1 /**********************************************************************
2  * Author: Cavium, Inc.
3  *
4  * Contact: support@cavium.com
5  *          Please include "LiquidIO" in the subject.
6  *
7  * Copyright (c) 2003-2016 Cavium, Inc.
8  *
9  * This file is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License, Version 2, as
11  * published by the Free Software Foundation.
12  *
13  * This file is distributed in the hope that it will be useful, but
14  * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
15  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
16  * NONINFRINGEMENT.  See the GNU General Public License for more details.
17  ***********************************************************************/
18 /*!  \file  octeon_droq.h
19  *   \brief Implementation of Octeon Output queues. "Output" is with
20  *   respect to the Octeon device on the NIC. From this driver's point of
21  *   view they are ingress queues.
22  */
23 
24 #ifndef __OCTEON_DROQ_H__
25 #define __OCTEON_DROQ_H__
26 
27 /* Default number of packets that will be processed in one iteration. */
28 #define MAX_PACKET_BUDGET 0xFFFFFFFF
29 
30 /** Octeon descriptor format.
31  *  The descriptor ring is made of descriptors which have 2 64-bit values:
32  *  -# Physical (bus) address of the data buffer.
33  *  -# Physical (bus) address of a octeon_droq_info structure.
34  *  The Octeon device DMA's incoming packets and its information at the address
35  *  given by these descriptor fields.
36  */
37 struct octeon_droq_desc {
38 	/** The buffer pointer */
39 	u64 buffer_ptr;
40 
41 	/** The Info pointer */
42 	u64 info_ptr;
43 };
44 
45 #define OCT_DROQ_DESC_SIZE    (sizeof(struct octeon_droq_desc))
46 
47 /** Information about packet DMA'ed by Octeon.
48  *  The format of the information available at Info Pointer after Octeon
49  *  has posted a packet. Not all descriptors have valid information. Only
50  *  the Info field of the first descriptor for a packet has information
51  *  about the packet.
52  */
53 struct octeon_droq_info {
54 	/** The Length of the packet. */
55 	u64 length;
56 
57 	/** The Output Receive Header. */
58 	union octeon_rh rh;
59 };
60 
61 #define OCT_DROQ_INFO_SIZE   (sizeof(struct octeon_droq_info))
62 
63 struct octeon_skb_page_info {
64 	/* DMA address for the page */
65 	dma_addr_t dma;
66 
67 	/* Page for the rx dma  **/
68 	struct page *page;
69 
70 	/** which offset into page */
71 	unsigned int page_offset;
72 };
73 
74 /** Pointer to data buffer.
75  *  Driver keeps a pointer to the data buffer that it made available to
76  *  the Octeon device. Since the descriptor ring keeps physical (bus)
77  *  addresses, this field is required for the driver to keep track of
78  *  the virtual address pointers.
79  */
80 struct octeon_recv_buffer {
81 	/** Packet buffer, including metadata. */
82 	void *buffer;
83 
84 	/** Data in the packet buffer.  */
85 	u8 *data;
86 
87 	/** pg_info **/
88 	struct octeon_skb_page_info pg_info;
89 };
90 
91 #define OCT_DROQ_RECVBUF_SIZE    (sizeof(struct octeon_recv_buffer))
92 
93 /** Output Queue statistics. Each output queue has four stats fields. */
94 struct oct_droq_stats {
95 	/** Number of packets received in this queue. */
96 	u64 pkts_received;
97 
98 	/** Bytes received by this queue. */
99 	u64 bytes_received;
100 
101 	/** Packets dropped due to no dispatch function. */
102 	u64 dropped_nodispatch;
103 
104 	/** Packets dropped due to no memory available. */
105 	u64 dropped_nomem;
106 
107 	/** Packets dropped due to large number of pkts to process. */
108 	u64 dropped_toomany;
109 
110 	/** Number of packets  sent to stack from this queue. */
111 	u64 rx_pkts_received;
112 
113 	/** Number of Bytes sent to stack from this queue. */
114 	u64 rx_bytes_received;
115 
116 	/** Num of Packets dropped due to receive path failures. */
117 	u64 rx_dropped;
118 
119 	u64 rx_vxlan;
120 
121 	/** Num of failures of recv_buffer_alloc() */
122 	u64 rx_alloc_failure;
123 
124 };
125 
126 /* The maximum number of buffers that can be dispatched from the
127  * output/dma queue. Set to 64 assuming 1K buffers in DROQ and the fact that
128  * max packet size from DROQ is 64K.
129  */
130 #define    MAX_RECV_BUFS    64
131 
132 /** Receive Packet format used when dispatching output queue packets
133  *  with non-raw opcodes.
134  *  The received packet will be sent to the upper layers using this
135  *  structure which is passed as a parameter to the dispatch function
136  */
137 struct octeon_recv_pkt {
138 	/**  Number of buffers in this received packet */
139 	u16 buffer_count;
140 
141 	/** Id of the device that is sending the packet up */
142 	u16 octeon_id;
143 
144 	/** Length of data in the packet buffer */
145 	u32 length;
146 
147 	/** The receive header */
148 	union octeon_rh rh;
149 
150 	/** Pointer to the OS-specific packet buffer */
151 	void *buffer_ptr[MAX_RECV_BUFS];
152 
153 	/** Size of the buffers pointed to by ptr's in buffer_ptr */
154 	u32 buffer_size[MAX_RECV_BUFS];
155 };
156 
157 #define OCT_RECV_PKT_SIZE    (sizeof(struct octeon_recv_pkt))
158 
159 /** The first parameter of a dispatch function.
160  *  For a raw mode opcode, the driver dispatches with the device
161  *  pointer in this structure.
162  *  For non-raw mode opcode, the driver dispatches the recv_pkt
163  *  created to contain the buffers with data received from Octeon.
164  *  ---------------------
165  *  |     *recv_pkt ----|---
166  *  |-------------------|   |
167  *  | 0 or more bytes   |   |
168  *  | reserved by driver|   |
169  *  |-------------------|<-/
170  *  | octeon_recv_pkt   |
171  *  |                   |
172  *  |___________________|
173  */
174 struct octeon_recv_info {
175 	void *rsvd;
176 	struct octeon_recv_pkt *recv_pkt;
177 };
178 
179 #define  OCT_RECV_INFO_SIZE    (sizeof(struct octeon_recv_info))
180 
181 /** Allocate a recv_info structure. The recv_pkt pointer in the recv_info
182  *  structure is filled in before this call returns.
183  *  @param extra_bytes - extra bytes to be allocated at the end of the recv info
184  *                       structure.
185  *  @return - pointer to a newly allocated recv_info structure.
186  */
187 static inline struct octeon_recv_info *octeon_alloc_recv_info(int extra_bytes)
188 {
189 	struct octeon_recv_info *recv_info;
190 	u8 *buf;
191 
192 	buf = kmalloc(OCT_RECV_PKT_SIZE + OCT_RECV_INFO_SIZE +
193 		      extra_bytes, GFP_ATOMIC);
194 	if (!buf)
195 		return NULL;
196 
197 	recv_info = (struct octeon_recv_info *)buf;
198 	recv_info->recv_pkt =
199 		(struct octeon_recv_pkt *)(buf + OCT_RECV_INFO_SIZE);
200 	recv_info->rsvd = NULL;
201 	if (extra_bytes)
202 		recv_info->rsvd = buf + OCT_RECV_INFO_SIZE + OCT_RECV_PKT_SIZE;
203 
204 	return recv_info;
205 }
206 
207 /** Free a recv_info structure.
208  *  @param recv_info - Pointer to receive_info to be freed
209  */
210 static inline void octeon_free_recv_info(struct octeon_recv_info *recv_info)
211 {
212 	kfree(recv_info);
213 }
214 
215 typedef int (*octeon_dispatch_fn_t)(struct octeon_recv_info *, void *);
216 
217 /** Used by NIC module to register packet handler and to get device
218  * information for each octeon device.
219  */
220 struct octeon_droq_ops {
221 	/** This registered function will be called by the driver with
222 	 *  the octeon id, pointer to buffer from droq and length of
223 	 *  data in the buffer. The receive header gives the port
224 	 *  number to the caller.  Function pointer is set by caller.
225 	 */
226 	void (*fptr)(u32, void *, u32, union octeon_rh *, void *, void *);
227 	void *farg;
228 
229 	/* This function will be called by the driver for all NAPI related
230 	 * events. The first param is the octeon id. The second param is the
231 	 * output queue number. The third is the NAPI event that occurred.
232 	 */
233 	void (*napi_fn)(void *);
234 
235 	u32 poll_mode;
236 
237 	/** Flag indicating if the DROQ handler should drop packets that
238 	 *  it cannot handle in one iteration. Set by caller.
239 	 */
240 	u32 drop_on_max;
241 };
242 
243 /** The Descriptor Ring Output Queue structure.
244  *  This structure has all the information required to implement a
245  *  Octeon DROQ.
246  */
247 struct octeon_droq {
248 	u32 q_no;
249 
250 	u32 pkt_count;
251 
252 	struct octeon_droq_ops ops;
253 
254 	struct octeon_device *oct_dev;
255 
256 	/** The 8B aligned descriptor ring starts at this address. */
257 	struct octeon_droq_desc *desc_ring;
258 
259 	/** Index in the ring where the driver should read the next packet */
260 	u32 read_idx;
261 
262 	/** Index in the ring where Octeon will write the next packet */
263 	u32 write_idx;
264 
265 	/** Index in the ring where the driver will refill the descriptor's
266 	 * buffer
267 	 */
268 	u32 refill_idx;
269 
270 	/** Packets pending to be processed */
271 	atomic_t pkts_pending;
272 
273 	/** Number of  descriptors in this ring. */
274 	u32 max_count;
275 
276 	/** The number of descriptors pending refill. */
277 	u32 refill_count;
278 
279 	u32 pkts_per_intr;
280 	u32 refill_threshold;
281 
282 	/** The max number of descriptors in DROQ without a buffer.
283 	 * This field is used to keep track of empty space threshold. If the
284 	 * refill_count reaches this value, the DROQ cannot accept a max-sized
285 	 * (64K) packet.
286 	 */
287 	u32 max_empty_descs;
288 
289 	/** The receive buffer list. This list has the virtual addresses of the
290 	 * buffers.
291 	 */
292 	struct octeon_recv_buffer *recv_buf_list;
293 
294 	/** The size of each buffer pointed by the buffer pointer. */
295 	u32 buffer_size;
296 
297 	/** Pointer to the mapped packet credit register.
298 	 * Host writes number of info/buffer ptrs available to this register
299 	 */
300 	void  __iomem *pkts_credit_reg;
301 
302 	/** Pointer to the mapped packet sent register.
303 	 * Octeon writes the number of packets DMA'ed to host memory
304 	 * in this register.
305 	 */
306 	void __iomem *pkts_sent_reg;
307 
308 	struct list_head dispatch_list;
309 
310 	/** Statistics for this DROQ. */
311 	struct oct_droq_stats stats;
312 
313 	/** DMA mapped address of the DROQ descriptor ring. */
314 	size_t desc_ring_dma;
315 
316 	/** application context */
317 	void *app_ctx;
318 
319 	struct napi_struct napi;
320 
321 	u32 cpu_id;
322 
323 	call_single_data_t csd;
324 };
325 
326 #define OCT_DROQ_SIZE   (sizeof(struct octeon_droq))
327 
328 /**
329  *  Allocates space for the descriptor ring for the droq and sets the
330  *   base addr, num desc etc in Octeon registers.
331  *
332  * @param  oct_dev    - pointer to the octeon device structure
333  * @param  q_no       - droq no. ranges from 0 - 3.
334  * @param app_ctx     - pointer to application context
335  * @return Success: 0    Failure: 1
336  */
337 int octeon_init_droq(struct octeon_device *oct_dev,
338 		     u32 q_no,
339 		     u32 num_descs,
340 		     u32 desc_size,
341 		     void *app_ctx);
342 
343 /**
344  *  Frees the space for descriptor ring for the droq.
345  *
346  *  @param oct_dev - pointer to the octeon device structure
347  *  @param q_no    - droq no. ranges from 0 - 3.
348  *  @return:    Success: 0    Failure: 1
349  */
350 int octeon_delete_droq(struct octeon_device *oct_dev, u32 q_no);
351 
352 /** Register a change in droq operations. The ops field has a pointer to a
353  * function which will called by the DROQ handler for all packets arriving
354  * on output queues given by q_no irrespective of the type of packet.
355  * The ops field also has a flag which if set tells the DROQ handler to
356  * drop packets if it receives more than what it can process in one
357  * invocation of the handler.
358  * @param oct       - octeon device
359  * @param q_no      - octeon output queue number (0 <= q_no <= MAX_OCTEON_DROQ-1
360  * @param ops       - the droq_ops settings for this queue
361  * @return          - 0 on success, -ENODEV or -EINVAL on error.
362  */
363 int
364 octeon_register_droq_ops(struct octeon_device *oct,
365 			 u32 q_no,
366 			 struct octeon_droq_ops *ops);
367 
368 /** Resets the function pointer and flag settings made by
369  * octeon_register_droq_ops(). After this routine is called, the DROQ handler
370  * will lookup dispatch function for each arriving packet on the output queue
371  * given by q_no.
372  * @param oct       - octeon device
373  * @param q_no      - octeon output queue number (0 <= q_no <= MAX_OCTEON_DROQ-1
374  * @return          - 0 on success, -ENODEV or -EINVAL on error.
375  */
376 int octeon_unregister_droq_ops(struct octeon_device *oct, u32 q_no);
377 
378 /**   Register a dispatch function for a opcode/subcode. The driver will call
379  *    this dispatch function when it receives a packet with the given
380  *    opcode/subcode in its output queues along with the user specified
381  *    argument.
382  *    @param  oct        - the octeon device to register with.
383  *    @param  opcode     - the opcode for which the dispatch will be registered.
384  *    @param  subcode    - the subcode for which the dispatch will be registered
385  *    @param  fn         - the dispatch function.
386  *    @param  fn_arg     - user specified that will be passed along with the
387  *                         dispatch function by the driver.
388  *    @return Success: 0; Failure: 1
389  */
390 int octeon_register_dispatch_fn(struct octeon_device *oct,
391 				u16 opcode,
392 				u16 subcode,
393 				octeon_dispatch_fn_t fn, void *fn_arg);
394 
395 void *octeon_get_dispatch_arg(struct octeon_device *oct,
396 			      u16 opcode, u16 subcode);
397 
398 void octeon_droq_print_stats(void);
399 
400 u32 octeon_droq_check_hw_for_pkts(struct octeon_droq *droq);
401 
402 int octeon_create_droq(struct octeon_device *oct, u32 q_no,
403 		       u32 num_descs, u32 desc_size, void *app_ctx);
404 
405 int octeon_droq_process_packets(struct octeon_device *oct,
406 				struct octeon_droq *droq,
407 				u32 budget);
408 
409 int octeon_droq_process_poll_pkts(struct octeon_device *oct,
410 				  struct octeon_droq *droq, u32 budget);
411 
412 int octeon_enable_irq(struct octeon_device *oct, u32 q_no);
413 
414 int octeon_retry_droq_refill(struct octeon_droq *droq);
415 
416 #endif	/*__OCTEON_DROQ_H__ */
417