linux-kernel - Re: [PATCH v2 4/5] ACPI: PPTT: Update acpi_find_last_cache_level() to acpi_get_cache

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Date:   Fri, 25 Nov 2022 15:18:47 +0000
From:   Sudeep Holla <sudeep.holla@....com>
To:     Pierre Gondois <pierre.gondois@....com>
Cc:     linux-kernel@...r.kernel.org, Ionela.Voinescu@....com,
        Rob.Herring@....com, Jeremy Linton <jeremy.linton@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Sudeep Holla <sudeep.holla@....com>,
        Will Deacon <will@...nel.org>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Len Brown <lenb@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Conor Dooley <conor.dooley@...rochip.com>,
        Gavin Shan <gshan@...hat.com>,
        Peter Chen <peter.chen@...nel.org>,
        SeongJae Park <sj@...nel.org>,
        Jakub Kicinski <kuba@...nel.org>,
        linux-arm-kernel@...ts.infradead.org,
        linux-riscv@...ts.infradead.org, linux-acpi@...r.kernel.org
Subject: Re: [PATCH v2 4/5] ACPI: PPTT: Update acpi_find_last_cache_level()
 to acpi_get_cache_info()

On Mon, Nov 21, 2022 at 06:12:12PM +0100, Pierre Gondois wrote:
> acpi_find_last_cache_level() allows to find the last level of cache
> for a given CPU. The function is only called on arm64 ACPI based
> platforms to check for cache information that would be missing in
> the CLIDR_EL1 register.
> To allow populating (struct cpu_cacheinfo).num_leaves by only parsing
> a PPTT, update acpi_find_last_cache_level() to get the 'split_levels',
> i.e. the number of cache levels being split in data/instruction
> caches.
> 
> It is assumed that there will not be data/instruction caches above a
> unified cache.
> If a split level consist of one data cache and no instruction cache
> (or opposite), then the missing cache will still be populated
> by default with minimal cache information, and maximal cpumask
> (all non-existing caches have the same fw_token).
> 
> Suggested-by: Jeremy Linton <jeremy.linton@....com>
> Signed-off-by: Pierre Gondois <pierre.gondois@....com>
> Reviewed-by: Jeremy Linton <jeremy.linton@....com>
> ---
>  arch/arm64/kernel/cacheinfo.c |  9 +++--
>  drivers/acpi/pptt.c           | 76 +++++++++++++++++++++++------------
>  include/linux/cacheinfo.h     |  8 ++--
>  3 files changed, 61 insertions(+), 32 deletions(-)
> 
> diff --git a/arch/arm64/kernel/cacheinfo.c b/arch/arm64/kernel/cacheinfo.c
> index 97c42be71338..164255651d64 100644
> --- a/arch/arm64/kernel/cacheinfo.c
> +++ b/arch/arm64/kernel/cacheinfo.c
> @@ -46,7 +46,7 @@ static void ci_leaf_init(struct cacheinfo *this_leaf,
>  int init_cache_level(unsigned int cpu)
>  {
>  	unsigned int ctype, level, leaves;
> -	int fw_level;
> +	int fw_level, ret;
>  	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
>  
>  	for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) {
> @@ -61,8 +61,11 @@ int init_cache_level(unsigned int cpu)
>  
>  	if (acpi_disabled)
>  		fw_level = of_find_last_cache_level(cpu);
> -	else
> -		fw_level = acpi_find_last_cache_level(cpu);
> +	else {

You need to add braces to if as well in such cases. I think checkpatch
might tell you that. Just found this by chance.

Anyways, this looks good to me.

Reviewed-by: Sudeep Holla <sudeep.holla@....com>


-- 
Regards,
Sudeep