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 48 bit addresses switch to 32 bit allocation
115 	 * 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->use_extended_dma_addr)
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->use_extended_dma_addr)
130 		dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48));
131 
132 	wil_dbg_misc(wil,
133 		     "pmc_alloc: allocated pring %p => %pad. %zd x %d = total %zd bytes\n",
134 		     pmc->pring_va, &pmc->pring_pa,
135 		     sizeof(struct vring_tx_desc),
136 		     num_descriptors,
137 		     sizeof(struct vring_tx_desc) * num_descriptors);
138 
139 	if (!pmc->pring_va) {
140 		wil_err(wil, "ERROR allocating pmc pring\n");
141 		goto release_pmc_skb_list;
142 	}
143 
144 	/* initially, all descriptors are SW owned
145 	 * For Tx, Rx, and PMC, ownership bit is at the same location, thus
146 	 * we can use any
147 	 */
148 	for (i = 0; i < num_descriptors; i++) {
149 		struct vring_tx_desc *_d = &pmc->pring_va[i];
150 		struct vring_tx_desc dd = {}, *d = &dd;
151 		int j = 0;
152 
153 		pmc->descriptors[i].va = dma_alloc_coherent(dev,
154 			descriptor_size,
155 			&pmc->descriptors[i].pa,
156 			GFP_KERNEL);
157 
158 		if (unlikely(!pmc->descriptors[i].va)) {
159 			wil_err(wil, "ERROR allocating pmc descriptor %d", i);
160 			goto release_pmc_skbs;
161 		}
162 
163 		for (j = 0; j < descriptor_size / sizeof(u32); j++) {
164 			u32 *p = (u32 *)pmc->descriptors[i].va + j;
165 			*p = PCM_DATA_INVALID_DW_VAL | j;
166 		}
167 
168 		/* configure dma descriptor */
169 		d->dma.addr.addr_low =
170 			cpu_to_le32(lower_32_bits(pmc->descriptors[i].pa));
171 		d->dma.addr.addr_high =
172 			cpu_to_le16((u16)upper_32_bits(pmc->descriptors[i].pa));
173 		d->dma.status = 0; /* 0 = HW_OWNED */
174 		d->dma.length = cpu_to_le16(descriptor_size);
175 		d->dma.d0 = BIT(9) | RX_DMA_D0_CMD_DMA_IT;
176 		*_d = *d;
177 	}
178 
179 	wil_dbg_misc(wil, "pmc_alloc: allocated successfully\n");
180 
181 	pmc_cmd.op = WMI_PMC_ALLOCATE;
182 	pmc_cmd.ring_size = cpu_to_le16(pmc->num_descriptors);
183 	pmc_cmd.mem_base = cpu_to_le64(pmc->pring_pa);
184 
185 	wil_dbg_misc(wil, "pmc_alloc: send WMI_PMC_CMD with ALLOCATE op\n");
186 	pmc->last_cmd_status = wmi_send(wil,
187 					WMI_PMC_CMDID,
188 					&pmc_cmd,
189 					sizeof(pmc_cmd));
190 	if (pmc->last_cmd_status) {
191 		wil_err(wil,
192 			"WMI_PMC_CMD with ALLOCATE op failed with status %d",
193 			pmc->last_cmd_status);
194 		goto release_pmc_skbs;
195 	}
196 
197 	mutex_unlock(&pmc->lock);
198 
199 	return;
200 
201 release_pmc_skbs:
202 	wil_err(wil, "exit on error: Releasing skbs...\n");
203 	for (i = 0; i < num_descriptors && pmc->descriptors[i].va; i++) {
204 		dma_free_coherent(dev,
205 				  descriptor_size,
206 				  pmc->descriptors[i].va,
207 				  pmc->descriptors[i].pa);
208 
209 		pmc->descriptors[i].va = NULL;
210 	}
211 	wil_err(wil, "exit on error: Releasing pring...\n");
212 
213 	dma_free_coherent(dev,
214 			  sizeof(struct vring_tx_desc) * num_descriptors,
215 			  pmc->pring_va,
216 			  pmc->pring_pa);
217 
218 	pmc->pring_va = NULL;
219 
220 release_pmc_skb_list:
221 	wil_err(wil, "exit on error: Releasing descriptors info list...\n");
222 	kfree(pmc->descriptors);
223 	pmc->descriptors = NULL;
224 
225 no_release_err:
226 	pmc->last_cmd_status = last_cmd_err;
227 	mutex_unlock(&pmc->lock);
228 }
229 
230 /**
231  * Traverse the p-ring and release all buffers.
232  * At the end release the p-ring memory
233  */
234 void wil_pmc_free(struct wil6210_priv *wil, int send_pmc_cmd)
235 {
236 	struct pmc_ctx *pmc = &wil->pmc;
237 	struct device *dev = wil_to_dev(wil);
238 	struct wmi_pmc_cmd pmc_cmd = {0};
239 
240 	mutex_lock(&pmc->lock);
241 
242 	pmc->last_cmd_status = 0;
243 
244 	if (!wil_is_pmc_allocated(pmc)) {
245 		wil_dbg_misc(wil,
246 			     "pmc_free: Error, can't free - not allocated\n");
247 		pmc->last_cmd_status = -EPERM;
248 		mutex_unlock(&pmc->lock);
249 		return;
250 	}
251 
252 	if (send_pmc_cmd) {
253 		wil_dbg_misc(wil, "send WMI_PMC_CMD with RELEASE op\n");
254 		pmc_cmd.op = WMI_PMC_RELEASE;
255 		pmc->last_cmd_status =
256 				wmi_send(wil, WMI_PMC_CMDID, &pmc_cmd,
257 					 sizeof(pmc_cmd));
258 		if (pmc->last_cmd_status) {
259 			wil_err(wil,
260 				"WMI_PMC_CMD with RELEASE op failed, status %d",
261 				pmc->last_cmd_status);
262 			/* There's nothing we can do with this error.
263 			 * Normally, it should never occur.
264 			 * Continue to freeing all memory allocated for pmc.
265 			 */
266 		}
267 	}
268 
269 	if (pmc->pring_va) {
270 		size_t buf_size = sizeof(struct vring_tx_desc) *
271 				  pmc->num_descriptors;
272 
273 		wil_dbg_misc(wil, "pmc_free: free pring va %p\n",
274 			     pmc->pring_va);
275 		dma_free_coherent(dev, buf_size, pmc->pring_va, pmc->pring_pa);
276 
277 		pmc->pring_va = NULL;
278 	} else {
279 		pmc->last_cmd_status = -ENOENT;
280 	}
281 
282 	if (pmc->descriptors) {
283 		int i;
284 
285 		for (i = 0;
286 		     i < pmc->num_descriptors && pmc->descriptors[i].va; i++) {
287 			dma_free_coherent(dev,
288 					  pmc->descriptor_size,
289 					  pmc->descriptors[i].va,
290 					  pmc->descriptors[i].pa);
291 			pmc->descriptors[i].va = NULL;
292 		}
293 		wil_dbg_misc(wil, "pmc_free: free descriptor info %d/%d\n", i,
294 			     pmc->num_descriptors);
295 		wil_dbg_misc(wil,
296 			     "pmc_free: free pmc descriptors info list %p\n",
297 			     pmc->descriptors);
298 		kfree(pmc->descriptors);
299 		pmc->descriptors = NULL;
300 	} else {
301 		pmc->last_cmd_status = -ENOENT;
302 	}
303 
304 	mutex_unlock(&pmc->lock);
305 }
306 
307 /**
308  * Status of the last operation requested via debugfs: alloc/free/read.
309  * 0 - success or negative errno
310  */
311 int wil_pmc_last_cmd_status(struct wil6210_priv *wil)
312 {
313 	wil_dbg_misc(wil, "pmc_last_cmd_status: status %d\n",
314 		     wil->pmc.last_cmd_status);
315 
316 	return wil->pmc.last_cmd_status;
317 }
318 
319 /**
320  * Read from required position up to the end of current descriptor,
321  * depends on descriptor size configured during alloc request.
322  */
323 ssize_t wil_pmc_read(struct file *filp, char __user *buf, size_t count,
324 		     loff_t *f_pos)
325 {
326 	struct wil6210_priv *wil = filp->private_data;
327 	struct pmc_ctx *pmc = &wil->pmc;
328 	size_t retval = 0;
329 	unsigned long long idx;
330 	loff_t offset;
331 	size_t pmc_size;
332 
333 	mutex_lock(&pmc->lock);
334 
335 	if (!wil_is_pmc_allocated(pmc)) {
336 		wil_err(wil, "error, pmc is not allocated!\n");
337 		pmc->last_cmd_status = -EPERM;
338 		mutex_unlock(&pmc->lock);
339 		return -EPERM;
340 	}
341 
342 	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
343 
344 	wil_dbg_misc(wil,
345 		     "pmc_read: size %u, pos %lld\n",
346 		     (u32)count, *f_pos);
347 
348 	pmc->last_cmd_status = 0;
349 
350 	idx = *f_pos;
351 	do_div(idx, pmc->descriptor_size);
352 	offset = *f_pos - (idx * pmc->descriptor_size);
353 
354 	if (*f_pos >= pmc_size) {
355 		wil_dbg_misc(wil,
356 			     "pmc_read: reached end of pmc buf: %lld >= %u\n",
357 			     *f_pos, (u32)pmc_size);
358 		pmc->last_cmd_status = -ERANGE;
359 		goto out;
360 	}
361 
362 	wil_dbg_misc(wil,
363 		     "pmc_read: read from pos %lld (descriptor %llu, offset %llu) %zu bytes\n",
364 		     *f_pos, idx, offset, count);
365 
366 	/* if no errors, return the copied byte count */
367 	retval = simple_read_from_buffer(buf,
368 					 count,
369 					 &offset,
370 					 pmc->descriptors[idx].va,
371 					 pmc->descriptor_size);
372 	*f_pos += retval;
373 out:
374 	mutex_unlock(&pmc->lock);
375 
376 	return retval;
377 }
378 
379 loff_t wil_pmc_llseek(struct file *filp, loff_t off, int whence)
380 {
381 	loff_t newpos;
382 	struct wil6210_priv *wil = filp->private_data;
383 	struct pmc_ctx *pmc = &wil->pmc;
384 	size_t pmc_size;
385 
386 	mutex_lock(&pmc->lock);
387 
388 	if (!wil_is_pmc_allocated(pmc)) {
389 		wil_err(wil, "error, pmc is not allocated!\n");
390 		pmc->last_cmd_status = -EPERM;
391 		mutex_unlock(&pmc->lock);
392 		return -EPERM;
393 	}
394 
395 	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
396 
397 	switch (whence) {
398 	case 0: /* SEEK_SET */
399 		newpos = off;
400 		break;
401 
402 	case 1: /* SEEK_CUR */
403 		newpos = filp->f_pos + off;
404 		break;
405 
406 	case 2: /* SEEK_END */
407 		newpos = pmc_size;
408 		break;
409 
410 	default: /* can't happen */
411 		newpos = -EINVAL;
412 		goto out;
413 	}
414 
415 	if (newpos < 0) {
416 		newpos = -EINVAL;
417 		goto out;
418 	}
419 	if (newpos > pmc_size)
420 		newpos = pmc_size;
421 
422 	filp->f_pos = newpos;
423 
424 out:
425 	mutex_unlock(&pmc->lock);
426 
427 	return newpos;
428 }
429