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-rw-r--r--Documentation/arm64/memory.txt98
-rw-r--r--arch/arm64/include/asm/pgtable.h13
-rw-r--r--arch/arm64/mm/init.c22
3 files changed, 38 insertions, 95 deletions
diff --git a/Documentation/arm64/memory.txt b/Documentation/arm64/memory.txt
index 4c720d698e8e..8845d0847a66 100644
--- a/Documentation/arm64/memory.txt
+++ b/Documentation/arm64/memory.txt
@@ -2,19 +2,18 @@
==============================
Author: Catalin Marinas <catalin.marinas@arm.com>
-Date : 20 February 2012
This document describes the virtual memory layout used by the AArch64
Linux kernel. The architecture allows up to 4 levels of translation
tables with a 4KB page size and up to 3 levels with a 64KB page size.
-AArch64 Linux uses either 3 levels or 4 levels of translation tables with
-the 4KB page configuration, allowing 39-bit (512GB) or 48-bit (256TB)
-virtual addresses, respectively, for both user and kernel. With 64KB
-pages, only 2 levels of translation tables, allowing 42-bit (4TB)
+AArch64 Linux uses either 3 levels or 4 levels of translation tables
+with the 4KB page configuration, allowing 39-bit (512GB) or 48-bit
+(256TB) virtual addresses, respectively, for both user and kernel. With
+64KB pages, only 2 levels of translation tables, allowing 42-bit (4TB)
virtual address, are used but the memory layout is the same.
-User addresses have bits 63:39 set to 0 while the kernel addresses have
+User addresses have bits 63:48 set to 0 while the kernel addresses have
the same bits set to 1. TTBRx selection is given by bit 63 of the
virtual address. The swapper_pg_dir contains only kernel (global)
mappings while the user pgd contains only user (non-global) mappings.
@@ -27,26 +26,7 @@ AArch64 Linux memory layout with 4KB pages + 3 levels:
Start End Size Use
-----------------------------------------------------------------------
0000000000000000 0000007fffffffff 512GB user
-
-ffffff8000000000 ffffffbbfffeffff ~240GB vmalloc
-
-ffffffbbffff0000 ffffffbbffffffff 64KB [guard page]
-
-ffffffbc00000000 ffffffbdffffffff 8GB vmemmap
-
-ffffffbe00000000 ffffffbffbbfffff ~8GB [guard, future vmmemap]
-
-ffffffbffa000000 ffffffbffaffffff 16MB PCI I/O space
-
-ffffffbffb000000 ffffffbffbbfffff 12MB [guard]
-
-ffffffbffbc00000 ffffffbffbdfffff 2MB fixed mappings
-
-ffffffbffbe00000 ffffffbffbffffff 2MB [guard]
-
-ffffffbffc000000 ffffffbfffffffff 64MB modules
-
-ffffffc000000000 ffffffffffffffff 256GB kernel logical memory map
+ffffff8000000000 ffffffffffffffff 512GB kernel
AArch64 Linux memory layout with 4KB pages + 4 levels:
@@ -54,26 +34,7 @@ AArch64 Linux memory layout with 4KB pages + 4 levels:
Start End Size Use
-----------------------------------------------------------------------
0000000000000000 0000ffffffffffff 256TB user
-
-ffff000000000000 ffff7bfffffeffff ~124TB vmalloc
-
-ffff7bffffff0000 ffff7bffffffffff 64KB [guard page]
-
-ffff7c0000000000 ffff7dffffffffff 2TB vmemmap
-
-ffff7e0000000000 ffff7ffffbbfffff ~2TB [guard, future vmmemap]
-
-ffff7ffffa000000 ffff7ffffaffffff 16MB PCI I/O space
-
-ffff7ffffb000000 ffff7ffffbbfffff 12MB [guard]
-
-ffff7ffffbc00000 ffff7ffffbdfffff 2MB fixed mappings
-
-ffff7ffffbe00000 ffff7ffffbffffff 2MB [guard]
-
-ffff7ffffc000000 ffff7fffffffffff 64MB modules
-
-ffff800000000000 ffffffffffffffff 128TB kernel logical memory map
+ffff000000000000 ffffffffffffffff 256TB kernel
AArch64 Linux memory layout with 64KB pages + 2 levels:
@@ -81,44 +42,14 @@ AArch64 Linux memory layout with 64KB pages + 2 levels:
Start End Size Use
-----------------------------------------------------------------------
0000000000000000 000003ffffffffff 4TB user
+fffffc0000000000 ffffffffffffffff 4TB kernel
-fffffc0000000000 fffffdfbfffeffff ~2TB vmalloc
-
-fffffdfbffff0000 fffffdfbffffffff 64KB [guard page]
-fffffdfc00000000 fffffdfdffffffff 8GB vmemmap
+For details of the virtual kernel memory layout please see the kernel
+booting log.
-fffffdfe00000000 fffffdfffbbfffff ~8GB [guard, future vmmemap]
-fffffdfffa000000 fffffdfffaffffff 16MB PCI I/O space
-
-fffffdfffb000000 fffffdfffbbfffff 12MB [guard]
-
-fffffdfffbc00000 fffffdfffbdfffff 2MB fixed mappings
-
-fffffdfffbe00000 fffffdfffbffffff 2MB [guard]
-
-fffffdfffc000000 fffffdffffffffff 64MB modules
-
-fffffe0000000000 ffffffffffffffff 2TB kernel logical memory map
-
-
-Translation table lookup with 4KB pages + 3 levels:
-
-+--------+--------+--------+--------+--------+--------+--------+--------+
-|63 56|55 48|47 40|39 32|31 24|23 16|15 8|7 0|
-+--------+--------+--------+--------+--------+--------+--------+--------+
- | | | | | |
- | | | | | v
- | | | | | [11:0] in-page offset
- | | | | +-> [20:12] L3 index
- | | | +-----------> [29:21] L2 index
- | | +---------------------> [38:30] L1 index
- | +-------------------------------> [47:39] L0 index (not used)
- +-------------------------------------------------> [63] TTBR0/1
-
-
-Translation table lookup with 4KB pages + 4 levels:
+Translation table lookup with 4KB pages:
+--------+--------+--------+--------+--------+--------+--------+--------+
|63 56|55 48|47 40|39 32|31 24|23 16|15 8|7 0|
@@ -133,7 +64,7 @@ Translation table lookup with 4KB pages + 4 levels:
+-------------------------------------------------> [63] TTBR0/1
-Translation table lookup with 64KB pages + 2 levels:
+Translation table lookup with 64KB pages:
+--------+--------+--------+--------+--------+--------+--------+--------+
|63 56|55 48|47 40|39 32|31 24|23 16|15 8|7 0|
@@ -142,10 +73,11 @@ Translation table lookup with 64KB pages + 2 levels:
| | | | v
| | | | [15:0] in-page offset
| | | +----------> [28:16] L3 index
- | | +--------------------------> [41:29] L2 index (only 38:29 used)
- | +-------------------------------> [47:42] L1 index (not used)
+ | | +--------------------------> [41:29] L2 index
+ | +-------------------------------> [47:42] L1 index
+-------------------------------------------------> [63] TTBR0/1
+
When using KVM, the hypervisor maps kernel pages in EL2, at a fixed
offset from the kernel VA (top 24bits of the kernel VA set to zero):
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 9f862e6e9286..ec82789d03c3 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -33,13 +33,16 @@
/*
* VMALLOC and SPARSEMEM_VMEMMAP ranges.
+ *
+ * VMEMAP_SIZE: allows the whole VA space to be covered by a struct page array
+ * (rounded up to PUD_SIZE).
+ * VMALLOC_START: beginning of the kernel VA space
+ * VMALLOC_END: extends to the available space below vmmemmap, PCI I/O space,
+ * fixed mappings and modules
*/
+#define VMEMMAP_SIZE ALIGN((1UL << (VA_BITS - PAGE_SHIFT)) * sizeof(struct page), PUD_SIZE)
#define VMALLOC_START (UL(0xffffffffffffffff) << VA_BITS)
-#if CONFIG_ARM64_PGTABLE_LEVELS != 4
-#define VMALLOC_END (PAGE_OFFSET - UL(0x400000000) - SZ_64K)
-#else
-#define VMALLOC_END (PAGE_OFFSET - UL(0x40000000000) - SZ_64K)
-#endif
+#define VMALLOC_END (PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K)
#define vmemmap ((struct page *)(VMALLOC_END + SZ_64K))
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 7f68804814a1..0b32504e280f 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -33,6 +33,7 @@
#include <linux/dma-mapping.h>
#include <linux/dma-contiguous.h>
+#include <asm/fixmap.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sizes.h>
@@ -256,26 +257,33 @@ void __init mem_init(void)
#define MLK(b, t) b, t, ((t) - (b)) >> 10
#define MLM(b, t) b, t, ((t) - (b)) >> 20
+#define MLG(b, t) b, t, ((t) - (b)) >> 30
#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
pr_notice("Virtual kernel memory layout:\n"
- " vmalloc : 0x%16lx - 0x%16lx (%6ld MB)\n"
+ " vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n"
#ifdef CONFIG_SPARSEMEM_VMEMMAP
- " vmemmap : 0x%16lx - 0x%16lx (%6ld MB)\n"
+ " vmemmap : 0x%16lx - 0x%16lx (%6ld GB maximum)\n"
+ " 0x%16lx - 0x%16lx (%6ld MB actual)\n"
#endif
+ " PCI I/O : 0x%16lx - 0x%16lx (%6ld MB)\n"
+ " fixed : 0x%16lx - 0x%16lx (%6ld KB)\n"
" modules : 0x%16lx - 0x%16lx (%6ld MB)\n"
" memory : 0x%16lx - 0x%16lx (%6ld MB)\n"
- " .init : 0x%p" " - 0x%p" " (%6ld kB)\n"
- " .text : 0x%p" " - 0x%p" " (%6ld kB)\n"
- " .data : 0x%p" " - 0x%p" " (%6ld kB)\n",
- MLM(VMALLOC_START, VMALLOC_END),
+ " .init : 0x%p" " - 0x%p" " (%6ld KB)\n"
+ " .text : 0x%p" " - 0x%p" " (%6ld KB)\n"
+ " .data : 0x%p" " - 0x%p" " (%6ld KB)\n",
+ MLG(VMALLOC_START, VMALLOC_END),
#ifdef CONFIG_SPARSEMEM_VMEMMAP
+ MLG((unsigned long)vmemmap,
+ (unsigned long)vmemmap + VMEMMAP_SIZE),
MLM((unsigned long)virt_to_page(PAGE_OFFSET),
(unsigned long)virt_to_page(high_memory)),
#endif
+ MLM((unsigned long)PCI_IOBASE, (unsigned long)PCI_IOBASE + SZ_16M),
+ MLK(FIXADDR_START, FIXADDR_TOP),
MLM(MODULES_VADDR, MODULES_END),
MLM(PAGE_OFFSET, (unsigned long)high_memory),
-
MLK_ROUNDUP(__init_begin, __init_end),
MLK_ROUNDUP(_text, _etext),
MLK_ROUNDUP(_sdata, _edata));
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-17 21:01:44 +0100