diff options
| -rw-r--r-- | drivers/firmware/arm_scmi/Makefile | 3 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/common.h | 71 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/driver.c | 251 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/mailbox.c | 184 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/shmem.c | 83 |
5 files changed, 373 insertions, 219 deletions
diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile index 5f298f00a82e..6694d0d908d6 100644 --- a/drivers/firmware/arm_scmi/Makefile +++ b/drivers/firmware/arm_scmi/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only -obj-y = scmi-bus.o scmi-driver.o scmi-protocols.o +obj-y = scmi-bus.o scmi-driver.o scmi-protocols.o scmi-transport.o scmi-bus-y = bus.o scmi-driver-y = driver.o +scmi-transport-y = mailbox.o shmem.o scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o obj-$(CONFIG_ARM_SCMI_POWER_DOMAIN) += scmi_pm_domain.o diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index 934b5a23f10b..5ac06469b01c 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -153,3 +153,74 @@ void scmi_setup_protocol_implemented(const struct scmi_handle *handle, u8 *prot_imp); int scmi_base_protocol_init(struct scmi_handle *h); + +/* SCMI Transport */ +/** + * struct scmi_chan_info - Structure representing a SCMI channel information + * + * @dev: Reference to device in the SCMI hierarchy corresponding to this + * channel + * @handle: Pointer to SCMI entity handle + * @transport_info: Transport layer related information + */ +struct scmi_chan_info { + struct device *dev; + struct scmi_handle *handle; + void *transport_info; +}; + +/** + * struct scmi_transport_ops - Structure representing a SCMI transport ops + * + * @chan_available: Callback to check if channel is available or not + * @chan_setup: Callback to allocate and setup a channel + * @chan_free: Callback to free a channel + * @send_message: Callback to send a message + * @mark_txdone: Callback to mark tx as done + * @fetch_response: Callback to fetch response + * @poll_done: Callback to poll transfer status + */ +struct scmi_transport_ops { + bool (*chan_available)(struct device *dev, int idx); + int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev, + bool tx); + int (*chan_free)(int id, void *p, void *data); + int (*send_message)(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer); + void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret); + void (*fetch_response)(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer); + bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); +}; + +/** + * struct scmi_desc - Description of SoC integration + * + * @ops: Pointer to the transport specific ops structure + * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds) + * @max_msg: Maximum number of messages that can be pending + * simultaneously in the system + * @max_msg_size: Maximum size of data per message that can be handled. + */ +struct scmi_desc { + struct scmi_transport_ops *ops; + int max_rx_timeout_ms; + int max_msg; + int max_msg_size; +}; + +extern const struct scmi_desc scmi_mailbox_desc; + +void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr); +void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id); + +/* shmem related declarations */ +struct scmi_shared_mem; + +void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem, + struct scmi_xfer *xfer); +u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem); +void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem, + struct scmi_xfer *xfer); +bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem, + struct scmi_xfer *xfer); diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 716423063b14..dbec767222e9 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -19,12 +19,10 @@ #include <linux/io.h> #include <linux/kernel.h> #include <linux/ktime.h> -#include <linux/mailbox_client.h> #include <linux/module.h> #include <linux/of_address.h> #include <linux/of_device.h> #include <linux/processor.h> -#include <linux/semaphore.h> #include <linux/slab.h> #include "common.h" @@ -70,38 +68,6 @@ struct scmi_xfers_info { }; /** - * struct scmi_desc - Description of SoC integration - * - * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds) - * @max_msg: Maximum number of messages that can be pending - * simultaneously in the system - * @max_msg_size: Maximum size of data per message that can be handled. - */ -struct scmi_desc { - int max_rx_timeout_ms; - int max_msg; - int max_msg_size; -}; - -/** - * struct scmi_chan_info - Structure representing a SCMI channel information - * - * @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 - * @handle: Pointer to SCMI entity handle - */ -struct scmi_chan_info { - struct mbox_client cl; - struct mbox_chan *chan; - void __iomem *payload; - struct device *dev; - struct scmi_handle *handle; -}; - -/** * struct scmi_info - Structure representing a SCMI instance * * @dev: Device pointer @@ -130,27 +96,8 @@ struct scmi_info { int users; }; -#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) -/* - * SCMI specification requires all parameters, message headers, return - * arguments or any protocol data to be expressed in little endian - * format only. - */ -struct scmi_shared_mem { - __le32 reserved; - __le32 channel_status; -#define SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR BIT(1) -#define SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE BIT(0) - __le32 reserved1[2]; - __le32 flags; -#define SCMI_SHMEM_FLAG_INTR_ENABLED BIT(0) - __le32 length; - __le32 msg_header; - u8 msg_payload[0]; -}; - static const int scmi_linux_errmap[] = { /* better than switch case as long as return value is continuous */ 0, /* SCMI_SUCCESS */ @@ -186,50 +133,6 @@ static inline void scmi_dump_header_dbg(struct device *dev, hdr->id, hdr->seq, hdr->protocol_id); } -static void scmi_fetch_response(struct scmi_xfer *xfer, - struct scmi_shared_mem __iomem *mem) -{ - xfer->hdr.status = ioread32(mem->msg_payload); - /* Skip the length of header and status in payload area i.e 8 bytes */ - xfer->rx.len = min_t(size_t, xfer->rx.len, ioread32(&mem->length) - 8); - - /* Take a copy to the rx buffer.. */ - memcpy_fromio(xfer->rx.buf, mem->msg_payload + 4, xfer->rx.len); -} - -/** - * scmi_tx_prepare() - mailbox client callback to prepare for the transfer - * - * @cl: client pointer - * @m: mailbox message - * - * This function prepares the shared memory which contains the header and the - * payload. - */ -static void scmi_tx_prepare(struct mbox_client *cl, void *m) -{ - struct scmi_xfer *t = m; - struct scmi_chan_info *cinfo = client_to_scmi_chan_info(cl); - struct scmi_shared_mem __iomem *mem = cinfo->payload; - - /* - * Ideally channel must be free by now unless OS timeout last - * request and platform continued to process the same, wait - * until it releases the shared memory, otherwise we may endup - * overwriting its response with new message payload or vice-versa - */ - spin_until_cond(ioread32(&mem->channel_status) & - SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE); - /* Mark channel busy + clear error */ - iowrite32(0x0, &mem->channel_status); - iowrite32(t->hdr.poll_completion ? 0 : SCMI_SHMEM_FLAG_INTR_ENABLED, - &mem->flags); - iowrite32(sizeof(mem->msg_header) + t->tx.len, &mem->length); - iowrite32(pack_scmi_header(&t->hdr), &mem->msg_header); - if (t->tx.buf) - memcpy_toio(mem->msg_payload, t->tx.buf, t->tx.len); -} - /** * scmi_xfer_get() - Allocate one message * @@ -298,10 +201,10 @@ __scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer) } /** - * scmi_rx_callback() - mailbox client callback for receive messages + * scmi_rx_callback() - callback for receiving messages * - * @cl: client pointer - * @m: mailbox message + * @cinfo: SCMI channel info + * @msg_hdr: Message header * * Processes one received message to appropriate transfer information and * signals completion of the transfer. @@ -309,21 +212,14 @@ __scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer) * NOTE: This function will be invoked in IRQ context, hence should be * as optimal as possible. */ -static void scmi_rx_callback(struct mbox_client *cl, void *m) +void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr) { - u8 msg_type; - u32 msg_hdr; - u16 xfer_id; - struct scmi_xfer *xfer; - struct scmi_chan_info *cinfo = client_to_scmi_chan_info(cl); - struct device *dev = cinfo->dev; struct scmi_info *info = handle_to_scmi_info(cinfo->handle); struct scmi_xfers_info *minfo = &info->tx_minfo; - struct scmi_shared_mem __iomem *mem = cinfo->payload; - - msg_hdr = ioread32(&mem->msg_header); - msg_type = MSG_XTRACT_TYPE(msg_hdr); - xfer_id = MSG_XTRACT_TOKEN(msg_hdr); + u16 xfer_id = MSG_XTRACT_TOKEN(msg_hdr); + u8 msg_type = MSG_XTRACT_TYPE(msg_hdr); + struct device *dev = cinfo->dev; + struct scmi_xfer *xfer; if (msg_type == MSG_TYPE_NOTIFICATION) return; /* Notifications not yet supported */ @@ -338,7 +234,7 @@ static void scmi_rx_callback(struct mbox_client *cl, void *m) scmi_dump_header_dbg(dev, &xfer->hdr); - scmi_fetch_response(xfer, mem); + info->desc->ops->fetch_response(cinfo, xfer); trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq, @@ -363,28 +259,15 @@ void scmi_xfer_put(const struct scmi_handle *handle, struct scmi_xfer *xfer) __scmi_xfer_put(&info->tx_minfo, xfer); } -static bool -scmi_xfer_poll_done(const struct scmi_chan_info *cinfo, struct scmi_xfer *xfer) -{ - 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 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_chan_info *cinfo, +static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer, ktime_t stop) { - ktime_t __cur = ktime_get(); + struct scmi_info *info = handle_to_scmi_info(cinfo->handle); - return scmi_xfer_poll_done(cinfo, xfer) || ktime_after(__cur, stop); + return info->desc->ops->poll_done(cinfo, xfer) || + ktime_after(ktime_get(), stop); } /** @@ -413,29 +296,26 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer) xfer->hdr.protocol_id, xfer->hdr.seq, xfer->hdr.poll_completion); - ret = mbox_send_message(cinfo->chan, xfer); + ret = info->desc->ops->send_message(cinfo, xfer); if (ret < 0) { - dev_dbg(dev, "mbox send fail %d\n", ret); + dev_dbg(dev, "Failed to send message %d\n", ret); return ret; } - /* mbox_send_message returns non-negative value on success, so reset */ - ret = 0; - 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(cinfo, xfer, stop)); if (ktime_before(ktime_get(), stop)) - scmi_fetch_response(xfer, cinfo->payload); + info->desc->ops->fetch_response(cinfo, xfer); else ret = -ETIMEDOUT; } else { /* And we wait for the response. */ timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms); if (!wait_for_completion_timeout(&xfer->done, timeout)) { - dev_err(dev, "mbox timed out in resp(caller: %pS)\n", + dev_err(dev, "timed out in resp(caller: %pS)\n", (void *)_RET_IP_); ret = -ETIMEDOUT; } @@ -444,13 +324,8 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer) if (!ret && xfer->hdr.status) ret = scmi_to_linux_errno(xfer->hdr.status); - /* - * NOTE: we might prefer not to need the mailbox ticker to manage the - * transfer queueing since the protocol layer queues things by itself. - * Unfortunately, we have to kick the mailbox framework after we have - * received our message. - */ - mbox_client_txdone(cinfo->chan, ret); + if (info->desc->ops->mark_txdone) + info->desc->ops->mark_txdone(cinfo, ret); trace_scmi_xfer_end(xfer->transfer_id, xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq, @@ -691,23 +566,12 @@ static int scmi_xfer_info_init(struct scmi_info *sinfo) return 0; } -static int scmi_mailbox_check(struct device_node *np, int idx) -{ - return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells", - idx, NULL); -} - -static int scmi_mbox_chan_setup(struct scmi_info *info, struct device *dev, - int prot_id, bool tx) +static int scmi_chan_setup(struct scmi_info *info, struct device *dev, + int prot_id, bool tx) { int ret, idx; - struct resource res; - resource_size_t size; - struct device_node *shmem, *np = dev->of_node; struct scmi_chan_info *cinfo; - struct mbox_client *cl; struct idr *idr; - const char *desc = tx ? "Tx" : "Rx"; /* Transmit channel is first entry i.e. index 0 */ idx = tx ? 0 : 1; @@ -718,7 +582,7 @@ static int scmi_mbox_chan_setup(struct scmi_info *info, struct device *dev, if (cinfo) return 0; - if (scmi_mailbox_check(np, idx)) { + if (!info->desc->ops->chan_available(dev, idx)) { cinfo = idr_find(idr, SCMI_PROTOCOL_BASE); if (unlikely(!cinfo)) /* Possible only if platform has no Rx */ return -EINVAL; @@ -731,36 +595,9 @@ static int scmi_mbox_chan_setup(struct scmi_info *info, struct device *dev, cinfo->dev = dev; - cl = &cinfo->cl; - cl->dev = dev; - cl->rx_callback = scmi_rx_callback; - cl->tx_prepare = tx ? scmi_tx_prepare : NULL; - cl->tx_block = false; - cl->knows_txdone = tx; - - shmem = of_parse_phandle(np, "shmem", idx); - ret = of_address_to_resource(shmem, 0, &res); - of_node_put(shmem); - if (ret) { - dev_err(dev, "failed to get SCMI %s payload memory\n", desc); - return ret; - } - - size = resource_size(&res); - cinfo->payload = devm_ioremap(info->dev, res.start, size); - if (!cinfo->payload) { - dev_err(dev, "failed to ioremap SCMI %s payload\n", desc); - return -EADDRNOTAVAIL; - } - - cinfo->chan = mbox_request_channel(cl, idx); - if (IS_ERR(cinfo->chan)) { - ret = PTR_ERR(cinfo->chan); - if (ret != -EPROBE_DEFER) - dev_err(dev, "failed to request SCMI %s mailbox\n", - desc); + ret = info->desc->ops->chan_setup(cinfo, info->dev, tx); + if (ret) return ret; - } idr_alloc: ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL); @@ -774,12 +611,12 @@ idr_alloc: } static inline int -scmi_mbox_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id) +scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id) { - int ret = scmi_mbox_chan_setup(info, dev, prot_id, true); + int ret = scmi_chan_setup(info, dev, prot_id, true); if (!ret) /* Rx is optional, hence no error check */ - scmi_mbox_chan_setup(info, dev, prot_id, false); + scmi_chan_setup(info, dev, prot_id, false); return ret; } @@ -797,7 +634,7 @@ scmi_create_protocol_device(struct device_node *np, struct scmi_info *info, return; } - if (scmi_mbox_txrx_setup(info, &sdev->dev, prot_id)) { + if (scmi_txrx_setup(info, &sdev->dev, prot_id)) { dev_err(&sdev->dev, "failed to setup transport\n"); scmi_device_destroy(sdev); return; @@ -850,12 +687,6 @@ static int scmi_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct device_node *child, *np = dev->of_node; - /* Only mailbox method supported, check for the presence of one */ - if (scmi_mailbox_check(np, 0)) { - dev_err(dev, "no mailbox found in %pOF\n", np); - return -EINVAL; - } - desc = of_device_get_match_data(dev); if (!desc) return -EINVAL; @@ -880,7 +711,7 @@ static int scmi_probe(struct platform_device *pdev) handle->dev = info->dev; handle->version = &info->version; - ret = scmi_mbox_txrx_setup(info, dev, SCMI_PROTOCOL_BASE); + ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE); if (ret) return ret; @@ -915,19 +746,9 @@ static int scmi_probe(struct platform_device *pdev) return 0; } -static int scmi_mbox_free_channel(int id, void *p, void *data) +void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id) { - struct scmi_chan_info *cinfo = p; - struct idr *idr = data; - - if (!IS_ERR_OR_NULL(cinfo->chan)) { - mbox_free_channel(cinfo->chan); - cinfo->chan = NULL; - } - idr_remove(idr, id); - - return 0; } static int scmi_remove(struct platform_device *pdev) @@ -947,11 +768,11 @@ static int scmi_remove(struct platform_device *pdev) return ret; /* Safe to free channels since no more users */ - ret = idr_for_each(idr, scmi_mbox_free_channel, idr); + ret = idr_for_each(idr, info->desc->ops->chan_free, idr); idr_destroy(&info->tx_idr); idr = &info->rx_idr; - ret = idr_for_each(idr, scmi_mbox_free_channel, idr); + ret = idr_for_each(idr, info->desc->ops->chan_free, idr); idr_destroy(&info->rx_idr); return ret; @@ -1003,15 +824,9 @@ static struct attribute *versions_attrs[] = { }; ATTRIBUTE_GROUPS(versions); -static const struct scmi_desc scmi_generic_desc = { - .max_rx_timeout_ms = 30, /* We may increase this if required */ - .max_msg = 20, /* Limited by MBOX_TX_QUEUE_LEN */ - .max_msg_size = 128, -}; - /* Each compatible listed below must have descriptor associated with it */ static const struct of_device_id scmi_of_match[] = { - { .compatible = "arm,scmi", .data = &scmi_generic_desc }, + { .compatible = "arm,scmi", .data = &scmi_mailbox_desc }, { /* Sentinel */ }, }; diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c new file mode 100644 index 000000000000..73077bbc4ad9 --- /dev/null +++ b/drivers/firmware/arm_scmi/mailbox.c @@ -0,0 +1,184 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * System Control and Management Interface (SCMI) Message Mailbox Transport + * driver. + * + * Copyright (C) 2019 ARM Ltd. + */ + +#include <linux/err.h> +#include <linux/device.h> +#include <linux/mailbox_client.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/slab.h> + +#include "common.h" + +/** + * struct scmi_mailbox - Structure representing a SCMI mailbox transport + * + * @cl: Mailbox Client + * @chan: Transmit/Receive mailbox channel + * @cinfo: SCMI channel info + * @shmem: Transmit/Receive shared memory area + */ +struct scmi_mailbox { + struct mbox_client cl; + struct mbox_chan *chan; + struct scmi_chan_info *cinfo; + struct scmi_shared_mem __iomem *shmem; +}; + +#define client_to_scmi_mailbox(c) container_of(c, struct scmi_mailbox, cl) + +static void tx_prepare(struct mbox_client *cl, void *m) +{ + struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl); + + shmem_tx_prepare(smbox->shmem, m); +} + +static void rx_callback(struct mbox_client *cl, void *m) +{ + struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl); + + scmi_rx_callback(smbox->cinfo, shmem_read_header(smbox->shmem)); +} + +static bool mailbox_chan_available(struct device *dev, int idx) +{ + return !of_parse_phandle_with_args(dev->of_node, "mboxes", + "#mbox-cells", idx, NULL); +} + +static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, + bool tx) +{ + const char *desc = tx ? "Tx" : "Rx"; + struct device *cdev = cinfo->dev; + struct scmi_mailbox *smbox; + struct device_node *shmem; + int ret, idx = tx ? 0 : 1; + struct mbox_client *cl; + resource_size_t size; + struct resource res; + + smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL); + if (!smbox) + return -ENOMEM; + + shmem = of_parse_phandle(cdev->of_node, "shmem", idx); + ret = of_address_to_resource(shmem, 0, &res); + of_node_put(shmem); + if (ret) { + dev_err(cdev, "failed to get SCMI %s shared memory\n", desc); + return ret; + } + + size = resource_size(&res); + smbox->shmem = devm_ioremap(dev, res.start, size); + if (!smbox->shmem) { + dev_err(dev, "failed to ioremap SCMI %s shared memory\n", desc); + return -EADDRNOTAVAIL; + } + + cl = &smbox->cl; + cl->dev = cdev; + cl->tx_prepare = tx ? tx_prepare : NULL; + cl->rx_callback = rx_callback; + cl->tx_block = false; + cl->knows_txdone = tx; + + smbox->chan = mbox_request_channel(cl, tx ? 0 : 1); + if (IS_ERR(smbox->chan)) { + ret = PTR_ERR(smbox->chan); + if (ret != -EPROBE_DEFER) + dev_err(cdev, "failed to request SCMI %s mailbox\n", + tx ? "Tx" : "Rx"); + return ret; + } + + cinfo->transport_info = smbox; + smbox->cinfo = cinfo; + + return 0; +} + +static int mailbox_chan_free(int id, void *p, void *data) +{ + struct scmi_chan_info *cinfo = p; + struct scmi_mailbox *smbox = cinfo->transport_info; + + if (!IS_ERR(smbox->chan)) { + mbox_free_channel(smbox->chan); + cinfo->transport_info = NULL; + smbox->chan = NULL; + smbox->cinfo = NULL; + } + + scmi_free_channel(cinfo, data, id); + + return 0; +} + +static int mailbox_send_message(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer) +{ + struct scmi_mailbox *smbox = cinfo->transport_info; + int ret; + + ret = mbox_send_message(smbox->chan, xfer); + + /* mbox_send_message returns non-negative value on success, so reset */ + if (ret > 0) + ret = 0; + + return ret; +} + +static void mailbox_mark_txdone(struct scmi_chan_info *cinfo, int ret) +{ + struct scmi_mailbox *smbox = cinfo->transport_info; + + /* + * NOTE: we might prefer not to need the mailbox ticker to manage the + * transfer queueing since the protocol layer queues things by itself. + * Unfortunately, we have to kick the mailbox framework after we have + * received our message. + */ + mbox_client_txdone(smbox->chan, ret); +} + +static void mailbox_fetch_response(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer) +{ + struct scmi_mailbox *smbox = cinfo->transport_info; + + shmem_fetch_response(smbox->shmem, xfer); +} + +static bool +mailbox_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer) +{ + struct scmi_mailbox *smbox = cinfo->transport_info; + + return shmem_poll_done(smbox->shmem, xfer); +} + +static struct scmi_transport_ops scmi_mailbox_ops = { + .chan_available = mailbox_chan_available, + .chan_setup = mailbox_chan_setup, + .chan_free = mailbox_chan_free, + .send_message = mailbox_send_message, + .mark_txdone = mailbox_mark_txdone, + .fetch_response = mailbox_fetch_response, + .poll_done = mailbox_poll_done, +}; + +const struct scmi_desc scmi_mailbox_desc = { + .ops = &scmi_mailbox_ops, + .max_rx_timeout_ms = 30, /* We may increase this if required */ + .max_msg = 20, /* Limited by MBOX_TX_QUEUE_LEN */ + .max_msg_size = 128, +}; diff --git a/drivers/firmware/arm_scmi/shmem.c b/drivers/firmware/arm_scmi/shmem.c new file mode 100644 index 000000000000..ca0ffd302ea2 --- /dev/null +++ b/drivers/firmware/arm_scmi/shmem.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * For transport using shared mem structure. + * + * Copyright (C) 2019 ARM Ltd. + */ + +#include <linux/io.h> +#include <linux/processor.h> +#include <linux/types.h> + +#include "common.h" + +/* + * SCMI specification requires all parameters, message headers, return + * arguments or any protocol data to be expressed in little endian + * format only. + */ +struct scmi_shared_mem { + __le32 reserved; + __le32 channel_status; +#define SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR BIT(1) +#define SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE BIT(0) + __le32 reserved1[2]; + __le32 flags; +#define SCMI_SHMEM_FLAG_INTR_ENABLED BIT(0) + __le32 length; + __le32 msg_header; + u8 msg_payload[0]; +}; + +void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem, + struct scmi_xfer *xfer) +{ + /* + * Ideally channel must be free by now unless OS timeout last + * request and platform continued to process the same, wait + * until it releases the shared memory, otherwise we may endup + * overwriting its response with new message payload or vice-versa + */ + spin_until_cond(ioread32(&shmem->channel_status) & + SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE); + /* Mark channel busy + clear error */ + iowrite32(0x0, &shmem->channel_status); + iowrite32(xfer->hdr.poll_completion ? 0 : SCMI_SHMEM_FLAG_INTR_ENABLED, + &shmem->flags); + iowrite32(sizeof(shmem->msg_header) + xfer->tx.len, &shmem->length); + iowrite32(pack_scmi_header(&xfer->hdr), &shmem->msg_header); + if (xfer->tx.buf) + memcpy_toio(shmem->msg_payload, xfer->tx.buf, xfer->tx.len); +} + +u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem) +{ + return ioread32(&shmem->msg_header); +} + +void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem, + struct scmi_xfer *xfer) +{ + xfer->hdr.status = ioread32(shmem->msg_payload); + /* Skip the length of header and status in shmem area i.e 8 bytes */ + xfer->rx.len = min_t(size_t, xfer->rx.len, + ioread32(&shmem->length) - 8); + + /* Take a copy to the rx buffer.. */ + memcpy_fromio(xfer->rx.buf, shmem->msg_payload + 4, xfer->rx.len); +} + +bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem, + struct scmi_xfer *xfer) +{ + u16 xfer_id; + + xfer_id = MSG_XTRACT_TOKEN(ioread32(&shmem->msg_header)); + + if (xfer->hdr.seq != xfer_id) + return false; + + return ioread32(&shmem->channel_status) & + (SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR | + SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE); +} |