xref: /openbmc/linux/drivers/net/ethernet/google/gve/gve.h (revision fb574682)
1 /* SPDX-License-Identifier: (GPL-2.0 OR MIT)
2  * Google virtual Ethernet (gve) driver
3  *
4  * Copyright (C) 2015-2019 Google, Inc.
5  */
6 
7 #ifndef _GVE_H_
8 #define _GVE_H_
9 
10 #include <linux/dma-mapping.h>
11 #include <linux/netdevice.h>
12 #include <linux/pci.h>
13 #include <linux/u64_stats_sync.h>
14 #include "gve_desc.h"
15 
16 #ifndef PCI_VENDOR_ID_GOOGLE
17 #define PCI_VENDOR_ID_GOOGLE	0x1ae0
18 #endif
19 
20 #define PCI_DEV_ID_GVNIC	0x0042
21 
22 #define GVE_REGISTER_BAR	0
23 #define GVE_DOORBELL_BAR	2
24 
25 /* Driver can alloc up to 2 segments for the header and 2 for the payload. */
26 #define GVE_TX_MAX_IOVEC	4
27 /* 1 for management, 1 for rx, 1 for tx */
28 #define GVE_MIN_MSIX 3
29 
30 /* Each slot in the desc ring has a 1:1 mapping to a slot in the data ring */
31 struct gve_rx_desc_queue {
32 	struct gve_rx_desc *desc_ring; /* the descriptor ring */
33 	dma_addr_t bus; /* the bus for the desc_ring */
34 	u8 seqno; /* the next expected seqno for this desc*/
35 };
36 
37 /* The page info for a single slot in the RX data queue */
38 struct gve_rx_slot_page_info {
39 	struct page *page;
40 	void *page_address;
41 	u32 page_offset; /* offset to write to in page */
42 };
43 
44 /* A list of pages registered with the device during setup and used by a queue
45  * as buffers
46  */
47 struct gve_queue_page_list {
48 	u32 id; /* unique id */
49 	u32 num_entries;
50 	struct page **pages; /* list of num_entries pages */
51 	dma_addr_t *page_buses; /* the dma addrs of the pages */
52 };
53 
54 /* Each slot in the data ring has a 1:1 mapping to a slot in the desc ring */
55 struct gve_rx_data_queue {
56 	struct gve_rx_data_slot *data_ring; /* read by NIC */
57 	dma_addr_t data_bus; /* dma mapping of the slots */
58 	struct gve_rx_slot_page_info *page_info; /* page info of the buffers */
59 	struct gve_queue_page_list *qpl; /* qpl assigned to this queue */
60 };
61 
62 struct gve_priv;
63 
64 /* An RX ring that contains a power-of-two sized desc and data ring. */
65 struct gve_rx_ring {
66 	struct gve_priv *gve;
67 	struct gve_rx_desc_queue desc;
68 	struct gve_rx_data_queue data;
69 	u64 rbytes; /* free-running bytes received */
70 	u64 rpackets; /* free-running packets received */
71 	u32 cnt; /* free-running total number of completed packets */
72 	u32 fill_cnt; /* free-running total number of descs and buffs posted */
73 	u32 mask; /* masks the cnt and fill_cnt to the size of the ring */
74 	u32 q_num; /* queue index */
75 	u32 ntfy_id; /* notification block index */
76 	struct gve_queue_resources *q_resources; /* head and tail pointer idx */
77 	dma_addr_t q_resources_bus; /* dma address for the queue resources */
78 	struct u64_stats_sync statss; /* sync stats for 32bit archs */
79 };
80 
81 /* A TX desc ring entry */
82 union gve_tx_desc {
83 	struct gve_tx_pkt_desc pkt; /* first desc for a packet */
84 	struct gve_tx_seg_desc seg; /* subsequent descs for a packet */
85 };
86 
87 /* Tracks the memory in the fifo occupied by a segment of a packet */
88 struct gve_tx_iovec {
89 	u32 iov_offset; /* offset into this segment */
90 	u32 iov_len; /* length */
91 	u32 iov_padding; /* padding associated with this segment */
92 };
93 
94 /* Tracks the memory in the fifo occupied by the skb. Mapped 1:1 to a desc
95  * ring entry but only used for a pkt_desc not a seg_desc
96  */
97 struct gve_tx_buffer_state {
98 	struct sk_buff *skb; /* skb for this pkt */
99 	struct gve_tx_iovec iov[GVE_TX_MAX_IOVEC]; /* segments of this pkt */
100 };
101 
102 /* A TX buffer - each queue has one */
103 struct gve_tx_fifo {
104 	void *base; /* address of base of FIFO */
105 	u32 size; /* total size */
106 	atomic_t available; /* how much space is still available */
107 	u32 head; /* offset to write at */
108 	struct gve_queue_page_list *qpl; /* QPL mapped into this FIFO */
109 };
110 
111 /* A TX ring that contains a power-of-two sized desc ring and a FIFO buffer */
112 struct gve_tx_ring {
113 	/* Cacheline 0 -- Accessed & dirtied during transmit */
114 	struct gve_tx_fifo tx_fifo;
115 	u32 req; /* driver tracked head pointer */
116 	u32 done; /* driver tracked tail pointer */
117 
118 	/* Cacheline 1 -- Accessed & dirtied during gve_clean_tx_done */
119 	__be32 last_nic_done ____cacheline_aligned; /* NIC tail pointer */
120 	u64 pkt_done; /* free-running - total packets completed */
121 	u64 bytes_done; /* free-running - total bytes completed */
122 
123 	/* Cacheline 2 -- Read-mostly fields */
124 	union gve_tx_desc *desc ____cacheline_aligned;
125 	struct gve_tx_buffer_state *info; /* Maps 1:1 to a desc */
126 	struct netdev_queue *netdev_txq;
127 	struct gve_queue_resources *q_resources; /* head and tail pointer idx */
128 	u32 mask; /* masks req and done down to queue size */
129 
130 	/* Slow-path fields */
131 	u32 q_num ____cacheline_aligned; /* queue idx */
132 	u32 stop_queue; /* count of queue stops */
133 	u32 wake_queue; /* count of queue wakes */
134 	u32 ntfy_id; /* notification block index */
135 	dma_addr_t bus; /* dma address of the descr ring */
136 	dma_addr_t q_resources_bus; /* dma address of the queue resources */
137 	struct u64_stats_sync statss; /* sync stats for 32bit archs */
138 } ____cacheline_aligned;
139 
140 /* Wraps the info for one irq including the napi struct and the queues
141  * associated with that irq.
142  */
143 struct gve_notify_block {
144 	__be32 irq_db_index; /* idx into Bar2 - set by device, must be 1st */
145 	char name[IFNAMSIZ + 16]; /* name registered with the kernel */
146 	struct napi_struct napi; /* kernel napi struct for this block */
147 	struct gve_priv *priv;
148 	struct gve_tx_ring *tx; /* tx rings on this block */
149 	struct gve_rx_ring *rx; /* rx rings on this block */
150 } ____cacheline_aligned;
151 
152 /* Tracks allowed and current queue settings */
153 struct gve_queue_config {
154 	u16 max_queues;
155 	u16 num_queues; /* current */
156 };
157 
158 /* Tracks the available and used qpl IDs */
159 struct gve_qpl_config {
160 	u32 qpl_map_size; /* map memory size */
161 	unsigned long *qpl_id_map; /* bitmap of used qpl ids */
162 };
163 
164 struct gve_priv {
165 	struct net_device *dev;
166 	struct gve_tx_ring *tx; /* array of tx_cfg.num_queues */
167 	struct gve_rx_ring *rx; /* array of rx_cfg.num_queues */
168 	struct gve_queue_page_list *qpls; /* array of num qpls */
169 	struct gve_notify_block *ntfy_blocks; /* array of num_ntfy_blks */
170 	dma_addr_t ntfy_block_bus;
171 	struct msix_entry *msix_vectors; /* array of num_ntfy_blks + 1 */
172 	char mgmt_msix_name[IFNAMSIZ + 16];
173 	u32 mgmt_msix_idx;
174 	__be32 *counter_array; /* array of num_event_counters */
175 	dma_addr_t counter_array_bus;
176 
177 	u16 num_event_counters;
178 	u16 tx_desc_cnt; /* num desc per ring */
179 	u16 rx_desc_cnt; /* num desc per ring */
180 	u16 tx_pages_per_qpl; /* tx buffer length */
181 	u16 rx_pages_per_qpl; /* rx buffer length */
182 	u64 max_registered_pages;
183 	u64 num_registered_pages; /* num pages registered with NIC */
184 	u32 rx_copybreak; /* copy packets smaller than this */
185 	u16 default_num_queues; /* default num queues to set up */
186 
187 	struct gve_queue_config tx_cfg;
188 	struct gve_queue_config rx_cfg;
189 	struct gve_qpl_config qpl_cfg; /* map used QPL ids */
190 	u32 num_ntfy_blks; /* spilt between TX and RX so must be even */
191 
192 	struct gve_registers __iomem *reg_bar0; /* see gve_register.h */
193 	__be32 __iomem *db_bar2; /* "array" of doorbells */
194 	u32 msg_enable;	/* level for netif* netdev print macros	*/
195 	struct pci_dev *pdev;
196 
197 	/* metrics */
198 	u32 tx_timeo_cnt;
199 
200 	/* Admin queue - see gve_adminq.h*/
201 	union gve_adminq_command *adminq;
202 	dma_addr_t adminq_bus_addr;
203 	u32 adminq_mask; /* masks prod_cnt to adminq size */
204 	u32 adminq_prod_cnt; /* free-running count of AQ cmds executed */
205 
206 	struct workqueue_struct *gve_wq;
207 	struct work_struct service_task;
208 	unsigned long service_task_flags;
209 	unsigned long state_flags;
210 };
211 
212 enum gve_service_task_flags {
213 	GVE_PRIV_FLAGS_DO_RESET			= BIT(1),
214 	GVE_PRIV_FLAGS_RESET_IN_PROGRESS	= BIT(2),
215 	GVE_PRIV_FLAGS_PROBE_IN_PROGRESS	= BIT(3),
216 };
217 
218 enum gve_state_flags {
219 	GVE_PRIV_FLAGS_ADMIN_QUEUE_OK		= BIT(1),
220 	GVE_PRIV_FLAGS_DEVICE_RESOURCES_OK	= BIT(2),
221 	GVE_PRIV_FLAGS_DEVICE_RINGS_OK		= BIT(3),
222 	GVE_PRIV_FLAGS_NAPI_ENABLED		= BIT(4),
223 };
224 
225 static inline bool gve_get_do_reset(struct gve_priv *priv)
226 {
227 	return test_bit(GVE_PRIV_FLAGS_DO_RESET, &priv->service_task_flags);
228 }
229 
230 static inline void gve_set_do_reset(struct gve_priv *priv)
231 {
232 	set_bit(GVE_PRIV_FLAGS_DO_RESET, &priv->service_task_flags);
233 }
234 
235 static inline void gve_clear_do_reset(struct gve_priv *priv)
236 {
237 	clear_bit(GVE_PRIV_FLAGS_DO_RESET, &priv->service_task_flags);
238 }
239 
240 static inline bool gve_get_reset_in_progress(struct gve_priv *priv)
241 {
242 	return test_bit(GVE_PRIV_FLAGS_RESET_IN_PROGRESS,
243 			&priv->service_task_flags);
244 }
245 
246 static inline void gve_set_reset_in_progress(struct gve_priv *priv)
247 {
248 	set_bit(GVE_PRIV_FLAGS_RESET_IN_PROGRESS, &priv->service_task_flags);
249 }
250 
251 static inline void gve_clear_reset_in_progress(struct gve_priv *priv)
252 {
253 	clear_bit(GVE_PRIV_FLAGS_RESET_IN_PROGRESS, &priv->service_task_flags);
254 }
255 
256 static inline bool gve_get_probe_in_progress(struct gve_priv *priv)
257 {
258 	return test_bit(GVE_PRIV_FLAGS_PROBE_IN_PROGRESS,
259 			&priv->service_task_flags);
260 }
261 
262 static inline void gve_set_probe_in_progress(struct gve_priv *priv)
263 {
264 	set_bit(GVE_PRIV_FLAGS_PROBE_IN_PROGRESS, &priv->service_task_flags);
265 }
266 
267 static inline void gve_clear_probe_in_progress(struct gve_priv *priv)
268 {
269 	clear_bit(GVE_PRIV_FLAGS_PROBE_IN_PROGRESS, &priv->service_task_flags);
270 }
271 
272 static inline bool gve_get_admin_queue_ok(struct gve_priv *priv)
273 {
274 	return test_bit(GVE_PRIV_FLAGS_ADMIN_QUEUE_OK, &priv->state_flags);
275 }
276 
277 static inline void gve_set_admin_queue_ok(struct gve_priv *priv)
278 {
279 	set_bit(GVE_PRIV_FLAGS_ADMIN_QUEUE_OK, &priv->state_flags);
280 }
281 
282 static inline void gve_clear_admin_queue_ok(struct gve_priv *priv)
283 {
284 	clear_bit(GVE_PRIV_FLAGS_ADMIN_QUEUE_OK, &priv->state_flags);
285 }
286 
287 static inline bool gve_get_device_resources_ok(struct gve_priv *priv)
288 {
289 	return test_bit(GVE_PRIV_FLAGS_DEVICE_RESOURCES_OK, &priv->state_flags);
290 }
291 
292 static inline void gve_set_device_resources_ok(struct gve_priv *priv)
293 {
294 	set_bit(GVE_PRIV_FLAGS_DEVICE_RESOURCES_OK, &priv->state_flags);
295 }
296 
297 static inline void gve_clear_device_resources_ok(struct gve_priv *priv)
298 {
299 	clear_bit(GVE_PRIV_FLAGS_DEVICE_RESOURCES_OK, &priv->state_flags);
300 }
301 
302 static inline bool gve_get_device_rings_ok(struct gve_priv *priv)
303 {
304 	return test_bit(GVE_PRIV_FLAGS_DEVICE_RINGS_OK, &priv->state_flags);
305 }
306 
307 static inline void gve_set_device_rings_ok(struct gve_priv *priv)
308 {
309 	set_bit(GVE_PRIV_FLAGS_DEVICE_RINGS_OK, &priv->state_flags);
310 }
311 
312 static inline void gve_clear_device_rings_ok(struct gve_priv *priv)
313 {
314 	clear_bit(GVE_PRIV_FLAGS_DEVICE_RINGS_OK, &priv->state_flags);
315 }
316 
317 static inline bool gve_get_napi_enabled(struct gve_priv *priv)
318 {
319 	return test_bit(GVE_PRIV_FLAGS_NAPI_ENABLED, &priv->state_flags);
320 }
321 
322 static inline void gve_set_napi_enabled(struct gve_priv *priv)
323 {
324 	set_bit(GVE_PRIV_FLAGS_NAPI_ENABLED, &priv->state_flags);
325 }
326 
327 static inline void gve_clear_napi_enabled(struct gve_priv *priv)
328 {
329 	clear_bit(GVE_PRIV_FLAGS_NAPI_ENABLED, &priv->state_flags);
330 }
331 
332 /* Returns the address of the ntfy_blocks irq doorbell
333  */
334 static inline __be32 __iomem *gve_irq_doorbell(struct gve_priv *priv,
335 					       struct gve_notify_block *block)
336 {
337 	return &priv->db_bar2[be32_to_cpu(block->irq_db_index)];
338 }
339 
340 /* Returns the index into ntfy_blocks of the given tx ring's block
341  */
342 static inline u32 gve_tx_idx_to_ntfy(struct gve_priv *priv, u32 queue_idx)
343 {
344 	return queue_idx;
345 }
346 
347 /* Returns the index into ntfy_blocks of the given rx ring's block
348  */
349 static inline u32 gve_rx_idx_to_ntfy(struct gve_priv *priv, u32 queue_idx)
350 {
351 	return (priv->num_ntfy_blks / 2) + queue_idx;
352 }
353 
354 /* Returns the number of tx queue page lists
355  */
356 static inline u32 gve_num_tx_qpls(struct gve_priv *priv)
357 {
358 	return priv->tx_cfg.num_queues;
359 }
360 
361 /* Returns the number of rx queue page lists
362  */
363 static inline u32 gve_num_rx_qpls(struct gve_priv *priv)
364 {
365 	return priv->rx_cfg.num_queues;
366 }
367 
368 /* Returns a pointer to the next available tx qpl in the list of qpls
369  */
370 static inline
371 struct gve_queue_page_list *gve_assign_tx_qpl(struct gve_priv *priv)
372 {
373 	int id = find_first_zero_bit(priv->qpl_cfg.qpl_id_map,
374 				     priv->qpl_cfg.qpl_map_size);
375 
376 	/* we are out of tx qpls */
377 	if (id >= gve_num_tx_qpls(priv))
378 		return NULL;
379 
380 	set_bit(id, priv->qpl_cfg.qpl_id_map);
381 	return &priv->qpls[id];
382 }
383 
384 /* Returns a pointer to the next available rx qpl in the list of qpls
385  */
386 static inline
387 struct gve_queue_page_list *gve_assign_rx_qpl(struct gve_priv *priv)
388 {
389 	int id = find_next_zero_bit(priv->qpl_cfg.qpl_id_map,
390 				    priv->qpl_cfg.qpl_map_size,
391 				    gve_num_tx_qpls(priv));
392 
393 	/* we are out of rx qpls */
394 	if (id == priv->qpl_cfg.qpl_map_size)
395 		return NULL;
396 
397 	set_bit(id, priv->qpl_cfg.qpl_id_map);
398 	return &priv->qpls[id];
399 }
400 
401 /* Unassigns the qpl with the given id
402  */
403 static inline void gve_unassign_qpl(struct gve_priv *priv, int id)
404 {
405 	clear_bit(id, priv->qpl_cfg.qpl_id_map);
406 }
407 
408 /* Returns the correct dma direction for tx and rx qpls
409  */
410 static inline enum dma_data_direction gve_qpl_dma_dir(struct gve_priv *priv,
411 						      int id)
412 {
413 	if (id < gve_num_tx_qpls(priv))
414 		return DMA_TO_DEVICE;
415 	else
416 		return DMA_FROM_DEVICE;
417 }
418 
419 /* Returns true if the max mtu allows page recycling */
420 static inline bool gve_can_recycle_pages(struct net_device *dev)
421 {
422 	/* We can't recycle the pages if we can't fit a packet into half a
423 	 * page.
424 	 */
425 	return dev->max_mtu <= PAGE_SIZE / 2;
426 }
427 
428 /* buffers */
429 int gve_alloc_page(struct device *dev, struct page **page, dma_addr_t *dma,
430 		   enum dma_data_direction);
431 void gve_free_page(struct device *dev, struct page *page, dma_addr_t dma,
432 		   enum dma_data_direction);
433 /* tx handling */
434 netdev_tx_t gve_tx(struct sk_buff *skb, struct net_device *dev);
435 bool gve_tx_poll(struct gve_notify_block *block, int budget);
436 int gve_tx_alloc_rings(struct gve_priv *priv);
437 void gve_tx_free_rings(struct gve_priv *priv);
438 __be32 gve_tx_load_event_counter(struct gve_priv *priv,
439 				 struct gve_tx_ring *tx);
440 /* rx handling */
441 void gve_rx_write_doorbell(struct gve_priv *priv, struct gve_rx_ring *rx);
442 bool gve_rx_poll(struct gve_notify_block *block, int budget);
443 int gve_rx_alloc_rings(struct gve_priv *priv);
444 void gve_rx_free_rings(struct gve_priv *priv);
445 bool gve_clean_rx_done(struct gve_rx_ring *rx, int budget,
446 		       netdev_features_t feat);
447 /* Reset */
448 void gve_schedule_reset(struct gve_priv *priv);
449 int gve_reset(struct gve_priv *priv, bool attempt_teardown);
450 int gve_adjust_queues(struct gve_priv *priv,
451 		      struct gve_queue_config new_rx_config,
452 		      struct gve_queue_config new_tx_config);
453 /* exported by ethtool.c */
454 extern const struct ethtool_ops gve_ethtool_ops;
455 /* needed by ethtool */
456 extern const char gve_version_str[];
457 #endif /* _GVE_H_ */
458