1 /*
2  * Driver for Marvell NETA network controller Buffer Manager.
3  *
4  * Copyright (C) 2015 Marvell
5  *
6  * Marcin Wojtas <mw@semihalf.com>
7  *
8  * This file is licensed under the terms of the GNU General Public
9  * License version 2. This program is licensed "as is" without any
10  * warranty of any kind, whether express or implied.
11  */
12 
13 #include <linux/clk.h>
14 #include <linux/genalloc.h>
15 #include <linux/io.h>
16 #include <linux/kernel.h>
17 #include <linux/mbus.h>
18 #include <linux/module.h>
19 #include <linux/netdevice.h>
20 #include <linux/of.h>
21 #include <linux/platform_device.h>
22 #include <linux/skbuff.h>
23 #include <net/hwbm.h>
24 #include "mvneta_bm.h"
25 
26 #define MVNETA_BM_DRIVER_NAME "mvneta_bm"
27 #define MVNETA_BM_DRIVER_VERSION "1.0"
28 
29 static void mvneta_bm_write(struct mvneta_bm *priv, u32 offset, u32 data)
30 {
31 	writel(data, priv->reg_base + offset);
32 }
33 
34 static u32 mvneta_bm_read(struct mvneta_bm *priv, u32 offset)
35 {
36 	return readl(priv->reg_base + offset);
37 }
38 
39 static void mvneta_bm_pool_enable(struct mvneta_bm *priv, int pool_id)
40 {
41 	u32 val;
42 
43 	val = mvneta_bm_read(priv, MVNETA_BM_POOL_BASE_REG(pool_id));
44 	val |= MVNETA_BM_POOL_ENABLE_MASK;
45 	mvneta_bm_write(priv, MVNETA_BM_POOL_BASE_REG(pool_id), val);
46 
47 	/* Clear BM cause register */
48 	mvneta_bm_write(priv, MVNETA_BM_INTR_CAUSE_REG, 0);
49 }
50 
51 static void mvneta_bm_pool_disable(struct mvneta_bm *priv, int pool_id)
52 {
53 	u32 val;
54 
55 	val = mvneta_bm_read(priv, MVNETA_BM_POOL_BASE_REG(pool_id));
56 	val &= ~MVNETA_BM_POOL_ENABLE_MASK;
57 	mvneta_bm_write(priv, MVNETA_BM_POOL_BASE_REG(pool_id), val);
58 }
59 
60 static inline void mvneta_bm_config_set(struct mvneta_bm *priv, u32 mask)
61 {
62 	u32 val;
63 
64 	val = mvneta_bm_read(priv, MVNETA_BM_CONFIG_REG);
65 	val |= mask;
66 	mvneta_bm_write(priv, MVNETA_BM_CONFIG_REG, val);
67 }
68 
69 static inline void mvneta_bm_config_clear(struct mvneta_bm *priv, u32 mask)
70 {
71 	u32 val;
72 
73 	val = mvneta_bm_read(priv, MVNETA_BM_CONFIG_REG);
74 	val &= ~mask;
75 	mvneta_bm_write(priv, MVNETA_BM_CONFIG_REG, val);
76 }
77 
78 static void mvneta_bm_pool_target_set(struct mvneta_bm *priv, int pool_id,
79 				      u8 target_id, u8 attr)
80 {
81 	u32 val;
82 
83 	val = mvneta_bm_read(priv, MVNETA_BM_XBAR_POOL_REG(pool_id));
84 	val &= ~MVNETA_BM_TARGET_ID_MASK(pool_id);
85 	val &= ~MVNETA_BM_XBAR_ATTR_MASK(pool_id);
86 	val |= MVNETA_BM_TARGET_ID_VAL(pool_id, target_id);
87 	val |= MVNETA_BM_XBAR_ATTR_VAL(pool_id, attr);
88 
89 	mvneta_bm_write(priv, MVNETA_BM_XBAR_POOL_REG(pool_id), val);
90 }
91 
92 int mvneta_bm_construct(struct hwbm_pool *hwbm_pool, void *buf)
93 {
94 	struct mvneta_bm_pool *bm_pool =
95 		(struct mvneta_bm_pool *)hwbm_pool->priv;
96 	struct mvneta_bm *priv = bm_pool->priv;
97 	dma_addr_t phys_addr;
98 
99 	/* In order to update buf_cookie field of RX descriptor properly,
100 	 * BM hardware expects buf virtual address to be placed in the
101 	 * first four bytes of mapped buffer.
102 	 */
103 	*(u32 *)buf = (u32)buf;
104 	phys_addr = dma_map_single(&priv->pdev->dev, buf, bm_pool->buf_size,
105 				   DMA_FROM_DEVICE);
106 	if (unlikely(dma_mapping_error(&priv->pdev->dev, phys_addr)))
107 		return -ENOMEM;
108 
109 	mvneta_bm_pool_put_bp(priv, bm_pool, phys_addr);
110 	return 0;
111 }
112 EXPORT_SYMBOL_GPL(mvneta_bm_construct);
113 
114 /* Create pool */
115 static int mvneta_bm_pool_create(struct mvneta_bm *priv,
116 				 struct mvneta_bm_pool *bm_pool)
117 {
118 	struct platform_device *pdev = priv->pdev;
119 	u8 target_id, attr;
120 	int size_bytes, err;
121 	size_bytes = sizeof(u32) * bm_pool->hwbm_pool.size;
122 	bm_pool->virt_addr = dma_alloc_coherent(&pdev->dev, size_bytes,
123 						&bm_pool->phys_addr,
124 						GFP_KERNEL);
125 	if (!bm_pool->virt_addr)
126 		return -ENOMEM;
127 
128 	if (!IS_ALIGNED((u32)bm_pool->virt_addr, MVNETA_BM_POOL_PTR_ALIGN)) {
129 		dma_free_coherent(&pdev->dev, size_bytes, bm_pool->virt_addr,
130 				  bm_pool->phys_addr);
131 		dev_err(&pdev->dev, "BM pool %d is not %d bytes aligned\n",
132 			bm_pool->id, MVNETA_BM_POOL_PTR_ALIGN);
133 		return -ENOMEM;
134 	}
135 
136 	err = mvebu_mbus_get_dram_win_info(bm_pool->phys_addr, &target_id,
137 					   &attr);
138 	if (err < 0) {
139 		dma_free_coherent(&pdev->dev, size_bytes, bm_pool->virt_addr,
140 				  bm_pool->phys_addr);
141 		return err;
142 	}
143 
144 	/* Set pool address */
145 	mvneta_bm_write(priv, MVNETA_BM_POOL_BASE_REG(bm_pool->id),
146 			bm_pool->phys_addr);
147 
148 	mvneta_bm_pool_target_set(priv, bm_pool->id, target_id,  attr);
149 	mvneta_bm_pool_enable(priv, bm_pool->id);
150 
151 	return 0;
152 }
153 
154 /* Notify the driver that BM pool is being used as specific type and return the
155  * pool pointer on success
156  */
157 struct mvneta_bm_pool *mvneta_bm_pool_use(struct mvneta_bm *priv, u8 pool_id,
158 					  enum mvneta_bm_type type, u8 port_id,
159 					  int pkt_size)
160 {
161 	struct mvneta_bm_pool *new_pool = &priv->bm_pools[pool_id];
162 	int num, err;
163 
164 	if (new_pool->type == MVNETA_BM_LONG &&
165 	    new_pool->port_map != 1 << port_id) {
166 		dev_err(&priv->pdev->dev,
167 			"long pool cannot be shared by the ports\n");
168 		return NULL;
169 	}
170 
171 	if (new_pool->type == MVNETA_BM_SHORT && new_pool->type != type) {
172 		dev_err(&priv->pdev->dev,
173 			"mixing pools' types between the ports is forbidden\n");
174 		return NULL;
175 	}
176 
177 	if (new_pool->pkt_size == 0 || type != MVNETA_BM_SHORT)
178 		new_pool->pkt_size = pkt_size;
179 
180 	/* Allocate buffers in case BM pool hasn't been used yet */
181 	if (new_pool->type == MVNETA_BM_FREE) {
182 		struct hwbm_pool *hwbm_pool = &new_pool->hwbm_pool;
183 
184 		new_pool->priv = priv;
185 		new_pool->type = type;
186 		new_pool->buf_size = MVNETA_RX_BUF_SIZE(new_pool->pkt_size);
187 		hwbm_pool->frag_size =
188 			SKB_DATA_ALIGN(MVNETA_RX_BUF_SIZE(new_pool->pkt_size)) +
189 			SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
190 		hwbm_pool->construct = mvneta_bm_construct;
191 		hwbm_pool->priv = new_pool;
192 		spin_lock_init(&hwbm_pool->lock);
193 
194 		/* Create new pool */
195 		err = mvneta_bm_pool_create(priv, new_pool);
196 		if (err) {
197 			dev_err(&priv->pdev->dev, "fail to create pool %d\n",
198 				new_pool->id);
199 			return NULL;
200 		}
201 
202 		/* Allocate buffers for this pool */
203 		num = hwbm_pool_add(hwbm_pool, hwbm_pool->size, GFP_ATOMIC);
204 		if (num != hwbm_pool->size) {
205 			WARN(1, "pool %d: %d of %d allocated\n",
206 			     new_pool->id, num, hwbm_pool->size);
207 			return NULL;
208 		}
209 	}
210 
211 	return new_pool;
212 }
213 EXPORT_SYMBOL_GPL(mvneta_bm_pool_use);
214 
215 /* Free all buffers from the pool */
216 void mvneta_bm_bufs_free(struct mvneta_bm *priv, struct mvneta_bm_pool *bm_pool,
217 			 u8 port_map)
218 {
219 	int i;
220 
221 	bm_pool->port_map &= ~port_map;
222 	if (bm_pool->port_map)
223 		return;
224 
225 	mvneta_bm_config_set(priv, MVNETA_BM_EMPTY_LIMIT_MASK);
226 
227 	for (i = 0; i < bm_pool->hwbm_pool.buf_num; i++) {
228 		dma_addr_t buf_phys_addr;
229 		u32 *vaddr;
230 
231 		/* Get buffer physical address (indirect access) */
232 		buf_phys_addr = mvneta_bm_pool_get_bp(priv, bm_pool);
233 
234 		/* Work-around to the problems when destroying the pool,
235 		 * when it occurs that a read access to BPPI returns 0.
236 		 */
237 		if (buf_phys_addr == 0)
238 			continue;
239 
240 		vaddr = phys_to_virt(buf_phys_addr);
241 		if (!vaddr)
242 			break;
243 
244 		dma_unmap_single(&priv->pdev->dev, buf_phys_addr,
245 				 bm_pool->buf_size, DMA_FROM_DEVICE);
246 		hwbm_buf_free(&bm_pool->hwbm_pool, vaddr);
247 	}
248 
249 	mvneta_bm_config_clear(priv, MVNETA_BM_EMPTY_LIMIT_MASK);
250 
251 	/* Update BM driver with number of buffers removed from pool */
252 	bm_pool->hwbm_pool.buf_num -= i;
253 }
254 EXPORT_SYMBOL_GPL(mvneta_bm_bufs_free);
255 
256 /* Cleanup pool */
257 void mvneta_bm_pool_destroy(struct mvneta_bm *priv,
258 			    struct mvneta_bm_pool *bm_pool, u8 port_map)
259 {
260 	struct hwbm_pool *hwbm_pool = &bm_pool->hwbm_pool;
261 	bm_pool->port_map &= ~port_map;
262 	if (bm_pool->port_map)
263 		return;
264 
265 	bm_pool->type = MVNETA_BM_FREE;
266 
267 	mvneta_bm_bufs_free(priv, bm_pool, port_map);
268 	if (hwbm_pool->buf_num)
269 		WARN(1, "cannot free all buffers in pool %d\n", bm_pool->id);
270 
271 	if (bm_pool->virt_addr) {
272 		dma_free_coherent(&priv->pdev->dev,
273 				  sizeof(u32) * hwbm_pool->size,
274 				  bm_pool->virt_addr, bm_pool->phys_addr);
275 		bm_pool->virt_addr = NULL;
276 	}
277 
278 	mvneta_bm_pool_disable(priv, bm_pool->id);
279 }
280 EXPORT_SYMBOL_GPL(mvneta_bm_pool_destroy);
281 
282 static void mvneta_bm_pools_init(struct mvneta_bm *priv)
283 {
284 	struct device_node *dn = priv->pdev->dev.of_node;
285 	struct mvneta_bm_pool *bm_pool;
286 	char prop[15];
287 	u32 size;
288 	int i;
289 
290 	/* Activate BM unit */
291 	mvneta_bm_write(priv, MVNETA_BM_COMMAND_REG, MVNETA_BM_START_MASK);
292 
293 	/* Create all pools with maximum size */
294 	for (i = 0; i < MVNETA_BM_POOLS_NUM; i++) {
295 		bm_pool = &priv->bm_pools[i];
296 		bm_pool->id = i;
297 		bm_pool->type = MVNETA_BM_FREE;
298 
299 		/* Reset read pointer */
300 		mvneta_bm_write(priv, MVNETA_BM_POOL_READ_PTR_REG(i), 0);
301 
302 		/* Reset write pointer */
303 		mvneta_bm_write(priv, MVNETA_BM_POOL_WRITE_PTR_REG(i), 0);
304 
305 		/* Configure pool size according to DT or use default value */
306 		sprintf(prop, "pool%d,capacity", i);
307 		if (of_property_read_u32(dn, prop, &size)) {
308 			size = MVNETA_BM_POOL_CAP_DEF;
309 		} else if (size > MVNETA_BM_POOL_CAP_MAX) {
310 			dev_warn(&priv->pdev->dev,
311 				 "Illegal pool %d capacity %d, set to %d\n",
312 				 i, size, MVNETA_BM_POOL_CAP_MAX);
313 			size = MVNETA_BM_POOL_CAP_MAX;
314 		} else if (size < MVNETA_BM_POOL_CAP_MIN) {
315 			dev_warn(&priv->pdev->dev,
316 				 "Illegal pool %d capacity %d, set to %d\n",
317 				 i, size, MVNETA_BM_POOL_CAP_MIN);
318 			size = MVNETA_BM_POOL_CAP_MIN;
319 		} else if (!IS_ALIGNED(size, MVNETA_BM_POOL_CAP_ALIGN)) {
320 			dev_warn(&priv->pdev->dev,
321 				 "Illegal pool %d capacity %d, round to %d\n",
322 				 i, size, ALIGN(size,
323 				 MVNETA_BM_POOL_CAP_ALIGN));
324 			size = ALIGN(size, MVNETA_BM_POOL_CAP_ALIGN);
325 		}
326 		bm_pool->hwbm_pool.size = size;
327 
328 		mvneta_bm_write(priv, MVNETA_BM_POOL_SIZE_REG(i),
329 				bm_pool->hwbm_pool.size);
330 
331 		/* Obtain custom pkt_size from DT */
332 		sprintf(prop, "pool%d,pkt-size", i);
333 		if (of_property_read_u32(dn, prop, &bm_pool->pkt_size))
334 			bm_pool->pkt_size = 0;
335 	}
336 }
337 
338 static void mvneta_bm_default_set(struct mvneta_bm *priv)
339 {
340 	u32 val;
341 
342 	/* Mask BM all interrupts */
343 	mvneta_bm_write(priv, MVNETA_BM_INTR_MASK_REG, 0);
344 
345 	/* Clear BM cause register */
346 	mvneta_bm_write(priv, MVNETA_BM_INTR_CAUSE_REG, 0);
347 
348 	/* Set BM configuration register */
349 	val = mvneta_bm_read(priv, MVNETA_BM_CONFIG_REG);
350 
351 	/* Reduce MaxInBurstSize from 32 BPs to 16 BPs */
352 	val &= ~MVNETA_BM_MAX_IN_BURST_SIZE_MASK;
353 	val |= MVNETA_BM_MAX_IN_BURST_SIZE_16BP;
354 	mvneta_bm_write(priv, MVNETA_BM_CONFIG_REG, val);
355 }
356 
357 static int mvneta_bm_init(struct mvneta_bm *priv)
358 {
359 	mvneta_bm_default_set(priv);
360 
361 	/* Allocate and initialize BM pools structures */
362 	priv->bm_pools = devm_kcalloc(&priv->pdev->dev, MVNETA_BM_POOLS_NUM,
363 				      sizeof(struct mvneta_bm_pool),
364 				      GFP_KERNEL);
365 	if (!priv->bm_pools)
366 		return -ENOMEM;
367 
368 	mvneta_bm_pools_init(priv);
369 
370 	return 0;
371 }
372 
373 static int mvneta_bm_get_sram(struct device_node *dn,
374 			      struct mvneta_bm *priv)
375 {
376 	priv->bppi_pool = of_gen_pool_get(dn, "internal-mem", 0);
377 	if (!priv->bppi_pool)
378 		return -ENOMEM;
379 
380 	priv->bppi_virt_addr = gen_pool_dma_alloc(priv->bppi_pool,
381 						  MVNETA_BM_BPPI_SIZE,
382 						  &priv->bppi_phys_addr);
383 	if (!priv->bppi_virt_addr)
384 		return -ENOMEM;
385 
386 	return 0;
387 }
388 
389 static void mvneta_bm_put_sram(struct mvneta_bm *priv)
390 {
391 	gen_pool_free(priv->bppi_pool, priv->bppi_phys_addr,
392 		      MVNETA_BM_BPPI_SIZE);
393 }
394 
395 static int mvneta_bm_probe(struct platform_device *pdev)
396 {
397 	struct device_node *dn = pdev->dev.of_node;
398 	struct mvneta_bm *priv;
399 	struct resource *res;
400 	int err;
401 
402 	priv = devm_kzalloc(&pdev->dev, sizeof(struct mvneta_bm), GFP_KERNEL);
403 	if (!priv)
404 		return -ENOMEM;
405 
406 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
407 	priv->reg_base = devm_ioremap_resource(&pdev->dev, res);
408 	if (IS_ERR(priv->reg_base))
409 		return PTR_ERR(priv->reg_base);
410 
411 	priv->clk = devm_clk_get(&pdev->dev, NULL);
412 	if (IS_ERR(priv->clk))
413 		return PTR_ERR(priv->clk);
414 	err = clk_prepare_enable(priv->clk);
415 	if (err < 0)
416 		return err;
417 
418 	err = mvneta_bm_get_sram(dn, priv);
419 	if (err < 0) {
420 		dev_err(&pdev->dev, "failed to allocate internal memory\n");
421 		goto err_clk;
422 	}
423 
424 	priv->pdev = pdev;
425 
426 	/* Initialize buffer manager internals */
427 	err = mvneta_bm_init(priv);
428 	if (err < 0) {
429 		dev_err(&pdev->dev, "failed to initialize controller\n");
430 		goto err_sram;
431 	}
432 
433 	dn->data = priv;
434 	platform_set_drvdata(pdev, priv);
435 
436 	dev_info(&pdev->dev, "Buffer Manager for network controller enabled\n");
437 
438 	return 0;
439 
440 err_sram:
441 	mvneta_bm_put_sram(priv);
442 err_clk:
443 	clk_disable_unprepare(priv->clk);
444 	return err;
445 }
446 
447 static int mvneta_bm_remove(struct platform_device *pdev)
448 {
449 	struct mvneta_bm *priv = platform_get_drvdata(pdev);
450 	u8 all_ports_map = 0xff;
451 	int i = 0;
452 
453 	for (i = 0; i < MVNETA_BM_POOLS_NUM; i++) {
454 		struct mvneta_bm_pool *bm_pool = &priv->bm_pools[i];
455 
456 		mvneta_bm_pool_destroy(priv, bm_pool, all_ports_map);
457 	}
458 
459 	mvneta_bm_put_sram(priv);
460 
461 	/* Dectivate BM unit */
462 	mvneta_bm_write(priv, MVNETA_BM_COMMAND_REG, MVNETA_BM_STOP_MASK);
463 
464 	clk_disable_unprepare(priv->clk);
465 
466 	return 0;
467 }
468 
469 static const struct of_device_id mvneta_bm_match[] = {
470 	{ .compatible = "marvell,armada-380-neta-bm" },
471 	{ }
472 };
473 MODULE_DEVICE_TABLE(of, mvneta_bm_match);
474 
475 static struct platform_driver mvneta_bm_driver = {
476 	.probe = mvneta_bm_probe,
477 	.remove = mvneta_bm_remove,
478 	.driver = {
479 		.name = MVNETA_BM_DRIVER_NAME,
480 		.of_match_table = mvneta_bm_match,
481 	},
482 };
483 
484 module_platform_driver(mvneta_bm_driver);
485 
486 MODULE_DESCRIPTION("Marvell NETA Buffer Manager Driver - www.marvell.com");
487 MODULE_AUTHOR("Marcin Wojtas <mw@semihalf.com>");
488 MODULE_LICENSE("GPL v2");
489