Commit | Line | Data |
---|---|---|
88278ca2 | 1 | /* |
1da177e4 LT |
2 | * muldiv.c: Hardware multiply/division illegal instruction trap |
3 | * for sun4c/sun4 (which do not have those instructions) | |
4 | * | |
5 | * Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz) | |
6 | * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) | |
7 | * | |
8 | * 2004-12-25 Krzysztof Helt (krzysztof.h1@wp.pl) | |
9 | * - fixed registers constrains in inline assembly declarations | |
10 | */ | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/mm.h> | |
15 | #include <asm/ptrace.h> | |
16 | #include <asm/processor.h> | |
17 | #include <asm/system.h> | |
18 | #include <asm/uaccess.h> | |
19 | ||
20 | /* #define DEBUG_MULDIV */ | |
21 | ||
22 | static inline int has_imm13(int insn) | |
23 | { | |
24 | return (insn & 0x2000); | |
25 | } | |
26 | ||
27 | static inline int is_foocc(int insn) | |
28 | { | |
29 | return (insn & 0x800000); | |
30 | } | |
31 | ||
32 | static inline int sign_extend_imm13(int imm) | |
33 | { | |
34 | return imm << 19 >> 19; | |
35 | } | |
36 | ||
37 | static inline void advance(struct pt_regs *regs) | |
38 | { | |
39 | regs->pc = regs->npc; | |
40 | regs->npc += 4; | |
41 | } | |
42 | ||
43 | static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2, | |
44 | unsigned int rd) | |
45 | { | |
46 | if(rs2 >= 16 || rs1 >= 16 || rd >= 16) { | |
47 | /* Wheee... */ | |
48 | __asm__ __volatile__("save %sp, -0x40, %sp\n\t" | |
49 | "save %sp, -0x40, %sp\n\t" | |
50 | "save %sp, -0x40, %sp\n\t" | |
51 | "save %sp, -0x40, %sp\n\t" | |
52 | "save %sp, -0x40, %sp\n\t" | |
53 | "save %sp, -0x40, %sp\n\t" | |
54 | "save %sp, -0x40, %sp\n\t" | |
55 | "restore; restore; restore; restore;\n\t" | |
56 | "restore; restore; restore;\n\t"); | |
57 | } | |
58 | } | |
59 | ||
60 | #define fetch_reg(reg, regs) ({ \ | |
61 | struct reg_window __user *win; \ | |
62 | register unsigned long ret; \ | |
63 | \ | |
64 | if (!(reg)) ret = 0; \ | |
65 | else if ((reg) < 16) { \ | |
66 | ret = regs->u_regs[(reg)]; \ | |
67 | } else { \ | |
68 | /* Ho hum, the slightly complicated case. */ \ | |
69 | win = (struct reg_window __user *)regs->u_regs[UREG_FP];\ | |
70 | if (get_user (ret, &win->locals[(reg) - 16])) return -1;\ | |
71 | } \ | |
72 | ret; \ | |
73 | }) | |
74 | ||
75 | static inline int | |
76 | store_reg(unsigned int result, unsigned int reg, struct pt_regs *regs) | |
77 | { | |
78 | struct reg_window __user *win; | |
79 | ||
80 | if (!reg) | |
81 | return 0; | |
82 | if (reg < 16) { | |
83 | regs->u_regs[reg] = result; | |
84 | return 0; | |
85 | } else { | |
86 | /* need to use put_user() in this case: */ | |
87 | win = (struct reg_window __user *) regs->u_regs[UREG_FP]; | |
88 | return (put_user(result, &win->locals[reg - 16])); | |
89 | } | |
90 | } | |
91 | ||
92 | extern void handle_hw_divzero (struct pt_regs *regs, unsigned long pc, | |
93 | unsigned long npc, unsigned long psr); | |
94 | ||
95 | /* Should return 0 if mul/div emulation succeeded and SIGILL should | |
96 | * not be issued. | |
97 | */ | |
98 | int do_user_muldiv(struct pt_regs *regs, unsigned long pc) | |
99 | { | |
100 | unsigned int insn; | |
101 | int inst; | |
102 | unsigned int rs1, rs2, rdv; | |
103 | ||
104 | if (!pc) | |
105 | return -1; /* This happens to often, I think */ | |
106 | if (get_user (insn, (unsigned int __user *)pc)) | |
107 | return -1; | |
108 | if ((insn & 0xc1400000) != 0x80400000) | |
109 | return -1; | |
110 | inst = ((insn >> 19) & 0xf); | |
111 | if ((inst & 0xe) != 10 && (inst & 0xe) != 14) | |
112 | return -1; | |
113 | ||
114 | /* Now we know we have to do something with umul, smul, udiv or sdiv */ | |
115 | rs1 = (insn >> 14) & 0x1f; | |
116 | rs2 = insn & 0x1f; | |
117 | rdv = (insn >> 25) & 0x1f; | |
118 | if (has_imm13(insn)) { | |
119 | maybe_flush_windows(rs1, 0, rdv); | |
120 | rs2 = sign_extend_imm13(insn); | |
121 | } else { | |
122 | maybe_flush_windows(rs1, rs2, rdv); | |
123 | rs2 = fetch_reg(rs2, regs); | |
124 | } | |
125 | rs1 = fetch_reg(rs1, regs); | |
126 | switch (inst) { | |
127 | case 10: /* umul */ | |
128 | #ifdef DEBUG_MULDIV | |
129 | printk ("unsigned muldiv: 0x%x * 0x%x = ", rs1, rs2); | |
130 | #endif | |
131 | __asm__ __volatile__ ("\n\t" | |
132 | "mov %0, %%o0\n\t" | |
133 | "call .umul\n\t" | |
134 | " mov %1, %%o1\n\t" | |
135 | "mov %%o0, %0\n\t" | |
136 | "mov %%o1, %1\n\t" | |
137 | : "=r" (rs1), "=r" (rs2) | |
138 | : "0" (rs1), "1" (rs2) | |
139 | : "o0", "o1", "o2", "o3", "o4", "o5", "o7", "cc"); | |
140 | #ifdef DEBUG_MULDIV | |
141 | printk ("0x%x%08x\n", rs2, rs1); | |
142 | #endif | |
143 | if (store_reg(rs1, rdv, regs)) | |
144 | return -1; | |
145 | regs->y = rs2; | |
146 | break; | |
147 | case 11: /* smul */ | |
148 | #ifdef DEBUG_MULDIV | |
149 | printk ("signed muldiv: 0x%x * 0x%x = ", rs1, rs2); | |
150 | #endif | |
151 | __asm__ __volatile__ ("\n\t" | |
152 | "mov %0, %%o0\n\t" | |
153 | "call .mul\n\t" | |
154 | " mov %1, %%o1\n\t" | |
155 | "mov %%o0, %0\n\t" | |
156 | "mov %%o1, %1\n\t" | |
157 | : "=r" (rs1), "=r" (rs2) | |
158 | : "0" (rs1), "1" (rs2) | |
159 | : "o0", "o1", "o2", "o3", "o4", "o5", "o7", "cc"); | |
160 | #ifdef DEBUG_MULDIV | |
161 | printk ("0x%x%08x\n", rs2, rs1); | |
162 | #endif | |
163 | if (store_reg(rs1, rdv, regs)) | |
164 | return -1; | |
165 | regs->y = rs2; | |
166 | break; | |
167 | case 14: /* udiv */ | |
168 | #ifdef DEBUG_MULDIV | |
169 | printk ("unsigned muldiv: 0x%x%08x / 0x%x = ", regs->y, rs1, rs2); | |
170 | #endif | |
171 | if (!rs2) { | |
172 | #ifdef DEBUG_MULDIV | |
173 | printk ("DIVISION BY ZERO\n"); | |
174 | #endif | |
175 | handle_hw_divzero (regs, pc, regs->npc, regs->psr); | |
176 | return 0; | |
177 | } | |
178 | __asm__ __volatile__ ("\n\t" | |
179 | "mov %2, %%o0\n\t" | |
180 | "mov %0, %%o1\n\t" | |
181 | "mov %%g0, %%o2\n\t" | |
182 | "call __udivdi3\n\t" | |
183 | " mov %1, %%o3\n\t" | |
184 | "mov %%o1, %0\n\t" | |
185 | "mov %%o0, %1\n\t" | |
186 | : "=r" (rs1), "=r" (rs2) | |
187 | : "r" (regs->y), "0" (rs1), "1" (rs2) | |
188 | : "o0", "o1", "o2", "o3", "o4", "o5", "o7", | |
189 | "g1", "g2", "g3", "cc"); | |
190 | #ifdef DEBUG_MULDIV | |
191 | printk ("0x%x\n", rs1); | |
192 | #endif | |
193 | if (store_reg(rs1, rdv, regs)) | |
194 | return -1; | |
195 | break; | |
196 | case 15: /* sdiv */ | |
197 | #ifdef DEBUG_MULDIV | |
198 | printk ("signed muldiv: 0x%x%08x / 0x%x = ", regs->y, rs1, rs2); | |
199 | #endif | |
200 | if (!rs2) { | |
201 | #ifdef DEBUG_MULDIV | |
202 | printk ("DIVISION BY ZERO\n"); | |
203 | #endif | |
204 | handle_hw_divzero (regs, pc, regs->npc, regs->psr); | |
205 | return 0; | |
206 | } | |
207 | __asm__ __volatile__ ("\n\t" | |
208 | "mov %2, %%o0\n\t" | |
209 | "mov %0, %%o1\n\t" | |
210 | "mov %%g0, %%o2\n\t" | |
211 | "call __divdi3\n\t" | |
212 | " mov %1, %%o3\n\t" | |
213 | "mov %%o1, %0\n\t" | |
214 | "mov %%o0, %1\n\t" | |
215 | : "=r" (rs1), "=r" (rs2) | |
216 | : "r" (regs->y), "0" (rs1), "1" (rs2) | |
217 | : "o0", "o1", "o2", "o3", "o4", "o5", "o7", | |
218 | "g1", "g2", "g3", "cc"); | |
219 | #ifdef DEBUG_MULDIV | |
220 | printk ("0x%x\n", rs1); | |
221 | #endif | |
222 | if (store_reg(rs1, rdv, regs)) | |
223 | return -1; | |
224 | break; | |
225 | } | |
226 | if (is_foocc (insn)) { | |
227 | regs->psr &= ~PSR_ICC; | |
228 | if ((inst & 0xe) == 14) { | |
229 | /* ?div */ | |
230 | if (rs2) regs->psr |= PSR_V; | |
231 | } | |
232 | if (!rs1) regs->psr |= PSR_Z; | |
233 | if (((int)rs1) < 0) regs->psr |= PSR_N; | |
234 | #ifdef DEBUG_MULDIV | |
235 | printk ("psr muldiv: %08x\n", regs->psr); | |
236 | #endif | |
237 | } | |
238 | advance(regs); | |
239 | return 0; | |
240 | } |