From: Ulf Hansson <ulf.hansson@linaro.org>
To: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net>,
Sudeep Holla <sudeep.holla@arm.com>,
Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Lina Iyer <ilina@codeaurora.org>,
Linux PM <linux-pm@vger.kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
linux-arm-msm <linux-arm-msm@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 5/7] drivers: firmware: psci: Simplify state node parsing
Date: Thu, 28 Feb 2019 23:26:41 +0100 [thread overview]
Message-ID: <CAPDyKFrdwkERTGOkfjCZv-cb0sTvDqtNWY6kKyaeWLHSumRp1A@mail.gmail.com> (raw)
In-Reply-To: <a66689f2-51ba-6358-f161-66778daa1f09@linaro.org>
On Thu, 28 Feb 2019 at 16:40, Daniel Lezcano <daniel.lezcano@linaro.org> wrote:
>
> On 28/02/2019 14:59, Ulf Hansson wrote:
> > Instead of iterating through all the state nodes in DT, to find out how
> > many states that needs to be allocated, let's use the number already known
> > by the cpuidle driver. In this way we can drop the iteration altogether.
> >
> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> > ---
> > drivers/firmware/psci/psci.c | 25 ++++++++++++-------------
> > 1 file changed, 12 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
> > index d50b46a0528f..cbfc936d251c 100644
> > --- a/drivers/firmware/psci/psci.c
> > +++ b/drivers/firmware/psci/psci.c
> > @@ -290,26 +290,20 @@ static int psci_dt_parse_state_node(struct device_node *np, u32 *state)
> > static int psci_dt_cpu_init_idle(struct cpuidle_driver *drv,
> > struct device_node *cpu_node, int cpu)
> > {
> > - int i, ret = 0, count = 0;
> > + int i, ret = 0, num_state_nodes = drv->state_count - 1;
>
> why -1 ?
Because of the WFI state. The cpuidle-arm driver always carries this
state at index 0, which also is never used in
psci_cpu_suspend_enter(), where the similar is taken into account.
It's a bit of magic, so perhaps someone should post a patch that
documents this a bit better in the code, wherever it makes sense.
>
> > u32 *psci_states;
> > struct device_node *state_node;
> >
> > - /* Count idle states */
> > - while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
> > - count))) {
> > - count++;
> > - of_node_put(state_node);
> > - }
> > -
> > - if (!count)
> > - return -ENODEV;
> > -
> > - psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
> > + psci_states = kcalloc(num_state_nodes, sizeof(*psci_states),
> > + GFP_KERNEL);
> > if (!psci_states)
> > return -ENOMEM;
> >
> > - for (i = 0; i < count; i++) {
> > + for (i = 0; i < num_state_nodes; i++) {
> > state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
> > + if (!state_node)
> > + break;
> > +
> > ret = psci_dt_parse_state_node(state_node, &psci_states[i]);
> > of_node_put(state_node);
> >
> > @@ -319,6 +313,11 @@ static int psci_dt_cpu_init_idle(struct cpuidle_driver *drv,
> > pr_debug("psci-power-state %#x index %d\n", psci_states[i], i);
> > }
> >
> > + if (i != num_state_nodes) {
> > + ret = -ENODEV;
> > + goto free_mem;
> > + }
> > +
> > /* Idle states parsed correctly, initialize per-cpu pointer */
> > per_cpu(psci_power_state, cpu) = psci_states;
> > return 0;
> >
Again, thanks a lot for reviewing!
Kind regards
Uffe
next prev parent reply other threads:[~2019-02-28 22:27 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-28 13:59 [PATCH 0/7] drivers: firmware: psci: Some cleanup and refactoring Ulf Hansson
2019-02-28 13:59 ` [PATCH 1/7] drivers: firmware: psci: Move psci to separate directory Ulf Hansson
2019-02-28 14:34 ` Daniel Lezcano
2019-03-01 17:03 ` Mark Rutland
2019-02-28 13:59 ` [PATCH 2/7] MAINTAINERS: Update files for PSCI Ulf Hansson
2019-02-28 14:35 ` Daniel Lezcano
2019-03-01 17:04 ` Mark Rutland
2019-02-28 13:59 ` [PATCH 3/7] drivers: firmware: psci: Split psci_dt_cpu_init_idle() Ulf Hansson
2019-02-28 14:42 ` Daniel Lezcano
2019-02-28 22:13 ` Ulf Hansson
2019-03-01 17:07 ` Mark Rutland
2019-02-28 13:59 ` [PATCH 4/7] ARM/ARM64: cpuidle: Let back-end init ops take the driver as input Ulf Hansson
2019-02-28 15:30 ` Daniel Lezcano
2019-03-01 17:31 ` Mark Rutland
2019-02-28 13:59 ` [PATCH 5/7] drivers: firmware: psci: Simplify state node parsing Ulf Hansson
2019-02-28 15:40 ` Daniel Lezcano
2019-02-28 22:26 ` Ulf Hansson [this message]
2019-02-28 22:41 ` Daniel Lezcano
2019-03-01 17:28 ` Mark Rutland
2019-03-04 10:14 ` Ulf Hansson
2019-03-06 18:15 ` Lorenzo Pieralisi
2019-03-08 10:36 ` Ulf Hansson
2019-03-08 11:49 ` Lorenzo Pieralisi
2019-03-08 13:07 ` Ulf Hansson
2019-03-08 13:17 ` Lorenzo Pieralisi
2019-03-08 13:23 ` Ulf Hansson
2019-03-08 13:31 ` Lorenzo Pieralisi
2019-03-08 13:43 ` Ulf Hansson
2019-02-28 13:59 ` [PATCH 6/7] drivers: firmware: psci: Simplify error path of psci_dt_init() Ulf Hansson
2019-02-28 13:59 ` [PATCH 7/7] drivers: firmware: psci: Announce support for OS initiated suspend mode Ulf Hansson
2019-03-01 17:28 ` Stephen Boyd
2019-03-04 10:25 ` Ulf Hansson
2019-03-01 17:32 ` Mark Rutland
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