Scott Wood | 5dd57a1 | 2007-09-18 15:29:35 -0500 | [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> |
Scott Wood | 5dd57a1 | 2007-09-18 15:29:35 -0500 | [diff] [blame] | 24 | #include <linux/user.h> |
Scott Wood | 5dd57a1 | 2007-09-18 15:29:35 -0500 | [diff] [blame] | 25 | #include <linux/interrupt.h> |
| 26 | |
| 27 | #include <asm/pgtable.h> |
| 28 | #include <asm/uaccess.h> |
Scott Wood | 5dd57a1 | 2007-09-18 15:29:35 -0500 | [diff] [blame] | 29 | #include <asm/io.h> |
| 30 | |
| 31 | /* Eventually we may need a look-up table, but this works for now. |
| 32 | */ |
| 33 | #define LFS 48 |
| 34 | #define LFD 50 |
| 35 | #define LFDU 51 |
| 36 | #define STFD 54 |
| 37 | #define STFDU 55 |
| 38 | #define FMR 63 |
| 39 | |
| 40 | void print_8xx_pte(struct mm_struct *mm, unsigned long addr) |
| 41 | { |
| 42 | pgd_t *pgd; |
| 43 | pmd_t *pmd; |
| 44 | pte_t *pte; |
| 45 | |
| 46 | printk(" pte @ 0x%8lx: ", addr); |
| 47 | pgd = pgd_offset(mm, addr & PAGE_MASK); |
| 48 | if (pgd) { |
| 49 | pmd = pmd_offset(pud_offset(pgd, addr & PAGE_MASK), |
| 50 | addr & PAGE_MASK); |
| 51 | if (pmd && pmd_present(*pmd)) { |
| 52 | pte = pte_offset_kernel(pmd, addr & PAGE_MASK); |
| 53 | if (pte) { |
| 54 | printk(" (0x%08lx)->(0x%08lx)->0x%08lx\n", |
| 55 | (long)pgd, (long)pte, (long)pte_val(*pte)); |
| 56 | #define pp ((long)pte_val(*pte)) |
| 57 | printk(" RPN: %05lx PP: %lx SPS: %lx SH: %lx " |
| 58 | "CI: %lx v: %lx\n", |
| 59 | pp>>12, /* rpn */ |
| 60 | (pp>>10)&3, /* pp */ |
| 61 | (pp>>3)&1, /* small */ |
| 62 | (pp>>2)&1, /* shared */ |
| 63 | (pp>>1)&1, /* cache inhibit */ |
| 64 | pp&1 /* valid */ |
| 65 | ); |
| 66 | #undef pp |
| 67 | } |
| 68 | else { |
| 69 | printk("no pte\n"); |
| 70 | } |
| 71 | } |
| 72 | else { |
| 73 | printk("no pmd\n"); |
| 74 | } |
| 75 | } |
| 76 | else { |
| 77 | printk("no pgd\n"); |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | int get_8xx_pte(struct mm_struct *mm, unsigned long addr) |
| 82 | { |
| 83 | pgd_t *pgd; |
| 84 | pmd_t *pmd; |
| 85 | pte_t *pte; |
| 86 | int retval = 0; |
| 87 | |
| 88 | pgd = pgd_offset(mm, addr & PAGE_MASK); |
| 89 | if (pgd) { |
| 90 | pmd = pmd_offset(pud_offset(pgd, addr & PAGE_MASK), |
| 91 | addr & PAGE_MASK); |
| 92 | if (pmd && pmd_present(*pmd)) { |
| 93 | pte = pte_offset_kernel(pmd, addr & PAGE_MASK); |
| 94 | if (pte) { |
| 95 | retval = (int)pte_val(*pte); |
| 96 | } |
| 97 | } |
| 98 | } |
| 99 | return retval; |
| 100 | } |
| 101 | |
| 102 | /* |
| 103 | * We return 0 on success, 1 on unimplemented instruction, and EFAULT |
| 104 | * if a load/store faulted. |
| 105 | */ |
| 106 | int Soft_emulate_8xx(struct pt_regs *regs) |
| 107 | { |
| 108 | u32 inst, instword; |
| 109 | u32 flreg, idxreg, disp; |
| 110 | int retval; |
| 111 | s16 sdisp; |
| 112 | u32 *ea, *ip; |
| 113 | |
| 114 | retval = 0; |
| 115 | |
| 116 | instword = *((u32 *)regs->nip); |
| 117 | inst = instword >> 26; |
| 118 | |
| 119 | flreg = (instword >> 21) & 0x1f; |
| 120 | idxreg = (instword >> 16) & 0x1f; |
| 121 | disp = instword & 0xffff; |
| 122 | |
| 123 | ea = (u32 *)(regs->gpr[idxreg] + disp); |
Michael Neuling | 9c75a31 | 2008-06-26 17:07:48 +1000 | [diff] [blame] | 124 | ip = (u32 *)¤t->thread.TS_FPR(flreg); |
Scott Wood | 5dd57a1 | 2007-09-18 15:29:35 -0500 | [diff] [blame] | 125 | |
| 126 | switch ( inst ) |
| 127 | { |
| 128 | case LFD: |
| 129 | /* this is a 16 bit quantity that is sign extended |
| 130 | * so use a signed short here -- Cort |
| 131 | */ |
| 132 | sdisp = (instword & 0xffff); |
| 133 | ea = (u32 *)(regs->gpr[idxreg] + sdisp); |
| 134 | if (copy_from_user(ip, ea, sizeof(double))) |
| 135 | retval = -EFAULT; |
| 136 | break; |
| 137 | |
| 138 | case LFDU: |
| 139 | if (copy_from_user(ip, ea, sizeof(double))) |
| 140 | retval = -EFAULT; |
| 141 | else |
| 142 | regs->gpr[idxreg] = (u32)ea; |
| 143 | break; |
| 144 | case LFS: |
| 145 | sdisp = (instword & 0xffff); |
| 146 | ea = (u32 *)(regs->gpr[idxreg] + sdisp); |
| 147 | if (copy_from_user(ip, ea, sizeof(float))) |
| 148 | retval = -EFAULT; |
| 149 | break; |
| 150 | case STFD: |
| 151 | /* this is a 16 bit quantity that is sign extended |
| 152 | * so use a signed short here -- Cort |
| 153 | */ |
| 154 | sdisp = (instword & 0xffff); |
| 155 | ea = (u32 *)(regs->gpr[idxreg] + sdisp); |
| 156 | if (copy_to_user(ea, ip, sizeof(double))) |
| 157 | retval = -EFAULT; |
| 158 | break; |
| 159 | |
| 160 | case STFDU: |
| 161 | if (copy_to_user(ea, ip, sizeof(double))) |
| 162 | retval = -EFAULT; |
| 163 | else |
| 164 | regs->gpr[idxreg] = (u32)ea; |
| 165 | break; |
| 166 | case FMR: |
| 167 | /* assume this is a fp move -- Cort */ |
Michael Neuling | 9c75a31 | 2008-06-26 17:07:48 +1000 | [diff] [blame] | 168 | memcpy(ip, ¤t->thread.TS_FPR((instword>>11)&0x1f), |
Scott Wood | 5dd57a1 | 2007-09-18 15:29:35 -0500 | [diff] [blame] | 169 | sizeof(double)); |
| 170 | break; |
| 171 | default: |
| 172 | retval = 1; |
| 173 | printk("Bad emulation %s/%d\n" |
| 174 | " NIP: %08lx instruction: %08x opcode: %x " |
| 175 | "A: %x B: %x C: %x code: %x rc: %x\n", |
| 176 | current->comm,current->pid, |
| 177 | regs->nip, |
| 178 | instword,inst, |
| 179 | (instword>>16)&0x1f, |
| 180 | (instword>>11)&0x1f, |
| 181 | (instword>>6)&0x1f, |
| 182 | (instword>>1)&0x3ff, |
| 183 | instword&1); |
| 184 | { |
| 185 | int pa; |
| 186 | print_8xx_pte(current->mm,regs->nip); |
| 187 | pa = get_8xx_pte(current->mm,regs->nip) & PAGE_MASK; |
| 188 | pa |= (regs->nip & ~PAGE_MASK); |
| 189 | pa = (unsigned long)__va(pa); |
| 190 | printk("Kernel VA for NIP %x ", pa); |
| 191 | print_8xx_pte(current->mm,pa); |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | if (retval == 0) |
| 196 | regs->nip += 4; |
| 197 | |
| 198 | return retval; |
| 199 | } |