mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 01:51:53 +00:00
1da177e4c3
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!
174 lines
4.9 KiB
C
174 lines
4.9 KiB
C
|
|
/*
|
|
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 */
|
|
#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
|
|
|
|
/* kernel function prototypes required */
|
|
void fp_setup(void);
|
|
|
|
/* external declarations for saved kernel symbols */
|
|
extern void (*kern_fp_enter)(void);
|
|
extern void (*fp_init)(union fp_state *);
|
|
|
|
/* Original value of fp_enter from kernel before patched by fpe_init. */
|
|
static void (*orig_fp_enter)(void);
|
|
static void (*orig_fp_init)(union fp_state *);
|
|
|
|
/* forward declarations */
|
|
extern void nwfpe_enter(void);
|
|
|
|
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;
|
|
}
|
|
if (fpe_type[0] && strcmp(fpe_type, "nwfpe"))
|
|
return 0;
|
|
|
|
/* Display title, version and copyright information. */
|
|
printk(KERN_WARNING "NetWinder Floating Point Emulator V0.97 ("
|
|
NWFPE_BITS " precision)\n");
|
|
|
|
/* Save pointer to the old FP handler and then patch ourselves in */
|
|
orig_fp_enter = kern_fp_enter;
|
|
orig_fp_init = fp_init;
|
|
kern_fp_enter = nwfpe_enter;
|
|
fp_init = nwfpe_init_fpa;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit fpe_exit(void)
|
|
{
|
|
/* Restore the values we saved earlier. */
|
|
kern_fp_enter = orig_fp_enter;
|
|
fp_init = orig_fp_init;
|
|
}
|
|
|
|
/*
|
|
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 %08lx\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);
|
|
|
|
MODULE_AUTHOR("Scott Bambrough <scottb@rebel.com>");
|
|
MODULE_DESCRIPTION("NWFPE floating point emulator (" NWFPE_BITS " precision)");
|
|
MODULE_LICENSE("GPL");
|