xref: /linux/arch/mips/include/asm/fpu_emulator.h (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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/break.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 	local_t emulated;
37 	local_t loads;
38 	local_t stores;
39 	local_t cp1ops;
40 	local_t cp1xops;
41 	local_t errors;
42 	local_t ieee754_inexact;
43 	local_t ieee754_underflow;
44 	local_t ieee754_overflow;
45 	local_t ieee754_zerodiv;
46 	local_t ieee754_invalidop;
47 };
48 
49 DECLARE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats);
50 
51 #define MIPS_FPU_EMU_INC_STATS(M)					\
52 do {									\
53 	preempt_disable();						\
54 	__local_inc(&__get_cpu_var(fpuemustats).M);			\
55 	preempt_enable();						\
56 } while (0)
57 
58 #else
59 #define MIPS_FPU_EMU_INC_STATS(M) do { } while (0)
60 #endif /* CONFIG_DEBUG_FS */
61 
62 extern int mips_dsemul(struct pt_regs *regs, mips_instruction ir,
63 	unsigned long cpc);
64 extern int do_dsemulret(struct pt_regs *xcp);
65 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
66 				    struct mips_fpu_struct *ctx, int has_fpu,
67 				    void *__user *fault_addr);
68 int process_fpemu_return(int sig, void __user *fault_addr);
69 int mm_isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
70 		     unsigned long *contpc);
71 
72 /*
73  * Instruction inserted following the badinst to further tag the sequence
74  */
75 #define BD_COOKIE 0x0000bd36	/* tne $0, $0 with baggage */
76 
77 /*
78  * Break instruction with special math emu break code set
79  */
80 #define BREAK_MATH (0x0000000d | (BRK_MEMU << 16))
81 
82 #define SIGNALLING_NAN 0x7ff800007ff80000LL
83 
84 static inline void fpu_emulator_init_fpu(void)
85 {
86 	struct task_struct *t = current;
87 	int i;
88 
89 	t->thread.fpu.fcr31 = 0;
90 
91 	for (i = 0; i < 32; i++)
92 		set_fpr64(&t->thread.fpu.fpr[i], 0, SIGNALLING_NAN);
93 }
94 
95 #endif /* _ASM_FPU_EMULATOR_H */
96