1 files changed, 112 insertions, 0 deletions
diff --git a/arch/parisc/math-emu/driver.c b/arch/parisc/math-emu/driver.c
new file mode 100644
index 000000000..6ce427b58
--- /dev/null
+++ b/arch/parisc/math-emu/driver.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Linux/PA-RISC Project (http://www.parisc-linux.org/)
+ *
+ * Floating-point emulation code
+ *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
+ */
+/*
+ *  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/signal.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);
+	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) {
+	    force_sig_fault(signalcode >> 24, signalcode & 0xffffff,
+			    (void __user *) regs->iaoq[0]);
+	    return -1;
+	}
+
+	return signalcode ? -1 : 0;
+}