/*-
* 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.
*
* $FreeBSD$
*/

/* Passthrough PCI device related operations */

#include <hypervisor.h>
#include <hv_lib.h>
#include <acrn_common.h>
#include <hv_arch.h>
#include <hv_debug.h>
#include "pci_priv.h"


static spinlock_t pci_device_lock = { .head = 0, .tail = 0 };


static uint32_t pci_pdev_calc_address(uint16_t bdf, uint32_t offset)
{
	uint32_t addr = bdf;

	addr <<= 8;
	addr |= (offset | PCI_CFG_ENABLE);

	return addr;
}

static uint32_t pci_pdev_read_cfg(struct pci_pdev *pdev,
	uint32_t offset, uint32_t bytes)
{
	uint32_t addr;
	uint32_t val;

	spinlock_obtain(&pci_device_lock);

	addr = pci_pdev_calc_address(pdev->bdf, offset);

	/* Write address to ADDRESS register */
	pio_write(addr, PCI_CONFIG_ADDR, 4);

	/* Read result from DATA register */
	switch (bytes) {
	case 1U:
		val = pio_read8(PCI_CONFIG_DATA + (offset & 3U));
		break;
	case 2U:
		val = pio_read16(PCI_CONFIG_DATA + (offset & 2U));
		break;
	default:
		val = pio_read32(PCI_CONFIG_DATA);
		break;
	}
	spinlock_release(&pci_device_lock);

	return val;
}

static void pci_pdev_write_cfg(struct pci_pdev *pdev, uint32_t offset,
	uint32_t bytes, uint32_t val)
{
	uint32_t addr;

	spinlock_obtain(&pci_device_lock);

	addr = pci_pdev_calc_address(pdev->bdf, offset);

	/* Write address to ADDRESS register */
	pio_write(addr, PCI_CONFIG_ADDR, 4);

	/* Write value to DATA register */
	switch (bytes) {
	case 1U:
		pio_write8(val, PCI_CONFIG_DATA + (offset & 3U));
		break;
	case 2U:
		pio_write16(val, PCI_CONFIG_DATA + (offset & 2U));
		break;
	default:
		pio_write32(val, PCI_CONFIG_DATA);
		break;
	}
	spinlock_release(&pci_device_lock);
}

static int vdev_pt_init_validate(struct pci_vdev *vdev)
{
	uint32_t idx;

	for (idx = 0; idx < (uint32_t)PCI_BAR_COUNT; idx++) {
		if (vdev->bar[idx].type != PCIM_BAR_MEM_32) {
			return -EINVAL;
		}
	}

	return 0;
}

static void vdev_pt_init_bar_registers(struct pci_vdev *vdev)
{
	uint32_t idx;

	for (idx = 0; idx < (uint32_t)PCI_BAR_COUNT; idx++) {
		/* Initialize the BAR register in config space */
		pci_vdev_write_cfg_u32(vdev, PCIR_BAR(idx),
			PCI_BAR(vdev->bar[idx].base, vdev->bar[idx].type));
	}
}

static int vdev_pt_init(struct pci_vdev *vdev)
{
	int ret;
	struct vm *vm = vdev->vpci->vm;

	ret = vdev_pt_init_validate(vdev);
	if (ret != 0) {
		pr_err("virtual bar can only be of type PCIM_BAR_MEM_32!");
		return ret;
	}

	/* Create an iommu domain for target VM if not created */
	if (vm->iommu == NULL) {
		if (vm->arch_vm.nworld_eptp == 0UL) {
			vm->arch_vm.nworld_eptp = alloc_paging_struct();
		}
		vm->iommu = create_iommu_domain(vm->vm_id,
			HVA2HPA(vm->arch_vm.nworld_eptp), 48U);
	}

	ret = assign_iommu_device(vm->iommu,
		PCI_BUS(vdev->pdev.bdf), LOBYTE(vdev->pdev.bdf));

	vdev_pt_init_bar_registers(vdev);

	return ret;
}

static int vdev_pt_deinit(struct pci_vdev *vdev)
{
	int ret;
	struct vm *vm = vdev->vpci->vm;

	ret = unassign_iommu_device(vm->iommu, PCI_BUS(vdev->pdev.bdf),
		LOBYTE(vdev->pdev.bdf));

	return ret;
}

static int bar_access(uint32_t coff)
{
	if ((coff >= PCIR_BAR(0U)) && (coff < PCIR_BAR(PCI_BAR_COUNT))) {
		return 1;
	} else {
		return 0;
	}
}

static int vdev_pt_cfgread(struct pci_vdev *vdev, uint32_t offset,
	uint32_t bytes, uint32_t *val)
{
	/* Assumption: access needed to be aligned on 1/2/4 bytes */
	if ((offset & (bytes - 1)) != 0U) {
		*val = 0xffffffffU;
		return -EINVAL;
	}

	/* PCI BARs is emulated */
	if (bar_access(offset)) {
		*val = pci_vdev_read_cfg(vdev, offset, bytes);
	} else {
		*val = pci_pdev_read_cfg(&vdev->pdev, offset, bytes);
	}

	return 0;
}

static int vdev_pt_remap_bar(struct pci_vdev *vdev, uint32_t idx,
	uint32_t new_base)
{
	int error = 0;
	struct vm *vm = vdev->vpci->vm;

	if (vdev->bar[idx].base != 0) {
		error = ept_mr_del(vm, (uint64_t *)vm->arch_vm.nworld_eptp,
			vdev->bar[idx].base,
			vdev->bar[idx].size);
		if (error) {
			return error;
		}
	}

	if (new_base != 0U) {
		/* Map the physical BAR in the guest MMIO space */
		error = ept_mr_add(vm,
			vdev->pdev.bar[idx].base, /* HPA */
			new_base, /*GPA*/
			vdev->bar[idx].size,
			EPT_WR | EPT_RD | EPT_UNCACHED);
		if (error) {
			return error;
		}
	}
	return error;
}

static uint32_t memen(struct pci_vdev *vdev)
{
	return pci_pdev_read_cfg(&vdev->pdev, PCIR_COMMAND, 2)
		& PCIM_CMD_MEMEN;
}

static void vdev_pt_cfgwrite_bar(struct pci_vdev *vdev, uint32_t offset,
	uint32_t bytes, uint32_t new_bar_uos)
{
	uint32_t idx;
	uint32_t new_bar, mask;
	bool bar_update_normal = 1;
	bool do_map;
	int error;

	idx = (offset - PCIR_BAR(0U)) >> 2U;
	mask = ~(vdev->bar[idx].size - 1U);
	bar_update_normal = (new_bar_uos != (uint32_t)~0U);
	new_bar = new_bar_uos & mask;
	new_bar |= PCIM_BAR_MEM_SPACE | PCIM_BAR_MEM_32;

	if (PCI_BAR_BASE(new_bar) == vdev->bar[idx].base) {
		return;
	}

	do_map = (memen(vdev)) && bar_update_normal;
	if (do_map) {
		error = vdev_pt_remap_bar(vdev, idx, PCI_BAR_BASE(new_bar));
		if (error) {
			pr_err("vdev_pt_remap_bar failed: %d", idx);
		}
	}

	pci_vdev_write_cfg_u32(vdev, offset, new_bar);
	vdev->bar[idx].base = PCI_BAR_BASE(new_bar);
}

static int vdev_pt_cfgwrite(struct pci_vdev *vdev, uint32_t offset,
	uint32_t bytes, uint32_t val)
{
	/* Assumption: access needed to be aligned on 1/2/4 bytes */
	if ((offset & (bytes - 1)) != 0U) {
		return -EINVAL;
	}

	/* PCI BARs are emulated */
	if (bar_access(offset)) {
		vdev_pt_cfgwrite_bar(vdev, offset, bytes, val);
	} else {
		/* Write directly to physical device's config space */
		pci_pdev_write_cfg(&vdev->pdev, offset, bytes, val);
	}

	return 0;
}

struct pci_vdev_ops pci_ops_vdev_pt = {
	.init = vdev_pt_init,
	.deinit = vdev_pt_deinit,
	.cfgwrite = vdev_pt_cfgwrite,
	.cfgread = vdev_pt_cfgread,
};