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| author | Borislav Petkov <bp@suse.de> | 2018-12-10 18:17:23 +0300 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2019-01-16 14:42:50 +0300 |
| commit | 71a93c26930471e976dd184ef91931b2a5393afc (patch) | |
| tree | 27b0c88758216024db98201f36c5e706211bb209 | |
| parent | c1d4e4192aa4e7408a81c32a77e7c867a07f8aa2 (diff) | |
| download | linux-71a93c26930471e976dd184ef91931b2a5393afc.tar.xz | |
x86/alternatives: Add an ALTERNATIVE_3() macro
Similar to ALTERNATIVE_2(), ALTERNATIVE_3() selects between 3 possible
variants. Will be used for adding RDTSCP to the rdtsc_ordered()
alternatives.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: X86 ML <x86@kernel.org>
Link: https://lkml.kernel.org/r/20181211222326.14581-4-bp@alien8.de
| -rw-r--r-- | arch/x86/include/asm/alternative.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index 373e2baca6ce..4c74073a19cc 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -122,6 +122,16 @@ static inline int alternatives_text_reserved(void *start, void *end) "(" alt_max_short(alt_rlen(num1), alt_rlen(num2)) " - (" alt_slen ")), 0x90\n" \ alt_end_marker ":\n" +#define OLDINSTR_3(oldinsn, n1, n2, n3) \ + "# ALT: oldinstr3\n" \ + "661:\n\t" oldinsn "\n662:\n" \ + "# ALT: padding3\n" \ + ".skip -((" alt_max_short(alt_max_short(alt_rlen(n1), alt_rlen(n2)), alt_rlen(n3)) \ + " - (" alt_slen ")) > 0) * " \ + "(" alt_max_short(alt_max_short(alt_rlen(n1), alt_rlen(n2)), alt_rlen(n3)) \ + " - (" alt_slen ")), 0x90\n" \ + alt_end_marker ":\n" + #define ALTINSTR_ENTRY(feature, num) \ " .long 661b - .\n" /* label */ \ " .long " b_replacement(num)"f - .\n" /* new instruction */ \ @@ -155,6 +165,19 @@ static inline int alternatives_text_reserved(void *start, void *end) ALTINSTR_REPLACEMENT(newinstr2, feature2, 2) \ ".popsection\n" +#define ALTERNATIVE_3(oldinsn, newinsn1, feat1, newinsn2, feat2, newinsn3, feat3) \ + OLDINSTR_3(oldinsn, 1, 2, 3) \ + ".pushsection .altinstructions,\"a\"\n" \ + ALTINSTR_ENTRY(feat1, 1) \ + ALTINSTR_ENTRY(feat2, 2) \ + ALTINSTR_ENTRY(feat3, 3) \ + ".popsection\n" \ + ".pushsection .altinstr_replacement, \"ax\"\n" \ + ALTINSTR_REPLACEMENT(newinsn1, feat1, 1) \ + ALTINSTR_REPLACEMENT(newinsn2, feat2, 2) \ + ALTINSTR_REPLACEMENT(newinsn3, feat3, 3) \ + ".popsection\n" + /* * Alternative instructions for different CPU types or capabilities. * |