Commit cedb414a authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

Merge tag 'scmi-updates-5.7' of...

Merge tag 'scmi-updates-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into arm/drivers

ARM SCMI/SCPI updates for v5.7

1. Abstraction of the scmi transport type from the core protocol driver
   which enables addition of other transports like SMC/HVC, SPCI and
   virtio apart from the existing mailbox
2. Miscellaneous fix for minor formatting issues with the kernel-doc
   style comments
3. Replacement of zero-length array with flexible-array member which is
   part of tree-wide cleanup

* tag 'scmi-updates-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  misc: vexpress: Replace zero-length array with flexible-array member
  firmware: arm_scpi: Replace zero-length array with flexible-array member
  firmware: arm_scmi/perf: Replace zero-length array with flexible-array member
  firmware: arm_scmi: Replace zero-length array with flexible-array member
  firmware: arm_scmi: Make scmi core independent of the transport type
  firmware: arm_scmi: Move macros and helpers to common.h
  firmware: arm_scmi: Update doc style comments

Link: https://lore.kernel.org/r/20200304175247.GA5402@bogus


Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parents 021249ec 57c45d4d
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+2 −1
Original line number Diff line number Diff line
# 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
+113 −2
Original line number Diff line number Diff line
@@ -33,8 +33,8 @@ enum scmi_common_cmd {
/**
 * struct scmi_msg_resp_prot_version - Response for a message
 *
 * @major_version: Major version of the ABI that firmware supports
 * @minor_version: Minor version of the ABI that firmware supports
 * @major_version: Major version of the ABI that firmware supports
 *
 * In general, ABI version changes follow the rule that minor version increments
 * are backward compatible. Major revision changes in ABI may not be
@@ -47,6 +47,19 @@ struct scmi_msg_resp_prot_version {
	__le16 major_version;
};

#define MSG_ID_MASK		GENMASK(7, 0)
#define MSG_XTRACT_ID(hdr)	FIELD_GET(MSG_ID_MASK, (hdr))
#define MSG_TYPE_MASK		GENMASK(9, 8)
#define MSG_XTRACT_TYPE(hdr)	FIELD_GET(MSG_TYPE_MASK, (hdr))
#define MSG_TYPE_COMMAND	0
#define MSG_TYPE_DELAYED_RESP	2
#define MSG_TYPE_NOTIFICATION	3
#define MSG_PROTOCOL_ID_MASK	GENMASK(17, 10)
#define MSG_XTRACT_PROT_ID(hdr)	FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr))
#define MSG_TOKEN_ID_MASK	GENMASK(27, 18)
#define MSG_XTRACT_TOKEN(hdr)	FIELD_GET(MSG_TOKEN_ID_MASK, (hdr))
#define MSG_TOKEN_MAX		(MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1)

/**
 * struct scmi_msg_hdr - Message(Tx/Rx) header
 *
@@ -67,6 +80,33 @@ struct scmi_msg_hdr {
	bool poll_completion;
};

/**
 * pack_scmi_header() - packs and returns 32-bit header
 *
 * @hdr: pointer to header containing all the information on message id,
 *	protocol id and sequence id.
 *
 * Return: 32-bit packed message header to be sent to the platform.
 */
static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
{
	return FIELD_PREP(MSG_ID_MASK, hdr->id) |
		FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) |
		FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id);
}

/**
 * unpack_scmi_header() - unpacks and records message and protocol id
 *
 * @msg_hdr: 32-bit packed message header sent from the platform
 * @hdr: pointer to header to fetch message and protocol id.
 */
static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)
{
	hdr->id = MSG_XTRACT_ID(msg_hdr);
	hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr);
}

/**
 * struct scmi_msg - Message(Tx/Rx) structure
 *
@@ -88,7 +128,7 @@ struct scmi_msg {
 *	message. If request-ACK protocol is used, we can reuse the same
 *	buffer for the rx path as we use for the tx path.
 * @done: command message transmit completion event
 * @async: pointer to delayed response message received event completion
 * @async_done: pointer to delayed response message received event completion
 */
struct scmi_xfer {
	int transfer_id;
@@ -113,3 +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);
+34 −259
Original line number Diff line number Diff line
@@ -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"
@@ -32,19 +30,6 @@
#define CREATE_TRACE_POINTS
#include <trace/events/scmi.h>

#define MSG_ID_MASK		GENMASK(7, 0)
#define MSG_XTRACT_ID(hdr)	FIELD_GET(MSG_ID_MASK, (hdr))
#define MSG_TYPE_MASK		GENMASK(9, 8)
#define MSG_XTRACT_TYPE(hdr)	FIELD_GET(MSG_TYPE_MASK, (hdr))
#define MSG_TYPE_COMMAND	0
#define MSG_TYPE_DELAYED_RESP	2
#define MSG_TYPE_NOTIFICATION	3
#define MSG_PROTOCOL_ID_MASK	GENMASK(17, 10)
#define MSG_XTRACT_PROT_ID(hdr)	FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr))
#define MSG_TOKEN_ID_MASK	GENMASK(27, 18)
#define MSG_XTRACT_TOKEN(hdr)	FIELD_GET(MSG_TOKEN_ID_MASK, (hdr))
#define MSG_TOKEN_MAX		(MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1)

enum scmi_error_codes {
	SCMI_SUCCESS = 0,	/* Success */
	SCMI_ERR_SUPPORT = -1,	/* Not supported */
@@ -82,46 +67,14 @@ struct scmi_xfers_info {
	spinlock_t xfer_lock;
};

/**
 * 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
 * @desc: SoC description for this instance
 * @handle: Instance of SCMI handle to send to clients
 * @version: SCMI revision information containing protocol version,
 *	implementation version and (sub-)vendor identification.
 * @handle: Instance of SCMI handle to send to clients
 * @tx_minfo: Universal Transmit Message management info
 * @tx_idr: IDR object to map protocol id to Tx channel info pointer
 * @rx_idr: IDR object to map protocol id to Rx channel info pointer
@@ -143,27 +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 */
@@ -199,77 +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);
}

/**
 * pack_scmi_header() - packs and returns 32-bit header
 *
 * @hdr: pointer to header containing all the information on message id,
 *	protocol id and sequence id.
 *
 * Return: 32-bit packed message header to be sent to the platform.
 */
static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
{
	return FIELD_PREP(MSG_ID_MASK, hdr->id) |
		FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) |
		FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id);
}

/**
 * unpack_scmi_header() - unpacks and records message and protocol id
 *
 * @msg_hdr: 32-bit packed message header sent from the platform
 * @hdr: pointer to header to fetch message and protocol id.
 */
static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)
{
	hdr->id = MSG_XTRACT_ID(msg_hdr);
	hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr);
}

/**
 * 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
 *
@@ -338,10 +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.
@@ -349,21 +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 */
@@ -378,7 +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,
@@ -403,28 +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);
}

/**
@@ -453,29 +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;
		}
@@ -484,13 +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,
@@ -731,23 +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,
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;
@@ -758,7 +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;
@@ -771,36 +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);
@@ -814,12 +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;
}
@@ -837,7 +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;
@@ -890,12 +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;
@@ -920,7 +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;

@@ -955,19 +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)
@@ -987,11 +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;
@@ -1043,15 +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 */ },
};

+184 −0
Original line number Diff line number Diff line
// 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,
};
+1 −1
Original line number Diff line number Diff line
@@ -89,7 +89,7 @@ struct scmi_msg_resp_perf_describe_levels {
		__le32 power;
		__le16 transition_latency_us;
		__le16 reserved;
	} opp[0];
	} opp[];
};

struct scmi_perf_get_fc_info {
Loading