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-rw-r--r--arch/parisc/math-emu/driver.c128
1 files changed, 128 insertions, 0 deletions
diff --git a/arch/parisc/math-emu/driver.c b/arch/parisc/math-emu/driver.c
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+++ b/arch/parisc/math-emu/driver.c
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+/*
+ * Linux/PA-RISC Project (http://www.parisc-linux.org/)
+ *
+ * Floating-point emulation code
+ * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that 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
+ */
+/*
+ * linux/arch/math-emu/driver.c.c
+ *
+ * decodes and dispatches unimplemented FPU instructions
+ *
+ * Copyright (C) 1999, 2000 Philipp Rumpf <prumpf@tux.org>
+ * Copyright (C) 2001 Hewlett-Packard <bame@debian.org>
+ */
+
+#include <linux/sched.h>
+#include "float.h"
+#include "math-emu.h"
+
+
+#define fptpos 31
+#define fpr1pos 10
+#define extru(r,pos,len) (((r) >> (31-(pos))) & (( 1 << (len)) - 1))
+
+#define FPUDEBUG 0
+
+/* Format of the floating-point exception registers. */
+struct exc_reg {
+ unsigned int exception : 6;
+ unsigned int ei : 26;
+};
+
+/* Macros for grabbing bits of the instruction format from the 'ei'
+ field above. */
+/* Major opcode 0c and 0e */
+#define FP0CE_UID(i) (((i) >> 6) & 3)
+#define FP0CE_CLASS(i) (((i) >> 9) & 3)
+#define FP0CE_SUBOP(i) (((i) >> 13) & 7)
+#define FP0CE_SUBOP1(i) (((i) >> 15) & 7) /* Class 1 subopcode */
+#define FP0C_FORMAT(i) (((i) >> 11) & 3)
+#define FP0E_FORMAT(i) (((i) >> 11) & 1)
+
+/* Major opcode 0c, uid 2 (performance monitoring) */
+#define FPPM_SUBOP(i) (((i) >> 9) & 0x1f)
+
+/* Major opcode 2e (fused operations). */
+#define FP2E_SUBOP(i) (((i) >> 5) & 1)
+#define FP2E_FORMAT(i) (((i) >> 11) & 1)
+
+/* Major opcode 26 (FMPYSUB) */
+/* Major opcode 06 (FMPYADD) */
+#define FPx6_FORMAT(i) ((i) & 0x1f)
+
+/* Flags and enable bits of the status word. */
+#define FPSW_FLAGS(w) ((w) >> 27)
+#define FPSW_ENABLE(w) ((w) & 0x1f)
+#define FPSW_V (1<<4)
+#define FPSW_Z (1<<3)
+#define FPSW_O (1<<2)
+#define FPSW_U (1<<1)
+#define FPSW_I (1<<0)
+
+/* Handle a floating point exception. Return zero if the faulting
+ instruction can be completed successfully. */
+int
+handle_fpe(struct pt_regs *regs)
+{
+ extern void printbinary(unsigned long x, int nbits);
+ struct siginfo si;
+ unsigned int orig_sw, sw;
+ int signalcode;
+ /* need an intermediate copy of float regs because FPU emulation
+ * code expects an artificial last entry which contains zero
+ *
+ * also, the passed in fr registers contain one word that defines
+ * the fpu type. the fpu type information is constructed
+ * inside the emulation code
+ */
+ __u64 frcopy[36];
+
+ memcpy(frcopy, regs->fr, sizeof regs->fr);
+ frcopy[32] = 0;
+
+ memcpy(&orig_sw, frcopy, sizeof(orig_sw));
+
+ if (FPUDEBUG) {
+ printk(KERN_DEBUG "FP VZOUICxxxxCQCQCQCQCQCRMxxTDVZOUI ->\n ");
+ printbinary(orig_sw, 32);
+ printk(KERN_DEBUG "\n");
+ }
+
+ signalcode = decode_fpu(frcopy, 0x666);
+
+ /* Status word = FR0L. */
+ memcpy(&sw, frcopy, sizeof(sw));
+ if (FPUDEBUG) {
+ printk(KERN_DEBUG "VZOUICxxxxCQCQCQCQCQCRMxxTDVZOUI decode_fpu returns %d|0x%x\n",
+ signalcode >> 24, signalcode & 0xffffff);
+ printbinary(sw, 32);
+ printk(KERN_DEBUG "\n");
+ }
+
+ memcpy(regs->fr, frcopy, sizeof regs->fr);
+ if (signalcode != 0) {
+ si.si_signo = signalcode >> 24;
+ si.si_errno = 0;
+ si.si_code = signalcode & 0xffffff;
+ si.si_addr = (void __user *) regs->iaoq[0];
+ force_sig_info(si.si_signo, &si, current);
+ return -1;
+ }
+
+ return signalcode ? -1 : 0;
+}