[PATCH 1/8] ppc64: fix vtop page translation for 4K pages

[hbathini@xxxxxxxxxxxxxxxxxx (Hari Bathini)]

PUD index size was changed to 9 from 7 since kernel v3.7, but it was
not updated here. Also, currently L4_MASK is set to 0xfff for kernel
v3.10 and above irrespective of page size but it should be based on
l4 index size which is different for 4k & 64K page sizes. This patch
fixes them.

Signed-off-by: Hari Bathini <hbathini at linux.vnet.ibm.com>
---
 arch/ppc64.c   |   10 +++++++---
 makedumpfile.h |    5 ++++-
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/ppc64.c b/arch/ppc64.c
index 89a7f05..2cc3906 100644
--- a/arch/ppc64.c
+++ b/arch/ppc64.c
@@ -160,10 +160,12 @@ ppc64_vmalloc_init(void)
 			info->l1_index_size = PTE_INDEX_SIZE_L4_64K_3_10;
 			info->l2_index_size = PMD_INDEX_SIZE_L4_64K_3_10;
 			info->l3_index_size = PUD_INDEX_SIZE_L4_64K;
+			info->l4_index_size = PGD_INDEX_SIZE_L4_64K_3_10;
 		} else {
 			info->l1_index_size = PTE_INDEX_SIZE_L4_64K;
 			info->l2_index_size = PMD_INDEX_SIZE_L4_64K;
 			info->l3_index_size = PUD_INDEX_SIZE_L4_64K;
+			info->l4_index_size = PGD_INDEX_SIZE_L4_64K;
 		}
 
 		info->pte_shift = SYMBOL(demote_segment_4k) ?
@@ -175,7 +177,9 @@ ppc64_vmalloc_init(void)
 		 */
 		info->l1_index_size = PTE_INDEX_SIZE_L4_4K;
 		info->l2_index_size = PMD_INDEX_SIZE_L4_4K;
-		info->l3_index_size = PUD_INDEX_SIZE_L4_4K;
+		info->l3_index_size = (info->kernel_version >= KERNEL_VERSION(3, 7, 0) ?
+			PUD_INDEX_SIZE_L4_4K_3_7 : PUD_INDEX_SIZE_L4_4K);
+		info->l4_index_size = PGD_INDEX_SIZE_L4_4K;
 
 		info->pte_shift = PTE_SHIFT_L4_4K;
 		info->l2_masked_bits = PMD_MASKED_BITS_4K;
@@ -188,8 +192,8 @@ ppc64_vmalloc_init(void)
 	info->ptrs_per_l1 = (1 << info->l1_index_size);
 	info->ptrs_per_l2 = (1 << info->l2_index_size);
 	info->ptrs_per_l3 = (1 << info->l3_index_size);
-
-	info->ptrs_per_pgd = info->ptrs_per_l3;
+	info->ptrs_per_l4 = (1 << info->l4_index_size);
+	info->ptrs_per_pgd = info->ptrs_per_l4;
 
 	/*
 	 * Compute shifts
diff --git a/makedumpfile.h b/makedumpfile.h
index 1814139..46c940c 100644
--- a/makedumpfile.h
+++ b/makedumpfile.h
@@ -650,6 +650,7 @@ int get_va_bits_arm64(void);
 #define PMD_INDEX_SIZE_L4_4K  7
 #define PUD_INDEX_SIZE_L4_4K  7
 #define PGD_INDEX_SIZE_L4_4K  9
+#define PUD_INDEX_SIZE_L4_4K_3_7  9
 #define PTE_SHIFT_L4_4K  17
 #define PMD_MASKED_BITS_4K  0
 
@@ -666,7 +667,7 @@ int get_va_bits_arm64(void);
 #define PMD_MASKED_BITS_64K  0x1ff
 
 #define L4_MASK		\
-	(info->kernel_version >= KERNEL_VERSION(3, 10, 0) ? 0xfff : 0x1ff)
+	(info->kernel_version >= KERNEL_VERSION(3, 10, 0) ? (info->ptrs_per_pgd - 1) : 0x1ff)
 #define L4_OFFSET(vaddr)	((vaddr >> (info->l4_shift)) & L4_MASK)
 
 #define PGD_OFFSET_L4(vaddr)	\
@@ -1123,9 +1124,11 @@ struct DumpInfo {
 	 * page table info for ppc64
 	 */
 	int		ptrs_per_pgd;
+	uint		l4_index_size;
 	uint		l3_index_size;
 	uint		l2_index_size;
 	uint		l1_index_size;
+	uint		ptrs_per_l4;
 	uint		ptrs_per_l3;
 	uint		ptrs_per_l2;
 	uint		ptrs_per_l1;