From 5f35eb0e29ca26da82febe49d7698dbeb8882ea0 Mon Sep 17 00:00:00 2001 From: Dave Young Date: Thu, 1 May 2014 21:15:48 +0800 Subject: [PATCH] x86/efi: earlyprintk=efi,keep fix earlyprintk=efi,keep will cause kernel hangs while freeing initmem like below: VFS: Mounted root (ext4 filesystem) readonly on device 254:2. devtmpfs: mounted Freeing unused kernel memory: 880K (ffffffff817d4000 - ffffffff818b0000) It is caused by efi earlyprintk use __init function which will be freed later. Such as early_efi_write is marked as __init, also it will use early_ioremap which is init function as well. To fix this issue, I added early initcall early_efi_map_fb which maps the whole efi fb for later use. OTOH, adding a wrapper function early_efi_map which calls early_ioremap before ioremap is available. With this patch applied efi boot ok with earlyprintk=efi,keep console=efi Signed-off-by: Dave Young Signed-off-by: Matt Fleming --- arch/x86/platform/efi/early_printk.c | 83 +++++++++++++++++++++------- 1 file changed, 64 insertions(+), 19 deletions(-) diff --git a/arch/x86/platform/efi/early_printk.c b/arch/x86/platform/efi/early_printk.c index 81b506d5befd..524142117296 100644 --- a/arch/x86/platform/efi/early_printk.c +++ b/arch/x86/platform/efi/early_printk.c @@ -14,48 +14,92 @@ static const struct font_desc *font; static u32 efi_x, efi_y; +static void *efi_fb; +static bool early_efi_keep; -static __init void early_efi_clear_scanline(unsigned int y) +/* + * 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) { - unsigned long base, *dst; - u16 len; + unsigned long base, size; + + if (!early_efi_keep) + return 0; base = boot_params.screen_info.lfb_base; - len = boot_params.screen_info.lfb_linelength; + 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 __init_refok void *early_efi_map(unsigned long start, unsigned long len) +{ + unsigned long base; + + base = boot_params.screen_info.lfb_base; + + if (efi_fb) + return (efi_fb + start); + else + return early_ioremap(base + start, len); +} - dst = early_ioremap(base + y*len, len); +static __init_refok 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_iounmap(dst, len); + early_efi_unmap(dst, len); } -static __init void early_efi_scroll_up(void) +static void early_efi_scroll_up(void) { - unsigned long base, *dst, *src; + unsigned long *dst, *src; u16 len; u32 i, height; - base = boot_params.screen_info.lfb_base; len = boot_params.screen_info.lfb_linelength; height = boot_params.screen_info.lfb_height; for (i = 0; i < height - font->height; i++) { - dst = early_ioremap(base + i*len, len); + dst = early_efi_map(i*len, len); if (!dst) return; - src = early_ioremap(base + (i + font->height) * len, len); + src = early_efi_map((i + font->height) * len, len); if (!src) { - early_iounmap(dst, len); + early_efi_unmap(dst, len); return; } memmove(dst, src, len); - early_iounmap(src, len); - early_iounmap(dst, len); + early_efi_unmap(src, len); + early_efi_unmap(dst, len); } } @@ -79,16 +123,14 @@ static void early_efi_write_char(u32 *dst, unsigned char c, unsigned int h) } } -static __init void +static void early_efi_write(struct console *con, const char *str, unsigned int num) { struct screen_info *si; - unsigned long base; unsigned int len; const char *s; void *dst; - base = boot_params.screen_info.lfb_base; si = &boot_params.screen_info; len = si->lfb_linelength; @@ -109,7 +151,7 @@ early_efi_write(struct console *con, const char *str, unsigned int num) for (h = 0; h < font->height; h++) { unsigned int n, x; - dst = early_ioremap(base + (efi_y + h) * len, len); + dst = early_efi_map((efi_y + h) * len, len); if (!dst) return; @@ -123,7 +165,7 @@ early_efi_write(struct console *con, const char *str, unsigned int num) s++; } - early_iounmap(dst, len); + early_efi_unmap(dst, len); } num -= count; @@ -179,6 +221,9 @@ static __init int early_efi_setup(struct console *con, char *options) 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; } -- 2.20.1