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5dd57a13 SW |
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> | |
5dd57a13 SW |
26 | #include <linux/interrupt.h> |
27 | ||
28 | #include <asm/pgtable.h> | |
29 | #include <asm/uaccess.h> | |
30 | #include <asm/system.h> | |
31 | #include <asm/io.h> | |
32 | ||
33 | /* Eventually we may need a look-up table, but this works for now. | |
34 | */ | |
35 | #define LFS 48 | |
36 | #define LFD 50 | |
37 | #define LFDU 51 | |
38 | #define STFD 54 | |
39 | #define STFDU 55 | |
40 | #define FMR 63 | |
41 | ||
42 | void print_8xx_pte(struct mm_struct *mm, unsigned long addr) | |
43 | { | |
44 | pgd_t *pgd; | |
45 | pmd_t *pmd; | |
46 | pte_t *pte; | |
47 | ||
48 | printk(" pte @ 0x%8lx: ", addr); | |
49 | pgd = pgd_offset(mm, addr & PAGE_MASK); | |
50 | if (pgd) { | |
51 | pmd = pmd_offset(pud_offset(pgd, addr & PAGE_MASK), | |
52 | addr & PAGE_MASK); | |
53 | if (pmd && pmd_present(*pmd)) { | |
54 | pte = pte_offset_kernel(pmd, addr & PAGE_MASK); | |
55 | if (pte) { | |
56 | printk(" (0x%08lx)->(0x%08lx)->0x%08lx\n", | |
57 | (long)pgd, (long)pte, (long)pte_val(*pte)); | |
58 | #define pp ((long)pte_val(*pte)) | |
59 | printk(" RPN: %05lx PP: %lx SPS: %lx SH: %lx " | |
60 | "CI: %lx v: %lx\n", | |
61 | pp>>12, /* rpn */ | |
62 | (pp>>10)&3, /* pp */ | |
63 | (pp>>3)&1, /* small */ | |
64 | (pp>>2)&1, /* shared */ | |
65 | (pp>>1)&1, /* cache inhibit */ | |
66 | pp&1 /* valid */ | |
67 | ); | |
68 | #undef pp | |
69 | } | |
70 | else { | |
71 | printk("no pte\n"); | |
72 | } | |
73 | } | |
74 | else { | |
75 | printk("no pmd\n"); | |
76 | } | |
77 | } | |
78 | else { | |
79 | printk("no pgd\n"); | |
80 | } | |
81 | } | |
82 | ||
83 | int get_8xx_pte(struct mm_struct *mm, unsigned long addr) | |
84 | { | |
85 | pgd_t *pgd; | |
86 | pmd_t *pmd; | |
87 | pte_t *pte; | |
88 | int retval = 0; | |
89 | ||
90 | pgd = pgd_offset(mm, addr & PAGE_MASK); | |
91 | if (pgd) { | |
92 | pmd = pmd_offset(pud_offset(pgd, addr & PAGE_MASK), | |
93 | addr & PAGE_MASK); | |
94 | if (pmd && pmd_present(*pmd)) { | |
95 | pte = pte_offset_kernel(pmd, addr & PAGE_MASK); | |
96 | if (pte) { | |
97 | retval = (int)pte_val(*pte); | |
98 | } | |
99 | } | |
100 | } | |
101 | return retval; | |
102 | } | |
103 | ||
104 | /* | |
105 | * We return 0 on success, 1 on unimplemented instruction, and EFAULT | |
106 | * if a load/store faulted. | |
107 | */ | |
108 | int Soft_emulate_8xx(struct pt_regs *regs) | |
109 | { | |
110 | u32 inst, instword; | |
111 | u32 flreg, idxreg, disp; | |
112 | int retval; | |
113 | s16 sdisp; | |
114 | u32 *ea, *ip; | |
115 | ||
116 | retval = 0; | |
117 | ||
118 | instword = *((u32 *)regs->nip); | |
119 | inst = instword >> 26; | |
120 | ||
121 | flreg = (instword >> 21) & 0x1f; | |
122 | idxreg = (instword >> 16) & 0x1f; | |
123 | disp = instword & 0xffff; | |
124 | ||
125 | ea = (u32 *)(regs->gpr[idxreg] + disp); | |
9c75a31c | 126 | ip = (u32 *)¤t->thread.TS_FPR(flreg); |
5dd57a13 SW |
127 | |
128 | switch ( inst ) | |
129 | { | |
130 | case LFD: | |
131 | /* this is a 16 bit quantity that is sign extended | |
132 | * so use a signed short here -- Cort | |
133 | */ | |
134 | sdisp = (instword & 0xffff); | |
135 | ea = (u32 *)(regs->gpr[idxreg] + sdisp); | |
136 | if (copy_from_user(ip, ea, sizeof(double))) | |
137 | retval = -EFAULT; | |
138 | break; | |
139 | ||
140 | case LFDU: | |
141 | if (copy_from_user(ip, ea, sizeof(double))) | |
142 | retval = -EFAULT; | |
143 | else | |
144 | regs->gpr[idxreg] = (u32)ea; | |
145 | break; | |
146 | case LFS: | |
147 | sdisp = (instword & 0xffff); | |
148 | ea = (u32 *)(regs->gpr[idxreg] + sdisp); | |
149 | if (copy_from_user(ip, ea, sizeof(float))) | |
150 | retval = -EFAULT; | |
151 | break; | |
152 | case STFD: | |
153 | /* this is a 16 bit quantity that is sign extended | |
154 | * so use a signed short here -- Cort | |
155 | */ | |
156 | sdisp = (instword & 0xffff); | |
157 | ea = (u32 *)(regs->gpr[idxreg] + sdisp); | |
158 | if (copy_to_user(ea, ip, sizeof(double))) | |
159 | retval = -EFAULT; | |
160 | break; | |
161 | ||
162 | case STFDU: | |
163 | if (copy_to_user(ea, ip, sizeof(double))) | |
164 | retval = -EFAULT; | |
165 | else | |
166 | regs->gpr[idxreg] = (u32)ea; | |
167 | break; | |
168 | case FMR: | |
169 | /* assume this is a fp move -- Cort */ | |
9c75a31c | 170 | memcpy(ip, ¤t->thread.TS_FPR((instword>>11)&0x1f), |
5dd57a13 SW |
171 | sizeof(double)); |
172 | break; | |
173 | default: | |
174 | retval = 1; | |
175 | printk("Bad emulation %s/%d\n" | |
176 | " NIP: %08lx instruction: %08x opcode: %x " | |
177 | "A: %x B: %x C: %x code: %x rc: %x\n", | |
178 | current->comm,current->pid, | |
179 | regs->nip, | |
180 | instword,inst, | |
181 | (instword>>16)&0x1f, | |
182 | (instword>>11)&0x1f, | |
183 | (instword>>6)&0x1f, | |
184 | (instword>>1)&0x3ff, | |
185 | instword&1); | |
186 | { | |
187 | int pa; | |
188 | print_8xx_pte(current->mm,regs->nip); | |
189 | pa = get_8xx_pte(current->mm,regs->nip) & PAGE_MASK; | |
190 | pa |= (regs->nip & ~PAGE_MASK); | |
191 | pa = (unsigned long)__va(pa); | |
192 | printk("Kernel VA for NIP %x ", pa); | |
193 | print_8xx_pte(current->mm,pa); | |
194 | } | |
195 | } | |
196 | ||
197 | if (retval == 0) | |
198 | regs->nip += 4; | |
199 | ||
200 | return retval; | |
201 | } |