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-rw-r--r--arch/arm26/nwfpe/fpmodule.c182
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diff --git a/arch/arm26/nwfpe/fpmodule.c b/arch/arm26/nwfpe/fpmodule.c
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+++ b/arch/arm26/nwfpe/fpmodule.c
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+
+/*
+ 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/version.h>
+#include <linux/config.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>
+/* XXX */
+
+#include "softfloat.h"
+#include "fpopcode.h"
+#include "fpmodule.h"
+#include "fpa11.inl"
+
+/* kernel symbols required for signal handling */
+typedef struct task_struct* PTASK;
+
+#ifdef MODULE
+void fp_send_sig(unsigned long sig, PTASK p, int priv);
+#if LINUX_VERSION_CODE > 0x20115
+MODULE_AUTHOR("Scott Bambrough <scottb@rebel.com>");
+MODULE_DESCRIPTION("NWFPE floating point emulator");
+#endif
+
+#else
+#define fp_send_sig send_sig
+#define kern_fp_enter fp_enter
+
+extern char fpe_type[];
+#endif
+
+/* 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);
+
+#ifdef MODULE
+/*
+ * Return 0 if we can be unloaded. This can only happen if
+ * kern_fp_enter is still pointing at nwfpe_enter
+ */
+static int fpe_unload(void)
+{
+ return (kern_fp_enter == nwfpe_enter) ? 0 : 1;
+}
+#endif
+
+static int __init fpe_init(void)
+{
+ if (sizeof(FPA11) > sizeof(union fp_state)) {
+ printk(KERN_ERR "nwfpe: bad structure size\n");
+ return -EINVAL;
+ }
+
+ if (sizeof(FPREG) != 12) {
+ printk(KERN_ERR "nwfpe: bad register size\n");
+ return -EINVAL;
+ }
+
+#ifdef MODULE
+ if (!mod_member_present(&__this_module, can_unload))
+ return -EINVAL;
+ __this_module.can_unload = fpe_unload;
+#else
+ if (fpe_type[0] && strcmp(fpe_type, "nwfpe"))
+ return 0;
+#endif
+
+ /* Display title, version and copyright information. */
+ printk(KERN_WARNING "NetWinder Floating Point Emulator V0.95 "
+ "(c) 1998-1999 Rebel.com\n");
+
+ /* 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)
+{
+ /* 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]
+
+float_exception_flags is a global variable in SoftFloat.
+
+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.
+*/
+
+void float_raise(signed char flags)
+{
+ register unsigned int fpsr, cumulativeTraps;
+
+#ifdef CONFIG_DEBUG_USER
+ printk(KERN_DEBUG "NWFPE: %s[%d] takes exception %08x at %p from %08x\n",
+ current->comm, current->pid, flags,
+ __builtin_return_address(0), GET_USERREG()[15]);
+#endif
+
+ /* Keep SoftFloat exception flags up to date. */
+ float_exception_flags |= flags;
+
+ /* 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);