[char-misc-next 08/12] mei: hw: add dma ring control block

[Tomas Winkler]

The DMA ring control block contains write and read
indices for host and device circular buffers.

Signed-off-by: Tomas Winkler <tomas.wink...@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usys...@intel.com>
---
 drivers/misc/mei/dma-ring.c | 21 +++++++++++++++++++++
 drivers/misc/mei/hbm.c      |  2 ++
 drivers/misc/mei/hw.h       | 23 +++++++++++++++++++++++
 drivers/misc/mei/mei_dev.h  |  1 +
 4 files changed, 47 insertions(+)

diff --git a/drivers/misc/mei/dma-ring.c b/drivers/misc/mei/dma-ring.c
index 368012116196..70901319534e 100644
--- a/drivers/misc/mei/dma-ring.c
+++ b/drivers/misc/mei/dma-ring.c
@@ -101,3 +101,24 @@ bool mei_dma_ring_is_allocated(struct mei_device *dev)
 {
        return !!dev->dr_dscr[DMA_DSCR_HOST].vaddr;
 }
+
+static inline
+struct hbm_dma_ring_ctrl *mei_dma_ring_ctrl(struct mei_device *dev)
+{
+       return (struct hbm_dma_ring_ctrl *)dev->dr_dscr[DMA_DSCR_CTRL].vaddr;
+}
+
+/**
+ * mei_dma_ring_reset - reset the dma control block
+ *
+ * @dev: mei device
+ */
+void mei_dma_ring_reset(struct mei_device *dev)
+{
+       struct hbm_dma_ring_ctrl *ctrl = mei_dma_ring_ctrl(dev);
+
+       if (!ctrl)
+               return;
+
+       memset(ctrl, 0, sizeof(*ctrl));
+}
diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index a3cdffb9ef62..f15d44bda28e 100644
--- a/drivers/misc/mei/hbm.c
+++ b/drivers/misc/mei/hbm.c
@@ -324,6 +324,8 @@ static int mei_hbm_dma_setup_req(struct mei_device *dev)
                req.dma_dscr[i].size = dev->dr_dscr[i].size;
        }
 
+       mei_dma_ring_reset(dev);
+
        ret = mei_hbm_write_message(dev, &mei_hdr, &req);
        if (ret) {
                dev_err(dev->dev, "dma setup request write failed: ret = %d.\n",
diff --git a/drivers/misc/mei/hw.h b/drivers/misc/mei/hw.h
index 65655925791a..4f09bbcdbc2a 100644
--- a/drivers/misc/mei/hw.h
+++ b/drivers/misc/mei/hw.h
@@ -512,4 +512,27 @@ struct hbm_dma_setup_response {
        u8 reserved[2];
 } __packed;
 
+/**
+ * struct mei_dma_ring_ctrl - dma ring control block
+ *
+ * @hbuf_wr_idx: host circular buffer write index in slots
+ * @reserved1: reserved for alignment
+ * @hbuf_rd_idx: host circular buffer read index in slots
+ * @reserved2: reserved for alignment
+ * @dbuf_wr_idx: device circular buffer write index in slots
+ * @reserved3: reserved for alignment
+ * @dbuf_rd_idx: device circular buffer read index in slots
+ * @reserved4: reserved for alignment
+ */
+struct hbm_dma_ring_ctrl {
+       u32 hbuf_wr_idx;
+       u32 reserved1;
+       u32 hbuf_rd_idx;
+       u32 reserved2;
+       u32 dbuf_wr_idx;
+       u32 reserved3;
+       u32 dbuf_rd_idx;
+       u32 reserved4;
+} __packed;
+
 #endif
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index a6796e3f712b..033b5eff8e59 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -597,6 +597,7 @@ void mei_cancel_work(struct mei_device *dev);
 int mei_dmam_ring_alloc(struct mei_device *dev);
 void mei_dmam_ring_free(struct mei_device *dev);
 bool mei_dma_ring_is_allocated(struct mei_device *dev);
+void mei_dma_ring_reset(struct mei_device *dev);
 
 /*
  *  MEI interrupt functions prototype
-- 
2.14.4