scsi: mpt3sas: Add support for MCTP Passthrough commands

JIRA: https://issues.redhat.com/browse/RHEL-81907

The MPI specification defines support for sending MCTP management commands
as a passthrough function to the IOC. Add support for driver to discover
the IOC capability to support MCTP passthrough function. Driver will
support applications and kernel modules to send MPT commands containing the
MCTP passthrough request to firmware through an MPI request.

Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Signed-off-by: Sathya Prakash <sathya.prakash@broadcom.com>
Link: https://lore.kernel.org/r/1739410016-27503-3-git-send-email-shivasharan.srikanteshwara@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit c72be4b)
Signed-off-by: Chandrakanth Patil <chanpati@redhat.com>

Author: Chandrakanth Patil

drivers/scsi/mpt3sas/mpt3sas_base.c

@@ -1202,6 +1202,11 @@ _base_sas_ioc_info(struct MPT3SAS_ADAPTER *ioc, MPI2DefaultReply_t *mpi_reply,
 		    ioc->sge_size;
 		func_str = "nvme_encapsulated";
 		break;
+	case MPI2_FUNCTION_MCTP_PASSTHROUGH:
+		frame_sz = sizeof(Mpi26MctpPassthroughRequest_t) +
+		    ioc->sge_size;
+		func_str = "mctp_passthru";
+		break;
 	default:
 		frame_sz = 32;
 		func_str = "unknown";
@@ -4874,6 +4879,12 @@ _base_display_ioc_capabilities(struct MPT3SAS_ADAPTER *ioc)
 		i++;
 	}
 
+	if (ioc->facts.IOCCapabilities &
+	    MPI26_IOCFACTS_CAPABILITY_MCTP_PASSTHRU) {
+		pr_cont("%sMCTP Passthru", i ? "," : "");
+		i++;
+	}
+
 	iounit_pg1_flags = le32_to_cpu(ioc->iounit_pg1.Flags);
 	if (!(iounit_pg1_flags & MPI2_IOUNITPAGE1_NATIVE_COMMAND_Q_DISABLE)) {
 		pr_cont("%sNCQ", i ? "," : "");

drivers/scsi/mpt3sas/mpt3sas_ctl.c

@@ -186,6 +186,9 @@ _ctl_display_some_debug(struct MPT3SAS_ADAPTER *ioc, u16 smid,
 	case MPI2_FUNCTION_NVME_ENCAPSULATED:
 		desc = "nvme_encapsulated";
 		break;
+	case MPI2_FUNCTION_MCTP_PASSTHROUGH:
+		desc = "mctp_passthrough";
+		break;
 	}
 
 	if (!desc)
@@ -652,6 +655,40 @@ _ctl_set_task_mid(struct MPT3SAS_ADAPTER *ioc, struct mpt3_ioctl_command *karg,
 	return 0;
 }
 
+/**
+ * _ctl_send_mctp_passthru_req - Send an MCTP passthru request
+ * @ioc: per adapter object
+ * @mctp_passthru_req: MPI mctp passhthru request from caller
+ * @psge: pointer to the H2DSGL
+ * @data_out_dma: DMA buffer for H2D SGL
+ * @data_out_sz: H2D length
+ * @data_in_dma: DMA buffer for D2H SGL
+ * @data_in_sz: D2H length
+ * @smid: SMID to submit the request
+ *
+ */
+static void
+_ctl_send_mctp_passthru_req(
+	struct MPT3SAS_ADAPTER *ioc,
+	Mpi26MctpPassthroughRequest_t *mctp_passthru_req, void *psge,
+	dma_addr_t data_out_dma, int data_out_sz,
+	dma_addr_t data_in_dma, int data_in_sz,
+	u16 smid)
+{
+	mctp_passthru_req->H2DLength = data_out_sz;
+	mctp_passthru_req->D2HLength = data_in_sz;
+
+	/* Build the H2D SGL from the data out buffer */
+	ioc->build_sg(ioc, psge, data_out_dma, data_out_sz, 0, 0);
+
+	psge += ioc->sge_size_ieee;
+
+	/* Build the D2H SGL for the data in buffer */
+	ioc->build_sg(ioc, psge, 0, 0, data_in_dma, data_in_sz);
+
+	ioc->put_smid_default(ioc, smid);
+}
+
 /**
  * _ctl_do_mpt_command - main handler for MPT3COMMAND opcode
  * @ioc: per adapter object
@@ -792,6 +829,23 @@ _ctl_do_mpt_command(struct MPT3SAS_ADAPTER *ioc, struct mpt3_ioctl_command karg,
 
 	init_completion(&ioc->ctl_cmds.done);
 	switch (mpi_request->Function) {
+	case MPI2_FUNCTION_MCTP_PASSTHROUGH:
+	{
+		Mpi26MctpPassthroughRequest_t *mctp_passthru_req =
+						(Mpi26MctpPassthroughRequest_t *)request;
+
+		if (!(ioc->facts.IOCCapabilities & MPI26_IOCFACTS_CAPABILITY_MCTP_PASSTHRU)) {
+			ioc_err(ioc, "%s: MCTP Passthrough request not supported\n",
+				__func__);
+			mpt3sas_base_free_smid(ioc, smid);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		_ctl_send_mctp_passthru_req(ioc, mctp_passthru_req, psge, data_out_dma,
+					data_out_sz, data_in_dma, data_in_sz, smid);
+		break;
+	}
 	case MPI2_FUNCTION_NVME_ENCAPSULATED:
 	{
 		nvme_encap_request = (Mpi26NVMeEncapsulatedRequest_t *)request;
@@ -2786,6 +2840,217 @@ _ctl_ioctl_main(struct file *file, unsigned int cmd, void __user *arg,
 	return ret;
 }
 
+/**
+ * _ctl_get_mpt_mctp_passthru_adapter - Traverse the IOC list and return the IOC at
+ *					dev_index positionthat support MCTP passhtru
+ * @dev_index: position in the mpt3sas_ioc_list to search for
+ * Return pointer to the IOC on success
+ *	  NULL if device not found error
+ */
+static struct MPT3SAS_ADAPTER *
+_ctl_get_mpt_mctp_passthru_adapter(int dev_index)
+{
+	struct MPT3SAS_ADAPTER *ioc = NULL;
+	int count = 0;
+
+	spin_lock(&gioc_lock);
+	/* Traverse ioc list and return number of IOC that support MCTP passthru */
+	list_for_each_entry(ioc, &mpt3sas_ioc_list, list) {
+		if (ioc->facts.IOCCapabilities & MPI26_IOCFACTS_CAPABILITY_MCTP_PASSTHRU) {
+			if (count == dev_index) {
+				spin_unlock(&gioc_lock);
+				return 0;
+			}
+		}
+	}
+	spin_unlock(&gioc_lock);
+
+	return NULL;
+}
+
+/**
+ * mpt3sas_get_device_count - Retrieve the count of MCTP passthrough
+ *				capable devices managed by the driver.
+ *
+ * Returns number of devices that support MCTP passthrough.
+ */
+int
+mpt3sas_get_device_count(void)
+{
+	int count = 0;
+	struct MPT3SAS_ADAPTER *ioc = NULL;
+
+	spin_lock(&gioc_lock);
+	/* Traverse ioc list and return number of IOC that support MCTP passthru */
+	list_for_each_entry(ioc, &mpt3sas_ioc_list, list)
+		if (ioc->facts.IOCCapabilities & MPI26_IOCFACTS_CAPABILITY_MCTP_PASSTHRU)
+			count++;
+
+	spin_unlock(&gioc_lock);
+
+	return count;
+}
+EXPORT_SYMBOL(mpt3sas_get_device_count);
+
+/**
+ * mpt3sas_send_passthru_cmd - Send an MPI MCTP passthrough command to
+ *				firmware
+ * @command: The MPI MCTP passthrough command to send to firmware
+ *
+ * Returns 0 on success, anything else is error.
+ */
+int mpt3sas_send_mctp_passthru_req(struct mpt3_passthru_command *command)
+{
+	struct MPT3SAS_ADAPTER *ioc;
+	MPI2RequestHeader_t *mpi_request = NULL, *request;
+	MPI2DefaultReply_t *mpi_reply;
+	Mpi26MctpPassthroughRequest_t *mctp_passthru_req;
+	u16 smid;
+	unsigned long timeout;
+	u8 issue_reset = 0;
+	u32 sz;
+	void *psge;
+	void *data_out = NULL;
+	dma_addr_t data_out_dma = 0;
+	size_t data_out_sz = 0;
+	void *data_in = NULL;
+	dma_addr_t data_in_dma = 0;
+	size_t data_in_sz = 0;
+	long ret;
+
+	/* Retrieve ioc from dev_index */
+	ioc = _ctl_get_mpt_mctp_passthru_adapter(command->dev_index);
+	if (!ioc)
+		return -ENODEV;
+
+	mutex_lock(&ioc->pci_access_mutex);
+	if (ioc->shost_recovery ||
+	    ioc->pci_error_recovery || ioc->is_driver_loading ||
+	    ioc->remove_host) {
+		ret = -EAGAIN;
+		goto unlock_pci_access;
+	}
+
+	/* Lock the ctl_cmds mutex to ensure a single ctl cmd is pending */
+	if (mutex_lock_interruptible(&ioc->ctl_cmds.mutex)) {
+		ret = -ERESTARTSYS;
+		goto unlock_pci_access;
+	}
+
+	if (ioc->ctl_cmds.status != MPT3_CMD_NOT_USED) {
+		ioc_err(ioc, "%s: ctl_cmd in use\n", __func__);
+		ret = -EAGAIN;
+		goto unlock_ctl_cmds;
+	}
+
+	ret = mpt3sas_wait_for_ioc(ioc,	IOC_OPERATIONAL_WAIT_COUNT);
+	if (ret)
+		goto unlock_ctl_cmds;
+
+	mpi_request = (MPI2RequestHeader_t *)command->mpi_request;
+	if (mpi_request->Function != MPI2_FUNCTION_MCTP_PASSTHROUGH) {
+		ioc_err(ioc, "%s: Invalid request receveid, Function 0x%x\n",
+			__func__, mpi_request->Function);
+		ret = -EINVAL;
+		goto unlock_ctl_cmds;
+	}
+
+	/* Use first reserved smid for passthrough commands */
+	smid = ioc->scsiio_depth - INTERNAL_SCSIIO_CMDS_COUNT + 1;
+	ret = 0;
+	ioc->ctl_cmds.status = MPT3_CMD_PENDING;
+	memset(ioc->ctl_cmds.reply, 0, ioc->reply_sz);
+	request = mpt3sas_base_get_msg_frame(ioc, smid);
+	memset(request, 0, ioc->request_sz);
+	memcpy(request, command->mpi_request, sizeof(Mpi26MctpPassthroughRequest_t));
+	ioc->ctl_cmds.smid = smid;
+	data_out_sz = command->data_out_size;
+	data_in_sz = command->data_in_size;
+
+	/* obtain dma-able memory for data transfer */
+	if (data_out_sz) /* WRITE */ {
+		data_out = dma_alloc_coherent(&ioc->pdev->dev, data_out_sz,
+					      &data_out_dma, GFP_ATOMIC);
+		if (!data_out) {
+			ret = -ENOMEM;
+			mpt3sas_base_free_smid(ioc, smid);
+			goto out;
+		}
+		memcpy(data_out, command->data_out_buf_ptr, data_out_sz);
+
+	}
+
+	if (data_in_sz) /* READ */ {
+		data_in = dma_alloc_coherent(&ioc->pdev->dev, data_in_sz,
+					     &data_in_dma, GFP_ATOMIC);
+		if (!data_in) {
+			ret = -ENOMEM;
+			mpt3sas_base_free_smid(ioc, smid);
+			goto out;
+		}
+	}
+
+	psge = &((Mpi26MctpPassthroughRequest_t *)request)->H2DSGL;
+
+	init_completion(&ioc->ctl_cmds.done);
+
+	mctp_passthru_req = (Mpi26MctpPassthroughRequest_t *)request;
+
+	_ctl_send_mctp_passthru_req(ioc, mctp_passthru_req, psge, data_out_dma,
+				data_out_sz, data_in_dma, data_in_sz, smid);
+
+	timeout = command->timeout;
+	if (timeout < MPT3_IOCTL_DEFAULT_TIMEOUT)
+		timeout = MPT3_IOCTL_DEFAULT_TIMEOUT;
+
+	wait_for_completion_timeout(&ioc->ctl_cmds.done, timeout*HZ);
+	if (!(ioc->ctl_cmds.status & MPT3_CMD_COMPLETE)) {
+		mpt3sas_check_cmd_timeout(ioc,
+		    ioc->ctl_cmds.status, mpi_request,
+		    sizeof(Mpi26MctpPassthroughRequest_t), issue_reset);
+		goto issue_host_reset;
+	}
+
+	mpi_reply = ioc->ctl_cmds.reply;
+
+	/* copy out xdata to user */
+	if (data_in_sz)
+		memcpy(command->data_in_buf_ptr, data_in, data_in_sz);
+
+	/* copy out reply message frame to user */
+	if (command->max_reply_bytes) {
+		sz = min_t(u32, command->max_reply_bytes, ioc->reply_sz);
+		memcpy(command->reply_frame_buf_ptr, ioc->ctl_cmds.reply, sz);
+	}
+
+issue_host_reset:
+	if (issue_reset) {
+		ret = -ENODATA;
+		mpt3sas_base_hard_reset_handler(ioc, FORCE_BIG_HAMMER);
+	}
+
+out:
+	/* free memory associated with sg buffers */
+	if (data_in)
+		dma_free_coherent(&ioc->pdev->dev, data_in_sz, data_in,
+		    data_in_dma);
+
+	if (data_out)
+		dma_free_coherent(&ioc->pdev->dev, data_out_sz, data_out,
+		    data_out_dma);
+
+	ioc->ctl_cmds.status = MPT3_CMD_NOT_USED;
+
+unlock_ctl_cmds:
+	mutex_unlock(&ioc->ctl_cmds.mutex);
+
+unlock_pci_access:
+	mutex_unlock(&ioc->pci_access_mutex);
+	return ret;
+
+}
+EXPORT_SYMBOL(mpt3sas_send_mctp_passthru_req);
+
 /**
  * _ctl_ioctl - mpt3ctl main ioctl entry point (unlocked)
  * @file: (struct file)

drivers/scsi/mpt3sas/mpt3sas_ctl.h

@@ -458,4 +458,46 @@ struct mpt3_enable_diag_sbr_reload {
 	struct mpt3_ioctl_header hdr;
 };
 
+/**
+ * struct mpt3_passthru_command - generic mpt firmware passthru command
+ * @dev_index - device index
+ * @timeout - command timeout in seconds. (if zero then use driver default
+ *  value).
+ * @reply_frame_buf_ptr - MPI reply location
+ * @data_in_buf_ptr - destination for read
+ * @data_out_buf_ptr - data source for write
+ * @max_reply_bytes - maximum number of reply bytes to be sent to app.
+ * @data_in_size - number bytes for data transfer in (read)
+ * @data_out_size - number bytes for data transfer out (write)
+ * @mpi_request - request frame
+ */
+struct mpt3_passthru_command {
+	u8 dev_index;
+	uint32_t timeout;
+	void *reply_frame_buf_ptr;
+	void *data_in_buf_ptr;
+	void *data_out_buf_ptr;
+	uint32_t max_reply_bytes;
+	uint32_t data_in_size;
+	uint32_t data_out_size;
+	Mpi26MctpPassthroughRequest_t *mpi_request;
+};
+
+/*
+ * mpt3sas_get_device_count - Retrieve the count of MCTP passthrough
+ *			      capable devices managed by the driver.
+ *
+ * Returns number of devices that support MCTP passthrough.
+ */
+int mpt3sas_get_device_count(void);
+
+/*
+ * mpt3sas_send_passthru_cmd - Send an MPI MCTP passthrough command to
+ *			       firmware
+ * @command: The MPI MCTP passthrough command to send to firmware
+ *
+ * Returns 0 on success, anything else is error .
+ */
+int mpt3sas_send_mctp_passthru_req(struct mpt3_passthru_command *command);
+
 #endif /* MPT3SAS_CTL_H_INCLUDED */