linux-kernel - Re: [PATCH v2 2/4] zynq: move static peripheral mappings

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <201210231450.11540.arnd@arndb.de>
Date:	Tue, 23 Oct 2012 14:50:11 +0000
From:	Arnd Bergmann <arnd@...db.de>
To:	Josh Cartwright <josh.cartwright@...com>
Cc:	arm@...nel.org, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org, John Linn <john.linn@...inx.com>
Subject: Re: [PATCH v2 2/4] zynq: move static peripheral mappings

On Monday 22 October 2012, Josh Cartwright wrote:
> Shifting them up into the vmalloc region prevents the following warning,
> when booting a zynq qemu target with more than 512mb of RAM:
> 
>   BUG: mapping for 0xe0000000 at 0xe0000000 out of vmalloc space
> 
> In addition, it allows for reuse of these mappings when the proper
> drivers issue requests via ioremap().
> 
> Signed-off-by: Josh Cartwright <josh.cartwright@...com>

This looks like a bug fix that should be backported to older kernels,
so it would be good to add 'Cc: stable@...r.kernel.org' below your
Signed-off-by.


> diff --git a/arch/arm/mach-zynq/include/mach/zynq_soc.h b/arch/arm/mach-zynq/include/mach/zynq_soc.h
> index d0d3f8f..ae3b236 100644
> --- a/arch/arm/mach-zynq/include/mach/zynq_soc.h
> +++ b/arch/arm/mach-zynq/include/mach/zynq_soc.h
> @@ -15,33 +15,37 @@
>  #ifndef __MACH_XILINX_SOC_H__
>  #define __MACH_XILINX_SOC_H__
>  
> +#include <asm/pgtable.h>
> +
>  #define PERIPHERAL_CLOCK_RATE		2500000
>  
> -/* For now, all mappings are flat (physical = virtual)
> +/* Static peripheral mappings are mapped at the top of the
> + * vmalloc region
>   */
> -#define UART0_PHYS			0xE0000000
> -#define UART0_VIRT			UART0_PHYS
> +#define UART0_PHYS		0xE0000000
> +#define UART0_SIZE		SZ_4K
> +#define UART0_VIRT		(VMALLOC_END - UART0_SIZE)

There are plans to move the uart location into a fixed virtual
address in the future, but it hasn't been decided yet.
It will still need a fixed mapping though, just to a different
address.

> -#define TTC0_PHYS			0xF8001000
> -#define TTC0_VIRT			TTC0_PHYS
> +#define TTC0_PHYS		0xF8001000
> +#define TTC0_SIZE		SZ_4K
> +#define TTC0_VIRT		(UART0_VIRT - TTC0_SIZE)

It's quite likely that this does not have to be a fixed mapping
any more. Just have a look at how drivers/clocksource/dw_apb_timer_of.c
calls of_iomap() to get the address.

> -#define PL310_L2CC_PHYS			0xF8F02000
> -#define PL310_L2CC_VIRT			PL310_L2CC_PHYS
> +#define PL310_L2CC_PHYS		0xF8F02000
> +#define PL310_L2CC_SIZE		SZ_4K
> +#define PL310_L2CC_VIRT		(TTC0_VIRT - PL310_L2CC_SIZE)

This address would not need a fixed mapping by calling l2x0_of_init
rather than l2x0_init.

> -#define SCU_PERIPH_PHYS			0xF8F00000
> -#define SCU_PERIPH_VIRT			SCU_PERIPH_PHYS
> +#define SCU_PERIPH_PHYS		0xF8F00000
> +#define SCU_PERIPH_SIZE		SZ_8K
> +#define SCU_PERIPH_VIRT		(PL310_L2CC_VIRT - SCU_PERIPH_SIZE)

And your patch 3 already obsoletes this mapping.

	Arnd
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/