xref: /linux/drivers/net/wireless/ath/wil6210/pmc.c (revision 1fd1dc41724319406b0aff221a352a400b0ddfc5)
1 // SPDX-License-Identifier: ISC
2 /*
3  * Copyright (c) 2012-2015,2017 Qualcomm Atheros, Inc.
4  * Copyright (c) 2018, The Linux Foundation. All rights reserved.
5  */
6 
7 #include <linux/types.h>
8 #include <linux/errno.h>
9 #include <linux/fs.h>
10 #include <linux/seq_file.h>
11 #include "wmi.h"
12 #include "wil6210.h"
13 #include "txrx.h"
14 #include "pmc.h"
15 
16 struct desc_alloc_info {
17 	dma_addr_t pa;
18 	void	  *va;
19 };
20 
21 static int wil_is_pmc_allocated(struct pmc_ctx *pmc)
22 {
23 	return !!pmc->pring_va;
24 }
25 
26 void wil_pmc_init(struct wil6210_priv *wil)
27 {
28 	memset(&wil->pmc, 0, sizeof(struct pmc_ctx));
29 	mutex_init(&wil->pmc.lock);
30 }
31 
32 /* Allocate the physical ring (p-ring) and the required
33  * number of descriptors of required size.
34  * Initialize the descriptors as required by pmc dma.
35  * The descriptors' buffers dwords are initialized to hold
36  * dword's serial number in the lsw and reserved value
37  * PCM_DATA_INVALID_DW_VAL in the msw.
38  */
39 void wil_pmc_alloc(struct wil6210_priv *wil,
40 		   int num_descriptors,
41 		   int descriptor_size)
42 {
43 	u32 i;
44 	struct pmc_ctx *pmc = &wil->pmc;
45 	struct device *dev = wil_to_dev(wil);
46 	struct wil6210_vif *vif = ndev_to_vif(wil->main_ndev);
47 	struct wmi_pmc_cmd pmc_cmd = {0};
48 	int last_cmd_err = -ENOMEM;
49 
50 	mutex_lock(&pmc->lock);
51 
52 	if (wil_is_pmc_allocated(pmc)) {
53 		/* sanity check */
54 		wil_err(wil, "ERROR pmc is already allocated\n");
55 		goto no_release_err;
56 	}
57 	if ((num_descriptors <= 0) || (descriptor_size <= 0)) {
58 		wil_err(wil,
59 			"Invalid params num_descriptors(%d), descriptor_size(%d)\n",
60 			num_descriptors, descriptor_size);
61 		last_cmd_err = -EINVAL;
62 		goto no_release_err;
63 	}
64 
65 	if (num_descriptors > (1 << WIL_RING_SIZE_ORDER_MAX)) {
66 		wil_err(wil,
67 			"num_descriptors(%d) exceeds max ring size %d\n",
68 			num_descriptors, 1 << WIL_RING_SIZE_ORDER_MAX);
69 		last_cmd_err = -EINVAL;
70 		goto no_release_err;
71 	}
72 
73 	if (num_descriptors > INT_MAX / descriptor_size) {
74 		wil_err(wil,
75 			"Overflow in num_descriptors(%d)*descriptor_size(%d)\n",
76 			num_descriptors, descriptor_size);
77 		last_cmd_err = -EINVAL;
78 		goto no_release_err;
79 	}
80 
81 	pmc->num_descriptors = num_descriptors;
82 	pmc->descriptor_size = descriptor_size;
83 
84 	wil_dbg_misc(wil, "pmc_alloc: %d descriptors x %d bytes each\n",
85 		     num_descriptors, descriptor_size);
86 
87 	/* allocate descriptors info list in pmc context*/
88 	pmc->descriptors = kzalloc_objs(struct desc_alloc_info, num_descriptors);
89 	if (!pmc->descriptors) {
90 		wil_err(wil, "ERROR allocating pmc skb list\n");
91 		goto no_release_err;
92 	}
93 
94 	wil_dbg_misc(wil, "pmc_alloc: allocated descriptors info list %p\n",
95 		     pmc->descriptors);
96 
97 	/* Allocate pring buffer and descriptors.
98 	 * vring->va should be aligned on its size rounded up to power of 2
99 	 * This is granted by the dma_alloc_coherent.
100 	 *
101 	 * HW has limitation that all vrings addresses must share the same
102 	 * upper 16 msb bits part of 48 bits address. To workaround that,
103 	 * if we are using more than 32 bit addresses switch to 32 bit
104 	 * allocation before allocating vring memory.
105 	 *
106 	 * There's no check for the return value of dma_set_mask_and_coherent,
107 	 * since we assume if we were able to set the mask during
108 	 * initialization in this system it will not fail if we set it again
109 	 */
110 	if (wil->dma_addr_size > 32)
111 		dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
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 	if (wil->dma_addr_size > 32)
119 		dma_set_mask_and_coherent(dev,
120 					  DMA_BIT_MASK(wil->dma_addr_size));
121 
122 	wil_dbg_misc(wil,
123 		     "pmc_alloc: allocated pring %p => %pad. %zd x %d = total %zd bytes\n",
124 		     pmc->pring_va, &pmc->pring_pa,
125 		     sizeof(struct vring_tx_desc),
126 		     num_descriptors,
127 		     sizeof(struct vring_tx_desc) * num_descriptors);
128 
129 	if (!pmc->pring_va) {
130 		wil_err(wil, "ERROR allocating pmc pring\n");
131 		goto release_pmc_skb_list;
132 	}
133 
134 	/* initially, all descriptors are SW owned
135 	 * For Tx, Rx, and PMC, ownership bit is at the same location, thus
136 	 * we can use any
137 	 */
138 	for (i = 0; i < num_descriptors; i++) {
139 		struct vring_tx_desc *_d = &pmc->pring_va[i];
140 		struct vring_tx_desc dd = {}, *d = &dd;
141 		int j = 0;
142 
143 		pmc->descriptors[i].va = dma_alloc_coherent(dev,
144 			descriptor_size,
145 			&pmc->descriptors[i].pa,
146 			GFP_KERNEL);
147 
148 		if (unlikely(!pmc->descriptors[i].va)) {
149 			wil_err(wil, "ERROR allocating pmc descriptor %d", i);
150 			goto release_pmc_skbs;
151 		}
152 
153 		for (j = 0; j < descriptor_size / sizeof(u32); j++) {
154 			u32 *p = (u32 *)pmc->descriptors[i].va + j;
155 			*p = PCM_DATA_INVALID_DW_VAL | j;
156 		}
157 
158 		/* configure dma descriptor */
159 		d->dma.addr.addr_low =
160 			cpu_to_le32(lower_32_bits(pmc->descriptors[i].pa));
161 		d->dma.addr.addr_high =
162 			cpu_to_le16((u16)upper_32_bits(pmc->descriptors[i].pa));
163 		d->dma.status = 0; /* 0 = HW_OWNED */
164 		d->dma.length = cpu_to_le16(descriptor_size);
165 		d->dma.d0 = BIT(9) | RX_DMA_D0_CMD_DMA_IT;
166 		*_d = *d;
167 	}
168 
169 	wil_dbg_misc(wil, "pmc_alloc: allocated successfully\n");
170 
171 	pmc_cmd.op = WMI_PMC_ALLOCATE;
172 	pmc_cmd.ring_size = cpu_to_le16(pmc->num_descriptors);
173 	pmc_cmd.mem_base = cpu_to_le64(pmc->pring_pa);
174 
175 	wil_dbg_misc(wil, "pmc_alloc: send WMI_PMC_CMD with ALLOCATE op\n");
176 	pmc->last_cmd_status = wmi_send(wil,
177 					WMI_PMC_CMDID,
178 					vif->mid,
179 					&pmc_cmd,
180 					sizeof(pmc_cmd));
181 	if (pmc->last_cmd_status) {
182 		wil_err(wil,
183 			"WMI_PMC_CMD with ALLOCATE op failed with status %d",
184 			pmc->last_cmd_status);
185 		goto release_pmc_skbs;
186 	}
187 
188 	mutex_unlock(&pmc->lock);
189 
190 	return;
191 
192 release_pmc_skbs:
193 	wil_err(wil, "exit on error: Releasing skbs...\n");
194 	for (i = 0; i < num_descriptors && pmc->descriptors[i].va; i++) {
195 		dma_free_coherent(dev,
196 				  descriptor_size,
197 				  pmc->descriptors[i].va,
198 				  pmc->descriptors[i].pa);
199 
200 		pmc->descriptors[i].va = NULL;
201 	}
202 	wil_err(wil, "exit on error: Releasing pring...\n");
203 
204 	dma_free_coherent(dev,
205 			  sizeof(struct vring_tx_desc) * num_descriptors,
206 			  pmc->pring_va,
207 			  pmc->pring_pa);
208 
209 	pmc->pring_va = NULL;
210 
211 release_pmc_skb_list:
212 	wil_err(wil, "exit on error: Releasing descriptors info list...\n");
213 	kfree(pmc->descriptors);
214 	pmc->descriptors = NULL;
215 
216 no_release_err:
217 	pmc->last_cmd_status = last_cmd_err;
218 	mutex_unlock(&pmc->lock);
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 wil6210_vif *vif = ndev_to_vif(wil->main_ndev);
229 	struct wmi_pmc_cmd pmc_cmd = {0};
230 
231 	mutex_lock(&pmc->lock);
232 
233 	pmc->last_cmd_status = 0;
234 
235 	if (!wil_is_pmc_allocated(pmc)) {
236 		wil_dbg_misc(wil,
237 			     "pmc_free: Error, can't free - not allocated\n");
238 		pmc->last_cmd_status = -EPERM;
239 		mutex_unlock(&pmc->lock);
240 		return;
241 	}
242 
243 	if (send_pmc_cmd) {
244 		wil_dbg_misc(wil, "send WMI_PMC_CMD with RELEASE op\n");
245 		pmc_cmd.op = WMI_PMC_RELEASE;
246 		pmc->last_cmd_status =
247 				wmi_send(wil, WMI_PMC_CMDID, vif->mid,
248 					 &pmc_cmd, sizeof(pmc_cmd));
249 		if (pmc->last_cmd_status) {
250 			wil_err(wil,
251 				"WMI_PMC_CMD with RELEASE op failed, status %d",
252 				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, "pmc_free: free pring va %p\n",
265 			     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 		     i < pmc->num_descriptors && pmc->descriptors[i].va; 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, "pmc_free: free descriptor info %d/%d\n", i,
285 			     pmc->num_descriptors);
286 		wil_dbg_misc(wil,
287 			     "pmc_free: free pmc descriptors info list %p\n",
288 			     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 /* Status of the last operation requested via debugfs: alloc/free/read.
299  * 0 - success or negative errno
300  */
301 int wil_pmc_last_cmd_status(struct wil6210_priv *wil)
302 {
303 	wil_dbg_misc(wil, "pmc_last_cmd_status: status %d\n",
304 		     wil->pmc.last_cmd_status);
305 
306 	return wil->pmc.last_cmd_status;
307 }
308 
309 /* Read from required position up to the end of current descriptor,
310  * depends on descriptor size configured during alloc request.
311  */
312 ssize_t wil_pmc_read(struct file *filp, char __user *buf, size_t count,
313 		     loff_t *f_pos)
314 {
315 	struct wil6210_priv *wil = filp->private_data;
316 	struct pmc_ctx *pmc = &wil->pmc;
317 	size_t retval = 0;
318 	unsigned long long idx;
319 	loff_t offset;
320 	size_t pmc_size;
321 
322 	mutex_lock(&pmc->lock);
323 
324 	if (!wil_is_pmc_allocated(pmc)) {
325 		wil_err(wil, "error, pmc is not allocated!\n");
326 		pmc->last_cmd_status = -EPERM;
327 		mutex_unlock(&pmc->lock);
328 		return -EPERM;
329 	}
330 
331 	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
332 
333 	wil_dbg_misc(wil,
334 		     "pmc_read: size %u, pos %lld\n",
335 		     (u32)count, *f_pos);
336 
337 	pmc->last_cmd_status = 0;
338 
339 	idx = *f_pos;
340 	do_div(idx, pmc->descriptor_size);
341 	offset = *f_pos - (idx * pmc->descriptor_size);
342 
343 	if (*f_pos >= pmc_size) {
344 		wil_dbg_misc(wil,
345 			     "pmc_read: reached end of pmc buf: %lld >= %u\n",
346 			     *f_pos, (u32)pmc_size);
347 		pmc->last_cmd_status = -ERANGE;
348 		goto out;
349 	}
350 
351 	wil_dbg_misc(wil,
352 		     "pmc_read: read from pos %lld (descriptor %llu, offset %llu) %zu bytes\n",
353 		     *f_pos, idx, offset, count);
354 
355 	/* if no errors, return the copied byte count */
356 	retval = simple_read_from_buffer(buf,
357 					 count,
358 					 &offset,
359 					 pmc->descriptors[idx].va,
360 					 pmc->descriptor_size);
361 	*f_pos += retval;
362 out:
363 	mutex_unlock(&pmc->lock);
364 
365 	return retval;
366 }
367 
368 loff_t wil_pmc_llseek(struct file *filp, loff_t off, int whence)
369 {
370 	loff_t newpos;
371 	struct wil6210_priv *wil = filp->private_data;
372 	struct pmc_ctx *pmc = &wil->pmc;
373 	size_t pmc_size;
374 
375 	mutex_lock(&pmc->lock);
376 
377 	if (!wil_is_pmc_allocated(pmc)) {
378 		wil_err(wil, "error, pmc is not allocated!\n");
379 		pmc->last_cmd_status = -EPERM;
380 		mutex_unlock(&pmc->lock);
381 		return -EPERM;
382 	}
383 
384 	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
385 
386 	switch (whence) {
387 	case 0: /* SEEK_SET */
388 		newpos = off;
389 		break;
390 
391 	case 1: /* SEEK_CUR */
392 		newpos = filp->f_pos + off;
393 		break;
394 
395 	case 2: /* SEEK_END */
396 		newpos = pmc_size;
397 		break;
398 
399 	default: /* can't happen */
400 		newpos = -EINVAL;
401 		goto out;
402 	}
403 
404 	if (newpos < 0) {
405 		newpos = -EINVAL;
406 		goto out;
407 	}
408 	if (newpos > pmc_size)
409 		newpos = pmc_size;
410 
411 	filp->f_pos = newpos;
412 
413 out:
414 	mutex_unlock(&pmc->lock);
415 
416 	return newpos;
417 }
418 
419 int wil_pmcring_read(struct seq_file *s, void *data)
420 {
421 	struct wil6210_priv *wil = s->private;
422 	struct pmc_ctx *pmc = &wil->pmc;
423 	size_t pmc_ring_size =
424 		sizeof(struct vring_rx_desc) * pmc->num_descriptors;
425 
426 	mutex_lock(&pmc->lock);
427 
428 	if (!wil_is_pmc_allocated(pmc)) {
429 		wil_err(wil, "error, pmc is not allocated!\n");
430 		pmc->last_cmd_status = -EPERM;
431 		mutex_unlock(&pmc->lock);
432 		return -EPERM;
433 	}
434 
435 	wil_dbg_misc(wil, "pmcring_read: size %zu\n", pmc_ring_size);
436 
437 	seq_write(s, pmc->pring_va, pmc_ring_size);
438 
439 	mutex_unlock(&pmc->lock);
440 
441 	return 0;
442 }
443