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
17  * details.
18  **********************************************************************/
19 #include <linux/pci.h>
20 #include <linux/netdevice.h>
21 #include "liquidio_common.h"
22 #include "octeon_droq.h"
23 #include "octeon_iq.h"
24 #include "response_manager.h"
25 #include "octeon_device.h"
26 #include "octeon_main.h"
27 
28 static void oct_poll_req_completion(struct work_struct *work);
29 
30 int octeon_setup_response_list(struct octeon_device *oct)
31 {
32 	int i, ret = 0;
33 	struct cavium_wq *cwq;
34 
35 	for (i = 0; i < MAX_RESPONSE_LISTS; i++) {
36 		INIT_LIST_HEAD(&oct->response_list[i].head);
37 		spin_lock_init(&oct->response_list[i].lock);
38 		atomic_set(&oct->response_list[i].pending_req_count, 0);
39 	}
40 	spin_lock_init(&oct->cmd_resp_wqlock);
41 
42 	oct->dma_comp_wq.wq = alloc_workqueue("dma-comp", WQ_MEM_RECLAIM, 0);
43 	if (!oct->dma_comp_wq.wq) {
44 		dev_err(&oct->pci_dev->dev, "failed to create wq thread\n");
45 		return -ENOMEM;
46 	}
47 
48 	cwq = &oct->dma_comp_wq;
49 	INIT_DELAYED_WORK(&cwq->wk.work, oct_poll_req_completion);
50 	cwq->wk.ctxptr = oct;
51 	oct->cmd_resp_state = OCT_DRV_ONLINE;
52 	queue_delayed_work(cwq->wq, &cwq->wk.work, msecs_to_jiffies(50));
53 
54 	return ret;
55 }
56 
57 void octeon_delete_response_list(struct octeon_device *oct)
58 {
59 	cancel_delayed_work_sync(&oct->dma_comp_wq.wk.work);
60 	destroy_workqueue(oct->dma_comp_wq.wq);
61 }
62 
63 int lio_process_ordered_list(struct octeon_device *octeon_dev,
64 			     u32 force_quit)
65 {
66 	struct octeon_response_list *ordered_sc_list;
67 	struct octeon_soft_command *sc;
68 	int request_complete = 0;
69 	int resp_to_process = MAX_ORD_REQS_TO_PROCESS;
70 	u32 status;
71 	u64 status64;
72 	struct octeon_instr_rdp *rdp;
73 	u64 rptr;
74 
75 	ordered_sc_list = &octeon_dev->response_list[OCTEON_ORDERED_SC_LIST];
76 
77 	do {
78 		spin_lock_bh(&ordered_sc_list->lock);
79 
80 		if (ordered_sc_list->head.next == &ordered_sc_list->head) {
81 			spin_unlock_bh(&ordered_sc_list->lock);
82 			return 1;
83 		}
84 
85 		sc = (struct octeon_soft_command *)ordered_sc_list->
86 		    head.next;
87 		if (OCTEON_CN23XX_PF(octeon_dev) ||
88 		    OCTEON_CN23XX_VF(octeon_dev)) {
89 			rdp = (struct octeon_instr_rdp *)&sc->cmd.cmd3.rdp;
90 			rptr = sc->cmd.cmd3.rptr;
91 		} else {
92 			rdp = (struct octeon_instr_rdp *)&sc->cmd.cmd2.rdp;
93 			rptr = sc->cmd.cmd2.rptr;
94 		}
95 
96 		status = OCTEON_REQUEST_PENDING;
97 
98 		/* check if octeon has finished DMA'ing a response
99 		 * to where rptr is pointing to
100 		 */
101 		dma_sync_single_for_cpu(&octeon_dev->pci_dev->dev,
102 					rptr, rdp->rlen,
103 					DMA_FROM_DEVICE);
104 		status64 = *sc->status_word;
105 
106 		if (status64 != COMPLETION_WORD_INIT) {
107 			if ((status64 & 0xff) != 0xff) {
108 				octeon_swap_8B_data(&status64, 1);
109 				if (((status64 & 0xff) != 0xff)) {
110 					status = (u32)(status64 &
111 						       0xffffffffULL);
112 				}
113 			}
114 		} else if (force_quit || (sc->timeout &&
115 			time_after(jiffies, (unsigned long)sc->timeout))) {
116 			status = OCTEON_REQUEST_TIMEOUT;
117 		}
118 
119 		if (status != OCTEON_REQUEST_PENDING) {
120 			/* we have received a response or we have timed out */
121 			/* remove node from linked list */
122 			list_del(&sc->node);
123 			atomic_dec(&octeon_dev->response_list
124 					  [OCTEON_ORDERED_SC_LIST].
125 					  pending_req_count);
126 			spin_unlock_bh
127 			    (&ordered_sc_list->lock);
128 
129 			if (sc->callback)
130 				sc->callback(octeon_dev, status,
131 					     sc->callback_arg);
132 
133 			request_complete++;
134 
135 		} else {
136 			/* no response yet */
137 			request_complete = 0;
138 			spin_unlock_bh
139 			    (&ordered_sc_list->lock);
140 		}
141 
142 		/* If we hit the Max Ordered requests to process every loop,
143 		 * we quit
144 		 * and let this function be invoked the next time the poll
145 		 * thread runs
146 		 * to process the remaining requests. This function can take up
147 		 * the entire CPU if there is no upper limit to the requests
148 		 * processed.
149 		 */
150 		if (request_complete >= resp_to_process)
151 			break;
152 	} while (request_complete);
153 
154 	return 0;
155 }
156 
157 static void oct_poll_req_completion(struct work_struct *work)
158 {
159 	struct cavium_wk *wk = (struct cavium_wk *)work;
160 	struct octeon_device *oct = (struct octeon_device *)wk->ctxptr;
161 	struct cavium_wq *cwq = &oct->dma_comp_wq;
162 
163 	lio_process_ordered_list(oct, 0);
164 	queue_delayed_work(cwq->wq, &cwq->wk.work, msecs_to_jiffies(50));
165 }
166