Finish pulling in the NetBSD setjmp/longjmp updates on ARM.

Store/restore the VFP registers in setjmp/longjmp on ARM EABI if VFP is
enabled in the kernel. It checks the hw.floatingpoint sysctl to see if
floating-point is available and uses this to determine if it should store
them. If it does it uses a different magic value so longjmp is able to know
if it should load them.

4 files changed, 162 insertions, 4 deletions

diff --git a/lib/libc/arm/gen/Makefile.inc b/lib/libc/arm/gen/Makefile.inc
index ec36d45..cfc8a46 100644
--- a/lib/libc/arm/gen/Makefile.inc
+++ b/lib/libc/arm/gen/Makefile.inc
@@ -3,7 +3,8 @@
 
 SRCS+=	_ctx_start.S _setjmp.S _set_tp.c alloca.S fabs.c \
 	getcontextx.c infinity.c ldexp.c makecontext.c \
-	__aeabi_read_tp.S setjmp.S signalcontext.c sigsetjmp.S flt_rounds.c
+	__aeabi_read_tp.S setjmp.S signalcontext.c sigsetjmp.S flt_rounds.c \
+	arm_initfini.c
 
 .if ${MK_ARM_EABI} == "no"
 SRCS+=	divsi3.S
diff --git a/lib/libc/arm/gen/_setjmp.S b/lib/libc/arm/gen/_setjmp.S
index ea2f427..b475f1e 100644
--- a/lib/libc/arm/gen/_setjmp.S
+++ b/lib/libc/arm/gen/_setjmp.S
@@ -36,7 +36,7 @@
 #error FPA is not supported anymore
 #endif
 
-#ifdef __ARM_EABI__
+#if defined(__ARM_EABI__) && !defined(_STANDALONE)
 	.fpu	vfp
 #endif
 
@@ -61,6 +61,26 @@ __FBSDID("$FreeBSD$");
 ENTRY(_setjmp)
 	ldr	r1, .L_setjmp_magic
 
+#if defined(__ARM_EABI__) && !defined(_STANDALONE)
+	ldr	r2, .Lfpu_present
+#ifdef PIC
+	GOT_INIT(r3, .L_setjmp_got, .L_setjmp_gotinit)
+	ldr	r2, [r2, r3]
+#else
+	ldr	r2, [r2]
+#endif
+	teq	r2, #0		/* do we have a FPU? */
+	beq	1f		/*   no, don't save VFP registers */
+
+	orr	r1, r1, #(_JB_MAGIC__SETJMP ^ _JB_MAGIC__SETJMP_VFP)
+				/* change magic to VFP magic */
+	add	r2, r0, #(_JB_REG_D8 * 4)
+	vstmia	r2, {d8-d15}
+	vmrs	r2, fpscr
+	str	r2, [r0, #(_JB_REG_FPSCR * 4)]
+1:
+#endif /* __ARM_EABI__ */
+
 	str	r1, [r0]
 
 	add	r0, r0, #(_JB_REG_R4 * 4)
@@ -72,14 +92,31 @@ ENTRY(_setjmp)
 
 .L_setjmp_magic:
 	.word	_JB_MAGIC__SETJMP
+#if defined(__ARM_EABI__) && !defined(_STANDALONE)
+	GOT_INITSYM(.L_setjmp_got, .L_setjmp_gotinit)
+.Lfpu_present:
+	.word	PIC_SYM(_libc_arm_fpu_present, GOTOFF)
+#endif /* __ARM_EABI__ */
 
 WEAK_ALIAS(___longjmp, _longjmp)
 ENTRY(_longjmp)
 	ldr	r2, [r0]			/* get magic from jmp_buf */
+	bic	r3, r2, #(_JB_MAGIC__SETJMP ^ _JB_MAGIC__SETJMP_VFP)
+						/* ignore VFP-ness of magic */
 	ldr	ip, .L_setjmp_magic		/* load magic */
-	teq	ip, r2				/* magic correct? */
+	teq	ip, r3				/* magic correct? */
 	bne	botch				/*   no, botch */
 
+#if defined(__ARM_EABI__) && !defined(_STANDALONE)
+	teq	r3, r2				/* did magic change? */
+	beq	1f				/*   no, don't restore VFP */
+	add	ip, r0, #(_JB_REG_D8 * 4)
+	vldmia	ip, {d8-d15}
+	ldr	ip, [r0, #(_JB_REG_FPSCR * 4)]
+	vmsr	fpscr, ip
+1:
+#endif /* __ARM_EABI__ */
+
 	add	r0, r0, #(_JB_REG_R4 * 4)
        	/* Restore integer registers */
         ldmia	r0, {r4-r14}
diff --git a/lib/libc/arm/gen/arm_initfini.c b/lib/libc/arm/gen/arm_initfini.c
new file mode 100644
index 0000000..9def8c8
--- /dev/null
+++ b/lib/libc/arm/gen/arm_initfini.c
@@ -0,0 +1,78 @@
+/*-
+ * Copyright (c) 2013 The NetBSD Foundation, Inc.
+ * Copyright (c) 2013 Andrew Turner
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Matt Thomas of 3am Software Foundry.
+ *
+ * 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.
+ *
+ * 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.
+ * 
+ * Bases on NetBSD lib/libc/arch/arm/misc/arm_initfini.c
+ * $NetBSD: arm_initfini.c,v 1.2 2013/01/31 06:47:55 matt Exp $
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * To properly implement setjmp/longjmp for the ARM AAPCS ABI, it has to be
+ * aware of whether there is a FPU is present or not.  Regardless of whether
+ * the hard-float ABI is being used, setjmp needs to save D8-D15.  But it can
+ * only do this if those instructions won't cause an exception.
+ */
+
+#include <sys/param.h>
+#include <sys/sysctl.h>
+
+#include <stdbool.h>
+#include <stddef.h>
+
+extern int __sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
+    void *newp, size_t newlen);
+
+int _libc_arm_fpu_present;
+static bool _libc_aapcs_initialized;
+
+void	_libc_aapcs_init(void) __attribute__((__constructor__, __used__));
+
+void
+_libc_aapcs_init(void)
+{
+	int mib[2];
+	size_t len;
+
+	if (_libc_aapcs_initialized)
+		return;
+
+	mib[0] = CTL_HW;
+	mib[1] = HW_FLOATINGPT;
+
+	len = sizeof(_libc_arm_fpu_present);
+	if (__sysctl(mib, 2, &_libc_arm_fpu_present, &len, NULL, 0) == -1 ||
+	    len != sizeof(_libc_arm_fpu_present)) {
+		/* sysctl failed, assume no vfp */
+		_libc_arm_fpu_present = 0;
+	}
+
+	_libc_aapcs_initialized = true;
+}
diff --git a/lib/libc/arm/gen/setjmp.S b/lib/libc/arm/gen/setjmp.S
index 519c3ab..b7af33b 100644
--- a/lib/libc/arm/gen/setjmp.S
+++ b/lib/libc/arm/gen/setjmp.S
@@ -36,6 +36,10 @@
 #error FPA is not supported anymore
 #endif
 
+#ifdef __ARM_EABI__
+	.fpu	vfp
+#endif
+
 #include <machine/asm.h>
 #include <machine/setjmp.h>
 
@@ -61,6 +65,27 @@ ENTRY(setjmp)
 	ldmfd	sp!, {r0, r14}
 
 	ldr	r1, .Lsetjmp_magic
+
+#ifdef __ARM_EABI__
+	ldr	r2, .Lfpu_present
+#ifdef PIC
+	GOT_INIT(r3, .Lsetjmp_got, .Lsetjmp_gotinit)
+	ldr	r2, [r2, r3]
+#else
+	ldr	r2, [r2]
+#endif
+	teq	r2, #0		/* do we have a FPU? */
+	beq	1f		/*   no, don't save VFP registers */
+
+	orr	r1, r1, #(_JB_MAGIC_SETJMP ^ _JB_MAGIC_SETJMP_VFP)
+				/* change magic to VFP magic */
+	add	r2, r0, #(_JB_REG_D8 * 4)
+	vstmia	r2, {d8-d15}
+	vmrs	r2, fpscr
+	str	r2, [r0, #(_JB_REG_FPSCR * 4)]
+1:
+#endif /* __ARM_EABI__ */
+
 	str	r1, [r0]		/* store magic */
 
 	/* Store integer registers */
@@ -71,6 +96,11 @@ ENTRY(setjmp)
 
 .Lsetjmp_magic:
 	.word	_JB_MAGIC_SETJMP
+#ifdef __ARM_EABI__
+	GOT_INITSYM(.Lsetjmp_got, .Lsetjmp_gotinit)
+.Lfpu_present:
+	.word	PIC_SYM(_libc_arm_fpu_present, GOTOFF)
+#endif /* __ARM_EABI__ */
 
 
 .weak _C_LABEL(longjmp)
@@ -78,7 +108,8 @@ ENTRY(setjmp)
 ENTRY(__longjmp)
 	ldr	r2, [r0]
 	ldr	ip, .Lsetjmp_magic
-	teq	r2, ip
+	bic	r3, r2, #(_JB_MAGIC_SETJMP ^ _JB_MAGIC_SETJMP_VFP)
+	teq	r3, ip
 	bne	.Lbotch
 
 	/* Restore the signal mask. */
@@ -89,6 +120,17 @@ ENTRY(__longjmp)
 	bl	PIC_SYM(_C_LABEL(sigprocmask), PLT)
 	ldmfd	sp!, {r0-r2, r14}
 
+#ifdef __ARM_EABI__
+	tst	r2, #(_JB_MAGIC_SETJMP ^ _JB_MAGIC_SETJMP_VFP)
+						/* is this a VFP magic? */
+	beq	1f				/*   no, don't restore VFP */
+	add	ip, r0, #(_JB_REG_D8 * 4)
+	vldmia	ip, {d8-d15}
+	ldr	ip, [r0, #(_JB_REG_FPSCR * 4)]
+	vmsr	fpscr, ip
+1:
+#endif /* __ARM_EABI__ */
+
 	add	r0, r0, #(_JB_REG_R4 * 4)
 	/* Restore integer registers */
         ldmia	r0, {r4-r14}