powerpc/mm: Add 64TB support

Increase max addressable range to 64TB. This is not tested on
real hardware yet.

Reviewed-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

5 files changed, 39 insertions, 15 deletions

diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h
index 7cbd541f915f..23730ee65aa0 100644
--- a/arch/powerpc/include/asm/mmu-hash64.h
+++ b/arch/powerpc/include/asm/mmu-hash64.h
@@ -370,17 +370,21 @@ extern void slb_set_size(u16 size);
  * (head.S) and ASM_VSID_SCRAMBLE (below) are changed accordingly.
  */
 
-#define VSID_MULTIPLIER_256M    ASM_CONST(200730139)    /* 28-bit prime */
-#define VSID_BITS_256M          36
+/*
+ * This should be computed such that protovosid * vsid_mulitplier
+ * doesn't overflow 64 bits. It should also be co-prime to vsid_modulus
+ */
+#define VSID_MULTIPLIER_256M    ASM_CONST(12538073)     /* 24-bit prime */
+#define VSID_BITS_256M          38
 #define VSID_MODULUS_256M       ((1UL<<VSID_BITS_256M)-1)
 
 #define VSID_MULTIPLIER_1T      ASM_CONST(12538073)     /* 24-bit prime */
-#define VSID_BITS_1T            24
+#define VSID_BITS_1T            26
 #define VSID_MODULUS_1T         ((1UL<<VSID_BITS_1T)-1)
 
 #define CONTEXT_BITS            19
-#define USER_ESID_BITS          16
-#define USER_ESID_BITS_1T       4
+#define USER_ESID_BITS          18
+#define USER_ESID_BITS_1T       6
 
 #define USER_VSID_RANGE (1UL << (USER_ESID_BITS + SID_SHIFT))
 
@@ -500,12 +504,32 @@ typedef struct {
         })
 #endif /* 1 */
 
-/* This is only valid for addresses >= PAGE_OFFSET */
+/*
+ * This is only valid for addresses >= PAGE_OFFSET
+ * The proto-VSID space is divided into two class
+ * User:   0 to 2^(CONTEXT_BITS + USER_ESID_BITS) -1
+ * kernel: 2^(CONTEXT_BITS + USER_ESID_BITS) to 2^(VSID_BITS) - 1
+ *
+ * With KERNEL_START at 0xc000000000000000, the proto vsid for
+ * the kernel ends up with 0xc00000000 (36 bits). With 64TB
+ * support we need to have kernel proto-VSID in the
+ * [2^37 to 2^38 - 1] range due to the increased USER_ESID_BITS.
+ */
 static inline unsigned long get_kernel_vsid(unsigned long ea, int ssize)
 {
-        if (ssize == MMU_SEGSIZE_256M)
-                return vsid_scramble(ea >> SID_SHIFT, 256M);
-        return vsid_scramble(ea >> SID_SHIFT_1T, 1T);
+        unsigned long proto_vsid;
+        /*
+         * We need to make sure proto_vsid for the kernel is
+         * >= 2^(CONTEXT_BITS + USER_ESID_BITS[_1T])
+         */
+        if (ssize == MMU_SEGSIZE_256M) {
+                proto_vsid = ea >> SID_SHIFT;
+                proto_vsid |= (1UL << (CONTEXT_BITS + USER_ESID_BITS));
+                return vsid_scramble(proto_vsid, 256M);
+        }
+        proto_vsid = ea >> SID_SHIFT_1T;
+        proto_vsid |= (1UL << (CONTEXT_BITS + USER_ESID_BITS_1T));
+        return vsid_scramble(proto_vsid, 1T);
 }
 
 /* Returns the segment size indicator for a user address */
diff --git a/arch/powerpc/include/asm/pgtable-ppc64-4k.h b/arch/powerpc/include/asm/pgtable-ppc64-4k.h
index d6489a2c64c8..12798c9d4b4b 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64-4k.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64-4k.h
@@ -7,7 +7,7 @@
  */
 #define PTE_INDEX_SIZE  9
 #define PMD_INDEX_SIZE  7
-#define PUD_INDEX_SIZE  7
+#define PUD_INDEX_SIZE  9
 #define PGD_INDEX_SIZE  9
 
 #ifndef __ASSEMBLY__
diff --git a/arch/powerpc/include/asm/pgtable-ppc64-64k.h b/arch/powerpc/include/asm/pgtable-ppc64-64k.h
index 90533ddcd703..be4e2878fbc0 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64-64k.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64-64k.h
@@ -7,7 +7,7 @@
 #define PTE_INDEX_SIZE  12
 #define PMD_INDEX_SIZE  12
 #define PUD_INDEX_SIZE  0
-#define PGD_INDEX_SIZE  4
+#define PGD_INDEX_SIZE  6
 
 #ifndef __ASSEMBLY__
 #define PTE_TABLE_SIZE  (sizeof(real_pte_t) << PTE_INDEX_SIZE)
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 83efc6e81543..9dc5cd1fde1a 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -97,8 +97,8 @@ extern struct task_struct *last_task_used_spe;
 #endif
 
 #ifdef CONFIG_PPC64
-/* 64-bit user address space is 44-bits (16TB user VM) */
-#define TASK_SIZE_USER64 (0x0000100000000000UL)
+/* 64-bit user address space is 46-bits (64TB user VM) */
+#define TASK_SIZE_USER64 (0x0000400000000000UL)
 
 /* 
  * 32-bit user address space is 4GB - 1 page 
diff --git a/arch/powerpc/include/asm/sparsemem.h b/arch/powerpc/include/asm/sparsemem.h
index 0c5fa3145615..f6fc0ee813d7 100644
--- a/arch/powerpc/include/asm/sparsemem.h
+++ b/arch/powerpc/include/asm/sparsemem.h
@@ -10,8 +10,8 @@
  */
 #define SECTION_SIZE_BITS       24
 
-#define MAX_PHYSADDR_BITS       44
-#define MAX_PHYSMEM_BITS        44
+#define MAX_PHYSADDR_BITS       46
+#define MAX_PHYSMEM_BITS        46
 
 #endif /* CONFIG_SPARSEMEM */