From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 9843D3D68; Thu, 6 Mar 2025 09:22:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741252970; cv=none; b=cOH5jtZCPDmnUwjy3I+jHSa6BxdiEJjIDXZ8Bn2EqeXsirPggIw0Y6Vu5LNzrKaGjVGuP3JtnanfltXpzfziTb2qXKZ7ULTkg8yfNqH7QGqW6Wt5aFUg2SYo83zIjNhdy5ByFQi3WFtNLUCO4pPTx7D52No+o0SpC9fawRUqjIw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741252970; c=relaxed/simple; bh=IdoNQjVtAHqJey1aYxsMjH24LlhppEYBJRnQo0p6aUA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fi8yYazca7UrrHeZpcY1xBbIKW5PdgwyqH+cgqY+oum0jxVIHl8gFiLf+h1BCrtncp1qc1UH+usJpDNmMrbV2SejgIUA1CnGqYop6ozD+y6XGGHtD32BiF4BHJHKFV+l8wMlHQF3HcwbM6eh6ZgIa0JOewV9jLbhan9feWQ5CAs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AF1E4FEC; Thu, 6 Mar 2025 01:22:59 -0800 (PST) Received: from [10.57.83.26] (unknown [10.57.83.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8E1DF3F673; Thu, 6 Mar 2025 01:22:45 -0800 (PST) Message-ID: <9a9bdf37-1462-4aca-b513-268b4f2b235c@arm.com> Date: Thu, 6 Mar 2025 09:22:43 +0000 Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 1/3] PM: EM: Consify two parameters of em_dev_register_perf_domain() To: "Rafael J. Wysocki" Cc: LKML , Dietmar Eggemann , Ricardo Neri , Linux PM References: <5880743.DvuYhMxLoT@rjwysocki.net> <4648962.LvFx2qVVIh@rjwysocki.net> Content-Language: en-US From: Lukasz Luba In-Reply-To: <4648962.LvFx2qVVIh@rjwysocki.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 3/5/25 21:08, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Notice that em_dev_register_perf_domain() and the functions called by it > do not update objects pointed to by its cb and cpus parameters, so the > const modifier can be added to them. > > This allows the return value of cpumask_of() or a pointer to a > struct em_data_callback declared as const to be passed to > em_dev_register_perf_domain() directly without explicit type > casting which is rather handy. > > No intentional functional impact. > > Signed-off-by: Rafael J. Wysocki > --- > include/linux/energy_model.h | 8 ++++---- > kernel/power/energy_model.c | 11 ++++++----- > 2 files changed, 10 insertions(+), 9 deletions(-) > > --- a/include/linux/energy_model.h > +++ b/include/linux/energy_model.h > @@ -169,8 +169,8 @@ > int em_dev_update_perf_domain(struct device *dev, > struct em_perf_table __rcu *new_table); > int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, > - struct em_data_callback *cb, cpumask_t *span, > - bool microwatts); > + const struct em_data_callback *cb, > + const cpumask_t *cpus, bool microwatts); > void em_dev_unregister_perf_domain(struct device *dev); > struct em_perf_table __rcu *em_table_alloc(struct em_perf_domain *pd); > void em_table_free(struct em_perf_table __rcu *table); > @@ -346,8 +346,8 @@ > > static inline > int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, > - struct em_data_callback *cb, cpumask_t *span, > - bool microwatts) > + const struct em_data_callback *cb, > + const cpumask_t *cpus, bool microwatts) > { > return -EINVAL; > } > --- a/kernel/power/energy_model.c > +++ b/kernel/power/energy_model.c > @@ -231,7 +231,7 @@ > } > > static int em_compute_costs(struct device *dev, struct em_perf_state *table, > - struct em_data_callback *cb, int nr_states, > + const struct em_data_callback *cb, int nr_states, > unsigned long flags) > { > unsigned long prev_cost = ULONG_MAX; > @@ -333,7 +333,7 @@ > > static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd, > struct em_perf_state *table, > - struct em_data_callback *cb, > + const struct em_data_callback *cb, > unsigned long flags) > { > unsigned long power, freq, prev_freq = 0; > @@ -388,7 +388,8 @@ > } > > static int em_create_pd(struct device *dev, int nr_states, > - struct em_data_callback *cb, cpumask_t *cpus, > + const struct em_data_callback *cb, > + const cpumask_t *cpus, > unsigned long flags) > { > struct em_perf_table __rcu *em_table; > @@ -548,8 +549,8 @@ > * Return 0 on success > */ > int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, > - struct em_data_callback *cb, cpumask_t *cpus, > - bool microwatts) > + const struct em_data_callback *cb, > + const cpumask_t *cpus, bool microwatts) > { > unsigned long cap, prev_cap = 0; > unsigned long flags = 0; > > > LGTM, Reviewed-by: Lukasz Luba