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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/hwtracing/intel_th/msu-sink.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/hwtracing/intel_th/msu-sink.c')
-rw-r--r--drivers/hwtracing/intel_th/msu-sink.c119
1 files changed, 119 insertions, 0 deletions
diff --git a/drivers/hwtracing/intel_th/msu-sink.c b/drivers/hwtracing/intel_th/msu-sink.c
new file mode 100644
index 000000000..891b28ea2
--- /dev/null
+++ b/drivers/hwtracing/intel_th/msu-sink.c
@@ -0,0 +1,119 @@
+// 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);
+ if (!block)
+ return -ENOMEM;
+
+ 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");