xref: /linux/drivers/net/wireless/ath/wil6210/pmc.c (revision 666ed8bfd1de3b091cf32ca03b651757dd86cfff)
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 /**
33  * Allocate the physical ring (p-ring) and the required
34  * number of descriptors of required size.
35  * Initialize the descriptors as required by pmc dma.
36  * The descriptors' buffers dwords are initialized to hold
37  * dword's serial number in the lsw and reserved value
38  * PCM_DATA_INVALID_DW_VAL in the msw.
39  */
40 void wil_pmc_alloc(struct wil6210_priv *wil,
41 		   int num_descriptors,
42 		   int descriptor_size)
43 {
44 	u32 i;
45 	struct pmc_ctx *pmc = &wil->pmc;
46 	struct device *dev = wil_to_dev(wil);
47 	struct wil6210_vif *vif = ndev_to_vif(wil->main_ndev);
48 	struct wmi_pmc_cmd pmc_cmd = {0};
49 	int last_cmd_err = -ENOMEM;
50 
51 	mutex_lock(&pmc->lock);
52 
53 	if (wil_is_pmc_allocated(pmc)) {
54 		/* sanity check */
55 		wil_err(wil, "ERROR pmc is already allocated\n");
56 		goto no_release_err;
57 	}
58 	if ((num_descriptors <= 0) || (descriptor_size <= 0)) {
59 		wil_err(wil,
60 			"Invalid params num_descriptors(%d), descriptor_size(%d)\n",
61 			num_descriptors, descriptor_size);
62 		last_cmd_err = -EINVAL;
63 		goto no_release_err;
64 	}
65 
66 	if (num_descriptors > (1 << WIL_RING_SIZE_ORDER_MAX)) {
67 		wil_err(wil,
68 			"num_descriptors(%d) exceeds max ring size %d\n",
69 			num_descriptors, 1 << WIL_RING_SIZE_ORDER_MAX);
70 		last_cmd_err = -EINVAL;
71 		goto no_release_err;
72 	}
73 
74 	if (num_descriptors > INT_MAX / descriptor_size) {
75 		wil_err(wil,
76 			"Overflow in num_descriptors(%d)*descriptor_size(%d)\n",
77 			num_descriptors, descriptor_size);
78 		last_cmd_err = -EINVAL;
79 		goto no_release_err;
80 	}
81 
82 	pmc->num_descriptors = num_descriptors;
83 	pmc->descriptor_size = descriptor_size;
84 
85 	wil_dbg_misc(wil, "pmc_alloc: %d descriptors x %d bytes each\n",
86 		     num_descriptors, descriptor_size);
87 
88 	/* allocate descriptors info list in pmc context*/
89 	pmc->descriptors = kcalloc(num_descriptors,
90 				  sizeof(struct desc_alloc_info),
91 				  GFP_KERNEL);
92 	if (!pmc->descriptors) {
93 		wil_err(wil, "ERROR allocating pmc skb list\n");
94 		goto no_release_err;
95 	}
96 
97 	wil_dbg_misc(wil, "pmc_alloc: allocated descriptors info list %p\n",
98 		     pmc->descriptors);
99 
100 	/* Allocate pring buffer and descriptors.
101 	 * vring->va should be aligned on its size rounded up to power of 2
102 	 * This is granted by the dma_alloc_coherent.
103 	 *
104 	 * HW has limitation that all vrings addresses must share the same
105 	 * upper 16 msb bits part of 48 bits address. To workaround that,
106 	 * if we are using more than 32 bit addresses switch to 32 bit
107 	 * allocation before allocating vring memory.
108 	 *
109 	 * There's no check for the return value of dma_set_mask_and_coherent,
110 	 * since we assume if we were able to set the mask during
111 	 * initialization in this system it will not fail if we set it again
112 	 */
113 	if (wil->dma_addr_size > 32)
114 		dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
115 
116 	pmc->pring_va = dma_alloc_coherent(dev,
117 			sizeof(struct vring_tx_desc) * num_descriptors,
118 			&pmc->pring_pa,
119 			GFP_KERNEL);
120 
121 	if (wil->dma_addr_size > 32)
122 		dma_set_mask_and_coherent(dev,
123 					  DMA_BIT_MASK(wil->dma_addr_size));
124 
125 	wil_dbg_misc(wil,
126 		     "pmc_alloc: allocated pring %p => %pad. %zd x %d = total %zd bytes\n",
127 		     pmc->pring_va, &pmc->pring_pa,
128 		     sizeof(struct vring_tx_desc),
129 		     num_descriptors,
130 		     sizeof(struct vring_tx_desc) * num_descriptors);
131 
132 	if (!pmc->pring_va) {
133 		wil_err(wil, "ERROR allocating pmc pring\n");
134 		goto release_pmc_skb_list;
135 	}
136 
137 	/* initially, all descriptors are SW owned
138 	 * For Tx, Rx, and PMC, ownership bit is at the same location, thus
139 	 * we can use any
140 	 */
141 	for (i = 0; i < num_descriptors; i++) {
142 		struct vring_tx_desc *_d = &pmc->pring_va[i];
143 		struct vring_tx_desc dd = {}, *d = &dd;
144 		int j = 0;
145 
146 		pmc->descriptors[i].va = dma_alloc_coherent(dev,
147 			descriptor_size,
148 			&pmc->descriptors[i].pa,
149 			GFP_KERNEL);
150 
151 		if (unlikely(!pmc->descriptors[i].va)) {
152 			wil_err(wil, "ERROR allocating pmc descriptor %d", i);
153 			goto release_pmc_skbs;
154 		}
155 
156 		for (j = 0; j < descriptor_size / sizeof(u32); j++) {
157 			u32 *p = (u32 *)pmc->descriptors[i].va + j;
158 			*p = PCM_DATA_INVALID_DW_VAL | j;
159 		}
160 
161 		/* configure dma descriptor */
162 		d->dma.addr.addr_low =
163 			cpu_to_le32(lower_32_bits(pmc->descriptors[i].pa));
164 		d->dma.addr.addr_high =
165 			cpu_to_le16((u16)upper_32_bits(pmc->descriptors[i].pa));
166 		d->dma.status = 0; /* 0 = HW_OWNED */
167 		d->dma.length = cpu_to_le16(descriptor_size);
168 		d->dma.d0 = BIT(9) | RX_DMA_D0_CMD_DMA_IT;
169 		*_d = *d;
170 	}
171 
172 	wil_dbg_misc(wil, "pmc_alloc: allocated successfully\n");
173 
174 	pmc_cmd.op = WMI_PMC_ALLOCATE;
175 	pmc_cmd.ring_size = cpu_to_le16(pmc->num_descriptors);
176 	pmc_cmd.mem_base = cpu_to_le64(pmc->pring_pa);
177 
178 	wil_dbg_misc(wil, "pmc_alloc: send WMI_PMC_CMD with ALLOCATE op\n");
179 	pmc->last_cmd_status = wmi_send(wil,
180 					WMI_PMC_CMDID,
181 					vif->mid,
182 					&pmc_cmd,
183 					sizeof(pmc_cmd));
184 	if (pmc->last_cmd_status) {
185 		wil_err(wil,
186 			"WMI_PMC_CMD with ALLOCATE op failed with status %d",
187 			pmc->last_cmd_status);
188 		goto release_pmc_skbs;
189 	}
190 
191 	mutex_unlock(&pmc->lock);
192 
193 	return;
194 
195 release_pmc_skbs:
196 	wil_err(wil, "exit on error: Releasing skbs...\n");
197 	for (i = 0; i < num_descriptors && pmc->descriptors[i].va; i++) {
198 		dma_free_coherent(dev,
199 				  descriptor_size,
200 				  pmc->descriptors[i].va,
201 				  pmc->descriptors[i].pa);
202 
203 		pmc->descriptors[i].va = NULL;
204 	}
205 	wil_err(wil, "exit on error: Releasing pring...\n");
206 
207 	dma_free_coherent(dev,
208 			  sizeof(struct vring_tx_desc) * num_descriptors,
209 			  pmc->pring_va,
210 			  pmc->pring_pa);
211 
212 	pmc->pring_va = NULL;
213 
214 release_pmc_skb_list:
215 	wil_err(wil, "exit on error: Releasing descriptors info list...\n");
216 	kfree(pmc->descriptors);
217 	pmc->descriptors = NULL;
218 
219 no_release_err:
220 	pmc->last_cmd_status = last_cmd_err;
221 	mutex_unlock(&pmc->lock);
222 }
223 
224 /**
225  * Traverse the p-ring and release all buffers.
226  * At the end release the p-ring memory
227  */
228 void wil_pmc_free(struct wil6210_priv *wil, int send_pmc_cmd)
229 {
230 	struct pmc_ctx *pmc = &wil->pmc;
231 	struct device *dev = wil_to_dev(wil);
232 	struct wil6210_vif *vif = ndev_to_vif(wil->main_ndev);
233 	struct wmi_pmc_cmd pmc_cmd = {0};
234 
235 	mutex_lock(&pmc->lock);
236 
237 	pmc->last_cmd_status = 0;
238 
239 	if (!wil_is_pmc_allocated(pmc)) {
240 		wil_dbg_misc(wil,
241 			     "pmc_free: Error, can't free - not allocated\n");
242 		pmc->last_cmd_status = -EPERM;
243 		mutex_unlock(&pmc->lock);
244 		return;
245 	}
246 
247 	if (send_pmc_cmd) {
248 		wil_dbg_misc(wil, "send WMI_PMC_CMD with RELEASE op\n");
249 		pmc_cmd.op = WMI_PMC_RELEASE;
250 		pmc->last_cmd_status =
251 				wmi_send(wil, WMI_PMC_CMDID, vif->mid,
252 					 &pmc_cmd, sizeof(pmc_cmd));
253 		if (pmc->last_cmd_status) {
254 			wil_err(wil,
255 				"WMI_PMC_CMD with RELEASE op failed, status %d",
256 				pmc->last_cmd_status);
257 			/* There's nothing we can do with this error.
258 			 * Normally, it should never occur.
259 			 * Continue to freeing all memory allocated for pmc.
260 			 */
261 		}
262 	}
263 
264 	if (pmc->pring_va) {
265 		size_t buf_size = sizeof(struct vring_tx_desc) *
266 				  pmc->num_descriptors;
267 
268 		wil_dbg_misc(wil, "pmc_free: free pring va %p\n",
269 			     pmc->pring_va);
270 		dma_free_coherent(dev, buf_size, pmc->pring_va, pmc->pring_pa);
271 
272 		pmc->pring_va = NULL;
273 	} else {
274 		pmc->last_cmd_status = -ENOENT;
275 	}
276 
277 	if (pmc->descriptors) {
278 		int i;
279 
280 		for (i = 0;
281 		     i < pmc->num_descriptors && pmc->descriptors[i].va; i++) {
282 			dma_free_coherent(dev,
283 					  pmc->descriptor_size,
284 					  pmc->descriptors[i].va,
285 					  pmc->descriptors[i].pa);
286 			pmc->descriptors[i].va = NULL;
287 		}
288 		wil_dbg_misc(wil, "pmc_free: free descriptor info %d/%d\n", i,
289 			     pmc->num_descriptors);
290 		wil_dbg_misc(wil,
291 			     "pmc_free: free pmc descriptors info list %p\n",
292 			     pmc->descriptors);
293 		kfree(pmc->descriptors);
294 		pmc->descriptors = NULL;
295 	} else {
296 		pmc->last_cmd_status = -ENOENT;
297 	}
298 
299 	mutex_unlock(&pmc->lock);
300 }
301 
302 /**
303  * Status of the last operation requested via debugfs: alloc/free/read.
304  * 0 - success or negative errno
305  */
306 int wil_pmc_last_cmd_status(struct wil6210_priv *wil)
307 {
308 	wil_dbg_misc(wil, "pmc_last_cmd_status: status %d\n",
309 		     wil->pmc.last_cmd_status);
310 
311 	return wil->pmc.last_cmd_status;
312 }
313 
314 /**
315  * Read from required position up to the end of current descriptor,
316  * depends on descriptor size configured during alloc request.
317  */
318 ssize_t wil_pmc_read(struct file *filp, char __user *buf, size_t count,
319 		     loff_t *f_pos)
320 {
321 	struct wil6210_priv *wil = filp->private_data;
322 	struct pmc_ctx *pmc = &wil->pmc;
323 	size_t retval = 0;
324 	unsigned long long idx;
325 	loff_t offset;
326 	size_t pmc_size;
327 
328 	mutex_lock(&pmc->lock);
329 
330 	if (!wil_is_pmc_allocated(pmc)) {
331 		wil_err(wil, "error, pmc is not allocated!\n");
332 		pmc->last_cmd_status = -EPERM;
333 		mutex_unlock(&pmc->lock);
334 		return -EPERM;
335 	}
336 
337 	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
338 
339 	wil_dbg_misc(wil,
340 		     "pmc_read: size %u, pos %lld\n",
341 		     (u32)count, *f_pos);
342 
343 	pmc->last_cmd_status = 0;
344 
345 	idx = *f_pos;
346 	do_div(idx, pmc->descriptor_size);
347 	offset = *f_pos - (idx * pmc->descriptor_size);
348 
349 	if (*f_pos >= pmc_size) {
350 		wil_dbg_misc(wil,
351 			     "pmc_read: reached end of pmc buf: %lld >= %u\n",
352 			     *f_pos, (u32)pmc_size);
353 		pmc->last_cmd_status = -ERANGE;
354 		goto out;
355 	}
356 
357 	wil_dbg_misc(wil,
358 		     "pmc_read: read from pos %lld (descriptor %llu, offset %llu) %zu bytes\n",
359 		     *f_pos, idx, offset, count);
360 
361 	/* if no errors, return the copied byte count */
362 	retval = simple_read_from_buffer(buf,
363 					 count,
364 					 &offset,
365 					 pmc->descriptors[idx].va,
366 					 pmc->descriptor_size);
367 	*f_pos += retval;
368 out:
369 	mutex_unlock(&pmc->lock);
370 
371 	return retval;
372 }
373 
374 loff_t wil_pmc_llseek(struct file *filp, loff_t off, int whence)
375 {
376 	loff_t newpos;
377 	struct wil6210_priv *wil = filp->private_data;
378 	struct pmc_ctx *pmc = &wil->pmc;
379 	size_t pmc_size;
380 
381 	mutex_lock(&pmc->lock);
382 
383 	if (!wil_is_pmc_allocated(pmc)) {
384 		wil_err(wil, "error, pmc is not allocated!\n");
385 		pmc->last_cmd_status = -EPERM;
386 		mutex_unlock(&pmc->lock);
387 		return -EPERM;
388 	}
389 
390 	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
391 
392 	switch (whence) {
393 	case 0: /* SEEK_SET */
394 		newpos = off;
395 		break;
396 
397 	case 1: /* SEEK_CUR */
398 		newpos = filp->f_pos + off;
399 		break;
400 
401 	case 2: /* SEEK_END */
402 		newpos = pmc_size;
403 		break;
404 
405 	default: /* can't happen */
406 		newpos = -EINVAL;
407 		goto out;
408 	}
409 
410 	if (newpos < 0) {
411 		newpos = -EINVAL;
412 		goto out;
413 	}
414 	if (newpos > pmc_size)
415 		newpos = pmc_size;
416 
417 	filp->f_pos = newpos;
418 
419 out:
420 	mutex_unlock(&pmc->lock);
421 
422 	return newpos;
423 }
424 
425 int wil_pmcring_read(struct seq_file *s, void *data)
426 {
427 	struct wil6210_priv *wil = s->private;
428 	struct pmc_ctx *pmc = &wil->pmc;
429 	size_t pmc_ring_size =
430 		sizeof(struct vring_rx_desc) * pmc->num_descriptors;
431 
432 	mutex_lock(&pmc->lock);
433 
434 	if (!wil_is_pmc_allocated(pmc)) {
435 		wil_err(wil, "error, pmc is not allocated!\n");
436 		pmc->last_cmd_status = -EPERM;
437 		mutex_unlock(&pmc->lock);
438 		return -EPERM;
439 	}
440 
441 	wil_dbg_misc(wil, "pmcring_read: size %zu\n", pmc_ring_size);
442 
443 	seq_write(s, pmc->pring_va, pmc_ring_size);
444 
445 	mutex_unlock(&pmc->lock);
446 
447 	return 0;
448 }
449