Re: [PATCH v3 1/5] cacheinfo: Use RISC-V's init_cache_level() as generic OF implementation

From: Rob Herring <robh@kernel.org>
To: Pierre Gondois <pierre.gondois@arm.com>
Cc: linux-kernel@vger.kernel.org, palmer@rivosinc.com,
	Ionela.Voinescu@arm.com,
	Conor Dooley <conor.dooley@microchip.com>,
	Sudeep Holla <sudeep.holla@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Len Brown <lenb@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jeremy Linton <jeremy.linton@arm.com>,
	Gavin Shan <gshan@redhat.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-riscv@lists.infradead.org, linux-acpi@vger.kernel.org
Subject: Re: [PATCH v3 1/5] cacheinfo: Use RISC-V's init_cache_level() as generic OF implementation
Date: Tue, 20 Dec 2022 17:39:12 -0600	[thread overview]
Message-ID: <20221220233912.GA1193943-robh@kernel.org> (raw)
In-Reply-To: <20221209103130.572196-2-pierre.gondois@arm.com>

On Fri, Dec 09, 2022 at 11:31:23AM +0100, Pierre Gondois wrote:
> RISC-V's implementation of init_of_cache_level() is following
> the Devicetree Specification v0.3 regarding caches, cf.:
> - s3.7.3 'Internal (L1) Cache Properties'
> - s3.8 'Multi-level and Shared Cache Nodes'
> 
> Allow reusing the implementation by moving it.
> 
> Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
> Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
> ---
>  arch/riscv/kernel/cacheinfo.c | 39 +------------------------------
>  drivers/base/cacheinfo.c      | 44 +++++++++++++++++++++++++++++++++++
>  include/linux/cacheinfo.h     |  1 +
>  3 files changed, 46 insertions(+), 38 deletions(-)
> 
> diff --git a/arch/riscv/kernel/cacheinfo.c b/arch/riscv/kernel/cacheinfo.c
> index 90deabfe63ea..440a3df5944c 100644
> --- a/arch/riscv/kernel/cacheinfo.c
> +++ b/arch/riscv/kernel/cacheinfo.c
> @@ -115,44 +115,7 @@ static void fill_cacheinfo(struct cacheinfo **this_leaf,
>  
>  int init_cache_level(unsigned int cpu)
>  {
> -	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
> -	struct device_node *np = of_cpu_device_node_get(cpu);
> -	struct device_node *prev = NULL;
> -	int levels = 0, leaves = 0, level;
> -
> -	if (of_property_read_bool(np, "cache-size"))
> -		++leaves;
> -	if (of_property_read_bool(np, "i-cache-size"))
> -		++leaves;
> -	if (of_property_read_bool(np, "d-cache-size"))
> -		++leaves;
> -	if (leaves > 0)
> -		levels = 1;
> -
> -	prev = np;
> -	while ((np = of_find_next_cache_node(np))) {
> -		of_node_put(prev);
> -		prev = np;
> -		if (!of_device_is_compatible(np, "cache"))
> -			break;
> -		if (of_property_read_u32(np, "cache-level", &level))
> -			break;
> -		if (level <= levels)
> -			break;
> -		if (of_property_read_bool(np, "cache-size"))
> -			++leaves;
> -		if (of_property_read_bool(np, "i-cache-size"))
> -			++leaves;
> -		if (of_property_read_bool(np, "d-cache-size"))
> -			++leaves;
> -		levels = level;
> -	}
> -
> -	of_node_put(np);
> -	this_cpu_ci->num_levels = levels;
> -	this_cpu_ci->num_leaves = leaves;
> -
> -	return 0;
> +	return init_of_cache_level(cpu);

Not in this patch, but in patch 5, shouldn't riscv init_cache_level() be 
removed? The topology code already called init_of_cache_level() and 
RiscV has nothing architectural to add/change. IOW, init_cache_level() 
should only do architecture defined init, and not anything DT or ACPI 
related (unless those are non-standard).

Rob