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authorIngo Molnar <mingo@elte.hu>2008-01-30 13:33:48 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:33:48 +0100
commitd701fda8601fe267fbd3648f108f0e751305101b (patch)
treeed4e32e3ff33eb9e01a4c8321776b82b834c6fce /include/asm-x86/fixmap_32.h
parentd690b2afd5a7a02816386aa704c8c0b1aca8d2de (diff)
x86: fix early_ioremap()/btmap
fix a long-standing weakness of the early-ioremap allocator: it uses a single pgd entry for the boot mappings, and was not properly protecting itself against crossing a 2MB (4MB) boundary. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/asm-x86/fixmap_32.h')
-rw-r--r--include/asm-x86/fixmap_32.h12
1 files changed, 10 insertions, 2 deletions
diff --git a/include/asm-x86/fixmap_32.h b/include/asm-x86/fixmap_32.h
index 46bedb7b542..fde140fd6d9 100644
--- a/include/asm-x86/fixmap_32.h
+++ b/include/asm-x86/fixmap_32.h
@@ -90,10 +90,18 @@ enum fixed_addresses {
FIX_PARAVIRT_BOOTMAP,
#endif
__end_of_permanent_fixed_addresses,
- /* temporary boot-time mappings, used before ioremap() is functional */
+ /*
+ * 256 temporary boot-time mappings, used by early_ioremap(),
+ * before ioremap() is functional.
+ *
+ * We round it up to the next 512 pages boundary so that we
+ * can have a single pgd entry and a single pte table:
+ */
#define NR_FIX_BTMAPS 64
#define FIX_BTMAPS_NESTING 4
- FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
+ FIX_BTMAP_END =
+ __end_of_permanent_fixed_addresses + 512 -
+ (__end_of_permanent_fixed_addresses & 511),
FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS*FIX_BTMAPS_NESTING - 1,
FIX_WP_TEST,
__end_of_fixed_addresses