saa7164-buffer.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *  Driver for the NXP SAA7164 PCIe bridge
  4 *
  5 *  Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
  6 */
  7
  8#include <linux/slab.h>
  9
 10#include "saa7164.h"
 11
 12/* The PCI address space for buffer handling looks like this:
 13 *
 14 * +-u32 wide-------------+
 15 * |                      +
 16 * +-u64 wide------------------------------------+
 17 * +                                             +
 18 * +----------------------+
 19 * | CurrentBufferPtr     + Pointer to current PCI buffer >-+
 20 * +----------------------+                                 |
 21 * | Unused               +                                 |
 22 * +----------------------+                                 |
 23 * | Pitch                + = 188 (bytes)                   |
 24 * +----------------------+                                 |
 25 * | PCI buffer size      + = pitch * number of lines (312) |
 26 * +----------------------+                                 |
 27 * |0| Buf0 Write Offset  +                                 |
 28 * +----------------------+                                 v
 29 * |1| Buf1 Write Offset  +                                 |
 30 * +----------------------+                                 |
 31 * |2| Buf2 Write Offset  +                                 |
 32 * +----------------------+                                 |
 33 * |3| Buf3 Write Offset  +                                 |
 34 * +----------------------+                                 |
 35 * ... More write offsets                                   |
 36 * +---------------------------------------------+          |
 37 * +0| set of ptrs to PCI pagetables             +          |
 38 * +---------------------------------------------+          |
 39 * +1| set of ptrs to PCI pagetables             + <--------+
 40 * +---------------------------------------------+
 41 * +2| set of ptrs to PCI pagetables             +
 42 * +---------------------------------------------+
 43 * +3| set of ptrs to PCI pagetables             + >--+
 44 * +---------------------------------------------+    |
 45 * ... More buffer pointers                           |  +----------------+
 46 *						    +->| pt[0] TS data  |
 47 *						    |  +----------------+
 48 *						    |
 49 *						    |  +----------------+
 50 *						    +->| pt[1] TS data  |
 51 *						    |  +----------------+
 52 *						    | etc
 53 */
 54
 55/* Allocate a new buffer structure and associated PCI space in bytes.
 56 * len must be a multiple of sizeof(u64)
 57 */
 58struct saa7164_buffer *saa7164_buffer_alloc(struct saa7164_port *port,
 59	u32 len)
 60{
 61	struct tmHWStreamParameters *params = &port->hw_streamingparams;
 62	struct saa7164_buffer *buf = NULL;
 63	struct saa7164_dev *dev = port->dev;
 64	int i;
 65
 66	if ((len == 0) || (len >= 65536) || (len % sizeof(u64))) {
 67		log_warn("%s() SAA_ERR_BAD_PARAMETER\n", __func__);
 68		goto ret;
 69	}
 70
 71	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
 72	if (!buf)
 73		goto ret;
 74
 75	buf->idx = -1;
 76	buf->port = port;
 77	buf->flags = SAA7164_BUFFER_FREE;
 78	buf->pos = 0;
 79	buf->actual_size = params->pitch * params->numberoflines;
 80	buf->crc = 0;
 81	/* TODO: arg len is being ignored */
 82	buf->pci_size = SAA7164_PT_ENTRIES * 0x1000;
 83	buf->pt_size = (SAA7164_PT_ENTRIES * sizeof(u64)) + 0x1000;
 84
 85	/* Allocate contiguous memory */
 86	buf->cpu = dma_alloc_coherent(&port->dev->pci->dev, buf->pci_size,
 87				      &buf->dma, GFP_KERNEL);
 88	if (!buf->cpu)
 89		goto fail1;
 90
 91	buf->pt_cpu = dma_alloc_coherent(&port->dev->pci->dev, buf->pt_size,
 92					 &buf->pt_dma, GFP_KERNEL);
 93	if (!buf->pt_cpu)
 94		goto fail2;
 95
 96	/* init the buffers to a known pattern, easier during debugging */
 97	memset(buf->cpu, 0xff, buf->pci_size);
 98	buf->crc = crc32(0, buf->cpu, buf->actual_size);
 99	memset(buf->pt_cpu, 0xff, buf->pt_size);
100
101	dprintk(DBGLVL_BUF, "%s()   allocated buffer @ 0x%p (%d pageptrs)\n",
102		__func__, buf, params->numpagetables);
103	dprintk(DBGLVL_BUF, "  pci_cpu @ 0x%p    dma @ 0x%08lx len = 0x%x\n",
104		buf->cpu, (long)buf->dma, buf->pci_size);
105	dprintk(DBGLVL_BUF, "   pt_cpu @ 0x%p pt_dma @ 0x%08lx len = 0x%x\n",
106		buf->pt_cpu, (long)buf->pt_dma, buf->pt_size);
107
108	/* Format the Page Table Entries to point into the data buffer */
109	for (i = 0 ; i < params->numpagetables; i++) {
110
111		*(buf->pt_cpu + i) = buf->dma + (i * 0x1000); /* TODO */
112		dprintk(DBGLVL_BUF, "    pt[%02d] = 0x%p -> 0x%llx\n",
113			i, buf->pt_cpu, (u64)*(buf->pt_cpu));
114
115	}
116
117	goto ret;
118
119fail2:
120	dma_free_coherent(&port->dev->pci->dev, buf->pci_size, buf->cpu,
121			  buf->dma);
122fail1:
123	kfree(buf);
124
125	buf = NULL;
126ret:
127	return buf;
128}
129
130int saa7164_buffer_dealloc(struct saa7164_buffer *buf)
131{
132	struct saa7164_dev *dev;
133
134	if (!buf || !buf->port)
135		return SAA_ERR_BAD_PARAMETER;
136	dev = buf->port->dev;
137
138	dprintk(DBGLVL_BUF, "%s() deallocating buffer @ 0x%p\n",
139		__func__, buf);
140
141	if (buf->flags != SAA7164_BUFFER_FREE)
142		log_warn(" freeing a non-free buffer\n");
143
144	dma_free_coherent(&dev->pci->dev, buf->pci_size, buf->cpu, buf->dma);
145	dma_free_coherent(&dev->pci->dev, buf->pt_size, buf->pt_cpu,
146			  buf->pt_dma);
147
148	kfree(buf);
149
150	return SAA_OK;
151}
152
153int saa7164_buffer_zero_offsets(struct saa7164_port *port, int i)
154{
155	struct saa7164_dev *dev = port->dev;
156
157	if ((i < 0) || (i >= port->hwcfg.buffercount))
158		return -EINVAL;
159
160	dprintk(DBGLVL_BUF, "%s(idx = %d)\n", __func__, i);
161
162	saa7164_writel(port->bufoffset + (sizeof(u32) * i), 0);
163
164	return 0;
165}
166
167/* Write a buffer into the hardware */
168int saa7164_buffer_activate(struct saa7164_buffer *buf, int i)
169{
170	struct saa7164_port *port = buf->port;
171	struct saa7164_dev *dev = port->dev;
172
173	if ((i < 0) || (i >= port->hwcfg.buffercount))
174		return -EINVAL;
175
176	dprintk(DBGLVL_BUF, "%s(idx = %d)\n", __func__, i);
177
178	buf->idx = i; /* Note of which buffer list index position we occupy */
179	buf->flags = SAA7164_BUFFER_BUSY;
180	buf->pos = 0;
181
182	/* TODO: Review this in light of 32v64 assignments */
183	saa7164_writel(port->bufoffset + (sizeof(u32) * i), 0);
184	saa7164_writel(port->bufptr32h + ((sizeof(u32) * 2) * i), buf->pt_dma);
185	saa7164_writel(port->bufptr32l + ((sizeof(u32) * 2) * i), 0);
186
187	dprintk(DBGLVL_BUF, "	buf[%d] offset 0x%llx (0x%x) buf 0x%llx/%llx (0x%x/%x) nr=%d\n",
188		buf->idx,
189		(u64)port->bufoffset + (i * sizeof(u32)),
190		saa7164_readl(port->bufoffset + (sizeof(u32) * i)),
191		(u64)port->bufptr32h + ((sizeof(u32) * 2) * i),
192		(u64)port->bufptr32l + ((sizeof(u32) * 2) * i),
193		saa7164_readl(port->bufptr32h + ((sizeof(u32) * i) * 2)),
194		saa7164_readl(port->bufptr32l + ((sizeof(u32) * i) * 2)),
195		buf->idx);
196
197	return 0;
198}
199
200int saa7164_buffer_cfg_port(struct saa7164_port *port)
201{
202	struct tmHWStreamParameters *params = &port->hw_streamingparams;
203	struct saa7164_dev *dev = port->dev;
204	struct saa7164_buffer *buf;
205	struct list_head *c, *n;
206	int i = 0;
207
208	dprintk(DBGLVL_BUF, "%s(port=%d)\n", __func__, port->nr);
209
210	saa7164_writel(port->bufcounter, 0);
211	saa7164_writel(port->pitch, params->pitch);
212	saa7164_writel(port->bufsize, params->pitch * params->numberoflines);
213
214	dprintk(DBGLVL_BUF, " configured:\n");
215	dprintk(DBGLVL_BUF, "   lmmio       0x%p\n", dev->lmmio);
216	dprintk(DBGLVL_BUF, "   bufcounter  0x%x = 0x%x\n", port->bufcounter,
217		saa7164_readl(port->bufcounter));
218
219	dprintk(DBGLVL_BUF, "   pitch       0x%x = %d\n", port->pitch,
220		saa7164_readl(port->pitch));
221
222	dprintk(DBGLVL_BUF, "   bufsize     0x%x = %d\n", port->bufsize,
223		saa7164_readl(port->bufsize));
224
225	dprintk(DBGLVL_BUF, "   buffercount = %d\n", port->hwcfg.buffercount);
226	dprintk(DBGLVL_BUF, "   bufoffset = 0x%x\n", port->bufoffset);
227	dprintk(DBGLVL_BUF, "   bufptr32h = 0x%x\n", port->bufptr32h);
228	dprintk(DBGLVL_BUF, "   bufptr32l = 0x%x\n", port->bufptr32l);
229
230	/* Poke the buffers and offsets into PCI space */
231	mutex_lock(&port->dmaqueue_lock);
232	list_for_each_safe(c, n, &port->dmaqueue.list) {
233		buf = list_entry(c, struct saa7164_buffer, list);
234
235		BUG_ON(buf->flags != SAA7164_BUFFER_FREE);
236
237		/* Place the buffer in the h/w queue */
238		saa7164_buffer_activate(buf, i);
239
240		/* Don't exceed the device maximum # bufs */
241		BUG_ON(i > port->hwcfg.buffercount);
242		i++;
243
244	}
245	mutex_unlock(&port->dmaqueue_lock);
246
247	return 0;
248}
249
250struct saa7164_user_buffer *saa7164_buffer_alloc_user(struct saa7164_dev *dev,
251	u32 len)
252{
253	struct saa7164_user_buffer *buf;
254
255	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
256	if (!buf)
257		return NULL;
258
259	buf->data = kzalloc(len, GFP_KERNEL);
260
261	if (!buf->data) {
262		kfree(buf);
263		return NULL;
264	}
265
266	buf->actual_size = len;
267	buf->pos = 0;
268	buf->crc = 0;
269
270	dprintk(DBGLVL_BUF, "%s()   allocated user buffer @ 0x%p\n",
271		__func__, buf);
272
273	return buf;
274}
275
276void saa7164_buffer_dealloc_user(struct saa7164_user_buffer *buf)
277{
278	if (!buf)
279		return;
280
281	kfree(buf->data);
282	buf->data = NULL;
283
284	kfree(buf);
285}