PCMCIA_PROBE
-        pcmcia_used_irq[irq]++;
-#endif
-
         ret = 0;
 out:
         mutex_unlock(&s->ops_mutex);
@@ -829,6 +754,115 @@ out:
 EXPORT_SYMBOL(pcmcia_request_irq);
 
 
+#ifdef CONFIG_PCMCIA_PROBE
+
+/* mask of IRQs already reserved by other cards, we should avoid using them */
+static u8 pcmcia_used_irq[NR_IRQS];
+
+static irqreturn_t test_action(int cpl, void *dev_id)
+{
+        return IRQ_NONE;
+}
+
+/**
+ * pcmcia_setup_isa_irq() - determine whether an ISA IRQ can be used
+ * @p_dev - the associated PCMCIA device
+ *
+ * locking note: must be called with ops_mutex locked.
+ */
+static int pcmcia_setup_isa_irq(struct pcmcia_device *p_dev, int type)
+{
+        struct pcmcia_socket *s = p_dev->socket;
+        unsigned int try, irq;
+        u32 mask = s->irq_mask;
+        int ret = -ENODEV;
+
+        for (try = 0; try < 64; try++) {
+                irq = try % 32;
+
+                /* marked as available by driver, not blocked by userspace? */
+                if (!((mask >> irq) & 1))
+                        continue;
+
+                /* avoid an IRQ which is already used by another PCMCIA card */
+                if ((try < 32) && pcmcia_used_irq[irq])
+                        continue;
+
+                /* register the correct driver, if possible, to check whether
+                 * registering a dummy handle works, i.e. if the IRQ isn't
+                 * marked as used by the kernel resource management core */
+                ret = request_irq(irq, test_action, type, p_dev->devname,
+                                  p_dev);
+                if (!ret) {
+                        free_irq(irq, p_dev);
+                        p_dev->irq_v = s->irq.AssignedIRQ = irq;
+                        pcmcia_used_irq[irq]++;
+                        break;
+                }
+        }
+
+        return ret;
+}
+
+void pcmcia_cleanup_irq(struct pcmcia_socket *s)
+{
+        pcmcia_used_irq[s->irq.AssignedIRQ]--;
+        s->irq.AssignedIRQ = 0;
+}
+
+#else /* CONFIG_PCMCIA_PROBE */
+
+static int pcmcia_setup_isa_irq(struct pcmcia_device *p_dev, int type)
+{
+        return -EINVAL;
+}
+
+void pcmcia_cleanup_irq(struct pcmcia_socket *s)
+{
+        s->irq.AssignedIRQ = 0;
+        return;
+}
+
+#endif  /* CONFIG_PCMCIA_PROBE */
+
+
+/**
+ * pcmcia_setup_irq() - determine IRQ to be used for device
+ * @p_dev - the associated PCMCIA device
+ *
+ * locking note: must be called with ops_mutex locked.
+ */
+int pcmcia_setup_irq(struct pcmcia_device *p_dev)
+{
+        struct pcmcia_socket *s = p_dev->socket;
+
+        if (p_dev->irq_v)
+                return 0;
+
+        /* already assigned? */
+        if (s->irq.AssignedIRQ) {
+                p_dev->irq_v = s->irq.AssignedIRQ;
+                return 0;
+        }
+
+        /* prefer an exclusive ISA irq */
+        if (!pcmcia_setup_isa_irq(p_dev, 0))
+                return 0;
+
+        /* but accept a shared ISA irq */
+        if (!pcmcia_setup_isa_irq(p_dev, IRQF_SHARED))
+                return 0;
+
+        /* but use the PCI irq otherwise */
+        if (s->pci_irq) {
+                p_dev->irq_v = s->irq.AssignedIRQ = s->pci_irq;
+                return 0;
+        }
+
+        return -EINVAL;
+}
+
+
 /** pcmcia_request_window
  *
  * Request_window() establishes a mapping between card memory space