[Early RFC 0/6] arch/powerpc: Add 64TB support to ppc64

[Aneesh Kumar K.V]

"Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com> writes:

> Hi,
>
> This patchset include preparatory patches for supporting 64TB with ppc64. I haven't
> completed the actual patch that bump the USER_ESID bits. I wanted the share the
> changes early so that I can get feedback on the approach. The changes itself
> contains few FIXME!! which I will be addressing in the later updates.
>

Here is the patch that update USER_ESID_BITS. I get a machine check
exception with this changes. That is why I didn't include this in the patch
series. 

commit 5fff8ff606bc136c510350a40528431196f60001
Author: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
Date:   Wed May 23 16:59:36 2012 +0530

    arch/powerpc: Add 64TB support
    
    Increase max addressable range to 64TB. This is not tested on
    real hardware yet.
    
    Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>

diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h
index 0f8b10d..9f9a2a1 100644
--- a/arch/powerpc/include/asm/mmu-hash64.h
+++ b/arch/powerpc/include/asm/mmu-hash64.h
@@ -375,8 +375,8 @@ extern void slb_set_size(u16 size);
 #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))
 
diff --git a/arch/powerpc/include/asm/pgtable-ppc64-4k.h b/arch/powerpc/include/asm/pgtable-ppc64-4k.h
index 6eefdcf..b3eccf2 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 90533dd..be4e287 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 8e2d037..426ed13 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -100,8 +100,8 @@ 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 0c5fa31..f6fc0ee 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 */