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From: Oliver Upton <oupton@google.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Marc Zyngier <maz@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Ricardo Koller <ricarkol@google.com>,
	Reiji Watanabe <reijiw@google.com>
Subject: Re: [boot-wrapper PATCH] configure: Allow user to specify the counter frequency
Date: Wed, 16 Mar 2022 04:56:40 +0000	[thread overview]
Message-ID: <YjFuCN2za7ZGJRUl@google.com> (raw)
In-Reply-To: <20220224044947.980030-1-oupton@google.com>

On Thu, Feb 24, 2022 at 04:49:47AM +0000, Oliver Upton wrote:
> The default counter frequency on certain models is not actually 24MHz.
> For example, on the FVP Base RevC model, the default counter frequency
> is 100MHz, and is user configurable. Users testing against an ARMv8.6
> counter (1GHz) also need to override the default value.
> 
> Add an optional configuration option which allows users to specify the
> counter frequency.
> 
> Signed-off-by: Oliver Upton <oupton@google.com>
> ---
>  Makefile.am  | 1 -
>  configure.ac | 8 ++++++++
>  2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/Makefile.am b/Makefile.am
> index 08e304a..c71c601 100644
> --- a/Makefile.am
> +++ b/Makefile.am
> @@ -13,7 +13,6 @@ SCRIPT_DIR	:= $(top_srcdir)/scripts
>  PHYS_OFFSET	:= $(shell perl -I $(SCRIPT_DIR) $(SCRIPT_DIR)/findmem.pl $(KERNEL_DTB))
>  UART_BASE	:= $(shell perl -I $(SCRIPT_DIR) $(SCRIPT_DIR)/findbase.pl $(KERNEL_DTB) 0 'arm,pl011')
>  SYSREGS_BASE	:= $(shell perl -I $(SCRIPT_DIR) $(SCRIPT_DIR)/findbase.pl $(KERNEL_DTB) 0 'arm,vexpress-sysreg' 2> /dev/null)
> -COUNTER_FREQ	:= 24000000
>  
>  CPU_IDS		:= $(shell perl -I $(SCRIPT_DIR) $(SCRIPT_DIR)/findcpuids.pl $(KERNEL_DTB))
>  NR_CPUS         := $(shell echo $(CPU_IDS) | tr ',' ' ' | wc -w)
> diff --git a/configure.ac b/configure.ac
> index 9e3b722..e7d086a 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -118,6 +118,13 @@ AC_ARG_ENABLE([gicv3],
>  AM_CONDITIONAL([GICV3], [test "x$USE_GICV3" = "xyes"])
>  AS_IF([test "x$USE_GICV3" = "xyes"], [], [USE_GICV3=no])
>  
> +# Allow a user to set the exposed counter frequency
> +C_COUNTER_FREQ=24000000
> +AC_ARG_WITH([counter-frequency],
> +            AS_HELP_STRING([--with-counter-frequency], [set counter frequency (in Hz)]),
> +            [C_COUNTER_FREQ=$withval])
> +AC_SUBST([COUNTER_FREQ], [$C_COUNTER_FREQ])
> +
>  # Ensure that we have all the needed programs
>  AC_PROG_CC
>  AC_PROG_CPP
> @@ -151,4 +158,5 @@ echo "  Xen image                          ${XEN_IMAGE:-NONE}"
>  if test "x${XEN_IMAGE}" != "x"; then
>  echo "  Xen command line:                  ${XEN_CMDLINE}"
>  fi
> +echo "  Counter frequency (Hz)             ${COUNTER_FREQ}"
>  echo ""
> -- 
> 2.35.1.473.g83b2b277ed-goog
> 

Friendly ping :)

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      reply	other threads:[~2022-03-16  4:58 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-24  4:49 [boot-wrapper PATCH] configure: Allow user to specify the counter frequency Oliver Upton
2022-03-16  4:56 ` Oliver Upton [this message]

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