summaryrefslogtreecommitdiffstats
path: root/kernel/arch/x86/include/asm/alternative-asm.h
diff options
context:
space:
mode:
authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/x86/include/asm/alternative-asm.h
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/x86/include/asm/alternative-asm.h')
-rw-r--r--kernel/arch/x86/include/asm/alternative-asm.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/kernel/arch/x86/include/asm/alternative-asm.h b/kernel/arch/x86/include/asm/alternative-asm.h
new file mode 100644
index 000000000..bdf02eeee
--- /dev/null
+++ b/kernel/arch/x86/include/asm/alternative-asm.h
@@ -0,0 +1,82 @@
+#ifndef _ASM_X86_ALTERNATIVE_ASM_H
+#define _ASM_X86_ALTERNATIVE_ASM_H
+
+#ifdef __ASSEMBLY__
+
+#include <asm/asm.h>
+
+#ifdef CONFIG_SMP
+ .macro LOCK_PREFIX
+672: lock
+ .pushsection .smp_locks,"a"
+ .balign 4
+ .long 672b - .
+ .popsection
+ .endm
+#else
+ .macro LOCK_PREFIX
+ .endm
+#endif
+
+.macro altinstruction_entry orig alt feature orig_len alt_len pad_len
+ .long \orig - .
+ .long \alt - .
+ .word \feature
+ .byte \orig_len
+ .byte \alt_len
+ .byte \pad_len
+.endm
+
+.macro ALTERNATIVE oldinstr, newinstr, feature
+140:
+ \oldinstr
+141:
+ .skip -(((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)),0x90
+142:
+
+ .pushsection .altinstructions,"a"
+ altinstruction_entry 140b,143f,\feature,142b-140b,144f-143f,142b-141b
+ .popsection
+
+ .pushsection .altinstr_replacement,"ax"
+143:
+ \newinstr
+144:
+ .popsection
+.endm
+
+#define old_len 141b-140b
+#define new_len1 144f-143f
+#define new_len2 145f-144f
+
+/*
+ * max without conditionals. Idea adapted from:
+ * http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax
+ */
+#define alt_max_short(a, b) ((a) ^ (((a) ^ (b)) & -(-((a) < (b)))))
+
+.macro ALTERNATIVE_2 oldinstr, newinstr1, feature1, newinstr2, feature2
+140:
+ \oldinstr
+141:
+ .skip -((alt_max_short(new_len1, new_len2) - (old_len)) > 0) * \
+ (alt_max_short(new_len1, new_len2) - (old_len)),0x90
+142:
+
+ .pushsection .altinstructions,"a"
+ altinstruction_entry 140b,143f,\feature1,142b-140b,144f-143f,142b-141b
+ altinstruction_entry 140b,144f,\feature2,142b-140b,145f-144f,142b-141b
+ .popsection
+
+ .pushsection .altinstr_replacement,"ax"
+143:
+ \newinstr1
+144:
+ \newinstr2
+145:
+ .popsection
+.endm
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_X86_ALTERNATIVE_ASM_H */