From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
To: Lucas Stach <l.stach@pengutronix.de>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH 2/3] ARM: correctly identify ARMv6 K/Z
Date: Wed, 1 Mar 2017 18:55:38 +0100 [thread overview]
Message-ID: <20170301175538.GC4120@mail.ovh.net> (raw)
In-Reply-To: <20170301142641.6596-2-l.stach@pengutronix.de>
On 15:26 Wed 01 Mar , Lucas Stach wrote:
> The ARMv6 K/Z derivatives have a v7 compatible MMU, but all other parts
> (including the cache handling) is still at v6. As we don't make use of
> the more advanced features of the v7 MMU in Barebox, it's okay to just
> override this to properly identify the CPU as ARMv6.
evenif we do not use it now I do not liek the idea to report it as ARMv6
It will be better to report it correctly
Best Regards,
J.
>
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> ---
> arch/arm/cpu/cpuinfo.c | 8 ++++++++
> arch/arm/include/asm/system_info.h | 8 ++++++++
> 2 files changed, 16 insertions(+)
>
> diff --git a/arch/arm/cpu/cpuinfo.c b/arch/arm/cpu/cpuinfo.c
> index 86e19d9780d5..175475b038dc 100644
> --- a/arch/arm/cpu/cpuinfo.c
> +++ b/arch/arm/cpu/cpuinfo.c
> @@ -165,6 +165,14 @@ static int do_cpuinfo(int argc, char *argv[])
> } else
> cpu_arch = CPU_ARCH_UNKNOWN;
>
> + /*
> + * Special case for ARMv6 (K/Z) (has v7 compatible MMU, but is v6
> + * otherwise). The below check just matches all ARMv6, as done in the
> + * Linux kernel.
> + */
> + if ((mainid & 0x7f000) == 0x7b000)
> + cpu_arch = CPU_ARCH_ARMv6;
> +
> switch (cpu_arch) {
> case CPU_ARCH_ARMv3:
> architecture = "v3";
> diff --git a/arch/arm/include/asm/system_info.h b/arch/arm/include/asm/system_info.h
> index 25fffd268177..a27b79e6dd08 100644
> --- a/arch/arm/include/asm/system_info.h
> +++ b/arch/arm/include/asm/system_info.h
> @@ -188,6 +188,14 @@ static inline int arm_early_get_cpu_architecture(void)
> cpu_arch = CPU_ARCH_UNKNOWN;
> #endif
>
> + /*
> + * Special case for ARMv6 (K/Z) (has v7 compatible MMU, but is v6
> + * otherwise). The below check just matches all ARMv6, as done in the
> + * Linux kernel.
> + */
> + if ((read_cpuid_id() & 0x7f000) == 0x7b000)
> + cpu_arch = CPU_ARCH_ARMv6;
> +
> return cpu_arch;
> }
>
> --
> 2.11.0
>
>
> _______________________________________________
> barebox mailing list
> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox
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next prev parent reply other threads:[~2017-03-01 17:49 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-01 14:26 [PATCH 1/3] ARM: align exception vectors to 32 byte Lucas Stach
2017-03-01 14:26 ` [PATCH 2/3] ARM: correctly identify ARMv6 K/Z Lucas Stach
2017-03-01 17:55 ` Jean-Christophe PLAGNIOL-VILLARD [this message]
2017-03-02 10:42 ` Lucas Stach
2017-03-03 6:04 ` Sascha Hauer
2017-03-03 14:26 ` Jean-Christophe PLAGNIOL-VILLARD
2017-03-01 14:26 ` [PATCH 3/3] ARM: execute DMB before trying to flush cache Lucas Stach
2017-03-02 8:08 ` [PATCH 1/3] ARM: align exception vectors to 32 byte Uwe Kleine-König
2017-03-03 6:06 ` Sascha Hauer
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