path: root/drivers/thunderbolt/icm.c

/*
 * Internal Thunderbolt Connection Manager. This is a firmware running on
 * the Thunderbolt host controller performing most of the low-level
 * handling.
 *
 * Copyright (C) 2017, Intel Corporation
 * Authors: Michael Jamet <michael.jamet@intel.com>
 *          Mika Westerberg <mika.westerberg@linux.intel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/pci.h>
#include <linux/platform_data/x86/apple.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

#include "ctl.h"
#include "nhi_regs.h"
#include "tb.h"

#define PCIE2CIO_CMD			0x30
#define PCIE2CIO_CMD_TIMEOUT		BIT(31)
#define PCIE2CIO_CMD_START		BIT(30)
#define PCIE2CIO_CMD_WRITE		BIT(21)
#define PCIE2CIO_CMD_CS_MASK		GENMASK(20, 19)
#define PCIE2CIO_CMD_CS_SHIFT		19
#define PCIE2CIO_CMD_PORT_MASK		GENMASK(18, 13)
#define PCIE2CIO_CMD_PORT_SHIFT		13

#define PCIE2CIO_WRDATA			0x34
#define PCIE2CIO_RDDATA			0x38

#define PHY_PORT_CS1			0x37
#define PHY_PORT_CS1_LINK_DISABLE	BIT(14)
#define PHY_PORT_CS1_LINK_STATE_MASK	GENMASK(29, 26)
#define PHY_PORT_CS1_LINK_STATE_SHIFT	26

#define ICM_TIMEOUT			5000 /* ms */
#define ICM_MAX_LINK			4
#define ICM_MAX_DEPTH			6

/**
 * struct icm - Internal connection manager private data
 * @request_lock: Makes sure only one message is send to ICM at time
 * @rescan_work: Work used to rescan the surviving switches after resume
 * @upstream_port: Pointer to the PCIe upstream port this host
 *		   controller is connected. This is only set for systems
 *		   where ICM needs to be started manually
 * @vnd_cap: Vendor defined capability where PCIe2CIO mailbox resides
 *	     (only set when @upstream_port is not %NULL)
 * @safe_mode: ICM is in safe mode
 * @is_supported: Checks if we can support ICM on this controller
 * @get_mode: Read and return the ICM firmware mode (optional)
 * @get_route: Find a route string for given switch
 * @device_connected: Handle device connected ICM message
 * @device_disconnected: Handle device disconnected ICM message
 */
struct icm {
	struct mutex request_lock;
	struct delayed_work rescan_work;
	struct pci_dev *upstream_port;
	int vnd_cap;
	bool safe_mode;
	bool (*is_supported)(struct tb *tb);
	int (*get_mode)(struct tb *tb);
	int (*get_route)(struct tb *tb, u8 link, u8 depth, u64 *route);
	void (*device_connected)(struct tb *tb,
				 const struct icm_pkg_header *hdr);
	void (*device_disconnected)(struct tb *tb,
				    const struct icm_pkg_header *hdr);
};

struct icm_notification {
	struct work_struct work;
	struct icm_pkg_header *pkg;
	struct tb *tb;
};

static inline struct tb *icm_to_tb(struct icm *icm)
{
	return ((void *)icm - sizeof(struct tb));
}

static inline u8 phy_port_from_route(u64 route, u8 depth)
{
	return tb_switch_phy_port_from_link(route >> ((depth - 1) * 8));
}

static inline u8 dual_link_from_link(u8 link)
{
	return link ? ((link - 1) ^ 0x01) + 1 : 0;
}

static inline u64 get_route(u32 route_hi, u32 route_lo)
{
	return (u64)route_hi << 32 | route_lo;
}

static bool icm_match(const struct tb_cfg_request *req,
		      const struct ctl_pkg *pkg)
{
	const struct icm_pkg_header *res_hdr = pkg->buffer;
	const struct icm_pkg_header *req_hdr = req->request;

	if (pkg->frame.eof != req->response_type)
		return false;
	if (res_hdr->code != req_hdr->code)
		return false;

	return true;
}

static bool icm_copy(struct tb_cfg_request *req, const struct ctl_pkg *pkg)
{
	const struct icm_pkg_header *hdr = pkg->buffer;

	if (hdr->packet_id < req->npackets) {
		size_t offset = hdr->packet_id * req->response_size;

		memcpy(req->response + offset, pkg->buffer, req->response_size);
	}

	return hdr->packet_id == hdr->total_packets - 1;
}

static int icm_request(struct tb *tb, const void *request, size_t request_size,
		       void *response, size_t response_size, size_t npackets,
		       unsigned int timeout_msec)
{
	struct icm *icm = tb_priv(tb);
	int retries = 3;

	do {
		struct tb_cfg_request *req;
		struct tb_cfg_result res;

		req = tb_cfg_request_alloc();
		if (!req)
			return -ENOMEM;

		req->match = icm_match;
		req->copy = icm_copy;
		req->request = request;
		req->request_size = request_size;
		req->request_type = TB_CFG_PKG_ICM_CMD;
		req->response = response;
		req->npackets = npackets;
		req->response_size = response_size;
		req->response_type = TB_CFG_PKG_ICM_RESP;

		mutex_lock(&icm->request_lock);
		res = tb_cfg_request_sync(tb->ctl, req, timeout_msec);
		mutex_unlock(&icm->request_lock);

		tb_cfg_request_put(req);

		if (res.err != -ETIMEDOUT)
			return res.err == 1 ? -EIO : res.err;

		usleep_range