Re: [PATCH] mmuinfo: add a command do display the result of virtual to physical translation

[Sascha Hauer <s.hauer@pengutronix.de>]

On Thu, Jun 21, 2012 at 06:04:44PM +0200, Jan Luebbe wrote:
> Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
> ---
>  arch/arm/Kconfig       |   10 ++++-
>  arch/arm/cpu/Makefile  |    1 +
>  arch/arm/cpu/mmuinfo.c |  107 ++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 117 insertions(+), 1 deletion(-)
>  create mode 100644 arch/arm/cpu/mmuinfo.c
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 8a4e1a2..2f35738 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -123,7 +123,15 @@ config CMD_ARM_CPUINFO
>  	default y
>  	help
>  	  Say yes here to get a cpuinfo command to show some
> -	  information about the cp15 registers
> +	  CPU information using the cp15 registers
> +
> +config CMD_ARM_MMUINFO
> +	bool "mmuinfo command"
> +	depends on CPU_V7
> +	default n
> +	help
> +	  Say yes here to get a mmuinfo command to show some
> +	  MMU and cache information using the cp15 registers
>  
>  config CPU_V7_DCACHE_SKIP
>  	bool "Skip DCache Invalidate"
> diff --git a/arch/arm/cpu/Makefile b/arch/arm/cpu/Makefile
> index e30ae1c..93a34a9 100644
> --- a/arch/arm/cpu/Makefile
> +++ b/arch/arm/cpu/Makefile
> @@ -7,6 +7,7 @@ obj-y += start.o
>  # Any variants can be called as start-armxyz.S
>  #
>  obj-$(CONFIG_CMD_ARM_CPUINFO) += cpuinfo.o
> +obj-$(CONFIG_CMD_ARM_MMUINFO) += mmuinfo.o
>  obj-$(CONFIG_MMU) += mmu.o
>  obj-$(CONFIG_CPU_32v4T) += cache-armv4.o
>  obj-$(CONFIG_CPU_32v5) += cache-armv5.o
> diff --git a/arch/arm/cpu/mmuinfo.c b/arch/arm/cpu/mmuinfo.c
> new file mode 100644
> index 0000000..6177785
> --- /dev/null
> +++ b/arch/arm/cpu/mmuinfo.c
> @@ -0,0 +1,107 @@
> +/*
> + * mmuinfo.c - Show MMU/cache information from cp15 registers
> + *
> + * Copyright (c) Jan Luebbe <j.luebbe@pengutronix.de>, Pengutronix
> + *
> + * See file CREDITS for list of people who contributed to this
> + * project.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
> + */
> +
> +#include <common.h>
> +#include <command.h>
> +
> +static char *inner_attr[] = {
> +	"0b000 Non-cacheable",
> +	"0b001 Strongly-ordered",
> +	"0b010 (reserved)",
> +	"0b011 Device",
> +	"0b100 (reserved)",
> +	"0b101 Write-Back, Write-Allocate",
> +	"0b110 Write-Through",
> +	"0b111 Write-Back, no Write-Allocate",
> +};
> +
> +static char *outer_attr[] = {
> +	"0b00 Non-cacheable",
> +	"0b01 Write-Back, Write-Allocate",
> +	"0b10 Write-Through, no Write-Allocate",
> +	"0b11 Write-Back, no Write-Allocate",
> +};
> +
> +static void decode_par(unsigned long par)
> +{
> +	printf("  Physical Address [31:12]: 0x%08lx\n", par & 0xFFFFF000);
> +	printf("  Reserved [11]:            0x%lx\n", (par >> 11) & 0x1);
> +	printf("  Not Outer Shareable [10]: 0x%lx\n", (par >> 10) & 0x1);
> +	printf("  Non-Secure [9]:           0x%lx\n", (par >> 9) & 0x1);
> +	printf("  Impl. def. [8]:           0x%lx\n", (par >> 8) & 0x1);
> +	printf("  Shareable [7]:            0x%lx\n", (par >> 7) & 0x1);
> +	printf("  Inner mem. attr. [6:4]:   0x%lx (%s)\n", (par >> 4) & 0x7,
> +		inner_attr[(par >> 4) & 0x7]);
> +	printf("  Outer mem. attr. [3:2]:   0x%lx (%s)\n", (par >> 2) & 0x3,
> +		outer_attr[(par >> 2) & 0x3]);
> +	printf("  SuperSection [1]:         0x%lx\n", (par >> 1) & 0x1);
> +	printf("  Failure [0]:              0x%lx\n", (par >> 0) & 0x1);
> +}
> +
> +static int do_mmuinfo(int argc, char *argv[])
> +{
> +	unsigned long addr = 0, priv_read, priv_write;
> +
> +	if (argc < 2)
> +		return 1;

return COMMAND_ERROR_USAGE here.

> +
> +	addr = strtoul_suffix(argv[1], NULL, 0);
> +
> +	__asm__ __volatile__(
> +		"mcr    p15, 0, %0, c7, c8, 0   @ write VA to PA translation (priv read)\n"
> +		:
> +		: "r" (addr)
> +		: "memory");
> +
> +	__asm__ __volatile__(
> +		"mrc    p15, 0, %0, c7, c4, 0   @ read PAR\n"
> +		: "=r" (priv_read)
> +		:
> +		: "memory");
> +
> +
> +	__asm__ __volatile__(
> +		"mcr    p15, 0, %0, c7, c8, 1   @ write VA to PA translation (priv write)\n"
> +		:
> +		: "r" (addr)
> +		: "memory");
> +
> +	__asm__ __volatile__(
> +		"mrc    p15, 0, %0, c7, c4, 0   @ read PAR\n"
> +		: "=r" (priv_write)
> +		:
> +		: "memory");
> +
> +	printf("PAR result for 0x%08lx: \n", addr);
> +	printf(" privileged read: 0x%08lx\n", priv_read);
> +	decode_par(priv_read);
> +	printf(" privileged write: 0x%08lx\n", priv_write);
> +	decode_par(priv_write);
> +
> +	return 0;
> +}
> +
> +BAREBOX_CMD_START(mmuinfo)
> +	.cmd            = do_mmuinfo,
> +	.usage          = "Show info about MMU",
> +BAREBOX_CMD_END

Some usage information would be nice, "mmuinfo <address>" should be
sufficient.

> +

No newline at end of file please.

Otherwise, nice debug utility :)

Sascha


-- 
Pengutronix e.K.                           |                             |
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