This patch uses the GPU cgroup charge/uncharge APIs to charge buffers
allocated by any DMA-BUF exporter that exports a buffer with a GPU cgroup
device association.
By doing so, it becomes possible to track who allocated/exported a
DMA-BUF even after the allocating process drops all references to a
buffer.
Originally-by: Hridya Valsaraju <hridya@xxxxxxxxxx>
Signed-off-by: T.J. Mercier <tjmercier@xxxxxxxxxx>
---
v4 changes
Fix uninitialized return code error for dmabuf_try_charge error case.
v3 changes
Use more common dual author commit message format per John Stultz.
v2 changes
Move dma-buf cgroup charging/uncharging from a dma_buf_op defined by
every heap to a single dma-buf function for all heaps per Daniel Vetter and
Christian König.
---
drivers/dma-buf/dma-buf.c | 58 +++++++++++++++++++++++++++++++++++++++
include/linux/dma-buf.h | 20 ++++++++++++--
2 files changed, 76 insertions(+), 2 deletions(-)
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 602b12d7470d..1ee5c60d3d6d 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -56,6 +56,53 @@ static char *dmabuffs_dname(struct dentry *dentry, char *buffer, int buflen)
dentry->d_name.name, ret > 0 ? name : "");
}
+#ifdef CONFIG_CGROUP_GPU
+static inline struct gpucg_device *
+exp_info_gpucg_dev(const struct dma_buf_export_info *exp_info)
+{
+ return exp_info->gpucg_dev;
+}
+
+static int dmabuf_try_charge(struct dma_buf *dmabuf,
+ struct gpucg_device *gpucg_dev)
+{
+ int ret;
+
+ dmabuf->gpucg = gpucg_get(current);
+ dmabuf->gpucg_dev = gpucg_dev;
+
+ ret = gpucg_try_charge(dmabuf->gpucg, dmabuf->gpucg_dev, dmabuf->size);
+ if (ret) {
+ gpucg_put(dmabuf->gpucg);
+ dmabuf->gpucg = NULL;
+ dmabuf->gpucg_dev = NULL;
+ }
+ return ret;
+}
+
+static void dmabuf_uncharge(struct dma_buf *dmabuf)
+{
+ if (dmabuf->gpucg && dmabuf->gpucg_dev) {
+ gpucg_uncharge(dmabuf->gpucg, dmabuf->gpucg_dev, dmabuf->size);
+ gpucg_put(dmabuf->gpucg);
+ }
+}
+#else /* CONFIG_CGROUP_GPU */
+static inline struct gpucg_device *exp_info_gpucg_dev(
+const struct dma_buf_export_info *exp_info)
+{
+ return NULL;
+}
+
+static inline int dmabuf_try_charge(struct dma_buf *dmabuf,
+ struct gpucg_device *gpucg_dev))
+{
+ return 0;
+}
+
+static inline void dmabuf_uncharge(struct dma_buf *dmabuf) {}
+#endif /* CONFIG_CGROUP_GPU */
+
static void dma_buf_release(struct dentry *dentry)
{
struct dma_buf *dmabuf;
@@ -79,6 +126,8 @@ static void dma_buf_release(struct dentry *dentry)
if (dmabuf->resv == (struct dma_resv *)&dmabuf[1])
dma_resv_fini(dmabuf->resv);
+ dmabuf_uncharge(dmabuf);
+
WARN_ON(!list_empty(&dmabuf->attachments));
module_put(dmabuf->owner);
kfree(dmabuf->name);
@@ -484,6 +533,7 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
{
struct dma_buf *dmabuf;
struct dma_resv *resv = exp_info->resv;
+ struct gpucg_device *gpucg_dev = exp_info_gpucg_dev(exp_info);
struct file *file;
size_t alloc_size = sizeof(struct dma_buf);
int ret;
@@ -534,6 +584,12 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
}
dmabuf->resv = resv;
+ if (gpucg_dev) {
+ ret = dmabuf_try_charge(dmabuf, gpucg_dev);
+ if (ret)
+ goto err_charge;
+ }
+
file = dma_buf_getfile(dmabuf, exp_info->flags);
if (IS_ERR(file)) {
ret = PTR_ERR(file);
@@ -565,6 +621,8 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
file->f_path.dentry->d_fsdata = NULL;
fput(file);
err_dmabuf:
+ dmabuf_uncharge(dmabuf);
+err_charge:
kfree(dmabuf);
err_module:
module_put(exp_info->owner);
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 7ab50076e7a6..742f29c3daaf 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -13,6 +13,7 @@
#ifndef __DMA_BUF_H__
#define __DMA_BUF_H__
+#include <linux/cgroup_gpu.h>
#include <linux/dma-buf-map.h>
#include <linux/file.h>
#include <linux/err.h>
@@ -303,7 +304,7 @@ struct dma_buf {
/**
* @size:
*
- * Size of the buffer; invariant over the lifetime of the buffer.
+ * Size of the buffer in bytes; invariant over the lifetime of the buffer.
*/
size_t size;
@@ -453,6 +454,17 @@ struct dma_buf {
struct dma_buf *dmabuf;
} *sysfs_entry;
#endif
+
+#ifdef CONFIG_CGROUP_GPU
+ /** @gpucg: Pointer to the cgroup this buffer currently belongs to. */
+ struct gpucg *gpucg;
+
+ /** @gpucg_dev:
+ *
+ * Pointer to the cgroup GPU device whence this buffer originates.
+ */
+ struct gpucg_device *gpucg_dev;
+#endif
};
/**
@@ -529,9 +541,10 @@ struct dma_buf_attachment {
* @exp_name: name of the exporter - useful for debugging.
* @owner: pointer to exporter module - used for refcounting kernel module
* @ops: Attach allocator-defined dma buf ops to the new buffer
- * @size: Size of the buffer - invariant over the lifetime of the buffer
+ * @size: Size of the buffer in bytes - invariant over the lifetime of the buffer
* @flags: mode flags for the file
* @resv: reservation-object, NULL to allocate default one
+ * @gpucg_dev: pointer to the gpu cgroup device this buffer belongs to
* @priv: Attach private data of allocator to this buffer
*
* This structure holds the information required to export the buffer. Used
@@ -544,6 +557,9 @@ struct dma_buf_export_info {
size_t size;
int flags;
struct dma_resv *resv;
+#ifdef CONFIG_CGROUP_GPU
+ struct gpucg_device *gpucg_dev;
+#endif
void *priv;
};
--
2.35.1.1021.g381101b075-goog
