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Commit 5f35eb0e authored by Dave Young's avatar Dave Young Committed by Matt Fleming
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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: default avatarDave Young <dyoung@redhat.com>
Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
parent 47514c99

arch/x86/platform/efi/early_printk.c

+64 −19
Original line number Diff line number Diff line
@@ -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);

}



static __init_refok void early_efi_unmap(void *addr, unsigned long len)

{

	if (!efi_fb)

		early_iounmap(addr, len);

}



	dst = early_ioremap(base + y*len, 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;

}