[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>
diff --git a/arch/powerpc/platforms/cell/spu_base.c b/arch/powerpc/platforms/cell/spu_base.c
index b5a2117..c83c3e3 100644
--- a/arch/powerpc/platforms/cell/spu_base.c
+++ b/arch/powerpc/platforms/cell/spu_base.c
@@ -168,7 +168,7 @@
 #else
 		psize = mm->context.user_psize;
 #endif
-		vsid = (get_vsid(mm->context.id, ea) << SLB_VSID_SHIFT) |
+		vsid = (get_vsid(mm->context.id, ea, MMU_SEGSIZE_256M) << SLB_VSID_SHIFT) |
 				SLB_VSID_USER;
 		break;
 	case VMALLOC_REGION_ID:
@@ -176,12 +176,12 @@
 			psize = mmu_vmalloc_psize;
 		else
 			psize = mmu_io_psize;
-		vsid = (get_kernel_vsid(ea) << SLB_VSID_SHIFT) |
+		vsid = (get_kernel_vsid(ea, MMU_SEGSIZE_256M) << SLB_VSID_SHIFT) |
 			SLB_VSID_KERNEL;
 		break;
 	case KERNEL_REGION_ID:
 		psize = mmu_linear_psize;
-		vsid = (get_kernel_vsid(ea) << SLB_VSID_SHIFT) |
+		vsid = (get_kernel_vsid(ea, MMU_SEGSIZE_256M) << SLB_VSID_SHIFT) |
 			SLB_VSID_KERNEL;
 		break;
 	default:
diff --git a/arch/powerpc/platforms/cell/spufs/switch.c b/arch/powerpc/platforms/cell/spufs/switch.c
index de7e5ee..3d64c81 100644
--- a/arch/powerpc/platforms/cell/spufs/switch.c
+++ b/arch/powerpc/platforms/cell/spufs/switch.c
@@ -699,7 +699,7 @@
 		llp = mmu_psize_defs[mmu_linear_psize].sllp;
 	else
 		llp = mmu_psize_defs[mmu_virtual_psize].sllp;
-	slb[0] = (get_kernel_vsid(ea) << SLB_VSID_SHIFT) |
+	slb[0] = (get_kernel_vsid(ea, MMU_SEGSIZE_256M) << SLB_VSID_SHIFT) |
 		SLB_VSID_KERNEL | llp;
 	slb[1] = (ea & ESID_MASK) | SLB_ESID_V;
 }
diff --git a/arch/powerpc/platforms/celleb/htab.c b/arch/powerpc/platforms/celleb/htab.c
index 5e75c77..fbf27c7 100644
--- a/arch/powerpc/platforms/celleb/htab.c
+++ b/arch/powerpc/platforms/celleb/htab.c
@@ -90,7 +90,7 @@
 static long beat_lpar_hpte_insert(unsigned long hpte_group,
 				  unsigned long va, unsigned long pa,
 				  unsigned long rflags, unsigned long vflags,
-				  int psize)
+				  int psize, int ssize)
 {
 	unsigned long lpar_rc;
 	unsigned long slot;
@@ -105,7 +105,8 @@
 			"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_v = hpte_encode_v(va, psize, MMU_SEGSIZE_256M) |
+		vflags | HPTE_V_VALID;
 	hpte_r = hpte_encode_r(pa, psize) | rflags;
 
 	if (!(vflags & HPTE_V_BOLTED))
@@ -184,12 +185,12 @@
 static long beat_lpar_hpte_updatepp(unsigned long slot,
 				    unsigned long newpp,
 				    unsigned long va,
-				    int psize, int local)
+				    int psize, int ssize, int local)
 {
 	unsigned long lpar_rc;
 	unsigned long dummy0, dummy1, want_v;
 
-	want_v = hpte_encode_v(va, psize);
+	want_v = hpte_encode_v(va, psize, MMU_SEGSIZE_256M);
 
 	DBG_LOW("    update: "
 		"avpnv=%016lx, slot=%016lx, psize: %d, newpp %016lx ... ",
@@ -225,8 +226,8 @@
 	long slot;
 	unsigned long want_v, hpte_v;
 
-	hash = hpt_hash(va, mmu_psize_defs[psize].shift);
-	want_v = hpte_encode_v(va, psize);
+	hash = hpt_hash(va, mmu_psize_defs[psize].shift, MMU_SEGSIZE_256M);
+	want_v = hpte_encode_v(va, psize, MMU_SEGSIZE_256M);
 
 	for (j = 0; j < 2; j++) {
 		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
@@ -251,11 +252,11 @@
 
 static void beat_lpar_hpte_updateboltedpp(unsigned long newpp,
 					  unsigned long ea,
-					  int psize)
+					  int psize, int ssize)
 {
 	unsigned long lpar_rc, slot, vsid, va, dummy0, dummy1;
 
-	vsid = get_kernel_vsid(ea);
+	vsid = get_kernel_vsid(ea, MMU_SEGSIZE_256M);
 	va = (vsid << 28) | (ea & 0x0fffffff);
 
 	spin_lock(&beat_htab_lock);
@@ -270,7 +271,7 @@
 }
 
 static void beat_lpar_hpte_invalidate(unsigned long slot, unsigned long va,
-					 int psize, int local)
+					 int psize, int ssize, int local)
 {
 	unsigned long want_v;
 	unsigned long lpar_rc;
@@ -279,7 +280,7 @@
 
 	DBG_LOW("    inval : slot=%lx, va=%016lx, psize: %d, local: %d\n",
 		slot, va, psize, local);
-	want_v = hpte_encode_v(va, psize);
+	want_v = hpte_encode_v(va, psize, MMU_SEGSIZE_256M);
 
 	spin_lock_irqsave(&beat_htab_lock, flags);
 	dummy1 = beat_lpar_hpte_getword0(slot);
@@ -310,7 +311,7 @@
 static long beat_lpar_hpte_insert_v3(unsigned long hpte_group,
 				  unsigned long va, unsigned long pa,
 				  unsigned long rflags, unsigned long vflags,
-				  int psize)
+				  int psize, int ssize)
 {
 	unsigned long lpar_rc;
 	unsigned long slot;
@@ -325,7 +326,8 @@
 			"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_v = hpte_encode_v(va, psize, MMU_SEGSIZE_256M) |
+		vflags | HPTE_V_VALID;
 	hpte_r = hpte_encode_r(pa, psize) | rflags;
 
 	if (!(vflags & HPTE_V_BOLTED))
@@ -363,13 +365,13 @@
 static long beat_lpar_hpte_updatepp_v3(unsigned long slot,
 				    unsigned long newpp,
 				    unsigned long va,
-				    int psize, int local)
+				    int psize, int ssize, int local)
 {
 	unsigned long lpar_rc;
 	unsigned long want_v;
 	unsigned long pss;
 
-	want_v = hpte_encode_v(va, psize);
+	want_v = hpte_encode_v(va, psize, MMU_SEGSIZE_256M);
 	pss = (psize == MMU_PAGE_4K) ? -1UL : mmu_psize_defs[psize].penc;
 
 	DBG_LOW("    update: "
@@ -391,7 +393,7 @@
 }
 
 static void beat_lpar_hpte_invalidate_v3(unsigned long slot, unsigned long va,
-					 int psize, int local)
+					 int psize, int ssize, int local)
 {
 	unsigned long want_v;
 	unsigned long lpar_rc;
@@ -399,7 +401,7 @@
 
 	DBG_LOW("    inval : slot=%lx, va=%016lx, psize: %d, local: %d\n",
 		slot, va, psize, local);
-	want_v = hpte_encode_v(va, psize);
+	want_v = hpte_encode_v(va, psize, MMU_SEGSIZE_256M);
 	pss = (psize == MMU_PAGE_4K) ? -1UL : mmu_psize_defs[psize].penc;
 
 	lpar_rc = beat_invalidate_htab_entry3(0, slot, want_v, pss);
diff --git a/arch/powerpc/platforms/iseries/htab.c b/arch/powerpc/platforms/iseries/htab.c
index b4e2c7a..15a7097 100644
--- a/arch/powerpc/platforms/iseries/htab.c
+++ b/arch/powerpc/platforms/iseries/htab.c
@@ -86,7 +86,8 @@
 	}
 
 
- 	lhpte.v = hpte_encode_v(va, MMU_PAGE_4K) | vflags | HPTE_V_VALID;
+	lhpte.v = hpte_encode_v(va, MMU_PAGE_4K, MMU_SEGSIZE_256M) |
+		vflags | HPTE_V_VALID;
 	lhpte.r = hpte_encode_r(phys_to_abs(pa), MMU_PAGE_4K) | rflags;
 
 	/* Now fill in the actual HPTE */
@@ -142,7 +143,7 @@
  *	bits 61..63 : PP2,PP1,PP0
  */
 static long iSeries_hpte_updatepp(unsigned long slot, unsigned long newpp,
-				  unsigned long va, int psize, int local)
+			unsigned long va, int psize, int ssize, int local)
 {
 	struct hash_pte hpte;
 	unsigned long want_v;
@@ -150,7 +151,7 @@
 	iSeries_hlock(slot);
 
 	HvCallHpt_get(&hpte, slot);
-	want_v = hpte_encode_v(va, MMU_PAGE_4K);
+	want_v = hpte_encode_v(va, MMU_PAGE_4K, MMU_SEGSIZE_256M);
 
 	if (HPTE_V_COMPARE(hpte.v, want_v) && (hpte.v & HPTE_V_VALID)) {
 		/*
@@ -205,14 +206,14 @@
  * No need to lock here because we should be the only user.
  */
 static void iSeries_hpte_updateboltedpp(unsigned long newpp, unsigned long ea,
-					int psize)
+					int psize, int ssize)
 {
 	unsigned long vsid,va,vpn;
 	long slot;
 
 	BUG_ON(psize != MMU_PAGE_4K);
 
-	vsid = get_kernel_vsid(ea);
+	vsid = get_kernel_vsid(ea, MMU_SEGSIZE_256M);
 	va = (vsid << 28) | (ea & 0x0fffffff);
 	vpn = va >> HW_PAGE_SHIFT;
 	slot = iSeries_hpte_find(vpn);
@@ -222,7 +223,7 @@
 }
 
 static void iSeries_hpte_invalidate(unsigned long slot, unsigned long va,
-				    int psize, int local)
+				    int psize, int ssize, int local)
 {
 	unsigned long hpte_v;
 	unsigned long avpn = va >> 23;
diff --git a/arch/powerpc/platforms/ps3/htab.c b/arch/powerpc/platforms/ps3/htab.c
index 5d2e176..7382f19 100644
--- a/arch/powerpc/platforms/ps3/htab.c
+++ b/arch/powerpc/platforms/ps3/htab.c
@@ -60,7 +60,8 @@
 }
 
 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 @@
 
 	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_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 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;
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index ea327ca..9a455d4 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -284,7 +284,7 @@
 static long pSeries_lpar_hpte_insert(unsigned long hpte_group,
  			      unsigned long va, unsigned long pa,
  			      unsigned long rflags, unsigned long vflags,
- 			      int psize)
+			      int psize, int ssize)
 {
 	unsigned long lpar_rc;
 	unsigned long flags;
@@ -296,7 +296,7 @@
 			"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_v = hpte_encode_v(va, psize, ssize) | vflags | HPTE_V_VALID;
 	hpte_r = hpte_encode_r(pa, psize) | rflags;
 
 	if (!(vflags & HPTE_V_BOLTED))
@@ -392,6 +392,22 @@
 }
 
 /*
+ * This computes the AVPN and B fields of the first dword of a HPTE,
+ * for use when we want to match an existing PTE.  The bottom 7 bits
+ * of the returned value are zero.
+ */
+static inline unsigned long hpte_encode_avpn(unsigned long va, int psize,
+					     int ssize)
+{
+	unsigned long v;
+
+	v = (va >> 23) & ~(mmu_psize_defs[psize].avpnm);
+	v <<= HPTE_V_AVPN_SHIFT;
+	v |= ((unsigned long) ssize) << HPTE_V_SSIZE_SHIFT;
+	return v;
+}
+
+/*
  * NOTE: for updatepp ops we are fortunate that the linux "newpp" bits and
  * the low 3 bits of flags happen to line up.  So no transform is needed.
  * We can probably optimize here and assume the high bits of newpp are
@@ -400,18 +416,18 @@
 static long pSeries_lpar_hpte_updatepp(unsigned long slot,
 				       unsigned long newpp,
 				       unsigned long va,
-				       int psize, int local)
+				       int psize, int ssize, int local)
 {
 	unsigned long lpar_rc;
 	unsigned long flags = (newpp & 7) | H_AVPN;
 	unsigned long want_v;
 
-	want_v = hpte_encode_v(va, psize);
+	want_v = hpte_encode_avpn(va, psize, ssize);
 
 	DBG_LOW("    update: avpnv=%016lx, hash=%016lx, f=%x, psize: %d ... ",
-		want_v & HPTE_V_AVPN, slot, flags, psize);
+		want_v, slot, flags, psize);
 
-	lpar_rc = plpar_pte_protect(flags, slot, want_v & HPTE_V_AVPN);
+	lpar_rc = plpar_pte_protect(flags, slot, want_v);
 
 	if (lpar_rc == H_NOT_FOUND) {
 		DBG_LOW("not found !\n");
@@ -444,32 +460,25 @@
 	return dword0;
 }
 
-static long pSeries_lpar_hpte_find(unsigned long va, int psize)
+static long pSeries_lpar_hpte_find(unsigned long va, int psize, int ssize)
 {
 	unsigned long hash;
-	unsigned long i, j;
+	unsigned long i;
 	long slot;
 	unsigned long want_v, hpte_v;
 
-	hash = hpt_hash(va, mmu_psize_defs[psize].shift);
-	want_v = hpte_encode_v(va, psize);
+	hash = hpt_hash(va, mmu_psize_defs[psize].shift, ssize);
+	want_v = hpte_encode_avpn(va, psize, ssize);
 
-	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);
+	/* Bolted entries are always in the primary group */
+	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_COMPARE(hpte_v, want_v)
-			    && (hpte_v & HPTE_V_VALID)
-			    && (!!(hpte_v & HPTE_V_SECONDARY) == j)) {
-				/* HPTE matches */
-				if (j)
-					slot = -slot;
-				return slot;
-			}
-			++slot;
-		}
-		hash = ~hash;
+		if (HPTE_V_COMPARE(hpte_v, want_v) && (hpte_v & HPTE_V_VALID))
+			/* HPTE matches */
+			return slot;
+		++slot;
 	}
 
 	return -1;
@@ -477,14 +486,14 @@
 
 static void pSeries_lpar_hpte_updateboltedpp(unsigned long newpp,
 					     unsigned long ea,
-					     int psize)
+					     int psize, int ssize)
 {
 	unsigned long lpar_rc, slot, vsid, va, flags;
 
-	vsid = get_kernel_vsid(ea);
-	va = (vsid << 28) | (ea & 0x0fffffff);
+	vsid = get_kernel_vsid(ea, ssize);
+	va = hpt_va(ea, vsid, ssize);
 
-	slot = pSeries_lpar_hpte_find(va, psize);
+	slot = pSeries_lpar_hpte_find(va, psize, ssize);
 	BUG_ON(slot == -1);
 
 	flags = newpp & 7;
@@ -494,7 +503,7 @@
 }
 
 static void pSeries_lpar_hpte_invalidate(unsigned long slot, unsigned long va,
-					 int psize, int local)
+					 int psize, int ssize, int local)
 {
 	unsigned long want_v;
 	unsigned long lpar_rc;
@@ -503,9 +512,8 @@
 	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);
+	want_v = hpte_encode_avpn(va, psize, ssize);
+	lpar_rc = plpar_pte_remove(H_AVPN, slot, want_v, &dummy1, &dummy2);
 	if (lpar_rc == H_NOT_FOUND)
 		return;
 
@@ -533,18 +541,19 @@
 	unsigned long va;
 	unsigned long hash, index, shift, hidx, slot;
 	real_pte_t pte;
-	int psize;
+	int psize, ssize;
 
 	if (lock_tlbie)
 		spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
 
 	psize = batch->psize;
+	ssize = batch->ssize;
 	pix = 0;
 	for (i = 0; i < number; i++) {
 		va = batch->vaddr[i];
 		pte = batch->pte[i];
 		pte_iterate_hashed_subpages(pte, psize, va, index, shift) {
-			hash = hpt_hash(va, shift);
+			hash = hpt_hash(va, shift, ssize);
 			hidx = __rpte_to_hidx(pte, index);
 			if (hidx & _PTEIDX_SECONDARY)
 				hash = ~hash;
@@ -552,11 +561,11 @@
 			slot += hidx & _PTEIDX_GROUP_IX;
 			if (!firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
 				pSeries_lpar_hpte_invalidate(slot, va, psize,
-							     local);
+							     ssize, local);
 			} else {
 				param[pix] = HBR_REQUEST | HBR_AVPN | slot;
-				param[pix+1] = hpte_encode_v(va, psize) &
-					HPTE_V_AVPN;
+				param[pix+1] = hpte_encode_avpn(va, psize,
+								ssize);
 				pix += 2;
 				if (pix == 8) {
 					rc = plpar_hcall9(H_BULK_REMOVE, param,