[POWERPC] cell: add RAS support

This is a first version of support for the Cell BE "Reliability,
Availability and Serviceability" features.

It doesn't yet handle some of the RAS interrupts (the ones described in
iic_is/iic_irr), I'm still working on a proper way to expose these. They
are essentially a cascaded controller by themselves (sic !) though I may
just handle them locally to the iic driver. I need also to sync with
David Erb on the way he hooked in the performance monitor interrupt.

So that's all for 2.6.17 and I'll do more work on that with my rework of
the powerpc interrupt layer that I'm hacking on at the moment.

Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 43 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 629023240ece..483455c5bb02 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -2105,3 +2105,46 @@ int prom_update_property(struct device_node *np,
         return 0;
 }
 
+
+/* Find the device node for a given logical cpu number, also returns the cpu
+ * local thread number (index in ibm,interrupt-server#s) if relevant and
+ * asked for (non NULL)
+ */
+struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
+{
+        int hardid;
+        struct device_node *np;
+
+        hardid = get_hard_smp_processor_id(cpu);
+
+        for_each_node_by_type(np, "cpu") {
+                u32 *intserv;
+                unsigned int plen, t;
+
+                /* Check for ibm,ppc-interrupt-server#s. If it doesn't exist
+                 * fallback to "reg" property and assume no threads
+                 */
+                intserv = (u32 *)get_property(np, "ibm,ppc-interrupt-server#s",
+                                              &plen);
+                if (intserv == NULL) {
+                        u32 *reg = (u32 *)get_property(np, "reg", NULL);
+                        if (reg == NULL)
+                                continue;
+                        if (*reg == hardid) {
+                                if (thread)
+                                        *thread = 0;
+                                return np;
+                        }
+                } else {
+                        plen /= sizeof(u32);
+                        for (t = 0; t < plen; t++) {
+                                if (hardid == intserv[t]) {
+                                        if (thread)
+                                                *thread = t;
+                                        return np;
+                                }
+                        }
+                }
+        }
+        return NULL;
+}