[SPARC64]: Refine Sabre wsync logic.

It is only needed when there is a PCI-PCI bridge sitting
between the device and the PCI host controller which is
not a Simba APB bridge.

Add logic to handle two special cases:

1) device behind EBUS, which sits on PCI
2) PCI controller interrupts

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/arch/sparc64/kernel/prom.c b/arch/sparc64/kernel/prom.c
index 86cdbd4dbad576af598c7d96a0c592ea9045683b..c86007a2aa3f251493606edb38a37edea7298b0d 100644 (file)
--- a/arch/sparc64/kernel/prom.c
+++ b/arch/sparc64/kernel/prom.c
@@ -539,23 +539,43 @@ static unsigned long __sabre_onboard_imap_off[] = {
        ((ino & 0x20) ? (SABRE_ICLR_SCSI + (((ino) & 0x1f) << 3)) :  \
                        (SABRE_ICLR_A_SLOT0 + (((ino) & 0x1f)<<3)))
 
-static int parent_is_sabre_or_simba(struct device_node *dp)
+static int sabre_device_needs_wsync(struct device_node *dp)
 {
+       struct device_node *parent = dp->parent;
        char *parent_model, *parent_compat;
 
-       parent_model = of_get_property(dp->parent, "model", NULL);
+       /* 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 1;
+               return 0;
 
-       parent_compat = of_get_property(dp->parent, "compatible", NULL);
+       parent_compat = of_get_property(parent,
+                                       "compatible", NULL);
        if (parent_compat &&
            (!strcmp(parent_compat, "pci108e,a000") ||
             !strcmp(parent_compat, "pci108e,a001")))
-               return 1;
+               return 0;
 
-       return 0;
+       return 1;
 }
 
 static unsigned int sabre_irq_build(struct device_node *dp,
@@ -602,8 +622,7 @@ static unsigned int sabre_irq_build(struct device_node *dp,
         * is run.
         */
        regs = of_get_property(dp, "reg", NULL);
-       if (regs &&
-           !parent_is_sabre_or_simba(dp)) {
+       if (regs && sabre_device_needs_wsync(dp)) {
                irq_install_pre_handler(virt_irq,
                                        sabre_wsync_handler,
                                        (void *) (long) regs->phys_hi,