[PATCH] ppc64: support 64k pages

Adds a new CONFIG_PPC_64K_PAGES which, when enabled, changes the kernel
base page size to 64K.  The resulting kernel still boots on any
hardware.  On current machines with 4K pages support only, the kernel
will maintain 16 "subpages" for each 64K page transparently.

Note that while real 64K capable HW has been tested, the current patch
will not enable it yet as such hardware is not released yet, and I'm
still verifying with the firmware architects the proper to get the
information from the newer hypervisors.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/powerpc/lib/copyuser_64.S b/arch/powerpc/lib/copyuser_64.S
index a0b3fbb..6d69ef3 100644
--- a/arch/powerpc/lib/copyuser_64.S
+++ b/arch/powerpc/lib/copyuser_64.S
@@ -24,7 +24,7 @@
 	std	r4,-16(r1)
 	std	r5,-8(r1)
 	dcbt	0,r4
-	beq	.Lcopy_page
+	beq	.Lcopy_page_4K
 	andi.	r6,r6,7
 	mtcrf	0x01,r5
 	blt	cr1,.Lshort_copy
@@ -366,7 +366,7 @@
  * above (following the .Ldst_aligned label) but it runs slightly
  * slower on POWER3.
  */
-.Lcopy_page:
+.Lcopy_page_4K:
 	std	r31,-32(1)
 	std	r30,-40(1)
 	std	r29,-48(1)