accel/qaic: Add fifo queued debugfs

When debugging functional issues with workload input processing, it is
useful to know if requests are backing up in the fifo, or perhaps
getting stuck elsewhere. To answer the question of how many requests are
in the fifo, implement a "queued" debugfs entry per-dbc that returns the
number of pending requests when read.

Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Carl Vanderlip <quic_carlv@quicinc.com>
Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>
Reviewed-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240322175730.3855440-4-quic_jhugo@quicinc.com

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/accel/qaic/qaic_data.c b/drivers/accel/qaic/qaic_data.c
index 2459fe4a3f95..e86e71c1cdd8 100644
--- a/drivers/accel/qaic/qaic_data.c
+++ b/drivers/accel/qaic/qaic_data.c
@@ -1981,3 +1981,12 @@ void release_dbc(struct qaic_device *qdev, u32 dbc_id)
 	dbc->in_use = false;
 	wake_up(&dbc->dbc_release);
 }
+
+void qaic_data_get_fifo_info(struct dma_bridge_chan *dbc, u32 *head, u32 *tail)
+{
+	if (!dbc || !head || !tail)
+		return;
+
+	*head = readl(dbc->dbc_base + REQHP_OFF);
+	*tail = readl(dbc->dbc_base + REQTP_OFF);
+}