[PATCH] Fix vgacon oops on 64-bit

[PATCH] Fix vgacon oops on 64-bit

[Matt Porter]

Although I'm not running a VGA card, I noticed this building
a working malta 32-bit defconfig (vgacon enabled) for 64-bit.
Without it, the vgacon probe will access unmapped space when
looking to see if a vga card is present.

Signed-off-by: Matt Porter <mporter@kernel.crashing.org>

diff --git a/include/asm-mips/vga.h b/include/asm-mips/vga.h
index ca5cec9..1390ab6 100644
--- a/include/asm-mips/vga.h
+++ b/include/asm-mips/vga.h
@@ -13,7 +13,11 @@
  *	access the videoram directly without any black magic.
  */
 
+#ifdef CONFIG_64BIT
+#define VGA_MAP_MEM(x)	(0xffffffffb0000000UL + (unsigned long)(x))
+#else
 #define VGA_MAP_MEM(x)	(0xb0000000L + (unsigned long)(x))
+#endif
 
 #define vga_readb(x)	(*(x))
 #define vga_writeb(x,y)	(*(y) = (x))

Re: [PATCH] Fix vgacon oops on 64-bit

[Ralf Baechle]

On Mon, Jan 30, 2006 at 08:33:21AM -0700, Matt Porter wrote:

> Although I'm not running a VGA card, I noticed this building
> a working malta 32-bit defconfig (vgacon enabled) for 64-bit.
> Without it, the vgacon probe will access unmapped space when
> looking to see if a vga card is present.
> 
> Signed-off-by: Matt Porter <mporter@kernel.crashing.org>
> 
> diff --git a/include/asm-mips/vga.h b/include/asm-mips/vga.h
> index ca5cec9..1390ab6 100644
> --- a/include/asm-mips/vga.h
> +++ b/include/asm-mips/vga.h
> @@ -13,7 +13,11 @@
>   *	access the videoram directly without any black magic.
>   */
>  
> +#ifdef CONFIG_64BIT
> +#define VGA_MAP_MEM(x)	(0xffffffffb0000000UL + (unsigned long)(x))
> +#else
>  #define VGA_MAP_MEM(x)	(0xb0000000L + (unsigned long)(x))
> +#endif

Looks like driving out the devil with beelzebub.  The 0xb0000000 address
is totally platform specific and nobody ever noticed ...

  Ralf

Re: [PATCH] Fix vgacon oops on 64-bit

[Matt Porter]

On Mon, Jan 30, 2006 at 06:17:54PM +0000, Ralf Baechle wrote:
> On Mon, Jan 30, 2006 at 08:33:21AM -0700, Matt Porter wrote:
> > +#ifdef CONFIG_64BIT
> > +#define VGA_MAP_MEM(x)	(0xffffffffb0000000UL + (unsigned long)(x))
> > +#else
> >  #define VGA_MAP_MEM(x)	(0xb0000000L + (unsigned long)(x))
> > +#endif
> 
> Looks like driving out the devil with beelzebub.  The 0xb0000000 address
> is totally platform specific and nobody ever noticed ...

Ok, added a platform dependent hook that the setup code can
configure appropriately.

Signed-off-by: Matt Porter <mporter@kernel.crashing.org>

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index d86affa..5e01f53 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -51,6 +51,10 @@ EXPORT_SYMBOL(cpu_data);
 struct screen_info screen_info;
 #endif
 
+#ifdef CONFIG_VGA_CONSOLE
+unsigned long vgacon_remap_base;
+#endif
+
 /*
  * Despite it's name this variable is even if we don't have PCI
  */
diff --git a/arch/mips/mips-boards/malta/malta_setup.c b/arch/mips/mips-boards/malta/malta_setup.c
index 2209e8a..b344095 100644
--- a/arch/mips/mips-boards/malta/malta_setup.c
+++ b/arch/mips/mips-boards/malta/malta_setup.c
@@ -42,6 +42,9 @@
 #ifdef CONFIG_VT
 #include <linux/console.h>
 #endif
+#ifdef CONFIG_VGA_CONSOLE
+#include <asm/vga.h>
+#endif
 
 extern void mips_reboot_setup(void);
 extern void mips_time_init(void);
@@ -210,6 +213,12 @@ void __init plat_setup(void)
 		VIDEO_TYPE_VGAC,	/* orig-video-isVGA */
 		16			/* orig-video-points */
 	};
+
+#ifdef CONFIG_64BIT
+	vgacon_remap_base = 0xffffffffb0000000;
+#else
+	vgacon_remap_base = 0xb0000000;
+#endif
 #endif
 #endif
 
diff --git a/include/asm-mips/vga.h b/include/asm-mips/vga.h
index ca5cec9..2bedca2 100644
--- a/include/asm-mips/vga.h
+++ b/include/asm-mips/vga.h
@@ -13,7 +13,9 @@
  *	access the videoram directly without any black magic.
  */
 
-#define VGA_MAP_MEM(x)	(0xb0000000L + (unsigned long)(x))
+extern unsigned long vgacon_remap_base;
+
+#define VGA_MAP_MEM(x)	(vgacon_remap_base + (unsigned long)(x))
 
 #define vga_readb(x)	(*(x))
 #define vga_writeb(x,y)	(*(y) = (x))