[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, 73 insertions, 42 deletions

diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index e384a5a9179607..ab0c6dd6ec9453 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -19,7 +19,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
-#define DEBUG
+#undef DEBUG_LOW
 
 #include <linux/config.h>
 #include <linux/kernel.h>
@@ -41,10 +41,10 @@
 
 #include "plpar_wrappers.h"
 
-#ifdef DEBUG
-#define DBG(fmt...) udbg_printf(fmt)
+#ifdef DEBUG_LOW
+#define DBG_LOW(fmt...) do { udbg_printf(fmt); } while(0)
 #else
-#define DBG(fmt...)
+#define DBG_LOW(fmt...) do { } while(0)
 #endif
 
 /* in pSeries_hvCall.S */
@@ -276,8 +276,9 @@ void vpa_init(int cpu)
 }
 
 long pSeries_lpar_hpte_insert(unsigned long hpte_group,
-			      unsigned long va, unsigned long prpn,
-			      unsigned long vflags, unsigned long rflags)
+ 			      unsigned long va, unsigned long pa,
+ 			      unsigned long rflags, unsigned long vflags,
+ 			      int psize)
 {
 	unsigned long lpar_rc;
 	unsigned long flags;
@@ -285,11 +286,28 @@ long pSeries_lpar_hpte_insert(unsigned long hpte_group,
 	unsigned long hpte_v, hpte_r;
 	unsigned long dummy0, dummy1;
 
-	hpte_v = ((va >> 23) << HPTE_V_AVPN_SHIFT) | vflags | HPTE_V_VALID;
-	if (vflags & HPTE_V_LARGE)
-		hpte_v &= ~(1UL << HPTE_V_AVPN_SHIFT);
-
-	hpte_r = (prpn << HPTE_R_RPN_SHIFT) | rflags;
+	if (!(vflags & HPTE_V_BOLTED))
+		DBG_LOW("hpte_insert(group=%lx, va=%016lx, pa=%016lx, "
+			"rflags=%lx, vflags=%lx, psize=%d)\n",
+		hpte_group, va, pa, rflags, vflags, psize);
+
+ 	hpte_v = hpte_encode_v(va, psize) | vflags | HPTE_V_VALID;
+	hpte_r = hpte_encode_r(pa, psize) | rflags;
+
+	if (!(vflags & HPTE_V_BOLTED))
+		DBG_LOW(" hpte_v=%016lx, hpte_r=%016lx\n", hpte_v, hpte_r);
+
+#if 1
+	{
+		int i;
+		for (i=0;i<8;i++) {
+			unsigned long w0, w1;
+			plpar_pte_read(0, hpte_group, &w0, &w1);
+			BUG_ON (HPTE_V_COMPARE(hpte_v, w0)
+				&& (w0 & HPTE_V_VALID));
+		}
+	}
+#endif
 
 	/* Now fill in the actual HPTE */
 	/* Set CEC cookie to 0         */
@@ -299,23 +317,30 @@ long pSeries_lpar_hpte_insert(unsigned long hpte_group,
 	/* Exact = 0                   */
 	flags = 0;
 
-	/* XXX why is this here? - Anton */
+	/* Make pHyp happy */
 	if (rflags & (_PAGE_GUARDED|_PAGE_NO_CACHE))
 		hpte_r &= ~_PAGE_COHERENT;
 
 	lpar_rc = plpar_hcall(H_ENTER, flags, hpte_group, hpte_v,
 			      hpte_r, &slot, &dummy0, &dummy1);
-
-	if (unlikely(lpar_rc == H_PTEG_Full))
+	if (unlikely(lpar_rc == H_PTEG_Full)) {
+		if (!(vflags & HPTE_V_BOLTED))
+			DBG_LOW(" full\n");
 		return -1;
+	}
 
 	/*
 	 * Since we try and ioremap PHBs we don't own, the pte insert
 	 * will fail. However we must catch the failure in hash_page
 	 * or we will loop forever, so return -2 in this case.
 	 */
-	if (unlikely(lpar_rc != H_Success))
+	if (unlikely(lpar_rc != H_Success)) {
+		if (!(vflags & HPTE_V_BOLTED))
+			DBG_LOW(" lpar err %d\n", lpar_rc);
 		return -2;
+	}
+	if (!(vflags & HPTE_V_BOLTED))
+		DBG_LOW(" -> slot: %d\n", slot & 7);
 
 	/* Because of iSeries, we have to pass down the secondary
 	 * bucket bit here as well
@@ -340,10 +365,8 @@ static long pSeries_lpar_hpte_remove(unsigned long hpte_group)
 		/* don't remove a bolted entry */
 		lpar_rc = plpar_pte_remove(H_ANDCOND, hpte_group + slot_offset,
 					   (0x1UL << 4), &dummy1, &dummy2);
-
 		if (lpar_rc == H_Success)
 			return i;
-
 		BUG_ON(lpar_rc != H_Not_Found);
 
 		slot_offset++;
@@ -371,20 +394,28 @@ static void pSeries_lpar_hptab_clear(void)
  * We can probably optimize here and assume the high bits of newpp are
  * already zero.  For now I am paranoid.
  */
-static long pSeries_lpar_hpte_updatepp(unsigned long slot, unsigned long newpp,
-				       unsigned long va, int large, int local)
+static long pSeries_lpar_hpte_updatepp(unsigned long slot,
+				       unsigned long newpp,
+				       unsigned long va,
+				       int psize, int local)
 {
 	unsigned long lpar_rc;
 	unsigned long flags = (newpp & 7) | H_AVPN;
-	unsigned long avpn = va >> 23;
+	unsigned long want_v;
 
-	if (large)
-		avpn &= ~0x1UL;
+	want_v = hpte_encode_v(va, psize);
 
-	lpar_rc = plpar_pte_protect(flags, slot, (avpn << 7));
+	DBG_LOW("    update: avpnv=%016lx, hash=%016lx, f=%x, psize: %d ... ",
+		want_v & HPTE_V_AVPN, slot, flags, psize);
 
-	if (lpar_rc == H_Not_Found)
+	lpar_rc = plpar_pte_protect(flags, slot, want_v & HPTE_V_AVPN);
+
+	if (lpar_rc == H_Not_Found) {
+		DBG_LOW("not found !\n");
 		return -1;
+	}
+
+	DBG_LOW("ok\n");
 
 	BUG_ON(lpar_rc != H_Success);
 
@@ -410,21 +441,22 @@ static unsigned long pSeries_lpar_hpte_getword0(unsigned long slot)
 	return dword0;
 }
 
-static long pSeries_lpar_hpte_find(unsigned long vpn)
+static long pSeries_lpar_hpte_find(unsigned long va, int psize)
 {
 	unsigned long hash;
 	unsigned long i, j;
 	long slot;
-	unsigned long hpte_v;
+	unsigned long want_v, hpte_v;
 
-	hash = hpt_hash(vpn, 0);
+	hash = hpt_hash(va, mmu_psize_defs[psize].shift);
+	want_v = hpte_encode_v(va, psize);
 
 	for (j = 0; j < 2; j++) {
 		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 		for (i = 0; i < HPTES_PER_GROUP; i++) {
 			hpte_v = pSeries_lpar_hpte_getword0(slot);
 
-			if ((HPTE_V_AVPN_VAL(hpte_v) == (vpn >> 11))
+			if (HPTE_V_COMPARE(hpte_v, want_v)
 			    && (hpte_v & HPTE_V_VALID)
 			    && (!!(hpte_v & HPTE_V_SECONDARY) == j)) {
 				/* HPTE matches */
@@ -441,17 +473,15 @@ static long pSeries_lpar_hpte_find(unsigned long vpn)
 } 
 
 static void pSeries_lpar_hpte_updateboltedpp(unsigned long newpp,
-					     unsigned long ea)
+					     unsigned long ea,
+					     int psize)
 {
-	unsigned long lpar_rc;
-	unsigned long vsid, va, vpn, flags;
-	long slot;
+	unsigned long lpar_rc, slot, vsid, va, flags;
 
 	vsid = get_kernel_vsid(ea);
 	va = (vsid << 28) | (ea & 0x0fffffff);
-	vpn = va >> PAGE_SHIFT;
 
-	slot = pSeries_lpar_hpte_find(vpn);
+	slot = pSeries_lpar_hpte_find(va, psize);
 	BUG_ON(slot == -1);
 
 	flags = newpp & 7;
@@ -461,18 +491,18 @@ static void pSeries_lpar_hpte_updateboltedpp(unsigned long newpp,
 }
 
 static void pSeries_lpar_hpte_invalidate(unsigned long slot, unsigned long va,
-					 int large, int local)
+					 int psize, int local)
 {
-	unsigned long avpn = va >> 23;
+	unsigned long want_v;
 	unsigned long lpar_rc;
 	unsigned long dummy1, dummy2;
 
-	if (large)
-		avpn &= ~0x1UL;
-
-	lpar_rc = plpar_pte_remove(H_AVPN, slot, (avpn << 7), &dummy1,
-				   &dummy2);
+	DBG_LOW("    inval : slot=%lx, va=%016lx, psize: %d, local: %d",
+		slot, va, psize, local);
 
+	want_v = hpte_encode_v(va, psize);
+	lpar_rc = plpar_pte_remove(H_AVPN, slot, want_v & HPTE_V_AVPN,
+				   &dummy1, &dummy2);
 	if (lpar_rc == H_Not_Found)
 		return;
 
@@ -494,7 +524,8 @@ void pSeries_lpar_flush_hash_range(unsigned long number, int local)
 		spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
 
 	for (i = 0; i < number; i++)
-		flush_hash_page(batch->vaddr[i], batch->pte[i], local);
+		flush_hash_page(batch->vaddr[i], batch->pte[i],
+				batch->psize, local);
 
 	if (lock_tlbie)
 		spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);