When the device returns used buffers, it should refer to the descriptor
that is the head of the descriptor chain for that buffer. Confirm this
to be the case by tracking the head of descriptor chains that have been
made available to the device.
Signed-off-by: Andrew Scull <ascull@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
The shared descriptors should only be written by the guest driver,
however, the device is still able to overwrite and corrupt them.
Maintain a private shadow copy of the descriptors for the driver to
use for state tracking, removing the need to read from the shared
descriptors.
Signed-off-by: Andrew Scull <ascull@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Move the logic for attaching a descriptor to its own function.
Signed-off-by: Andrew Scull <ascull@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
The variables `total_sg` and `descs_used` have the same value. Replace
the few uses of `total_sg` with `descs_used` to simplify the situation.
Signed-off-by: Andrew Scull <ascull@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
At present dm/device.h includes the linux-compatible features. This
requires including linux/compat.h which in turn includes a lot of headers.
One of these is malloc.h which we thus end up including in every file in
U-Boot. Apart from the inefficiency of this, it is problematic for sandbox
which needs to use the system malloc() in some files.
Move the compatibility features into a separate header file.
Signed-off-by: Simon Glass <sjg@chromium.org>
This adds support for managing virtual queue/ring, the channel
for high performance I/O between host and guest.
Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
