1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3
4 #include <linux/ptrace.h>
5 #include <linux/uaccess.h>
6 #include <abi/reg_ops.h>
7
8 #define MTCR_MASK 0xFC00FFE0
9 #define MFCR_MASK 0xFC00FFE0
10 #define MTCR_DIST 0xC0006420
11 #define MFCR_DIST 0xC0006020
12
13 /*
14 * fpu_libc_helper() is to help libc to excute:
15 * - mfcr %a, cr<1, 2>
16 * - mfcr %a, cr<2, 2>
17 * - mtcr %a, cr<1, 2>
18 * - mtcr %a, cr<2, 2>
19 */
20 int fpu_libc_helper(struct pt_regs *regs)
21 {
22 int fault;
23 unsigned long instrptr, regx = 0;
24 unsigned long index = 0, tmp = 0;
25 unsigned long tinstr = 0;
26 u16 instr_hi, instr_low;
27
28 instrptr = instruction_pointer(regs);
29 if (instrptr & 1)
30 return 0;
31
32 fault = __get_user(instr_low, (u16 *)instrptr);
33 if (fault)
34 return 0;
35
36 fault = __get_user(instr_hi, (u16 *)(instrptr + 2));
37 if (fault)
38 return 0;
39
40 tinstr = instr_hi | ((unsigned long)instr_low << 16);
41
42 if (((tinstr >> 21) & 0x1F) != 2)
43 return 0;
44
45 if ((tinstr & MTCR_MASK) == MTCR_DIST) {
46 index = (tinstr >> 16) & 0x1F;
47 if (index > 13)
48 return 0;
49
50 tmp = tinstr & 0x1F;
51 if (tmp > 2)
52 return 0;
53
54 regx = *(®s->a0 + index);
55
56 if (tmp == 1)
57 mtcr("cr<1, 2>", regx);
58 else if (tmp == 2)
59 mtcr("cr<2, 2>", regx);
60 else
61 return 0;
62
63 regs->pc += 4;
64 return 1;
65 }
66
67 if ((tinstr & MFCR_MASK) == MFCR_DIST) {
68 index = tinstr & 0x1F;
69 if (index > 13)
70 return 0;
71
72 tmp = ((tinstr >> 16) & 0x1F);
73 if (tmp > 2)
74 return 0;
75
76 if (tmp == 1)
77 regx = mfcr("cr<1, 2>");
78 else if (tmp == 2)
79 regx = mfcr("cr<2, 2>");
80 else
81 return 0;
82
83 *(®s->a0 + index) = regx;
84
85 regs->pc += 4;
86 return 1;
87 }
88
89 return 0;
90 }
91
92 void fpu_fpe(struct pt_regs *regs)
93 {
94 int sig, code;
95 unsigned int fesr;
96
97 fesr = mfcr("cr<2, 2>");
98
99 sig = SIGFPE;
100 code = FPE_FLTUNK;
101
102 if (fesr & FPE_ILLE) {
103 sig = SIGILL;
104 code = ILL_ILLOPC;
105 } else if (fesr & FPE_IDC) {
106 sig = SIGILL;
107 code = ILL_ILLOPN;
108 } else if (fesr & FPE_FEC) {
109 sig = SIGFPE;
110 if (fesr & FPE_IOC)
111 code = FPE_FLTINV;
112 else if (fesr & FPE_DZC)
113 code = FPE_FLTDIV;
114 else if (fesr & FPE_UFC)
115 code = FPE_FLTUND;
116 else if (fesr & FPE_OFC)
117 code = FPE_FLTOVF;
118 else if (fesr & FPE_IXC)
119 code = FPE_FLTRES;
120 }
121
122 force_sig_fault(sig, code, (void __user *)regs->pc);
123 }
124
125 #define FMFVR_FPU_REGS(vrx, vry) \
126 "fmfvrl %0, "#vrx"\n" \
127 "fmfvrh %1, "#vrx"\n" \
128 "fmfvrl %2, "#vry"\n" \
129 "fmfvrh %3, "#vry"\n"
130
131 #define FMTVR_FPU_REGS(vrx, vry) \
132 "fmtvrl "#vrx", %0\n" \
133 "fmtvrh "#vrx", %1\n" \
134 "fmtvrl "#vry", %2\n" \
135 "fmtvrh "#vry", %3\n"
136
137 #define STW_FPU_REGS(a, b, c, d) \
138 "stw %0, (%4, "#a")\n" \
139 "stw %1, (%4, "#b")\n" \
140 "stw %2, (%4, "#c")\n" \
141 "stw %3, (%4, "#d")\n"
142
143 #define LDW_FPU_REGS(a, b, c, d) \
144 "ldw %0, (%4, "#a")\n" \
145 "ldw %1, (%4, "#b")\n" \
146 "ldw %2, (%4, "#c")\n" \
147 "ldw %3, (%4, "#d")\n"
148
149 void save_to_user_fp(struct user_fp *user_fp)
150 {
151 unsigned long flg;
152 unsigned long tmp1, tmp2;
153 unsigned long *fpregs;
154
155 local_irq_save(flg);
156
157 tmp1 = mfcr("cr<1, 2>");
158 tmp2 = mfcr("cr<2, 2>");
159
160 user_fp->fcr = tmp1;
161 user_fp->fesr = tmp2;
162
163 fpregs = &user_fp->vr[0];
164 #ifdef CONFIG_CPU_HAS_FPUV2
165 #ifdef CONFIG_CPU_HAS_VDSP
166 asm volatile(
167 "vstmu.32 vr0-vr3, (%0)\n"
168 "vstmu.32 vr4-vr7, (%0)\n"
169 "vstmu.32 vr8-vr11, (%0)\n"
170 "vstmu.32 vr12-vr15, (%0)\n"
171 "fstmu.64 vr16-vr31, (%0)\n"
172 : "+a"(fpregs)
173 ::"memory");
174 #else
175 asm volatile(
176 "fstmu.64 vr0-vr31, (%0)\n"
177 : "+a"(fpregs)
178 ::"memory");
179 #endif
180 #else
181 {
182 unsigned long tmp3, tmp4;
183
184 asm volatile(
185 FMFVR_FPU_REGS(vr0, vr1)
186 STW_FPU_REGS(0, 4, 16, 20)
187 FMFVR_FPU_REGS(vr2, vr3)
188 STW_FPU_REGS(32, 36, 48, 52)
189 FMFVR_FPU_REGS(vr4, vr5)
190 STW_FPU_REGS(64, 68, 80, 84)
191 FMFVR_FPU_REGS(vr6, vr7)
192 STW_FPU_REGS(96, 100, 112, 116)
193 "addi %4, 128\n"
194 FMFVR_FPU_REGS(vr8, vr9)
195 STW_FPU_REGS(0, 4, 16, 20)
196 FMFVR_FPU_REGS(vr10, vr11)
197 STW_FPU_REGS(32, 36, 48, 52)
198 FMFVR_FPU_REGS(vr12, vr13)
199 STW_FPU_REGS(64, 68, 80, 84)
200 FMFVR_FPU_REGS(vr14, vr15)
201 STW_FPU_REGS(96, 100, 112, 116)
202 : "=a"(tmp1), "=a"(tmp2), "=a"(tmp3),
203 "=a"(tmp4), "+a"(fpregs)
204 ::"memory");
205 }
206 #endif
207
208 local_irq_restore(flg);
209 }
210
211 void restore_from_user_fp(struct user_fp *user_fp)
212 {
213 unsigned long flg;
214 unsigned long tmp1, tmp2;
215 unsigned long *fpregs;
216
217 local_irq_save(flg);
218
219 tmp1 = user_fp->fcr;
220 tmp2 = user_fp->fesr;
221
222 mtcr("cr<1, 2>", tmp1);
223 mtcr("cr<2, 2>", tmp2);
224
225 fpregs = &user_fp->vr[0];
226 #ifdef CONFIG_CPU_HAS_FPUV2
227 #ifdef CONFIG_CPU_HAS_VDSP
228 asm volatile(
229 "vldmu.32 vr0-vr3, (%0)\n"
230 "vldmu.32 vr4-vr7, (%0)\n"
231 "vldmu.32 vr8-vr11, (%0)\n"
232 "vldmu.32 vr12-vr15, (%0)\n"
233 "fldmu.64 vr16-vr31, (%0)\n"
234 : "+a"(fpregs)
235 ::"memory");
236 #else
237 asm volatile(
238 "fldmu.64 vr0-vr31, (%0)\n"
239 : "+a"(fpregs)
240 ::"memory");
241 #endif
242 #else
243 {
244 unsigned long tmp3, tmp4;
245
246 asm volatile(
247 LDW_FPU_REGS(0, 4, 16, 20)
248 FMTVR_FPU_REGS(vr0, vr1)
249 LDW_FPU_REGS(32, 36, 48, 52)
250 FMTVR_FPU_REGS(vr2, vr3)
251 LDW_FPU_REGS(64, 68, 80, 84)
252 FMTVR_FPU_REGS(vr4, vr5)
253 LDW_FPU_REGS(96, 100, 112, 116)
254 FMTVR_FPU_REGS(vr6, vr7)
255 "addi %4, 128\n"
256 LDW_FPU_REGS(0, 4, 16, 20)
257 FMTVR_FPU_REGS(vr8, vr9)
258 LDW_FPU_REGS(32, 36, 48, 52)
259 FMTVR_FPU_REGS(vr10, vr11)
260 LDW_FPU_REGS(64, 68, 80, 84)
261 FMTVR_FPU_REGS(vr12, vr13)
262 LDW_FPU_REGS(96, 100, 112, 116)
263 FMTVR_FPU_REGS(vr14, vr15)
264 : "=a"(tmp1), "=a"(tmp2), "=a"(tmp3),
265 "=a"(tmp4), "+a"(fpregs)
266 ::"memory");
267 }
268 #endif
269 local_irq_restore(flg);
270 }
271
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