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| author | Sean Paul <seanpaul@chromium.org> | 2019-04-10 15:50:49 -0400 |
|---|---|---|
| committer | Sean Paul <seanpaul@chromium.org> | 2019-04-10 15:50:49 -0400 |
| commit | 3bfaf1f7044c6a3b1e00fcad2d0529f0da449d67 (patch) | |
| tree | 490bc7e8aa29c2ee41eb4813683f1aa23971abd3 /drivers/firmware/efi/earlycon.c | |
| parent | 669105a74a287b14cdec04c64eb51db1bb890f64 (diff) | |
| parent | 14d2bd53a47a7e1cb3e03d00a6b952734cf90f3f (diff) | |
| download | talos-op-linux-3bfaf1f7044c6a3b1e00fcad2d0529f0da449d67.tar.gz talos-op-linux-3bfaf1f7044c6a3b1e00fcad2d0529f0da449d67.zip | |
Merge drm/drm-next into drm-misc-next
Finally have a reason for a backmerge other than "it's been a while"!
Backmerging drm-next to -misc-next to facilitate Rob Herring's work on
Panfrost.
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Diffstat (limited to 'drivers/firmware/efi/earlycon.c')
| -rw-r--r-- | drivers/firmware/efi/earlycon.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/drivers/firmware/efi/earlycon.c b/drivers/firmware/efi/earlycon.c new file mode 100644 index 000000000000..c9a0efca17b0 --- /dev/null +++ b/drivers/firmware/efi/earlycon.c @@ -0,0 +1,206 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2013 Intel Corporation; author Matt Fleming + */ + +#include <linux/console.h> +#include <linux/efi.h> +#include <linux/font.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/serial_core.h> +#include <linux/screen_info.h> + +#include <asm/early_ioremap.h> + +static const struct font_desc *font; +static u32 efi_x, efi_y; +static u64 fb_base; +static pgprot_t fb_prot; + +static __ref void *efi_earlycon_map(unsigned long start, unsigned long len) +{ + return early_memremap_prot(fb_base + start, len, pgprot_val(fb_prot)); +} + +static __ref void efi_earlycon_unmap(void *addr, unsigned long len) +{ + early_memunmap(addr, len); +} + +static void efi_earlycon_clear_scanline(unsigned int y) +{ + unsigned long *dst; + u16 len; + + len = screen_info.lfb_linelength; + dst = efi_earlycon_map(y*len, len); + if (!dst) + return; + + memset(dst, 0, len); + efi_earlycon_unmap(dst, len); +} + +static void efi_earlycon_scroll_up(void) +{ + unsigned long *dst, *src; + u16 len; + u32 i, height; + + len = screen_info.lfb_linelength; + height = screen_info.lfb_height; + + for (i = 0; i < height - font->height; i++) { + dst = efi_earlycon_map(i*len, len); + if (!dst) + return; + + src = efi_earlycon_map((i + font->height) * len, len); + if (!src) { + efi_earlycon_unmap(dst, len); + return; + } + + memmove(dst, src, len); + + efi_earlycon_unmap(src, len); + efi_earlycon_unmap(dst, len); + } +} + +static void efi_earlycon_write_char(u32 *dst, unsigned char c, unsigned int h) +{ + const u32 color_black = 0x00000000; + const u32 color_white = 0x00ffffff; + const u8 *src; + u8 s8; + int m; + + src = font->data + c * font->height; + s8 = *(src + h); + + for (m = 0; m < 8; m++) { + if ((s8 >> (7 - m)) & 1) + *dst = color_white; + else + *dst = color_black; + dst++; + } +} + +static void +efi_earlycon_write(struct console *con, const char *str, unsigned int num) +{ + struct screen_info *si; + unsigned int len; + const char *s; + void *dst; + + si = &screen_info; + len = si->lfb_linelength; + + while (num) { + unsigned int linemax; + unsigned int h, count = 0; + + for (s = str; *s && *s != '\n'; s++) { + if (count == num) + break; + count++; + } + + linemax = (si->lfb_width - efi_x) / font->width; + if (count > linemax) + count = linemax; + + for (h = 0; h < font->height; h++) { + unsigned int n, x; + + dst = efi_earlycon_map((efi_y + h) * len, len); + if (!dst) + return; + + s = str; + n = count; + x = efi_x; + + while (n-- > 0) { + efi_earlycon_write_char(dst + x*4, *s, h); + x += font->width; + s++; + } + + efi_earlycon_unmap(dst, len); + } + + num -= count; + efi_x += count * font->width; + str += count; + + if (num > 0 && *s == '\n') { + efi_x = 0; + efi_y += font->height; + str++; + num--; + } + + if (efi_x + font->width > si->lfb_width) { + efi_x = 0; + efi_y += font->height; + } + + if (efi_y + font->height > si->lfb_height) { + u32 i; + + efi_y -= font->height; + efi_earlycon_scroll_up(); + + for (i = 0; i < font->height; i++) + efi_earlycon_clear_scanline(efi_y + i); + } + } +} + +static int __init efi_earlycon_setup(struct earlycon_device *device, + const char *opt) +{ + struct screen_info *si; + u16 xres, yres; + u32 i; + + if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI) + return -ENODEV; + + fb_base = screen_info.lfb_base; + if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) + fb_base |= (u64)screen_info.ext_lfb_base << 32; + + if (opt && !strcmp(opt, "ram")) + fb_prot = PAGE_KERNEL; + else + fb_prot = pgprot_writecombine(PAGE_KERNEL); + + si = &screen_info; + xres = si->lfb_width; + yres = si->lfb_height; + + /* + * efi_earlycon_write_char() implicitly assumes a framebuffer with + * 32 bits per pixel. + */ + if (si->lfb_depth != 32) + return -ENODEV; + + font = get_default_font(xres, yres, -1, -1); + if (!font) + return -ENODEV; + + efi_y = rounddown(yres, font->height) - font->height; + for (i = 0; i < (yres - efi_y) / font->height; i++) + efi_earlycon_scroll_up(); + + device->con->write = efi_earlycon_write; + return 0; +} +EARLYCON_DECLARE(efifb, efi_earlycon_setup); |

