Initial import

1 files changed, 190 insertions, 0 deletions

diff --git a/arch/arm/nwfpe/fpmodule.c b/arch/arm/nwfpe/fpmodule.c
new file mode 100644
index 000000000..ec717c190
--- /dev/null
+++ b/arch/arm/nwfpe/fpmodule.c
@@ -0,0 +1,190 @@
+
+/*
+    NetWinder Floating Point Emulator
+    (c) Rebel.com, 1998-1999
+    (c) Philip Blundell, 1998-1999
+
+    Direct questions, comments to Scott Bambrough <scottb@netwinder.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 of the License, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "fpa11.h"
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+
+/* XXX */
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+
+#include <asm/thread_notify.h>
+
+#include "softfloat.h"
+#include "fpopcode.h"
+#include "fpmodule.h"
+#include "fpa11.inl"
+
+/* kernel symbols required for signal handling */
+#ifdef CONFIG_FPE_NWFPE_XP
+#define NWFPE_BITS "extended"
+#else
+#define NWFPE_BITS "double"
+#endif
+
+#ifdef MODULE
+void fp_send_sig(unsigned long sig, struct task_struct *p, int priv);
+#else
+#define fp_send_sig	send_sig
+#define kern_fp_enter	fp_enter
+
+extern char fpe_type[];
+#endif
+
+static int nwfpe_notify(struct notifier_block *self, unsigned long cmd, void *v)
+{
+	struct thread_info *thread = v;
+
+	if (cmd == THREAD_NOTIFY_FLUSH)
+		nwfpe_init_fpa(&thread->fpstate);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block nwfpe_notifier_block = {
+	.notifier_call = nwfpe_notify,
+};
+
+/* kernel function prototypes required */
+void fp_setup(void);
+
+/* external declarations for saved kernel symbols */
+extern void (*kern_fp_enter)(void);
+
+/* Original value of fp_enter from kernel before patched by fpe_init. */
+static void (*orig_fp_enter)(void);
+
+/* forward declarations */
+extern void nwfpe_enter(void);
+
+static int __init fpe_init(void)
+{
+	if (sizeof(FPA11) > sizeof(union fp_state)) {
+		pr_err("nwfpe: bad structure size\n");
+		return -EINVAL;
+	}
+
+	if (sizeof(FPREG) != 12) {
+		pr_err("nwfpe: bad register size\n");
+		return -EINVAL;
+	}
+	if (fpe_type[0] && strcmp(fpe_type, "nwfpe"))
+		return 0;
+
+	/* Display title, version and copyright information. */
+	pr_info("NetWinder Floating Point Emulator V0.97 ("
+	        NWFPE_BITS " precision)\n");
+
+	thread_register_notifier(&nwfpe_notifier_block);
+
+	/* Save pointer to the old FP handler and then patch ourselves in */
+	orig_fp_enter = kern_fp_enter;
+	kern_fp_enter = nwfpe_enter;
+
+	return 0;
+}
+
+static void __exit fpe_exit(void)
+{
+	thread_unregister_notifier(&nwfpe_notifier_block);
+	/* Restore the values we saved earlier. */
+	kern_fp_enter = orig_fp_enter;
+}
+
+/*
+ScottB:  November 4, 1998
+
+Moved this function out of softfloat-specialize into fpmodule.c.
+This effectively isolates all the changes required for integrating with the
+Linux kernel into fpmodule.c.  Porting to NetBSD should only require modifying
+fpmodule.c to integrate with the NetBSD kernel (I hope!).
+
+[1/1/99: Not quite true any more unfortunately.  There is Linux-specific
+code to access data in user space in some other source files at the 
+moment (grep for get_user / put_user calls).  --philb]
+
+This function is called by the SoftFloat routines to raise a floating
+point exception.  We check the trap enable byte in the FPSR, and raise
+a SIGFPE exception if necessary.  If not the relevant bits in the 
+cumulative exceptions flag byte are set and we return.
+*/
+
+#ifdef CONFIG_DEBUG_USER
+/* By default, ignore inexact errors as there are far too many of them to log */
+static int debug = ~BIT_IXC;
+#endif
+
+void float_raise(signed char flags)
+{
+	register unsigned int fpsr, cumulativeTraps;
+
+#ifdef CONFIG_DEBUG_USER
+	if (flags & debug)
+ 		printk(KERN_DEBUG
+		       "NWFPE: %s[%d] takes exception %08x at %pf from %08lx\n",
+		       current->comm, current->pid, flags,
+		       __builtin_return_address(0), GET_USERREG()->ARM_pc);
+#endif
+
+	/* Read fpsr and initialize the cumulativeTraps.  */
+	fpsr = readFPSR();
+	cumulativeTraps = 0;
+
+	/* For each type of exception, the cumulative trap exception bit is only
+	   set if the corresponding trap enable bit is not set.  */
+	if ((!(fpsr & BIT_IXE)) && (flags & BIT_IXC))
+		cumulativeTraps |= BIT_IXC;
+	if ((!(fpsr & BIT_UFE)) && (flags & BIT_UFC))
+		cumulativeTraps |= BIT_UFC;
+	if ((!(fpsr & BIT_OFE)) && (flags & BIT_OFC))
+		cumulativeTraps |= BIT_OFC;
+	if ((!(fpsr & BIT_DZE)) && (flags & BIT_DZC))
+		cumulativeTraps |= BIT_DZC;
+	if ((!(fpsr & BIT_IOE)) && (flags & BIT_IOC))
+		cumulativeTraps |= BIT_IOC;
+
+	/* Set the cumulative exceptions flags.  */
+	if (cumulativeTraps)
+		writeFPSR(fpsr | cumulativeTraps);
+
+	/* Raise an exception if necessary.  */
+	if (fpsr & (flags << 16))
+		fp_send_sig(SIGFPE, current, 1);
+}
+
+module_init(fpe_init);
+module_exit(fpe_exit);
+
+MODULE_AUTHOR("Scott Bambrough <scottb@rebel.com>");
+MODULE_DESCRIPTION("NWFPE floating point emulator (" NWFPE_BITS " precision)");
+MODULE_LICENSE("GPL");
+
+#ifdef CONFIG_DEBUG_USER
+module_param(debug, int, 0644);
+#endif