/*-
* 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 <ept.h>
#include <mmu.h>
#include <logmsg.h>
#include "vpci_priv.h"

/**
 * @brief get bar's full base address in 64-bit
 * @pre idx < nr_bars
 * For 64-bit MMIO bar, its lower 32-bits base address and upper 32-bits base are combined
 * into one 64-bit base address
 */
static uint64_t pci_bar_2_bar_base(const struct pci_bar *pbars, uint32_t nr_bars, uint32_t idx)
{
	uint64_t base = 0UL;
	uint64_t tmp;
	const struct pci_bar *bar;

	bar = &pbars[idx];

	if (bar->is_64bit_high) {
		ASSERT(idx > 0U, "idx for upper 32-bit of the 64-bit bar should be greater than 0!");
		if (idx > 0U) {
			const struct pci_bar *prev_bar = &pbars[idx - 1U];

			/* Upper 32-bit of 64-bit bar (does not have flags portion) */
			base = (uint64_t)(bar->reg.value);
			base <<= 32U;

			/* Lower 32-bit of a 64-bit bar (BITS 31-4 = base address, 16-byte aligned) */
			tmp = (uint64_t)(prev_bar->reg.bits.mem.base);
			tmp <<= 4U;

			base |= tmp;
		}
	} else {
		enum pci_bar_type type = pci_get_bar_type(bar->reg.value);

		switch (type) {
		case PCIBAR_IO_SPACE:
			/* IO bar, BITS 31-2 = base address, 4-byte aligned */
			base = (uint64_t)(bar->reg.bits.io.base);
			base <<= 2U;
			break;

		case PCIBAR_MEM32:
			base = (uint64_t)(bar->reg.bits.mem.base);
			base <<= 4U;
			break;

		case PCIBAR_MEM64:
			ASSERT((idx + 1U) < nr_bars, "idx for upper 32-bit of the 64-bit bar is out of range!");
			if ((idx + 1U) < nr_bars) {
				const struct pci_bar *next_bar = &pbars[idx + 1U];

				/* Upper 32-bit of 64-bit bar */
				base = (uint64_t)(next_bar->reg.value);
				base <<= 32U;

				/* Lower 32-bit of a 64-bit bar (BITS 31-4 = base address, 16-byte aligned) */
				tmp = (uint64_t)(bar->reg.bits.mem.base);
				tmp <<= 4U;

				base |= tmp;
			}
			break;

		default:
			/* Nothing to do */
			break;
		}
	}

	return base;
}

/**
 * @brief get vbar's full base address in 64-bit
 * For 64-bit MMIO bar, its lower 32-bits base address and upper 32-bits base are combined
 * into one 64-bit base address
 * @pre vdev != NULL
 */
static uint64_t get_vbar_base(const struct pci_vdev *vdev, uint32_t idx)
{
	return pci_bar_2_bar_base(&vdev->bar[0], vdev->nr_bars, idx);
}

/**
 * @brief get pbar's full address in 64-bit
 * For 64-bit MMIO bar, its lower 32-bits base address and upper 32-bits base are combined
 * into one 64-bit base address
 * @pre pdev != NULL
 */
static uint64_t get_pbar_base(const struct pci_pdev *pdev, uint32_t idx)
{
	return pci_bar_2_bar_base(&pdev->bar[0], pdev->nr_bars, idx);
}

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

	if (is_prelaunched_vm(vdev->vpci->vm) && is_bar_offset(vdev->nr_bars, offset)) {
		*val = pci_vdev_read_cfg(vdev, offset, bytes);
		ret = 0;
	}

	return ret;
}

/**
* @pre vdev != NULL
* @pre vdev->vpci != NULL
* @pre vdev->vpci->vm != NULL
* @pre vdev->pdev != NULL
* @pre vdev->pdev->msix.table_bar < vdev->nr_bars
*/
void vdev_pt_remap_msix_table_bar(struct pci_vdev *vdev)
{
	uint32_t i;
	uint64_t addr_hi, addr_lo;
	struct pci_msix *msix = &vdev->msix;
	struct pci_pdev *pdev = vdev->pdev;
	struct pci_bar *pbar;

	ASSERT(vdev->pdev->msix.table_bar < vdev->nr_bars, "msix->table_bar is out of range");

	/* Mask all table entries */
	for (i = 0U; i < msix->table_count; i++) {
		msix->table_entries[i].vector_control = PCIM_MSIX_VCTRL_MASK;
		msix->table_entries[i].addr = 0U;
		msix->table_entries[i].data = 0U;
	}

	pbar = &pdev->bar[msix->table_bar];
	if (pbar != NULL) {
		uint64_t pbar_base = get_pbar_base(pdev, msix->table_bar); /* pbar (hpa) */

		msix->mmio_hpa = pbar_base;
		if (is_prelaunched_vm(vdev->vpci->vm)) {
			msix->mmio_gpa = get_vbar_base(vdev, msix->table_bar);
		} else {
			msix->mmio_gpa = sos_vm_hpa2gpa(pbar_base);
		}
		msix->mmio_size = pbar->size;
	}

	/*
	 *    For SOS:
	 *    --------
	 *    MSI-X Table BAR Contains:
	 *    Other Info + Tables + PBA	        Other info already mapped into EPT (since SOS)
	 *    					Tables are handled by HV MMIO handler (4k adjusted up and down)
	 *    						and remaps interrupts
	 *    					PBA already mapped into EPT (since SOS)
	 *
	 *    Other Info + Tables		Other info already mapped into EPT (since SOS)
	 *					Tables are handled by HV MMIO handler (4k adjusted up and down)
	 *						and remaps interrupts
	 *
	 *    Tables				Tables are handled by HV MMIO handler (4k adjusted up and down)
	 *    						and remaps interrupts
	 *
	 *    For UOS (launched by DM):
	 *    -------------------------
	 *    MSI-X Table BAR Contains:
	 *    Other Info + Tables + PBA		Other info  mapped into EPT (4k adjusted) by DM
	 *    					Tables are handled by DM MMIO handler (4k adjusted up and down) and SOS writes to tables,
	 *    						intercepted by HV MMIO handler and HV remaps interrupts
	 *    					PBA already mapped into EPT by DM
	 *
	 *    Other Info + Tables		Other info mapped into EPT by DM
	 *    					Tables are handled by DM MMIO handler (4k adjusted up and down) and SOS writes to tables,
	 *    						intercepted by HV MMIO handler and HV remaps interrupts.
	 *
	 *    Tables				Tables are handled by DM MMIO handler (4k adjusted up and down) and SOS writes to tables,
	 *    						intercepted by HV MMIO handler and HV remaps interrupts.
	 *
	 *    For Pre-launched VMs (no SOS/DM):
	 *    --------------------------------
	 *    MSI-X Table BAR Contains:
	 *    All 3 cases:			Writes to MMIO region in MSI-X Table BAR handled by HV MMIO handler
	 *    					If the offset falls within the MSI-X table [offset, offset+tables_size), HV remaps
	 *    						interrupts.
	 *    					Else, HV writes/reads to/from the corresponding HPA
	 */


	if (msix->mmio_gpa != 0UL) {
		if (is_prelaunched_vm(vdev->vpci->vm)) {
			addr_hi = msix->mmio_gpa + msix->mmio_size;
			addr_lo = msix->mmio_gpa;
		} else {
			/*
			* PCI Spec: a BAR may also map other usable address space that is not associated
			* with MSI-X structures, but it must not share any naturally aligned 4 KB
			* address range with one where either MSI-X structure resides.
			* The MSI-X Table and MSI-X PBA are permitted to co-reside within a naturally
			* aligned 4 KB address range.
			*
			* If PBA or others reside in the same BAR with MSI-X Table, devicemodel could
			* emulate them and maps these memory range at the 4KB boundary. Here, we should
			* make sure only intercept the minimum number of 4K pages needed for MSI-X table.
			*/

			/* The higher boundary of the 4KB aligned address range for MSI-X table */
			addr_hi = msix->mmio_gpa + msix->table_offset + (msix->table_count * MSIX_TABLE_ENTRY_SIZE);
			addr_hi = round_page_up(addr_hi);

			/* The lower boundary of the 4KB aligned address range for MSI-X table */
			addr_lo = round_page_down(msix->mmio_gpa + msix->table_offset);
		}

		if (vdev->bar_base_mapped[msix->table_bar] != addr_lo) {
			register_mmio_emulation_handler(vdev->vpci->vm, vmsix_table_mmio_access_handler,
				addr_lo, addr_hi, vdev);
			/* Remember the previously registered MMIO vbar base */
			vdev->bar_base_mapped[msix->table_bar] = addr_lo;
		}
	}
}

/**
 * @brief Remaps guest MMIO BARs other than MSI-x Table BAR
 * This API is invoked upon guest re-programming PCI BAR with MMIO region
 * after a new vbar is set.
 * @pre vdev != NULL
 * @pre vdev->vpci != NULL
 * @pre vdev->vpci->vm != NULL
 */
static void vdev_pt_remap_generic_mem_vbar(struct pci_vdev *vdev, uint32_t idx)
{
	struct acrn_vm *vm = vdev->vpci->vm;
	uint64_t vbar_base = get_vbar_base(vdev, idx); /* vbar (gpa) */

	/* If the old vbar is mapped before, unmap it first */
	if (vdev->bar_base_mapped[idx] != 0UL) {
		ept_del_mr(vm, (uint64_t *)(vm->arch_vm.nworld_eptp),
			vdev->bar_base_mapped[idx], /* GPA (old vbar) */
			vdev->bar[idx].size);
		vdev->bar_base_mapped[idx] = 0UL;
	}

	/* If a new vbar is set (nonzero), set the EPT mapping accordingly */
	if (vbar_base != 0UL) {
		uint64_t pbar_base = get_pbar_base(vdev->pdev, idx); /* pbar (hpa) */

		/* Map the physical BAR in the guest MMIO space */
		ept_add_mr(vm, (uint64_t *)(vm->arch_vm.nworld_eptp),
			pbar_base, /* HPA (pbar) */
			vbar_base, /* GPA (new vbar) */
			vdev->bar[idx].size,
			EPT_WR | EPT_RD | EPT_UNCACHED);

		/* Remember the previously mapped MMIO vbar */
		vdev->bar_base_mapped[idx] = vbar_base;
	}
}

/**
 * @brief Set the base address portion of the vbar base address register (32-bit)
 * base: bar value with flags portion masked off
 * @pre vbar != NULL
 */
static void set_vbar_base(struct pci_bar *vbar, uint32_t base)
{
	union pci_bar_reg bar_reg;

	bar_reg.value = base;

	if (vbar->is_64bit_high) {
		/* Upper 32-bit of a 64-bit bar does not have the flags portion */
		vbar->reg.value = bar_reg.value;
	} else if (vbar->reg.bits.io.is_io == 1U) {
		/* IO bar, BITS 31-2 = base address, 4-byte aligned */
		vbar->reg.bits.io.base = bar_reg.bits.io.base;
	} else {
		/* MMIO bar, BITS 31-4 = base address, 16-byte aligned */
		vbar->reg.bits.mem.base = bar_reg.bits.mem.base;
	}
}

/**
 * @pre vdev != NULL
 * @pre (vdev->bar[idx].type == PCIBAR_NONE) || (vdev->bar[idx].type == PCIBAR_MEM32)
 */
static void vdev_pt_write_vbar(struct pci_vdev *vdev, uint32_t offset, uint32_t val)
{
	uint32_t idx;
	uint32_t base, mask;
	bool bar_update_normal;
	bool is_msix_table_bar;

	base = 0U;
	idx = (offset - pci_bar_offset(0U)) >> 2U;
	mask = ~(vdev->bar[idx].size - 1U);

	switch (vdev->bar[idx].type) {
	case PCIBAR_NONE:
		vdev->bar[idx].base = 0UL;
		break;

	case PCIBAR_MEM32:
		bar_update_normal = (val != (uint32_t)~0U);
		is_msix_table_bar = (has_msix_cap(vdev) && (idx == vdev->msix.table_bar));
		base = val & mask;
		set_vbar_base(&vdev->bar[idx], base);

		if (bar_update_normal) {
			if (is_msix_table_bar) {
				vdev->bar[idx].base = base;
				vdev_pt_remap_msix_table_bar(vdev);
			} else {
				vdev_pt_remap_generic_mem_vbar(vdev, idx);
				vdev->bar[idx].base = base;
			}
		}
		break;

	default:
		/* Should never reach here, init_vdev_pt() only sets vbar type to PCIBAR_NONE and PCIBAR_MEM32 */
		break;
	}

	/* Write the vbar value to corresponding virtualized vbar reg */
	pci_vdev_write_cfg_u32(vdev, offset, vdev->bar[idx].reg.value);
}

/**
 * @pre vdev != NULL
 * @pre vdev->vpci != NULL
 * @pre vdev->vpci->vm != NULL
 * bar write access must be 4 bytes and offset must also be 4 bytes aligned, it will be dropped otherwise
 */
int32_t vdev_pt_write_cfg(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t val)
{
	int32_t ret = -ENODEV;

	/* bar write access must be 4 bytes and offset must also be 4 bytes aligned */
	if (is_prelaunched_vm(vdev->vpci->vm) && is_bar_offset(vdev->nr_bars, offset)
		&& (bytes == 4U) && ((offset & 0x3U) == 0U)) {
		vdev_pt_write_vbar(vdev, offset, val);
		ret = 0;
	}

	return ret;
}

/**
 * For bar emulation, currently only MMIO is supported and bar size cannot be greater than 4GB
 * @pre bar != NULL
 */
static inline bool is_bar_supported(const struct pci_bar *bar)
{
	return (is_mmio_bar(bar) && is_valid_bar_size(bar));
}

/**
 * PCI base address register (bar) virtualization:
 *
 * Virtualize the PCI bars (up to 6 bars at byte offset 0x10~0x24 for type 0 PCI device,
 * 2 bars at byte offset 0x10-0x14 for type 1 PCI device) of the PCI configuration space
 * header.
 *
 * pbar: bar for the physical PCI device (pci_pdev), the value of pbar (hpa) is assigned
 * by platform firmware during boot. It is assumed a valid hpa is always assigned to a
 * mmio pbar, hypervisor shall not change the value of a pbar.
 *
 * vbar: for each pci_pdev, it has a virtual PCI device (pci_vdev) counterpart. pci_vdev
 * virtualizes all the bars (called vbars). a vbar can be initialized by hypervisor by
 * assigning a gpa to it; if vbar has a value of 0 (unassigned), guest may assign
 * and program a gpa to it. The guest only sees the vbars, it will not see and can
 * never change the pbars.
 *
 * Hypervisor traps guest changes to the mmio vbar (gpa) to establish ept mapping
 * between vbar(gpa) and pbar(hpa). pbar should always align on 4K boundary.
 *
 * @pre vdev != NULL
 * @pre vdev->vpci != NULL
 * @pre vdev->vpci->vm != NULL
 * @pre vdev->pdev != NULL
 */
void init_vdev_pt(struct pci_vdev *vdev)
{
	uint32_t idx;
	struct pci_bar *pbar, *vbar;
	uint16_t pci_command;

	vdev->nr_bars = vdev->pdev->nr_bars;

	ASSERT(vdev->nr_bars > 0U, "vdev->nr_bars should be greater than 0!");

	if (is_prelaunched_vm(vdev->vpci->vm)) {
		for (idx = 0U; idx < vdev->nr_bars; idx++) {
			pbar = &vdev->pdev->bar[idx];
			vbar = &vdev->bar[idx];

			vbar->base = 0UL;
			if (is_bar_supported(pbar)) {
				vbar->reg.value = pbar->reg.value;
				vbar->reg.bits.mem.base = 0x0U; /* clear vbar base */
				if (vbar->reg.bits.mem.type == 0x2U) {
					/* Clear vbar 64-bit flag and set it to 32-bit */
					vbar->reg.bits.mem.type = 0x0U;
				}

				/**
				 * If vbar->base is 0 (unassigned), Linux kernel will reprogram the vbar on
				 * its bar size boundary, so in order to ensure the MMIO vbar allocated by guest
				 * is 4k aligned, set its size to be 4K aligned.
				 */
				vbar->size = round_page_up(pbar->size);

				/**
				 * Only 32-bit bar is supported for now so both PCIBAR_MEM32 and PCIBAR_MEM64
				 * are reported to guest as PCIBAR_MEM32
				 */
				vbar->type = PCIBAR_MEM32;

				/* Set the new vbar base */
				if (vdev->ptdev_config->vbar[idx] != 0UL) {
					vdev_pt_write_vbar(vdev, pci_bar_offset(idx), (uint32_t)(vdev->ptdev_config->vbar[idx]));
				}
			} else {
				vbar->reg.value = 0x0U;
				vbar->size = 0UL;
				vbar->type = PCIBAR_NONE;
			}
		}

		pci_command = (uint16_t)pci_pdev_read_cfg(vdev->pdev->bdf, PCIR_COMMAND, 2U);
		/* Disable INTX */
		pci_command |= 0x400U;
		pci_pdev_write_cfg(vdev->pdev->bdf, PCIR_COMMAND, 2U, pci_command);
	}
}