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path: root/drivers/firmware/arm_scmi/driver.c
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Diffstat (limited to 'drivers/firmware/arm_scmi/driver.c')
-rw-r--r--drivers/firmware/arm_scmi/driver.c366
1 files changed, 233 insertions, 133 deletions
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index b5bc4c7a8fab..3eb0382491ce 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -30,8 +30,14 @@
#include "common.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)
@@ -86,7 +92,7 @@ struct scmi_desc {
};
/**
- * struct scmi_chan_info - Structure representing a SCMI channel informfation
+ * struct scmi_chan_info - Structure representing a SCMI channel information
*
* @cl: Mailbox Client
* @chan: Transmit/Receive mailbox channel
@@ -111,8 +117,9 @@ struct scmi_chan_info {
* @handle: Instance of SCMI handle to send to clients
* @version: SCMI revision information containing protocol version,
* implementation version and (sub-)vendor identification.
- * @minfo: Message info
- * @tx_idr: IDR object to map protocol id to channel info pointer
+ * @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
* @protocols_imp: List of protocols implemented, currently maximum of
* MAX_PROTOCOLS_IMP elements allocated by the base protocol
* @node: List head
@@ -123,8 +130,9 @@ struct scmi_info {
const struct scmi_desc *desc;
struct scmi_revision_info version;
struct scmi_handle handle;
- struct scmi_xfers_info minfo;
+ struct scmi_xfers_info tx_minfo;
struct idr tx_idr;
+ struct idr rx_idr;
u8 *protocols_imp;
struct list_head node;
int users;
@@ -182,7 +190,7 @@ static inline int scmi_to_linux_errno(int errno)
static inline void scmi_dump_header_dbg(struct device *dev,
struct scmi_msg_hdr *hdr)
{
- dev_dbg(dev, "Command ID: %x Sequence ID: %x Protocol: %x\n",
+ dev_dbg(dev, "Message ID: %x Sequence ID: %x Protocol: %x\n",
hdr->id, hdr->seq, hdr->protocol_id);
}
@@ -190,7 +198,7 @@ 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 statues in payload area i.e 8 bytes*/
+ /* 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.. */
@@ -198,56 +206,12 @@ static void scmi_fetch_response(struct scmi_xfer *xfer,
}
/**
- * scmi_rx_callback() - mailbox client callback for receive messages
- *
- * @cl: client pointer
- * @m: mailbox message
- *
- * Processes one received message to appropriate transfer information and
- * signals completion of the transfer.
- *
- * 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)
-{
- 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->minfo;
- struct scmi_shared_mem __iomem *mem = cinfo->payload;
-
- xfer_id = MSG_XTRACT_TOKEN(ioread32(&mem->msg_header));
-
- /* Are we even expecting this? */
- if (!test_bit(xfer_id, minfo->xfer_alloc_table)) {
- dev_err(dev, "message for %d is not expected!\n", xfer_id);
- return;
- }
-
- xfer = &minfo->xfer_block[xfer_id];
-
- scmi_dump_header_dbg(dev, &xfer->hdr);
- /* Is the message of valid length? */
- if (xfer->rx.len > info->desc->max_msg_size) {
- dev_err(dev, "unable to handle %zu xfer(max %d)\n",
- xfer->rx.len, info->desc->max_msg_size);
- return;
- }
-
- scmi_fetch_response(xfer, mem);
- complete(&xfer->done);
-}
-
-/**
* 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 command header to be sent to the platform.
+ * Return: 32-bit packed message header to be sent to the platform.
*/
static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
{
@@ -257,6 +221,18 @@ static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
}
/**
+ * 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
@@ -271,6 +247,14 @@ static void scmi_tx_prepare(struct mbox_client *cl, void *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,
@@ -285,8 +269,9 @@ static void scmi_tx_prepare(struct mbox_client *cl, void *m)
* scmi_xfer_get() - Allocate one message
*
* @handle: Pointer to SCMI entity handle
+ * @minfo: Pointer to Tx/Rx Message management info based on channel type
*
- * Helper function which is used by various command functions that are
+ * Helper function which is used by various message functions that are
* exposed to clients of this driver for allocating a message traffic event.
*
* This function can sleep depending on pending requests already in the system
@@ -295,13 +280,13 @@ static void scmi_tx_prepare(struct mbox_client *cl, void *m)
*
* Return: 0 if all went fine, else corresponding error.
*/
-static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle)
+static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle,
+ struct scmi_xfers_info *minfo)
{
u16 xfer_id;
struct scmi_xfer *xfer;
unsigned long flags, bit_pos;
struct scmi_info *info = handle_to_scmi_info(handle);
- struct scmi_xfers_info *minfo = &info->minfo;
/* Keep the locked section as small as possible */
spin_lock_irqsave(&minfo->xfer_lock, flags);
@@ -324,18 +309,17 @@ static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle)
}
/**
- * scmi_xfer_put() - Release a message
+ * __scmi_xfer_put() - Release a message
*
- * @handle: Pointer to SCMI entity handle
+ * @minfo: Pointer to Tx/Rx Message management info based on channel type
* @xfer: message that was reserved by scmi_xfer_get
*
* This holds a spinlock to maintain integrity of internal data structures.
*/
-void scmi_xfer_put(const struct scmi_handle *handle, struct scmi_xfer *xfer)
+static void
+__scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer)
{
unsigned long flags;
- struct scmi_info *info = handle_to_scmi_info(handle);
- struct scmi_xfers_info *minfo = &info->minfo;
/*
* Keep the locked section as small as possible
@@ -347,6 +331,68 @@ void scmi_xfer_put(const struct scmi_handle *handle, struct scmi_xfer *xfer)
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
}
+/**
+ * scmi_rx_callback() - mailbox client callback for receive messages
+ *
+ * @cl: client pointer
+ * @m: mailbox message
+ *
+ * Processes one received message to appropriate transfer information and
+ * signals completion of the transfer.
+ *
+ * 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)
+{
+ 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);
+
+ if (msg_type == MSG_TYPE_NOTIFICATION)
+ return; /* Notifications not yet supported */
+
+ /* Are we even expecting this? */
+ if (!test_bit(xfer_id, minfo->xfer_alloc_table)) {
+ dev_err(dev, "message for %d is not expected!\n", xfer_id);
+ return;
+ }
+
+ xfer = &minfo->xfer_block[xfer_id];
+
+ scmi_dump_header_dbg(dev, &xfer->hdr);
+
+ scmi_fetch_response(xfer, mem);
+
+ if (msg_type == MSG_TYPE_DELAYED_RESP)
+ complete(xfer->async_done);
+ else
+ complete(&xfer->done);
+}
+
+/**
+ * scmi_xfer_put() - Release a transmit message
+ *
+ * @handle: Pointer to SCMI entity handle
+ * @xfer: message that was reserved by scmi_xfer_get
+ */
+void scmi_xfer_put(const struct scmi_handle *handle, struct scmi_xfer *xfer)
+{
+ struct scmi_info *info = handle_to_scmi_info(handle);
+
+ __scmi_xfer_put(&info->tx_minfo, xfer);
+}
+
static bool
scmi_xfer_poll_done(const struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
{
@@ -435,8 +481,36 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
return ret;
}
+#define SCMI_MAX_RESPONSE_TIMEOUT (2 * MSEC_PER_SEC)
+
+/**
+ * scmi_do_xfer_with_response() - Do one transfer and wait until the delayed
+ * response is received
+ *
+ * @handle: Pointer to SCMI entity handle
+ * @xfer: Transfer to initiate and wait for response
+ *
+ * Return: -ETIMEDOUT in case of no delayed response, if transmit error,
+ * return corresponding error, else if all goes well, return 0.
+ */
+int scmi_do_xfer_with_response(const struct scmi_handle *handle,
+ struct scmi_xfer *xfer)
+{
+ int ret, timeout = msecs_to_jiffies(SCMI_MAX_RESPONSE_TIMEOUT);
+ DECLARE_COMPLETION_ONSTACK(async_response);
+
+ xfer->async_done = &async_response;
+
+ ret = scmi_do_xfer(handle, xfer);
+ if (!ret && !wait_for_completion_timeout(xfer->async_done, timeout))
+ ret = -ETIMEDOUT;
+
+ xfer->async_done = NULL;
+ return ret;
+}
+
/**
- * scmi_xfer_get_init() - Allocate and initialise one message
+ * scmi_xfer_get_init() - Allocate and initialise one message for transmit
*
* @handle: Pointer to SCMI entity handle
* @msg_id: Message identifier
@@ -457,6 +531,7 @@ int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id,
int ret;
struct scmi_xfer *xfer;
struct scmi_info *info = handle_to_scmi_info(handle);
+ struct scmi_xfers_info *minfo = &info->tx_minfo;
struct device *dev = info->dev;
/* Ensure we have sane transfer sizes */
@@ -464,7 +539,7 @@ int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id,
tx_size > info->desc->max_msg_size)
return -ERANGE;
- xfer = scmi_xfer_get(handle);
+ xfer = scmi_xfer_get(handle, minfo);
if (IS_ERR(xfer)) {
ret = PTR_ERR(xfer);
dev_err(dev, "failed to get free message slot(%d)\n", ret);
@@ -597,27 +672,13 @@ int scmi_handle_put(const struct scmi_handle *handle)
return 0;
}
-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 },
- { /* Sentinel */ },
-};
-
-MODULE_DEVICE_TABLE(of, scmi_of_match);
-
static int scmi_xfer_info_init(struct scmi_info *sinfo)
{
int i;
struct scmi_xfer *xfer;
struct device *dev = sinfo->dev;
const struct scmi_desc *desc = sinfo->desc;
- struct scmi_xfers_info *info = &sinfo->minfo;
+ struct scmi_xfers_info *info = &sinfo->tx_minfo;
/* Pre-allocated messages, no more than what hdr.seq can support */
if (WARN_ON(desc->max_msg >= MSG_TOKEN_MAX)) {
@@ -652,61 +713,32 @@ static int scmi_xfer_info_init(struct scmi_info *sinfo)
return 0;
}
-static int scmi_mailbox_check(struct device_node *np)
+static int scmi_mailbox_check(struct device_node *np, int idx)
{
- return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells", 0, NULL);
+ return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells",
+ idx, NULL);
}
-static int scmi_mbox_free_channel(int id, void *p, void *data)
+static int scmi_mbox_chan_setup(struct scmi_info *info, struct device *dev,
+ int prot_id, bool tx)
{
- 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)
-{
- int ret = 0;
- struct scmi_info *info = platform_get_drvdata(pdev);
- struct idr *idr = &info->tx_idr;
-
- mutex_lock(&scmi_list_mutex);
- if (info->users)
- ret = -EBUSY;
- else
- list_del(&info->node);
- mutex_unlock(&scmi_list_mutex);
-
- if (ret)
- return ret;
-
- /* Safe to free channels since no more users */
- ret = idr_for_each(idr, scmi_mbox_free_channel, idr);
- idr_destroy(&info->tx_idr);
-
- return ret;
-}
-
-static inline int
-scmi_mbox_chan_setup(struct scmi_info *info, struct device *dev, int prot_id)
-{
- int ret;
+ 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";
- if (scmi_mailbox_check(np)) {
- cinfo = idr_find(&info->tx_idr, SCMI_PROTOCOL_BASE);
+ /* Transmit channel is first entry i.e. index 0 */
+ idx = tx ? 0 : 1;
+ idr = tx ? &info->tx_idr : &info->rx_idr;
+
+ if (scmi_mailbox_check(np, idx)) {
+ cinfo = idr_find(idr, SCMI_PROTOCOL_BASE);
+ if (unlikely(!cinfo)) /* Possible only if platform has no Rx */
+ return -EINVAL;
goto idr_alloc;
}
@@ -719,36 +751,36 @@ scmi_mbox_chan_setup(struct scmi_info *info, struct device *dev, int prot_id)
cl = &cinfo->cl;
cl->dev = dev;
cl->rx_callback = scmi_rx_callback;
- cl->tx_prepare = scmi_tx_prepare;
+ cl->tx_prepare = tx ? scmi_tx_prepare : NULL;
cl->tx_block = false;
- cl->knows_txdone = true;
+ cl->knows_txdone = tx;
- shmem = of_parse_phandle(np, "shmem", 0);
+ 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 Tx payload mem resource\n");
+ 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 Tx payload\n");
+ dev_err(dev, "failed to ioremap SCMI %s payload\n", desc);
return -EADDRNOTAVAIL;
}
- /* Transmit channel is first entry i.e. index 0 */
- cinfo->chan = mbox_request_channel(cl, 0);
+ 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 Tx mailbox\n");
+ dev_err(dev, "failed to request SCMI %s mailbox\n",
+ desc);
return ret;
}
idr_alloc:
- ret = idr_alloc(&info->tx_idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL);
+ ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL);
if (ret != prot_id) {
dev_err(dev, "unable to allocate SCMI idr slot err %d\n", ret);
return ret;
@@ -758,6 +790,17 @@ idr_alloc:
return 0;
}
+static inline int
+scmi_mbox_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id)
+{
+ int ret = scmi_mbox_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);
+
+ return ret;
+}
+
static inline void
scmi_create_protocol_device(struct device_node *np, struct scmi_info *info,
int prot_id)
@@ -771,7 +814,7 @@ scmi_create_protocol_device(struct device_node *np, struct scmi_info *info,
return;
}
- if (scmi_mbox_chan_setup(info, &sdev->dev, prot_id)) {
+ if (scmi_mbox_txrx_setup(info, &sdev->dev, prot_id)) {
dev_err(&sdev->dev, "failed to setup transport\n");
scmi_device_destroy(sdev);
return;
@@ -791,7 +834,7 @@ static int scmi_probe(struct platform_device *pdev)
struct device_node *child, *np = dev->of_node;
/* Only mailbox method supported, check for the presence of one */
- if (scmi_mailbox_check(np)) {
+ if (scmi_mailbox_check(np, 0)) {
dev_err(dev, "no mailbox found in %pOF\n", np);
return -EINVAL;
}
@@ -814,12 +857,13 @@ static int scmi_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, info);
idr_init(&info->tx_idr);
+ idr_init(&info->rx_idr);
handle = &info->handle;
handle->dev = info->dev;
handle->version = &info->version;
- ret = scmi_mbox_chan_setup(info, dev, SCMI_PROTOCOL_BASE);
+ ret = scmi_mbox_txrx_setup(info, dev, SCMI_PROTOCOL_BASE);
if (ret)
return ret;
@@ -854,6 +898,62 @@ static int scmi_probe(struct platform_device *pdev)
return 0;
}
+static int scmi_mbox_free_channel(int id, void *p, void *data)
+{
+ 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)
+{
+ int ret = 0;
+ struct scmi_info *info = platform_get_drvdata(pdev);
+ struct idr *idr = &info->tx_idr;
+
+ mutex_lock(&scmi_list_mutex);
+ if (info->users)
+ ret = -EBUSY;
+ else
+ list_del(&info->node);
+ mutex_unlock(&scmi_list_mutex);
+
+ if (ret)
+ return ret;
+
+ /* Safe to free channels since no more users */
+ ret = idr_for_each(idr, scmi_mbox_free_channel, idr);
+ idr_destroy(&info->tx_idr);
+
+ idr = &info->rx_idr;
+ ret = idr_for_each(idr, scmi_mbox_free_channel, idr);
+ idr_destroy(&info->rx_idr);
+
+ return ret;
+}
+
+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 },
+ { /* Sentinel */ },
+};
+
+MODULE_DEVICE_TABLE(of, scmi_of_match);
+
static struct platform_driver scmi_driver = {
.driver = {
.name = "arm-scmi",