/*
 * Copyright 2008 Advanced Micro Devices, Inc.
 * Copyright 2008 Red Hat Inc.
 * Copyright 2009 Jerome Glisse.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: Dave Airlie
 *          Alex Deucher
 *          Jerome Glisse
 */
#include <drm/drmP.h>
#include "amdgpu.h"
#include "atom.h"

#include <linux/vga_switcheroo.h>
#include <linux/slab.h>
#include <linux/acpi.h>
/*
 * BIOS.
 */

/* If you boot an IGP board with a discrete card as the primary,
 * the IGP rom is not accessible via the rom bar as the IGP rom is
 * part of the system bios.  On boot, the system bios puts a
 * copy of the igp rom at the start of vram if a discrete card is
 * present.
 */
static bool igp_read_bios_from_vram(struct amdgpu_device *adev)
{
	uint8_t __iomem *bios;
	resource_size_t vram_base;
	resource_size_t size = 256 * 1024; /* ??? */

	if (!(adev->flags & AMD_IS_APU))
		if (!amdgpu_card_posted(adev))
			return false;

	adev->bios = NULL;
	vram_base = pci_resource_start(adev->pdev, 0);
	bios = ioremap(vram_base, size);
	if (!bios) {
		return false;
	}

	if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) {
		iounmap(bios);
		return false;
	}
	adev->bios = kmalloc(size, GFP_KERNEL);
	if (adev->bios == NULL) {
		iounmap(bios);
		return false;
	}
	memcpy_fromio(adev->bios, bios, size);
	iounmap(bios);
	return true;
}

bool amdgpu_read_bios(struct amdgpu_device *adev)
{
	uint8_t __iomem *bios, val1, val2;
	size_t size;

	adev->bios = NULL;
	/* XXX: some cards may return 0 for rom size? ddx has a workaround */
	bios = pci_map_rom(adev->pdev, &size);
	if (!bios) {
		return false;
	}

	val1 = readb(&bios[0]);
	val2 = readb(&bios[1]);

	if (size == 0 || val1 != 0x55 || val2 != 0xaa) {
		pci_unmap_rom(adev->pdev, bios);
		return false;
	}
	adev->bios = kzalloc(size, GFP_KERNEL);
	if (adev->bios == NULL) {
		pci_unmap_rom(adev->pdev, bios);
		return false;
	}
	memcpy_fromio(adev->bios, bios, size);
	pci_unmap_rom(adev->pdev, bios);
	return true;
}

static bool amdgpu_read_platform_bios(struct amdgpu_device *adev)
{
	uint8_t __iomem *bios;
	size_t size;

	adev->bios = NULL;

	bios = pci_platform_rom(adev->pdev, &size);
	if (!bios) {
		return false;
	}

	if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) {
		return false;
	}
	adev->bios = kmemdup(bios, size, GFP_KERNEL);
	if (adev->bios == NULL) {
		return false;
	}

	return true;
}

#ifdef CONFIG_ACPI
/* ATRM is used to get the BIOS on the discrete cards in
 * dual-gpu systems.
 */
/* retrieve the ROM in 4k blocks */
#define ATRM_BIOS_PAGE 4096
/**
 * amdgpu_atrm_call - fetch a chunk of the vbios
 *
 * @atrm_handle: acpi ATRM handle
 * @bios: vbios image pointer
 * @offset: offset of vbios image data to fetch
 * @len: length of vbios image data to fetch
 *
 * Executes ATRM to fetch a chunk of the discrete
 * vbios image on PX systems (all asics).
 * Returns the length of the buffer fetched.
 */
static int amdgpu_atrm_call(acpi_handle atrm_handle, uint8_t *bios,
			    int offset, int len)
{
	acpi_status status;
	union acpi_object atrm_arg_elements[2], *obj;
	struct acpi_object_list atrm_arg;
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};

	atrm_arg.count = 2;
	atrm_arg.pointer = &atrm_arg_elements[0];

	atrm_arg_elements[0].type = ACPI_TYPE_INTEGER;
	atrm_arg_elements[0].integer.value = offset;

	atrm_arg_elements[1].type = ACPI_TYPE_INTEGER;
	atrm_arg_elements[1].integer.value = len;

	status = acpi_evaluate_object(atrm_handle, NULL, &atrm_arg, &buffer);
	if (ACPI_FAILURE(status)) {
		printk("failed to evaluate ATRM got %s\n", acpi_format_exception(status));
		return -ENODEV;
	}

	obj = (union acpi_object *)buffer.pointer;
	memcpy(bios+offset, obj->buffer.pointer, obj->buffer.length);
	len = obj->buffer.length;
	kfree(buffer.pointer);
	return len;
}

static bool amdgpu_atrm_get_bios(struct amdgpu_device *adev)
{
	int ret;
	int size = 256 * 1024;
	int i;
	struct pci_dev *pdev = NULL;
	acpi_handle dhandle, atrm_handle;
	acpi_status status;
	bool found = false;

	/* ATRM is for the discrete card only */
	if (adev->flags & AMD_IS_APU)
		return false;

	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
		dhandle = ACPI_HANDLE(&pdev->dev);
		if (!dhandle)
			continue;

		status = acpi_get_handle(dhandle, "ATRM", &atrm_handle);
		if (!ACPI_FAILURE(status)) {
			found = true;
			break;
		}
	}

	if (!found) {
		while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) != NULL) {
			dhandle = ACPI_HANDLE(&pdev->dev);
			if (!dhandle)
				continue;

			status = acpi_get_handle(dhandle, "ATRM", &atrm_handle);
			if (!ACPI_FAILURE(status)) {
				found = true;
				break;
			}
		}
	}

	if (!found)
		return false;

	adev->bios = kmalloc(size, GFP_KERNEL);
	if (!adev->bios) {
		DRM_ERROR("Unable to allocate bios\n");
		return false;
	}

	for (i = 0; i < size / ATRM_BIOS_PAGE; i++) {
		ret = amdgpu_atrm_call(atrm_handle,
				       adev->bios,
				       (i * ATRM_BIOS_PAGE),
				       ATRM_BIOS_PAGE);
		if (ret < ATRM_BIOS_PAGE)
			break;
	}

	if (i == 0 || adev->bios[0] != 0x55 || adev->bios[1] != 0xaa) {
		kfree(adev->bios);
		return false;
	}
	return true;
}
#else
static inline bool amdgpu_atrm_get_bios(struct amdgpu_device *adev)
{
	return false;
}
#endif

static bool amdgpu_read_disabled_bios(struct amdgpu_device *adev)
{
	if (adev->flags & AMD_IS_APU)
		return igp_read_bios_from_vram(adev);
	else
		return amdgpu_asic_read_disabled_bios(adev);
}

#ifdef CONFIG_ACPI
static bool amdgpu_acpi_vfct_bios(struct amdgpu_device *adev)
{
	bool ret = false;
	struct acpi_table_header *hdr;
	acpi_size tbl_size;
	UEFI_ACPI_VFCT *vfct;
	GOP_VBIOS_CONTENT *vbios;
	VFCT_IMAGE_HEADER *vhdr;

	if (!ACPI_SUCCESS(acpi_get_table_with_size("VFCT", 1, &hdr, &tbl_size)))
		return false;
	if (tbl_size < sizeof(UEFI_ACPI_VFCT)) {
		DRM_ERROR("ACPI VFCT table present but broken (too short #1)\n");
		goto out_unmap;
	}

	vfct = (UEFI_ACPI_VFCT *)hdr;
	if (vfct->VBIOSImageOffset + sizeof(VFCT_IMAGE_HEADER) > tbl_size) {
		DRM_ERROR("ACPI VFCT table present but broken (too short #2)\n");
		goto out_unmap;
	}

	vbios = (GOP_VBIOS_CONTENT *)((char *)hdr + vfct->VBIOSImageOffset);
	vhdr = &vbios->VbiosHeader;
	DRM_INFO("ACPI VFCT contains a BIOS for %02x:%02x.%d %04x:%04x, size %d\n",
			vhdr->PCIBus, vhdr->PCIDevice, vhdr->PCIFunction,
			vhdr->VendorID, vhdr->DeviceID, vhdr->ImageLength);

	if (vhdr->PCIBus != adev->pdev->bus->number ||
	    vhdr->PCIDevice != PCI_SLOT(adev->pdev->devfn) ||
	    vhdr->PCIFunction != PCI_FUNC(adev->pdev->devfn) ||
	    vhdr->VendorID != adev->pdev->vendor ||
	    vhdr->DeviceID != adev->pdev->device) {
		DRM_INFO("ACPI VFCT table is not for this card\n");
		goto out_unmap;
	}

	if (vfct->VBIOSImageOffset + sizeof(VFCT_IMAGE_HEADER) + vhdr->ImageLength > tbl_size) {
		DRM_ERROR("ACPI VFCT image truncated\n");
		goto out_unmap;
	}

	adev->bios = kmemdup(&vbios->VbiosContent, vhdr->ImageLength, GFP_KERNEL);
	ret = !!adev->bios;

out_unmap:
	return ret;
}
#else
static inline bool amdgpu_acpi_vfct_bios(struct amdgpu_device *adev)
{
	return false;
}
#endif

bool amdgpu_get_bios(struct amdgpu_device *adev)
{
	bool r;
	uint16_t tmp;

	r = amdgpu_atrm_get_bios(adev);
	if (r == false)
		r = amdgpu_acpi_vfct_bios(adev);
	if (r == false)
		r = igp_read_bios_from_vram(adev);
	if (r == false)
		r = amdgpu_read_bios(adev);
	if (r == false) {
		r = amdgpu_read_disabled_bios(adev);
	}
	if (r == false) {
		r = amdgpu_read_platform_bios(adev);
	}
	if (r == false || adev->bios == NULL) {
		DRM_ERROR("Unable to locate a BIOS ROM\n");
		adev->bios = NULL;
		return false;
	}
	if (adev->bios[0] != 0x55 || adev->bios[1] != 0xaa) {
		printk("BIOS signature incorrect %x %x\n", adev->bios[0], adev->bios[1]);
		goto free_bios;
	}

	tmp = RBIOS16(0x18);
	if (RBIOS8(tmp + 0x14) != 0x0) {
		DRM_INFO("Not an x86 BIOS ROM, not using.\n");
		goto free_bios;
	}

	adev->bios_header_start = RBIOS16(0x48);
	if (!adev->bios_header_start) {
		goto free_bios;
	}
	tmp = adev->bios_header_start + 4;
	if (!memcmp(adev->bios + tmp, "ATOM", 4) ||
	    !memcmp(adev->bios + tmp, "MOTA", 4)) {
		adev->is_atom_bios = true;
	} else {
		adev->is_atom_bios = false;
	}

	DRM_DEBUG("%sBIOS detected\n", adev->is_atom_bios ? "ATOM" : "COM");
	return true;
free_bios:
	kfree(adev->bios);
	adev->bios = NULL;
	return false;
}