3.1.7 branch.

kernel/arch/i386/arch_system.c

@@ -11,6 +11,10 @@
 #include <minix/cpufeature.h>
 #include <a.out.h>
 #include <assert.h>
+#include <signal.h>
+#include <machine/vm.h>
+
+#include <sys/sigcontext.h>
 
 #include "archconst.h"
 #include "proto.h"
@@ -23,6 +27,9 @@
 #include "apic.h"
 #endif
 
+PRIVATE int osfxsr_feature; /* FXSAVE/FXRSTOR instructions support (SSEx) */
+
+
 /* set MP and NE flags to handle FPU exceptions in native mode. */
 #define CR0_MP_NE	0x0022
 /* set CR4.OSFXSR[bit 9] if FXSR is supported. */
@@ -194,6 +201,59 @@ PRIVATE void fpu_init(void)
         }
 }
 
+PUBLIC void save_fpu(struct proc *pr)
+{
+	if(!fpu_presence)
+		return;
+
+	/* If the process hasn't touched the FPU, there is nothing to do. */
+
+	if(!(pr->p_misc_flags & MF_USED_FPU))
+		return;
+
+	/* Save changed FPU context. */
+
+	if(osfxsr_feature) {
+		fxsave(pr->p_fpu_state.fpu_save_area_p);
+		fninit();
+	} else {
+		fnsave(pr->p_fpu_state.fpu_save_area_p);
+	}
+
+	/* Clear MF_USED_FPU to signal there is no unsaved FPU state. */
+
+	pr->p_misc_flags &= ~MF_USED_FPU;
+}
+
+PUBLIC void restore_fpu(struct proc *pr)
+{
+	/* If the process hasn't touched the FPU, enable the FPU exception
+	 * and don't restore anything.
+	 */
+	if(!(pr->p_misc_flags & MF_USED_FPU)) {
+		write_cr0(read_cr0() | I386_CR0_TS);
+		return;
+	}
+
+	/* If the process has touched the FPU, disable the FPU
+	 * exception (both for the kernel and for the process once
+	 * it's scheduled), and initialize or restore the FPU state.
+	 */
+
+	clts();
+
+	if(!(pr->p_misc_flags & MF_FPU_INITIALIZED)) {
+		fninit();
+		pr->p_misc_flags |= MF_FPU_INITIALIZED;
+	} else {
+		if(osfxsr_feature) {
+			fxrstor(pr->p_fpu_state.fpu_save_area_p);
+		} else {
+			frstor(pr->p_fpu_state.fpu_save_area_p);
+		}
+	}
+}
+
 PUBLIC void arch_init(void)
 {
 #ifdef CONFIG_APIC
@@ -438,3 +498,36 @@ PUBLIC struct proc * arch_finish_switch_to_user(void)
 	*((reg_t *)stk) = (reg_t) proc_ptr;
 	return proc_ptr;
 }
+
+PUBLIC void fpu_sigcontext(struct proc *pr, struct sigframe *fr, struct sigcontext *sc)
+{
+	int fp_error;
+
+	if (osfxsr_feature) {
+		fp_error = sc->sc_fpu_state.xfp_regs.fp_status &
+			~sc->sc_fpu_state.xfp_regs.fp_control;
+	} else {
+		fp_error = sc->sc_fpu_state.fpu_regs.fp_status &
+			~sc->sc_fpu_state.fpu_regs.fp_control;
+	}
+
+	if (fp_error & 0x001) {      /* Invalid op */
+		/*
+		 * swd & 0x240 == 0x040: Stack Underflow
+		 * swd & 0x240 == 0x240: Stack Overflow
+		 * User must clear the SF bit (0x40) if set
+		 */
+		fr->sf_code = FPE_FLTINV;
+	} else if (fp_error & 0x004) {
+		fr->sf_code = FPE_FLTDIV; /* Divide by Zero */
+	} else if (fp_error & 0x008) {
+		fr->sf_code = FPE_FLTOVF; /* Overflow */
+	} else if (fp_error & 0x012) {
+		fr->sf_code = FPE_FLTUND; /* Denormal, Underflow */
+	} else if (fp_error & 0x020) {
+		fr->sf_code = FPE_FLTRES; /* Precision */
+	} else {
+		fr->sf_code = 0;  /* XXX - probably should be used for FPE_INTOVF or
+				  * FPE_INTDIV */
+	}
+}

kernel/arch/i386/klib.S

@@ -50,6 +50,11 @@
 .globl	_fninit			/* non-waiting FPU initialization */
 .globl	_fnstsw			/* store status word (non-waiting) */
 .globl	_fnstcw			/* store control word (non-waiting) */
+.globl	_fxsave	
+.globl	_fnsave	
+.globl	_fxrstor	
+.globl	_frstor	
+.globl	_clts	
 
 /*
  * The routines only guarantee to preserve the registers the C compiler 
@@ -655,6 +660,10 @@ _fninit:
 	fninit
 	ret
 
+_clts:
+	clts
+	ret
+
 _fnstsw:
 	xor     %eax, %eax
 
@@ -671,6 +680,40 @@ _fnstcw:
 	pop     %eax
 	ret
 
+/*===========================================================================*/
+/*			      fxsave			     		*/
+/*===========================================================================*/
+_fxsave:
+	mov	4(%esp), %eax
+	fxsave	(%eax)		/* Do not change the operand! (gas2ack) */
+	ret
+
+/*===========================================================================*/
+/*			      fnsave			     		*/
+/*===========================================================================*/
+_fnsave:
+	mov	4(%esp), %eax
+	fnsave	(%eax)		/* Do not change the operand! (gas2ack) */
+	fwait	/* required for compatibility with processors prior pentium */
+	ret
+
+/*===========================================================================*/
+/*			      fxrstor			     		*/
+/*===========================================================================*/
+_fxrstor:
+	mov	4(%esp), %eax
+	fxrstor	(%eax)		/* Do not change the operand! (gas2ack) */
+	ret
+
+/*===========================================================================*/
+/*			      frstor			     		*/
+/*===========================================================================*/
+_frstor:
+	mov	4(%esp), %eax
+	frstor	(%eax)		/* Do not change the operand! (gas2ack) */
+	ret
+
+
 /*===========================================================================*/
 /*			      read_cr0					     */
 /*===========================================================================*/
@@ -847,3 +890,4 @@ _switch_address_space:
 	mov	%edx, _ptproc
 0:
 	ret
+

kernel/arch/i386/mpx.S

@@ -90,7 +90,7 @@ begbss:
 .globl	_params_offset
 .globl	_mon_ds
 .globl	_switch_to_user
-.globl	_lazy_fpu
+.globl	_save_fpu
 
 .globl	_hwint00	/* handlers for hardware interrupts */
 .globl	_hwint01
@@ -589,33 +589,16 @@ _inval_opcode:
 
 _copr_not_available:
 	TEST_INT_IN_KERNEL(4, copr_not_available_in_kernel)
-	clts
+	cld			/* set direction flag to a known value */
-	cld				/* set direction flag to a known value */
 	SAVE_PROCESS_CTX_NON_LAZY(0)
 	/* stop user process cycles */
 	push	%ebp
+	mov	$0, %ebp
 	call	_context_stop
 	pop	%ebp
 	lea	P_MISC_FLAGS(%ebp), %ebx
-	movw	(%ebx), %cx
+	orw	$MF_USED_FPU, (%ebx)
-	and	$MF_FPU_INITIALIZED, %cx
+	mov	$0, %ebp
-	jnz	0f			/* jump if FPU is already initialized */
-	orw	$MF_FPU_INITIALIZED, (%ebx)
-	fninit
-	jmp	copr_return
-0:					/* load FPU context for current process */
-	mov	%ss:FP_SAVE_AREA_P(%ebp), %eax
-	cmp	$0, _osfxsr_feature
-	jz	fp_l_no_fxsr		/* FXSR is not avaible. */
-
-	/* DO NOT CHANGE THE OPERAND!!! gas2ack does not handle it yet */
-	fxrstor	(%eax)
-	jmp	copr_return
-fp_l_no_fxsr:
-	/* DO NOT CHANGE THE OPERAND!!! gas2ack does not handle it yet */
-	frstor	(%eax)
-copr_return:
-	orw	$MF_USED_FPU, (%ebx)	/* fpu was used during last execution */
 	jmp	_switch_to_user
 
 copr_not_available_in_kernel:
@@ -656,51 +639,6 @@ _machine_check:
 _simd_exception:
 	EXCEPTION_NO_ERR_CODE(SIMD_EXCEPTION_VECTOR)
 
-/*===========================================================================*/
-/*                              lazy_fpu                                     */
-/*===========================================================================*/
-/* void lazy_fpu(struct proc *pptr)
- * It's called, when we are on kernel stack.
- * Actualy lazy code is just few lines, which check MF_USED_FPU,
- * another part is save_init_fpu().
- */
-_lazy_fpu:
-	push	%ebp
-	mov	%esp, %ebp
-	push	%eax
-	push	%ebx
-	push	%ecx
-	cmp	$0, _fpu_presence		/* Do we have FPU? */
-	jz	no_fpu_available
-	mov	8(%ebp), %eax			/* Get pptr */
-	lea	P_MISC_FLAGS(%eax), %ebx
-	movw	(%ebx), %cx
-	and	$MF_USED_FPU, %cx
-	jz	0f				/* Don't save FPU */
-	mov	%ss:FP_SAVE_AREA_P(%eax), %eax
-	cmp	$0, _osfxsr_feature
-	jz	fp_s_no_fxsr			/* FXSR is not avaible. */
-	
-	/* DO NOT CHANGE THE OPERAND!!! gas2ack does not handle it yet */
-	fxsave	(%eax)
-	fninit
-	jmp	fp_saved
-fp_s_no_fxsr:
-	/* DO NOT CHANGE THE OPERAND!!! gas2ack does not handle it yet */
-	fnsave	(%eax)
-	fwait	/* required for compatibility with processors prior pentium */
-fp_saved:
-	andw	$~MF_USED_FPU, (%ebx)
-0:	mov	%cr0, %eax
-	or	$0x00000008, %eax		/* Set TS flag */
-	mov	%eax, %cr0
-no_fpu_available:
-	pop	%ecx
-	pop	%ebx
-	pop	%eax
-	pop	%ebp
-	ret
-
 /*===========================================================================*/
 /*				reload_cr3				     */
 /*===========================================================================*/

kernel/arch/i386/proto.h

@@ -86,6 +86,11 @@ _PROTOTYPE( void reload_ds, (void)					);
 _PROTOTYPE( void ia32_msr_read, (u32_t reg, u32_t * hi, u32_t * lo)	);
 _PROTOTYPE( void ia32_msr_write, (u32_t reg, u32_t hi, u32_t lo)	);
 _PROTOTYPE( void fninit, (void));
+_PROTOTYPE( void clts, (void));
+_PROTOTYPE( void fxsave, (void *));
+_PROTOTYPE( void fnsave, (void *));
+_PROTOTYPE( void fxrstor, (void *));
+_PROTOTYPE( void frstor, (void *));
 _PROTOTYPE( unsigned short fnstsw, (void));
 _PROTOTYPE( void fnstcw, (unsigned short* cw));
 

kernel/arch/i386/sconst.h

@@ -140,10 +140,18 @@
 	SAVE_TRAP_CTX(displ, %ebp, %esi)		;
 
 #define SAVE_PROCESS_CTX(displ)				\
-	SAVE_PROCESS_CTX_NON_LAZY(displ)			;\
+	SAVE_PROCESS_CTX_NON_LAZY(displ)		;\
+	push	%eax					;\
+	push	%ebx					;\
+	push	%ecx					;\
+	push	%edx					;\
 	push	%ebp					;\
-	call	_lazy_fpu				;\
+	call	_save_fpu				;\
-	add	$4, %esp					;
+	pop	%ebp					;\
+	pop	%edx					;\
+	pop	%ecx					;\
+	pop	%ebx					;\
+	pop	%eax					;
 
 /*
  * clear the IF flag in eflags which are stored somewhere in memory, e.g. on

kernel/glo.h

@@ -45,7 +45,6 @@ EXTERN time_t boottime;
 EXTERN char params_buffer[512];		/* boot monitor parameters */
 EXTERN int minix_panicing;
 EXTERN char fpu_presence;
-EXTERN char osfxsr_feature;             /* FXSAVE/FXRSTOR instructions support (SSEx) */
 EXTERN int verboseboot;			/* verbose boot, init'ed in cstart */
 #define MAGICTEST 0xC0FFEE23
 EXTERN u32_t magictest;			/* global magic number */

kernel/proc.c

@@ -241,6 +241,7 @@ check_misc_flags:
 	 * restore_user_context() carries out the actual mode switch from kernel
 	 * to userspace. This function does not return
 	 */
+	restore_fpu(proc_ptr);
 	restore_user_context(proc_ptr);
 	NOT_REACHABLE;
 }

kernel/proc.h

@@ -146,6 +146,7 @@ struct proc {
 #define proc_is_preempted(p)	((p)->p_rts_flags & RTS_PREEMPTED)
 #define proc_no_quantum(p)	((p)->p_rts_flags & RTS_NO_QUANTUM)
 #define proc_ptr_ok(p)		((p)->p_magic == PMAGIC)
+#define proc_used_fpu(p)	((p)->p_misc_flags & (MF_FPU_INITIALIZED|MF_USED_FPU))
 
 /* test whether the process is scheduled by the kernel's default policy  */
 #define proc_kernel_scheduler(p)	((p)->p_scheduler == NULL || \

kernel/proto.h

@@ -5,6 +5,7 @@
 
 #include <minix/safecopies.h>
 #include <machine/archtypes.h>
+#include <sys/sigcontext.h>
 #include <a.out.h>
 
 /* Struct declarations. */
@@ -28,6 +29,9 @@ _PROTOTYPE( void cycles_accounting_init, (void)				);
 _PROTOTYPE( void context_stop, (struct proc * p)			);
 /* this is a wrapper to make calling it from assembly easier */
 _PROTOTYPE( void context_stop_idle, (void)				);
+_PROTOTYPE( void restore_fpu, (struct proc *)				);
+_PROTOTYPE( void save_fpu, (struct proc *)				);
+_PROTOTYPE( void fpu_sigcontext, (struct proc *, struct sigframe *fr, struct sigcontext *sc)	);
 
 /* main.c */
 _PROTOTYPE( void main, (void)						);

kernel/system/do_sigsend.c

@@ -27,9 +27,6 @@ PUBLIC int do_sigsend(struct proc * caller, message * m_ptr)
   struct sigcontext sc, *scp;
   struct sigframe fr, *frp;
   int proc_nr, r;
-  #if (_MINIX_CHIP == _CHIP_INTEL)
-    unsigned short int fp_error;
-  #endif
 
   if (!isokendpt(m_ptr->SIG_ENDPT, &proc_nr)) return(EINVAL);
   if (iskerneln(proc_nr)) return(EPERM);
@@ -69,38 +66,7 @@ PUBLIC int do_sigsend(struct proc * caller, message * m_ptr)
   rp->p_reg.fp = (reg_t) &frp->sf_fp;
   fr.sf_scp = scp;
 
-  #if (_MINIX_CHIP == _CHIP_INTEL)
+  fpu_sigcontext(rp, &fr, &sc);
-    if (osfxsr_feature == 1) {
-	fp_error = sc.sc_fpu_state.xfp_regs.fp_status &
-			~sc.sc_fpu_state.xfp_regs.fp_control;
-    } else {
-        fp_error = sc.sc_fpu_state.fpu_regs.fp_status &
-			~sc.sc_fpu_state.fpu_regs.fp_control;
-    }
-
-    if (fp_error & 0x001) {      /* Invalid op */
-      /*
-       * swd & 0x240 == 0x040: Stack Underflow
-       * swd & 0x240 == 0x240: Stack Overflow
-       * User must clear the SF bit (0x40) if set
-       */
-	fr.sf_code = FPE_FLTINV;
-    } else if (fp_error & 0x004) {
-	fr.sf_code = FPE_FLTDIV; /* Divide by Zero */
-    } else if (fp_error & 0x008) {
-        fr.sf_code = FPE_FLTOVF; /* Overflow */
-    } else if (fp_error & 0x012) {
-        fr.sf_code = FPE_FLTUND; /* Denormal, Underflow */
-    } else if (fp_error & 0x020) {
-        fr.sf_code = FPE_FLTRES; /* Precision */
-    } else {
-        fr.sf_code = 0;  /* XXX - probably should be used for FPE_INTOVF or
-			  * FPE_INTDIV */
-    }
-
-#else
-  fr.sf_code = 0;
-#endif
 
   fr.sf_signo = smsg.sm_signo;
   fr.sf_retadr = (void (*)()) smsg.sm_sigreturn;