path: root/drivers/cdx/controller/mcdi.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Management-Controller-to-Driver Interface
 *
 * Copyright 2008-2013 Solarflare Communications Inc.
 * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
 */
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/if_vlan.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/device.h>
#include <linux/rwsem.h>
#include <linux/vmalloc.h>
#include <net/netevent.h>
#include <linux/log2.h>
#include <linux/net_tstamp.h>
#include <linux/wait.h>

#include "bitfield.h"
#include "mcdi.h"

struct cdx_mcdi_copy_buffer {
	struct cdx_dword buffer[DIV_ROUND_UP(MCDI_CTL_SDU_LEN_MAX, 4)];
};

#ifdef CONFIG_MCDI_LOGGING
#define LOG_LINE_MAX		(1024 - 32)
#endif

static void cdx_mcdi_cancel_cmd(struct cdx_mcdi *cdx, struct cdx_mcdi_cmd *cmd);
static void cdx_mcdi_wait_for_cleanup(struct cdx_mcdi *cdx);
static int cdx_mcdi_rpc_async_internal(struct cdx_mcdi *cdx,
				       struct cdx_mcdi_cmd *cmd,
				       unsigned int *handle);
static void cdx_mcdi_start_or_queue(struct cdx_mcdi_iface *mcdi,
				    bool allow_retry);
static void cdx_mcdi_cmd_start_or_queue(struct cdx_mcdi_iface *mcdi,
					struct cdx_mcdi_cmd *cmd);
static bool cdx_mcdi_complete_cmd(struct cdx_mcdi_iface *mcdi,
				  struct cdx_mcdi_cmd *cmd,
				  struct cdx_dword *outbuf,
				  int len,
				  struct list_head *cleanup_list);
static void cdx_mcdi_timeout_cmd(struct cdx_mcdi_iface *mcdi,
				 struct cdx_mcdi_cmd *cmd,
				 struct list_head *cleanup_list);
static void cdx_mcdi_cmd_work(struct work_struct *context);
static void cdx_mcdi_mode_fail(struct cdx_mcdi *cdx, struct list_head *cleanup_list);
static void _cdx_mcdi_display_error(struct cdx_mcdi *cdx, unsigned int cmd,
				    size_t inlen, int raw, int arg, int err_no);

static bool cdx_cmd_cancelled(struct cdx_mcdi_cmd *cmd)
{
	return cmd->state == MCDI_STATE_RUNNING_CANCELLED;
}

static void cdx_mcdi_cmd_release(struct kref *ref)
{
	kfree(container_of(ref, struct cdx_mcdi_cmd, ref));
}

static unsigned int cdx_mcdi_cmd_handle(struct cdx_mcdi_cmd *cmd)
{
	return cmd->handle;
}

static void _cdx_mcdi_remove_cmd(struct cdx_mcdi_iface *mcdi,
				 struct cdx_mcdi_cmd *cmd,
				 struct list_head *cleanup_list)
{
	/* if cancelled, the completers have already been called */
	if (cdx_cmd_cancelled(cmd))
		return;

	if (cmd->completer) {
		list_add_tail(&cmd->cleanup_list, cleanup_list);
		++mcdi->outstanding_cleanups;
		kref_get(&cmd->ref);
	}
}

static void cdx_mcdi_remove_cmd(struct cdx_mcdi_iface *mcdi,
				struct cdx_mcdi_cmd *cmd,
				struct list_head *cleanup_list)
{
	list_del(&cmd->list);
	_cdx_mcdi_remove_cmd(mcdi, cmd, cleanup_list);
	cmd->state = MCDI_STATE_FINISHED;
	kref_put(&cmd->ref, cdx_mcdi_cmd_release);
	if (list_empty(&mcdi->cmd_list))
		wake_up(&mcdi->cmd_complete_wq);
}

static unsigned long cdx_mcdi_rpc_timeout(struct cdx_mcdi *cdx, unsigned int cmd)
{
	if (!cdx->mcdi_ops->mcdi_rpc_timeout)
		return MCDI_RPC_TIMEOUT;
	else
		return cdx->mcdi_ops->mcdi_rpc_timeout(cdx, cmd);
}

int cdx_mcdi_init(struct cdx_mcdi *cdx)
{
	struct cdx_mcdi_iface *mcdi;
	int rc = -ENOMEM;

	cdx->mcdi = kzalloc(sizeof(*cdx->mcdi), GFP_KERNEL);
	if (!cdx->mcdi)
		goto fail;

	mcdi = cdx_mcdi_if(cdx);
	mcdi->cdx = cdx;

#ifdef CONFIG_MCDI_LOGGING
	mcdi->logging_buffer = kmalloc(LOG_LINE_MAX, GFP_KERNEL);
	if (!mcdi->logging_buffer)
		goto fail2;
#endif
	mcdi->workqueue = alloc_ordered_workqueue("mcdi_wq", 0);
	if (!mcdi->workqueue)
		goto fail3;
	mutex_init(&mcdi->iface_lock);
	mcdi->mode = MCDI_MODE_EVENTS;
	INIT_LIST_HEAD(&mcdi->cmd_list);
	init_waitqueue_head(&mcdi->cmd_complete_wq);

	mcdi->new_epoch = true;

	return 0;
fail3:
#ifdef CONFIG_MCDI_LOGGING
	kfree(mcdi->logging_buffer);
fail2:
#endif
	kfree(cdx->mcdi);
	cdx->mcdi = NULL;
fail:
	return rc;
}

void cdx_mcdi_finish(struct cdx_mcdi *cdx)
{
	struct cdx_mcdi_iface *mcdi;

	mcdi = cdx_mcdi_if(cdx);
	if (!mcdi)
		return;

	cdx_mcdi_wait_for_cleanup(cdx