x86: cpa self-test, WARN_ON()
[wrt350n-kernel.git] / arch / arm / nwfpe / fpmodule.c
blob4c0ab50f399a5385adcedee14a434f281a3c5cd1
2 /*
3 NetWinder Floating Point Emulator
4 (c) Rebel.com, 1998-1999
5 (c) Philip Blundell, 1998-1999
7 Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include "fpa11.h"
26 #include <linux/module.h>
28 /* XXX */
29 #include <linux/errno.h>
30 #include <linux/types.h>
31 #include <linux/kernel.h>
32 #include <linux/signal.h>
33 #include <linux/sched.h>
34 #include <linux/init.h>
36 #include <asm/thread_notify.h>
38 #include "softfloat.h"
39 #include "fpopcode.h"
40 #include "fpmodule.h"
41 #include "fpa11.inl"
43 /* kernel symbols required for signal handling */
44 #ifdef CONFIG_FPE_NWFPE_XP
45 #define NWFPE_BITS "extended"
46 #else
47 #define NWFPE_BITS "double"
48 #endif
50 #ifdef MODULE
51 void fp_send_sig(unsigned long sig, struct task_struct *p, int priv);
52 #else
53 #define fp_send_sig send_sig
54 #define kern_fp_enter fp_enter
56 extern char fpe_type[];
57 #endif
59 static int nwfpe_notify(struct notifier_block *self, unsigned long cmd, void *v)
61 struct thread_info *thread = v;
63 if (cmd == THREAD_NOTIFY_FLUSH)
64 nwfpe_init_fpa(&thread->fpstate);
66 return NOTIFY_DONE;
69 static struct notifier_block nwfpe_notifier_block = {
70 .notifier_call = nwfpe_notify,
73 /* kernel function prototypes required */
74 void fp_setup(void);
76 /* external declarations for saved kernel symbols */
77 extern void (*kern_fp_enter)(void);
79 /* Original value of fp_enter from kernel before patched by fpe_init. */
80 static void (*orig_fp_enter)(void);
82 /* forward declarations */
83 extern void nwfpe_enter(void);
85 static int __init fpe_init(void)
87 if (sizeof(FPA11) > sizeof(union fp_state)) {
88 printk(KERN_ERR "nwfpe: bad structure size\n");
89 return -EINVAL;
92 if (sizeof(FPREG) != 12) {
93 printk(KERN_ERR "nwfpe: bad register size\n");
94 return -EINVAL;
96 if (fpe_type[0] && strcmp(fpe_type, "nwfpe"))
97 return 0;
99 /* Display title, version and copyright information. */
100 printk(KERN_WARNING "NetWinder Floating Point Emulator V0.97 ("
101 NWFPE_BITS " precision)\n");
103 thread_register_notifier(&nwfpe_notifier_block);
105 /* Save pointer to the old FP handler and then patch ourselves in */
106 orig_fp_enter = kern_fp_enter;
107 kern_fp_enter = nwfpe_enter;
109 return 0;
112 static void __exit fpe_exit(void)
114 thread_unregister_notifier(&nwfpe_notifier_block);
115 /* Restore the values we saved earlier. */
116 kern_fp_enter = orig_fp_enter;
120 ScottB: November 4, 1998
122 Moved this function out of softfloat-specialize into fpmodule.c.
123 This effectively isolates all the changes required for integrating with the
124 Linux kernel into fpmodule.c. Porting to NetBSD should only require modifying
125 fpmodule.c to integrate with the NetBSD kernel (I hope!).
127 [1/1/99: Not quite true any more unfortunately. There is Linux-specific
128 code to access data in user space in some other source files at the
129 moment (grep for get_user / put_user calls). --philb]
131 This function is called by the SoftFloat routines to raise a floating
132 point exception. We check the trap enable byte in the FPSR, and raise
133 a SIGFPE exception if necessary. If not the relevant bits in the
134 cumulative exceptions flag byte are set and we return.
137 void float_raise(signed char flags)
139 register unsigned int fpsr, cumulativeTraps;
141 #ifdef CONFIG_DEBUG_USER
142 /* Ignore inexact errors as there are far too many of them to log */
143 if (flags & ~BIT_IXC)
144 printk(KERN_DEBUG
145 "NWFPE: %s[%d] takes exception %08x at %p from %08lx\n",
146 current->comm, current->pid, flags,
147 __builtin_return_address(0), GET_USERREG()->ARM_pc);
148 #endif
150 /* Read fpsr and initialize the cumulativeTraps. */
151 fpsr = readFPSR();
152 cumulativeTraps = 0;
154 /* For each type of exception, the cumulative trap exception bit is only
155 set if the corresponding trap enable bit is not set. */
156 if ((!(fpsr & BIT_IXE)) && (flags & BIT_IXC))
157 cumulativeTraps |= BIT_IXC;
158 if ((!(fpsr & BIT_UFE)) && (flags & BIT_UFC))
159 cumulativeTraps |= BIT_UFC;
160 if ((!(fpsr & BIT_OFE)) && (flags & BIT_OFC))
161 cumulativeTraps |= BIT_OFC;
162 if ((!(fpsr & BIT_DZE)) && (flags & BIT_DZC))
163 cumulativeTraps |= BIT_DZC;
164 if ((!(fpsr & BIT_IOE)) && (flags & BIT_IOC))
165 cumulativeTraps |= BIT_IOC;
167 /* Set the cumulative exceptions flags. */
168 if (cumulativeTraps)
169 writeFPSR(fpsr | cumulativeTraps);
171 /* Raise an exception if necessary. */
172 if (fpsr & (flags << 16))
173 fp_send_sig(SIGFPE, current, 1);
176 module_init(fpe_init);
177 module_exit(fpe_exit);
179 MODULE_AUTHOR("Scott Bambrough <scottb@rebel.com>");
180 MODULE_DESCRIPTION("NWFPE floating point emulator (" NWFPE_BITS " precision)");
181 MODULE_LICENSE("GPL");