On 08/22/2015 10:54 AM, Ingo Molnar wrote: > > * Denys Vlasenko <[email protected]> wrote: > >> +/* fcmovCC and f(u)comi(p) are enabled if CPUID(1).EDX(15) "cmov" is set */ >> + >> static FUNC const st_instr_table[64] = { >> - fadd__, fld_i_, __BAD__, __BAD__, fadd_i, ffree_, faddp_, _df_c0_, >> - fmul__, fxch_i, __BAD__, __BAD__, fmul_i, _dd_c8_, fmulp_, _df_c8_, >> - fcom_st, fp_nop, __BAD__, __BAD__, _dc_d0_, fst_i_, _de_d0_, _df_d0_, >> - fcompst, _d9_d8_, __BAD__, __BAD__, _dc_d8_, fstp_i, fcompp, _df_d8_, >> + fadd__, fld_i_, fcmovb, fcmovnb, fadd_i, ffree_, faddp_, >> _df_c0_, >> + fmul__, fxch_i, fcmove, fcmovne, fmul_i, _dd_c8_, fmulp_, >> _df_c8_, >> + fcom_st, fp_nop, fcmovbe, fcmovnbe, _dc_d0_, fst_i_, _de_d0_, >> _df_d0_, >> + fcompst, _d9_d8_, fcmovu, fcmovnu, _dc_d8_, fstp_i, fcompp, >> _df_d8_, >> fsub__, FPU_etc, __BAD__, finit_, fsubri, fucom_, fsubrp, fstsw_, >> - fsubr_, fconst, fucompp, __BAD__, fsub_i, fucomp, fsubp_, __BAD__, >> - fdiv__, FPU_triga, __BAD__, __BAD__, fdivri, __BAD__, fdivrp, __BAD__, >> + fsubr_, fconst, fucompp, fucomi_, fsub_i, fucomp, fsubp_, >> fucomip, >> + fdiv__, FPU_triga, __BAD__, fcomi_, fdivri, __BAD__, fdivrp, fcomip, >> fdivr_, FPU_trigb, __BAD__, __BAD__, fdiv_i, __BAD__, fdivp_, __BAD__, >> }; > > So the problem is that you did not give an FPU register encoding type table > entry > for the new opcodes: > > static u_char const type_table[64] = { > _REGI_, _NONE_, _null_, _null_, _REGIi, _REGi_, _REGIp, _REGi_, > _REGI_, _REGIn, _null_, _null_, _REGIi, _REGI_, _REGIp, _REGI_, > _REGIc, _NONE_, _null_, _null_, _REGIc, _REG0_, _REGIc, _REG0_, > _REGIc, _REG0_, _null_, _null_, _REGIc, _REG0_, _REGIc, _REG0_, > _REGI_, _NONE_, _null_, _NONE_, _REGIi, _REGIc, _REGIp, _NONE_, > _REGI_, _NONE_, _REGIc, _null_, _REGIi, _REGIc, _REGIp, _null_, > _REGI_, _NONE_, _null_, _null_, _REGIi, _null_, _REGIp, _null_, > _REGI_, _NONE_, _null_, _null_, _REGIi, _null_, _REGIp, _null_ > }; > > Those _null_ entries must be filled in as well. > > For FUCOMI[P] it's _REGIc I think, so I tried that - and the patch below on > top of > yours made those instructions appear to work - only to be caught in an MMX op: > > 0xb75eb3fb <bn_mul_add_words+59>: movd %ebp,%mm0 > > > > :-/ > > Arguably the way I tested it, user-space libraries see SSE and MMX > capabilities: > > flags : vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov > pat > pse36 clflush mmx sse2 ht syscall nx mmxext lm 3dnowext 3dnow rep_good pni > lahf_lm > cmp_legacy 3dnowprl... > > So I'll first turn those CPUID bits off, to (hopefully) not confuse > user-space. > > Thanks, > > Ingo > > ====================> > > arch/x86/math-emu/fpu_entry.c | 82 > ++++++++++++++----------------------------- > 1 file changed, 27 insertions(+), 55 deletions(-) > > diff --git a/arch/x86/math-emu/fpu_entry.c b/arch/x86/math-emu/fpu_entry.c > index d20c8f8420e2..4d91c0fc6bc3 100644 > --- a/arch/x86/math-emu/fpu_entry.c > +++ b/arch/x86/math-emu/fpu_entry.c > @@ -40,12 +40,10 @@ > > #define __BAD__ FPU_illegal /* Illegal on an 80486, causes SIGILL */ > > -#ifndef NO_UNDOC_CODE /* Un-documented FPU op-codes supported > by default. */ > - > -/* WARNING: These codes are not documented by Intel in their 80486 manual > +/* WARNING: These codes are not all documented by Intel in their 80486 manual > and may not work on FPU clones or later Intel FPUs. */ > > -/* Changes to support the un-doc codes provided by Linus Torvalds. */ > +/* Changes to support the un-documented instructions provided by Linus > Torvalds. */ > > #define _d9_d8_ fstp_i /* unofficial code (19) */ > #define _dc_d0_ fcom_st /* unofficial code (14) */ > @@ -60,31 +58,24 @@ > /* fcmovCC and f(u)comi(p) are enabled if CPUID(1).EDX(15) "cmov" is set */ > > static FUNC const st_instr_table[64] = { > - fadd__, fld_i_, fcmovb, fcmovnb, fadd_i, ffree_, faddp_, > _df_c0_, > - fmul__, fxch_i, fcmove, fcmovne, fmul_i, _dd_c8_, fmulp_, > _df_c8_, > - fcom_st, fp_nop, fcmovbe, fcmovnbe, _dc_d0_, fst_i_, _de_d0_, > _df_d0_, > - fcompst, _d9_d8_, fcmovu, fcmovnu, _dc_d8_, fstp_i, fcompp, > _df_d8_, > - fsub__, FPU_etc, __BAD__, finit_, fsubri, fucom_, fsubrp, fstsw_, > - fsubr_, fconst, fucompp, fucomi_, fsub_i, fucomp, fsubp_, > fucomip, > - fdiv__, FPU_triga, __BAD__, fcomi_, fdivri, __BAD__, fdivrp, fcomip, > - fdivr_, FPU_trigb, __BAD__, __BAD__, fdiv_i, __BAD__, fdivp_, __BAD__, > +/* 0x00 */ fadd__, fld_i_, fcmovb, fcmovnb, > +/* 0x04 */ fadd_i, ffree_, faddp_, _df_c0_, > +/* 0x08 */ fmul__, fxch_i, fcmove, fcmovne, > +/* 0x0c */ fmul_i, _dd_c8_, fmulp_, _df_c8_, > +/* 0x10 */ fcom_st, fp_nop, fcmovbe, fcmovnbe, > +/* 0x14 */ _dc_d0_, fst_i_, _de_d0_, _df_d0_, > +/* 0x18 */ fcompst, _d9_d8_, fcmovu, fcmovnu, > +/* 0x1c */ _dc_d8_, fstp_i, fcompp, _df_d8_, > +/* 0x20 */ fsub__, FPU_etc, __BAD__, finit_, > +/* 0x24 */ fsubri, fucom_, fsubrp, fstsw_, > +/* 0x28 */ fsubr_, fconst, fucompp, fucomi_, > +/* 0x2c */ fsub_i, fucomp, fsubp_, fucomip, > +/* 0x30 */ fdiv__, FPU_triga, __BAD__, fcomi_, > +/* 0x34 */ fdivri, __BAD__, fdivrp, fcomip, > +/* 0x38 */ fdivr_, FPU_trigb, __BAD__, __BAD__, > +/* 0x3c */ fdiv_i, __BAD__, fdivp_, __BAD__,
The numeric comments added at the left don't look correct. In this table, each _column_ corresponds to one 0xd? opcode. Each row corresponds to a group of mod-reg-rm bytes with only "rm" field chnaging. (These insns act on registers, not memory, and "rm" value encodes register number, st(i).) Something like this: /*Opcode: d8 d9 da db dc dd de df */ /*c0..7*/ fadd__, fld_i_, fcmovb, fcmovnb, fadd_i, ffree_, faddp_, _df_c0_, /*c8..f*/ fmul__, fxch_i, fcmove, fcmovne, fmul_i, _dd_c8_,fmulp_, _df_c8_, /*d0..7*/ fcom_st,fp_nop, fcmovbe,fcmovnbe,_dc_d0_,fst_i_, _de_d0_,_df_d0_, /*d8..f*/ fcompst,_d9_d8_, fcmovu, fcmovnu, _dc_d8_,fstp_i, fcompp, _df_d8_, /*e0..7*/ fsub__, FPU_etc, __BAD__,finit_, fsubri, fucom_, fsubrp, fstsw_, /*e8..f*/ fsubr_, fconst, fucompp,fucomi_, fsub_i, fucomp, fsubp_, fucomip, /*f0..7*/ fdiv__, FPU_triga,__BAD__,fcomi_, fdivri, __BAD__,fdivrp, fcomip, /*f8..f*/ fdivr_, FPU_trigb,__BAD__,__BAD__, fdiv_i, __BAD__,fdivp_, __BAD__, They should be: -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
