From: Anshuman Khandual <anshuman.khandual@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Anshuman Khandual <anshuman.khandual@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Subject: [PATCH] arm64/mm: Drop ARM64_KERNEL_USES_PMD_MAPS
Date: Fri, 23 Sep 2022 18:38:41 +0530 [thread overview]
Message-ID: <20220923130841.1382741-1-anshuman.khandual@arm.com> (raw)
Currently ARM64_KERNEL_USES_PMD_MAPS is an unnecessary abstraction. Kernel
mapping at PMD (aka huge page aka block) level, is only applicable with 4K
base page, which makes it 2MB aligned, a necessary requirement for linear
mapping and physical memory start address. This can be easily achieved by
directly checking against base page size itself. This drops off the macro
ARM64_KERNE_USES_PMD_MAPS which is redundant.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
This applies on v6.0-rc6 after the following patch.
https://lore.kernel.org/all/20220920014951.196191-1-wangkefeng.wang@huawei.com/
arch/arm64/include/asm/kernel-pgtable.h | 33 +++++++++----------------
arch/arm64/mm/mmu.c | 2 +-
2 files changed, 12 insertions(+), 23 deletions(-)
diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h
index 32d14f481f0c..5c2f72bae2ca 100644
--- a/arch/arm64/include/asm/kernel-pgtable.h
+++ b/arch/arm64/include/asm/kernel-pgtable.h
@@ -18,11 +18,6 @@
* with 4K (section size = 2M) but not with 16K (section size = 32M) or
* 64K (section size = 512M).
*/
-#ifdef CONFIG_ARM64_4K_PAGES
-#define ARM64_KERNEL_USES_PMD_MAPS 1
-#else
-#define ARM64_KERNEL_USES_PMD_MAPS 0
-#endif
/*
* The idmap and swapper page tables need some space reserved in the kernel
@@ -34,10 +29,20 @@
* VA range, so pages required to map highest possible PA are reserved in all
* cases.
*/
-#if ARM64_KERNEL_USES_PMD_MAPS
+#ifdef CONFIG_ARM64_4K_PAGES
#define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS - 1)
+#define SWAPPER_BLOCK_SHIFT PMD_SHIFT
+#define SWAPPER_BLOCK_SIZE PMD_SIZE
+#define SWAPPER_TABLE_SHIFT PUD_SHIFT
+#define SWAPPER_RW_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS)
+#define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PMD_SECT_RDONLY)
#else
#define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS)
+#define SWAPPER_BLOCK_SHIFT PAGE_SHIFT
+#define SWAPPER_BLOCK_SIZE PAGE_SIZE
+#define SWAPPER_TABLE_SHIFT PMD_SHIFT
+#define SWAPPER_RW_MMUFLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS)
+#define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PTE_RDONLY)
#endif
@@ -96,15 +101,6 @@
#define INIT_IDMAP_DIR_PAGES EARLY_PAGES(KIMAGE_VADDR, _end + MAX_FDT_SIZE + SWAPPER_BLOCK_SIZE, 1)
/* Initial memory map size */
-#if ARM64_KERNEL_USES_PMD_MAPS
-#define SWAPPER_BLOCK_SHIFT PMD_SHIFT
-#define SWAPPER_BLOCK_SIZE PMD_SIZE
-#define SWAPPER_TABLE_SHIFT PUD_SHIFT
-#else
-#define SWAPPER_BLOCK_SHIFT PAGE_SHIFT
-#define SWAPPER_BLOCK_SIZE PAGE_SIZE
-#define SWAPPER_TABLE_SHIFT PMD_SHIFT
-#endif
/*
* Initial memory map attributes.
@@ -112,13 +108,6 @@
#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
-#if ARM64_KERNEL_USES_PMD_MAPS
-#define SWAPPER_RW_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS)
-#define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PMD_SECT_RDONLY)
-#else
-#define SWAPPER_RW_MMUFLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS)
-#define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PTE_RDONLY)
-#endif
/*
* To make optimal use of block mappings when laying out the linear
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 69deed27dec8..df1eac788c33 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1192,7 +1192,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END));
- if (!ARM64_KERNEL_USES_PMD_MAPS)
+ if (!IS_ENABLED(CONFIG_ARM64_4K_PAGES))
return vmemmap_populate_basepages(start, end, node, altmap);
do {
--
2.20.1
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next reply other threads:[~2022-09-23 13:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-23 13:08 Anshuman Khandual [this message]
2022-09-23 13:38 ` [PATCH] arm64/mm: Drop ARM64_KERNEL_USES_PMD_MAPS Joey Gouly
2022-09-26 3:18 ` Anshuman Khandual
2022-11-07 15:22 ` Will Deacon
2022-11-08 2:32 ` Anshuman Khandual
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