path: root/Documentation/x86/x86_64
diff options
authorRik van Riel <riel@redhat.com>2009-05-05 17:28:56 -0400
committerH. Peter Anvin <hpa@zytor.com>2009-05-05 19:10:18 -0700
commitc898faf91b3ec6b0f6efa35831b3984fa3331db0 (patch)
tree5fa6850127cfe510e1e2d45b6c80044e29a137f5 /Documentation/x86/x86_64
parenta454ab3110175d710f4f9a96226a26ce4d5d5de2 (diff)
x86: 46 bit physical address support on 64 bits
Extend the maximum addressable memory on x86-64 from 2^44 to 2^46 bytes. This requires some shuffling around of the vmalloc and virtual memmap memory areas, to keep them away from the direct mapping of up to 64TB of physical memory. This patch also introduces a guard hole between the vmalloc area and the virtual memory map space. There's really no good reason why we wouldn't have a guard hole there. [ Impact: future hardware enablement ] Signed-off-by: Rik van Riel <riel@redhat.com> LKML-Reference: <20090505172856.6820db22@cuia.bos.redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'Documentation/x86/x86_64')
1 files changed, 5 insertions, 4 deletions
diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt
index 29b52b14d0b4..539413235845 100644
--- a/Documentation/x86/x86_64/mm.txt
+++ b/Documentation/x86/x86_64/mm.txt
@@ -6,10 +6,11 @@ Virtual memory map with 4 level page tables:
0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm
hole caused by [48:63] sign extension
ffff800000000000 - ffff80ffffffffff (=40 bits) guard hole
-ffff880000000000 - ffffc0ffffffffff (=57 TB) direct mapping of all phys. memory
-ffffc10000000000 - ffffc1ffffffffff (=40 bits) hole
-ffffc20000000000 - ffffe1ffffffffff (=45 bits) vmalloc/ioremap space
-ffffe20000000000 - ffffe2ffffffffff (=40 bits) virtual memory map (1TB)
+ffff880000000000 - ffffc8ffffffffff (=64 TB) direct mapping of all phys. memory
+ffffc80000000000 - ffffc8ffffffffff (=40 bits) hole
+ffffc90000000000 - ffffe8ffffffffff (=45 bits) vmalloc/ioremap space
+ffffe90000000000 - ffffe9ffffffffff (=40 bits) hole
+ffffea0000000000 - ffffeaffffffffff (=40 bits) virtual memory map (1TB)
... unused hole ...
ffffffff80000000 - ffffffffa0000000 (=512 MB) kernel text mapping, from phys 0
ffffffffa0000000 - fffffffffff00000 (=1536 MB) module mapping space

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