1 /*
2  * Copyright (c) 2012-2015,2017 Qualcomm Atheros, Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <linux/types.h>
18 #include <linux/errno.h>
19 #include <linux/fs.h>
20 #include "wmi.h"
21 #include "wil6210.h"
22 #include "txrx.h"
23 #include "pmc.h"
24 
25 struct desc_alloc_info {
26 	dma_addr_t pa;
27 	void	  *va;
28 };
29 
30 static int wil_is_pmc_allocated(struct pmc_ctx *pmc)
31 {
32 	return !!pmc->pring_va;
33 }
34 
35 void wil_pmc_init(struct wil6210_priv *wil)
36 {
37 	memset(&wil->pmc, 0, sizeof(struct pmc_ctx));
38 	mutex_init(&wil->pmc.lock);
39 }
40 
41 /**
42  * Allocate the physical ring (p-ring) and the required
43  * number of descriptors of required size.
44  * Initialize the descriptors as required by pmc dma.
45  * The descriptors' buffers dwords are initialized to hold
46  * dword's serial number in the lsw and reserved value
47  * PCM_DATA_INVALID_DW_VAL in the msw.
48  */
49 void wil_pmc_alloc(struct wil6210_priv *wil,
50 		   int num_descriptors,
51 		   int descriptor_size)
52 {
53 	u32 i;
54 	struct pmc_ctx *pmc = &wil->pmc;
55 	struct device *dev = wil_to_dev(wil);
56 	struct wmi_pmc_cmd pmc_cmd = {0};
57 	int last_cmd_err = -ENOMEM;
58 
59 	mutex_lock(&pmc->lock);
60 
61 	if (wil_is_pmc_allocated(pmc)) {
62 		/* sanity check */
63 		wil_err(wil, "ERROR pmc is already allocated\n");
64 		goto no_release_err;
65 	}
66 	if ((num_descriptors <= 0) || (descriptor_size <= 0)) {
67 		wil_err(wil,
68 			"Invalid params num_descriptors(%d), descriptor_size(%d)\n",
69 			num_descriptors, descriptor_size);
70 		last_cmd_err = -EINVAL;
71 		goto no_release_err;
72 	}
73 
74 	if (num_descriptors > (1 << WIL_RING_SIZE_ORDER_MAX)) {
75 		wil_err(wil,
76 			"num_descriptors(%d) exceeds max ring size %d\n",
77 			num_descriptors, 1 << WIL_RING_SIZE_ORDER_MAX);
78 		last_cmd_err = -EINVAL;
79 		goto no_release_err;
80 	}
81 
82 	if (num_descriptors > INT_MAX / descriptor_size) {
83 		wil_err(wil,
84 			"Overflow in num_descriptors(%d)*descriptor_size(%d)\n",
85 			num_descriptors, descriptor_size);
86 		last_cmd_err = -EINVAL;
87 		goto no_release_err;
88 	}
89 
90 	pmc->num_descriptors = num_descriptors;
91 	pmc->descriptor_size = descriptor_size;
92 
93 	wil_dbg_misc(wil, "pmc_alloc: %d descriptors x %d bytes each\n",
94 		     num_descriptors, descriptor_size);
95 
96 	/* allocate descriptors info list in pmc context*/
97 	pmc->descriptors = kcalloc(num_descriptors,
98 				  sizeof(struct desc_alloc_info),
99 				  GFP_KERNEL);
100 	if (!pmc->descriptors) {
101 		wil_err(wil, "ERROR allocating pmc skb list\n");
102 		goto no_release_err;
103 	}
104 
105 	wil_dbg_misc(wil, "pmc_alloc: allocated descriptors info list %p\n",
106 		     pmc->descriptors);
107 
108 	/* Allocate pring buffer and descriptors.
109 	 * vring->va should be aligned on its size rounded up to power of 2
110 	 * This is granted by the dma_alloc_coherent.
111 	 *
112 	 * HW has limitation that all vrings addresses must share the same
113 	 * upper 16 msb bits part of 48 bits address. To workaround that,
114 	 * if we are using more than 32 bit addresses switch to 32 bit
115 	 * allocation before allocating vring memory.
116 	 *
117 	 * There's no check for the return value of dma_set_mask_and_coherent,
118 	 * since we assume if we were able to set the mask during
119 	 * initialization in this system it will not fail if we set it again
120 	 */
121 	if (wil->dma_addr_size > 32)
122 		dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
123 
124 	pmc->pring_va = dma_alloc_coherent(dev,
125 			sizeof(struct vring_tx_desc) * num_descriptors,
126 			&pmc->pring_pa,
127 			GFP_KERNEL);
128 
129 	if (wil->dma_addr_size > 32)
130 		dma_set_mask_and_coherent(dev,
131 					  DMA_BIT_MASK(wil->dma_addr_size));
132 
133 	wil_dbg_misc(wil,
134 		     "pmc_alloc: allocated pring %p => %pad. %zd x %d = total %zd bytes\n",
135 		     pmc->pring_va, &pmc->pring_pa,
136 		     sizeof(struct vring_tx_desc),
137 		     num_descriptors,
138 		     sizeof(struct vring_tx_desc) * num_descriptors);
139 
140 	if (!pmc->pring_va) {
141 		wil_err(wil, "ERROR allocating pmc pring\n");
142 		goto release_pmc_skb_list;
143 	}
144 
145 	/* initially, all descriptors are SW owned
146 	 * For Tx, Rx, and PMC, ownership bit is at the same location, thus
147 	 * we can use any
148 	 */
149 	for (i = 0; i < num_descriptors; i++) {
150 		struct vring_tx_desc *_d = &pmc->pring_va[i];
151 		struct vring_tx_desc dd = {}, *d = &dd;
152 		int j = 0;
153 
154 		pmc->descriptors[i].va = dma_alloc_coherent(dev,
155 			descriptor_size,
156 			&pmc->descriptors[i].pa,
157 			GFP_KERNEL);
158 
159 		if (unlikely(!pmc->descriptors[i].va)) {
160 			wil_err(wil, "ERROR allocating pmc descriptor %d", i);
161 			goto release_pmc_skbs;
162 		}
163 
164 		for (j = 0; j < descriptor_size / sizeof(u32); j++) {
165 			u32 *p = (u32 *)pmc->descriptors[i].va + j;
166 			*p = PCM_DATA_INVALID_DW_VAL | j;
167 		}
168 
169 		/* configure dma descriptor */
170 		d->dma.addr.addr_low =
171 			cpu_to_le32(lower_32_bits(pmc->descriptors[i].pa));
172 		d->dma.addr.addr_high =
173 			cpu_to_le16((u16)upper_32_bits(pmc->descriptors[i].pa));
174 		d->dma.status = 0; /* 0 = HW_OWNED */
175 		d->dma.length = cpu_to_le16(descriptor_size);
176 		d->dma.d0 = BIT(9) | RX_DMA_D0_CMD_DMA_IT;
177 		*_d = *d;
178 	}
179 
180 	wil_dbg_misc(wil, "pmc_alloc: allocated successfully\n");
181 
182 	pmc_cmd.op = WMI_PMC_ALLOCATE;
183 	pmc_cmd.ring_size = cpu_to_le16(pmc->num_descriptors);
184 	pmc_cmd.mem_base = cpu_to_le64(pmc->pring_pa);
185 
186 	wil_dbg_misc(wil, "pmc_alloc: send WMI_PMC_CMD with ALLOCATE op\n");
187 	pmc->last_cmd_status = wmi_send(wil,
188 					WMI_PMC_CMDID,
189 					&pmc_cmd,
190 					sizeof(pmc_cmd));
191 	if (pmc->last_cmd_status) {
192 		wil_err(wil,
193 			"WMI_PMC_CMD with ALLOCATE op failed with status %d",
194 			pmc->last_cmd_status);
195 		goto release_pmc_skbs;
196 	}
197 
198 	mutex_unlock(&pmc->lock);
199 
200 	return;
201 
202 release_pmc_skbs:
203 	wil_err(wil, "exit on error: Releasing skbs...\n");
204 	for (i = 0; i < num_descriptors && pmc->descriptors[i].va; i++) {
205 		dma_free_coherent(dev,
206 				  descriptor_size,
207 				  pmc->descriptors[i].va,
208 				  pmc->descriptors[i].pa);
209 
210 		pmc->descriptors[i].va = NULL;
211 	}
212 	wil_err(wil, "exit on error: Releasing pring...\n");
213 
214 	dma_free_coherent(dev,
215 			  sizeof(struct vring_tx_desc) * num_descriptors,
216 			  pmc->pring_va,
217 			  pmc->pring_pa);
218 
219 	pmc->pring_va = NULL;
220 
221 release_pmc_skb_list:
222 	wil_err(wil, "exit on error: Releasing descriptors info list...\n");
223 	kfree(pmc->descriptors);
224 	pmc->descriptors = NULL;
225 
226 no_release_err:
227 	pmc->last_cmd_status = last_cmd_err;
228 	mutex_unlock(&pmc->lock);
229 }
230 
231 /**
232  * Traverse the p-ring and release all buffers.
233  * At the end release the p-ring memory
234  */
235 void wil_pmc_free(struct wil6210_priv *wil, int send_pmc_cmd)
236 {
237 	struct pmc_ctx *pmc = &wil->pmc;
238 	struct device *dev = wil_to_dev(wil);
239 	struct wmi_pmc_cmd pmc_cmd = {0};
240 
241 	mutex_lock(&pmc->lock);
242 
243 	pmc->last_cmd_status = 0;
244 
245 	if (!wil_is_pmc_allocated(pmc)) {
246 		wil_dbg_misc(wil,
247 			     "pmc_free: Error, can't free - not allocated\n");
248 		pmc->last_cmd_status = -EPERM;
249 		mutex_unlock(&pmc->lock);
250 		return;
251 	}
252 
253 	if (send_pmc_cmd) {
254 		wil_dbg_misc(wil, "send WMI_PMC_CMD with RELEASE op\n");
255 		pmc_cmd.op = WMI_PMC_RELEASE;
256 		pmc->last_cmd_status =
257 				wmi_send(wil, WMI_PMC_CMDID, &pmc_cmd,
258 					 sizeof(pmc_cmd));
259 		if (pmc->last_cmd_status) {
260 			wil_err(wil,
261 				"WMI_PMC_CMD with RELEASE op failed, status %d",
262 				pmc->last_cmd_status);
263 			/* There's nothing we can do with this error.
264 			 * Normally, it should never occur.
265 			 * Continue to freeing all memory allocated for pmc.
266 			 */
267 		}
268 	}
269 
270 	if (pmc->pring_va) {
271 		size_t buf_size = sizeof(struct vring_tx_desc) *
272 				  pmc->num_descriptors;
273 
274 		wil_dbg_misc(wil, "pmc_free: free pring va %p\n",
275 			     pmc->pring_va);
276 		dma_free_coherent(dev, buf_size, pmc->pring_va, pmc->pring_pa);
277 
278 		pmc->pring_va = NULL;
279 	} else {
280 		pmc->last_cmd_status = -ENOENT;
281 	}
282 
283 	if (pmc->descriptors) {
284 		int i;
285 
286 		for (i = 0;
287 		     i < pmc->num_descriptors && pmc->descriptors[i].va; i++) {
288 			dma_free_coherent(dev,
289 					  pmc->descriptor_size,
290 					  pmc->descriptors[i].va,
291 					  pmc->descriptors[i].pa);
292 			pmc->descriptors[i].va = NULL;
293 		}
294 		wil_dbg_misc(wil, "pmc_free: free descriptor info %d/%d\n", i,
295 			     pmc->num_descriptors);
296 		wil_dbg_misc(wil,
297 			     "pmc_free: free pmc descriptors info list %p\n",
298 			     pmc->descriptors);
299 		kfree(pmc->descriptors);
300 		pmc->descriptors = NULL;
301 	} else {
302 		pmc->last_cmd_status = -ENOENT;
303 	}
304 
305 	mutex_unlock(&pmc->lock);
306 }
307 
308 /**
309  * Status of the last operation requested via debugfs: alloc/free/read.
310  * 0 - success or negative errno
311  */
312 int wil_pmc_last_cmd_status(struct wil6210_priv *wil)
313 {
314 	wil_dbg_misc(wil, "pmc_last_cmd_status: status %d\n",
315 		     wil->pmc.last_cmd_status);
316 
317 	return wil->pmc.last_cmd_status;
318 }
319 
320 /**
321  * Read from required position up to the end of current descriptor,
322  * depends on descriptor size configured during alloc request.
323  */
324 ssize_t wil_pmc_read(struct file *filp, char __user *buf, size_t count,
325 		     loff_t *f_pos)
326 {
327 	struct wil6210_priv *wil = filp->private_data;
328 	struct pmc_ctx *pmc = &wil->pmc;
329 	size_t retval = 0;
330 	unsigned long long idx;
331 	loff_t offset;
332 	size_t pmc_size;
333 
334 	mutex_lock(&pmc->lock);
335 
336 	if (!wil_is_pmc_allocated(pmc)) {
337 		wil_err(wil, "error, pmc is not allocated!\n");
338 		pmc->last_cmd_status = -EPERM;
339 		mutex_unlock(&pmc->lock);
340 		return -EPERM;
341 	}
342 
343 	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
344 
345 	wil_dbg_misc(wil,
346 		     "pmc_read: size %u, pos %lld\n",
347 		     (u32)count, *f_pos);
348 
349 	pmc->last_cmd_status = 0;
350 
351 	idx = *f_pos;
352 	do_div(idx, pmc->descriptor_size);
353 	offset = *f_pos - (idx * pmc->descriptor_size);
354 
355 	if (*f_pos >= pmc_size) {
356 		wil_dbg_misc(wil,
357 			     "pmc_read: reached end of pmc buf: %lld >= %u\n",
358 			     *f_pos, (u32)pmc_size);
359 		pmc->last_cmd_status = -ERANGE;
360 		goto out;
361 	}
362 
363 	wil_dbg_misc(wil,
364 		     "pmc_read: read from pos %lld (descriptor %llu, offset %llu) %zu bytes\n",
365 		     *f_pos, idx, offset, count);
366 
367 	/* if no errors, return the copied byte count */
368 	retval = simple_read_from_buffer(buf,
369 					 count,
370 					 &offset,
371 					 pmc->descriptors[idx].va,
372 					 pmc->descriptor_size);
373 	*f_pos += retval;
374 out:
375 	mutex_unlock(&pmc->lock);
376 
377 	return retval;
378 }
379 
380 loff_t wil_pmc_llseek(struct file *filp, loff_t off, int whence)
381 {
382 	loff_t newpos;
383 	struct wil6210_priv *wil = filp->private_data;
384 	struct pmc_ctx *pmc = &wil->pmc;
385 	size_t pmc_size;
386 
387 	mutex_lock(&pmc->lock);
388 
389 	if (!wil_is_pmc_allocated(pmc)) {
390 		wil_err(wil, "error, pmc is not allocated!\n");
391 		pmc->last_cmd_status = -EPERM;
392 		mutex_unlock(&pmc->lock);
393 		return -EPERM;
394 	}
395 
396 	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
397 
398 	switch (whence) {
399 	case 0: /* SEEK_SET */
400 		newpos = off;
401 		break;
402 
403 	case 1: /* SEEK_CUR */
404 		newpos = filp->f_pos + off;
405 		break;
406 
407 	case 2: /* SEEK_END */
408 		newpos = pmc_size;
409 		break;
410 
411 	default: /* can't happen */
412 		newpos = -EINVAL;
413 		goto out;
414 	}
415 
416 	if (newpos < 0) {
417 		newpos = -EINVAL;
418 		goto out;
419 	}
420 	if (newpos > pmc_size)
421 		newpos = pmc_size;
422 
423 	filp->f_pos = newpos;
424 
425 out:
426 	mutex_unlock(&pmc->lock);
427 
428 	return newpos;
429 }
430