From: "Suzuki K. Poulose" <suzuki.poulose@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com,
will.deacon@arm.com, mark.rutland@arm.com,
steve.capper@linaro.org, marc.zyngier@arm.com,
ard.biesheuvel@linaro.org, christoffer.dall@linaro.org,
"Suzuki K. Poulose" <suzuki.poulose@arm.com>
Subject: [PATCHv3 03/11] arm64: Introduce helpers for page table levels
Date: Wed, 14 Oct 2015 12:20:26 +0100 [thread overview]
Message-ID: <1444821634-1689-4-git-send-email-suzuki.poulose@arm.com> (raw)
In-Reply-To: <1444821634-1689-1-git-send-email-suzuki.poulose@arm.com>
Introduce helpers for finding the number of page table
levels required for a given VA width, shift for a particular
page table level.
Convert the existing users to the new helpers. More users
to follow.
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
---
Changes since V2:
- Add comments around the macros
- Change ARM64_HW_PGTABLE_LEVEL_SHIFT to accept pagetable level as
described by ARM ARM
---
arch/arm64/include/asm/pgtable-hwdef.h | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
index 95c1ec0..c6194ab 100644
--- a/arch/arm64/include/asm/pgtable-hwdef.h
+++ b/arch/arm64/include/asm/pgtable-hwdef.h
@@ -16,13 +16,31 @@
#ifndef __ASM_PGTABLE_HWDEF_H
#define __ASM_PGTABLE_HWDEF_H
+/*
+ * Number of page-table levels required to address 'va_bits' wide
+ * address, without section mapping. We resolve the top (va_bits - PAGE_SHIFT)
+ * bits with (PAGE_SHIFT - 3) bits at each page table level. Hence:
+ *
+ * levels = DIV_ROUND_UP((va_bits - PAGE_SHIFT), (PAGE_SHIFT - 3))
+ *
+ * We cannot include linux/kernel.h which defines DIV_ROUND_UP here
+ * due to build issues. So we use the following magic formula.
+ */
+#define ARM64_HW_PGTABLE_LEVELS(va_bits) (((va_bits) - 4) / (PAGE_SHIFT - 3))
+
+/*
+ * Size mapped by an entry at level n
+ * We map PAGE_SHIFT - 3 at all levels, except the PAGE_SHIFT bits at the last level
+ */
+#define ARM64_HW_PGTABLE_LEVEL_SHIFT(n) ((PAGE_SHIFT - 3) * (4 - (n)) + 3)
+
#define PTRS_PER_PTE (1 << (PAGE_SHIFT - 3))
/*
* PMD_SHIFT determines the size a level 2 page table entry can map.
*/
#if CONFIG_PGTABLE_LEVELS > 2
-#define PMD_SHIFT ((PAGE_SHIFT - 3) * 2 + 3)
+#define PMD_SHIFT ARM64_HW_PGTABLE_LEVEL_SHIFT(2)
#define PMD_SIZE (_AC(1, UL) << PMD_SHIFT)
#define PMD_MASK (~(PMD_SIZE-1))
#define PTRS_PER_PMD PTRS_PER_PTE
@@ -32,7 +50,7 @@
* PUD_SHIFT determines the size a level 1 page table entry can map.
*/
#if CONFIG_PGTABLE_LEVELS > 3
-#define PUD_SHIFT ((PAGE_SHIFT - 3) * 3 + 3)
+#define PUD_SHIFT ARM64_HW_PGTABLE_LEVEL_SHIFT(1)
#define PUD_SIZE (_AC(1, UL) << PUD_SHIFT)
#define PUD_MASK (~(PUD_SIZE-1))
#define PTRS_PER_PUD PTRS_PER_PTE
@@ -42,7 +60,8 @@
* PGDIR_SHIFT determines the size a top-level page table entry can map
* (depending on the configuration, this level can be 0, 1 or 2).
*/
-#define PGDIR_SHIFT ((PAGE_SHIFT - 3) * CONFIG_PGTABLE_LEVELS + 3)
+#define PGDIR_SHIFT \
+ ARM64_HW_PGTABLE_LEVEL_SHIFT(4 - CONFIG_PGTABLE_LEVELS)
#define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
#define PTRS_PER_PGD (1 << (VA_BITS - PGDIR_SHIFT))
--
1.7.9.5
next prev parent reply other threads:[~2015-10-14 11:23 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-14 11:20 [PATCHv3 00/11] arm64: 16K translation granule support Suzuki K. Poulose
2015-10-14 11:20 ` [PATCHv3 01/11] arm64: Move swapper pagetable definitions Suzuki K. Poulose
2015-10-14 11:42 ` Mark Rutland
2015-10-14 12:41 ` Suzuki K. Poulose
2015-10-14 11:20 ` [PATCHv3 02/11] arm64: Handle section maps for swapper/idmap Suzuki K. Poulose
2015-10-14 12:06 ` Mark Rutland
2015-10-14 13:21 ` Suzuki K. Poulose
2015-10-14 14:51 ` Mark Rutland
2015-10-14 15:08 ` Suzuki K. Poulose
2015-10-14 15:14 ` Mark Rutland
2015-10-14 11:20 ` Suzuki K. Poulose [this message]
2015-10-14 17:07 ` [PATCHv3 03/11] arm64: Introduce helpers for page table levels Mark Rutland
2015-10-15 9:35 ` Suzuki K. Poulose
2015-10-15 10:37 ` Mark Rutland
2015-10-15 11:40 ` Christoffer Dall
2015-10-15 11:37 ` Christoffer Dall
2015-10-15 12:44 ` Mark Rutland
2015-10-15 13:14 ` Suzuki K. Poulose
2015-10-15 13:30 ` Christoffer Dall
2015-10-15 13:48 ` Suzuki K. Poulose
2015-10-15 14:15 ` Christoffer Dall
2015-10-14 11:20 ` [PATCHv3 04/11] arm64: Calculate size for idmap_pg_dir at compile time Suzuki K. Poulose
2015-10-14 17:12 ` Mark Rutland
2015-10-14 11:20 ` [PATCHv3 05/11] arm64: Handle 4 level page table for swapper Suzuki K. Poulose
2015-10-14 17:15 ` Mark Rutland
2015-10-14 11:20 ` [PATCHv3 06/11] arm64: Clean config usages for page size Suzuki K. Poulose
2015-10-14 11:20 ` [PATCHv3 07/11] arm64: Kconfig: Fix help text about AArch32 support with 64K pages Suzuki K. Poulose
2015-10-14 17:16 ` Mark Rutland
2015-10-14 11:20 ` [PATCHv3 08/11] arm64: Check for selected granule support Suzuki K. Poulose
2015-10-14 17:24 ` Mark Rutland
2015-10-14 17:32 ` Mark Rutland
2015-10-15 9:45 ` Suzuki K. Poulose
2015-10-15 10:39 ` Mark Rutland
2015-10-14 21:13 ` Jeremy Linton
2015-10-15 9:48 ` Suzuki K. Poulose
2015-10-15 10:45 ` Mark Rutland
2015-10-15 11:25 ` Suzuki K. Poulose
2015-10-15 12:37 ` Mark Rutland
2015-10-15 12:58 ` Suzuki K. Poulose
2015-10-16 8:03 ` Ard Biesheuvel
2015-10-15 14:47 ` Jeremy Linton
2015-10-15 15:02 ` Suzuki K. Poulose
2015-10-15 15:11 ` Mark Rutland
2015-10-16 8:11 ` Ard Biesheuvel
2015-10-14 11:20 ` [PATCHv3 09/11] arm64: Add page size to the kernel image header Suzuki K. Poulose
2015-10-14 17:27 ` Mark Rutland
2015-10-15 9:19 ` Suzuki K. Poulose
2015-10-14 11:20 ` [PATCHv3 10/11] arm64: Add 16K page size support Suzuki K. Poulose
2015-10-14 15:40 ` Jeremy Linton
2015-10-14 15:53 ` Suzuki K. Poulose
2015-10-15 14:06 ` Mark Rutland
2015-10-15 14:48 ` Suzuki K. Poulose
2015-10-15 15:36 ` Steve Capper
2015-10-15 15:48 ` Suzuki K. Poulose
2015-10-14 11:20 ` [PATCHv3 11/11] arm64: 36 bit VA Suzuki K. Poulose
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