xref: /openbmc/linux/drivers/dma/idxd/dma.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 2019 Intel Corporation. All rights rsvd. */
3 #include <linux/init.h>
4 #include <linux/kernel.h>
5 #include <linux/module.h>
6 #include <linux/pci.h>
7 #include <linux/device.h>
8 #include <linux/io-64-nonatomic-lo-hi.h>
9 #include <linux/dmaengine.h>
10 #include <uapi/linux/idxd.h>
11 #include "../dmaengine.h"
12 #include "registers.h"
13 #include "idxd.h"
14 
15 static inline struct idxd_wq *to_idxd_wq(struct dma_chan *c)
16 {
17 	return container_of(c, struct idxd_wq, dma_chan);
18 }
19 
20 void idxd_dma_complete_txd(struct idxd_desc *desc,
21 			   enum idxd_complete_type comp_type)
22 {
23 	struct dma_async_tx_descriptor *tx;
24 	struct dmaengine_result res;
25 	int complete = 1;
26 
27 	if (desc->completion->status == DSA_COMP_SUCCESS)
28 		res.result = DMA_TRANS_NOERROR;
29 	else if (desc->completion->status)
30 		res.result = DMA_TRANS_WRITE_FAILED;
31 	else if (comp_type == IDXD_COMPLETE_ABORT)
32 		res.result = DMA_TRANS_ABORTED;
33 	else
34 		complete = 0;
35 
36 	tx = &desc->txd;
37 	if (complete && tx->cookie) {
38 		dma_cookie_complete(tx);
39 		dma_descriptor_unmap(tx);
40 		dmaengine_desc_get_callback_invoke(tx, &res);
41 		tx->callback = NULL;
42 		tx->callback_result = NULL;
43 	}
44 }
45 
46 static void op_flag_setup(unsigned long flags, u32 *desc_flags)
47 {
48 	*desc_flags = IDXD_OP_FLAG_CRAV | IDXD_OP_FLAG_RCR;
49 	if (flags & DMA_PREP_INTERRUPT)
50 		*desc_flags |= IDXD_OP_FLAG_RCI;
51 }
52 
53 static inline void set_completion_address(struct idxd_desc *desc,
54 					  u64 *compl_addr)
55 {
56 		*compl_addr = desc->compl_dma;
57 }
58 
59 static inline void idxd_prep_desc_common(struct idxd_wq *wq,
60 					 struct dsa_hw_desc *hw, char opcode,
61 					 u64 addr_f1, u64 addr_f2, u64 len,
62 					 u64 compl, u32 flags)
63 {
64 	struct idxd_device *idxd = wq->idxd;
65 
66 	hw->flags = flags;
67 	hw->opcode = opcode;
68 	hw->src_addr = addr_f1;
69 	hw->dst_addr = addr_f2;
70 	hw->xfer_size = len;
71 	hw->priv = !!(wq->type == IDXD_WQT_KERNEL);
72 	hw->completion_addr = compl;
73 
74 	/*
75 	 * Descriptor completion vectors are 1-8 for MSIX. We will round
76 	 * robin through the 8 vectors.
77 	 */
78 	wq->vec_ptr = (wq->vec_ptr % idxd->num_wq_irqs) + 1;
79 	hw->int_handle =  wq->vec_ptr;
80 }
81 
82 static struct dma_async_tx_descriptor *
83 idxd_dma_submit_memcpy(struct dma_chan *c, dma_addr_t dma_dest,
84 		       dma_addr_t dma_src, size_t len, unsigned long flags)
85 {
86 	struct idxd_wq *wq = to_idxd_wq(c);
87 	u32 desc_flags;
88 	struct idxd_device *idxd = wq->idxd;
89 	struct idxd_desc *desc;
90 
91 	if (wq->state != IDXD_WQ_ENABLED)
92 		return NULL;
93 
94 	if (len > idxd->max_xfer_bytes)
95 		return NULL;
96 
97 	op_flag_setup(flags, &desc_flags);
98 	desc = idxd_alloc_desc(wq, IDXD_OP_BLOCK);
99 	if (IS_ERR(desc))
100 		return NULL;
101 
102 	idxd_prep_desc_common(wq, desc->hw, DSA_OPCODE_MEMMOVE,
103 			      dma_src, dma_dest, len, desc->compl_dma,
104 			      desc_flags);
105 
106 	desc->txd.flags = flags;
107 
108 	return &desc->txd;
109 }
110 
111 static int idxd_dma_alloc_chan_resources(struct dma_chan *chan)
112 {
113 	struct idxd_wq *wq = to_idxd_wq(chan);
114 	struct device *dev = &wq->idxd->pdev->dev;
115 
116 	idxd_wq_get(wq);
117 	dev_dbg(dev, "%s: client_count: %d\n", __func__,
118 		idxd_wq_refcount(wq));
119 	return 0;
120 }
121 
122 static void idxd_dma_free_chan_resources(struct dma_chan *chan)
123 {
124 	struct idxd_wq *wq = to_idxd_wq(chan);
125 	struct device *dev = &wq->idxd->pdev->dev;
126 
127 	idxd_wq_put(wq);
128 	dev_dbg(dev, "%s: client_count: %d\n", __func__,
129 		idxd_wq_refcount(wq));
130 }
131 
132 static enum dma_status idxd_dma_tx_status(struct dma_chan *dma_chan,
133 					  dma_cookie_t cookie,
134 					  struct dma_tx_state *txstate)
135 {
136 	return dma_cookie_status(dma_chan, cookie, txstate);
137 }
138 
139 /*
140  * issue_pending() does not need to do anything since tx_submit() does the job
141  * already.
142  */
143 static void idxd_dma_issue_pending(struct dma_chan *dma_chan)
144 {
145 }
146 
147 dma_cookie_t idxd_dma_tx_submit(struct dma_async_tx_descriptor *tx)
148 {
149 	struct dma_chan *c = tx->chan;
150 	struct idxd_wq *wq = to_idxd_wq(c);
151 	dma_cookie_t cookie;
152 	int rc;
153 	struct idxd_desc *desc = container_of(tx, struct idxd_desc, txd);
154 
155 	cookie = dma_cookie_assign(tx);
156 
157 	rc = idxd_submit_desc(wq, desc);
158 	if (rc < 0) {
159 		idxd_free_desc(wq, desc);
160 		return rc;
161 	}
162 
163 	return cookie;
164 }
165 
166 static void idxd_dma_release(struct dma_device *device)
167 {
168 }
169 
170 int idxd_register_dma_device(struct idxd_device *idxd)
171 {
172 	struct dma_device *dma = &idxd->dma_dev;
173 
174 	INIT_LIST_HEAD(&dma->channels);
175 	dma->dev = &idxd->pdev->dev;
176 
177 	dma->device_release = idxd_dma_release;
178 
179 	if (idxd->hw.opcap.bits[0] & IDXD_OPCAP_MEMMOVE) {
180 		dma_cap_set(DMA_MEMCPY, dma->cap_mask);
181 		dma->device_prep_dma_memcpy = idxd_dma_submit_memcpy;
182 	}
183 
184 	dma->device_tx_status = idxd_dma_tx_status;
185 	dma->device_issue_pending = idxd_dma_issue_pending;
186 	dma->device_alloc_chan_resources = idxd_dma_alloc_chan_resources;
187 	dma->device_free_chan_resources = idxd_dma_free_chan_resources;
188 
189 	return dma_async_device_register(&idxd->dma_dev);
190 }
191 
192 void idxd_unregister_dma_device(struct idxd_device *idxd)
193 {
194 	dma_async_device_unregister(&idxd->dma_dev);
195 }
196 
197 int idxd_register_dma_channel(struct idxd_wq *wq)
198 {
199 	struct idxd_device *idxd = wq->idxd;
200 	struct dma_device *dma = &idxd->dma_dev;
201 	struct dma_chan *chan = &wq->dma_chan;
202 	int rc;
203 
204 	memset(&wq->dma_chan, 0, sizeof(struct dma_chan));
205 	chan->device = dma;
206 	list_add_tail(&chan->device_node, &dma->channels);
207 	rc = dma_async_device_channel_register(dma, chan);
208 	if (rc < 0)
209 		return rc;
210 
211 	return 0;
212 }
213 
214 void idxd_unregister_dma_channel(struct idxd_wq *wq)
215 {
216 	dma_async_device_channel_unregister(&wq->idxd->dma_dev, &wq->dma_chan);
217 }
218