Re: [PATCH] ARM: pxa: Move iotable mapping inside vmalloc region

Nicolas Pitre
2013-11-24T23:26:49Z

On Sun, 24 Nov 2013, Ezequiel Garcia wrote:

> In order to remove the following ugly message:
>
> BUG: mapping for 0x00000000 at 0xff000000 out of vmalloc space
>
> the iotable mappings should be re-located inside the vmalloc
> region. Such move was introduced at commit:
>
> commit 0536bdf33faff4d940ac094c77998cfac368cfff
> Author: Nicolas Pitre <nicolas.pitre@linaro.org>
> Date: Thu Aug 25 00:35:59 2011 -0400
>
> ARM: move iotable mappings within the vmalloc region
>
> While at it, let's add some nicer defines to make the code
> more readable.
>
> Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> ---
> arch/arm/mach-pxa/generic.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm/mach-pxa/generic.c b/arch/arm/mach-pxa/generic.c
> index 4225417..7c01095 100644
> --- a/arch/arm/mach-pxa/generic.c
> +++ b/arch/arm/mach-pxa/generic.c
> @@ -24,6 +24,7 @@
> #include <mach/hardware.h>
> #include <asm/mach/map.h>
> #include <asm/mach-types.h>
> +#include <asm/pgtable.h>
>
> #include <mach/reset.h>
> #include <mach/smemc.h>
> @@ -77,6 +78,11 @@ EXPORT_SYMBOL(get_clk_frequency_khz);
> * Note: virtual 0xfffe0000-0xffffffff is reserved for the vector table
> * and cache flush area.
> */
> +
> +#define UNCACHED_PHY 0x00000000
> +#define UNCACHED_SIZE SZ_1M
> +#define UNCACHED_VIRT (VMALLOC_END - UNCACHED_SIZE)
> +
> static struct map_desc common_io_desc[] __initdata = {
> { /* Devs */
> .virtual = 0xf2000000,
> @@ -84,9 +90,9 @@ static struct map_desc common_io_desc[] __initdata = {
> .length = 0x02000000,
> .type = MT_DEVICE
> }, { /* UNCACHED_PHYS_0 */
> - .virtual = 0xff000000,
> - .pfn = __phys_to_pfn(0x00000000),
> - .length = 0x00100000,
> + .virtual = UNCACHED_VIRT,
> + .pfn = __phys_to_pfn(UNCACHED_PHY),
> + .length = UNCACHED_SIZE,
> .type = MT_DEVICE
> }
> };

You might wish to change the virtual address for this mapping, but
nowhere in your patch you are changing users of that virtual mapping.

Nicolas