Commit-ID:  69c1f396f25b805aeff08f06d2e992c315ee5b1e
Gitweb:     https://git.kernel.org/tip/69c1f396f25b805aeff08f06d2e992c315ee5b1e
Author:     Ard Biesheuvel <ard.biesheu...@linaro.org>
AuthorDate: Sat, 2 Feb 2019 10:41:18 +0100
Committer:  Ingo Molnar <mi...@kernel.org>
CommitDate: Mon, 4 Feb 2019 08:27:30 +0100

efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation

Move the x86 EFI earlyprintk implementation to a shared location under
drivers/firmware and tweak it slightly so we can expose it as an earlycon
implementation (which is generic) rather than earlyprintk (which is only
implemented for a few architectures)

This also involves switching to write-combine mappings by default (which
is required on ARM since device mappings lack memory semantics, and so
memcpy/memset may not be used on them), and adding support for shared
memory framebuffers on cache coherent non-x86 systems (which do not
tolerate mismatched attributes).

Note that 32-bit ARM does not populate its struct screen_info early
enough for earlycon=efifb to work, so it is disabled there.

Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
Reviewed-by: Alexander Graf <ag...@suse.de>
Cc: AKASHI Takahiro <takahiro.aka...@linaro.org>
Cc: Bjorn Andersson <bjorn.anders...@linaro.org>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Heinrich Schuchardt <xypron.g...@gmx.de>
Cc: Jeffrey Hugo <jh...@codeaurora.org>
Cc: Lee Jones <lee.jo...@linaro.org>
Cc: Leif Lindholm <leif.lindh...@linaro.org>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Matt Fleming <m...@codeblueprint.co.uk>
Cc: Peter Jones <pjo...@redhat.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prak...@intel.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: linux-...@vger.kernel.org
Link: http://lkml.kernel.org/r/20190202094119.13230-10-ard.biesheu...@linaro.org
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
 Documentation/admin-guide/kernel-parameters.txt |   8 +-
 arch/x86/Kconfig.debug                          |  10 -
 arch/x86/include/asm/efi.h                      |   1 -
 arch/x86/kernel/early_printk.c                  |   4 -
 arch/x86/platform/efi/Makefile                  |   1 -
 arch/x86/platform/efi/early_printk.c            | 240 ------------------------
 drivers/firmware/efi/Kconfig                    |   6 +
 drivers/firmware/efi/Makefile                   |   1 +
 drivers/firmware/efi/earlycon.c                 | 206 ++++++++++++++++++++
 9 files changed, 220 insertions(+), 257 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt 
b/Documentation/admin-guide/kernel-parameters.txt
index b799bcf67d7b..76dd3baa31e0 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1073,9 +1073,15 @@
                        specified address. The serial port must already be
                        setup and configured. Options are not yet supported.
 
+               efifb,[options]
+                       Start an early, unaccelerated console on the EFI
+                       memory mapped framebuffer (if available). On cache
+                       coherent non-x86 systems that use system memory for
+                       the framebuffer, pass the 'ram' option so that it is
+                       mapped with the correct attributes.
+
        earlyprintk=    [X86,SH,ARM,M68k,S390]
                        earlyprintk=vga
-                       earlyprintk=efi
                        earlyprintk=sclp
                        earlyprintk=xen
                        earlyprintk=serial[,ttySn[,baudrate]]
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 0723dff17e6c..15d0fbe27872 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -40,16 +40,6 @@ config EARLY_PRINTK_DBGP
          with klogd/syslogd or the X server. You should normally say N here,
          unless you want to debug such a crash. You need usb debug device.
 
-config EARLY_PRINTK_EFI
-       bool "Early printk via the EFI framebuffer"
-       depends on EFI && EARLY_PRINTK
-       select FONT_SUPPORT
-       ---help---
-         Write kernel log output directly into the EFI framebuffer.
-
-         This is useful for kernel debugging when your machine crashes very
-         early before the console code is initialized.
-
 config EARLY_PRINTK_USB_XDBC
        bool "Early printk via the xHCI debug port"
        depends on EARLY_PRINTK && PCI
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 107283b1eb1e..606a4b6a9812 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -170,7 +170,6 @@ static inline bool efi_runtime_supported(void)
        return false;
 }
 
-extern struct console early_efi_console;
 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
 
 extern void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index 374a52fa5296..9b33904251a9 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -388,10 +388,6 @@ static int __init setup_early_printk(char *buf)
                if (!strncmp(buf, "xen", 3))
                        early_console_register(&xenboot_console, keep);
 #endif
-#ifdef CONFIG_EARLY_PRINTK_EFI
-               if (!strncmp(buf, "efi", 3))
-                       early_console_register(&early_efi_console, keep);
-#endif
 #ifdef CONFIG_EARLY_PRINTK_USB_XDBC
                if (!strncmp(buf, "xdbc", 4))
                        early_xdbc_parse_parameter(buf + 4);
diff --git a/arch/x86/platform/efi/Makefile b/arch/x86/platform/efi/Makefile
index e4dc3862d423..fe29f3f5d384 100644
--- a/arch/x86/platform/efi/Makefile
+++ b/arch/x86/platform/efi/Makefile
@@ -3,5 +3,4 @@ OBJECT_FILES_NON_STANDARD_efi_thunk_$(BITS).o := y
 OBJECT_FILES_NON_STANDARD_efi_stub_$(BITS).o := y
 
 obj-$(CONFIG_EFI)              += quirks.o efi.o efi_$(BITS).o 
efi_stub_$(BITS).o
-obj-$(CONFIG_EARLY_PRINTK_EFI) += early_printk.o
 obj-$(CONFIG_EFI_MIXED)                += efi_thunk_$(BITS).o
diff --git a/arch/x86/platform/efi/early_printk.c 
b/arch/x86/platform/efi/early_printk.c
deleted file mode 100644
index 7138bc7a265c..000000000000
--- a/arch/x86/platform/efi/early_printk.c
+++ /dev/null
@@ -1,240 +0,0 @@
-/*
- * Copyright (C) 2013 Intel Corporation; author Matt Fleming
- *
- *  This file is part of the Linux kernel, and is made available under
- *  the terms of the GNU General Public License version 2.
- */
-
-#include <linux/console.h>
-#include <linux/efi.h>
-#include <linux/font.h>
-#include <linux/io.h>
-#include <linux/kernel.h>
-#include <asm/setup.h>
-
-static const struct font_desc *font;
-static u32 efi_x, efi_y;
-static void *efi_fb;
-static bool early_efi_keep;
-
-/*
- * efi earlyprintk need use early_ioremap to map the framebuffer.
- * But early_ioremap is not usable for earlyprintk=efi,keep, ioremap should
- * be used instead. ioremap will be available after paging_init() which is
- * earlier than initcall callbacks. Thus adding this early initcall function
- * early_efi_map_fb to map the whole efi framebuffer.
- */
-static __init int early_efi_map_fb(void)
-{
-       u64 base, size;
-
-       if (!early_efi_keep)
-               return 0;
-
-       base = boot_params.screen_info.lfb_base;
-       if (boot_params.screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
-               base |= (u64)boot_params.screen_info.ext_lfb_base << 32;
-       size = boot_params.screen_info.lfb_size;
-       efi_fb = ioremap(base, size);
-
-       return efi_fb ? 0 : -ENOMEM;
-}
-early_initcall(early_efi_map_fb);
-
-/*
- * early_efi_map maps efi framebuffer region [start, start + len -1]
- * In case earlyprintk=efi,keep we have the whole framebuffer mapped already
- * so just return the offset efi_fb + start.
- */
-static __ref void *early_efi_map(unsigned long start, unsigned long len)
-{
-       u64 base;
-
-       base = boot_params.screen_info.lfb_base;
-       if (boot_params.screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
-               base |= (u64)boot_params.screen_info.ext_lfb_base << 32;
-
-       if (efi_fb)
-               return (efi_fb + start);
-       else
-               return early_ioremap(base + start, len);
-}
-
-static __ref void early_efi_unmap(void *addr, unsigned long len)
-{
-       if (!efi_fb)
-               early_iounmap(addr, len);
-}
-
-static void early_efi_clear_scanline(unsigned int y)
-{
-       unsigned long *dst;
-       u16 len;
-
-       len = boot_params.screen_info.lfb_linelength;
-       dst = early_efi_map(y*len, len);
-       if (!dst)
-               return;
-
-       memset(dst, 0, len);
-       early_efi_unmap(dst, len);
-}
-
-static void early_efi_scroll_up(void)
-{
-       unsigned long *dst, *src;
-       u16 len;
-       u32 i, height;
-
-       len = boot_params.screen_info.lfb_linelength;
-       height = boot_params.screen_info.lfb_height;
-
-       for (i = 0; i < height - font->height; i++) {
-               dst = early_efi_map(i*len, len);
-               if (!dst)
-                       return;
-
-               src = early_efi_map((i + font->height) * len, len);
-               if (!src) {
-                       early_efi_unmap(dst, len);
-                       return;
-               }
-
-               memmove(dst, src, len);
-
-               early_efi_unmap(src, len);
-               early_efi_unmap(dst, len);
-       }
-}
-
-static void early_efi_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
-early_efi_write(struct console *con, const char *str, unsigned int num)
-{
-       struct screen_info *si;
-       unsigned int len;
-       const char *s;
-       void *dst;
-
-       si = &boot_params.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 = early_efi_map((efi_y + h) * len, len);
-                       if (!dst)
-                               return;
-
-                       s = str;
-                       n = count;
-                       x = efi_x;
-
-                       while (n-- > 0) {
-                               early_efi_write_char(dst + x*4, *s, h);
-                               x += font->width;
-                               s++;
-                       }
-
-                       early_efi_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;
-                       early_efi_scroll_up();
-
-                       for (i = 0; i < font->height; i++)
-                               early_efi_clear_scanline(efi_y + i);
-               }
-       }
-}
-
-static __init int early_efi_setup(struct console *con, char *options)
-{
-       struct screen_info *si;
-       u16 xres, yres;
-       u32 i;
-
-       si = &boot_params.screen_info;
-       xres = si->lfb_width;
-       yres = si->lfb_height;
-
-       /*
-        * early_efi_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++)
-               early_efi_scroll_up();
-
-       /* early_console_register will unset CON_BOOT in case ,keep */
-       if (!(con->flags & CON_BOOT))
-               early_efi_keep = true;
-       return 0;
-}
-
-struct console early_efi_console = {
-       .name =         "earlyefi",
-       .write =        early_efi_write,
-       .setup =        early_efi_setup,
-       .flags =        CON_PRINTBUFFER,
-       .index =        -1,
-};
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 89110dfc7127..190be0b1d109 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -198,3 +198,9 @@ config EFI_DEV_PATH_PARSER
        bool
        depends on ACPI
        default n
+
+config EFI_EARLYCON
+       def_bool y
+       depends on SERIAL_EARLYCON && !ARM && !IA64
+       select FONT_SUPPORT
+       select ARCH_USE_MEMREMAP_PROT
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index 5f9f5039de50..d2d0d2030620 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -30,5 +30,6 @@ arm-obj-$(CONFIG_EFI)                 := arm-init.o 
arm-runtime.o
 obj-$(CONFIG_ARM)                      += $(arm-obj-y)
 obj-$(CONFIG_ARM64)                    += $(arm-obj-y)
 obj-$(CONFIG_EFI_CAPSULE_LOADER)       += capsule-loader.o
+obj-$(CONFIG_EFI_EARLYCON)             += earlycon.o
 obj-$(CONFIG_UEFI_CPER_ARM)            += cper-arm.o
 obj-$(CONFIG_UEFI_CPER_X86)            += cper-x86.o
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);

Reply via email to