Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
[linux-2.6] / arch / powerpc / kernel / softemu8xx.c
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 *)&current->thread.TS_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, &current->thread.TS_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 }