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From: Steve Capper <steve.capper@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: crecklin@redhat.com, ard.biesheuvel@linaro.org,
	marc.zyngier@arm.com, catalin.marinas@arm.com,
	bhsharma@redhat.com, will.deacon@arm.com
Subject: [PATCH v2 11/12] arm64: mm: Tweak PAGE_OFFSET logic
Date: Tue, 28 May 2019 17:10:25 +0100	[thread overview]
Message-ID: <20190528161026.13193-12-steve.capper@arm.com> (raw)
In-Reply-To: <20190528161026.13193-1-steve.capper@arm.com>

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 --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
 
-- 
2.20.1


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  parent reply	other threads:[~2019-05-28 16:13 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-28 16:10 [PATCH v2 00/12] 52-bit kernel + user VAs Steve Capper
2019-05-28 16:10 ` [PATCH v2 01/12] arm/arm64: KVM: Formalise end of direct linear map Steve Capper
2019-05-28 16:27   ` Marc Zyngier
2019-05-28 17:01     ` Steve Capper
2019-05-29  9:26       ` Steve Capper
2019-05-28 16:10 ` [PATCH v2 02/12] arm64: mm: Flip kernel VA space Steve Capper
2019-05-28 16:10 ` [PATCH v2 03/12] arm64: kasan: Switch to using KASAN_SHADOW_OFFSET Steve Capper
2019-05-28 16:10 ` [PATCH v2 04/12] arm64: mm: Replace fixed map BUILD_BUG_ON's with BUG_ON's Steve Capper
2019-05-28 17:07   ` Ard Biesheuvel
2019-05-28 17:11     ` Ard Biesheuvel
2019-05-29  9:28       ` Steve Capper
2019-05-28 16:10 ` [PATCH v2 05/12] arm64: dump: Make kernel page table dumper dynamic again Steve Capper
2019-05-28 16:10 ` [PATCH v2 06/12] arm64: mm: Introduce VA_BITS_MIN Steve Capper
2019-05-28 16:10 ` [PATCH v2 07/12] arm64: mm: Introduce VA_BITS_ACTUAL Steve Capper
2019-05-28 16:10 ` [PATCH v2 08/12] arm64: mm: Logic to make offset_ttbr1 conditional Steve Capper
2019-06-10 14:18   ` Catalin Marinas
2019-06-12 10:58     ` Steve Capper
2019-05-28 16:10 ` [PATCH v2 09/12] arm64: mm: Separate out vmemmap Steve Capper
2019-05-28 16:10 ` [PATCH v2 10/12] arm64: mm: Modify calculation of VMEMMAP_SIZE Steve Capper
2019-05-28 16:10 ` Steve Capper [this message]
2019-05-28 16:10 ` [PATCH v2 12/12] arm64: mm: Introduce 52-bit Kernel VAs Steve Capper
2019-06-05 15:34   ` Catalin Marinas
2019-06-07 10:34     ` Steve Capper
2019-06-07 13:53 ` [PATCH v2 00/12] 52-bit kernel + user VAs Anshuman Khandual
2019-06-07 14:24   ` Steve Capper
2019-06-10 10:40 ` Bhupesh Sharma
2019-06-10 10:54   ` Catalin Marinas
2019-06-10 11:15     ` Bhupesh Sharma

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