731 lines
		
	
	
		
			19 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			731 lines
		
	
	
		
			19 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
 | |
| /*
 | |
|  * Data Object Exchange
 | |
|  *	PCIe r6.0, sec 6.30 DOE
 | |
|  *
 | |
|  * Copyright (C) 2021 Huawei
 | |
|  *	Jonathan Cameron <Jonathan.Cameron@huawei.com>
 | |
|  *
 | |
|  * Copyright (C) 2022 Intel Corporation
 | |
|  *	Ira Weiny <ira.weiny@intel.com>
 | |
|  */
 | |
| 
 | |
| #define dev_fmt(fmt) "DOE: " fmt
 | |
| 
 | |
| #include <linux/bitfield.h>
 | |
| #include <linux/delay.h>
 | |
| #include <linux/jiffies.h>
 | |
| #include <linux/mutex.h>
 | |
| #include <linux/pci.h>
 | |
| #include <linux/pci-doe.h>
 | |
| #include <linux/workqueue.h>
 | |
| 
 | |
| #include "pci.h"
 | |
| 
 | |
| #define PCI_DOE_PROTOCOL_DISCOVERY 0
 | |
| 
 | |
| /* Timeout of 1 second from 6.30.2 Operation, PCI Spec r6.0 */
 | |
| #define PCI_DOE_TIMEOUT HZ
 | |
| #define PCI_DOE_POLL_INTERVAL	(PCI_DOE_TIMEOUT / 128)
 | |
| 
 | |
| #define PCI_DOE_FLAG_CANCEL	0
 | |
| #define PCI_DOE_FLAG_DEAD	1
 | |
| 
 | |
| /* Max data object length is 2^18 dwords */
 | |
| #define PCI_DOE_MAX_LENGTH	(1 << 18)
 | |
| 
 | |
| /**
 | |
|  * struct pci_doe_mb - State for a single DOE mailbox
 | |
|  *
 | |
|  * This state is used to manage a single DOE mailbox capability.  All fields
 | |
|  * should be considered opaque to the consumers and the structure passed into
 | |
|  * the helpers below after being created by pci_doe_create_mb().
 | |
|  *
 | |
|  * @pdev: PCI device this mailbox belongs to
 | |
|  * @cap_offset: Capability offset
 | |
|  * @prots: Array of protocols supported (encoded as long values)
 | |
|  * @wq: Wait queue for work item
 | |
|  * @work_queue: Queue of pci_doe_work items
 | |
|  * @flags: Bit array of PCI_DOE_FLAG_* flags
 | |
|  */
 | |
| struct pci_doe_mb {
 | |
| 	struct pci_dev *pdev;
 | |
| 	u16 cap_offset;
 | |
| 	struct xarray prots;
 | |
| 
 | |
| 	wait_queue_head_t wq;
 | |
| 	struct workqueue_struct *work_queue;
 | |
| 	unsigned long flags;
 | |
| };
 | |
| 
 | |
| struct pci_doe_protocol {
 | |
| 	u16 vid;
 | |
| 	u8 type;
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * struct pci_doe_task - represents a single query/response
 | |
|  *
 | |
|  * @prot: DOE Protocol
 | |
|  * @request_pl: The request payload
 | |
|  * @request_pl_sz: Size of the request payload (bytes)
 | |
|  * @response_pl: The response payload
 | |
|  * @response_pl_sz: Size of the response payload (bytes)
 | |
|  * @rv: Return value.  Length of received response or error (bytes)
 | |
|  * @complete: Called when task is complete
 | |
|  * @private: Private data for the consumer
 | |
|  * @work: Used internally by the mailbox
 | |
|  * @doe_mb: Used internally by the mailbox
 | |
|  */
 | |
| struct pci_doe_task {
 | |
| 	struct pci_doe_protocol prot;
 | |
| 	const __le32 *request_pl;
 | |
| 	size_t request_pl_sz;
 | |
| 	__le32 *response_pl;
 | |
| 	size_t response_pl_sz;
 | |
| 	int rv;
 | |
| 	void (*complete)(struct pci_doe_task *task);
 | |
| 	void *private;
 | |
| 
 | |
| 	/* initialized by pci_doe_submit_task() */
 | |
| 	struct work_struct work;
 | |
| 	struct pci_doe_mb *doe_mb;
 | |
| };
 | |
| 
 | |
| static int pci_doe_wait(struct pci_doe_mb *doe_mb, unsigned long timeout)
 | |
| {
 | |
| 	if (wait_event_timeout(doe_mb->wq,
 | |
| 			       test_bit(PCI_DOE_FLAG_CANCEL, &doe_mb->flags),
 | |
| 			       timeout))
 | |
| 		return -EIO;
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static void pci_doe_write_ctrl(struct pci_doe_mb *doe_mb, u32 val)
 | |
| {
 | |
| 	struct pci_dev *pdev = doe_mb->pdev;
 | |
| 	int offset = doe_mb->cap_offset;
 | |
| 
 | |
| 	pci_write_config_dword(pdev, offset + PCI_DOE_CTRL, val);
 | |
| }
 | |
| 
 | |
| static int pci_doe_abort(struct pci_doe_mb *doe_mb)
 | |
| {
 | |
| 	struct pci_dev *pdev = doe_mb->pdev;
 | |
| 	int offset = doe_mb->cap_offset;
 | |
| 	unsigned long timeout_jiffies;
 | |
| 
 | |
| 	pci_dbg(pdev, "[%x] Issuing Abort\n", offset);
 | |
| 
 | |
| 	timeout_jiffies = jiffies + PCI_DOE_TIMEOUT;
 | |
| 	pci_doe_write_ctrl(doe_mb, PCI_DOE_CTRL_ABORT);
 | |
| 
 | |
| 	do {
 | |
| 		int rc;
 | |
| 		u32 val;
 | |
| 
 | |
| 		rc = pci_doe_wait(doe_mb, PCI_DOE_POLL_INTERVAL);
 | |
| 		if (rc)
 | |
| 			return rc;
 | |
| 		pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
 | |
| 
 | |
| 		/* Abort success! */
 | |
| 		if (!FIELD_GET(PCI_DOE_STATUS_ERROR, val) &&
 | |
| 		    !FIELD_GET(PCI_DOE_STATUS_BUSY, val))
 | |
| 			return 0;
 | |
| 
 | |
| 	} while (!time_after(jiffies, timeout_jiffies));
 | |
| 
 | |
| 	/* Abort has timed out and the MB is dead */
 | |
| 	pci_err(pdev, "[%x] ABORT timed out\n", offset);
 | |
| 	return -EIO;
 | |
| }
 | |
| 
 | |
| static int pci_doe_send_req(struct pci_doe_mb *doe_mb,
 | |
| 			    struct pci_doe_task *task)
 | |
| {
 | |
| 	struct pci_dev *pdev = doe_mb->pdev;
 | |
| 	int offset = doe_mb->cap_offset;
 | |
| 	size_t length, remainder;
 | |
| 	u32 val;
 | |
| 	int i;
 | |
| 
 | |
| 	/*
 | |
| 	 * Check the DOE busy bit is not set. If it is set, this could indicate
 | |
| 	 * someone other than Linux (e.g. firmware) is using the mailbox. Note
 | |
| 	 * it is expected that firmware and OS will negotiate access rights via
 | |
| 	 * an, as yet to be defined, method.
 | |
| 	 */
 | |
| 	pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
 | |
| 	if (FIELD_GET(PCI_DOE_STATUS_BUSY, val))
 | |
| 		return -EBUSY;
 | |
| 
 | |
| 	if (FIELD_GET(PCI_DOE_STATUS_ERROR, val))
 | |
| 		return -EIO;
 | |
| 
 | |
| 	/* Length is 2 DW of header + length of payload in DW */
 | |
| 	length = 2 + DIV_ROUND_UP(task->request_pl_sz, sizeof(__le32));
 | |
| 	if (length > PCI_DOE_MAX_LENGTH)
 | |
| 		return -EIO;
 | |
| 	if (length == PCI_DOE_MAX_LENGTH)
 | |
| 		length = 0;
 | |
| 
 | |
| 	/* Write DOE Header */
 | |
| 	val = FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_VID, task->prot.vid) |
 | |
| 		FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, task->prot.type);
 | |
| 	pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, val);
 | |
| 	pci_write_config_dword(pdev, offset + PCI_DOE_WRITE,
 | |
| 			       FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH,
 | |
| 					  length));
 | |
| 
 | |
| 	/* Write payload */
 | |
| 	for (i = 0; i < task->request_pl_sz / sizeof(__le32); i++)
 | |
| 		pci_write_config_dword(pdev, offset + PCI_DOE_WRITE,
 | |
| 				       le32_to_cpu(task->request_pl[i]));
 | |
| 
 | |
| 	/* Write last payload dword */
 | |
| 	remainder = task->request_pl_sz % sizeof(__le32);
 | |
| 	if (remainder) {
 | |
| 		val = 0;
 | |
| 		memcpy(&val, &task->request_pl[i], remainder);
 | |
| 		le32_to_cpus(&val);
 | |
| 		pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, val);
 | |
| 	}
 | |
| 
 | |
| 	pci_doe_write_ctrl(doe_mb, PCI_DOE_CTRL_GO);
 | |
| 
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static bool pci_doe_data_obj_ready(struct pci_doe_mb *doe_mb)
 | |
| {
 | |
| 	struct pci_dev *pdev = doe_mb->pdev;
 | |
| 	int offset = doe_mb->cap_offset;
 | |
| 	u32 val;
 | |
| 
 | |
| 	pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
 | |
| 	if (FIELD_GET(PCI_DOE_STATUS_DATA_OBJECT_READY, val))
 | |
| 		return true;
 | |
| 	return false;
 | |
| }
 | |
| 
 | |
| static int pci_doe_recv_resp(struct pci_doe_mb *doe_mb, struct pci_doe_task *task)
 | |
| {
 | |
| 	size_t length, payload_length, remainder, received;
 | |
| 	struct pci_dev *pdev = doe_mb->pdev;
 | |
| 	int offset = doe_mb->cap_offset;
 | |
| 	int i = 0;
 | |
| 	u32 val;
 | |
| 
 | |
| 	/* Read the first dword to get the protocol */
 | |
| 	pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val);
 | |
| 	if ((FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val) != task->prot.vid) ||
 | |
| 	    (FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val) != task->prot.type)) {
 | |
| 		dev_err_ratelimited(&pdev->dev, "[%x] expected [VID, Protocol] = [%04x, %02x], got [%04x, %02x]\n",
 | |
| 				    doe_mb->cap_offset, task->prot.vid, task->prot.type,
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| 				    FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val),
 | |
| 				    FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val));
 | |
| 		return -EIO;
 | |
| 	}
 | |
| 
 | |
| 	pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
 | |
| 	/* Read the second dword to get the length */
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| 	pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val);
 | |
| 	pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
 | |
| 
 | |
| 	length = FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH, val);
 | |
| 	/* A value of 0x0 indicates max data object length */
 | |
| 	if (!length)
 | |
| 		length = PCI_DOE_MAX_LENGTH;
 | |
| 	if (length < 2)
 | |
| 		return -EIO;
 | |
| 
 | |
| 	/* First 2 dwords have already been read */
 | |
| 	length -= 2;
 | |
| 	received = task->response_pl_sz;
 | |
| 	payload_length = DIV_ROUND_UP(task->response_pl_sz, sizeof(__le32));
 | |
| 	remainder = task->response_pl_sz % sizeof(__le32);
 | |
| 
 | |
| 	/* remainder signifies number of data bytes in last payload dword */
 | |
| 	if (!remainder)
 | |
| 		remainder = sizeof(__le32);
 | |
| 
 | |
| 	if (length < payload_length) {
 | |
| 		received = length * sizeof(__le32);
 | |
| 		payload_length = length;
 | |
| 		remainder = sizeof(__le32);
 | |
| 	}
 | |
| 
 | |
| 	if (payload_length) {
 | |
| 		/* Read all payload dwords except the last */
 | |
| 		for (; i < payload_length - 1; i++) {
 | |
| 			pci_read_config_dword(pdev, offset + PCI_DOE_READ,
 | |
| 					      &val);
 | |
| 			task->response_pl[i] = cpu_to_le32(val);
 | |
| 			pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
 | |
| 		}
 | |
| 
 | |
| 		/* Read last payload dword */
 | |
| 		pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val);
 | |
| 		cpu_to_le32s(&val);
 | |
| 		memcpy(&task->response_pl[i], &val, remainder);
 | |
| 		/* Prior to the last ack, ensure Data Object Ready */
 | |
| 		if (!pci_doe_data_obj_ready(doe_mb))
 | |
| 			return -EIO;
 | |
| 		pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
 | |
| 		i++;
 | |
| 	}
 | |
| 
 | |
| 	/* Flush excess length */
 | |
| 	for (; i < length; i++) {
 | |
| 		pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val);
 | |
| 		pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
 | |
| 	}
 | |
| 
 | |
| 	/* Final error check to pick up on any since Data Object Ready */
 | |
| 	pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
 | |
| 	if (FIELD_GET(PCI_DOE_STATUS_ERROR, val))
 | |
| 		return -EIO;
 | |
| 
 | |
| 	return received;
 | |
| }
 | |
| 
 | |
| static void signal_task_complete(struct pci_doe_task *task, int rv)
 | |
| {
 | |
| 	task->rv = rv;
 | |
| 	destroy_work_on_stack(&task->work);
 | |
| 	task->complete(task);
 | |
| }
 | |
| 
 | |
| static void signal_task_abort(struct pci_doe_task *task, int rv)
 | |
| {
 | |
| 	struct pci_doe_mb *doe_mb = task->doe_mb;
 | |
| 	struct pci_dev *pdev = doe_mb->pdev;
 | |
| 
 | |
| 	if (pci_doe_abort(doe_mb)) {
 | |
| 		/*
 | |
| 		 * If the device can't process an abort; set the mailbox dead
 | |
| 		 *	- no more submissions
 | |
| 		 */
 | |
| 		pci_err(pdev, "[%x] Abort failed marking mailbox dead\n",
 | |
| 			doe_mb->cap_offset);
 | |
| 		set_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags);
 | |
| 	}
 | |
| 	signal_task_complete(task, rv);
 | |
| }
 | |
| 
 | |
| static void doe_statemachine_work(struct work_struct *work)
 | |
| {
 | |
| 	struct pci_doe_task *task = container_of(work, struct pci_doe_task,
 | |
| 						 work);
 | |
| 	struct pci_doe_mb *doe_mb = task->doe_mb;
 | |
| 	struct pci_dev *pdev = doe_mb->pdev;
 | |
| 	int offset = doe_mb->cap_offset;
 | |
| 	unsigned long timeout_jiffies;
 | |
| 	u32 val;
 | |
| 	int rc;
 | |
| 
 | |
| 	if (test_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags)) {
 | |
| 		signal_task_complete(task, -EIO);
 | |
| 		return;
 | |
| 	}
 | |
| 
 | |
| 	/* Send request */
 | |
| 	rc = pci_doe_send_req(doe_mb, task);
 | |
| 	if (rc) {
 | |
| 		/*
 | |
| 		 * The specification does not provide any guidance on how to
 | |
| 		 * resolve conflicting requests from other entities.
 | |
| 		 * Furthermore, it is likely that busy will not be detected
 | |
| 		 * most of the time.  Flag any detection of status busy with an
 | |
| 		 * error.
 | |
| 		 */
 | |
| 		if (rc == -EBUSY)
 | |
| 			dev_err_ratelimited(&pdev->dev, "[%x] busy detected; another entity is sending conflicting requests\n",
 | |
| 					    offset);
 | |
| 		signal_task_abort(task, rc);
 | |
| 		return;
 | |
| 	}
 | |
| 
 | |
| 	timeout_jiffies = jiffies + PCI_DOE_TIMEOUT;
 | |
| 	/* Poll for response */
 | |
| retry_resp:
 | |
| 	pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
 | |
| 	if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) {
 | |
| 		signal_task_abort(task, -EIO);
 | |
| 		return;
 | |
| 	}
 | |
| 
 | |
| 	if (!FIELD_GET(PCI_DOE_STATUS_DATA_OBJECT_READY, val)) {
 | |
| 		if (time_after(jiffies, timeout_jiffies)) {
 | |
| 			signal_task_abort(task, -EIO);
 | |
| 			return;
 | |
| 		}
 | |
| 		rc = pci_doe_wait(doe_mb, PCI_DOE_POLL_INTERVAL);
 | |
| 		if (rc) {
 | |
| 			signal_task_abort(task, rc);
 | |
| 			return;
 | |
| 		}
 | |
| 		goto retry_resp;
 | |
| 	}
 | |
| 
 | |
| 	rc  = pci_doe_recv_resp(doe_mb, task);
 | |
| 	if (rc < 0) {
 | |
| 		signal_task_abort(task, rc);
 | |
| 		return;
 | |
| 	}
 | |
| 
 | |
| 	signal_task_complete(task, rc);
 | |
| }
 | |
| 
 | |
| static void pci_doe_task_complete(struct pci_doe_task *task)
 | |
| {
 | |
| 	complete(task->private);
 | |
| }
 | |
| 
 | |
| static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 capver, u8 *index, u16 *vid,
 | |
| 			     u8 *protocol)
 | |
| {
 | |
| 	u32 request_pl = FIELD_PREP(PCI_DOE_DATA_OBJECT_DISC_REQ_3_INDEX,
 | |
| 				    *index) |
 | |
| 			 FIELD_PREP(PCI_DOE_DATA_OBJECT_DISC_REQ_3_VER,
 | |
| 				    (capver >= 2) ? 2 : 0);
 | |
| 	__le32 request_pl_le = cpu_to_le32(request_pl);
 | |
| 	__le32 response_pl_le;
 | |
| 	u32 response_pl;
 | |
| 	int rc;
 | |
| 
 | |
| 	rc = pci_doe(doe_mb, PCI_VENDOR_ID_PCI_SIG, PCI_DOE_PROTOCOL_DISCOVERY,
 | |
| 		     &request_pl_le, sizeof(request_pl_le),
 | |
| 		     &response_pl_le, sizeof(response_pl_le));
 | |
| 	if (rc < 0)
 | |
| 		return rc;
 | |
| 
 | |
| 	if (rc != sizeof(response_pl_le))
 | |
| 		return -EIO;
 | |
| 
 | |
| 	response_pl = le32_to_cpu(response_pl_le);
 | |
| 	*vid = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_VID, response_pl);
 | |
| 	*protocol = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL,
 | |
| 			      response_pl);
 | |
| 	*index = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX,
 | |
| 			   response_pl);
 | |
| 
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static void *pci_doe_xa_prot_entry(u16 vid, u8 prot)
 | |
| {
 | |
| 	return xa_mk_value((vid << 8) | prot);
 | |
| }
 | |
| 
 | |
| static int pci_doe_cache_protocols(struct pci_doe_mb *doe_mb)
 | |
| {
 | |
| 	u8 index = 0;
 | |
| 	u8 xa_idx = 0;
 | |
| 	u32 hdr = 0;
 | |
| 
 | |
| 	pci_read_config_dword(doe_mb->pdev, doe_mb->cap_offset, &hdr);
 | |
| 
 | |
| 	do {
 | |
| 		int rc;
 | |
| 		u16 vid;
 | |
| 		u8 prot;
 | |
| 
 | |
| 		rc = pci_doe_discovery(doe_mb, PCI_EXT_CAP_VER(hdr), &index,
 | |
| 				       &vid, &prot);
 | |
| 		if (rc)
 | |
| 			return rc;
 | |
| 
 | |
| 		pci_dbg(doe_mb->pdev,
 | |
| 			"[%x] Found protocol %d vid: %x prot: %x\n",
 | |
| 			doe_mb->cap_offset, xa_idx, vid, prot);
 | |
| 
 | |
| 		rc = xa_insert(&doe_mb->prots, xa_idx++,
 | |
| 			       pci_doe_xa_prot_entry(vid, prot), GFP_KERNEL);
 | |
| 		if (rc)
 | |
| 			return rc;
 | |
| 	} while (index);
 | |
| 
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static void pci_doe_cancel_tasks(struct pci_doe_mb *doe_mb)
 | |
| {
 | |
| 	/* Stop all pending work items from starting */
 | |
| 	set_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags);
 | |
| 
 | |
| 	/* Cancel an in progress work item, if necessary */
 | |
| 	set_bit(PCI_DOE_FLAG_CANCEL, &doe_mb->flags);
 | |
| 	wake_up(&doe_mb->wq);
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * pci_doe_create_mb() - Create a DOE mailbox object
 | |
|  *
 | |
|  * @pdev: PCI device to create the DOE mailbox for
 | |
|  * @cap_offset: Offset of the DOE mailbox
 | |
|  *
 | |
|  * Create a single mailbox object to manage the mailbox protocol at the
 | |
|  * cap_offset specified.
 | |
|  *
 | |
|  * RETURNS: created mailbox object on success
 | |
|  *	    ERR_PTR(-errno) on failure
 | |
|  */
 | |
| static struct pci_doe_mb *pci_doe_create_mb(struct pci_dev *pdev,
 | |
| 					    u16 cap_offset)
 | |
| {
 | |
| 	struct pci_doe_mb *doe_mb;
 | |
| 	int rc;
 | |
| 
 | |
| 	doe_mb = kzalloc(sizeof(*doe_mb), GFP_KERNEL);
 | |
| 	if (!doe_mb)
 | |
| 		return ERR_PTR(-ENOMEM);
 | |
| 
 | |
| 	doe_mb->pdev = pdev;
 | |
| 	doe_mb->cap_offset = cap_offset;
 | |
| 	init_waitqueue_head(&doe_mb->wq);
 | |
| 	xa_init(&doe_mb->prots);
 | |
| 
 | |
| 	doe_mb->work_queue = alloc_ordered_workqueue("%s %s DOE [%x]", 0,
 | |
| 						dev_bus_name(&pdev->dev),
 | |
| 						pci_name(pdev),
 | |
| 						doe_mb->cap_offset);
 | |
| 	if (!doe_mb->work_queue) {
 | |
| 		pci_err(pdev, "[%x] failed to allocate work queue\n",
 | |
| 			doe_mb->cap_offset);
 | |
| 		rc = -ENOMEM;
 | |
| 		goto err_free;
 | |
| 	}
 | |
| 
 | |
| 	/* Reset the mailbox by issuing an abort */
 | |
| 	rc = pci_doe_abort(doe_mb);
 | |
| 	if (rc) {
 | |
| 		pci_err(pdev, "[%x] failed to reset mailbox with abort command : %d\n",
 | |
| 			doe_mb->cap_offset, rc);
 | |
| 		goto err_destroy_wq;
 | |
| 	}
 | |
| 
 | |
| 	/*
 | |
| 	 * The state machine and the mailbox should be in sync now;
 | |
| 	 * Use the mailbox to query protocols.
 | |
| 	 */
 | |
| 	rc = pci_doe_cache_protocols(doe_mb);
 | |
| 	if (rc) {
 | |
| 		pci_err(pdev, "[%x] failed to cache protocols : %d\n",
 | |
| 			doe_mb->cap_offset, rc);
 | |
| 		goto err_cancel;
 | |
| 	}
 | |
| 
 | |
| 	return doe_mb;
 | |
| 
 | |
| err_cancel:
 | |
| 	pci_doe_cancel_tasks(doe_mb);
 | |
| 	xa_destroy(&doe_mb->prots);
 | |
| err_destroy_wq:
 | |
| 	destroy_workqueue(doe_mb->work_queue);
 | |
| err_free:
 | |
| 	kfree(doe_mb);
 | |
| 	return ERR_PTR(rc);
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * pci_doe_destroy_mb() - Destroy a DOE mailbox object
 | |
|  *
 | |
|  * @doe_mb: DOE mailbox
 | |
|  *
 | |
|  * Destroy all internal data structures created for the DOE mailbox.
 | |
|  */
 | |
| static void pci_doe_destroy_mb(struct pci_doe_mb *doe_mb)
 | |
| {
 | |
| 	pci_doe_cancel_tasks(doe_mb);
 | |
| 	xa_destroy(&doe_mb->prots);
 | |
| 	destroy_workqueue(doe_mb->work_queue);
 | |
| 	kfree(doe_mb);
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * pci_doe_supports_prot() - Return if the DOE instance supports the given
 | |
|  *			     protocol
 | |
|  * @doe_mb: DOE mailbox capability to query
 | |
|  * @vid: Protocol Vendor ID
 | |
|  * @type: Protocol type
 | |
|  *
 | |
|  * RETURNS: True if the DOE mailbox supports the protocol specified
 | |
|  */
 | |
| static bool pci_doe_supports_prot(struct pci_doe_mb *doe_mb, u16 vid, u8 type)
 | |
| {
 | |
| 	unsigned long index;
 | |
| 	void *entry;
 | |
| 
 | |
| 	/* The discovery protocol must always be supported */
 | |
| 	if (vid == PCI_VENDOR_ID_PCI_SIG && type == PCI_DOE_PROTOCOL_DISCOVERY)
 | |
| 		return true;
 | |
| 
 | |
| 	xa_for_each(&doe_mb->prots, index, entry)
 | |
| 		if (entry == pci_doe_xa_prot_entry(vid, type))
 | |
| 			return true;
 | |
| 
 | |
| 	return false;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * pci_doe_submit_task() - Submit a task to be processed by the state machine
 | |
|  *
 | |
|  * @doe_mb: DOE mailbox capability to submit to
 | |
|  * @task: task to be queued
 | |
|  *
 | |
|  * Submit a DOE task (request/response) to the DOE mailbox to be processed.
 | |
|  * Returns upon queueing the task object.  If the queue is full this function
 | |
|  * will sleep until there is room in the queue.
 | |
|  *
 | |
|  * task->complete will be called when the state machine is done processing this
 | |
|  * task.
 | |
|  *
 | |
|  * @task must be allocated on the stack.
 | |
|  *
 | |
|  * Excess data will be discarded.
 | |
|  *
 | |
|  * RETURNS: 0 when task has been successfully queued, -ERRNO on error
 | |
|  */
 | |
| static int pci_doe_submit_task(struct pci_doe_mb *doe_mb,
 | |
| 			       struct pci_doe_task *task)
 | |
| {
 | |
| 	if (!pci_doe_supports_prot(doe_mb, task->prot.vid, task->prot.type))
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	if (test_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags))
 | |
| 		return -EIO;
 | |
| 
 | |
| 	task->doe_mb = doe_mb;
 | |
| 	INIT_WORK_ONSTACK(&task->work, doe_statemachine_work);
 | |
| 	queue_work(doe_mb->work_queue, &task->work);
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * pci_doe() - Perform Data Object Exchange
 | |
|  *
 | |
|  * @doe_mb: DOE Mailbox
 | |
|  * @vendor: Vendor ID
 | |
|  * @type: Data Object Type
 | |
|  * @request: Request payload
 | |
|  * @request_sz: Size of request payload (bytes)
 | |
|  * @response: Response payload
 | |
|  * @response_sz: Size of response payload (bytes)
 | |
|  *
 | |
|  * Submit @request to @doe_mb and store the @response.
 | |
|  * The DOE exchange is performed synchronously and may therefore sleep.
 | |
|  *
 | |
|  * Payloads are treated as opaque byte streams which are transmitted verbatim,
 | |
|  * without byte-swapping.  If payloads contain little-endian register values,
 | |
|  * the caller is responsible for conversion with cpu_to_le32() / le32_to_cpu().
 | |
|  *
 | |
|  * For convenience, arbitrary payload sizes are allowed even though PCIe r6.0
 | |
|  * sec 6.30.1 specifies the Data Object Header 2 "Length" in dwords.  The last
 | |
|  * (partial) dword is copied with byte granularity and padded with zeroes if
 | |
|  * necessary.  Callers are thus relieved of using dword-sized bounce buffers.
 | |
|  *
 | |
|  * RETURNS: Length of received response or negative errno.
 | |
|  * Received data in excess of @response_sz is discarded.
 | |
|  * The length may be smaller than @response_sz and the caller
 | |
|  * is responsible for checking that.
 | |
|  */
 | |
| int pci_doe(struct pci_doe_mb *doe_mb, u16 vendor, u8 type,
 | |
| 	    const void *request, size_t request_sz,
 | |
| 	    void *response, size_t response_sz)
 | |
| {
 | |
| 	DECLARE_COMPLETION_ONSTACK(c);
 | |
| 	struct pci_doe_task task = {
 | |
| 		.prot.vid = vendor,
 | |
| 		.prot.type = type,
 | |
| 		.request_pl = request,
 | |
| 		.request_pl_sz = request_sz,
 | |
| 		.response_pl = response,
 | |
| 		.response_pl_sz = response_sz,
 | |
| 		.complete = pci_doe_task_complete,
 | |
| 		.private = &c,
 | |
| 	};
 | |
| 	int rc;
 | |
| 
 | |
| 	rc = pci_doe_submit_task(doe_mb, &task);
 | |
| 	if (rc)
 | |
| 		return rc;
 | |
| 
 | |
| 	wait_for_completion(&c);
 | |
| 
 | |
| 	return task.rv;
 | |
| }
 | |
| EXPORT_SYMBOL_GPL(pci_doe);
 | |
| 
 | |
| /**
 | |
|  * pci_find_doe_mailbox() - Find Data Object Exchange mailbox
 | |
|  *
 | |
|  * @pdev: PCI device
 | |
|  * @vendor: Vendor ID
 | |
|  * @type: Data Object Type
 | |
|  *
 | |
|  * Find first DOE mailbox of a PCI device which supports the given protocol.
 | |
|  *
 | |
|  * RETURNS: Pointer to the DOE mailbox or NULL if none was found.
 | |
|  */
 | |
| struct pci_doe_mb *pci_find_doe_mailbox(struct pci_dev *pdev, u16 vendor,
 | |
| 					u8 type)
 | |
| {
 | |
| 	struct pci_doe_mb *doe_mb;
 | |
| 	unsigned long index;
 | |
| 
 | |
| 	xa_for_each(&pdev->doe_mbs, index, doe_mb)
 | |
| 		if (pci_doe_supports_prot(doe_mb, vendor, type))
 | |
| 			return doe_mb;
 | |
| 
 | |
| 	return NULL;
 | |
| }
 | |
| EXPORT_SYMBOL_GPL(pci_find_doe_mailbox);
 | |
| 
 | |
| void pci_doe_init(struct pci_dev *pdev)
 | |
| {
 | |
| 	struct pci_doe_mb *doe_mb;
 | |
| 	u16 offset = 0;
 | |
| 	int rc;
 | |
| 
 | |
| 	xa_init(&pdev->doe_mbs);
 | |
| 
 | |
| 	while ((offset = pci_find_next_ext_capability(pdev, offset,
 | |
| 						      PCI_EXT_CAP_ID_DOE))) {
 | |
| 		doe_mb = pci_doe_create_mb(pdev, offset);
 | |
| 		if (IS_ERR(doe_mb)) {
 | |
| 			pci_err(pdev, "[%x] failed to create mailbox: %ld\n",
 | |
| 				offset, PTR_ERR(doe_mb));
 | |
| 			continue;
 | |
| 		}
 | |
| 
 | |
| 		rc = xa_insert(&pdev->doe_mbs, offset, doe_mb, GFP_KERNEL);
 | |
| 		if (rc) {
 | |
| 			pci_err(pdev, "[%x] failed to insert mailbox: %d\n",
 | |
| 				offset, rc);
 | |
| 			pci_doe_destroy_mb(doe_mb);
 | |
| 		}
 | |
| 	}
 | |
| }
 | |
| 
 | |
| void pci_doe_destroy(struct pci_dev *pdev)
 | |
| {
 | |
| 	struct pci_doe_mb *doe_mb;
 | |
| 	unsigned long index;
 | |
| 
 | |
| 	xa_for_each(&pdev->doe_mbs, index, doe_mb)
 | |
| 		pci_doe_destroy_mb(doe_mb);
 | |
| 
 | |
| 	xa_destroy(&pdev->doe_mbs);
 | |
| }
 | |
| 
 | |
| void pci_doe_disconnected(struct pci_dev *pdev)
 | |
| {
 | |
| 	struct pci_doe_mb *doe_mb;
 | |
| 	unsigned long index;
 | |
| 
 | |
| 	xa_for_each(&pdev->doe_mbs, index, doe_mb)
 | |
| 		pci_doe_cancel_tasks(doe_mb);
 | |
| }
 |