[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>

1 files changed, 31 insertions, 34 deletions

diff --git a/arch/powerpc/platforms/iseries/htab.c b/arch/powerpc/platforms/iseries/htab.c
index b3c6c3374ca60..30bdcf3925d9b 100644
--- a/arch/powerpc/platforms/iseries/htab.c
+++ b/arch/powerpc/platforms/iseries/htab.c
@@ -39,15 +39,16 @@ static inline void iSeries_hunlock(unsigned long slot)
 	spin_unlock(&iSeries_hlocks[(slot >> 4) & 0x3f]);
 }
 
-static long iSeries_hpte_insert(unsigned long hpte_group, unsigned long va,
-				unsigned long prpn, unsigned long vflags,
-				unsigned long rflags)
+long iSeries_hpte_insert(unsigned long hpte_group, unsigned long va,
+			 unsigned long pa, unsigned long rflags,
+			 unsigned long vflags, int psize)
 {
-	unsigned long arpn;
 	long slot;
 	hpte_t lhpte;
 	int secondary = 0;
 
+	BUG_ON(psize != MMU_PAGE_4K);
+
 	/*
 	 * The hypervisor tries both primary and secondary.
 	 * If we are being called to insert in the secondary,
@@ -59,8 +60,19 @@ static long iSeries_hpte_insert(unsigned long hpte_group, unsigned long va,
 
 	iSeries_hlock(hpte_group);
 
-	slot = HvCallHpt_findValid(&lhpte, va >> PAGE_SHIFT);
-	BUG_ON(lhpte.v & HPTE_V_VALID);
+	slot = HvCallHpt_findValid(&lhpte, va >> HW_PAGE_SHIFT);
+	if (unlikely(lhpte.v & HPTE_V_VALID)) {
+		if (vflags & HPTE_V_BOLTED) {
+			HvCallHpt_setSwBits(slot, 0x10, 0);
+			HvCallHpt_setPp(slot, PP_RWXX);
+			iSeries_hunlock(hpte_group);
+			if (slot < 0)
+				return 0x8 | (slot & 7);
+			else
+				return slot & 7;
+		}
+		BUG();
+	}
 
 	if (slot == -1)	{ /* No available entry found in either group */
 		iSeries_hunlock(hpte_group);
@@ -73,10 +85,9 @@ static long iSeries_hpte_insert(unsigned long hpte_group, unsigned long va,
 		slot &= 0x7fffffffffffffff;
 	}
 
-	arpn = phys_to_abs(prpn << PAGE_SHIFT) >> PAGE_SHIFT;
 
-	lhpte.v = (va >> 23) << HPTE_V_AVPN_SHIFT | vflags | HPTE_V_VALID;
-	lhpte.r = (arpn << HPTE_R_RPN_SHIFT) | rflags;
+ 	lhpte.v = hpte_encode_v(va, MMU_PAGE_4K) | vflags | HPTE_V_VALID;
+	lhpte.r = hpte_encode_r(phys_to_abs(pa), MMU_PAGE_4K) | rflags;
 
 	/* Now fill in the actual HPTE */
 	HvCallHpt_addValidate(slot, secondary, &lhpte);
@@ -86,25 +97,6 @@ static long iSeries_hpte_insert(unsigned long hpte_group, unsigned long va,
 	return (secondary << 3) | (slot & 7);
 }
 
-long iSeries_hpte_bolt_or_insert(unsigned long hpte_group,
-		unsigned long va, unsigned long prpn, unsigned long vflags,
-		unsigned long rflags)
-{
-	long slot;
-	hpte_t lhpte;
-
-	slot = HvCallHpt_findValid(&lhpte, va >> PAGE_SHIFT);
-
-	if (lhpte.v & HPTE_V_VALID) {
-		/* Bolt the existing HPTE */
-		HvCallHpt_setSwBits(slot, 0x10, 0);
-		HvCallHpt_setPp(slot, PP_RWXX);
-		return 0;
-	}
-
-	return iSeries_hpte_insert(hpte_group, va, prpn, vflags, rflags);
-}
-
 static unsigned long iSeries_hpte_getword0(unsigned long slot)
 {
 	hpte_t hpte;
@@ -150,15 +142,17 @@ static long iSeries_hpte_remove(unsigned long hpte_group)
  *	bits 61..63 : PP2,PP1,PP0
  */
 static long iSeries_hpte_updatepp(unsigned long slot, unsigned long newpp,
-				  unsigned long va, int large, int local)
+				  unsigned long va, int psize, int local)
 {
 	hpte_t hpte;
-	unsigned long avpn = va >> 23;
+	unsigned long want_v;
 
 	iSeries_hlock(slot);
 
 	HvCallHpt_get(&hpte, slot);
-	if ((HPTE_V_AVPN_VAL(hpte.v) == avpn) && (hpte.v & HPTE_V_VALID)) {
+	want_v = hpte_encode_v(va, MMU_PAGE_4K);
+
+	if (HPTE_V_COMPARE(hpte.v, want_v) && (hpte.v & HPTE_V_VALID)) {
 		/*
 		 * Hypervisor expects bits as NPPP, which is
 		 * different from how they are mapped in our PP.
@@ -210,14 +204,17 @@ static long iSeries_hpte_find(unsigned long vpn)
  *
  * No need to lock here because we should be the only user.
  */
-static void iSeries_hpte_updateboltedpp(unsigned long newpp, unsigned long ea)
+static void iSeries_hpte_updateboltedpp(unsigned long newpp, unsigned long ea,
+					int psize)
 {
 	unsigned long vsid,va,vpn;
 	long slot;
 
+	BUG_ON(psize != MMU_PAGE_4K);
+
 	vsid = get_kernel_vsid(ea);
 	va = (vsid << 28) | (ea & 0x0fffffff);
-	vpn = va >> PAGE_SHIFT;
+	vpn = va >> HW_PAGE_SHIFT;
 	slot = iSeries_hpte_find(vpn);
 	if (slot == -1)
 		panic("updateboltedpp: Could not find page to bolt\n");
@@ -225,7 +222,7 @@ static void iSeries_hpte_updateboltedpp(unsigned long newpp, unsigned long ea)
 }
 
 static void iSeries_hpte_invalidate(unsigned long slot, unsigned long va,
-				    int large, int local)
+				    int psize, int local)
 {
 	unsigned long hpte_v;
 	unsigned long avpn = va >> 23;