1 /*
2  * Copyright (C) 2016-2017 Netronome Systems, Inc.
3  *
4  * This software is dual licensed under the GNU General License Version 2,
5  * June 1991 as shown in the file COPYING in the top-level directory of this
6  * source tree or the BSD 2-Clause License provided below.  You have the
7  * option to license this software under the complete terms of either license.
8  *
9  * The BSD 2-Clause License:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      1. Redistributions of source code must retain the above
16  *         copyright notice, this list of conditions and the following
17  *         disclaimer.
18  *
19  *      2. Redistributions in binary form must reproduce the above
20  *         copyright notice, this list of conditions and the following
21  *         disclaimer in the documentation and/or other materials
22  *         provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 #include <linux/bitops.h>
35 #include <linux/errno.h>
36 #include <linux/kernel.h>
37 #include <linux/string.h>
38 #include <linux/types.h>
39 
40 #include "nfp_asm.h"
41 
42 const struct cmd_tgt_act cmd_tgt_act[__CMD_TGT_MAP_SIZE] = {
43 	[CMD_TGT_WRITE8_SWAP] =		{ 0x02, 0x42 },
44 	[CMD_TGT_WRITE32_SWAP] =	{ 0x02, 0x5f },
45 	[CMD_TGT_READ8] =		{ 0x01, 0x43 },
46 	[CMD_TGT_READ32] =		{ 0x00, 0x5c },
47 	[CMD_TGT_READ32_LE] =		{ 0x01, 0x5c },
48 	[CMD_TGT_READ32_SWAP] =		{ 0x02, 0x5c },
49 	[CMD_TGT_READ_LE] =		{ 0x01, 0x40 },
50 	[CMD_TGT_READ_SWAP_LE] =	{ 0x03, 0x40 },
51 };
52 
53 static bool unreg_is_imm(u16 reg)
54 {
55 	return (reg & UR_REG_IMM) == UR_REG_IMM;
56 }
57 
58 u16 br_get_offset(u64 instr)
59 {
60 	u16 addr_lo, addr_hi;
61 
62 	addr_lo = FIELD_GET(OP_BR_ADDR_LO, instr);
63 	addr_hi = FIELD_GET(OP_BR_ADDR_HI, instr);
64 
65 	return (addr_hi * ((OP_BR_ADDR_LO >> __bf_shf(OP_BR_ADDR_LO)) + 1)) |
66 		addr_lo;
67 }
68 
69 void br_set_offset(u64 *instr, u16 offset)
70 {
71 	u16 addr_lo, addr_hi;
72 
73 	addr_lo = offset & (OP_BR_ADDR_LO >> __bf_shf(OP_BR_ADDR_LO));
74 	addr_hi = offset != addr_lo;
75 	*instr &= ~(OP_BR_ADDR_HI | OP_BR_ADDR_LO);
76 	*instr |= FIELD_PREP(OP_BR_ADDR_HI, addr_hi);
77 	*instr |= FIELD_PREP(OP_BR_ADDR_LO, addr_lo);
78 }
79 
80 void br_add_offset(u64 *instr, u16 offset)
81 {
82 	u16 addr;
83 
84 	addr = br_get_offset(*instr);
85 	br_set_offset(instr, addr + offset);
86 }
87 
88 static bool immed_can_modify(u64 instr)
89 {
90 	if (FIELD_GET(OP_IMMED_INV, instr) ||
91 	    FIELD_GET(OP_IMMED_SHIFT, instr) ||
92 	    FIELD_GET(OP_IMMED_WIDTH, instr) != IMMED_WIDTH_ALL) {
93 		pr_err("Can't decode/encode immed!\n");
94 		return false;
95 	}
96 	return true;
97 }
98 
99 u16 immed_get_value(u64 instr)
100 {
101 	u16 reg;
102 
103 	if (!immed_can_modify(instr))
104 		return 0;
105 
106 	reg = FIELD_GET(OP_IMMED_A_SRC, instr);
107 	if (!unreg_is_imm(reg))
108 		reg = FIELD_GET(OP_IMMED_B_SRC, instr);
109 
110 	return (reg & 0xff) | FIELD_GET(OP_IMMED_IMM, instr) << 8;
111 }
112 
113 void immed_set_value(u64 *instr, u16 immed)
114 {
115 	if (!immed_can_modify(*instr))
116 		return;
117 
118 	if (unreg_is_imm(FIELD_GET(OP_IMMED_A_SRC, *instr))) {
119 		*instr &= ~FIELD_PREP(OP_IMMED_A_SRC, 0xff);
120 		*instr |= FIELD_PREP(OP_IMMED_A_SRC, immed & 0xff);
121 	} else {
122 		*instr &= ~FIELD_PREP(OP_IMMED_B_SRC, 0xff);
123 		*instr |= FIELD_PREP(OP_IMMED_B_SRC, immed & 0xff);
124 	}
125 
126 	*instr &= ~OP_IMMED_IMM;
127 	*instr |= FIELD_PREP(OP_IMMED_IMM, immed >> 8);
128 }
129 
130 void immed_add_value(u64 *instr, u16 offset)
131 {
132 	u16 val;
133 
134 	if (!immed_can_modify(*instr))
135 		return;
136 
137 	val = immed_get_value(*instr);
138 	immed_set_value(instr, val + offset);
139 }
140 
141 static u16 nfp_swreg_to_unreg(swreg reg, bool is_dst)
142 {
143 	bool lm_id, lm_dec = false;
144 	u16 val = swreg_value(reg);
145 
146 	switch (swreg_type(reg)) {
147 	case NN_REG_GPR_A:
148 	case NN_REG_GPR_B:
149 	case NN_REG_GPR_BOTH:
150 		return val;
151 	case NN_REG_NNR:
152 		return UR_REG_NN | val;
153 	case NN_REG_XFER:
154 		return UR_REG_XFR | val;
155 	case NN_REG_LMEM:
156 		lm_id = swreg_lm_idx(reg);
157 
158 		switch (swreg_lm_mode(reg)) {
159 		case NN_LM_MOD_NONE:
160 			if (val & ~UR_REG_LM_IDX_MAX) {
161 				pr_err("LM offset too large\n");
162 				return 0;
163 			}
164 			return UR_REG_LM | FIELD_PREP(UR_REG_LM_IDX, lm_id) |
165 				val;
166 		case NN_LM_MOD_DEC:
167 			lm_dec = true;
168 			/* fall through */
169 		case NN_LM_MOD_INC:
170 			if (val) {
171 				pr_err("LM offset in inc/dev mode\n");
172 				return 0;
173 			}
174 			return UR_REG_LM | UR_REG_LM_POST_MOD |
175 				FIELD_PREP(UR_REG_LM_IDX, lm_id) |
176 				FIELD_PREP(UR_REG_LM_POST_MOD_DEC, lm_dec);
177 		default:
178 			pr_err("bad LM mode for unrestricted operands %d\n",
179 			       swreg_lm_mode(reg));
180 			return 0;
181 		}
182 	case NN_REG_IMM:
183 		if (val & ~0xff) {
184 			pr_err("immediate too large\n");
185 			return 0;
186 		}
187 		return UR_REG_IMM_encode(val);
188 	case NN_REG_NONE:
189 		return is_dst ? UR_REG_NO_DST : REG_NONE;
190 	}
191 
192 	pr_err("unrecognized reg encoding %08x\n", reg);
193 	return 0;
194 }
195 
196 int swreg_to_unrestricted(swreg dst, swreg lreg, swreg rreg,
197 			  struct nfp_insn_ur_regs *reg)
198 {
199 	memset(reg, 0, sizeof(*reg));
200 
201 	/* Decode destination */
202 	if (swreg_type(dst) == NN_REG_IMM)
203 		return -EFAULT;
204 
205 	if (swreg_type(dst) == NN_REG_GPR_B)
206 		reg->dst_ab = ALU_DST_B;
207 	if (swreg_type(dst) == NN_REG_GPR_BOTH)
208 		reg->wr_both = true;
209 	reg->dst = nfp_swreg_to_unreg(dst, true);
210 
211 	/* Decode source operands */
212 	if (swreg_type(lreg) == swreg_type(rreg) &&
213 	    swreg_type(lreg) != NN_REG_NONE)
214 		return -EFAULT;
215 
216 	if (swreg_type(lreg) == NN_REG_GPR_B ||
217 	    swreg_type(rreg) == NN_REG_GPR_A) {
218 		reg->areg = nfp_swreg_to_unreg(rreg, false);
219 		reg->breg = nfp_swreg_to_unreg(lreg, false);
220 		reg->swap = true;
221 	} else {
222 		reg->areg = nfp_swreg_to_unreg(lreg, false);
223 		reg->breg = nfp_swreg_to_unreg(rreg, false);
224 	}
225 
226 	reg->dst_lmextn = swreg_lmextn(dst);
227 	reg->src_lmextn = swreg_lmextn(lreg) | swreg_lmextn(rreg);
228 
229 	return 0;
230 }
231 
232 static u16 nfp_swreg_to_rereg(swreg reg, bool is_dst, bool has_imm8, bool *i8)
233 {
234 	u16 val = swreg_value(reg);
235 	bool lm_id;
236 
237 	switch (swreg_type(reg)) {
238 	case NN_REG_GPR_A:
239 	case NN_REG_GPR_B:
240 	case NN_REG_GPR_BOTH:
241 		return val;
242 	case NN_REG_XFER:
243 		return RE_REG_XFR | val;
244 	case NN_REG_LMEM:
245 		lm_id = swreg_lm_idx(reg);
246 
247 		if (swreg_lm_mode(reg) != NN_LM_MOD_NONE) {
248 			pr_err("bad LM mode for restricted operands %d\n",
249 			       swreg_lm_mode(reg));
250 			return 0;
251 		}
252 
253 		if (val & ~RE_REG_LM_IDX_MAX) {
254 			pr_err("LM offset too large\n");
255 			return 0;
256 		}
257 
258 		return RE_REG_LM | FIELD_PREP(RE_REG_LM_IDX, lm_id) | val;
259 	case NN_REG_IMM:
260 		if (val & ~(0x7f | has_imm8 << 7)) {
261 			pr_err("immediate too large\n");
262 			return 0;
263 		}
264 		*i8 = val & 0x80;
265 		return RE_REG_IMM_encode(val & 0x7f);
266 	case NN_REG_NONE:
267 		return is_dst ? RE_REG_NO_DST : REG_NONE;
268 	case NN_REG_NNR:
269 		pr_err("NNRs used with restricted encoding\n");
270 		return 0;
271 	}
272 
273 	pr_err("unrecognized reg encoding\n");
274 	return 0;
275 }
276 
277 int swreg_to_restricted(swreg dst, swreg lreg, swreg rreg,
278 			struct nfp_insn_re_regs *reg, bool has_imm8)
279 {
280 	memset(reg, 0, sizeof(*reg));
281 
282 	/* Decode destination */
283 	if (swreg_type(dst) == NN_REG_IMM)
284 		return -EFAULT;
285 
286 	if (swreg_type(dst) == NN_REG_GPR_B)
287 		reg->dst_ab = ALU_DST_B;
288 	if (swreg_type(dst) == NN_REG_GPR_BOTH)
289 		reg->wr_both = true;
290 	reg->dst = nfp_swreg_to_rereg(dst, true, false, NULL);
291 
292 	/* Decode source operands */
293 	if (swreg_type(lreg) == swreg_type(rreg) &&
294 	    swreg_type(lreg) != NN_REG_NONE)
295 		return -EFAULT;
296 
297 	if (swreg_type(lreg) == NN_REG_GPR_B ||
298 	    swreg_type(rreg) == NN_REG_GPR_A) {
299 		reg->areg = nfp_swreg_to_rereg(rreg, false, has_imm8, &reg->i8);
300 		reg->breg = nfp_swreg_to_rereg(lreg, false, has_imm8, &reg->i8);
301 		reg->swap = true;
302 	} else {
303 		reg->areg = nfp_swreg_to_rereg(lreg, false, has_imm8, &reg->i8);
304 		reg->breg = nfp_swreg_to_rereg(rreg, false, has_imm8, &reg->i8);
305 	}
306 
307 	reg->dst_lmextn = swreg_lmextn(dst);
308 	reg->src_lmextn = swreg_lmextn(lreg) | swreg_lmextn(rreg);
309 
310 	return 0;
311 }
312 
313 #define NFP_USTORE_ECC_POLY_WORDS		7
314 #define NFP_USTORE_OP_BITS			45
315 
316 static const u64 nfp_ustore_ecc_polynomials[NFP_USTORE_ECC_POLY_WORDS] = {
317 	0x0ff800007fffULL,
318 	0x11f801ff801fULL,
319 	0x1e387e0781e1ULL,
320 	0x17cb8e388e22ULL,
321 	0x1af5b2c93244ULL,
322 	0x1f56d5525488ULL,
323 	0x0daf69a46910ULL,
324 };
325 
326 static bool parity(u64 value)
327 {
328 	return hweight64(value) & 1;
329 }
330 
331 int nfp_ustore_check_valid_no_ecc(u64 insn)
332 {
333 	if (insn & ~GENMASK_ULL(NFP_USTORE_OP_BITS, 0))
334 		return -EINVAL;
335 
336 	return 0;
337 }
338 
339 u64 nfp_ustore_calc_ecc_insn(u64 insn)
340 {
341 	u8 ecc = 0;
342 	int i;
343 
344 	for (i = 0; i < NFP_USTORE_ECC_POLY_WORDS; i++)
345 		ecc |= parity(nfp_ustore_ecc_polynomials[i] & insn) << i;
346 
347 	return insn | (u64)ecc << NFP_USTORE_OP_BITS;
348 }
349