saa7164-buffer.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for the NXP SAA7164 PCIe bridge
*
* Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
*/
#include <linux/slab.h>
#include "saa7164.h"
/* The PCI address space for buffer handling looks like this:
*
* +-u32 wide-------------+
* | +
* +-u64 wide------------------------------------+
* + +
* +----------------------+
* | CurrentBufferPtr + Pointer to current PCI buffer >-+
* +----------------------+ |
* | Unused + |
* +----------------------+ |
* | Pitch + = 188 (bytes) |
* +----------------------+ |
* | PCI buffer size + = pitch * number of lines (312) |
* +----------------------+ |
* |0| Buf0 Write Offset + |
* +----------------------+ v
* |1| Buf1 Write Offset + |
* +----------------------+ |
* |2| Buf2 Write Offset + |
* +----------------------+ |
* |3| Buf3 Write Offset + |
* +----------------------+ |
* ... More write offsets |
* +---------------------------------------------+ |
* +0| set of ptrs to PCI pagetables + |
* +---------------------------------------------+ |
* +1| set of ptrs to PCI pagetables + <--------+
* +---------------------------------------------+
* +2| set of ptrs to PCI pagetables +
* +---------------------------------------------+
* +3| set of ptrs to PCI pagetables + >--+
* +---------------------------------------------+ |
* ... More buffer pointers | +----------------+
* +->| pt[0] TS data |
* | +----------------+
* |
* | +----------------+
* +->| pt[1] TS data |
* | +----------------+
* | etc
*/
void saa7164_buffer_display(struct saa7164_buffer *buf)
{
struct saa7164_dev *dev = buf->port->dev;
int i;
dprintk(DBGLVL_BUF, "%s() buffer @ 0x%p nr=%d\n",
__func__, buf, buf->idx);
dprintk(DBGLVL_BUF, " pci_cpu @ 0x%p dma @ 0x%08llx len = 0x%x\n",
buf->cpu, (long long)buf->dma, buf->pci_size);
dprintk(DBGLVL_BUF, " pt_cpu @ 0x%p pt_dma @ 0x%08llx len = 0x%x\n",
buf->pt_cpu, (long long)buf->pt_dma, buf->pt_size);
/* Format the Page Table Entries to point into the data buffer */
for (i = 0 ; i < SAA7164_PT_ENTRIES; i++) {
dprintk(DBGLVL_BUF, " pt[%02d] = 0x%p -> 0x%llx\n",
i, buf->pt_cpu, (u64)*(buf->pt_cpu));
}
}
/* Allocate a new buffer structure and associated PCI space in bytes.
* len must be a multiple of sizeof(u64)
*/
struct saa7164_buffer *saa7164_buffer_alloc(struct saa7164_port *port,
u32 len)
{
struct tmHWStreamParameters *params = &port->hw_streamingparams;
struct saa7164_buffer *buf = NULL;
struct saa7164_dev *dev = port->dev;
int i;
if ((len == 0) || (len >= 65536) || (len % sizeof(u64))) {
log_warn("%s() SAA_ERR_BAD_PARAMETER\n", __func__);
goto ret;
}
buf = kzalloc(sizeof(*buf), GFP_KERNEL);
if (!buf)
goto ret;
buf->idx = -1;
buf->port = port;
buf->flags = SAA7164_BUFFER_FREE;
buf->pos = 0;
buf->actual_size = params->pitch * params->numberoflines;
buf->crc = 0;
/* TODO: arg len is being ignored */
buf->pci_size = SAA7164_PT_ENTRIES * 0x1000;
buf->pt_size = (SAA7164_PT_ENTRIES * sizeof(u64)) + 0x1000;
/* Allocate contiguous memory */
buf->cpu = dma_alloc_coherent(&port->dev->pci->dev, buf->pci_size,
&buf->dma, GFP_KERNEL);
if (!buf->cpu)
goto fail1;
buf->pt_cpu = dma_alloc_coherent(&port->dev->pci->dev, buf->pt_size,
&buf->pt_dma, GFP_KERNEL);
if (!buf->pt_cpu)
goto fail2;
/* init the buffers to a known pattern, easier during debugging */
memset(buf->cpu, 0xff, buf->pci_size);
buf->crc = crc32(0, buf->cpu, buf->actual_size);
memset(buf->pt_cpu, 0xff, buf->pt_size);
dprintk(DBGLVL_BUF, "%s() allocated buffer @ 0x%p (%d pageptrs)\n",
__func__, buf, params->numpagetables);
dprintk(DBGLVL_BUF, " pci_cpu @ 0x%p dma @ 0x%08lx len = 0x%x\n",
buf->cpu, (long)buf->dma, buf->pci_size);
dprintk(DBGLVL_BUF, " pt_cpu @ 0x%p pt_dma @ 0x%08lx len = 0x%x\n",
buf->pt_cpu, (long)buf->pt_dma, buf->pt_size);
/* Format the Page Table Entries to point into the data buffer */
for (i = 0 ; i < params->numpagetables; i++) {
*(buf->pt_cpu + i) = buf->dma + (i * 0x1000); /* TODO */
dprintk(DBGLVL_BUF, " pt[%02d] = 0x%p -> 0x%llx\n",
i, buf->pt_cpu, (u64)*(buf->pt_cpu));
}
goto ret;
fail2:
dma_free_coherent(&port->dev->pci->dev, buf->pci_size, buf->cpu,
buf->dma);
fail1:
kfree(buf);
buf = NULL;
ret:
return buf;
}
int saa7164_buffer_dealloc(struct saa7164_buffer *buf)
{
struct saa7164_dev *dev;
if (!buf || !buf->port)
return SAA_ERR_BAD_PARAMETER;
dev = buf->port->dev;
dprintk(DBGLVL_BUF, "%s() deallocating buffer @ 0x%p\n",
__func__, buf);
if (buf->flags != SAA7164_BUFFER_FREE)
log_warn(" freeing a non-free buffer\n");
dma_free_coherent(&dev->pci->dev, buf->pci_size, buf->cpu, buf->dma);
dma_free_coherent(&dev->pci->dev, buf->pt_size, buf->pt_cpu,
buf->pt_dma);
kfree(buf);
return SAA_OK;
}
int saa7164_buffer_zero_offsets(struct saa7164_port *port, int i)
{
struct saa7164_dev *dev = port->dev;
if ((i < 0) || (i >= port->hwcfg.buffercount))
return -EINVAL;
dprintk(DBGLVL_BUF, "%s(idx = %d)\n", __func__, i);
saa7164_writel(port->bufoffset + (sizeof(u32) * i), 0);
return 0;
}
/* Write a buffer into the hardware */
int saa7164_buffer_activate(struct saa7164_buffer *buf, int i)
{
struct saa7164_port *port = buf->port;
struct saa7164_dev *dev = port->dev;
if ((i < 0) || (i >= port->hwcfg.buffercount))
return -EINVAL;
dprintk(DBGLVL_BUF, "%s(idx = %d)\n", __func__, i);
buf->idx = i; /* Note of which buffer list index position we occupy */
buf->flags = SAA7164_BUFFER_BUSY;
buf->pos = 0;
/* TODO: Review this in light of 32v64 assignments */
saa7164_writel(port->bufoffset + (sizeof(u32) * i), 0);
saa7164_writel(port->bufptr32h + ((sizeof(u32) * 2) * i), buf->pt_dma);
saa7164_writel(port->bufptr32l + ((sizeof(u32) * 2) * i), 0);
dprintk(DBGLVL_BUF, " buf[%d] offset 0x%llx (0x%x) buf 0x%llx/%llx (0x%x/%x) nr=%d\n",
buf->idx,
(u64)port->bufoffset + (i * sizeof(u32)),
saa7164_readl(port->bufoffset + (sizeof(u32) * i)),
(u64)port->bufptr32h + ((sizeof(u32) * 2) * i),
(u64)port->bufptr32l + ((sizeof(u32) * 2) * i),
saa7164_readl(port->bufptr32h + ((sizeof(u32) * i) * 2)),
saa7164_readl(port->bufptr32l + ((sizeof(u32) * i) * 2)),
buf->idx);
return 0;
}
int saa7164_buffer_cfg_port(struct saa7164_port *port)
{
struct tmHWStreamParameters *params = &port->hw_streamingparams;
struct saa7164_dev *dev = port->dev;
struct saa7164_buffer *buf;
struct list_head *c, *n;
int i = 0;
dprintk(DBGLVL_BUF, "%s(port=%d)\n", __func__, port->nr);
saa7164_writel(port->bufcounter, 0);
saa7164_writel(port->pitch, params->pitch);
saa7164_writel(port->bufsize, params->pitch * params->numberoflines);
dprintk(DBGLVL_BUF, " configured:\n");
dprintk(DBGLVL_BUF, " lmmio 0x%p\n", dev->lmmio);
dprintk(DBGLVL_BUF, " bufcounter 0x%x = 0x%x\n", port->bufcounter,
saa7164_readl(port->bufcounter));
dprintk(DBGLVL_BUF, " pitch 0x%x = %d\n", port->pitch,
saa7164_readl(port->pitch));
dprintk(DBGLVL_BUF, " bufsize 0x%x = %d\n", port->bufsize,
saa7164_readl(port->bufsize));
dprintk(DBGLVL_BUF, " buffercount = %d\n", port->hwcfg.buffercount);
dprintk(DBGLVL_BUF, " bufoffset = 0x%x\n", port->bufoffset);
dprintk(DBGLVL_BUF, " bufptr32h = 0x%x\n", port->bufptr32h);
dprintk(DBGLVL_BUF, " bufptr32l = 0x%x\n", port->bufptr32l);
/* Poke the buffers and offsets into PCI space */
mutex_lock(&port->dmaqueue_lock);
list_for_each_safe(c, n, &port->dmaqueue.list) {
buf = list_entry(c, struct saa7164_buffer, list);
BUG_ON(buf->flags != SAA7164_BUFFER_FREE);
/* Place the buffer in the h/w queue */
saa7164_buffer_activate(buf, i);
/* Don't exceed the device maximum # bufs */
BUG_ON(i > port->hwcfg.buffercount);
i++;
}
mutex_unlock(&port->dmaqueue_lock);
return 0;
}
struct saa7164_user_buffer *saa7164_buffer_alloc_user(struct saa7164_dev *dev,
u32 len)
{
struct saa7164_user_buffer *buf;
buf = kzalloc(sizeof(*buf), GFP_KERNEL);
if (!buf)
return NULL;
buf->data = kzalloc(len, GFP_KERNEL);
if (!buf->data) {
kfree(buf);
return NULL;
}
buf->actual_size = len;
buf->pos = 0;
buf->crc = 0;
dprintk(DBGLVL_BUF, "%s() allocated user buffer @ 0x%p\n",
__func__, buf);
return buf;
}
void saa7164_buffer_dealloc_user(struct saa7164_user_buffer *buf)
{
if (!buf)
return;
kfree(buf->data);
buf->data = NULL;
kfree(buf);
}