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firmware: arm_scmi: Add xfer helpers to provide raw access

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Add a few SCMI helpers useful to implement SCMI raw access support.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20230118121426.492864-6-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
This commit is contained in:
Cristian Marussi 2023-01-18 12:14:14 +00:00 committed by Sudeep Holla
parent 37057bf2b5
commit 3095a3e25d
2 changed files with 159 additions and 0 deletions
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12
drivers/firmware/arm_scmi/common.h
View File

@ -229,6 +229,18 @@ static inline bool is_polling_enabled(struct scmi_chan_info *cinfo,
is_transport_polling_capable(desc);
}
void scmi_xfer_raw_put(const struct scmi_handle *handle,
struct scmi_xfer *xfer);
struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle);
struct scmi_chan_info *
scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id);
int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle,
struct scmi_xfer *xfer);
int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo,
struct scmi_xfer *xfer,
unsigned int timeout_ms);
#ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX
extern const struct scmi_desc scmi_mailbox_desc;
#endif

147
drivers/firmware/arm_scmi/driver.c
View File

@ -450,6 +450,53 @@ scmi_xfer_inflight_register_unlocked(struct scmi_xfer *xfer,
xfer->pending = true;
}
/**
* scmi_xfer_inflight_register - Try to register an xfer as in-flight
*
* @xfer: The xfer to register
* @minfo: Pointer to Tx/Rx Message management info based on channel type
*
* Note that this helper does NOT assume anything about the sequence number
* that was baked into the provided xfer, so it checks at first if it can
* be mapped to a free slot and fails with an error if another xfer with the
* same sequence number is currently still registered as in-flight.
*
* Return: 0 on Success or -EBUSY if sequence number embedded in the xfer
* could not rbe mapped to a free slot in the xfer_alloc_table.
*/
static int scmi_xfer_inflight_register(struct scmi_xfer *xfer,
struct scmi_xfers_info *minfo)
{
int ret = 0;
unsigned long flags;
spin_lock_irqsave(&minfo->xfer_lock, flags);
if (!test_bit(xfer->hdr.seq, minfo->xfer_alloc_table))
scmi_xfer_inflight_register_unlocked(xfer, minfo);
else
ret = -EBUSY;
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
return ret;
}
/**
* scmi_xfer_raw_inflight_register - An helper to register the given xfer as in
* flight on the TX channel, if possible.
*
* @handle: Pointer to SCMI entity handle
* @xfer: The xfer to register
*
* Return: 0 on Success, error otherwise
*/
int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle,
struct scmi_xfer *xfer)
{
struct scmi_info *info = handle_to_scmi_info(handle);
return scmi_xfer_inflight_register(xfer, &info->tx_minfo);
}
/**
* scmi_xfer_pending_set - Pick a proper sequence number and mark the xfer
* as pending in-flight
@ -525,6 +572,63 @@ static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle,
return xfer;
}
/**
* scmi_xfer_raw_get - Helper to get a bare free xfer from the TX channel
*
* @handle: Pointer to SCMI entity handle
*
* Note that xfer is taken from the TX channel structures.
*
* Return: A valid xfer on Success, or an error-pointer otherwise
*/
struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle)
{
struct scmi_xfer *xfer;
struct scmi_info *info = handle_to_scmi_info(handle);
xfer = scmi_xfer_get(handle, &info->tx_minfo);
if (!IS_ERR(xfer))
xfer->flags |= SCMI_XFER_FLAG_IS_RAW;
return xfer;
}
/**
* scmi_xfer_raw_channel_get - Helper to get a reference to the proper channel
* to use for a specific protocol_id Raw transaction.
*
* @handle: Pointer to SCMI entity handle
* @protocol_id: Identifier of the protocol
*
* Note that in a regular SCMI stack, usually, a protocol has to be defined in
* the DT to have an associated channel and be usable; but in Raw mode any
* protocol in range is allowed, re-using the Base channel, so as to enable
* fuzzing on any protocol without the need of a fully compiled DT.
*
* Return: A reference to the channel to use, or an ERR_PTR
*/
struct scmi_chan_info *
scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id)
{
struct scmi_chan_info *cinfo;
struct scmi_info *info = handle_to_scmi_info(handle);
cinfo = idr_find(&info->tx_idr, protocol_id);
if (!cinfo) {
if (protocol_id == SCMI_PROTOCOL_BASE)
return ERR_PTR(-EINVAL);
/* Use Base channel for protocols not defined for DT */
cinfo = idr_find(&info->tx_idr, SCMI_PROTOCOL_BASE);
if (!cinfo)
return ERR_PTR(-EINVAL);
dev_warn_once(handle->dev,
"Using Base channel for protocol 0x%X\n",
protocol_id);
}
return cinfo;
}
/**
* __scmi_xfer_put() - Release a message
*
@ -553,6 +657,23 @@ __scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer)
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
}
/**
* scmi_xfer_raw_put - Release an xfer that was taken by @scmi_xfer_raw_get
*
* @handle: Pointer to SCMI entity handle
* @xfer: A reference to the xfer to put
*
* Note that as with other xfer_put() handlers the xfer is really effectively
* released only if there are no more users on the system.
*/
void scmi_xfer_raw_put(const struct scmi_handle *handle, struct scmi_xfer *xfer)
{
struct scmi_info *info = handle_to_scmi_info(handle);
xfer->flags &= ~SCMI_XFER_FLAG_IS_RAW;
return __scmi_xfer_put(&info->tx_minfo, xfer);
}
/**
* scmi_xfer_lookup_unlocked - Helper to lookup an xfer_id
*
@ -979,6 +1100,32 @@ static int scmi_wait_for_message_response(struct scmi_chan_info *cinfo,
info->desc->max_rx_timeout_ms);
}
/**
* scmi_xfer_raw_wait_for_message_response - An helper to wait for a message
* reply to an xfer raw request on a specific channel for the required timeout.
*
* @cinfo: SCMI channel info
* @xfer: Reference to the transfer being waited for.
* @timeout_ms: The maximum timeout in milliseconds
*
* Return: 0 on Success, error otherwise.
*/
int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo,
struct scmi_xfer *xfer,
unsigned int timeout_ms)
{
int ret;
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
struct device *dev = info->dev;
ret = scmi_wait_for_reply(dev, info->desc, cinfo, xfer, timeout_ms);
if (ret)
dev_dbg(dev, "timed out in RAW response - HDR:%08X\n",
pack_scmi_header(&xfer->hdr));
return ret;
}
/**
* do_xfer() - Do one transfer
*