1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Driver for the NXP SAA7164 PCIe bridge |
4 | * |
5 | * Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com> |
6 | */ |
7 | |
8 | #include "saa7164.h" |
9 | |
10 | /* The message bus to/from the firmware is a ring buffer in PCI address |
11 | * space. Establish the defaults. |
12 | */ |
13 | int saa7164_bus_setup(struct saa7164_dev *dev) |
14 | { |
15 | struct tmComResBusInfo *b = &dev->bus; |
16 | |
17 | mutex_init(&b->lock); |
18 | |
19 | b->Type = TYPE_BUS_PCIe; |
20 | b->m_wMaxReqSize = SAA_DEVICE_MAXREQUESTSIZE; |
21 | |
22 | b->m_pdwSetRing = (u8 __iomem *)(dev->bmmio + |
23 | ((u32)dev->busdesc.CommandRing)); |
24 | |
25 | b->m_dwSizeSetRing = SAA_DEVICE_BUFFERBLOCKSIZE; |
26 | |
27 | b->m_pdwGetRing = (u8 __iomem *)(dev->bmmio + |
28 | ((u32)dev->busdesc.ResponseRing)); |
29 | |
30 | b->m_dwSizeGetRing = SAA_DEVICE_BUFFERBLOCKSIZE; |
31 | |
32 | b->m_dwSetWritePos = ((u32)dev->intfdesc.BARLocation) + |
33 | (2 * sizeof(u64)); |
34 | b->m_dwSetReadPos = b->m_dwSetWritePos + (1 * sizeof(u32)); |
35 | |
36 | b->m_dwGetWritePos = b->m_dwSetWritePos + (2 * sizeof(u32)); |
37 | b->m_dwGetReadPos = b->m_dwSetWritePos + (3 * sizeof(u32)); |
38 | |
39 | return 0; |
40 | } |
41 | |
42 | void saa7164_bus_dump(struct saa7164_dev *dev) |
43 | { |
44 | struct tmComResBusInfo *b = &dev->bus; |
45 | |
46 | dprintk(DBGLVL_BUS, "Dumping the bus structure:\n" ); |
47 | dprintk(DBGLVL_BUS, " .type = %d\n" , b->Type); |
48 | dprintk(DBGLVL_BUS, " .dev->bmmio = 0x%p\n" , dev->bmmio); |
49 | dprintk(DBGLVL_BUS, " .m_wMaxReqSize = 0x%x\n" , b->m_wMaxReqSize); |
50 | dprintk(DBGLVL_BUS, " .m_pdwSetRing = 0x%p\n" , b->m_pdwSetRing); |
51 | dprintk(DBGLVL_BUS, " .m_dwSizeSetRing = 0x%x\n" , b->m_dwSizeSetRing); |
52 | dprintk(DBGLVL_BUS, " .m_pdwGetRing = 0x%p\n" , b->m_pdwGetRing); |
53 | dprintk(DBGLVL_BUS, " .m_dwSizeGetRing = 0x%x\n" , b->m_dwSizeGetRing); |
54 | |
55 | dprintk(DBGLVL_BUS, " .m_dwSetReadPos = 0x%x (0x%08x)\n" , |
56 | b->m_dwSetReadPos, saa7164_readl(b->m_dwSetReadPos)); |
57 | |
58 | dprintk(DBGLVL_BUS, " .m_dwSetWritePos = 0x%x (0x%08x)\n" , |
59 | b->m_dwSetWritePos, saa7164_readl(b->m_dwSetWritePos)); |
60 | |
61 | dprintk(DBGLVL_BUS, " .m_dwGetReadPos = 0x%x (0x%08x)\n" , |
62 | b->m_dwGetReadPos, saa7164_readl(b->m_dwGetReadPos)); |
63 | |
64 | dprintk(DBGLVL_BUS, " .m_dwGetWritePos = 0x%x (0x%08x)\n" , |
65 | b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos)); |
66 | |
67 | } |
68 | |
69 | /* Intensionally throw a BUG() if the state of the message bus looks corrupt */ |
70 | static void saa7164_bus_verify(struct saa7164_dev *dev) |
71 | { |
72 | struct tmComResBusInfo *b = &dev->bus; |
73 | int bug = 0; |
74 | |
75 | if (saa7164_readl(b->m_dwSetReadPos) > b->m_dwSizeSetRing) |
76 | bug++; |
77 | |
78 | if (saa7164_readl(b->m_dwSetWritePos) > b->m_dwSizeSetRing) |
79 | bug++; |
80 | |
81 | if (saa7164_readl(b->m_dwGetReadPos) > b->m_dwSizeGetRing) |
82 | bug++; |
83 | |
84 | if (saa7164_readl(b->m_dwGetWritePos) > b->m_dwSizeGetRing) |
85 | bug++; |
86 | |
87 | if (bug) { |
88 | saa_debug = 0xffff; /* Ensure we get the bus dump */ |
89 | saa7164_bus_dump(dev); |
90 | saa_debug = 1024; /* Ensure we get the bus dump */ |
91 | BUG(); |
92 | } |
93 | } |
94 | |
95 | static void saa7164_bus_dumpmsg(struct saa7164_dev *dev, struct tmComResInfo *m, |
96 | void *buf) |
97 | { |
98 | dprintk(DBGLVL_BUS, "Dumping msg structure:\n" ); |
99 | dprintk(DBGLVL_BUS, " .id = %d\n" , m->id); |
100 | dprintk(DBGLVL_BUS, " .flags = 0x%x\n" , m->flags); |
101 | dprintk(DBGLVL_BUS, " .size = 0x%x\n" , m->size); |
102 | dprintk(DBGLVL_BUS, " .command = 0x%x\n" , m->command); |
103 | dprintk(DBGLVL_BUS, " .controlselector = 0x%x\n" , m->controlselector); |
104 | dprintk(DBGLVL_BUS, " .seqno = %d\n" , m->seqno); |
105 | if (buf) |
106 | dprintk(DBGLVL_BUS, " .buffer (ignored)\n" ); |
107 | } |
108 | |
109 | /* |
110 | * Places a command or a response on the bus. The implementation does not |
111 | * know if it is a command or a response it just places the data on the |
112 | * bus depending on the bus information given in the struct tmComResBusInfo |
113 | * structure. If the command or response does not fit into the bus ring |
114 | * buffer it will be refused. |
115 | * |
116 | * Return Value: |
117 | * SAA_OK The function executed successfully. |
118 | * < 0 One or more members are not initialized. |
119 | */ |
120 | int saa7164_bus_set(struct saa7164_dev *dev, struct tmComResInfo* msg, |
121 | void *buf) |
122 | { |
123 | struct tmComResBusInfo *bus = &dev->bus; |
124 | u32 bytes_to_write, free_write_space, timeout, curr_srp, curr_swp; |
125 | u32 new_swp, space_rem; |
126 | int ret = SAA_ERR_BAD_PARAMETER; |
127 | u16 size; |
128 | |
129 | if (!msg) { |
130 | printk(KERN_ERR "%s() !msg\n" , __func__); |
131 | return SAA_ERR_BAD_PARAMETER; |
132 | } |
133 | |
134 | dprintk(DBGLVL_BUS, "%s()\n" , __func__); |
135 | |
136 | saa7164_bus_verify(dev); |
137 | |
138 | if (msg->size > dev->bus.m_wMaxReqSize) { |
139 | printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n" , |
140 | __func__); |
141 | return SAA_ERR_BAD_PARAMETER; |
142 | } |
143 | |
144 | if ((msg->size > 0) && (buf == NULL)) { |
145 | printk(KERN_ERR "%s() Missing message buffer\n" , __func__); |
146 | return SAA_ERR_BAD_PARAMETER; |
147 | } |
148 | |
149 | /* Lock the bus from any other access */ |
150 | mutex_lock(&bus->lock); |
151 | |
152 | bytes_to_write = sizeof(*msg) + msg->size; |
153 | free_write_space = 0; |
154 | timeout = SAA_BUS_TIMEOUT; |
155 | curr_srp = saa7164_readl(bus->m_dwSetReadPos); |
156 | curr_swp = saa7164_readl(bus->m_dwSetWritePos); |
157 | |
158 | /* Deal with ring wrapping issues */ |
159 | if (curr_srp > curr_swp) |
160 | /* Deal with the wrapped ring */ |
161 | free_write_space = curr_srp - curr_swp; |
162 | else |
163 | /* The ring has not wrapped yet */ |
164 | free_write_space = (curr_srp + bus->m_dwSizeSetRing) - curr_swp; |
165 | |
166 | dprintk(DBGLVL_BUS, "%s() bytes_to_write = %d\n" , __func__, |
167 | bytes_to_write); |
168 | |
169 | dprintk(DBGLVL_BUS, "%s() free_write_space = %d\n" , __func__, |
170 | free_write_space); |
171 | |
172 | dprintk(DBGLVL_BUS, "%s() curr_srp = %x\n" , __func__, curr_srp); |
173 | dprintk(DBGLVL_BUS, "%s() curr_swp = %x\n" , __func__, curr_swp); |
174 | |
175 | /* Process the msg and write the content onto the bus */ |
176 | while (bytes_to_write >= free_write_space) { |
177 | |
178 | if (timeout-- == 0) { |
179 | printk(KERN_ERR "%s() bus timeout\n" , __func__); |
180 | ret = SAA_ERR_NO_RESOURCES; |
181 | goto out; |
182 | } |
183 | |
184 | /* TODO: Review this delay, efficient? */ |
185 | /* Wait, allowing the hardware fetch time */ |
186 | mdelay(1); |
187 | |
188 | /* Check the space usage again */ |
189 | curr_srp = saa7164_readl(bus->m_dwSetReadPos); |
190 | |
191 | /* Deal with ring wrapping issues */ |
192 | if (curr_srp > curr_swp) |
193 | /* Deal with the wrapped ring */ |
194 | free_write_space = curr_srp - curr_swp; |
195 | else |
196 | /* Read didn't wrap around the buffer */ |
197 | free_write_space = (curr_srp + bus->m_dwSizeSetRing) - |
198 | curr_swp; |
199 | |
200 | } |
201 | |
202 | /* Calculate the new write position */ |
203 | new_swp = curr_swp + bytes_to_write; |
204 | |
205 | dprintk(DBGLVL_BUS, "%s() new_swp = %x\n" , __func__, new_swp); |
206 | dprintk(DBGLVL_BUS, "%s() bus->m_dwSizeSetRing = %x\n" , __func__, |
207 | bus->m_dwSizeSetRing); |
208 | |
209 | /* |
210 | * Make a copy of msg->size before it is converted to le16 since it is |
211 | * used in the code below. |
212 | */ |
213 | size = msg->size; |
214 | /* Convert to le16/le32 */ |
215 | msg->size = (__force u16)cpu_to_le16(msg->size); |
216 | msg->command = (__force u32)cpu_to_le32(msg->command); |
217 | msg->controlselector = (__force u16)cpu_to_le16(msg->controlselector); |
218 | |
219 | /* Mental Note: line 462 tmmhComResBusPCIe.cpp */ |
220 | |
221 | /* Check if we're going to wrap again */ |
222 | if (new_swp > bus->m_dwSizeSetRing) { |
223 | |
224 | /* Ring wraps */ |
225 | new_swp -= bus->m_dwSizeSetRing; |
226 | |
227 | space_rem = bus->m_dwSizeSetRing - curr_swp; |
228 | |
229 | dprintk(DBGLVL_BUS, "%s() space_rem = %x\n" , __func__, |
230 | space_rem); |
231 | |
232 | dprintk(DBGLVL_BUS, "%s() sizeof(*msg) = %d\n" , __func__, |
233 | (u32)sizeof(*msg)); |
234 | |
235 | if (space_rem < sizeof(*msg)) { |
236 | dprintk(DBGLVL_BUS, "%s() tr4\n" , __func__); |
237 | |
238 | /* Split the msg into pieces as the ring wraps */ |
239 | memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, space_rem); |
240 | memcpy_toio(bus->m_pdwSetRing, (u8 *)msg + space_rem, |
241 | sizeof(*msg) - space_rem); |
242 | |
243 | memcpy_toio(bus->m_pdwSetRing + sizeof(*msg) - space_rem, |
244 | buf, size); |
245 | |
246 | } else if (space_rem == sizeof(*msg)) { |
247 | dprintk(DBGLVL_BUS, "%s() tr5\n" , __func__); |
248 | |
249 | /* Additional data at the beginning of the ring */ |
250 | memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg)); |
251 | memcpy_toio(bus->m_pdwSetRing, buf, size); |
252 | |
253 | } else { |
254 | /* Additional data wraps around the ring */ |
255 | memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg)); |
256 | if (size > 0) { |
257 | memcpy_toio(bus->m_pdwSetRing + curr_swp + |
258 | sizeof(*msg), buf, space_rem - |
259 | sizeof(*msg)); |
260 | memcpy_toio(bus->m_pdwSetRing, (u8 *)buf + |
261 | space_rem - sizeof(*msg), |
262 | bytes_to_write - space_rem); |
263 | } |
264 | |
265 | } |
266 | |
267 | } /* (new_swp > bus->m_dwSizeSetRing) */ |
268 | else { |
269 | dprintk(DBGLVL_BUS, "%s() tr6\n" , __func__); |
270 | |
271 | /* The ring buffer doesn't wrap, two simple copies */ |
272 | memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg)); |
273 | memcpy_toio(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf, |
274 | size); |
275 | } |
276 | |
277 | dprintk(DBGLVL_BUS, "%s() new_swp = %x\n" , __func__, new_swp); |
278 | |
279 | /* Update the bus write position */ |
280 | saa7164_writel(bus->m_dwSetWritePos, new_swp); |
281 | |
282 | /* Convert back to cpu after writing the msg to the ringbuffer. */ |
283 | msg->size = le16_to_cpu((__force __le16)msg->size); |
284 | msg->command = le32_to_cpu((__force __le32)msg->command); |
285 | msg->controlselector = le16_to_cpu((__force __le16)msg->controlselector); |
286 | ret = SAA_OK; |
287 | |
288 | out: |
289 | saa7164_bus_dump(dev); |
290 | mutex_unlock(lock: &bus->lock); |
291 | saa7164_bus_verify(dev); |
292 | return ret; |
293 | } |
294 | |
295 | /* |
296 | * Receive a command or a response from the bus. The implementation does not |
297 | * know if it is a command or a response it simply dequeues the data, |
298 | * depending on the bus information given in the struct tmComResBusInfo |
299 | * structure. |
300 | * |
301 | * Return Value: |
302 | * 0 The function executed successfully. |
303 | * < 0 One or more members are not initialized. |
304 | */ |
305 | int saa7164_bus_get(struct saa7164_dev *dev, struct tmComResInfo* msg, |
306 | void *buf, int peekonly) |
307 | { |
308 | struct tmComResBusInfo *bus = &dev->bus; |
309 | u32 bytes_to_read, write_distance, curr_grp, curr_gwp, |
310 | new_grp, buf_size, space_rem; |
311 | struct tmComResInfo msg_tmp; |
312 | int ret = SAA_ERR_BAD_PARAMETER; |
313 | |
314 | saa7164_bus_verify(dev); |
315 | |
316 | if (msg == NULL) |
317 | return ret; |
318 | |
319 | if (msg->size > dev->bus.m_wMaxReqSize) { |
320 | printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n" , |
321 | __func__); |
322 | return ret; |
323 | } |
324 | |
325 | if ((peekonly == 0) && (msg->size > 0) && (buf == NULL)) { |
326 | printk(KERN_ERR |
327 | "%s() Missing msg buf, size should be %d bytes\n" , |
328 | __func__, msg->size); |
329 | return ret; |
330 | } |
331 | |
332 | mutex_lock(&bus->lock); |
333 | |
334 | /* Peek the bus to see if a msg exists, if it's not what we're expecting |
335 | * then return cleanly else read the message from the bus. |
336 | */ |
337 | curr_gwp = saa7164_readl(bus->m_dwGetWritePos); |
338 | curr_grp = saa7164_readl(bus->m_dwGetReadPos); |
339 | |
340 | if (curr_gwp == curr_grp) { |
341 | ret = SAA_ERR_EMPTY; |
342 | goto out; |
343 | } |
344 | |
345 | bytes_to_read = sizeof(*msg); |
346 | |
347 | /* Calculate write distance to current read position */ |
348 | write_distance = 0; |
349 | if (curr_gwp >= curr_grp) |
350 | /* Write doesn't wrap around the ring */ |
351 | write_distance = curr_gwp - curr_grp; |
352 | else |
353 | /* Write wraps around the ring */ |
354 | write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp; |
355 | |
356 | if (bytes_to_read > write_distance) { |
357 | printk(KERN_ERR "%s() No message/response found\n" , __func__); |
358 | ret = SAA_ERR_INVALID_COMMAND; |
359 | goto out; |
360 | } |
361 | |
362 | /* Calculate the new read position */ |
363 | new_grp = curr_grp + bytes_to_read; |
364 | if (new_grp > bus->m_dwSizeGetRing) { |
365 | |
366 | /* Ring wraps */ |
367 | new_grp -= bus->m_dwSizeGetRing; |
368 | space_rem = bus->m_dwSizeGetRing - curr_grp; |
369 | |
370 | memcpy_fromio(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem); |
371 | memcpy_fromio((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing, |
372 | bytes_to_read - space_rem); |
373 | |
374 | } else { |
375 | /* No wrapping */ |
376 | memcpy_fromio(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read); |
377 | } |
378 | /* Convert from little endian to CPU */ |
379 | msg_tmp.size = le16_to_cpu((__force __le16)msg_tmp.size); |
380 | msg_tmp.command = le32_to_cpu((__force __le32)msg_tmp.command); |
381 | msg_tmp.controlselector = le16_to_cpu((__force __le16)msg_tmp.controlselector); |
382 | memcpy(msg, &msg_tmp, sizeof(*msg)); |
383 | |
384 | /* No need to update the read positions, because this was a peek */ |
385 | /* If the caller specifically want to peek, return */ |
386 | if (peekonly) { |
387 | goto peekout; |
388 | } |
389 | |
390 | /* Check if the command/response matches what is expected */ |
391 | if ((msg_tmp.id != msg->id) || (msg_tmp.command != msg->command) || |
392 | (msg_tmp.controlselector != msg->controlselector) || |
393 | (msg_tmp.seqno != msg->seqno) || (msg_tmp.size != msg->size)) { |
394 | |
395 | printk(KERN_ERR "%s() Unexpected msg miss-match\n" , __func__); |
396 | saa7164_bus_dumpmsg(dev, m: msg, buf); |
397 | saa7164_bus_dumpmsg(dev, m: &msg_tmp, NULL); |
398 | ret = SAA_ERR_INVALID_COMMAND; |
399 | goto out; |
400 | } |
401 | |
402 | /* Get the actual command and response from the bus */ |
403 | buf_size = msg->size; |
404 | |
405 | bytes_to_read = sizeof(*msg) + msg->size; |
406 | /* Calculate write distance to current read position */ |
407 | write_distance = 0; |
408 | if (curr_gwp >= curr_grp) |
409 | /* Write doesn't wrap around the ring */ |
410 | write_distance = curr_gwp - curr_grp; |
411 | else |
412 | /* Write wraps around the ring */ |
413 | write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp; |
414 | |
415 | if (bytes_to_read > write_distance) { |
416 | printk(KERN_ERR "%s() Invalid bus state, missing msg or mangled ring, faulty H/W / bad code?\n" , |
417 | __func__); |
418 | ret = SAA_ERR_INVALID_COMMAND; |
419 | goto out; |
420 | } |
421 | |
422 | /* Calculate the new read position */ |
423 | new_grp = curr_grp + bytes_to_read; |
424 | if (new_grp > bus->m_dwSizeGetRing) { |
425 | |
426 | /* Ring wraps */ |
427 | new_grp -= bus->m_dwSizeGetRing; |
428 | space_rem = bus->m_dwSizeGetRing - curr_grp; |
429 | |
430 | if (space_rem < sizeof(*msg)) { |
431 | if (buf) |
432 | memcpy_fromio(buf, bus->m_pdwGetRing + sizeof(*msg) - |
433 | space_rem, buf_size); |
434 | |
435 | } else if (space_rem == sizeof(*msg)) { |
436 | if (buf) |
437 | memcpy_fromio(buf, bus->m_pdwGetRing, buf_size); |
438 | } else { |
439 | /* Additional data wraps around the ring */ |
440 | if (buf) { |
441 | memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp + |
442 | sizeof(*msg), space_rem - sizeof(*msg)); |
443 | memcpy_fromio(buf + space_rem - sizeof(*msg), |
444 | bus->m_pdwGetRing, bytes_to_read - |
445 | space_rem); |
446 | } |
447 | |
448 | } |
449 | |
450 | } else { |
451 | /* No wrapping */ |
452 | if (buf) |
453 | memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg), |
454 | buf_size); |
455 | } |
456 | |
457 | /* Update the read positions, adjusting the ring */ |
458 | saa7164_writel(bus->m_dwGetReadPos, new_grp); |
459 | |
460 | peekout: |
461 | ret = SAA_OK; |
462 | out: |
463 | mutex_unlock(lock: &bus->lock); |
464 | saa7164_bus_verify(dev); |
465 | return ret; |
466 | } |
467 | |
468 | |