xref: /linux/drivers/net/wireless/ath/wil6210/pmc.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 	pmc->pring_va = dma_alloc_coherent(dev,
113 			sizeof(struct vring_tx_desc) * num_descriptors,
114 			&pmc->pring_pa,
115 			GFP_KERNEL);
116 
117 	wil_dbg_misc(wil,
118 		     "pmc_alloc: allocated pring %p => %pad. %zd x %d = total %zd bytes\n",
119 		     pmc->pring_va, &pmc->pring_pa,
120 		     sizeof(struct vring_tx_desc),
121 		     num_descriptors,
122 		     sizeof(struct vring_tx_desc) * num_descriptors);
123 
124 	if (!pmc->pring_va) {
125 		wil_err(wil, "ERROR allocating pmc pring\n");
126 		goto release_pmc_skb_list;
127 	}
128 
129 	/* initially, all descriptors are SW owned
130 	 * For Tx, Rx, and PMC, ownership bit is at the same location, thus
131 	 * we can use any
132 	 */
133 	for (i = 0; i < num_descriptors; i++) {
134 		struct vring_tx_desc *_d = &pmc->pring_va[i];
135 		struct vring_tx_desc dd = {}, *d = &dd;
136 		int j = 0;
137 
138 		pmc->descriptors[i].va = dma_alloc_coherent(dev,
139 			descriptor_size,
140 			&pmc->descriptors[i].pa,
141 			GFP_KERNEL);
142 
143 		if (unlikely(!pmc->descriptors[i].va)) {
144 			wil_err(wil, "ERROR allocating pmc descriptor %d", i);
145 			goto release_pmc_skbs;
146 		}
147 
148 		for (j = 0; j < descriptor_size / sizeof(u32); j++) {
149 			u32 *p = (u32 *)pmc->descriptors[i].va + j;
150 			*p = PCM_DATA_INVALID_DW_VAL | j;
151 		}
152 
153 		/* configure dma descriptor */
154 		d->dma.addr.addr_low =
155 			cpu_to_le32(lower_32_bits(pmc->descriptors[i].pa));
156 		d->dma.addr.addr_high =
157 			cpu_to_le16((u16)upper_32_bits(pmc->descriptors[i].pa));
158 		d->dma.status = 0; /* 0 = HW_OWNED */
159 		d->dma.length = cpu_to_le16(descriptor_size);
160 		d->dma.d0 = BIT(9) | RX_DMA_D0_CMD_DMA_IT;
161 		*_d = *d;
162 	}
163 
164 	wil_dbg_misc(wil, "pmc_alloc: allocated successfully\n");
165 
166 	pmc_cmd.op = WMI_PMC_ALLOCATE;
167 	pmc_cmd.ring_size = cpu_to_le16(pmc->num_descriptors);
168 	pmc_cmd.mem_base = cpu_to_le64(pmc->pring_pa);
169 
170 	wil_dbg_misc(wil, "pmc_alloc: send WMI_PMC_CMD with ALLOCATE op\n");
171 	pmc->last_cmd_status = wmi_send(wil,
172 					WMI_PMC_CMDID,
173 					&pmc_cmd,
174 					sizeof(pmc_cmd));
175 	if (pmc->last_cmd_status) {
176 		wil_err(wil,
177 			"WMI_PMC_CMD with ALLOCATE op failed with status %d",
178 			pmc->last_cmd_status);
179 		goto release_pmc_skbs;
180 	}
181 
182 	mutex_unlock(&pmc->lock);
183 
184 	return;
185 
186 release_pmc_skbs:
187 	wil_err(wil, "exit on error: Releasing skbs...\n");
188 	for (i = 0; pmc->descriptors[i].va && i < num_descriptors; i++) {
189 		dma_free_coherent(dev,
190 				  descriptor_size,
191 				  pmc->descriptors[i].va,
192 				  pmc->descriptors[i].pa);
193 
194 		pmc->descriptors[i].va = NULL;
195 	}
196 	wil_err(wil, "exit on error: Releasing pring...\n");
197 
198 	dma_free_coherent(dev,
199 			  sizeof(struct vring_tx_desc) * num_descriptors,
200 			  pmc->pring_va,
201 			  pmc->pring_pa);
202 
203 	pmc->pring_va = NULL;
204 
205 release_pmc_skb_list:
206 	wil_err(wil, "exit on error: Releasing descriptors info list...\n");
207 	kfree(pmc->descriptors);
208 	pmc->descriptors = NULL;
209 
210 no_release_err:
211 	pmc->last_cmd_status = last_cmd_err;
212 	mutex_unlock(&pmc->lock);
213 }
214 
215 /**
216  * Traverse the p-ring and release all buffers.
217  * At the end release the p-ring memory
218  */
219 void wil_pmc_free(struct wil6210_priv *wil, int send_pmc_cmd)
220 {
221 	struct pmc_ctx *pmc = &wil->pmc;
222 	struct device *dev = wil_to_dev(wil);
223 	struct wmi_pmc_cmd pmc_cmd = {0};
224 
225 	mutex_lock(&pmc->lock);
226 
227 	pmc->last_cmd_status = 0;
228 
229 	if (!wil_is_pmc_allocated(pmc)) {
230 		wil_dbg_misc(wil,
231 			     "pmc_free: Error, can't free - not allocated\n");
232 		pmc->last_cmd_status = -EPERM;
233 		mutex_unlock(&pmc->lock);
234 		return;
235 	}
236 
237 	if (send_pmc_cmd) {
238 		wil_dbg_misc(wil, "send WMI_PMC_CMD with RELEASE op\n");
239 		pmc_cmd.op = WMI_PMC_RELEASE;
240 		pmc->last_cmd_status =
241 				wmi_send(wil, WMI_PMC_CMDID, &pmc_cmd,
242 					 sizeof(pmc_cmd));
243 		if (pmc->last_cmd_status) {
244 			wil_err(wil,
245 				"WMI_PMC_CMD with RELEASE op failed, status %d",
246 				pmc->last_cmd_status);
247 			/* There's nothing we can do with this error.
248 			 * Normally, it should never occur.
249 			 * Continue to freeing all memory allocated for pmc.
250 			 */
251 		}
252 	}
253 
254 	if (pmc->pring_va) {
255 		size_t buf_size = sizeof(struct vring_tx_desc) *
256 				  pmc->num_descriptors;
257 
258 		wil_dbg_misc(wil, "pmc_free: free pring va %p\n",
259 			     pmc->pring_va);
260 		dma_free_coherent(dev, buf_size, pmc->pring_va, pmc->pring_pa);
261 
262 		pmc->pring_va = NULL;
263 	} else {
264 		pmc->last_cmd_status = -ENOENT;
265 	}
266 
267 	if (pmc->descriptors) {
268 		int i;
269 
270 		for (i = 0;
271 		     pmc->descriptors[i].va && i < pmc->num_descriptors; i++) {
272 			dma_free_coherent(dev,
273 					  pmc->descriptor_size,
274 					  pmc->descriptors[i].va,
275 					  pmc->descriptors[i].pa);
276 			pmc->descriptors[i].va = NULL;
277 		}
278 		wil_dbg_misc(wil, "pmc_free: free descriptor info %d/%d\n", i,
279 			     pmc->num_descriptors);
280 		wil_dbg_misc(wil,
281 			     "pmc_free: free pmc descriptors info list %p\n",
282 			     pmc->descriptors);
283 		kfree(pmc->descriptors);
284 		pmc->descriptors = NULL;
285 	} else {
286 		pmc->last_cmd_status = -ENOENT;
287 	}
288 
289 	mutex_unlock(&pmc->lock);
290 }
291 
292 /**
293  * Status of the last operation requested via debugfs: alloc/free/read.
294  * 0 - success or negative errno
295  */
296 int wil_pmc_last_cmd_status(struct wil6210_priv *wil)
297 {
298 	wil_dbg_misc(wil, "pmc_last_cmd_status: status %d\n",
299 		     wil->pmc.last_cmd_status);
300 
301 	return wil->pmc.last_cmd_status;
302 }
303 
304 /**
305  * Read from required position up to the end of current descriptor,
306  * depends on descriptor size configured during alloc request.
307  */
308 ssize_t wil_pmc_read(struct file *filp, char __user *buf, size_t count,
309 		     loff_t *f_pos)
310 {
311 	struct wil6210_priv *wil = filp->private_data;
312 	struct pmc_ctx *pmc = &wil->pmc;
313 	size_t retval = 0;
314 	unsigned long long idx;
315 	loff_t offset;
316 	size_t pmc_size;
317 
318 	mutex_lock(&pmc->lock);
319 
320 	if (!wil_is_pmc_allocated(pmc)) {
321 		wil_err(wil, "error, pmc is not allocated!\n");
322 		pmc->last_cmd_status = -EPERM;
323 		mutex_unlock(&pmc->lock);
324 		return -EPERM;
325 	}
326 
327 	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
328 
329 	wil_dbg_misc(wil,
330 		     "pmc_read: size %u, pos %lld\n",
331 		     (u32)count, *f_pos);
332 
333 	pmc->last_cmd_status = 0;
334 
335 	idx = *f_pos;
336 	do_div(idx, pmc->descriptor_size);
337 	offset = *f_pos - (idx * pmc->descriptor_size);
338 
339 	if (*f_pos >= pmc_size) {
340 		wil_dbg_misc(wil,
341 			     "pmc_read: reached end of pmc buf: %lld >= %u\n",
342 			     *f_pos, (u32)pmc_size);
343 		pmc->last_cmd_status = -ERANGE;
344 		goto out;
345 	}
346 
347 	wil_dbg_misc(wil,
348 		     "pmc_read: read from pos %lld (descriptor %llu, offset %llu) %zu bytes\n",
349 		     *f_pos, idx, offset, count);
350 
351 	/* if no errors, return the copied byte count */
352 	retval = simple_read_from_buffer(buf,
353 					 count,
354 					 &offset,
355 					 pmc->descriptors[idx].va,
356 					 pmc->descriptor_size);
357 	*f_pos += retval;
358 out:
359 	mutex_unlock(&pmc->lock);
360 
361 	return retval;
362 }
363 
364 loff_t wil_pmc_llseek(struct file *filp, loff_t off, int whence)
365 {
366 	loff_t newpos;
367 	struct wil6210_priv *wil = filp->private_data;
368 	struct pmc_ctx *pmc = &wil->pmc;
369 	size_t pmc_size;
370 
371 	mutex_lock(&pmc->lock);
372 
373 	if (!wil_is_pmc_allocated(pmc)) {
374 		wil_err(wil, "error, pmc is not allocated!\n");
375 		pmc->last_cmd_status = -EPERM;
376 		mutex_unlock(&pmc->lock);
377 		return -EPERM;
378 	}
379 
380 	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
381 
382 	switch (whence) {
383 	case 0: /* SEEK_SET */
384 		newpos = off;
385 		break;
386 
387 	case 1: /* SEEK_CUR */
388 		newpos = filp->f_pos + off;
389 		break;
390 
391 	case 2: /* SEEK_END */
392 		newpos = pmc_size;
393 		break;
394 
395 	default: /* can't happen */
396 		newpos = -EINVAL;
397 		goto out;
398 	}
399 
400 	if (newpos < 0) {
401 		newpos = -EINVAL;
402 		goto out;
403 	}
404 	if (newpos > pmc_size)
405 		newpos = pmc_size;
406 
407 	filp->f_pos = newpos;
408 
409 out:
410 	mutex_unlock(&pmc->lock);
411 
412 	return newpos;
413 }
414