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Reply-To: Gavin Shan <gshan@redhat.com>
Subject: Re: [PATCH v3 01/16] cacheinfo: Use of_cpu_device_node_get instead
 cpu_dev->of_node
To:     Sudeep Holla <sudeep.holla@arm.com>, linux-kernel@vger.kernel.org
Cc:     Atish Patra <atishp@atishpatra.org>,
        Atish Patra <atishp@rivosinc.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Morten Rasmussen <morten.rasmussen@arm.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Qing Wang <wangqing@vivo.com>,
        linux-arm-kernel@lists.infradead.org,
        linux-riscv@lists.infradead.org, Rob Herring <robh+dt@kernel.org>
References: <20220525081416.3306043-1-sudeep.holla@arm.com>
 <20220525081416.3306043-2-sudeep.holla@arm.com>
From:   Gavin Shan <gshan@redhat.com>
Message-ID: <42bb2efe-e28c-fd15-d00e-8f45dc24b0d1@redhat.com>
Date:   Wed, 1 Jun 2022 10:45:00 +0800
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On 5/25/22 4:14 PM, Sudeep Holla wrote:
> The of_cpu_device_node_get takes care of fetching the CPU'd device node
> either from cached cpu_dev->of_node if cpu_dev is initialised or uses
> of_get_cpu_node to parse and fetch node if cpu_dev isn't available yet.
> 
> Just use of_cpu_device_node_get instead of getting the cpu device first
> and then using cpu_dev->of_node for two reasons:
> 1. There is no other use of cpu_dev and can be simplified
> 2. It enabled the use detect_cache_attributes and hence cache_setup_of_node
>     much earlier before the CPUs are registered as devices.
> 
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
>   drivers/base/cacheinfo.c | 9 ++-------
>   1 file changed, 2 insertions(+), 7 deletions(-)
> 

Reviewed-by: Gavin Shan <gshan@redhat.com>

> diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
> index dad296229161..b0bde272e2ae 100644
> --- a/drivers/base/cacheinfo.c
> +++ b/drivers/base/cacheinfo.c
> @@ -14,7 +14,7 @@
>   #include <linux/cpu.h>
>   #include <linux/device.h>
>   #include <linux/init.h>
> -#include <linux/of.h>
> +#include <linux/of_device.h>
>   #include <linux/sched.h>
>   #include <linux/slab.h>
>   #include <linux/smp.h>
> @@ -157,7 +157,6 @@ static int cache_setup_of_node(unsigned int cpu)
>   {
>   	struct device_node *np;
>   	struct cacheinfo *this_leaf;
> -	struct device *cpu_dev = get_cpu_device(cpu);
>   	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
>   	unsigned int index = 0;
>   
> @@ -166,11 +165,7 @@ static int cache_setup_of_node(unsigned int cpu)
>   		return 0;
>   	}
>   
> -	if (!cpu_dev) {
> -		pr_err("No cpu device for CPU %d\n", cpu);
> -		return -ENODEV;
> -	}
> -	np = cpu_dev->of_node;
> +	np = of_cpu_device_node_get(cpu);
>   	if (!np) {
>   		pr_err("Failed to find cpu%d device node\n", cpu);
>   		return -ENOENT;
>