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authorArd Biesheuvel <ardb@kernel.org>2020-10-08 17:36:02 +0200
committerCatalin Marinas <catalin.marinas@arm.com>2020-11-09 17:15:37 +0000
commit9ad7c6d5e75b160c9ce5775db610d964af45b83f (patch)
tree37243b66291273cdebb475829945fda5b039a415
parentarm64: mm: make vmemmap region a projection of the linear region (diff)
downloadlinux-dev-9ad7c6d5e75b160c9ce5775db610d964af45b83f.tar.xz
linux-dev-9ad7c6d5e75b160c9ce5775db610d964af45b83f.zip
arm64: mm: tidy up top of kernel VA space
Tidy up the way the top of the kernel VA space is organized, by mirroring the 256 MB region we have below the vmalloc space, and populating it top down with the PCI I/O space, some guard regions, and the fixmap region. The latter region is itself populated top down, and today only covers about 4 MB, and so 224 MB is ample, and no guard region is therefore required. The resulting layout is identical between 48-bit/4k and 52-bit/64k configurations. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Steve Capper <steve.capper@arm.com> Link: https://lore.kernel.org/r/20201008153602.9467-5-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--Documentation/arm64/memory.rst22
-rw-r--r--arch/arm64/include/asm/memory.h4
-rw-r--r--arch/arm64/include/asm/pgtable.h2
3 files changed, 13 insertions, 15 deletions
diff --git a/Documentation/arm64/memory.rst b/Documentation/arm64/memory.rst
index 476edb6015b2..3d62604fa7bd 100644
--- a/Documentation/arm64/memory.rst
+++ b/Documentation/arm64/memory.rst
@@ -35,12 +35,11 @@ AArch64 Linux memory layout with 4KB pages + 4 levels (48-bit)::
[ ffff600000000000 ffff7fffffffffff ] 32TB [ kasan shadow region ]
ffff800000000000 ffff800007ffffff 128MB bpf jit region
ffff800008000000 ffff80000fffffff 128MB modules
- ffff800010000000 fffffbffbffeffff 123TB vmalloc
- fffffbffbfff0000 fffffbfffe7f8fff ~998MB [guard region]
- fffffbfffe7f9000 fffffbfffebfffff 4124KB fixed mappings
- fffffbfffec00000 fffffbfffedfffff 2MB [guard region]
- fffffbfffee00000 fffffbffffdfffff 16MB PCI I/O space
- fffffbffffe00000 fffffbffffffffff 2MB [guard region]
+ ffff800010000000 fffffbffefffffff 124TB vmalloc
+ fffffbfff0000000 fffffbfffdffffff 224MB fixed mappings (top down)
+ fffffbfffe000000 fffffbfffe7fffff 8MB [guard region]
+ fffffbfffe800000 fffffbffff7fffff 16MB PCI I/O space
+ fffffbffff800000 fffffbffffffffff 8MB [guard region]
fffffc0000000000 fffffdffffffffff 2TB vmemmap
fffffe0000000000 ffffffffffffffff 2TB [guard region]
@@ -54,12 +53,11 @@ AArch64 Linux memory layout with 64KB pages + 3 levels (52-bit with HW support):
[ fffd800000000000 ffff7fffffffffff ] 512TB [ kasan shadow region ]
ffff800000000000 ffff800007ffffff 128MB bpf jit region
ffff800008000000 ffff80000fffffff 128MB modules
- ffff800010000000 fffff81ffffeffff 120TB vmalloc
- fffff81fffff0000 fffffbfffe38ffff ~3TB [guard region]
- fffffbfffe390000 fffffbfffebfffff 4544KB fixed mappings
- fffffbfffec00000 fffffbfffedfffff 2MB [guard region]
- fffffbfffee00000 fffffbffffdfffff 16MB PCI I/O space
- fffffbffffe00000 fffffbffffffffff 2MB [guard region]
+ ffff800010000000 fffffbffefffffff 124TB vmalloc
+ fffffbfff0000000 fffffbfffdffffff 224MB fixed mappings (top down)
+ fffffbfffe000000 fffffbfffe7fffff 8MB [guard region]
+ fffffbfffe800000 fffffbffff7fffff 16MB PCI I/O space
+ fffffbffff800000 fffffbffffffffff 8MB [guard region]
fffffc0000000000 ffffffdfffffffff ~4TB vmemmap
ffffffe000000000 ffffffffffffffff 128GB [guard region]
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index ecd6342e27ca..03e9b112bd94 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -52,9 +52,9 @@
#define MODULES_VSIZE (SZ_128M)
#define VMEMMAP_START (-(UL(1) << (VA_BITS - VMEMMAP_SHIFT)))
#define VMEMMAP_END (VMEMMAP_START + VMEMMAP_SIZE)
-#define PCI_IO_END (VMEMMAP_START - SZ_2M)
+#define PCI_IO_END (VMEMMAP_START - SZ_8M)
#define PCI_IO_START (PCI_IO_END - PCI_IO_SIZE)
-#define FIXADDR_TOP (PCI_IO_START - SZ_2M)
+#define FIXADDR_TOP (VMEMMAP_START - SZ_32M)
#if VA_BITS > 48
#define VA_BITS_MIN (48)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 4ff12a7adcfd..ec307b8bcb15 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -22,7 +22,7 @@
* and fixed mappings
*/
#define VMALLOC_START (MODULES_END)
-#define VMALLOC_END (- PUD_SIZE - VMEMMAP_SIZE - SZ_64K)
+#define VMALLOC_END (VMEMMAP_START - SZ_256M)
#define vmemmap ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT))