Commit | Line | Data |
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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> | |
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 | /* Eventually we may need a look-up table, but this works for now. | |
35 | */ | |
36 | #define LFS 48 | |
37 | #define LFD 50 | |
38 | #define LFDU 51 | |
39 | #define STFD 54 | |
40 | #define STFDU 55 | |
41 | #define FMR 63 | |
42 | ||
43 | void print_8xx_pte(struct mm_struct *mm, unsigned long addr) | |
44 | { | |
45 | pgd_t *pgd; | |
46 | pmd_t *pmd; | |
47 | pte_t *pte; | |
48 | ||
49 | printk(" pte @ 0x%8lx: ", addr); | |
50 | pgd = pgd_offset(mm, addr & PAGE_MASK); | |
51 | if (pgd) { | |
52 | pmd = pmd_offset(pud_offset(pgd, addr & PAGE_MASK), | |
53 | addr & PAGE_MASK); | |
54 | if (pmd && pmd_present(*pmd)) { | |
55 | pte = pte_offset_kernel(pmd, addr & PAGE_MASK); | |
56 | if (pte) { | |
57 | printk(" (0x%08lx)->(0x%08lx)->0x%08lx\n", | |
58 | (long)pgd, (long)pte, (long)pte_val(*pte)); | |
59 | #define pp ((long)pte_val(*pte)) | |
60 | printk(" RPN: %05lx PP: %lx SPS: %lx SH: %lx " | |
61 | "CI: %lx v: %lx\n", | |
62 | pp>>12, /* rpn */ | |
63 | (pp>>10)&3, /* pp */ | |
64 | (pp>>3)&1, /* small */ | |
65 | (pp>>2)&1, /* shared */ | |
66 | (pp>>1)&1, /* cache inhibit */ | |
67 | pp&1 /* valid */ | |
68 | ); | |
69 | #undef pp | |
70 | } | |
71 | else { | |
72 | printk("no pte\n"); | |
73 | } | |
74 | } | |
75 | else { | |
76 | printk("no pmd\n"); | |
77 | } | |
78 | } | |
79 | else { | |
80 | printk("no pgd\n"); | |
81 | } | |
82 | } | |
83 | ||
84 | int get_8xx_pte(struct mm_struct *mm, unsigned long addr) | |
85 | { | |
86 | pgd_t *pgd; | |
87 | pmd_t *pmd; | |
88 | pte_t *pte; | |
89 | int retval = 0; | |
90 | ||
91 | pgd = pgd_offset(mm, addr & PAGE_MASK); | |
92 | if (pgd) { | |
93 | pmd = pmd_offset(pud_offset(pgd, addr & PAGE_MASK), | |
94 | addr & PAGE_MASK); | |
95 | if (pmd && pmd_present(*pmd)) { | |
96 | pte = pte_offset_kernel(pmd, addr & PAGE_MASK); | |
97 | if (pte) { | |
98 | retval = (int)pte_val(*pte); | |
99 | } | |
100 | } | |
101 | } | |
102 | return retval; | |
103 | } | |
104 | ||
105 | /* | |
106 | * We return 0 on success, 1 on unimplemented instruction, and EFAULT | |
107 | * if a load/store faulted. | |
108 | */ | |
109 | int Soft_emulate_8xx(struct pt_regs *regs) | |
110 | { | |
111 | u32 inst, instword; | |
112 | u32 flreg, idxreg, disp; | |
113 | int retval; | |
114 | s16 sdisp; | |
115 | u32 *ea, *ip; | |
116 | ||
117 | retval = 0; | |
118 | ||
119 | instword = *((u32 *)regs->nip); | |
120 | inst = instword >> 26; | |
121 | ||
122 | flreg = (instword >> 21) & 0x1f; | |
123 | idxreg = (instword >> 16) & 0x1f; | |
124 | disp = instword & 0xffff; | |
125 | ||
126 | ea = (u32 *)(regs->gpr[idxreg] + disp); | |
127 | ip = (u32 *)¤t->thread.fpr[flreg]; | |
128 | ||
129 | switch ( inst ) | |
130 | { | |
131 | case LFD: | |
132 | /* this is a 16 bit quantity that is sign extended | |
133 | * so use a signed short here -- Cort | |
134 | */ | |
135 | sdisp = (instword & 0xffff); | |
136 | ea = (u32 *)(regs->gpr[idxreg] + sdisp); | |
137 | if (copy_from_user(ip, ea, sizeof(double))) | |
138 | retval = -EFAULT; | |
139 | break; | |
140 | ||
141 | case LFDU: | |
142 | if (copy_from_user(ip, ea, sizeof(double))) | |
143 | retval = -EFAULT; | |
144 | else | |
145 | regs->gpr[idxreg] = (u32)ea; | |
146 | break; | |
147 | case LFS: | |
148 | sdisp = (instword & 0xffff); | |
149 | ea = (u32 *)(regs->gpr[idxreg] + sdisp); | |
150 | if (copy_from_user(ip, ea, sizeof(float))) | |
151 | retval = -EFAULT; | |
152 | break; | |
153 | case STFD: | |
154 | /* this is a 16 bit quantity that is sign extended | |
155 | * so use a signed short here -- Cort | |
156 | */ | |
157 | sdisp = (instword & 0xffff); | |
158 | ea = (u32 *)(regs->gpr[idxreg] + sdisp); | |
159 | if (copy_to_user(ea, ip, sizeof(double))) | |
160 | retval = -EFAULT; | |
161 | break; | |
162 | ||
163 | case STFDU: | |
164 | if (copy_to_user(ea, ip, sizeof(double))) | |
165 | retval = -EFAULT; | |
166 | else | |
167 | regs->gpr[idxreg] = (u32)ea; | |
168 | break; | |
169 | case FMR: | |
170 | /* assume this is a fp move -- Cort */ | |
171 | memcpy(ip, ¤t->thread.fpr[(instword>>11)&0x1f], | |
172 | sizeof(double)); | |
173 | break; | |
174 | default: | |
175 | retval = 1; | |
176 | printk("Bad emulation %s/%d\n" | |
177 | " NIP: %08lx instruction: %08x opcode: %x " | |
178 | "A: %x B: %x C: %x code: %x rc: %x\n", | |
179 | current->comm,current->pid, | |
180 | regs->nip, | |
181 | instword,inst, | |
182 | (instword>>16)&0x1f, | |
183 | (instword>>11)&0x1f, | |
184 | (instword>>6)&0x1f, | |
185 | (instword>>1)&0x3ff, | |
186 | instword&1); | |
187 | { | |
188 | int pa; | |
189 | print_8xx_pte(current->mm,regs->nip); | |
190 | pa = get_8xx_pte(current->mm,regs->nip) & PAGE_MASK; | |
191 | pa |= (regs->nip & ~PAGE_MASK); | |
192 | pa = (unsigned long)__va(pa); | |
193 | printk("Kernel VA for NIP %x ", pa); | |
194 | print_8xx_pte(current->mm,pa); | |
195 | } | |
196 | } | |
197 | ||
198 | if (retval == 0) | |
199 | regs->nip += 4; | |
200 | ||
201 | return retval; | |
202 | } |