[POWERPC] Use 1TB segments

This makes the kernel use 1TB segments for all kernel mappings and for
user addresses of 1TB and above, on machines which support them
(currently POWER5+, POWER6 and PA6T).

We detect that the machine supports 1TB segments by looking at the
ibm,processor-segment-sizes property in the device tree.

We don't currently use 1TB segments for user addresses < 1T, since
that would effectively prevent 32-bit processes from using huge pages
unless we also had a way to revert to using 256MB segments.  That
would be possible but would involve extra complications (such as
keeping track of which segment size was used when HPTEs were inserted)
and is not addressed here.

Parts of this patch were originally written by Ben Herrenschmidt.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 8 insertions, 6 deletions

diff --git a/arch/powerpc/platforms/ps3/htab.c b/arch/powerpc/platforms/ps3/htab.c
index 5d2e176a1b18..7382f195c4f8 100644
--- a/arch/powerpc/platforms/ps3/htab.c
+++ b/arch/powerpc/platforms/ps3/htab.c
@@ -60,7 +60,8 @@ static void _debug_dump_hpte(unsigned long pa, unsigned long va,
 }
 
 static long ps3_hpte_insert(unsigned long hpte_group, unsigned long va,
-	unsigned long pa, unsigned long rflags, unsigned long vflags, int psize)
+	unsigned long pa, unsigned long rflags, unsigned long vflags,
+	int psize, int ssize)
 {
 	unsigned long slot;
 	struct hash_pte lhpte;
@@ -72,7 +73,8 @@ static long ps3_hpte_insert(unsigned long hpte_group, unsigned long va,
 
 	vflags &= ~HPTE_V_SECONDARY; /* this bit is ignored */
 
-	lhpte.v = hpte_encode_v(va, psize) | vflags | HPTE_V_VALID;
+	lhpte.v = hpte_encode_v(va, psize, MMU_SEGSIZE_256M) |
+		vflags | HPTE_V_VALID;
 	lhpte.r = hpte_encode_r(ps3_mm_phys_to_lpar(pa), psize) | rflags;
 
 	p_pteg = hpte_group / HPTES_PER_GROUP;
@@ -167,14 +169,14 @@ static long ps3_hpte_remove(unsigned long hpte_group)
 }
 
 static long ps3_hpte_updatepp(unsigned long slot, unsigned long newpp,
-	unsigned long va, int psize, int local)
+	unsigned long va, int psize, int ssize, int local)
 {
 	unsigned long flags;
 	unsigned long result;
 	unsigned long pteg, bit;
 	unsigned long hpte_v, want_v;
 
-	want_v = hpte_encode_v(va, psize);
+	want_v = hpte_encode_v(va, psize, MMU_SEGSIZE_256M);
 
 	spin_lock_irqsave(&ps3_bolttab_lock, flags);
 
@@ -205,13 +207,13 @@ static long ps3_hpte_updatepp(unsigned long slot, unsigned long newpp,
 }
 
 static void ps3_hpte_updateboltedpp(unsigned long newpp, unsigned long ea,
-	int psize)
+	int psize, int ssize)
 {
 	panic("ps3_hpte_updateboltedpp() not implemented");
 }
 
 static void ps3_hpte_invalidate(unsigned long slot, unsigned long va,
-	int psize, int local)
+	int psize, int ssize, int local)
 {
 	unsigned long flags;
 	unsigned long result;