/*
 * Copyright (c) 2011 NetApp, Inc.
 * Copyright (c) 2018 Intel Corporation
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``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 NETAPP, INC 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.
 *
 * $FreeBSD$
 */

#include <vm.h>
#include <errno.h>
#include <ptdev.h>
#include <assign.h>
#include <vpci.h>
#include "vpci_priv.h"


/**
 * @pre vdev != NULL
 */
static inline bool has_msi_cap(const struct pci_vdev *vdev)
{
	return (vdev->msi.capoff != 0U);
}

/**
 * @pre vdev != NULL
 */
static inline bool msicap_access(const struct pci_vdev *vdev, uint32_t offset)
{
	bool ret = false;

	if (has_msi_cap(vdev)) {
		ret = in_range(offset, vdev->msi.capoff, vdev->msi.caplen);
	}

	return ret;
}

/**
 * @pre vdev != NULL
 * @pre vdev->vpci != NULL
 * @pre vdev->vpci->vm != NULL
 * @pre vdev->pdev != NULL
 */
static int32_t vmsi_remap(const struct pci_vdev *vdev, bool enable)
{
	struct ptirq_msi_info info;
	union pci_bdf pbdf = vdev->pdev->bdf;
	struct acrn_vm *vm = vdev->vpci->vm;
	uint32_t capoff = vdev->msi.capoff;
	uint32_t msgctrl, msgdata;
	uint32_t addrlo, addrhi;
	int32_t ret;

	/* Disable MSI during configuration */
	msgctrl = pci_vdev_read_cfg(vdev, capoff + PCIR_MSI_CTRL, 2U);
	if ((msgctrl & PCIM_MSICTRL_MSI_ENABLE) == PCIM_MSICTRL_MSI_ENABLE) {
		pci_pdev_write_cfg(pbdf, capoff + PCIR_MSI_CTRL, 2U, msgctrl & ~PCIM_MSICTRL_MSI_ENABLE);
	}

	/* Read the MSI capability structure from virtual device */
	addrlo = pci_vdev_read_cfg_u32(vdev, capoff + PCIR_MSI_ADDR);
	if ((msgctrl & PCIM_MSICTRL_64BIT) != 0U) {
		msgdata = pci_vdev_read_cfg_u16(vdev, capoff + PCIR_MSI_DATA_64BIT);
		addrhi = pci_vdev_read_cfg_u32(vdev, capoff + PCIR_MSI_ADDR_HIGH);
	} else {
		msgdata = pci_vdev_read_cfg_u16(vdev, capoff + PCIR_MSI_DATA);
		addrhi = 0U;
	}

	info.vmsi_addr.full = (uint64_t)addrlo | ((uint64_t)addrhi << 32U);

	/* MSI is being enabled or disabled */
	if (enable) {
		info.vmsi_data.full = msgdata;
	} else {
		info.vmsi_data.full = 0U;
	}

	ret = ptirq_msix_remap(vm, vdev->vbdf.value, pbdf.value, 0U, &info);
	if (ret == 0) {
		/* Update MSI Capability structure to physical device */
		pci_pdev_write_cfg(pbdf, capoff + PCIR_MSI_ADDR, 0x4U, (uint32_t)info.pmsi_addr.full);
		if ((msgctrl & PCIM_MSICTRL_64BIT) != 0U) {
			pci_pdev_write_cfg(pbdf, capoff + PCIR_MSI_ADDR_HIGH, 0x4U,
				(uint32_t)(info.pmsi_addr.full >> 32U));
			pci_pdev_write_cfg(pbdf, capoff + PCIR_MSI_DATA_64BIT, 0x2U, (uint16_t)info.pmsi_data.full);
		} else {
			pci_pdev_write_cfg(pbdf, capoff + PCIR_MSI_DATA, 0x2U, (uint16_t)info.pmsi_data.full);
		}

		/* If MSI Enable is being set, make sure INTxDIS bit is set */
		if (enable) {
			enable_disable_pci_intx(pbdf, false);
			pci_pdev_write_cfg(pbdf, capoff + PCIR_MSI_CTRL, 2U, msgctrl | PCIM_MSICTRL_MSI_ENABLE);
		}
	}

	return ret;
}

/**
 * @pre vdev != NULL
 */
int32_t vmsi_read_cfg(const struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t *val)
{
	int32_t ret = -ENODEV;

	/* For PIO access, we emulate Capability Structures only */
	if (msicap_access(vdev, offset)) {
		*val = pci_vdev_read_cfg(vdev, offset, bytes);
	    ret = 0;
	}

	return ret;
}

/**
 * @pre vdev != NULL
 */
int32_t vmsi_write_cfg(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t val)
{
	bool message_changed = false;
	bool enable;
	uint32_t msgctrl;
	int32_t ret = -ENODEV;

	/* Writing MSI Capability Structure */
	if (msicap_access(vdev, offset)) {

		/* Save msgctrl for comparison */
		msgctrl = pci_vdev_read_cfg(vdev, vdev->msi.capoff + PCIR_MSI_CTRL, 2U);

		/* Either Message Data or message Addr is being changed */
		if (((offset - vdev->msi.capoff) >= PCIR_MSI_ADDR) && (val != pci_vdev_read_cfg(vdev, offset, bytes))) {
			message_changed = true;
		}

		/* Write to vdev */
		pci_vdev_write_cfg(vdev, offset, bytes, val);

		/* Do remap if MSI Enable bit is being changed */
		if (((offset - vdev->msi.capoff) == PCIR_MSI_CTRL) &&
			(((msgctrl ^ val) & PCIM_MSICTRL_MSI_ENABLE) != 0U)) {
			enable = ((val & PCIM_MSICTRL_MSI_ENABLE) != 0U);
			(void)vmsi_remap(vdev, enable);
		} else {
			if (message_changed && ((msgctrl & PCIM_MSICTRL_MSI_ENABLE) != 0U)) {
				(void)vmsi_remap(vdev, true);
			}
		}

		ret = 0;
	}

	return ret;
}

/**
 * @pre vdev != NULL
 * @pre vdev->vpci != NULL
 * @pre vdev->vpci->vm != NULL
 */
void deinit_vmsi(const struct pci_vdev *vdev)
{
	if (has_msi_cap(vdev)) {
		ptirq_remove_msix_remapping(vdev->vpci->vm, vdev->vbdf.value, 1U);
	}
}

/* Read a uint32_t from buffer (little endian) */
static uint32_t buf_read32(const uint8_t buf[])
{
	return buf[0] | ((uint32_t)buf[1] << 8U) | ((uint32_t)buf[2] << 16U) | ((uint32_t)buf[3] << 24U);
}

/* Write a uint32_t to buffer (little endian) */
static void buf_write32(uint8_t buf[], uint32_t val)
{
	buf[0] = (uint8_t)(val & 0xFFU);
	buf[1] = (uint8_t)((val >> 8U)  & 0xFFU);
	buf[2] = (uint8_t)((val >> 16U) & 0xFFU);
	buf[3] = (uint8_t)((val >> 24U) & 0xFFU);
}

/**
 * @pre vdev != NULL
 * @pre vdev->pdev != NULL
 */
void init_vmsi(struct pci_vdev *vdev)
{
	struct pci_pdev *pdev = vdev->pdev;
	uint32_t val;

	vdev->msi.capoff = pdev->msi.capoff;
	vdev->msi.caplen = pdev->msi.caplen;

	if (has_msi_cap(vdev)) {
		(void)memcpy_s((void *)&vdev->cfgdata.data_8[pdev->msi.capoff], pdev->msi.caplen,
			(void *)&pdev->msi.cap[0U], pdev->msi.caplen);

		val = buf_read32(&pdev->msi.cap[0U]);
		val &= ~((uint32_t)PCIM_MSICTRL_MMC_MASK << 16U);
		val &= ~((uint32_t)PCIM_MSICTRL_MME_MASK << 16U);

		buf_write32(&vdev->cfgdata.data_8[pdev->msi.capoff], val);
	}
}