Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Software emulation of some PPC instructions for the 8xx core. | |
3 | * | |
4 | * Copyright (C) 1998 Dan Malek (dmalek@jlc.net) | |
5 | * | |
6 | * Software floating emuation for the MPC8xx processor. I did this mostly | |
7 | * because it was easier than trying to get the libraries compiled for | |
8 | * software floating point. The goal is still to get the libraries done, | |
9 | * but I lost patience and needed some hacks to at least get init and | |
10 | * shells running. The first problem is the setjmp/longjmp that save | |
11 | * and restore the floating point registers. | |
12 | * | |
13 | * For this emulation, our working registers are found on the register | |
14 | * save area. | |
15 | */ | |
16 | ||
17 | #include <linux/errno.h> | |
18 | #include <linux/sched.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/mm.h> | |
21 | #include <linux/stddef.h> | |
22 | #include <linux/unistd.h> | |
23 | #include <linux/ptrace.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/user.h> | |
26 | #include <linux/a.out.h> | |
27 | #include <linux/interrupt.h> | |
28 | ||
29 | #include <asm/pgtable.h> | |
30 | #include <asm/uaccess.h> | |
31 | #include <asm/system.h> | |
32 | #include <asm/io.h> | |
33 | ||
34 | extern void | |
35 | print_8xx_pte(struct mm_struct *mm, unsigned long addr); | |
36 | extern int | |
37 | get_8xx_pte(struct mm_struct *mm, unsigned long addr); | |
38 | ||
39 | /* Eventually we may need a look-up table, but this works for now. | |
40 | */ | |
41 | #define LFS 48 | |
42 | #define LFD 50 | |
43 | #define LFDU 51 | |
44 | #define STFD 54 | |
45 | #define STFDU 55 | |
46 | #define FMR 63 | |
47 | ||
48 | /* | |
49 | * We return 0 on success, 1 on unimplemented instruction, and EFAULT | |
50 | * if a load/store faulted. | |
51 | */ | |
52 | int | |
53 | Soft_emulate_8xx(struct pt_regs *regs) | |
54 | { | |
55 | uint inst, instword; | |
56 | uint flreg, idxreg, disp; | |
57 | uint retval; | |
58 | signed short sdisp; | |
59 | uint *ea, *ip; | |
60 | ||
61 | retval = 0; | |
62 | ||
63 | instword = *((uint *)regs->nip); | |
64 | inst = instword >> 26; | |
65 | ||
66 | flreg = (instword >> 21) & 0x1f; | |
67 | idxreg = (instword >> 16) & 0x1f; | |
68 | disp = instword & 0xffff; | |
69 | ||
70 | ea = (uint *)(regs->gpr[idxreg] + disp); | |
71 | ip = (uint *)¤t->thread.fpr[flreg]; | |
72 | ||
73 | switch ( inst ) | |
74 | { | |
75 | case LFD: | |
76 | /* this is a 16 bit quantity that is sign extended | |
77 | * so use a signed short here -- Cort | |
78 | */ | |
79 | sdisp = (instword & 0xffff); | |
80 | ea = (uint *)(regs->gpr[idxreg] + sdisp); | |
81 | if (copy_from_user(ip, ea, sizeof(double))) | |
82 | retval = -EFAULT; | |
83 | break; | |
84 | ||
85 | case LFDU: | |
86 | if (copy_from_user(ip, ea, sizeof(double))) | |
87 | retval = -EFAULT; | |
88 | else | |
89 | regs->gpr[idxreg] = (uint)ea; | |
90 | break; | |
91 | case LFS: | |
92 | sdisp = (instword & 0xffff); | |
93 | ea = (uint *)(regs->gpr[idxreg] + sdisp); | |
94 | if (copy_from_user(ip, ea, sizeof(float))) | |
95 | retval = -EFAULT; | |
96 | break; | |
97 | case STFD: | |
98 | /* this is a 16 bit quantity that is sign extended | |
99 | * so use a signed short here -- Cort | |
100 | */ | |
101 | sdisp = (instword & 0xffff); | |
102 | ea = (uint *)(regs->gpr[idxreg] + sdisp); | |
103 | if (copy_to_user(ea, ip, sizeof(double))) | |
104 | retval = -EFAULT; | |
105 | break; | |
106 | ||
107 | case STFDU: | |
108 | if (copy_to_user(ea, ip, sizeof(double))) | |
109 | retval = -EFAULT; | |
110 | else | |
111 | regs->gpr[idxreg] = (uint)ea; | |
112 | break; | |
113 | case FMR: | |
114 | /* assume this is a fp move -- Cort */ | |
115 | memcpy( ip, ¤t->thread.fpr[(instword>>11)&0x1f], | |
116 | sizeof(double) ); | |
117 | break; | |
118 | default: | |
119 | retval = 1; | |
120 | printk("Bad emulation %s/%d\n" | |
121 | " NIP: %08lx instruction: %08x opcode: %x " | |
122 | "A: %x B: %x C: %x code: %x rc: %x\n", | |
123 | current->comm,current->pid, | |
124 | regs->nip, | |
125 | instword,inst, | |
126 | (instword>>16)&0x1f, | |
127 | (instword>>11)&0x1f, | |
128 | (instword>>6)&0x1f, | |
129 | (instword>>1)&0x3ff, | |
130 | instword&1); | |
131 | { | |
132 | int pa; | |
133 | print_8xx_pte(current->mm,regs->nip); | |
134 | pa = get_8xx_pte(current->mm,regs->nip) & PAGE_MASK; | |
135 | pa |= (regs->nip & ~PAGE_MASK); | |
136 | pa = (unsigned long)__va(pa); | |
137 | printk("Kernel VA for NIP %x ", pa); | |
138 | print_8xx_pte(current->mm,pa); | |
139 | } | |
140 | ||
141 | } | |
142 | ||
143 | if (retval == 0) | |
144 | regs->nip += 4; | |
145 | return(retval); | |
146 | } | |
147 |