xref: /linux/drivers/net/wireless/ath/wil6210/pmc.c (revision 32786fdc9506aeba98278c1844d4bfb766863832)
1 /*
2  * Copyright (c) 2012-2015 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, "%s: ERROR pmc is already allocated\n", __func__);
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, "%s: %d descriptors x %d bytes each\n",
94 		     __func__, 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, "%s: ERROR allocating pmc skb list\n", __func__);
102 		goto no_release_err;
103 	}
104 
105 	wil_dbg_misc(wil,
106 		     "%s: allocated descriptors info list %p\n",
107 		     __func__, pmc->descriptors);
108 
109 	/* Allocate pring buffer and descriptors.
110 	 * vring->va should be aligned on its size rounded up to power of 2
111 	 * This is granted by the dma_alloc_coherent
112 	 */
113 	pmc->pring_va = dma_alloc_coherent(dev,
114 			sizeof(struct vring_tx_desc) * num_descriptors,
115 			&pmc->pring_pa,
116 			GFP_KERNEL);
117 
118 	wil_dbg_misc(wil,
119 		     "%s: allocated pring %p => %pad. %zd x %d = total %zd bytes\n",
120 		     __func__,
121 		     pmc->pring_va, &pmc->pring_pa,
122 		     sizeof(struct vring_tx_desc),
123 		     num_descriptors,
124 		     sizeof(struct vring_tx_desc) * num_descriptors);
125 
126 	if (!pmc->pring_va) {
127 		wil_err(wil, "%s: ERROR allocating pmc pring\n", __func__);
128 		goto release_pmc_skb_list;
129 	}
130 
131 	/* initially, all descriptors are SW owned
132 	 * For Tx, Rx, and PMC, ownership bit is at the same location, thus
133 	 * we can use any
134 	 */
135 	for (i = 0; i < num_descriptors; i++) {
136 		struct vring_tx_desc *_d = &pmc->pring_va[i];
137 		struct vring_tx_desc dd = {}, *d = &dd;
138 		int j = 0;
139 
140 		pmc->descriptors[i].va = dma_alloc_coherent(dev,
141 			descriptor_size,
142 			&pmc->descriptors[i].pa,
143 			GFP_KERNEL);
144 
145 		if (unlikely(!pmc->descriptors[i].va)) {
146 			wil_err(wil,
147 				"%s: ERROR allocating pmc descriptor %d",
148 				__func__, i);
149 			goto release_pmc_skbs;
150 		}
151 
152 		for (j = 0; j < descriptor_size / sizeof(u32); j++) {
153 			u32 *p = (u32 *)pmc->descriptors[i].va + j;
154 			*p = PCM_DATA_INVALID_DW_VAL | j;
155 		}
156 
157 		/* configure dma descriptor */
158 		d->dma.addr.addr_low =
159 			cpu_to_le32(lower_32_bits(pmc->descriptors[i].pa));
160 		d->dma.addr.addr_high =
161 			cpu_to_le16((u16)upper_32_bits(pmc->descriptors[i].pa));
162 		d->dma.status = 0; /* 0 = HW_OWNED */
163 		d->dma.length = cpu_to_le16(descriptor_size);
164 		d->dma.d0 = BIT(9) | RX_DMA_D0_CMD_DMA_IT;
165 		*_d = *d;
166 	}
167 
168 	wil_dbg_misc(wil, "%s: allocated successfully\n", __func__);
169 
170 	pmc_cmd.op = WMI_PMC_ALLOCATE;
171 	pmc_cmd.ring_size = cpu_to_le16(pmc->num_descriptors);
172 	pmc_cmd.mem_base = cpu_to_le64(pmc->pring_pa);
173 
174 	wil_dbg_misc(wil, "%s: send WMI_PMC_CMD with ALLOCATE op\n", __func__);
175 	pmc->last_cmd_status = wmi_send(wil,
176 					WMI_PMC_CMDID,
177 					&pmc_cmd,
178 					sizeof(pmc_cmd));
179 	if (pmc->last_cmd_status) {
180 		wil_err(wil,
181 			"%s: WMI_PMC_CMD with ALLOCATE op failed with status %d",
182 			__func__, pmc->last_cmd_status);
183 		goto release_pmc_skbs;
184 	}
185 
186 	mutex_unlock(&pmc->lock);
187 
188 	return;
189 
190 release_pmc_skbs:
191 	wil_err(wil, "%s: exit on error: Releasing skbs...\n", __func__);
192 	for (i = 0; pmc->descriptors[i].va && i < num_descriptors; i++) {
193 		dma_free_coherent(dev,
194 				  descriptor_size,
195 				  pmc->descriptors[i].va,
196 				  pmc->descriptors[i].pa);
197 
198 		pmc->descriptors[i].va = NULL;
199 	}
200 	wil_err(wil, "%s: exit on error: Releasing pring...\n", __func__);
201 
202 	dma_free_coherent(dev,
203 			  sizeof(struct vring_tx_desc) * num_descriptors,
204 			  pmc->pring_va,
205 			  pmc->pring_pa);
206 
207 	pmc->pring_va = NULL;
208 
209 release_pmc_skb_list:
210 	wil_err(wil, "%s: exit on error: Releasing descriptors info list...\n",
211 		__func__);
212 	kfree(pmc->descriptors);
213 	pmc->descriptors = NULL;
214 
215 no_release_err:
216 	pmc->last_cmd_status = last_cmd_err;
217 	mutex_unlock(&pmc->lock);
218 }
219 
220 /**
221  * Traverse the p-ring and release all buffers.
222  * At the end release the p-ring memory
223  */
224 void wil_pmc_free(struct wil6210_priv *wil, int send_pmc_cmd)
225 {
226 	struct pmc_ctx *pmc = &wil->pmc;
227 	struct device *dev = wil_to_dev(wil);
228 	struct wmi_pmc_cmd pmc_cmd = {0};
229 
230 	mutex_lock(&pmc->lock);
231 
232 	pmc->last_cmd_status = 0;
233 
234 	if (!wil_is_pmc_allocated(pmc)) {
235 		wil_dbg_misc(wil, "%s: Error, can't free - not allocated\n",
236 			     __func__);
237 		pmc->last_cmd_status = -EPERM;
238 		mutex_unlock(&pmc->lock);
239 		return;
240 	}
241 
242 	if (send_pmc_cmd) {
243 		wil_dbg_misc(wil, "%s: send WMI_PMC_CMD with RELEASE op\n",
244 			     __func__);
245 		pmc_cmd.op = WMI_PMC_RELEASE;
246 		pmc->last_cmd_status =
247 				wmi_send(wil, WMI_PMC_CMDID, &pmc_cmd,
248 					 sizeof(pmc_cmd));
249 		if (pmc->last_cmd_status) {
250 			wil_err(wil,
251 				"%s WMI_PMC_CMD with RELEASE op failed, status %d",
252 				__func__, pmc->last_cmd_status);
253 			/* There's nothing we can do with this error.
254 			 * Normally, it should never occur.
255 			 * Continue to freeing all memory allocated for pmc.
256 			 */
257 		}
258 	}
259 
260 	if (pmc->pring_va) {
261 		size_t buf_size = sizeof(struct vring_tx_desc) *
262 				  pmc->num_descriptors;
263 
264 		wil_dbg_misc(wil, "%s: free pring va %p\n",
265 			     __func__, pmc->pring_va);
266 		dma_free_coherent(dev, buf_size, pmc->pring_va, pmc->pring_pa);
267 
268 		pmc->pring_va = NULL;
269 	} else {
270 		pmc->last_cmd_status = -ENOENT;
271 	}
272 
273 	if (pmc->descriptors) {
274 		int i;
275 
276 		for (i = 0;
277 		     pmc->descriptors[i].va && i < pmc->num_descriptors; i++) {
278 			dma_free_coherent(dev,
279 					  pmc->descriptor_size,
280 					  pmc->descriptors[i].va,
281 					  pmc->descriptors[i].pa);
282 			pmc->descriptors[i].va = NULL;
283 		}
284 		wil_dbg_misc(wil, "%s: free descriptor info %d/%d\n",
285 			     __func__, i, pmc->num_descriptors);
286 		wil_dbg_misc(wil,
287 			     "%s: free pmc descriptors info list %p\n",
288 			     __func__, pmc->descriptors);
289 		kfree(pmc->descriptors);
290 		pmc->descriptors = NULL;
291 	} else {
292 		pmc->last_cmd_status = -ENOENT;
293 	}
294 
295 	mutex_unlock(&pmc->lock);
296 }
297 
298 /**
299  * Status of the last operation requested via debugfs: alloc/free/read.
300  * 0 - success or negative errno
301  */
302 int wil_pmc_last_cmd_status(struct wil6210_priv *wil)
303 {
304 	wil_dbg_misc(wil, "%s: status %d\n", __func__,
305 		     wil->pmc.last_cmd_status);
306 
307 	return wil->pmc.last_cmd_status;
308 }
309 
310 /**
311  * Read from required position up to the end of current descriptor,
312  * depends on descriptor size configured during alloc request.
313  */
314 ssize_t wil_pmc_read(struct file *filp, char __user *buf, size_t count,
315 		     loff_t *f_pos)
316 {
317 	struct wil6210_priv *wil = filp->private_data;
318 	struct pmc_ctx *pmc = &wil->pmc;
319 	size_t retval = 0;
320 	unsigned long long idx;
321 	loff_t offset;
322 	size_t pmc_size;
323 
324 	mutex_lock(&pmc->lock);
325 
326 	if (!wil_is_pmc_allocated(pmc)) {
327 		wil_err(wil, "%s: error, pmc is not allocated!\n", __func__);
328 		pmc->last_cmd_status = -EPERM;
329 		mutex_unlock(&pmc->lock);
330 		return -EPERM;
331 	}
332 
333 	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
334 
335 	wil_dbg_misc(wil,
336 		     "%s: size %u, pos %lld\n",
337 		     __func__, (unsigned)count, *f_pos);
338 
339 	pmc->last_cmd_status = 0;
340 
341 	idx = *f_pos;
342 	do_div(idx, pmc->descriptor_size);
343 	offset = *f_pos - (idx * pmc->descriptor_size);
344 
345 	if (*f_pos >= pmc_size) {
346 		wil_dbg_misc(wil, "%s: reached end of pmc buf: %lld >= %u\n",
347 			     __func__, *f_pos, (unsigned)pmc_size);
348 		pmc->last_cmd_status = -ERANGE;
349 		goto out;
350 	}
351 
352 	wil_dbg_misc(wil,
353 		     "%s: read from pos %lld (descriptor %llu, offset %llu) %zu bytes\n",
354 		     __func__, *f_pos, idx, offset, count);
355 
356 	/* if no errors, return the copied byte count */
357 	retval = simple_read_from_buffer(buf,
358 					 count,
359 					 &offset,
360 					 pmc->descriptors[idx].va,
361 					 pmc->descriptor_size);
362 	*f_pos += retval;
363 out:
364 	mutex_unlock(&pmc->lock);
365 
366 	return retval;
367 }
368 
369 loff_t wil_pmc_llseek(struct file *filp, loff_t off, int whence)
370 {
371 	loff_t newpos;
372 	struct wil6210_priv *wil = filp->private_data;
373 	struct pmc_ctx *pmc = &wil->pmc;
374 	size_t pmc_size;
375 
376 	mutex_lock(&pmc->lock);
377 
378 	if (!wil_is_pmc_allocated(pmc)) {
379 		wil_err(wil, "error, pmc is not allocated!\n");
380 		pmc->last_cmd_status = -EPERM;
381 		mutex_unlock(&pmc->lock);
382 		return -EPERM;
383 	}
384 
385 	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
386 
387 	switch (whence) {
388 	case 0: /* SEEK_SET */
389 		newpos = off;
390 		break;
391 
392 	case 1: /* SEEK_CUR */
393 		newpos = filp->f_pos + off;
394 		break;
395 
396 	case 2: /* SEEK_END */
397 		newpos = pmc_size;
398 		break;
399 
400 	default: /* can't happen */
401 		newpos = -EINVAL;
402 		goto out;
403 	}
404 
405 	if (newpos < 0) {
406 		newpos = -EINVAL;
407 		goto out;
408 	}
409 	if (newpos > pmc_size)
410 		newpos = pmc_size;
411 
412 	filp->f_pos = newpos;
413 
414 out:
415 	mutex_unlock(&pmc->lock);
416 
417 	return newpos;
418 }
419