sparc64: Probe cpu page size support more portably.

On sun4v, interrogate the machine description.  This code is extremely
defensive in nature, and a lot of the checks can probably be removed.

On sun4u things are a lot simpler.  There are the page sizes all chips
support, and then Panther adds 32MB and 256MB pages.

Report the probed value in /proc/cpuinfo

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

1 files changed, 24 insertions, 0 deletions

diff --git a/arch/sparc/kernel/mdesc.c b/arch/sparc/kernel/mdesc.c
index 6dc796280589..831c001604e8 100644
--- a/arch/sparc/kernel/mdesc.c
+++ b/arch/sparc/kernel/mdesc.c
@@ -817,6 +817,30 @@ void __cpuinit mdesc_populate_present_mask(cpumask_t *mask)
         mdesc_iterate_over_cpus(record_one_cpu, NULL, mask);
 }
 
+static void * __init check_one_pgsz(struct mdesc_handle *hp, u64 mp, int cpuid, void *arg)
+{
+        const u64 *pgsz_prop = mdesc_get_property(hp, mp, "mmu-page-size-list", NULL);
+        unsigned long *pgsz_mask = arg;
+        u64 val;
+
+        val = (HV_PGSZ_MASK_8K | HV_PGSZ_MASK_64K |
+               HV_PGSZ_MASK_512K | HV_PGSZ_MASK_4MB);
+        if (pgsz_prop)
+                val = *pgsz_prop;
+
+        if (!*pgsz_mask)
+                *pgsz_mask = val;
+        else
+                *pgsz_mask &= val;
+        return NULL;
+}
+
+void __init mdesc_get_page_sizes(cpumask_t *mask, unsigned long *pgsz_mask)
+{
+        *pgsz_mask = 0;
+        mdesc_iterate_over_cpus(check_one_pgsz, pgsz_mask, mask);
+}
+
 static void * __cpuinit fill_in_one_cpu(struct mdesc_handle *hp, u64 mp, int cpuid, void *arg)
 {
         const u64 *cfreq = mdesc_get_property(hp, mp, "clock-frequency", NULL);