/*-
 * Copyright (c) 2013 The FreeBSD Foundation
 * All rights reserved.
 *
 * This software was developed by Benno Rice under sponsorship from
 * the FreeBSD Foundation.
 * 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 THE AUTHOR 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 AUTHOR 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: head/sys/boot/efi/loader/arch/amd64/framebuffer.c 304532 2016-08-20 16:23:19Z tsoome $
 */

#include <bootstrap.h>
#include <sys/endian.h>
#include <stand.h>

#include <efi.h>
#include <efilib.h>

#include <machine/metadata.h>

#include "framebuffer.h"

static EFI_GUID gop_guid = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
static EFI_GUID pciio_guid = EFI_PCI_IO_PROTOCOL_GUID;
static EFI_GUID uga_guid = EFI_UGA_DRAW_PROTOCOL_GUID;

u_int
efi_framebuffer_bpp(struct efi_fb *efifb)
{
        uint32_t mask;
        u_int depth;

        mask = efifb->fb_mask_red | efifb->fb_mask_green |
            efifb->fb_mask_blue | efifb->fb_mask_reserved;
        if (mask == 0)
                return (0);
        for (depth = 1; mask != 1; depth++)
                mask >>= 1;
        return (depth);
}

static int
efifb_mask_from_pixfmt(struct efi_fb *efifb, EFI_GRAPHICS_PIXEL_FORMAT pixfmt,
    EFI_PIXEL_BITMASK *pixinfo)
{
        int result;

        result = 0;
        switch (pixfmt) {
        case PixelRedGreenBlueReserved8BitPerColor:
                efifb->fb_mask_red = 0x000000ff;
                efifb->fb_mask_green = 0x0000ff00;
                efifb->fb_mask_blue = 0x00ff0000;
                efifb->fb_mask_reserved = 0xff000000;
                break;
        case PixelBlueGreenRedReserved8BitPerColor:
                efifb->fb_mask_red = 0x00ff0000;
                efifb->fb_mask_green = 0x0000ff00;
                efifb->fb_mask_blue = 0x000000ff;
                efifb->fb_mask_reserved = 0xff000000;
                break;
        case PixelBitMask:
                efifb->fb_mask_red = pixinfo->RedMask;
                efifb->fb_mask_green = pixinfo->GreenMask;
                efifb->fb_mask_blue = pixinfo->BlueMask;
                efifb->fb_mask_reserved = pixinfo->ReservedMask;
                break;
        default:
                result = 1;
                break;
        }
        return (result);
}

static int
efifb_from_gop(struct efi_fb *efifb, EFI_GRAPHICS_OUTPUT_PROTOCOL_MODE *mode,
    EFI_GRAPHICS_OUTPUT_MODE_INFORMATION *info)
{
        int result;

        efifb->fb_addr = mode->FrameBufferBase;
        efifb->fb_size = mode->FrameBufferSize;
        efifb->fb_height = info->VerticalResolution;
        efifb->fb_width = info->HorizontalResolution;
        efifb->fb_stride = info->PixelsPerScanLine;
        result = efifb_mask_from_pixfmt(efifb, info->PixelFormat,
            &info->PixelInformation);
        return (result);
}

static ssize_t
efifb_uga_find_pixel(EFI_UGA_DRAW_PROTOCOL *uga, u_int line,
    EFI_PCI_IO_PROTOCOL *pciio, uint64_t addr, uint64_t size)
{
        EFI_UGA_PIXEL pix0, pix1;
        uint8_t *data1, *data2;
        size_t count, maxcount = 1024;
        ssize_t ofs;
        EFI_STATUS status;
        u_int idx;

        status = uga->Blt(uga, &pix0, EfiUgaVideoToBltBuffer,
            0, line, 0, 0, 1, 1, 0);
        if (EFI_ERROR(status)) {
                printf("UGA BLT operation failed (video->buffer)");
                return (-1);
        }
        pix1.Red = ~pix0.Red;
        pix1.Green = ~pix0.Green;
        pix1.Blue = ~pix0.Blue;
        pix1.Reserved = 0;

        data1 = calloc(maxcount, 2);
        if (data1 == NULL) {
                printf("Unable to allocate memory");
                return (-1);
        }
        data2 = data1 + maxcount;

        ofs = 0;
        while (size > 0) {
                count = min(size, maxcount);

                status = pciio->Mem.Read(pciio, EfiPciIoWidthUint32,
                    EFI_PCI_IO_PASS_THROUGH_BAR, addr + ofs, count >> 2,
                    data1);
                if (EFI_ERROR(status)) {
                        printf("Error reading frame buffer (before)");
                        goto fail;
                }
                status = uga->Blt(uga, &pix1, EfiUgaBltBufferToVideo,
                    0, 0, 0, line, 1, 1, 0);
                if (EFI_ERROR(status)) {
                        printf("UGA BLT operation failed (modify)");
                        goto fail;
                }
                status = pciio->Mem.Read(pciio, EfiPciIoWidthUint32,
                    EFI_PCI_IO_PASS_THROUGH_BAR, addr + ofs, count >> 2,
                    data2);
                if (EFI_ERROR(status)) {
                        printf("Error reading frame buffer (after)");
                        goto fail;
                }
                status = uga->Blt(uga, &pix0, EfiUgaBltBufferToVideo,
                    0, 0, 0, line, 1, 1, 0);
                if (EFI_ERROR(status)) {
                        printf("UGA BLT operation failed (restore)");
                        goto fail;
                }
                for (idx = 0; idx < count; idx++) {
                        if (data1[idx] != data2[idx]) {
                                free(data1);
                                return (ofs + (idx & ~3));
                        }
                }
                ofs += count;
                size -= count;
        }
        printf("No change detected in frame buffer");

 fail:
        printf(" -- error %llu\n", status);
        free(data1);
        return (-1);
}

static EFI_PCI_IO_PROTOCOL *
efifb_uga_get_pciio(void)
{
        EFI_PCI_IO_PROTOCOL *pciio;
        EFI_HANDLE *buf, *hp;
        EFI_STATUS status;
        UINTN bufsz;

        /* Get all handles that support the UGA protocol. */
        bufsz = 0;
        status = BS->LocateHandle(ByProtocol, &uga_guid, NULL, &bufsz, NULL);
        if (status != EFI_BUFFER_TOO_SMALL)
                return (NULL);
        buf = malloc(bufsz);
        status = BS->LocateHandle(ByProtocol, &uga_guid, NULL, &bufsz, buf);
        if (status != EFI_SUCCESS) {
                free(buf);
                return (NULL);
        }
        bufsz /= sizeof(EFI_HANDLE);

        /* Get the PCI I/O interface of the first handle that supports it. */
        pciio = NULL;
        for (hp = buf; hp < buf + bufsz; hp++) {
                status = OpenProtocolByHandle(*hp, &pciio_guid,
                    (void **)&pciio);
                if (status == EFI_SUCCESS) {
                        free(buf);
                        return (pciio);
                }
        }
        free(buf);
        return (NULL);
}

static EFI_STATUS
efifb_uga_locate_framebuffer(EFI_PCI_IO_PROTOCOL *pciio, uint64_t *addrp,
    uint64_t *sizep)
{
        uint8_t *resattr;
        uint64_t addr, size;
        EFI_STATUS status;
        u_int bar;

        if (pciio == NULL)
                return (EFI_DEVICE_ERROR);

        /* Attempt to get the frame buffer address (imprecise). */
        *addrp = 0;
        *sizep = 0;
        for (bar = 0; bar < 6; bar++) {
                status = pciio->GetBarAttributes(pciio, bar, NULL,
                    (void **)&resattr);
                if (status != EFI_SUCCESS)
                        continue;
                /* XXX magic offsets and constants. */
                if (resattr[0] == 0x87 && resattr[3] == 0) {
                        /* 32-bit address space descriptor (MEMIO) */
                        addr = le32dec(resattr + 10);
                        size = le32dec(resattr + 22);
                } else if (resattr[0] == 0x8a && resattr[3] == 0) {
                        /* 64-bit address space descriptor (MEMIO) */
                        addr = le64dec(resattr + 14);
                        size = le64dec(resattr + 38);
                } else {
                        addr = 0;
                        size = 0;
                }
                BS->FreePool(resattr);
                if (addr == 0 || size == 0)
                        continue;

                /* We assume the largest BAR is the frame buffer. */
                if (size > *sizep) {
                        *addrp = addr;
                        *sizep = size;
                }
        }
        return ((*addrp == 0 || *sizep == 0) ? EFI_DEVICE_ERROR : 0);
}

static int
efifb_from_uga(struct efi_fb *efifb, EFI_UGA_DRAW_PROTOCOL *uga)
{
        EFI_PCI_IO_PROTOCOL *pciio;
        char *ev, *p;
        EFI_STATUS status;
        ssize_t offset;
        uint64_t fbaddr;
        uint32_t horiz, vert, stride;
        uint32_t np, depth, refresh;

        status = uga->GetMode(uga, &horiz, &vert, &depth, &refresh);
        if (EFI_ERROR(status))
                return (1);
        efifb->fb_height = vert;
        efifb->fb_width = horiz;
        /* Paranoia... */
        if (efifb->fb_height == 0 || efifb->fb_width == 0)
                return (1);

        /* The color masks are fixed AFAICT. */
        efifb_mask_from_pixfmt(efifb, PixelBlueGreenRedReserved8BitPerColor,
            NULL);

        /* pciio can be NULL on return! */
        pciio = efifb_uga_get_pciio();

        /* Try to find the frame buffer. */
        status = efifb_uga_locate_framebuffer(pciio, &efifb->fb_addr,
            &efifb->fb_size);
        if (EFI_ERROR(status)) {
                efifb->fb_addr = 0;
                efifb->fb_size = 0;
        }

        /*
         * There's no reliable way to detect the frame buffer or the
         * offset within the frame buffer of the visible region, nor
         * the stride. Our only option is to look at the system and
         * fill in the blanks based on that. Luckily, UGA was mostly
         * only used on Apple hardware.
         */
        offset = -1;
        ev = getenv("smbios.system.maker");
        if (ev != NULL && !strcmp(ev, "Apple Inc.")) {
                ev = getenv("smbios.system.product");
                if (ev != NULL && !strcmp(ev, "iMac7,1")) {
                        /* These are the expected values we should have. */
                        horiz = 1680;
                        vert = 1050;
                        fbaddr = 0xc0000000;
                        /* These are the missing bits. */
                        offset = 0x10000;
                        stride = 1728;
                } else if (ev != NULL && !strcmp(ev, "MacBook3,1")) {
                        /* These are the expected values we should have. */
                        horiz = 1280;
                        vert = 800;
                        fbaddr = 0xc0000000;
                        /* These are the missing bits. */
                        offset = 0x0;
                        stride = 2048;
                }
        }

        /*
         * If this is hardware we know, make sure that it looks familiar
         * before we accept our hardcoded values.
         */
        if (offset >= 0 && efifb->fb_width == horiz &&
            efifb->fb_height == vert && efifb->fb_addr == fbaddr) {
                efifb->fb_addr += offset;
                efifb->fb_size -= offset;
                efifb->fb_stride = stride;
                return (0);
        } else if (offset >= 0) {
                printf("Hardware make/model known, but graphics not "
                    "as expected.\n");
                printf("Console may not work!\n");
        }

        /*
         * The stride is equal or larger to the width. Often it's the
         * next larger power of two. We'll start with that...
         */
        efifb->fb_stride = efifb->fb_width;
        do {
                np = efifb->fb_stride & (efifb->fb_stride - 1);
                if (np) {
                        efifb->fb_stride |= (np - 1);
                        efifb->fb_stride++;
                }
        } while (np);

        ev = getenv("hw.efifb.address");
        if (ev == NULL) {
                if (efifb->fb_addr == 0) {
                        printf("Please set hw.efifb.address and "
                            "hw.efifb.stride.\n");
                        return (1);
                }

                /*
                 * The visible part of the frame buffer may not start at
                 * offset 0, so try to detect it. Note that we may not
                 * always be able to read from the frame buffer, which
                 * means that we may not be able to detect anything. In
                 * that case, we would take a long time scanning for a
                 * pixel change in the frame buffer, which would have it
                 * appear that we're hanging, so we limit the scan to
                 * 1/256th of the frame buffer. This number is mostly
                 * based on PR 202730 and the fact that on a MacBoook,
                 * where we can't read from the frame buffer the offset
                 * of the visible region is 0. In short: we want to scan
                 * enough to handle all adapters that have an offset
                 * larger than 0 and we want to scan as little as we can
                 * to not appear to hang when we can't read from the
                 * frame buffer.
                 */
                offset = efifb_uga_find_pixel(uga, 0, pciio, efifb->fb_addr,
                    efifb->fb_size >> 8);
                if (offset == -1) {
                        printf("Unable to reliably detect frame buffer.\n");
                } else if (offset > 0) {
                        efifb->fb_addr += offset;
                        efifb->fb_size -= offset;
                }
        } else {
                offset = 0;
                efifb->fb_size = efifb->fb_height * efifb->fb_stride * 4;
                efifb->fb_addr = strtoul(ev, &p, 0);
                if (*p != '\0')
                        return (1);
        }

        ev = getenv("hw.efifb.stride");
        if (ev == NULL) {
                if (pciio != NULL && offset != -1) {
                        /* Determine the stride. */
                        offset = efifb_uga_find_pixel(uga, 1, pciio,
                            efifb->fb_addr, horiz * 8);
                        if (offset != -1)
                                efifb->fb_stride = offset >> 2;
                } else {
                        printf("Unable to reliably detect the stride.\n");
                }
        } else {
                efifb->fb_stride = strtoul(ev, &p, 0);
                if (*p != '\0')
                        return (1);
        }

        /*
         * We finalized on the stride, so recalculate the size of the
         * frame buffer.
         */
        efifb->fb_size = efifb->fb_height * efifb->fb_stride * 4;
        return (0);
}

int
efi_find_framebuffer(struct efi_fb *efifb)
{
        EFI_GRAPHICS_OUTPUT_PROTOCOL *gop;
        EFI_UGA_DRAW_PROTOCOL *uga;
        EFI_STATUS status;

        status = BS->LocateProtocol(&gop_guid, NULL, (VOID **)&gop);
        if (status == EFI_SUCCESS)
                return (efifb_from_gop(efifb, gop->Mode, gop->Mode->Info));

        status = BS->LocateProtocol(&uga_guid, NULL, (VOID **)&uga);
        if (status == EFI_SUCCESS)
                return (efifb_from_uga(efifb, uga));

        return (1);
}

static void
print_efifb(int mode, struct efi_fb *efifb, int verbose)
{
        u_int depth;

        if (mode >= 0)
                printf("mode %d: ", mode);
        depth = efi_framebuffer_bpp(efifb);
        printf("%ux%ux%u, stride=%u", efifb->fb_width, efifb->fb_height,
            depth, efifb->fb_stride);
        if (verbose) {
                printf("\n    frame buffer: address=%jx, size=%jx",
                    (uintmax_t)efifb->fb_addr, (uintmax_t)efifb->fb_size);
                printf("\n    color mask: R=%08x, G=%08x, B=%08x\n",
                    efifb->fb_mask_red, efifb->fb_mask_green,
                    efifb->fb_mask_blue);
        }
}

COMMAND_SET(gop, "gop", "graphics output protocol", command_gop);

static int
command_gop(int argc, char *argv[])
{
        struct efi_fb efifb;
        EFI_GRAPHICS_OUTPUT_PROTOCOL *gop;
        EFI_STATUS status;
        u_int mode;

        status = BS->LocateProtocol(&gop_guid, NULL, (VOID **)&gop);
        if (EFI_ERROR(status)) {
                snprintf(command_errbuf, sizeof(command_errbuf),
                    "%s: Graphics Output Protocol not present (error=%llu)",
                    argv[0], status);
                return (CMD_ERROR);
        }

        if (argc < 2)
                goto usage;

        if (!strcmp(argv[1], "set")) {
                char *cp;

                if (argc != 3)
                        goto usage;
                mode = strtol(argv[2], &cp, 0);
                if (cp[0] != '\0') {
                        sprintf(command_errbuf, "mode is an integer");
                        return (CMD_ERROR);
                }
                status = gop->SetMode(gop, mode);
                if (EFI_ERROR(status)) {
                        snprintf(command_errbuf, sizeof(command_errbuf),
                            "%s: Unable to set mode to %u (error=%llu)",
                            argv[0], mode, status);
                        return (CMD_ERROR);
                }
        } else if (!strcmp(argv[1], "get")) {
                if (argc != 2)
                        goto usage;
                efifb_from_gop(&efifb, gop->Mode, gop->Mode->Info);
                print_efifb(gop->Mode->Mode, &efifb, 1);
                printf("\n");
        } else if (!strcmp(argv[1], "list")) {
                EFI_GRAPHICS_OUTPUT_MODE_INFORMATION *info;
                UINTN infosz;

                if (argc != 2)
                        goto usage;
                pager_open();
                for (mode = 0; mode < gop->Mode->MaxMode; mode++) {
                        status = gop->QueryMode(gop, mode, &infosz, &info);
                        if (EFI_ERROR(status))
                                continue;
                        efifb_from_gop(&efifb, gop->Mode, info);
                        print_efifb(mode, &efifb, 0);
                        if (pager_output("\n"))
                                break;
                }
                pager_close();
        }
        return (CMD_OK);

 usage:
        snprintf(command_errbuf, sizeof(command_errbuf),
            "usage: %s [list | get | set <mode>]", argv[0]);
        return (CMD_ERROR);
}

COMMAND_SET(uga, "uga", "universal graphics adapter", command_uga);

static int
command_uga(int argc, char *argv[])
{
        struct efi_fb efifb;
        EFI_UGA_DRAW_PROTOCOL *uga;
        EFI_STATUS status;

        status = BS->LocateProtocol(&uga_guid, NULL, (VOID **)&uga);
        if (EFI_ERROR(status)) {
                snprintf(command_errbuf, sizeof(command_errbuf),
                    "%s: UGA Protocol not present (error=%llu)",
                    argv[0], status);
                return (CMD_ERROR);
        }

        if (argc != 1)
                goto usage;

        if (efifb_from_uga(&efifb, uga) != CMD_OK) {
                snprintf(command_errbuf, sizeof(command_errbuf),
                    "%s: Unable to get UGA information", argv[0]);
                return (CMD_ERROR);
        }

        print_efifb(-1, &efifb, 1);
        printf("\n");
        return (CMD_OK);

 usage:
        snprintf(command_errbuf, sizeof(command_errbuf), "usage: %s", argv[0]);
        return (CMD_ERROR);
}