Merge branch 'master'

1 files changed, 46 insertions, 5 deletions

diff --git a/arch/sparc64/kernel/prom.c b/arch/sparc64/kernel/prom.c
index 99daeee4209d..c86007a2aa3f 100644
--- a/arch/sparc64/kernel/prom.c
+++ b/arch/sparc64/kernel/prom.c
@@ -539,6 +539,45 @@ static unsigned long __sabre_onboard_imap_off[] = {
         ((ino & 0x20) ? (SABRE_ICLR_SCSI + (((ino) & 0x1f) << 3)) :  \
                         (SABRE_ICLR_A_SLOT0 + (((ino) & 0x1f)<<3)))
 
+static int sabre_device_needs_wsync(struct device_node *dp)
+{
+        struct device_node *parent = dp->parent;
+        char *parent_model, *parent_compat;
+
+        /* This traversal up towards the root is meant to
+         * handle two cases:
+         *
+         * 1) non-PCI bus sitting under PCI, such as 'ebus'
+         * 2) the PCI controller interrupts themselves, which
+         *    will use the sabre_irq_build but do not need
+         *    the DMA synchronization handling
+         */
+        while (parent) {
+                if (!strcmp(parent->type, "pci"))
+                        break;
+                parent = parent->parent;
+        }
+
+        if (!parent)
+                return 0;
+
+        parent_model = of_get_property(parent,
+                                       "model", NULL);
+        if (parent_model &&
+            (!strcmp(parent_model, "SUNW,sabre") ||
+             !strcmp(parent_model, "SUNW,simba")))
+                return 0;
+
+        parent_compat = of_get_property(parent,
+                                        "compatible", NULL);
+        if (parent_compat &&
+            (!strcmp(parent_compat, "pci108e,a000") ||
+             !strcmp(parent_compat, "pci108e,a001")))
+                return 0;
+
+        return 1;
+}
+
 static unsigned int sabre_irq_build(struct device_node *dp,
                                     unsigned int ino,
                                     void *_data)
@@ -577,15 +616,17 @@ static unsigned int sabre_irq_build(struct device_node *dp,
 
         virt_irq = build_irq(inofixup, iclr, imap);
 
+        /* If the parent device is a PCI<->PCI bridge other than
+         * APB, we have to install a pre-handler to ensure that
+         * all pending DMA is drained before the interrupt handler
+         * is run.
+         */
         regs = of_get_property(dp, "reg", NULL);
-        if (regs &&
-            ((regs->phys_hi >> 16) & 0xff) != irq_data->pci_first_busno) {
+        if (regs && sabre_device_needs_wsync(dp)) {
                 irq_install_pre_handler(virt_irq,
                                         sabre_wsync_handler,
                                         (void *) (long) regs->phys_hi,
-                                        (void *)
-                                        controller_regs +
-                                        SABRE_WRSYNC);
+                                        (void *) irq_data);
         }
 
         return virt_irq;