mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 19:00:25 +00:00
f220df66f6
This patch adds an example MSU buffer "sink", which consumes trace data from MSC buffers. Functionally, it acts similarly to "multi" mode with automatic window switching. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20190705141425.19894-3-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
116 lines
2.4 KiB
C
116 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* An example software sink buffer for Intel TH MSU.
|
|
*
|
|
* Copyright (C) 2019 Intel Corporation.
|
|
*/
|
|
|
|
#include <linux/intel_th.h>
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/device.h>
|
|
#include <linux/dma-mapping.h>
|
|
|
|
#define MAX_SGTS 16
|
|
|
|
struct msu_sink_private {
|
|
struct device *dev;
|
|
struct sg_table **sgts;
|
|
unsigned int nr_sgts;
|
|
};
|
|
|
|
static void *msu_sink_assign(struct device *dev, int *mode)
|
|
{
|
|
struct msu_sink_private *priv;
|
|
|
|
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
|
|
if (!priv)
|
|
return NULL;
|
|
|
|
priv->sgts = kcalloc(MAX_SGTS, sizeof(void *), GFP_KERNEL);
|
|
if (!priv->sgts) {
|
|
kfree(priv);
|
|
return NULL;
|
|
}
|
|
|
|
priv->dev = dev;
|
|
*mode = MSC_MODE_MULTI;
|
|
|
|
return priv;
|
|
}
|
|
|
|
static void msu_sink_unassign(void *data)
|
|
{
|
|
struct msu_sink_private *priv = data;
|
|
|
|
kfree(priv->sgts);
|
|
kfree(priv);
|
|
}
|
|
|
|
/* See also: msc.c: __msc_buffer_win_alloc() */
|
|
static int msu_sink_alloc_window(void *data, struct sg_table **sgt, size_t size)
|
|
{
|
|
struct msu_sink_private *priv = data;
|
|
unsigned int nents;
|
|
struct scatterlist *sg_ptr;
|
|
void *block;
|
|
int ret, i;
|
|
|
|
if (priv->nr_sgts == MAX_SGTS)
|
|
return -ENOMEM;
|
|
|
|
nents = DIV_ROUND_UP(size, PAGE_SIZE);
|
|
|
|
ret = sg_alloc_table(*sgt, nents, GFP_KERNEL);
|
|
if (ret)
|
|
return -ENOMEM;
|
|
|
|
priv->sgts[priv->nr_sgts++] = *sgt;
|
|
|
|
for_each_sg((*sgt)->sgl, sg_ptr, nents, i) {
|
|
block = dma_alloc_coherent(priv->dev->parent->parent,
|
|
PAGE_SIZE, &sg_dma_address(sg_ptr),
|
|
GFP_KERNEL);
|
|
sg_set_buf(sg_ptr, block, PAGE_SIZE);
|
|
}
|
|
|
|
return nents;
|
|
}
|
|
|
|
/* See also: msc.c: __msc_buffer_win_free() */
|
|
static void msu_sink_free_window(void *data, struct sg_table *sgt)
|
|
{
|
|
struct msu_sink_private *priv = data;
|
|
struct scatterlist *sg_ptr;
|
|
int i;
|
|
|
|
for_each_sg(sgt->sgl, sg_ptr, sgt->nents, i) {
|
|
dma_free_coherent(priv->dev->parent->parent, PAGE_SIZE,
|
|
sg_virt(sg_ptr), sg_dma_address(sg_ptr));
|
|
}
|
|
|
|
sg_free_table(sgt);
|
|
priv->nr_sgts--;
|
|
}
|
|
|
|
static int msu_sink_ready(void *data, struct sg_table *sgt, size_t bytes)
|
|
{
|
|
struct msu_sink_private *priv = data;
|
|
|
|
intel_th_msc_window_unlock(priv->dev, sgt);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct msu_buffer sink_mbuf = {
|
|
.name = "sink",
|
|
.assign = msu_sink_assign,
|
|
.unassign = msu_sink_unassign,
|
|
.alloc_window = msu_sink_alloc_window,
|
|
.free_window = msu_sink_free_window,
|
|
.ready = msu_sink_ready,
|
|
};
|
|
|
|
module_intel_th_msu_buffer(sink_mbuf);
|
|
|
|
MODULE_LICENSE("GPL v2");
|