arm64: Determine the vmalloc/vmemmap space at build time based on VA_BITS

Rather than guessing what the maximum vmmemap space should be, this
patch allows the calculation based on the VA_BITS and sizeof(struct
page). The vmalloc space extends to the beginning of the vmemmap space.

Since the virtual kernel memory layout now depends on the build
configuration, this patch removes the detailed description in
Documentation/arm64/memory.txt in favour of information printed during
kernel booting.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Jungseok Lee <jungseoklee85@gmail.com>

diff --git a/Documentation/arm64/memory.txt b/Documentation/arm64/memory.txt
index 4c720d698e8e0b262abf604e389c1c976bde9b2e..8845d0847a66960374a7d043bbba78fb4b47d313 100644 (file)
--- 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 9f862e6e9286bf0b28faed022fd41fa5c626f7ed..ec82789d03c3ac58f3db65e3171af772d59dd763 100644 (file)
--- 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 7f68804814a1bc5ab7959e3d921f27bfc5cfa2f8..0b32504e280f1a04592305750ccca2c388e5e120 100644 (file)
--- 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));