powerpc/fsl_msi: Handle msi-available-ranges better

Now handles multiple ranges, doesn't make assumptions about interrupt
specifier format, and doesn't claim interrupts that don't correspond to an
available range.

Also has some better error checking.

The device tree binding is updated to clarify some existing assumptions.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 56 insertions, 36 deletions

diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index f6051d7de3ed..8d6b074bb3e9 100644
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2007-2010 Freescale Semiconductor, Inc.
+ * Copyright (C) 2007-2011 Freescale Semiconductor, Inc.
  *
  * Author: Tony Li <tony.li@freescale.com>
  *         Jason Jin <Jason.jin@freescale.com>
@@ -274,19 +274,47 @@ static int fsl_of_msi_remove(struct platform_device *ofdev)
         return 0;
 }
 
+static int __devinit fsl_msi_setup_hwirq(struct fsl_msi *msi,
+                                         struct platform_device *dev,
+                                         int offset, int irq_index)
+{
+        struct fsl_msi_cascade_data *cascade_data = NULL;
+        int virt_msir;
+
+        virt_msir = irq_of_parse_and_map(dev->dev.of_node, irq_index);
+        if (virt_msir == NO_IRQ) {
+                dev_err(&dev->dev, "%s: Cannot translate IRQ index %d\n",
+                        __func__, irq_index);
+                return 0;
+        }
+
+        cascade_data = kzalloc(sizeof(struct fsl_msi_cascade_data), GFP_KERNEL);
+        if (!cascade_data) {
+                dev_err(&dev->dev, "No memory for MSI cascade data\n");
+                return -ENOMEM;
+        }
+
+        msi->msi_virqs[irq_index] = virt_msir;
+        cascade_data->index = offset + irq_index;
+        cascade_data->msi_data = msi;
+        set_irq_data(virt_msir, cascade_data);
+        set_irq_chained_handler(virt_msir, fsl_msi_cascade);
+
+        return 0;
+}
+
 static int __devinit fsl_of_msi_probe(struct platform_device *dev,
                                 const struct of_device_id *match)
 {
         struct fsl_msi *msi;
         struct resource res;
-        int err, i, count;
+        int err, i, j, irq_index, count;
         int rc;
-        int virt_msir;
         const u32 *p;
         struct fsl_msi_feature *features = match->data;
-        struct fsl_msi_cascade_data *cascade_data = NULL;
         int len;
         u32 offset;
+        static const u32 all_avail[] = { 0, NR_MSI_IRQS };
 
         printk(KERN_DEBUG "Setting up Freescale MSI support\n");
 
@@ -333,42 +361,34 @@ static int __devinit fsl_of_msi_probe(struct platform_device *dev,
                 goto error_out;
         }
 
-        p = of_get_property(dev->dev.of_node, "interrupts", &count);
-        if (!p) {
-                dev_err(&dev->dev, "no interrupts property found on %s\n",
-                                dev->dev.of_node->full_name);
-                err = -ENODEV;
-                goto error_out;
-        }
-        if (count % 8 != 0) {
-                dev_err(&dev->dev, "Malformed interrupts property on %s\n",
-                                dev->dev.of_node->full_name);
+        p = of_get_property(dev->dev.of_node, "msi-available-ranges", &len);
+        if (p && len % (2 * sizeof(u32)) != 0) {
+                dev_err(&dev->dev, "%s: Malformed msi-available-ranges property\n",
+                        __func__);
                 err = -EINVAL;
                 goto error_out;
         }
-        offset = 0;
-        p = of_get_property(dev->dev.of_node, "msi-available-ranges", &len);
-        if (p)
-                offset = *p / IRQS_PER_MSI_REG;
-
-        count /= sizeof(u32);
-        for (i = 0; i < min(count / 2, NR_MSI_REG); i++) {
-                virt_msir = irq_of_parse_and_map(dev->dev.of_node, i);
-                if (virt_msir != NO_IRQ) {
-                        cascade_data = kzalloc(
-                                        sizeof(struct fsl_msi_cascade_data),
-                                        GFP_KERNEL);
-                        if (!cascade_data) {
-                                dev_err(&dev->dev,
-                                        "No memory for MSI cascade data\n");
-                                err = -ENOMEM;
+
+        if (!p)
+                p = all_avail;
+
+        for (irq_index = 0, i = 0; i < len / (2 * sizeof(u32)); i++) {
+                if (p[i * 2] % IRQS_PER_MSI_REG ||
+                    p[i * 2 + 1] % IRQS_PER_MSI_REG) {
+                        printk(KERN_WARNING "%s: %s: msi available range of %u at %u is not IRQ-aligned\n",
+                               __func__, dev->dev.of_node->full_name,
+                               p[i * 2 + 1], p[i * 2]);
+                        err = -EINVAL;
+                        goto error_out;
+                }
+
+                offset = p[i * 2] / IRQS_PER_MSI_REG;
+                count = p[i * 2 + 1] / IRQS_PER_MSI_REG;
+
+                for (j = 0; j < count; j++, irq_index++) {
+                        err = fsl_msi_setup_hwirq(msi, dev, offset, irq_index);
+                        if (err)
                                 goto error_out;
-                        }
-                        msi->msi_virqs[i] = virt_msir;
-                        cascade_data->index = i + offset;
-                        cascade_data->msi_data = msi;
-                        set_irq_data(virt_msir, (void *)cascade_data);
-                        set_irq_chained_handler(virt_msir, fsl_msi_cascade);
                 }
         }