2 * Software emulation of some PPC instructions for the 8xx core.
4 * Copyright (C) 1998 Dan Malek (dmalek@jlc.net)
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.
13 * For this emulation, our working registers are found on the register
17 #include <linux/errno.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
21 #include <linux/stddef.h>
22 #include <linux/unistd.h>
23 #include <linux/ptrace.h>
24 #include <linux/user.h>
25 #include <linux/interrupt.h>
27 #include <asm/pgtable.h>
28 #include <asm/uaccess.h>
29 #include <asm/system.h>
32 /* Eventually we may need a look-up table, but this works for now.
41 void print_8xx_pte(struct mm_struct
*mm
, unsigned long addr
)
47 printk(" pte @ 0x%8lx: ", addr
);
48 pgd
= pgd_offset(mm
, addr
& PAGE_MASK
);
50 pmd
= pmd_offset(pud_offset(pgd
, addr
& PAGE_MASK
),
52 if (pmd
&& pmd_present(*pmd
)) {
53 pte
= pte_offset_kernel(pmd
, addr
& PAGE_MASK
);
55 printk(" (0x%08lx)->(0x%08lx)->0x%08lx\n",
56 (long)pgd
, (long)pte
, (long)pte_val(*pte
));
57 #define pp ((long)pte_val(*pte))
58 printk(" RPN: %05lx PP: %lx SPS: %lx SH: %lx "
62 (pp
>>3)&1, /* small */
63 (pp
>>2)&1, /* shared */
64 (pp
>>1)&1, /* cache inhibit */
82 int get_8xx_pte(struct mm_struct
*mm
, unsigned long addr
)
89 pgd
= pgd_offset(mm
, addr
& PAGE_MASK
);
91 pmd
= pmd_offset(pud_offset(pgd
, addr
& PAGE_MASK
),
93 if (pmd
&& pmd_present(*pmd
)) {
94 pte
= pte_offset_kernel(pmd
, addr
& PAGE_MASK
);
96 retval
= (int)pte_val(*pte
);
104 * We return 0 on success, 1 on unimplemented instruction, and EFAULT
105 * if a load/store faulted.
107 int Soft_emulate_8xx(struct pt_regs
*regs
)
110 u32 flreg
, idxreg
, disp
;
117 instword
= *((u32
*)regs
->nip
);
118 inst
= instword
>> 26;
120 flreg
= (instword
>> 21) & 0x1f;
121 idxreg
= (instword
>> 16) & 0x1f;
122 disp
= instword
& 0xffff;
124 ea
= (u32
*)(regs
->gpr
[idxreg
] + disp
);
125 ip
= (u32
*)¤t
->thread
.TS_FPR(flreg
);
130 /* this is a 16 bit quantity that is sign extended
131 * so use a signed short here -- Cort
133 sdisp
= (instword
& 0xffff);
134 ea
= (u32
*)(regs
->gpr
[idxreg
] + sdisp
);
135 if (copy_from_user(ip
, ea
, sizeof(double)))
140 if (copy_from_user(ip
, ea
, sizeof(double)))
143 regs
->gpr
[idxreg
] = (u32
)ea
;
146 sdisp
= (instword
& 0xffff);
147 ea
= (u32
*)(regs
->gpr
[idxreg
] + sdisp
);
148 if (copy_from_user(ip
, ea
, sizeof(float)))
152 /* this is a 16 bit quantity that is sign extended
153 * so use a signed short here -- Cort
155 sdisp
= (instword
& 0xffff);
156 ea
= (u32
*)(regs
->gpr
[idxreg
] + sdisp
);
157 if (copy_to_user(ea
, ip
, sizeof(double)))
162 if (copy_to_user(ea
, ip
, sizeof(double)))
165 regs
->gpr
[idxreg
] = (u32
)ea
;
168 /* assume this is a fp move -- Cort */
169 memcpy(ip
, ¤t
->thread
.TS_FPR((instword
>>11)&0x1f),
174 printk("Bad emulation %s/%d\n"
175 " NIP: %08lx instruction: %08x opcode: %x "
176 "A: %x B: %x C: %x code: %x rc: %x\n",
177 current
->comm
,current
->pid
,
187 print_8xx_pte(current
->mm
,regs
->nip
);
188 pa
= get_8xx_pte(current
->mm
,regs
->nip
) & PAGE_MASK
;
189 pa
|= (regs
->nip
& ~PAGE_MASK
);
190 pa
= (unsigned long)__va(pa
);
191 printk("Kernel VA for NIP %x ", pa
);
192 print_8xx_pte(current
->mm
,pa
);
This page took 0.034193 seconds and 5 git commands to generate.