Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9a9d8642 authored by Denys Vlasenko's avatar Denys Vlasenko Committed by Ingo Molnar
Browse files

x86/fpu/math-emu: Add support for FCMOVcc insns 



Run-tested by booting with "no387 nofxsr" and running test
program:

  [RUN]   Testing fcmovCC instructions
  [OK]    fcmovCC

Signed-off-by: default avatarDenys Vlasenko <dvlasenk@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1442588010-20055-3-git-send-email-dvlasenk@redhat.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent b8e4a910

arch/x86/math-emu/fpu_aux.c

+70 −0
Original line number Diff line number Diff line
@@ -169,6 +169,76 @@ void fxch_i(void) 
	fpu_tag_word = tag_word;

}



static void fcmovCC(void)

{

	/* fcmovCC st(i) */

	int i = FPU_rm;

	FPU_REG *st0_ptr = &st(0);

	FPU_REG *sti_ptr = &st(i);

	long tag_word = fpu_tag_word;

	int regnr = top & 7;

	int regnri = (top + i) & 7;

	u_char sti_tag = (tag_word >> (regnri * 2)) & 3;



	if (sti_tag == TAG_Empty) {

		FPU_stack_underflow();

		clear_C1();

		return;

	}

	reg_copy(sti_ptr, st0_ptr);

	tag_word &= ~(3 << (regnr * 2));

	tag_word |= (sti_tag << (regnr * 2));

	fpu_tag_word = tag_word;

}



void fcmovb(void)

{

	if (FPU_EFLAGS & X86_EFLAGS_CF)

		fcmovCC();

}



void fcmove(void)

{

	if (FPU_EFLAGS & X86_EFLAGS_ZF)

		fcmovCC();

}



void fcmovbe(void)

{

	if (FPU_EFLAGS & (X86_EFLAGS_CF|X86_EFLAGS_ZF))

		fcmovCC();

}



void fcmovu(void)

{

	if (FPU_EFLAGS & X86_EFLAGS_PF)

		fcmovCC();

}



void fcmovnb(void)

{

	if (!(FPU_EFLAGS & X86_EFLAGS_CF))

		fcmovCC();

}



void fcmovne(void)

{

	if (!(FPU_EFLAGS & X86_EFLAGS_ZF))

		fcmovCC();

}



void fcmovnbe(void)

{

	if (!(FPU_EFLAGS & (X86_EFLAGS_CF|X86_EFLAGS_ZF)))

		fcmovCC();

}



void fcmovnu(void)

{

	if (!(FPU_EFLAGS & X86_EFLAGS_PF))

		fcmovCC();

}



void ffree_(void)

{

	/* ffree st(i) */

arch/x86/math-emu/fpu_entry.c

+9 −9
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ 


#define __BAD__ FPU_illegal	/* Illegal on an 80486, causes SIGILL */



/* f(u)comi(p) are enabled if CPUID(1).EDX(15) "cmov" is set */

/* fcmovCC and f(u)comi(p) are enabled if CPUID(1).EDX(15) "cmov" is set */



/* WARNING: "u" entries are not documented by Intel in their 80486 manual

   and may not work on FPU clones or later Intel FPUs.
@@ -49,13 +49,13 @@ 
static FUNC const st_instr_table[64] = {

/* Opcode:	d8		d9		da		db */

/*		dc		dd		de		df */

/* c0..7 */	fadd__,		fld_i_,		__BAD__,	__BAD__,

/* c0..7 */	fadd__,		fld_i_,		fcmovb,		fcmovnb,

/* c0..7 */	fadd_i,		ffree_,		faddp_,		ffreep,/*u*/

/* c8..f */	fmul__,		fxch_i,		__BAD__,	__BAD__,

/* c8..f */	fmul__,		fxch_i,		fcmove,		fcmovne,

/* c8..f */	fmul_i,		fxch_i,/*u*/	fmulp_,		fxch_i,/*u*/

/* d0..7 */	fcom_st,	fp_nop,		__BAD__,	__BAD__,

/* d0..7 */	fcom_st,	fp_nop,		fcmovbe,	fcmovnbe,

/* d0..7 */	fcom_st,/*u*/	fst_i_,		fcompst,/*u*/	fstp_i,/*u*/

/* d8..f */	fcompst,	fstp_i,/*u*/	__BAD__,	__BAD__,

/* d8..f */	fcompst,	fstp_i,/*u*/	fcmovu,		fcmovnu,

/* d8..f */	fcompst,/*u*/	fstp_i,		fcompp,		fstp_i,/*u*/

/* e0..7 */	fsub__,		FPU_etc,	__BAD__,	finit_,

/* e0..7 */	fsubri,		fucom_,		fsubrp,		fstsw_,
@@ -80,10 +80,10 @@ static FUNC const st_instr_table[64] = { 


static u_char const type_table[64] = {

/* Opcode:	d8	d9	da	db	dc	dd	de	df */

/* c0..7 */	_REGI_, _NONE_, _null_, _null_, _REGIi, _REGi_, _REGIp, _REGi_,

/* c8..f */	_REGI_, _REGIn, _null_, _null_, _REGIi, _REGI_, _REGIp, _REGI_,

/* d0..7 */	_REGIc, _NONE_, _null_, _null_, _REGIc, _REG0_, _REGIc, _REG0_,

/* d8..f */	_REGIc, _REG0_, _null_, _null_, _REGIc, _REG0_, _REGIc, _REG0_,

/* c0..7 */	_REGI_, _NONE_, _REGIn, _REGIn, _REGIi, _REGi_, _REGIp, _REGi_,

/* c8..f */	_REGI_, _REGIn, _REGIn, _REGIn, _REGIi, _REGI_, _REGIp, _REGI_,

/* d0..7 */	_REGIc, _NONE_, _REGIn, _REGIn, _REGIc, _REG0_, _REGIc, _REG0_,

/* d8..f */	_REGIc, _REG0_, _REGIn, _REGIn, _REGIc, _REG0_, _REGIc, _REG0_,

/* e0..7 */	_REGI_, _NONE_, _null_, _NONE_, _REGIi, _REGIc, _REGIp, _NONE_,

/* e8..f */	_REGI_, _NONE_, _REGIc, _REGIc, _REGIi, _REGIc, _REGIp, _REGIc,

/* f0..7 */	_REGI_, _NONE_, _null_, _REGIc, _REGIi, _null_, _REGIp, _REGIc,

arch/x86/math-emu/fpu_proto.h

+8 −0
Original line number Diff line number Diff line
@@ -46,6 +46,14 @@ extern void fstsw_(void); 
extern void fp_nop(void);

extern void fld_i_(void);

extern void fxch_i(void);

extern void fcmovb(void);

extern void fcmove(void);

extern void fcmovbe(void);

extern void fcmovu(void);

extern void fcmovnb(void);

extern void fcmovne(void);

extern void fcmovnbe(void);

extern void fcmovnu(void);

extern void ffree_(void);

extern void ffreep(void);

extern void fst_i_(void);