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authorZachary Amsden <zach@vmware.com>2006-01-06 03:11:50 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-06 11:33:34 -0500
commitff6e8c0d5e47f0ceeebde86ec2f5919dbd5beb67 (patch)
treef7e50b5962b7b38ca025c0bf9ee48b618424cc6b /include
parenteb05c3249a8e8a675e79d221f4a0874dc10ec903 (diff)
[PATCH] x86: Cr4 is valid on some 486s
So some 486 processors do have CR4 register. Allow them to present it in register dumps by using the old fault technique rather than testing processor family. Thanks to Maciej for noticing this. Signed-off-by: Zachary Amsden <zach@vmware.com> Cc: "Seth, Rohit" <rohit.seth@intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include')
-rw-r--r--include/asm-i386/system.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/include/asm-i386/system.h b/include/asm-i386/system.h
index 772f85da1206..88b4d5c6f37a 100644
--- a/include/asm-i386/system.h
+++ b/include/asm-i386/system.h
@@ -140,6 +140,19 @@ static inline unsigned long _get_base(char * addr)
140 :"=r" (__dummy)); \ 140 :"=r" (__dummy)); \
141 __dummy; \ 141 __dummy; \
142}) 142})
143
144#define read_cr4_safe() ({ \
145 unsigned int __dummy; \
146 /* This could fault if %cr4 does not exist */ \
147 __asm__("1: movl %%cr4, %0 \n" \
148 "2: \n" \
149 ".section __ex_table,\"a\" \n" \
150 ".long 1b,2b \n" \
151 ".previous \n" \
152 : "=r" (__dummy): "0" (0)); \
153 __dummy; \
154})
155
143#define write_cr4(x) \ 156#define write_cr4(x) \
144 __asm__ __volatile__("movl %0,%%cr4": :"r" (x)); 157 __asm__ __volatile__("movl %0,%%cr4": :"r" (x));
145#define stts() write_cr0(8 | read_cr0()) 158#define stts() write_cr0(8 | read_cr0())