From: Borislav Petkov <[email protected]> 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 <[email protected]> --- arch/x86/include/asm/alternative.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index 8d38b296a18a..f24d111f366b 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -115,6 +115,16 @@ 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 */ \ @@ -148,6 +158,19 @@ 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. * -- 2.19.1
