From e4877d64f00964d86a6e4a023011cccc73899018 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 18 Sep 2015 20:23:34 +0200 Subject: x86/fpu/math-emu: Add support for FISTTP instructions These FPU instructions were added in SSE3-enabled CPUs. Run-tested by booting with "no387 nofxsr" and running test program: [RUN] Testing fisttp instructions [OK] fisttp Signed-off-by: Denys Vlasenko Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Shuah Khan Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1442600614-28428-1-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/math-emu/load_store.c | 63 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 51 insertions(+), 12 deletions(-) (limited to 'arch/x86/math-emu') diff --git a/arch/x86/math-emu/load_store.c b/arch/x86/math-emu/load_store.c index 2931ff355218..95228ff042c0 100644 --- a/arch/x86/math-emu/load_store.c +++ b/arch/x86/math-emu/load_store.c @@ -33,11 +33,12 @@ #define pop_0() { FPU_settag0(TAG_Empty); top++; } +/* index is a 5-bit value: (3-bit FPU_modrm.reg field | opcode[2,1]) */ static u_char const type_table[32] = { - _PUSH_, _PUSH_, _PUSH_, _PUSH_, - _null_, _null_, _null_, _null_, - _REG0_, _REG0_, _REG0_, _REG0_, - _REG0_, _REG0_, _REG0_, _REG0_, + _PUSH_, _PUSH_, _PUSH_, _PUSH_, /* /0: d9:fld f32, db:fild m32, dd:fld f64, df:fild m16 */ + _null_, _REG0_, _REG0_, _REG0_, /* /1: d9:undef, db,dd,df:fisttp m32/64/16 */ + _REG0_, _REG0_, _REG0_, _REG0_, /* /2: d9:fst f32, db:fist m32, dd:fst f64, df:fist m16 */ + _REG0_, _REG0_, _REG0_, _REG0_, /* /3: d9:fstp f32, db:fistp m32, dd:fstp f64, df:fistp m16 */ _NONE_, _null_, _NONE_, _PUSH_, _NONE_, _PUSH_, _null_, _PUSH_, _NONE_, _null_, _NONE_, _REG0_, @@ -45,15 +46,19 @@ static u_char const type_table[32] = { }; u_char const data_sizes_16[32] = { - 4, 4, 8, 2, 0, 0, 0, 0, - 4, 4, 8, 2, 4, 4, 8, 2, + 4, 4, 8, 2, + 0, 4, 8, 2, /* /1: d9:undef, db,dd,df:fisttp */ + 4, 4, 8, 2, + 4, 4, 8, 2, 14, 0, 94, 10, 2, 10, 0, 8, 14, 0, 94, 10, 2, 10, 2, 8 }; static u_char const data_sizes_32[32] = { - 4, 4, 8, 2, 0, 0, 0, 0, - 4, 4, 8, 2, 4, 4, 8, 2, + 4, 4, 8, 2, + 0, 4, 8, 2, /* /1: d9:undef, db,dd,df:fisttp */ + 4, 4, 8, 2, + 4, 4, 8, 2, 28, 0, 108, 10, 2, 10, 0, 8, 28, 0, 108, 10, 2, 10, 2, 8 }; @@ -65,6 +70,7 @@ int FPU_load_store(u_char type, fpu_addr_modes addr_modes, FPU_REG *st0_ptr; u_char st0_tag = TAG_Empty; /* This is just to stop a gcc warning. */ u_char loaded_tag; + int sv_cw; st0_ptr = NULL; /* Initialized just to stop compiler warnings. */ @@ -111,7 +117,8 @@ int FPU_load_store(u_char type, fpu_addr_modes addr_modes, } switch (type) { - case 000: /* fld m32real */ + /* type is a 5-bit value: (3-bit FPU_modrm.reg field | opcode[2,1]) */ + case 000: /* fld m32real (d9 /0) */ clear_C1(); loaded_tag = FPU_load_single((float __user *)data_address, &loaded_data); @@ -123,13 +130,13 @@ int FPU_load_store(u_char type, fpu_addr_modes addr_modes, } FPU_copy_to_reg0(&loaded_data, loaded_tag); break; - case 001: /* fild m32int */ + case 001: /* fild m32int (db /0) */ clear_C1(); loaded_tag = FPU_load_int32((long __user *)data_address, &loaded_data); FPU_copy_to_reg0(&loaded_data, loaded_tag); break; - case 002: /* fld m64real */ + case 002: /* fld m64real (dd /0) */ clear_C1(); loaded_tag = FPU_load_double((double __user *)data_address, @@ -142,12 +149,44 @@ int FPU_load_store(u_char type, fpu_addr_modes addr_modes, } FPU_copy_to_reg0(&loaded_data, loaded_tag); break; - case 003: /* fild m16int */ + case 003: /* fild m16int (df /0) */ clear_C1(); loaded_tag = FPU_load_int16((short __user *)data_address, &loaded_data); FPU_copy_to_reg0(&loaded_data, loaded_tag); break; + /* case 004: undefined (d9 /1) */ + /* fisttp are enabled if CPUID(1).ECX(0) "sse3" is set */ + case 005: /* fisttp m32int (db /1) */ + clear_C1(); + sv_cw = control_word; + control_word |= RC_CHOP; + if (FPU_store_int32 + (st0_ptr, st0_tag, (long __user *)data_address)) + pop_0(); /* pop only if the number was actually stored + (see the 80486 manual p16-28) */ + control_word = sv_cw; + break; + case 006: /* fisttp m64int (dd /1) */ + clear_C1(); + sv_cw = control_word; + control_word |= RC_CHOP; + if (FPU_store_int64 + (st0_ptr, st0_tag, (long long __user *)data_address)) + pop_0(); /* pop only if the number was actually stored + (see the 80486 manual p16-28) */ + control_word = sv_cw; + break; + case 007: /* fisttp m16int (df /1) */ + clear_C1(); + sv_cw = control_word; + control_word |= RC_CHOP; + if (FPU_store_int16 + (st0_ptr, st0_tag, (short __user *)data_address)) + pop_0(); /* pop only if the number was actually stored + (see the 80486 manual p16-28) */ + control_word = sv_cw; + break; case 010: /* fst m32real */ clear_C1(); FPU_store_single(st0_ptr, st0_tag, -- cgit v1.2.3