[tip:core/memblock] x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S

tip-bot for Jeremy Fitzhardinge
2010-10-14T00:32:07Z

Commit-ID: 859ee4f57fb4e91de8439496f62eb996f4a28ca8
Gitweb: http://git.kernel.org/tip/859ee4f57fb4e91de8439496f62eb996f4a28ca8
Author: Jeremy Fitzhardinge <jeremy@goop.org>
AuthorDate: Wed, 13 Oct 2010 16:34:15 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Wed, 13 Oct 2010 17:09:59 -0700

x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S

head_64.S maps up to 512 MiB, but that is not necessarity true for
other entry paths, such as Xen.

Thus, co-locate the setting of max_pfn_mapped with the code to
actually set up the page tables in head_64.S. The 32-bit code is
already so co-located. (The Xen code already sets max_pfn_mapped
correctly for its own use case.)

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
LKML-Reference: <4CB641F7.9040103@goop.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/kernel/head_64.S | 2 ++
arch/x86/kernel/setup.c | 1 -
2 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 239046b..b75c6f4 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -141,6 +141,8 @@ ident_complete:
addq %rbp, trampoline_level4_pgt + (511*8)(%rip)
#endif

+ movq $KERNEL_IMAGE_SIZE / PAGE_SIZE, max_pfn_mapped(%rip)
+
/* Due to ENTRY(), sometimes the empty space gets filled with
* zeros. Better take a jmp than relying on empty space being
* filled with 0x90 (nop)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index b11a238..c3cebfe 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -932,7 +932,6 @@ void __init setup_arch(char **cmdline_p)
max_low_pfn = max_pfn;

high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
- max_pfn_mapped = KERNEL_IMAGE_SIZE >> PAGE_SHIFT;
#endif

/*