Subject: [PATCH 3/3] powerpc/book3s64/hash/4K: Update the kernel mapping with 4K page size config.

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Tue, 17 Sep 2019 20:27:02 +0530

This patch updates the kernel mapping such that we now start supporting upto
61TB of memory with 4K. The kernel mapping now looks like below:

vmalloc start     = 0xc0003d0000000000
IO start          = 0xc0003e0000000000
vmemmap start     = 0xc0003f0000000000

Signed-off-by: Aneesh Kumar K.V <[email-masked]>
---
 arch/powerpc/include/asm/book3s/64/hash-4k.h | 13 ++++++-------
 arch/powerpc/include/asm/book3s/64/mmu.h     |  8 ++------
 2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h b/arch/powerpc/include/asm/book3s/64/hash-4k.h
index 8fd8599c9395..d56a2a2ae14a 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-4k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h
@@ -13,20 +13,19 @@
  */
 #define MAX_EA_BITS_PER_CONTEXT		46
 
-#define REGION_SHIFT		(MAX_EA_BITS_PER_CONTEXT - 2)
 
 /*
- * Our page table limit us to 64TB. Hence for the kernel mapping,
- * each MAP area is limited to 16 TB.
- * The four map areas are:  linear mapping, vmap, IO and vmemmap
+ * Our page table limit us to 64TB. For 64TB physical memory, we only need 64GB
+ * of vmemmap space. To better support sparse memory layout, we use 61TB
+ * linear map range, 1TB of vmalloc, 1TB of I/O and 1TB of vmememmap.
  */
+#define REGION_SHIFT		(40)
 #define H_KERN_MAP_SIZE		(ASM_CONST(1) << REGION_SHIFT)
 
 /*
- * Define the address range of the kernel non-linear virtual area
- * 16TB
+ * Define the address range of the kernel non-linear virtual area (61TB)
  */
-#define H_KERN_VIRT_START	ASM_CONST(0xc000100000000000)
+#define H_KERN_VIRT_START	ASM_CONST(0xc0003d0000000000)
 
 #ifndef __ASSEMBLY__
 #define H_PTE_TABLE_SIZE	(sizeof(pte_t) << H_PTE_INDEX_SIZE)
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
index 86cce8189240..bb3deb76c951 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -35,16 +35,12 @@ extern struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
  * memory requirements with large number of sections.
  * 51 bits is the max physical real address on POWER9
  */
-
-#if defined(CONFIG_PPC_64K_PAGES)
-#if defined(CONFIG_SPARSEMEM_VMEMMAP) && defined(CONFIG_SPARSEMEM_EXTREME)
+#if defined(CONFIG_SPARSEMEM_VMEMMAP) && defined(CONFIG_SPARSEMEM_EXTREME) &&  \
+	defined(CONFIG_PPC_64K_PAGES)
 #define MAX_PHYSMEM_BITS 51
 #else
 #define MAX_PHYSMEM_BITS 46
 #endif
-#else /* CONFIG_PPC_64K_PAGES */
-#define MAX_PHYSMEM_BITS 44
-#endif
 
 /* 64-bit classic hash table MMU */
 #include <asm/book3s/64/mmu-hash.h>
-- 
2.21.0