diff mbox series

[v2,11/12] arm64: mm: Tweak PAGE_OFFSET logic

Message ID 20190528161026.13193-12-steve.capper@arm.com (mailing list archive)
State New, archived
Headers show
Series 52-bit kernel + user VAs | expand

Commit Message

Steve Capper May 28, 2019, 4:10 p.m. UTC 
This patch introduces _PAGE_OFFSET(va) to allow for computing the
largest possible direct linear map for use with 48/52-bit selectable
kernel VAs.

Also, this patch removes the PAGE_OFFSET bit masking logic in
virt_to_pgoff as this optimisation can paint us into a corner for
permissible PAGE_OFFSET values in future.

Lastly, this patch modifies the definition of _virt_addr_valid to use
__virt_to_phys rather than a bitmasked PAGE_OFFSET formula.

Signed-off-by: Steve Capper <steve.capper@arm.com>
---
 arch/arm64/include/asm/memory.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index e9af8aa36612..c817ee71e201 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -55,8 +55,9 @@ 
  * VA_START - the first kernel virtual address.
  */
 #define VA_BITS			(CONFIG_ARM64_VA_BITS)
-#define PAGE_OFFSET		(UL(0xffffffffffffffff) - \
-	(UL(1) << VA_BITS) + 1)
+#define _PAGE_OFFSET(va)	(UL(0xffffffffffffffff) - \
+					(UL(1) << (va)) + 1)
+#define PAGE_OFFSET		(_PAGE_OFFSET(VA_BITS))
 #define PAGE_OFFSET_END		(VA_START)
 #define KIMAGE_VADDR		(MODULES_END)
 #define BPF_JIT_REGION_START	(KASAN_SHADOW_END)
@@ -325,7 +326,7 @@  static inline void *phys_to_virt(phys_addr_t x)
 #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
 #define _virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
 #else
-#define __virt_to_pgoff(kaddr)	(((u64)(kaddr) & ~PAGE_OFFSET) / PAGE_SIZE * sizeof(struct page))
+#define __virt_to_pgoff(kaddr)	(((u64)(kaddr) - PAGE_OFFSET) / PAGE_SIZE * sizeof(struct page))
 #define __page_to_voff(kaddr)	(((u64)(kaddr) - VMEMMAP_START) * PAGE_SIZE / sizeof(struct page))
 
 #define page_to_virt(page)	({					\
@@ -338,8 +339,7 @@  static inline void *phys_to_virt(phys_addr_t x)
 
 #define virt_to_page(vaddr)	((struct page *)((__virt_to_pgoff(vaddr)) | VMEMMAP_START))
 
-#define _virt_addr_valid(kaddr)	pfn_valid((((u64)(kaddr) & ~PAGE_OFFSET) \
-					   + PHYS_OFFSET) >> PAGE_SHIFT)
+#define _virt_addr_valid(kaddr)	pfn_valid(__virt_to_phys((u64)(kaddr)) >> PAGE_SHIFT)
 #endif
 #endif