xref: /linux/arch/mips/include/asm/fpu_emulator.h (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1 /*
2  *  This program is free software; you can distribute it and/or modify it
3  *  under the terms of the GNU General Public License (Version 2) as
4  *  published by the Free Software Foundation.
5  *
6  *  This program is distributed in the hope it will be useful, but WITHOUT
7  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
8  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
9  *  for more details.
10  *
11  *  You should have received a copy of the GNU General Public License along
12  *  with this program; if not, write to the Free Software Foundation, Inc.,
13  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
14  *
15  * Further private data for which no space exists in mips_fpu_struct.
16  * This should be subsumed into the mips_fpu_struct structure as
17  * defined in processor.h as soon as the absurd wired absolute assembler
18  * offsets become dynamic at compile time.
19  *
20  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
21  * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
22  */
23 #ifndef _ASM_FPU_EMULATOR_H
24 #define _ASM_FPU_EMULATOR_H
25 
26 #include <linux/sched.h>
27 #include <asm/dsemul.h>
28 #include <asm/thread_info.h>
29 #include <asm/inst.h>
30 #include <asm/local.h>
31 #include <asm/processor.h>
32 
33 #ifdef CONFIG_DEBUG_FS
34 
35 struct mips_fpu_emulator_stats {
36 	unsigned long emulated;
37 	unsigned long loads;
38 	unsigned long stores;
39 	unsigned long cp1ops;
40 	unsigned long cp1xops;
41 	unsigned long errors;
42 	unsigned long ieee754_inexact;
43 	unsigned long ieee754_underflow;
44 	unsigned long ieee754_overflow;
45 	unsigned long ieee754_zerodiv;
46 	unsigned long ieee754_invalidop;
47 	unsigned long ds_emul;
48 };
49 
50 DECLARE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats);
51 
52 #define MIPS_FPU_EMU_INC_STATS(M)					\
53 do {									\
54 	preempt_disable();						\
55 	__this_cpu_inc(fpuemustats.M);					\
56 	preempt_enable();						\
57 } while (0)
58 
59 #else
60 #define MIPS_FPU_EMU_INC_STATS(M) do { } while (0)
61 #endif /* CONFIG_DEBUG_FS */
62 
63 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
64 				    struct mips_fpu_struct *ctx, int has_fpu,
65 				    void *__user *fault_addr);
66 void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr,
67 		     struct task_struct *tsk);
68 int process_fpemu_return(int sig, void __user *fault_addr,
69 			 unsigned long fcr31);
70 int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
71 		  unsigned long *contpc);
72 int mm_isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
73 		     unsigned long *contpc);
74 
75 #define SIGNALLING_NAN 0x7ff800007ff80000LL
76 
77 static inline void fpu_emulator_init_fpu(void)
78 {
79 	struct task_struct *t = current;
80 	int i;
81 
82 	for (i = 0; i < 32; i++)
83 		set_fpr64(&t->thread.fpu.fpr[i], 0, SIGNALLING_NAN);
84 }
85 
86 /*
87  * Mask the FCSR Cause bits according to the Enable bits, observing
88  * that Unimplemented is always enabled.
89  */
90 static inline unsigned long mask_fcr31_x(unsigned long fcr31)
91 {
92 	return fcr31 & (FPU_CSR_UNI_X |
93 			((fcr31 & FPU_CSR_ALL_E) <<
94 			 (ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E))));
95 }
96 
97 #endif /* _ASM_FPU_EMULATOR_H */
98