aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/nwfpe/fpmodule.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/nwfpe/fpmodule.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/arm/nwfpe/fpmodule.c')
-rw-r--r--arch/arm/nwfpe/fpmodule.c173
1 files changed, 173 insertions, 0 deletions
diff --git a/arch/arm/nwfpe/fpmodule.c b/arch/arm/nwfpe/fpmodule.c
new file mode 100644
index 000000000000..a806fea5c3ed
--- /dev/null
+++ b/arch/arm/nwfpe/fpmodule.c
@@ -0,0 +1,173 @@
1
2/*
3 NetWinder Floating Point Emulator
4 (c) Rebel.com, 1998-1999
5 (c) Philip Blundell, 1998-1999
6
7 Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
8
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.
13
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.
18
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.
22*/
23
24#include "fpa11.h"
25
26#include <linux/module.h>
27#include <linux/version.h>
28#include <linux/config.h>
29
30/* XXX */
31#include <linux/errno.h>
32#include <linux/types.h>
33#include <linux/kernel.h>
34#include <linux/signal.h>
35#include <linux/sched.h>
36#include <linux/init.h>
37/* XXX */
38
39#include "softfloat.h"
40#include "fpopcode.h"
41#include "fpmodule.h"
42#include "fpa11.inl"
43
44/* kernel symbols required for signal handling */
45#ifdef CONFIG_FPE_NWFPE_XP
46#define NWFPE_BITS "extended"
47#else
48#define NWFPE_BITS "double"
49#endif
50
51#ifdef MODULE
52void fp_send_sig(unsigned long sig, struct task_struct *p, int priv);
53#else
54#define fp_send_sig send_sig
55#define kern_fp_enter fp_enter
56
57extern char fpe_type[];
58#endif
59
60/* kernel function prototypes required */
61void fp_setup(void);
62
63/* external declarations for saved kernel symbols */
64extern void (*kern_fp_enter)(void);
65extern void (*fp_init)(union fp_state *);
66
67/* Original value of fp_enter from kernel before patched by fpe_init. */
68static void (*orig_fp_enter)(void);
69static void (*orig_fp_init)(union fp_state *);
70
71/* forward declarations */
72extern void nwfpe_enter(void);
73
74static int __init fpe_init(void)
75{
76 if (sizeof(FPA11) > sizeof(union fp_state)) {
77 printk(KERN_ERR "nwfpe: bad structure size\n");
78 return -EINVAL;
79 }
80
81 if (sizeof(FPREG) != 12) {
82 printk(KERN_ERR "nwfpe: bad register size\n");
83 return -EINVAL;
84 }
85 if (fpe_type[0] && strcmp(fpe_type, "nwfpe"))
86 return 0;
87
88 /* Display title, version and copyright information. */
89 printk(KERN_WARNING "NetWinder Floating Point Emulator V0.97 ("
90 NWFPE_BITS " precision)\n");
91
92 /* Save pointer to the old FP handler and then patch ourselves in */
93 orig_fp_enter = kern_fp_enter;
94 orig_fp_init = fp_init;
95 kern_fp_enter = nwfpe_enter;
96 fp_init = nwfpe_init_fpa;
97
98 return 0;
99}
100
101static void __exit fpe_exit(void)
102{
103 /* Restore the values we saved earlier. */
104 kern_fp_enter = orig_fp_enter;
105 fp_init = orig_fp_init;
106}
107
108/*
109ScottB: November 4, 1998
110
111Moved this function out of softfloat-specialize into fpmodule.c.
112This effectively isolates all the changes required for integrating with the
113Linux kernel into fpmodule.c. Porting to NetBSD should only require modifying
114fpmodule.c to integrate with the NetBSD kernel (I hope!).
115
116[1/1/99: Not quite true any more unfortunately. There is Linux-specific
117code to access data in user space in some other source files at the
118moment (grep for get_user / put_user calls). --philb]
119
120float_exception_flags is a global variable in SoftFloat.
121
122This function is called by the SoftFloat routines to raise a floating
123point exception. We check the trap enable byte in the FPSR, and raise
124a SIGFPE exception if necessary. If not the relevant bits in the
125cumulative exceptions flag byte are set and we return.
126*/
127
128void float_raise(signed char flags)
129{
130 register unsigned int fpsr, cumulativeTraps;
131
132#ifdef CONFIG_DEBUG_USER
133 printk(KERN_DEBUG
134 "NWFPE: %s[%d] takes exception %08x at %p from %08lx\n",
135 current->comm, current->pid, flags,
136 __builtin_return_address(0), GET_USERREG()[15]);
137#endif
138
139 /* Keep SoftFloat exception flags up to date. */
140 float_exception_flags |= flags;
141
142 /* Read fpsr and initialize the cumulativeTraps. */
143 fpsr = readFPSR();
144 cumulativeTraps = 0;
145
146 /* For each type of exception, the cumulative trap exception bit is only
147 set if the corresponding trap enable bit is not set. */
148 if ((!(fpsr & BIT_IXE)) && (flags & BIT_IXC))
149 cumulativeTraps |= BIT_IXC;
150 if ((!(fpsr & BIT_UFE)) && (flags & BIT_UFC))
151 cumulativeTraps |= BIT_UFC;
152 if ((!(fpsr & BIT_OFE)) && (flags & BIT_OFC))
153 cumulativeTraps |= BIT_OFC;
154 if ((!(fpsr & BIT_DZE)) && (flags & BIT_DZC))
155 cumulativeTraps |= BIT_DZC;
156 if ((!(fpsr & BIT_IOE)) && (flags & BIT_IOC))
157 cumulativeTraps |= BIT_IOC;
158
159 /* Set the cumulative exceptions flags. */
160 if (cumulativeTraps)
161 writeFPSR(fpsr | cumulativeTraps);
162
163 /* Raise an exception if necessary. */
164 if (fpsr & (flags << 16))
165 fp_send_sig(SIGFPE, current, 1);
166}
167
168module_init(fpe_init);
169module_exit(fpe_exit);
170
171MODULE_AUTHOR("Scott Bambrough <scottb@rebel.com>");
172MODULE_DESCRIPTION("NWFPE floating point emulator (" NWFPE_BITS " precision)");
173MODULE_LICENSE("GPL");