/*
  This file is provided under a dual BSD/GPLv2 license.  When using or
  redistributing this file, you may do so under either license.

  GPL LICENSE SUMMARY
  Copyright(c) 2015 Intel Corporation.
  This program is free software; you can redistribute it and/or modify
  it under the terms of version 2 of the GNU General Public License as
  published by the Free Software Foundation.

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  Contact Information:
  qat-linux@intel.com

  BSD LICENSE
  Copyright(c) 2015 Intel Corporation.
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:

    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in
      the documentation and/or other materials provided with the
      distribution.
    * Neither the name of Intel Corporation nor the names of its
      contributors may be used to endorse or promote products derived
      from this software without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <linux/workqueue.h>
#include <linux/pci.h>
#include <linux/device.h>
#include <linux/iommu.h>
#include "adf_common_drv.h"
#include "adf_cfg.h"
#include "adf_pf2vf_msg.h"

static struct workqueue_struct *pf2vf_resp_wq;

#define ME2FUNCTION_MAP_A_OFFSET	(0x3A400 + 0x190)
#define ME2FUNCTION_MAP_A_NUM_REGS	96

#define ME2FUNCTION_MAP_B_OFFSET	(0x3A400 + 0x310)
#define ME2FUNCTION_MAP_B_NUM_REGS	12

#define ME2FUNCTION_MAP_REG_SIZE	4
#define ME2FUNCTION_MAP_VALID		BIT(7)

#define READ_CSR_ME2FUNCTION_MAP_A(pmisc_bar_addr, index)		\
	ADF_CSR_RD(pmisc_bar_addr, ME2FUNCTION_MAP_A_OFFSET +		\
		   ME2FUNCTION_MAP_REG_SIZE * index)

#define WRITE_CSR_ME2FUNCTION_MAP_A(pmisc_bar_addr, index, value)	\
	ADF_CSR_WR(pmisc_bar_addr, ME2FUNCTION_MAP_A_OFFSET +		\
		   ME2FUNCTION_MAP_REG_SIZE * index, value)

#define READ_CSR_ME2FUNCTION_MAP_B(pmisc_bar_addr, index)		\
	ADF_CSR_RD(pmisc_bar_addr, ME2FUNCTION_MAP_B_OFFSET +		\
		   ME2FUNCTION_MAP_REG_SIZE * index)

#define WRITE_CSR_ME2FUNCTION_MAP_B(pmisc_bar_addr, index, value)	\
	ADF_CSR_WR(pmisc_bar_addr, ME2FUNCTION_MAP_B_OFFSET +		\
		   ME2FUNCTION_MAP_REG_SIZE * index, value)

struct adf_pf2vf_resp {
	struct work_struct pf2vf_resp_work;
	struct adf_accel_vf_info *vf_info;
};

static void adf_iov_send_resp(struct work_struct *work)
{
	struct adf_pf2vf_resp *pf2vf_resp =
		container_of(work, struct adf_pf2vf_resp, pf2vf_resp_work);

	adf_vf2pf_req_hndl(pf2vf_resp->vf_info);
	kfree(pf2vf_resp);
}

static void adf_vf2pf_bh_handler(void *data)
{
	struct adf_accel_vf_info *vf_info = (struct adf_accel_vf_info *)data;
	struct adf_pf2vf_resp *pf2vf_resp;

	pf2vf_resp = kzalloc(sizeof(*pf2vf_resp), GFP_ATOMIC);
	if (!pf2vf_resp)
		return;

	pf2vf_resp->vf_info = vf_info;
	INIT_WORK(&pf2vf_resp->pf2vf_resp_work, adf_iov_send_resp);
	queue_work(pf2vf_resp_wq, &pf2vf_resp->pf2vf_resp_work);
}

static int adf_enable_sriov(struct adf_accel_dev *accel_dev)
{
	struct pci_dev *pdev = accel_to_pci_dev(accel_dev);
	int totalvfs = pci_sriov_get_totalvfs(pdev);
	struct adf_hw_device_data *hw_data = accel_dev->hw_device;
	struct adf_bar *pmisc =
			&GET_BARS(accel_dev)[hw_data->get_misc_bar_id(hw_data)];
	void __iomem *pmisc_addr = pmisc->virt_addr;
	struct adf_accel_vf_info *vf_info;
	int i;
	u32 reg;

	for (i = 0, vf_info = accel_dev->pf.vf_info; i < totalvfs;
	     i++, vf_info++) {
		/* This ptr will be populated when VFs will be created */
		vf_info->accel_dev = accel_dev;
		vf_info->vf_nr = i;

		tasklet_init(&vf_info->vf2pf_bh_tasklet,
			     (void *)adf_vf2pf_bh_handler,
			     (unsigned long)vf_info);
		mutex_init(&vf_info->pf2vf_lock);
		ratelimit_state_init(&vf_info->vf2pf_ratelimit,
				     DEFAULT_RATELIMIT_INTERVAL,
				     DEFAULT_RATELIMIT_BURST);
	}

	/* Set Valid bits in ME Thread to PCIe Function Mapping Group A */
	for (i = 0; i < ME2FUNCTION_MAP_A_NUM_REGS; i++) {
		reg = READ_CSR_ME2FUNCTION_MAP_A(pmisc_addr, i);
		reg |= ME2FUNCTION_MAP_VALID;
		WRITE_CSR_ME2FUNCTION_MAP_A(pmisc_addr, i, reg);
	}

	/* Set Valid bits in ME Thread to PCIe Function Mapping Group B */
	for (i = 0; i < ME2FUNCTION_MAP_B_NUM_REGS; i++) {
		reg = READ_CSR_ME2FUNCTION_MAP_B(pmisc_addr, i);
		reg |= ME2FUNCTION_MAP_VALID;
		WRITE_CSR_ME2FUNCTION_MAP_B(pmisc_addr, i, reg);
	}

	/* Enable VF to PF interrupts for all VFs */
	adf_enable_vf2pf_interrupts(accel_dev, GENMASK_ULL(totalvfs - 1, 0));

	/*
	 * Due to the hardware design, when SR-IOV and the ring arbiter
	 * are enabled all the VFs supported in hardware must be enabled in
	 * order for all the hardware resources (i.e. bundles) to be usable.
	 * When SR-IOV is enabled, each of the VFs will own one bundle.
	 */
	return pci_enable_sriov(pdev, totalvfs);
}

/**
 * adf_disable_sriov() - Disable SRIOV for the device
 * @accel_dev:  Pointer to accel device.
 *
 * Function disables SRIOV for the accel device.
 *
 * Return: 0 on success, error code otherwise.
 */
void adf_disable_sriov(struct adf_accel_dev *accel_dev)
{
	struct adf_hw_device_data *hw_data = accel_dev->hw_device;
	struct adf_bar *pmisc =
			&GET_BARS(accel_dev)[hw_data->get_misc_bar_id(hw_data)];
	void __iomem *pmisc_addr = pmisc->virt_addr;
	int totalvfs = pci_sriov_get_totalvfs(accel_to_pci_dev(accel_dev));
	struct adf_accel_vf_info *vf;
	u32 reg;
	int i;

	if (!accel_dev->pf.vf_info)
		return;

	adf_pf2vf_notify_restarting(accel_dev);

	pci_disable_sriov(accel_to_pci_dev(accel_dev));

	/* Disable VF to PF interrupts */
	adf_disable_vf2pf_interrupts(accel_dev, 0xFFFFFFFF);

	/* Clear Valid bits in ME Thread to PCIe Function Mapping Group A */
	for (i = 0; i < ME2FUNCTION_MAP_A_NUM_REGS; i++) {
		reg = READ_CSR_ME2FUNCTION_MAP_A(pmisc_addr, i);
		reg &= ~ME2FUNCTION_MAP_VALID;
		WRITE_CSR_ME2FUNCTION_MAP_A(pmisc_addr, i, reg);
	}

	/* Clear Valid bits in ME Thread to PCIe Function Mapping Group B */
	for (i = 0; i < ME2FUNCTION_MAP_B_NUM_REGS; i++) {
		reg = READ_CSR_ME2FUNCTION_MAP_B(pmisc_addr, i);
		reg &= ~ME2FUNCTION_MAP_VALID;
		WRITE_CSR_ME2FUNCTION_MAP_B(pmisc_addr, i, reg);
	}

	for (i = 0, vf = accel_dev->pf.vf_info; i < totalvfs; i++, vf++) {
		tasklet_disable(&vf->vf2pf_bh_tasklet);
		tasklet_kill(&vf->vf2pf_bh_tasklet);
		mutex_destroy(&vf->pf2vf_lock);
	}

	kfree(accel_dev->pf.vf_info);
	accel_dev->pf.vf_info = NULL;
}
EXPORT_SYMBOL_GPL(adf_disable_sriov);

/**
 * adf_sriov_configure() - Enable SRIOV for the device
 * @pdev:  Pointer to pci device.
 *
 * Function enables SRIOV for the pci device.
 *
 * Return: 0 on success, error code otherwise.
 */
int adf_sriov_configure(struct pci_dev *pdev, int numvfs)
{
	struct adf_accel_dev *accel_dev = adf_devmgr_pci_to_accel_dev(pdev);
	int totalvfs = pci_sriov_get_totalvfs(pdev);
	unsigned long val;
	int ret;

	if (!accel_dev) {
		dev_err(&pdev->dev, "Failed to find accel_dev\n");
		return -EFAULT;
	}

	if (!iommu_present(&pci_bus_type))
		dev_warn(&pdev->dev, "IOMMU should be enabled for SR-IOV to work correctly\n");

	if (accel_dev->pf.vf_info) {
		dev_info(&pdev->dev, "Already enabled for this device\n");
		return -EINVAL;
	}

	if (adf_dev_started(accel_dev)) {
		if (adf_devmgr_in_reset(accel_dev) ||
		    adf_dev_in_use(accel_dev)) {
			dev_err(&GET_DEV(accel_dev), "Device busy\n");
			return -EBUSY;
		}

		adf_dev_stop(accel_dev);
		adf_dev_shutdown(accel_dev);
	}

	if (adf_cfg_section_add(accel_dev, ADF_KERNEL_SEC))
		return -EFAULT;
	val = 0;
	if (adf_cfg_add_key_value_param(accel_dev, ADF_KERNEL_SEC,
					ADF_NUM_CY, (void *)&val, ADF_DEC))
		return -EFAULT;

	set_bit(ADF_STATUS_CONFIGURED, &accel_dev->status);

	/* Allocate memory for VF info structs */
	accel_dev->pf.vf_info = kcalloc(totalvfs,
					sizeof(struct adf_accel_vf_info),
					GFP_KERNEL);
	if (!accel_dev->pf.vf_info)
		return -ENOMEM;

	if (adf_dev_init(accel_dev)) {
		dev_err(&GET_DEV(accel_dev), "Failed to init qat_dev%d\n",
			accel_dev->accel_id);
		return -EFAULT;
	}

	if (adf_dev_start(accel_dev)) {
		dev_err(&GET_DEV(accel_dev), "Failed to start qat_dev%d\n",
			accel_dev->accel_id);
		return -EFAULT;
	}

	ret = adf_enable_sriov(accel_dev);
	if (ret)
		return ret;

	return numvfs;
}
EXPORT_SYMBOL_GPL(adf_sriov_configure);

int __init adf_init_pf_wq(void)
{
	/* Workqueue for PF2VF responses */
	pf2vf_resp_wq = alloc_workqueue("qat_pf2vf_resp_wq", WQ_MEM_RECLAIM, 0);

	return !pf2vf_resp_wq ? -ENOMEM : 0;
}

void adf_exit_pf_wq(void)
{
	if (pf2vf_resp_wq) {
		destroy_workqueue(pf2vf_resp_wq);
		pf2vf_resp_wq = NULL;
	}
}