Add support for processing the command ring. Command ring is used by the
host to issue channel specific commands to the ep device. Following
commands are supported:
1. Start channel
2. Stop channel
3. Reset channel
Once the device receives the command doorbell interrupt from host, it
executes the command and generates a command completion event to the
host in the primary event ring.
Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
drivers/bus/mhi/ep/main.c | 151 ++++++++++++++++++++++++++++++++++++++
1 file changed, 151 insertions(+)
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index 6378ac5c7e37..4c2ee517832c 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -21,6 +21,7 @@
static DEFINE_IDA(mhi_ep_cntrl_ida);
+static int mhi_ep_create_device(struct mhi_ep_cntrl *mhi_cntrl, u32 ch_id);
static int mhi_ep_destroy_device(struct device *dev, void *data);
static int mhi_ep_send_event(struct mhi_ep_cntrl *mhi_cntrl, u32 ring_idx,
@@ -185,6 +186,156 @@ void mhi_ep_unmap_free(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr, phys_addr_t
mhi_cntrl->free_addr(mhi_cntrl, phys - offset, virt - offset, size);
}
+int mhi_ep_process_cmd_ring(struct mhi_ep_ring *ring, struct mhi_ep_ring_element *el)
+{
+ struct mhi_ep_cntrl *mhi_cntrl = ring->mhi_cntrl;
+ struct device *dev = &mhi_cntrl->mhi_dev->dev;
+ struct mhi_result result = {};
+ struct mhi_ep_chan *mhi_chan;
+ struct mhi_ep_ring *ch_ring;
+ u32 tmp, ch_id;
+ int ret;
+
+ ch_id = MHI_TRE_GET_CMD_CHID(el);
+ mhi_chan = &mhi_cntrl->mhi_chan[ch_id];
+ ch_ring = &mhi_cntrl->mhi_chan[ch_id].ring;
+
+ switch (MHI_TRE_GET_CMD_TYPE(el)) {
+ case MHI_PKT_TYPE_START_CHAN_CMD:
+ dev_dbg(dev, "Received START command for channel (%d)\n", ch_id);
+
+ mutex_lock(&mhi_chan->lock);
+ /* Initialize and configure the corresponding channel ring */
+ if (!ch_ring->started) {
+ ret = mhi_ep_ring_start(mhi_cntrl, ch_ring,
+ (union mhi_ep_ring_ctx *)&mhi_cntrl->ch_ctx_cache[ch_id]);
+ if (ret) {
+ dev_err(dev, "Failed to start ring for channel (%d)\n", ch_id);
+ ret = mhi_ep_send_cmd_comp_event(mhi_cntrl,
+ MHI_EV_CC_UNDEFINED_ERR);
+ if (ret)
+ dev_err(dev, "Error sending completion event (%d)\n",
+ MHI_EV_CC_UNDEFINED_ERR);
+
+ goto err_unlock;
+ }
+ }
+
+ /* Enable DB for the channel */
+ mhi_ep_mmio_enable_chdb_a7(mhi_cntrl, ch_id);
+
+ /* Set channel state to RUNNING */
+ mhi_chan->state = MHI_CH_STATE_RUNNING;
+ tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[ch_id].chcfg);
+ tmp &= ~CHAN_CTX_CHSTATE_MASK;
+ tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_RUNNING);
+ mhi_cntrl->ch_ctx_cache[ch_id].chcfg = cpu_to_le32(tmp);
+
+ ret = mhi_ep_send_cmd_comp_event(mhi_cntrl, MHI_EV_CC_SUCCESS);
+ if (ret) {
+ dev_err(dev, "Error sending command completion event (%d)\n",
+ MHI_EV_CC_SUCCESS);
+ goto err_unlock;
+ }
+
+ mutex_unlock(&mhi_chan->lock);
+
+ /*
+ * Create MHI device only during UL channel start. Since the MHI
+ * channels operate in a pair, we'll associate both UL and DL
+ * channels to the same device.
+ *
+ * We also need to check for mhi_dev != NULL because, the host
+ * will issue START_CHAN command during resume and we don't
+ * destroy the device during suspend.
+ */
+ if (!(ch_id % 2) && !mhi_chan->mhi_dev) {
+ ret = mhi_ep_create_device(mhi_cntrl, ch_id);
+ if (ret) {
+ dev_err(dev, "Error creating device for channel (%d)\n", ch_id);
+ return ret;
+ }
+ }
+
+ break;
+ case MHI_PKT_TYPE_STOP_CHAN_CMD:
+ dev_dbg(dev, "Received STOP command for channel (%d)\n", ch_id);
+ if (!ch_ring->started) {
+ dev_err(dev, "Channel (%d) not opened\n", ch_id);
+ return -ENODEV;
+ }
+
+ mutex_lock(&mhi_chan->lock);
+ /* Disable DB for the channel */
+ mhi_ep_mmio_disable_chdb_a7(mhi_cntrl, ch_id);
+
+ /* Send channel disconnect status to client drivers */
+ result.transaction_status = -ENOTCONN;
+ result.bytes_xferd = 0;
+ mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
+
+ /* Set channel state to STOP */
+ mhi_chan->state = MHI_CH_STATE_STOP;
+ tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[ch_id].chcfg);
+ tmp &= ~CHAN_CTX_CHSTATE_MASK;
+ tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_STOP);
+ mhi_cntrl->ch_ctx_cache[ch_id].chcfg = cpu_to_le32(tmp);
+
+ ret = mhi_ep_send_cmd_comp_event(mhi_cntrl, MHI_EV_CC_SUCCESS);
+ if (ret) {
+ dev_err(dev, "Error sending command completion event (%d)\n",
+ MHI_EV_CC_SUCCESS);
+ goto err_unlock;
+ }
+
+ mutex_unlock(&mhi_chan->lock);
+ break;
+ case MHI_PKT_TYPE_RESET_CHAN_CMD:
+ dev_dbg(dev, "Received STOP command for channel (%d)\n", ch_id);
+ if (!ch_ring->started) {
+ dev_err(dev, "Channel (%d) not opened\n", ch_id);
+ return -ENODEV;
+ }
+
+ mutex_lock(&mhi_chan->lock);
+ /* Stop and reset the transfer ring */
+ mhi_ep_ring_reset(mhi_cntrl, ch_ring);
+
+ /* Send channel disconnect status to client driver */
+ result.transaction_status = -ENOTCONN;
+ result.bytes_xferd = 0;
+ mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
+
+ /* Set channel state to DISABLED */
+ mhi_chan->state = MHI_CH_STATE_DISABLED;
+ tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[ch_id].chcfg);
+ tmp &= ~CHAN_CTX_CHSTATE_MASK;
+ tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_DISABLED);
+ mhi_cntrl->ch_ctx_cache[ch_id].chcfg = cpu_to_le32(tmp);
+
+ ret = mhi_ep_send_cmd_comp_event(mhi_cntrl, MHI_EV_CC_SUCCESS);
+ if (ret) {
+ dev_err(dev, "Error sending command completion event (%d)\n",
+ MHI_EV_CC_SUCCESS);
+ goto err_unlock;
+ }
+
+ mutex_unlock(&mhi_chan->lock);
+ break;
+ default:
+ dev_err(dev, "Invalid command received: %d for channel (%d)\n",
+ MHI_TRE_GET_CMD_TYPE(el), ch_id);
+ return -EINVAL;
+ }
+
+ return 0;
+
+err_unlock:
+ mutex_unlock(&mhi_chan->lock);
+
+ return ret;
+}
+
static int mhi_ep_cache_host_cfg(struct mhi_ep_cntrl *mhi_cntrl)
{
struct device *dev = &mhi_cntrl->mhi_dev->dev;
--
2.25.1
On 2/12/22 12:21 PM, Manivannan Sadhasivam wrote:
> Add support for processing the command ring. Command ring is used by the
> host to issue channel specific commands to the ep device. Following
> commands are supported:
>
> 1. Start channel
> 2. Stop channel
> 3. Reset channel
>
> Once the device receives the command doorbell interrupt from host, it
> executes the command and generates a command completion event to the
> host in the primary event ring.
>
> Signed-off-by: Manivannan Sadhasivam <[email protected]>
I'll let you consider my few comments below, but whether or not you
address them, this looks OK to me.
Reviewed-by: Alex Elder <[email protected]>
> ---
> drivers/bus/mhi/ep/main.c | 151 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 151 insertions(+)
>
> diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
> index 6378ac5c7e37..4c2ee517832c 100644
> --- a/drivers/bus/mhi/ep/main.c
> +++ b/drivers/bus/mhi/ep/main.c
> @@ -21,6 +21,7 @@
>
> static DEFINE_IDA(mhi_ep_cntrl_ida);
>
> +static int mhi_ep_create_device(struct mhi_ep_cntrl *mhi_cntrl, u32 ch_id);
> static int mhi_ep_destroy_device(struct device *dev, void *data);
>
> static int mhi_ep_send_event(struct mhi_ep_cntrl *mhi_cntrl, u32 ring_idx,
> @@ -185,6 +186,156 @@ void mhi_ep_unmap_free(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr, phys_addr_t
> mhi_cntrl->free_addr(mhi_cntrl, phys - offset, virt - offset, size);
> }
>
> +int mhi_ep_process_cmd_ring(struct mhi_ep_ring *ring, struct mhi_ep_ring_element *el)
> +{
> + struct mhi_ep_cntrl *mhi_cntrl = ring->mhi_cntrl;
> + struct device *dev = &mhi_cntrl->mhi_dev->dev;
> + struct mhi_result result = {};
> + struct mhi_ep_chan *mhi_chan;
> + struct mhi_ep_ring *ch_ring;
> + u32 tmp, ch_id;
> + int ret;
> +
> + ch_id = MHI_TRE_GET_CMD_CHID(el);
> + mhi_chan = &mhi_cntrl->mhi_chan[ch_id];
> + ch_ring = &mhi_cntrl->mhi_chan[ch_id].ring;
> +
> + switch (MHI_TRE_GET_CMD_TYPE(el)) {
No MHI_PKT_TYPE_NOOP_CMD?
> + case MHI_PKT_TYPE_START_CHAN_CMD:
> + dev_dbg(dev, "Received START command for channel (%d)\n", ch_id);
> +
> + mutex_lock(&mhi_chan->lock);
> + /* Initialize and configure the corresponding channel ring */
> + if (!ch_ring->started) {
> + ret = mhi_ep_ring_start(mhi_cntrl, ch_ring,
> + (union mhi_ep_ring_ctx *)&mhi_cntrl->ch_ctx_cache[ch_id]);
> + if (ret) {
> + dev_err(dev, "Failed to start ring for channel (%d)\n", ch_id);
> + ret = mhi_ep_send_cmd_comp_event(mhi_cntrl,
> + MHI_EV_CC_UNDEFINED_ERR);
> + if (ret)
> + dev_err(dev, "Error sending completion event (%d)\n",
> + MHI_EV_CC_UNDEFINED_ERR);
Print the value of ret in the above message (not UNDEFINED_ERR).
> +
> + goto err_unlock;
> + }
> + }
> +
> + /* Enable DB for the channel */
> + mhi_ep_mmio_enable_chdb_a7(mhi_cntrl, ch_id);
If an error occurs later, this will be enabled. Is that what
you want? Maybe wait to enable the doorbell until everything
else succeeds.
> +
> + /* Set channel state to RUNNING */
> + mhi_chan->state = MHI_CH_STATE_RUNNING;
> + tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[ch_id].chcfg);
> + tmp &= ~CHAN_CTX_CHSTATE_MASK;
> + tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_RUNNING);
> + mhi_cntrl->ch_ctx_cache[ch_id].chcfg = cpu_to_le32(tmp);
> +
> + ret = mhi_ep_send_cmd_comp_event(mhi_cntrl, MHI_EV_CC_SUCCESS);
> + if (ret) {
> + dev_err(dev, "Error sending command completion event (%d)\n",
> + MHI_EV_CC_SUCCESS);
> + goto err_unlock;
> + }
> +
> + mutex_unlock(&mhi_chan->lock);
> +
> + /*
> + * Create MHI device only during UL channel start. Since the MHI
> + * channels operate in a pair, we'll associate both UL and DL
> + * channels to the same device.
> + *
> + * We also need to check for mhi_dev != NULL because, the host
> + * will issue START_CHAN command during resume and we don't
> + * destroy the device during suspend.
> + */
> + if (!(ch_id % 2) && !mhi_chan->mhi_dev) {
> + ret = mhi_ep_create_device(mhi_cntrl, ch_id);
> + if (ret) {
If this occurs, the host will already have been told the
request completed successfully. Is that a problem that
can/should be avoided?
> + dev_err(dev, "Error creating device for channel (%d)\n", ch_id);
> + return ret;
> + }
> + }
> +
> + break;
> + case MHI_PKT_TYPE_STOP_CHAN_CMD:
> + dev_dbg(dev, "Received STOP command for channel (%d)\n", ch_id);
> + if (!ch_ring->started) {
> + dev_err(dev, "Channel (%d) not opened\n", ch_id);
> + return -ENODEV;
> + }
> +
> + mutex_lock(&mhi_chan->lock);
> + /* Disable DB for the channel */
> + mhi_ep_mmio_disable_chdb_a7(mhi_cntrl, ch_id);
> +
> + /* Send channel disconnect status to client drivers */
> + result.transaction_status = -ENOTCONN;
> + result.bytes_xferd = 0;
> + mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
> +
> + /* Set channel state to STOP */
> + mhi_chan->state = MHI_CH_STATE_STOP;
> + tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[ch_id].chcfg);
> + tmp &= ~CHAN_CTX_CHSTATE_MASK;
> + tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_STOP);
> + mhi_cntrl->ch_ctx_cache[ch_id].chcfg = cpu_to_le32(tmp);
> +
> + ret = mhi_ep_send_cmd_comp_event(mhi_cntrl, MHI_EV_CC_SUCCESS);
> + if (ret) {
> + dev_err(dev, "Error sending command completion event (%d)\n",
> + MHI_EV_CC_SUCCESS);
> + goto err_unlock;
> + }
> +
> + mutex_unlock(&mhi_chan->lock);
> + break;
> + case MHI_PKT_TYPE_RESET_CHAN_CMD:
> + dev_dbg(dev, "Received STOP command for channel (%d)\n", ch_id);
> + if (!ch_ring->started) {
> + dev_err(dev, "Channel (%d) not opened\n", ch_id);
> + return -ENODEV;
> + }
> +
> + mutex_lock(&mhi_chan->lock);
> + /* Stop and reset the transfer ring */
> + mhi_ep_ring_reset(mhi_cntrl, ch_ring);
> +
> + /* Send channel disconnect status to client driver */
> + result.transaction_status = -ENOTCONN;
> + result.bytes_xferd = 0;
> + mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
> +
> + /* Set channel state to DISABLED */
> + mhi_chan->state = MHI_CH_STATE_DISABLED;
> + tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[ch_id].chcfg);
> + tmp &= ~CHAN_CTX_CHSTATE_MASK;
> + tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_DISABLED);
> + mhi_cntrl->ch_ctx_cache[ch_id].chcfg = cpu_to_le32(tmp);
> +
> + ret = mhi_ep_send_cmd_comp_event(mhi_cntrl, MHI_EV_CC_SUCCESS);
> + if (ret) {
> + dev_err(dev, "Error sending command completion event (%d)\n",
> + MHI_EV_CC_SUCCESS);
> + goto err_unlock;
> + }
> +
> + mutex_unlock(&mhi_chan->lock);
> + break;
> + default:
> + dev_err(dev, "Invalid command received: %d for channel (%d)\n",
> + MHI_TRE_GET_CMD_TYPE(el), ch_id);
> + return -EINVAL;
> + }
> +
> + return 0;
> +
> +err_unlock:
> + mutex_unlock(&mhi_chan->lock);
> +
> + return ret;
> +}
> +
> static int mhi_ep_cache_host_cfg(struct mhi_ep_cntrl *mhi_cntrl)
> {
> struct device *dev = &mhi_cntrl->mhi_dev->dev;
On Tue, Feb 15, 2022 at 04:40:01PM -0600, Alex Elder wrote:
> On 2/12/22 12:21 PM, Manivannan Sadhasivam wrote:
> > Add support for processing the command ring. Command ring is used by the
> > host to issue channel specific commands to the ep device. Following
> > commands are supported:
> >
> > 1. Start channel
> > 2. Stop channel
> > 3. Reset channel
> >
> > Once the device receives the command doorbell interrupt from host, it
> > executes the command and generates a command completion event to the
> > host in the primary event ring.
> >
> > Signed-off-by: Manivannan Sadhasivam <[email protected]>
>
> I'll let you consider my few comments below, but whether or not you
> address them, this looks OK to me.
>
> Reviewed-by: Alex Elder <[email protected]>
>
> > ---
> > drivers/bus/mhi/ep/main.c | 151 ++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 151 insertions(+)
> >
> > diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
> > index 6378ac5c7e37..4c2ee517832c 100644
> > --- a/drivers/bus/mhi/ep/main.c
> > +++ b/drivers/bus/mhi/ep/main.c
> > @@ -21,6 +21,7 @@
> > static DEFINE_IDA(mhi_ep_cntrl_ida);
> > +static int mhi_ep_create_device(struct mhi_ep_cntrl *mhi_cntrl, u32 ch_id);
> > static int mhi_ep_destroy_device(struct device *dev, void *data);
> > static int mhi_ep_send_event(struct mhi_ep_cntrl *mhi_cntrl, u32 ring_idx,
> > @@ -185,6 +186,156 @@ void mhi_ep_unmap_free(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr, phys_addr_t
> > mhi_cntrl->free_addr(mhi_cntrl, phys - offset, virt - offset, size);
> > }
> > +int mhi_ep_process_cmd_ring(struct mhi_ep_ring *ring, struct mhi_ep_ring_element *el)
> > +{
> > + struct mhi_ep_cntrl *mhi_cntrl = ring->mhi_cntrl;
> > + struct device *dev = &mhi_cntrl->mhi_dev->dev;
> > + struct mhi_result result = {};
> > + struct mhi_ep_chan *mhi_chan;
> > + struct mhi_ep_ring *ch_ring;
> > + u32 tmp, ch_id;
> > + int ret;
> > +
> > + ch_id = MHI_TRE_GET_CMD_CHID(el);
> > + mhi_chan = &mhi_cntrl->mhi_chan[ch_id];
> > + ch_ring = &mhi_cntrl->mhi_chan[ch_id].ring;
> > +
> > + switch (MHI_TRE_GET_CMD_TYPE(el)) {
>
> No MHI_PKT_TYPE_NOOP_CMD?
>
Not now.
> > + case MHI_PKT_TYPE_START_CHAN_CMD:
> > + dev_dbg(dev, "Received START command for channel (%d)\n", ch_id);
> > +
> > + mutex_lock(&mhi_chan->lock);
> > + /* Initialize and configure the corresponding channel ring */
> > + if (!ch_ring->started) {
> > + ret = mhi_ep_ring_start(mhi_cntrl, ch_ring,
> > + (union mhi_ep_ring_ctx *)&mhi_cntrl->ch_ctx_cache[ch_id]);
> > + if (ret) {
> > + dev_err(dev, "Failed to start ring for channel (%d)\n", ch_id);
> > + ret = mhi_ep_send_cmd_comp_event(mhi_cntrl,
> > + MHI_EV_CC_UNDEFINED_ERR);
> > + if (ret)
> > + dev_err(dev, "Error sending completion event (%d)\n",
> > + MHI_EV_CC_UNDEFINED_ERR);
>
> Print the value of ret in the above message (not UNDEFINED_ERR).
>
> > +
> > + goto err_unlock;
> > + }
> > + }
> > +
> > + /* Enable DB for the channel */
> > + mhi_ep_mmio_enable_chdb_a7(mhi_cntrl, ch_id);
>
> If an error occurs later, this will be enabled. Is that what
> you want? Maybe wait to enable the doorbell until everything
> else succeeds.
>
Makes sense. Will move this to the end.
> > +
> > + /* Set channel state to RUNNING */
> > + mhi_chan->state = MHI_CH_STATE_RUNNING;
> > + tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[ch_id].chcfg);
> > + tmp &= ~CHAN_CTX_CHSTATE_MASK;
> > + tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_RUNNING);
> > + mhi_cntrl->ch_ctx_cache[ch_id].chcfg = cpu_to_le32(tmp);
> > +
> > + ret = mhi_ep_send_cmd_comp_event(mhi_cntrl, MHI_EV_CC_SUCCESS);
> > + if (ret) {
> > + dev_err(dev, "Error sending command completion event (%d)\n",
> > + MHI_EV_CC_SUCCESS);
> > + goto err_unlock;
> > + }
> > +
> > + mutex_unlock(&mhi_chan->lock);
> > +
> > + /*
> > + * Create MHI device only during UL channel start. Since the MHI
> > + * channels operate in a pair, we'll associate both UL and DL
> > + * channels to the same device.
> > + *
> > + * We also need to check for mhi_dev != NULL because, the host
> > + * will issue START_CHAN command during resume and we don't
> > + * destroy the device during suspend.
> > + */
> > + if (!(ch_id % 2) && !mhi_chan->mhi_dev) {
> > + ret = mhi_ep_create_device(mhi_cntrl, ch_id);
> > + if (ret) {
>
> If this occurs, the host will already have been told the
> request completed successfully. Is that a problem that
> can/should be avoided?
>
This should result in SYSERR. Will handle.
Thanks,
Mani