Kernel FPU emulator, chain saw edition.

1 files changed, 89 insertions, 0 deletions

diff --git a/arch/mips/math-emu/kernel_linkage.c b/arch/mips/math-emu/kernel_linkage.c
new file mode 100644
index 000000000..93c84f8b0
--- /dev/null
+++ b/arch/mips/math-emu/kernel_linkage.c
@@ -0,0 +1,89 @@
+/**************************************************************************
+ *
+ *  arch/mips/math_emu/kernel_linkage.c
+ *
+ *  Kevin D. Kissell, kevink@mips and Carsten Langgaard, carstenl@mips.com
+ *  Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
+ *
+ * ########################################################################
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ *************************************************************************/
+/*
+ * Routines corresponding to Linux kernel FP context
+ * manipulation primitives for the Algorithmics MIPS
+ * FPU Emulator
+ */
+
+#include <linux/sched.h>
+#include <asm/processor.h>
+#include <asm/signal.h>
+#include <asm/uaccess.h>
+
+#include <asm/fpu_emulator.h>
+
+extern struct mips_fpu_emulator_private fpuemuprivate;
+
+#define SIGNALLING_NAN 0x7ff800007ff80000LL
+
+void fpu_emulator_init_fpu(void)
+{
+	int i;
+
+/*	printk("Algorithmics/MIPS FPU Emulator v1.4\n");*/
+	current->thread.fpu.soft.sr = 0;
+	for (i = 0; i < 32; i++) {
+		current->thread.fpu.soft.regs[i] = SIGNALLING_NAN;
+	}
+}
+
+
+/*
+ * Emulator context save/restore to/from a signal context
+ * presumed to be on the user stack, and therefore accessed
+ * with appropriate macros from uaccess.h
+ */
+
+int fpu_emulator_save_context(struct sigcontext *sc)
+{
+	int i;
+	int err = 0;
+
+	for (i = 0; i < 32; i++) {
+		err |=
+		    __put_user(current->thread.fpu.soft.regs[i],
+			       &sc->sc_fpregs[i]);
+	}
+	err |= __put_user(current->thread.fpu.soft.sr, &sc->sc_fpc_csr);
+	err |= __put_user(fpuemuprivate.eir, &sc->sc_fpc_eir);
+
+	return err;
+}
+
+int fpu_emulator_restore_context(struct sigcontext *sc)
+{
+	int i;
+	int err = 0;
+
+	for (i = 0; i < 32; i++) {
+		err |=
+		    __get_user(current->thread.fpu.soft.regs[i],
+			       &sc->sc_fpregs[i]);
+	}
+	err |= __get_user(current->thread.fpu.soft.sr, &sc->sc_fpc_csr);
+	err |= __get_user(fpuemuprivate.eir, &sc->sc_fpc_eir);
+
+	return err;
+}