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review.evervolv.com / android_kernel_oneplus_msm8996 / f10bb2544bab75b3e8df15a7b51a833c78cbd77f / . / arch / ppc / kernel / softemu8xx.c
blob: 9bbb6bf7b6459b643bf0afbe9f06d30432380313 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]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
34extern void
35print_8xx_pte(struct mm_struct *mm, unsigned long addr);
36extern int
37get_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 */
52int
53Soft_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 *)&current->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, &current->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