xref: /openbmc/linux/drivers/net/ethernet/google/gve/gve.h (revision b8d312aa)
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 	u32 cnt; /* free-running total number of completed packets */
35 	u32 fill_cnt; /* free-running total number of descriptors posted */
36 	u32 mask; /* masks the cnt to the size of the ring */
37 	u8 seqno; /* the next expected seqno for this desc*/
38 };
39 
40 /* The page info for a single slot in the RX data queue */
41 struct gve_rx_slot_page_info {
42 	struct page *page;
43 	void *page_address;
44 	u32 page_offset; /* offset to write to in page */
45 };
46 
47 /* A list of pages registered with the device during setup and used by a queue
48  * as buffers
49  */
50 struct gve_queue_page_list {
51 	u32 id; /* unique id */
52 	u32 num_entries;
53 	struct page **pages; /* list of num_entries pages */
54 	dma_addr_t *page_buses; /* the dma addrs of the pages */
55 };
56 
57 /* Each slot in the data ring has a 1:1 mapping to a slot in the desc ring */
58 struct gve_rx_data_queue {
59 	struct gve_rx_data_slot *data_ring; /* read by NIC */
60 	dma_addr_t data_bus; /* dma mapping of the slots */
61 	struct gve_rx_slot_page_info *page_info; /* page info of the buffers */
62 	struct gve_queue_page_list *qpl; /* qpl assigned to this queue */
63 	u32 mask; /* masks the cnt to the size of the ring */
64 	u32 cnt; /* free-running total number of completed packets */
65 };
66 
67 struct gve_priv;
68 
69 /* An RX ring that contains a power-of-two sized desc and data ring. */
70 struct gve_rx_ring {
71 	struct gve_priv *gve;
72 	struct gve_rx_desc_queue desc;
73 	struct gve_rx_data_queue data;
74 	u64 rbytes; /* free-running bytes received */
75 	u64 rpackets; /* free-running packets received */
76 	u32 q_num; /* queue index */
77 	u32 ntfy_id; /* notification block index */
78 	struct gve_queue_resources *q_resources; /* head and tail pointer idx */
79 	dma_addr_t q_resources_bus; /* dma address for the queue resources */
80 	struct u64_stats_sync statss; /* sync stats for 32bit archs */
81 };
82 
83 /* A TX desc ring entry */
84 union gve_tx_desc {
85 	struct gve_tx_pkt_desc pkt; /* first desc for a packet */
86 	struct gve_tx_seg_desc seg; /* subsequent descs for a packet */
87 };
88 
89 /* Tracks the memory in the fifo occupied by a segment of a packet */
90 struct gve_tx_iovec {
91 	u32 iov_offset; /* offset into this segment */
92 	u32 iov_len; /* length */
93 	u32 iov_padding; /* padding associated with this segment */
94 };
95 
96 /* Tracks the memory in the fifo occupied by the skb. Mapped 1:1 to a desc
97  * ring entry but only used for a pkt_desc not a seg_desc
98  */
99 struct gve_tx_buffer_state {
100 	struct sk_buff *skb; /* skb for this pkt */
101 	struct gve_tx_iovec iov[GVE_TX_MAX_IOVEC]; /* segments of this pkt */
102 };
103 
104 /* A TX buffer - each queue has one */
105 struct gve_tx_fifo {
106 	void *base; /* address of base of FIFO */
107 	u32 size; /* total size */
108 	atomic_t available; /* how much space is still available */
109 	u32 head; /* offset to write at */
110 	struct gve_queue_page_list *qpl; /* QPL mapped into this FIFO */
111 };
112 
113 /* A TX ring that contains a power-of-two sized desc ring and a FIFO buffer */
114 struct gve_tx_ring {
115 	/* Cacheline 0 -- Accessed & dirtied during transmit */
116 	struct gve_tx_fifo tx_fifo;
117 	u32 req; /* driver tracked head pointer */
118 	u32 done; /* driver tracked tail pointer */
119 
120 	/* Cacheline 1 -- Accessed & dirtied during gve_clean_tx_done */
121 	__be32 last_nic_done ____cacheline_aligned; /* NIC tail pointer */
122 	u64 pkt_done; /* free-running - total packets completed */
123 	u64 bytes_done; /* free-running - total bytes completed */
124 
125 	/* Cacheline 2 -- Read-mostly fields */
126 	union gve_tx_desc *desc ____cacheline_aligned;
127 	struct gve_tx_buffer_state *info; /* Maps 1:1 to a desc */
128 	struct netdev_queue *netdev_txq;
129 	struct gve_queue_resources *q_resources; /* head and tail pointer idx */
130 	u32 mask; /* masks req and done down to queue size */
131 
132 	/* Slow-path fields */
133 	u32 q_num ____cacheline_aligned; /* queue idx */
134 	u32 stop_queue; /* count of queue stops */
135 	u32 wake_queue; /* count of queue wakes */
136 	u32 ntfy_id; /* notification block index */
137 	dma_addr_t bus; /* dma address of the descr ring */
138 	dma_addr_t q_resources_bus; /* dma address of the queue resources */
139 	struct u64_stats_sync statss; /* sync stats for 32bit archs */
140 } ____cacheline_aligned;
141 
142 /* Wraps the info for one irq including the napi struct and the queues
143  * associated with that irq.
144  */
145 struct gve_notify_block {
146 	__be32 irq_db_index; /* idx into Bar2 - set by device, must be 1st */
147 	char name[IFNAMSIZ + 16]; /* name registered with the kernel */
148 	struct napi_struct napi; /* kernel napi struct for this block */
149 	struct gve_priv *priv;
150 	struct gve_tx_ring *tx; /* tx rings on this block */
151 	struct gve_rx_ring *rx; /* rx rings on this block */
152 } ____cacheline_aligned;
153 
154 /* Tracks allowed and current queue settings */
155 struct gve_queue_config {
156 	u16 max_queues;
157 	u16 num_queues; /* current */
158 };
159 
160 /* Tracks the available and used qpl IDs */
161 struct gve_qpl_config {
162 	u32 qpl_map_size; /* map memory size */
163 	unsigned long *qpl_id_map; /* bitmap of used qpl ids */
164 };
165 
166 struct gve_priv {
167 	struct net_device *dev;
168 	struct gve_tx_ring *tx; /* array of tx_cfg.num_queues */
169 	struct gve_rx_ring *rx; /* array of rx_cfg.num_queues */
170 	struct gve_queue_page_list *qpls; /* array of num qpls */
171 	struct gve_notify_block *ntfy_blocks; /* array of num_ntfy_blks */
172 	dma_addr_t ntfy_block_bus;
173 	struct msix_entry *msix_vectors; /* array of num_ntfy_blks + 1 */
174 	char mgmt_msix_name[IFNAMSIZ + 16];
175 	u32 mgmt_msix_idx;
176 	__be32 *counter_array; /* array of num_event_counters */
177 	dma_addr_t counter_array_bus;
178 
179 	u16 num_event_counters;
180 	u16 tx_desc_cnt; /* num desc per ring */
181 	u16 rx_desc_cnt; /* num desc per ring */
182 	u16 tx_pages_per_qpl; /* tx buffer length */
183 	u16 rx_pages_per_qpl; /* rx buffer length */
184 	u64 max_registered_pages;
185 	u64 num_registered_pages; /* num pages registered with NIC */
186 	u32 rx_copybreak; /* copy packets smaller than this */
187 	u16 default_num_queues; /* default num queues to set up */
188 
189 	struct gve_queue_config tx_cfg;
190 	struct gve_queue_config rx_cfg;
191 	struct gve_qpl_config qpl_cfg; /* map used QPL ids */
192 	u32 num_ntfy_blks; /* spilt between TX and RX so must be even */
193 
194 	struct gve_registers __iomem *reg_bar0; /* see gve_register.h */
195 	__be32 __iomem *db_bar2; /* "array" of doorbells */
196 	u32 msg_enable;	/* level for netif* netdev print macros	*/
197 	struct pci_dev *pdev;
198 
199 	/* metrics */
200 	u32 tx_timeo_cnt;
201 
202 	/* Admin queue - see gve_adminq.h*/
203 	union gve_adminq_command *adminq;
204 	dma_addr_t adminq_bus_addr;
205 	u32 adminq_mask; /* masks prod_cnt to adminq size */
206 	u32 adminq_prod_cnt; /* free-running count of AQ cmds executed */
207 
208 	struct workqueue_struct *gve_wq;
209 	struct work_struct service_task;
210 	unsigned long service_task_flags;
211 	unsigned long state_flags;
212 };
213 
214 enum gve_service_task_flags {
215 	GVE_PRIV_FLAGS_DO_RESET			= BIT(1),
216 	GVE_PRIV_FLAGS_RESET_IN_PROGRESS	= BIT(2),
217 	GVE_PRIV_FLAGS_PROBE_IN_PROGRESS	= BIT(3),
218 };
219 
220 enum gve_state_flags {
221 	GVE_PRIV_FLAGS_ADMIN_QUEUE_OK		= BIT(1),
222 	GVE_PRIV_FLAGS_DEVICE_RESOURCES_OK	= BIT(2),
223 	GVE_PRIV_FLAGS_DEVICE_RINGS_OK		= BIT(3),
224 	GVE_PRIV_FLAGS_NAPI_ENABLED		= BIT(4),
225 };
226 
227 static inline bool gve_get_do_reset(struct gve_priv *priv)
228 {
229 	return test_bit(GVE_PRIV_FLAGS_DO_RESET, &priv->service_task_flags);
230 }
231 
232 static inline void gve_set_do_reset(struct gve_priv *priv)
233 {
234 	set_bit(GVE_PRIV_FLAGS_DO_RESET, &priv->service_task_flags);
235 }
236 
237 static inline void gve_clear_do_reset(struct gve_priv *priv)
238 {
239 	clear_bit(GVE_PRIV_FLAGS_DO_RESET, &priv->service_task_flags);
240 }
241 
242 static inline bool gve_get_reset_in_progress(struct gve_priv *priv)
243 {
244 	return test_bit(GVE_PRIV_FLAGS_RESET_IN_PROGRESS,
245 			&priv->service_task_flags);
246 }
247 
248 static inline void gve_set_reset_in_progress(struct gve_priv *priv)
249 {
250 	set_bit(GVE_PRIV_FLAGS_RESET_IN_PROGRESS, &priv->service_task_flags);
251 }
252 
253 static inline void gve_clear_reset_in_progress(struct gve_priv *priv)
254 {
255 	clear_bit(GVE_PRIV_FLAGS_RESET_IN_PROGRESS, &priv->service_task_flags);
256 }
257 
258 static inline bool gve_get_probe_in_progress(struct gve_priv *priv)
259 {
260 	return test_bit(GVE_PRIV_FLAGS_PROBE_IN_PROGRESS,
261 			&priv->service_task_flags);
262 }
263 
264 static inline void gve_set_probe_in_progress(struct gve_priv *priv)
265 {
266 	set_bit(GVE_PRIV_FLAGS_PROBE_IN_PROGRESS, &priv->service_task_flags);
267 }
268 
269 static inline void gve_clear_probe_in_progress(struct gve_priv *priv)
270 {
271 	clear_bit(GVE_PRIV_FLAGS_PROBE_IN_PROGRESS, &priv->service_task_flags);
272 }
273 
274 static inline bool gve_get_admin_queue_ok(struct gve_priv *priv)
275 {
276 	return test_bit(GVE_PRIV_FLAGS_ADMIN_QUEUE_OK, &priv->state_flags);
277 }
278 
279 static inline void gve_set_admin_queue_ok(struct gve_priv *priv)
280 {
281 	set_bit(GVE_PRIV_FLAGS_ADMIN_QUEUE_OK, &priv->state_flags);
282 }
283 
284 static inline void gve_clear_admin_queue_ok(struct gve_priv *priv)
285 {
286 	clear_bit(GVE_PRIV_FLAGS_ADMIN_QUEUE_OK, &priv->state_flags);
287 }
288 
289 static inline bool gve_get_device_resources_ok(struct gve_priv *priv)
290 {
291 	return test_bit(GVE_PRIV_FLAGS_DEVICE_RESOURCES_OK, &priv->state_flags);
292 }
293 
294 static inline void gve_set_device_resources_ok(struct gve_priv *priv)
295 {
296 	set_bit(GVE_PRIV_FLAGS_DEVICE_RESOURCES_OK, &priv->state_flags);
297 }
298 
299 static inline void gve_clear_device_resources_ok(struct gve_priv *priv)
300 {
301 	clear_bit(GVE_PRIV_FLAGS_DEVICE_RESOURCES_OK, &priv->state_flags);
302 }
303 
304 static inline bool gve_get_device_rings_ok(struct gve_priv *priv)
305 {
306 	return test_bit(GVE_PRIV_FLAGS_DEVICE_RINGS_OK, &priv->state_flags);
307 }
308 
309 static inline void gve_set_device_rings_ok(struct gve_priv *priv)
310 {
311 	set_bit(GVE_PRIV_FLAGS_DEVICE_RINGS_OK, &priv->state_flags);
312 }
313 
314 static inline void gve_clear_device_rings_ok(struct gve_priv *priv)
315 {
316 	clear_bit(GVE_PRIV_FLAGS_DEVICE_RINGS_OK, &priv->state_flags);
317 }
318 
319 static inline bool gve_get_napi_enabled(struct gve_priv *priv)
320 {
321 	return test_bit(GVE_PRIV_FLAGS_NAPI_ENABLED, &priv->state_flags);
322 }
323 
324 static inline void gve_set_napi_enabled(struct gve_priv *priv)
325 {
326 	set_bit(GVE_PRIV_FLAGS_NAPI_ENABLED, &priv->state_flags);
327 }
328 
329 static inline void gve_clear_napi_enabled(struct gve_priv *priv)
330 {
331 	clear_bit(GVE_PRIV_FLAGS_NAPI_ENABLED, &priv->state_flags);
332 }
333 
334 /* Returns the address of the ntfy_blocks irq doorbell
335  */
336 static inline __be32 __iomem *gve_irq_doorbell(struct gve_priv *priv,
337 					       struct gve_notify_block *block)
338 {
339 	return &priv->db_bar2[be32_to_cpu(block->irq_db_index)];
340 }
341 
342 /* Returns the index into ntfy_blocks of the given tx ring's block
343  */
344 static inline u32 gve_tx_idx_to_ntfy(struct gve_priv *priv, u32 queue_idx)
345 {
346 	return queue_idx;
347 }
348 
349 /* Returns the index into ntfy_blocks of the given rx ring's block
350  */
351 static inline u32 gve_rx_idx_to_ntfy(struct gve_priv *priv, u32 queue_idx)
352 {
353 	return (priv->num_ntfy_blks / 2) + queue_idx;
354 }
355 
356 /* Returns the number of tx queue page lists
357  */
358 static inline u32 gve_num_tx_qpls(struct gve_priv *priv)
359 {
360 	return priv->tx_cfg.num_queues;
361 }
362 
363 /* Returns the number of rx queue page lists
364  */
365 static inline u32 gve_num_rx_qpls(struct gve_priv *priv)
366 {
367 	return priv->rx_cfg.num_queues;
368 }
369 
370 /* Returns a pointer to the next available tx qpl in the list of qpls
371  */
372 static inline
373 struct gve_queue_page_list *gve_assign_tx_qpl(struct gve_priv *priv)
374 {
375 	int id = find_first_zero_bit(priv->qpl_cfg.qpl_id_map,
376 				     priv->qpl_cfg.qpl_map_size);
377 
378 	/* we are out of tx qpls */
379 	if (id >= gve_num_tx_qpls(priv))
380 		return NULL;
381 
382 	set_bit(id, priv->qpl_cfg.qpl_id_map);
383 	return &priv->qpls[id];
384 }
385 
386 /* Returns a pointer to the next available rx qpl in the list of qpls
387  */
388 static inline
389 struct gve_queue_page_list *gve_assign_rx_qpl(struct gve_priv *priv)
390 {
391 	int id = find_next_zero_bit(priv->qpl_cfg.qpl_id_map,
392 				    priv->qpl_cfg.qpl_map_size,
393 				    gve_num_tx_qpls(priv));
394 
395 	/* we are out of rx qpls */
396 	if (id == priv->qpl_cfg.qpl_map_size)
397 		return NULL;
398 
399 	set_bit(id, priv->qpl_cfg.qpl_id_map);
400 	return &priv->qpls[id];
401 }
402 
403 /* Unassigns the qpl with the given id
404  */
405 static inline void gve_unassign_qpl(struct gve_priv *priv, int id)
406 {
407 	clear_bit(id, priv->qpl_cfg.qpl_id_map);
408 }
409 
410 /* Returns the correct dma direction for tx and rx qpls
411  */
412 static inline enum dma_data_direction gve_qpl_dma_dir(struct gve_priv *priv,
413 						      int id)
414 {
415 	if (id < gve_num_tx_qpls(priv))
416 		return DMA_TO_DEVICE;
417 	else
418 		return DMA_FROM_DEVICE;
419 }
420 
421 /* Returns true if the max mtu allows page recycling */
422 static inline bool gve_can_recycle_pages(struct net_device *dev)
423 {
424 	/* We can't recycle the pages if we can't fit a packet into half a
425 	 * page.
426 	 */
427 	return dev->max_mtu <= PAGE_SIZE / 2;
428 }
429 
430 /* buffers */
431 int gve_alloc_page(struct device *dev, struct page **page, dma_addr_t *dma,
432 		   enum dma_data_direction);
433 void gve_free_page(struct device *dev, struct page *page, dma_addr_t dma,
434 		   enum dma_data_direction);
435 /* tx handling */
436 netdev_tx_t gve_tx(struct sk_buff *skb, struct net_device *dev);
437 bool gve_tx_poll(struct gve_notify_block *block, int budget);
438 int gve_tx_alloc_rings(struct gve_priv *priv);
439 void gve_tx_free_rings(struct gve_priv *priv);
440 __be32 gve_tx_load_event_counter(struct gve_priv *priv,
441 				 struct gve_tx_ring *tx);
442 /* rx handling */
443 void gve_rx_write_doorbell(struct gve_priv *priv, struct gve_rx_ring *rx);
444 bool gve_rx_poll(struct gve_notify_block *block, int budget);
445 int gve_rx_alloc_rings(struct gve_priv *priv);
446 void gve_rx_free_rings(struct gve_priv *priv);
447 bool gve_clean_rx_done(struct gve_rx_ring *rx, int budget,
448 		       netdev_features_t feat);
449 /* Reset */
450 void gve_schedule_reset(struct gve_priv *priv);
451 int gve_reset(struct gve_priv *priv, bool attempt_teardown);
452 int gve_adjust_queues(struct gve_priv *priv,
453 		      struct gve_queue_config new_rx_config,
454 		      struct gve_queue_config new_tx_config);
455 /* exported by ethtool.c */
456 extern const struct ethtool_ops gve_ethtool_ops;
457 /* needed by ethtool */
458 extern const char gve_version_str[];
459 #endif /* _GVE_H_ */
460