Re: [PATCH v6 13/20] firmware: arm_scmi: refactor in preparation to support per-protocol channels
From: Jonathan Cameron
Date: Mon Mar 05 2018 - 09:36:23 EST
On Fri, 23 Feb 2018 16:23:43 +0000
Sudeep Holla <sudeep.holla@xxxxxxx> wrote:
> In order to support per-protocol channels if available, we need to
> factor out all the mailbox channel information(Tx/Rx payload and
> channel handle) out of the main SCMI instance information structure.
>
> This patch refactors the existing channel information into a separate
> chan_info structure.
>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
A little odd to present a series to mainline that does a fairly important
refactor mid way through. Why not push this down to the start and always support
the separate chan_info structure?
> ---
> drivers/firmware/arm_scmi/driver.c | 90 ++++++++++++++++++++++++--------------
> 1 file changed, 56 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
> index e6698629e15a..a9e3f4c46b78 100644
> --- a/drivers/firmware/arm_scmi/driver.c
> +++ b/drivers/firmware/arm_scmi/driver.c
> @@ -102,6 +102,22 @@ struct scmi_desc {
> };
>
> /**
> + * struct scmi_chan_info - Structure representing a SCMI channel informfation
> + *
> + * @cl: Mailbox Client
> + * @chan: Transmit/Receive mailbox channel
> + * @payload: Transmit/Receive mailbox channel payload area
> + * @dev: Reference to device in the SCMI hierarchy corresponding to this
> + * channel
> + */
> +struct scmi_chan_info {
> + struct mbox_client cl;
> + struct mbox_chan *chan;
> + void __iomem *payload;
> + struct device *dev;
> +};
> +
> +/**
> * struct scmi_info - Structure representing a SCMI instance
> *
> * @dev: Device pointer
> @@ -109,10 +125,8 @@ struct scmi_desc {
> * @handle: Instance of SCMI handle to send to clients
> * @version: SCMI revision information containing protocol version,
> * implementation version and (sub-)vendor identification.
> - * @cl: Mailbox Client
> - * @tx_chan: Transmit mailbox channel
> - * @tx_payload: Transmit mailbox channel payload area
> * @minfo: Message info
> + * @tx_cinfo: Reference to SCMI channel information
> * @protocols_imp: list of protocols implemented, currently maximum of
> * MAX_PROTOCOLS_IMP elements allocated by the base protocol
> * @node: list head
> @@ -123,16 +137,14 @@ struct scmi_info {
> const struct scmi_desc *desc;
> struct scmi_revision_info version;
> struct scmi_handle handle;
> - struct mbox_client cl;
> - struct mbox_chan *tx_chan;
> - void __iomem *tx_payload;
> struct scmi_xfers_info minfo;
> + struct scmi_chan_info *tx_cinfo;
> u8 *protocols_imp;
> struct list_head node;
> int users;
> };
>
> -#define client_to_scmi_info(c) container_of(c, struct scmi_info, cl)
> +#define client_to_scmi_chan_info(c) container_of(c, struct scmi_chan_info, cl)
> #define handle_to_scmi_info(h) container_of(h, struct scmi_info, handle)
>
> /*
> @@ -215,10 +227,11 @@ static void scmi_rx_callback(struct mbox_client *cl, void *m)
> {
> u16 xfer_id;
> struct scmi_xfer *xfer;
> - struct scmi_info *info = client_to_scmi_info(cl);
> + struct scmi_chan_info *cinfo = client_to_scmi_chan_info(cl);
> + struct device *dev = cinfo->dev;
> + struct scmi_info *info = dev_get_drvdata(dev);
> struct scmi_xfers_info *minfo = &info->minfo;
> - struct device *dev = info->dev;
> - struct scmi_shared_mem __iomem *mem = info->tx_payload;
> + struct scmi_shared_mem __iomem *mem = cinfo->payload;
>
> xfer_id = MSG_XTRACT_TOKEN(ioread32(&mem->msg_header));
>
> @@ -269,8 +282,8 @@ static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
> static void scmi_tx_prepare(struct mbox_client *cl, void *m)
> {
> struct scmi_xfer *t = m;
> - struct scmi_info *info = client_to_scmi_info(cl);
> - struct scmi_shared_mem __iomem *mem = info->tx_payload;
> + struct scmi_chan_info *cinfo = client_to_scmi_chan_info(cl);
> + struct scmi_shared_mem __iomem *mem = cinfo->payload;
>
> /* Mark channel busy + clear error */
> iowrite32(0x0, &mem->channel_status);
> @@ -349,27 +362,27 @@ void scmi_one_xfer_put(const struct scmi_handle *handle, struct scmi_xfer *xfer)
> }
>
> static bool
> -scmi_xfer_poll_done(const struct scmi_info *info, struct scmi_xfer *xfer)
> +scmi_xfer_poll_done(const struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
> {
> - struct scmi_shared_mem *mem = info->tx_payload;
> - u16 xfer_id = MSG_XTRACT_TOKEN(le32_to_cpu(mem->msg_header));
> + struct scmi_shared_mem __iomem *mem = cinfo->payload;
> + u16 xfer_id = MSG_XTRACT_TOKEN(ioread32(&mem->msg_header));
>
> if (xfer->hdr.seq != xfer_id)
> return false;
>
> - return le32_to_cpu(mem->channel_status) &
> + return ioread32(&mem->channel_status) &
> (SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR |
> SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE);
> }
>
> #define SCMI_MAX_POLL_TO_NS (100 * NSEC_PER_USEC)
>
> -static bool scmi_xfer_done_no_timeout(const struct scmi_info *info,
> +static bool scmi_xfer_done_no_timeout(const struct scmi_chan_info *cinfo,
> struct scmi_xfer *xfer, ktime_t stop)
> {
> ktime_t __cur = ktime_get();
>
> - return scmi_xfer_poll_done(info, xfer) || ktime_after(__cur, stop);
> + return scmi_xfer_poll_done(cinfo, xfer) || ktime_after(__cur, stop);
> }
>
> /**
> @@ -388,8 +401,9 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
> int timeout;
> struct scmi_info *info = handle_to_scmi_info(handle);
> struct device *dev = info->dev;
> + struct scmi_chan_info *cinfo = info->tx_cinfo;
>
> - ret = mbox_send_message(info->tx_chan, xfer);
> + ret = mbox_send_message(cinfo->chan, xfer);
> if (ret < 0) {
> dev_dbg(dev, "mbox send fail %d\n", ret);
> return ret;
> @@ -401,10 +415,10 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
> if (xfer->hdr.poll_completion) {
> ktime_t stop = ktime_add_ns(ktime_get(), SCMI_MAX_POLL_TO_NS);
>
> - spin_until_cond(scmi_xfer_done_no_timeout(info, xfer, stop));
> + spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop));
>
> if (ktime_before(ktime_get(), stop))
> - scmi_fetch_response(xfer, info->tx_payload);
> + scmi_fetch_response(xfer, cinfo->payload);
> else
> ret = -ETIMEDOUT;
> } else {
> @@ -426,7 +440,7 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
> * Unfortunately, we have to kick the mailbox framework after we have
> * received our message.
> */
> - mbox_client_txdone(info->tx_chan, ret);
> + mbox_client_txdone(cinfo->chan, ret);
>
> return ret;
> }
> @@ -654,11 +668,11 @@ static int scmi_mailbox_check(struct device_node *np)
> return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells", 0, &arg);
> }
>
> -static int scmi_mbox_free_channel(struct scmi_info *info)
> +static int scmi_mbox_free_channel(struct scmi_chan_info *cinfo)
> {
> - if (!IS_ERR_OR_NULL(info->tx_chan)) {
> - mbox_free_channel(info->tx_chan);
> - info->tx_chan = NULL;
> + if (!IS_ERR_OR_NULL(cinfo->chan)) {
> + mbox_free_channel(cinfo->chan);
> + cinfo->chan = NULL;
> }
>
> return 0;
> @@ -678,7 +692,7 @@ static int scmi_remove(struct platform_device *pdev)
>
> if (!ret)
> /* Safe to free channels since no more users */
> - return scmi_mbox_free_channel(info);
> + return scmi_mbox_free_channel(info->tx_cinfo);
>
> return ret;
> }
> @@ -690,9 +704,17 @@ static inline int scmi_mbox_chan_setup(struct scmi_info *info)
> resource_size_t size;
> struct device *dev = info->dev;
> struct device_node *shmem, *np = dev->of_node;
> + struct scmi_chan_info *cinfo;
> struct mbox_client *cl;
>
> - cl = &info->cl;
> + cinfo = devm_kzalloc(info->dev, sizeof(*cinfo), GFP_KERNEL);
> + if (!cinfo)
> + return -ENOMEM;
> +
> + info->tx_cinfo = cinfo;
> + cinfo->dev = dev;
> +
> + cl = &cinfo->cl;
> cl->dev = dev;
> cl->rx_callback = scmi_rx_callback;
> cl->tx_prepare = scmi_tx_prepare;
> @@ -708,16 +730,16 @@ static inline int scmi_mbox_chan_setup(struct scmi_info *info)
> }
>
> size = resource_size(&res);
> - info->tx_payload = devm_ioremap(dev, res.start, size);
> - if (!info->tx_payload) {
> + cinfo->payload = devm_ioremap(info->dev, res.start, size);
> + if (!cinfo->payload) {
> dev_err(dev, "failed to ioremap SCMI Tx payload\n");
> return -EADDRNOTAVAIL;
> }
>
> /* Transmit channel is first entry i.e. index 0 */
> - info->tx_chan = mbox_request_channel(cl, 0);
> - if (IS_ERR(info->tx_chan)) {
> - ret = PTR_ERR(info->tx_chan);
> + cinfo->chan = mbox_request_channel(cl, 0);
> + if (IS_ERR(cinfo->chan)) {
> + ret = PTR_ERR(cinfo->chan);
> if (ret != -EPROBE_DEFER)
> dev_err(dev, "failed to request SCMI Tx mailbox\n");
> return ret;
> @@ -785,7 +807,7 @@ static int scmi_probe(struct platform_device *pdev)
> ret = scmi_base_protocol_init(handle);
> if (ret) {
> dev_err(dev, "unable to communicate with SCMI(%d)\n", ret);
> - scmi_mbox_free_channel(info);
> + scmi_mbox_free_channel(info->tx_cinfo);
> return ret;
> }
>