IEEE 754 floating point completion code, and implementation of the

FP_C (Floating Point Control Quadword).

From ross@NetBSD.  Added a way to disable it with option NO_IEEE,
which appears on the ramdisks to save space.  This affects only
programs compiled with -mieee, and what it essentially does is
enabling infinities and NaNs, instead of generating SIGFPE on
division by zero, overflow, etc.
ok art, deraadt

6 files changed, 295 insertions, 14 deletions

diff --git a/sys/arch/alpha/include/cpu.h b/sys/arch/alpha/include/cpu.h
index b599120df2e..4a4ff665401 100644
--- a/sys/arch/alpha/include/cpu.h
+++ b/sys/arch/alpha/include/cpu.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: cpu.h,v 1.15 2001/11/06 18:41:09 art Exp $ */
+/* $OpenBSD: cpu.h,v 1.16 2002/04/28 20:55:14 pvalchev Exp $ */
 /* $NetBSD: cpu.h,v 1.45 2000/08/21 02:03:12 thorpej Exp $ */
 
 /*-
@@ -83,6 +83,22 @@
 #ifndef _ALPHA_CPU_H_
 #define _ALPHA_CPU_H_
 
+#ifndef NO_IEEE
+typedef union alpha_s_float {
+	u_int32_t i;
+	u_int32_t frac: 23,
+		exp:   8,
+		sign:  1;
+} s_float;
+
+typedef union alpha_t_float {
+	u_int64_t i;
+	u_int64_t frac: 52,
+		exp:  11,
+		sign:  1;
+} t_float;
+#endif
+
 /*
  * Exported definitions unique to Alpha cpu support.
  */
@@ -100,7 +116,11 @@ struct reg;
 struct rpb;
 struct trapframe;
 
+extern u_long cpu_implver;		/* from IMPLVER instruction */
+extern u_long cpu_amask;		/* from AMASK instruction */
 extern int bootdev_debug;
+extern int alpha_fp_sync_complete;
+extern int alpha_unaligned_print, alpha_unaligned_fix, alpha_unaligned_sigbus;
 
 void	XentArith(u_int64_t, u_int64_t, u_int64_t);		/* MAGIC */
 void	XentIF(u_int64_t, u_int64_t, u_int64_t);		/* MAGIC */
@@ -195,6 +215,11 @@ struct cpu_info {
 #define	CPUF_PRIMARY	0x01		/* CPU is primary CPU */
 #define	CPUF_PRESENT	0x02		/* CPU is present */
 #define	CPUF_RUNNING	0x04		/* CPU is running */
+#define	CPUF_PAUSED	0x08		/* CPU is paused */
+#define	CPUF_FPUSAVE	0x10		/* CPU is currently in fpusave_cpu() */
+
+void	fpusave_cpu(struct cpu_info *, int);
+void	fpusave_proc(struct proc *, int);
 
 #if defined(MULTIPROCESSOR)
 extern	__volatile u_long cpus_running;
@@ -218,9 +243,6 @@ extern	struct cpu_info cpu_info_store;
 #define	fpcurproc	curcpu()->ci_fpcurproc
 #define	curpcb		curcpu()->ci_curpcb
 
-extern	u_long cpu_implver;		/* from IMPLVER instruction */
-extern	u_long cpu_amask;		/* from AMASK instruction */
-
 /*
  * definitions of cpu-dependent requirements
  * referenced in generic code
@@ -309,8 +331,9 @@ do {									\
 #define	CPU_UNALIGNED_FIX	4	/* int: fix unaligned accesses */
 #define	CPU_UNALIGNED_SIGBUS	5	/* int: SIGBUS unaligned accesses */
 #define	CPU_BOOTED_KERNEL	6	/* string: booted kernel name */
-#define CPU_CHIPSET		7	/* chipset information */
-#define	CPU_MAXID		8	/* 6 valid machdep IDs */
+#define	CPU_FP_SYNC_COMPLETE	7	/* int: always fixup sync fp traps */
+#define	CPU_MAXID		8	/* 7 valid machdep IDs */
+#define CPU_CHIPSET		9	/* chipset information */
 
 #define CPU_CHIPSET_MEM		1	/* PCI memory address */
 #define CPU_CHIPSET_BWX		2	/* PCI supports BWX */
@@ -328,6 +351,7 @@ do {									\
 	{ "unaligned_sigbus", CTLTYPE_INT }, \
 	{ "booted_kernel", CTLTYPE_STRING }, \
 	{ "chipset", CTLTYPE_NODE }, \
+	{ "fp_sync_complete", CTLTYPE_INT }, \
 }
 
 #ifdef _KERNEL
@@ -338,5 +362,23 @@ struct reg;
 struct rpb;
 struct trapframe;
 
+/* IEEE and VAX FP completion */
+
+#ifndef NO_IEEE
+void alpha_sts(int, s_float *);					/* MAGIC */
+void alpha_stt(int, t_float *);					/* MAGIC */
+void alpha_lds(int, s_float *);					/* MAGIC */
+void alpha_ldt(int, t_float *);					/* MAGIC */
+
+uint64_t alpha_read_fpcr(void);					/* MAGIC */
+void alpha_write_fpcr(u_int64_t);				/* MAGIC */
+
+u_int64_t alpha_read_fp_c(struct proc *);
+void alpha_write_fp_c(struct proc *, u_int64_t);
+
+void alpha_enable_fp(struct proc *, int);
+int alpha_fp_complete(u_long, u_long, struct proc *, u_int64_t *);
+#endif
+
 #endif /* _KERNEL */
 #endif /* _ALPHA_CPU_H_ */
diff --git a/sys/arch/alpha/include/fpu.h b/sys/arch/alpha/include/fpu.h
new file mode 100644
index 00000000000..1aa71c1e765
--- /dev/null
+++ b/sys/arch/alpha/include/fpu.h
@@ -0,0 +1,121 @@
+/*	$OpenBSD: fpu.h,v 1.1 2002/04/28 20:55:14 pvalchev Exp $	*/
+/*	$NetBSD: fpu.h,v 1.4 2001/04/26 03:10:46 ross Exp $	*/
+
+/*-
+ * Copyright (c) 2001 Ross Harvey
+ * All rights reserved.
+ *
+ * This software was written for NetBSD.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the NetBSD
+ *	Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _ALPHA_FPU_H_
+#define _ALPHA_FPU_H_
+
+#define	_FP_C_DEF(n) (1UL << (n))
+
+/*
+ * Most of these next definitions were moved from <ieeefp.h>. Apparently the
+ * names happen to match those exported by Compaq and Linux from their fpu.h
+ * files.
+ */
+
+#define	FPCR_SUM	_FP_C_DEF(63)
+#define	FPCR_INED	_FP_C_DEF(62)
+#define	FPCR_UNFD	_FP_C_DEF(61)
+#define	FPCR_UNDZ	_FP_C_DEF(60)
+#define	FPCR_DYN(rm)	((unsigned long)(rm) << 58)
+#define	FPCR_IOV	_FP_C_DEF(57)
+#define	FPCR_INE	_FP_C_DEF(56)
+#define	FPCR_UNF	_FP_C_DEF(55)
+#define	FPCR_OVF	_FP_C_DEF(54)
+#define	FPCR_DZE	_FP_C_DEF(53)
+#define	FPCR_INV	_FP_C_DEF(52)
+#define	FPCR_OVFD	_FP_C_DEF(51)
+#define	FPCR_DZED	_FP_C_DEF(50)
+#define	FPCR_INVD	_FP_C_DEF(49)
+#define	FPCR_DNZ	_FP_C_DEF(48)
+#define	FPCR_DNOD	_FP_C_DEF(47)
+
+#define	FPCR_MIRRORED (FPCR_INE | FPCR_UNF | FPCR_OVF | FPCR_DZE | FPCR_INV)
+#define FPCR_MIR_START 52
+
+/*
+ * The AARM specifies the bit positions of the software word used for
+ * user mode interface to the control and status of the kernel completion
+ * routines. Although it largely just redefines the FPCR, it shuffles
+ * the bit order. The names of the bits are defined in the AARM, and
+ * the definition prefix can easily be determined from public domain
+ * programs written to either the Compaq or Linux interfaces, which
+ * appear to be identical.
+ */
+
+#define IEEE_STATUS_DNO _FP_C_DEF(22)
+#define IEEE_STATUS_INE _FP_C_DEF(21)
+#define IEEE_STATUS_UNF _FP_C_DEF(20)
+#define IEEE_STATUS_OVF _FP_C_DEF(19)
+#define IEEE_STATUS_DZE _FP_C_DEF(18)
+#define IEEE_STATUS_INV _FP_C_DEF(17)
+
+#define	IEEE_TRAP_ENABLE_DNO _FP_C_DEF(6)
+#define	IEEE_TRAP_ENABLE_INE _FP_C_DEF(5)
+#define	IEEE_TRAP_ENABLE_UNF _FP_C_DEF(4)
+#define	IEEE_TRAP_ENABLE_OVF _FP_C_DEF(3)
+#define	IEEE_TRAP_ENABLE_DZE _FP_C_DEF(2)
+#define	IEEE_TRAP_ENABLE_INV _FP_C_DEF(1)
+
+#define	IEEE_INHERIT _FP_C_DEF(14)
+#define	IEEE_MAP_UMZ _FP_C_DEF(13)
+#define	IEEE_MAP_DMZ _FP_C_DEF(12)
+
+#define FP_C_MIRRORED (IEEE_STATUS_INE | IEEE_STATUS_UNF | IEEE_STATUS_OVF\
+				| IEEE_STATUS_DZE | IEEE_STATUS_INV)
+#define	FP_C_MIR_START 17
+
+#ifdef _KERNEL
+
+#define	FLD_MASK(len) ((1UL << (len)) - 1)
+#define FLD_CLEAR(obj, origin, len)	\
+		((obj) & ~(FLD_MASK(len) << (origin)))
+#define	FLD_INSERT(obj, origin, len, value)	\
+		(FLD_CLEAR(obj, origin, len) | (value) << origin)
+
+#define	FP_C_TO_OPENBSD_MASK(fp_c) 	((fp_c) >> 1 & 0x3f)
+#define	FP_C_TO_OPENBSD_FLAG(fp_c) 	((fp_c) >> 17 & 0x3f)
+#define OPENBSD_MASK_TO_FP_C(m)		(((m) & 0x3f) << 1)
+#define OPENBSD_FLAG_TO_FP_C(s)		(((s) & 0x3f) << 17)
+#define	CLEAR_FP_C_MASK(fp_c)		((fp_c) & ~(0x3f << 1))
+#define	CLEAR_FP_C_FLAG(fp_c)		((fp_c) & ~(0x3f << 17))
+#define	SET_FP_C_MASK(fp_c, m) (CLEAR_FP_C_MASK(fp_c) | OPENBSD_MASK_TO_FP_C(m))
+#define	SET_FP_C_FLAG(fp_c, m) (CLEAR_FP_C_FLAG(fp_c) | OPENBSD_FLAG_TO_FP_C(m))
+
+#endif
+
+#endif
diff --git a/sys/arch/alpha/include/ieeefp.h b/sys/arch/alpha/include/ieeefp.h
index 4ebb20b0aa5..4cb8539a2c1 100644
--- a/sys/arch/alpha/include/ieeefp.h
+++ b/sys/arch/alpha/include/ieeefp.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ieeefp.h,v 1.3 1996/10/30 22:39:08 niklas Exp $	*/
+/*	$OpenBSD: ieeefp.h,v 1.4 2002/04/28 20:55:14 pvalchev Exp $	*/
 /*	$NetBSD: ieeefp.h,v 1.1 1995/04/29 01:09:17 cgd Exp $	*/
 
 /* 
@@ -10,18 +10,45 @@
 #define _ALPHA_IEEEFP_H_
 
 typedef int fp_except;
+
+#ifdef _KERNEL
+
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <machine/fpu.h>
+#include <machine/cpu.h>
+
+/* FP_X_IOV is intentionally omitted from the architecture flags mask */
+
+#define	FP_AA_FLAGS (FP_X_INV | FP_X_DZ | FP_X_OFL | FP_X_UFL | FP_X_IMP)
+
+#define float_raise(f)						\
+	do curproc->p_md.md_flags |= OPENBSD_FLAG_TO_FP_C(f);	\
+	while(0)
+
+#define	float_set_inexact()	float_raise(FP_X_IMP)
+#define	float_set_invalid()	float_raise(FP_X_INV)
+#define	fpgetround()		(alpha_read_fpcr() >> 58 & 3)
+
+#endif
+
 #define	FP_X_INV	0x01	/* invalid operation exception */
 #define	FP_X_DZ		0x02	/* divide-by-zero exception */
 #define	FP_X_OFL	0x04	/* overflow exception */
 #define	FP_X_UFL	0x08	/* underflow exception */
 #define	FP_X_IMP	0x10	/* imprecise (loss of precision; "inexact") */
-#define	FP_X_IOV	0x20    /* integer overflow XXX? */
+#define	FP_X_IOV	0x20    /* integer overflow */
 
+/*
+ * fp_rnd bits match the fpcr, below, as well as bits 12:11
+ * in fp operate instructions
+ */
 typedef enum {
-    FP_RZ=0,			/* round to zero (truncate) */
-    FP_RM=1,			/* round toward negative infinity */
-    FP_RN=2,			/* round to nearest representable number */
-    FP_RP=3			/* round toward positive infinity */
+    FP_RZ = 0,			/* round to zero (truncate) */
+    FP_RM = 1,			/* round toward negative infinity */
+    FP_RN = 2,			/* round to nearest representable number */
+    FP_RP = 3,			/* round toward positive infinity */
+    _FP_DYNAMIC=FP_RP
 } fp_rnd;
 
 #endif /* _ALPHA_IEEEFP_H_ */
diff --git a/sys/arch/alpha/include/pcb.h b/sys/arch/alpha/include/pcb.h
index f7eb89491af..b91bdf22438 100644
--- a/sys/arch/alpha/include/pcb.h
+++ b/sys/arch/alpha/include/pcb.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pcb.h,v 1.5 2002/03/14 01:26:27 millert Exp $	*/
+/*	$OpenBSD: pcb.h,v 1.6 2002/04/28 20:55:14 pvalchev Exp $	*/
 /*	$NetBSD: pcb.h,v 1.5 1996/11/13 22:21:00 cgd Exp $	*/
 
 /*
@@ -52,6 +52,7 @@ struct pcb {
 	struct fpreg	pcb_fp;			/* FP registers		[SW] */
 	unsigned long	pcb_onfault;		/* for copy faults	[SW] */
 	unsigned long	pcb_accessaddr;		/* for [fs]uswintr	[SW] */
+	struct cpu_info *__volatile pcb_fpcpu;	/* CPU with our FP state[SW] */
 };
 
 /*
diff --git a/sys/arch/alpha/include/proc.h b/sys/arch/alpha/include/proc.h
index fd698f6f9e1..dab1d4c78c0 100644
--- a/sys/arch/alpha/include/proc.h
+++ b/sys/arch/alpha/include/proc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: proc.h,v 1.7 2002/03/14 01:26:27 millert Exp $	*/
+/*	$OpenBSD: proc.h,v 1.8 2002/04/28 20:55:14 pvalchev Exp $	*/
 /*	$NetBSD: proc.h,v 1.2 1995/03/24 15:01:36 cgd Exp $	*/
 
 /*
@@ -45,7 +45,28 @@ struct mdproc {
 	struct mdbpt md_sstep[2];	/* two breakpoints for sstep */
 };
 
+/*
+ * md_flags usage
+ * --------------
+ * MDP_FPUSED
+ *      A largely unused bit indicating the presence of FPU history.
+ *      Cleared on exec. Set but not used by the fpu context switcher
+ *      itself.
+ * 
+ * MDP_FP_C
+ *      The architected FP Control word. It should forever begin at bit 1,
+ *      as the bits are AARM specified and this way it doesn't need to be
+ *      shifted.
+ * 
+ *      Until C99 there was never an IEEE 754 API, making most of the
+ *      standard useless.  Because of overlapping AARM, OSF/1, NetBSD, and
+ *      C99 API's, the use of the MDP_FP_C bits is defined variously in
+ *      ieeefp.h and fpu.h.
+ */
 #define	MDP_FPUSED	0x0001		/* Process used the FPU */
+#ifndef NO_IEEE
+#define	MDP_FP_C	0x7ffffe	/* Extended FP_C Quadword bits */
+#endif
 #define MDP_STEP1	0x0002		/* Single step normal */
 #define MDP_STEP2	0x0003		/* Single step branch */
 
diff --git a/sys/arch/alpha/include/sysarch.h b/sys/arch/alpha/include/sysarch.h
new file mode 100644
index 00000000000..a439c52c7e2
--- /dev/null
+++ b/sys/arch/alpha/include/sysarch.h
@@ -0,0 +1,69 @@
+/*	$OpenBSD: sysarch.h,v 1.3 2002/04/28 20:55:14 pvalchev Exp $	*/
+/*	$NetBSD: sysarch.h,v 1.8 2001/04/26 03:10:46 ross Exp $	*/
+
+/*-
+ * Copyright (c) 2000 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jason R. Thorpe.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the NetBSD
+ *	Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _ALPHA_SYSARCH_H_
+#define _ALPHA_SYSARCH_H_
+
+#include <machine/bus.h>
+#include <machine/ieeefp.h>
+
+/*
+ * Architecture specific syscalls (ALPHA)
+ */
+
+#define	ALPHA_FPGETMASK			0
+#define	ALPHA_FPSETMASK			1
+#define	ALPHA_FPSETSTICKY		2
+#define	ALPHA_FPGETSTICKY		6
+#define	ALPHA_GET_FP_C			7
+#define	ALPHA_SET_FP_C			8
+
+struct alpha_fp_except_args {
+	fp_except mask;
+};
+
+struct alpha_fp_c_args {
+	uint64_t fp_c;
+};
+
+#ifdef _KERNEL
+int	sysarch(int, void *);
+#endif /* _KERNEL */
+
+#endif /* !_ALPHA_SYSARCH_H_ */