From: Shreyas B Prabhu <shreyas@linux.vnet.ibm.com>
To: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: mpe@ellerman.id.au, benh@au1.ibm.com, paulus@ozlabs.org,
mikey@neuling.org, ego@linux.vnet.ibm.com,
maddy@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
Rob Herring <robh+dt@kernel.org>,
Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
linux-pm@vger.kernel.org
Subject: Re: [PATCH v6 10/11] cpuidle/powernv: Add support for POWER ISA v3 idle states
Date: Tue, 14 Jun 2016 16:17:12 +0530 [thread overview]
Message-ID: <575FE0B0.4030309@linux.vnet.ibm.com> (raw)
In-Reply-To: <20160613153446.GF10634@linaro.org>
On 06/13/2016 09:04 PM, Daniel Lezcano wrote:
> On Wed, Jun 08, 2016 at 11:54:30AM -0500, Shreyas B. Prabhu wrote:
>> POWER ISA v3 defines a new idle processor core mechanism. In summary,
>> a) new instruction named stop is added.
>> b) new per thread SPR named PSSCR is added which controls the behavior
>> of stop instruction.
>>
>> Supported idle states and value to be written to PSSCR register to enter
>> any idle state is exposed via ibm,cpu-idle-state-names and
>> ibm,cpu-idle-state-psscr respectively. To enter an idle state,
>> platform provided power_stop() needs to be invoked with the appropriate
>> PSSCR value.
>>
>> This patch adds support for this new mechanism in cpuidle powernv driver.
>>
>> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>> Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
>> Cc: Rob Herring <robh+dt@kernel.org>
>> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
>> Cc: linux-pm@vger.kernel.org
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: Paul Mackerras <paulus@ozlabs.org>
>> Cc: linuxppc-dev@lists.ozlabs.org
>> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
>> Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
>> ---
>
> [ ... ]
>
>> + rc = of_property_read_string_array(power_mgt,
>> + "ibm,cpu-idle-state-names", names,
>> + dt_idle_states);
>> + if (rc < 0) {
>> + pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-names in DT\n");
>> + goto out_free_latency;
>> + }
>> +
>> + /*
>> + * If the idle states use stop instruction, probe for psscr values
>> + * which are necessary to specify required stop level.
>> + */
>> + if (flags[0] & (OPAL_PM_STOP_INST_FAST | OPAL_PM_STOP_INST_DEEP)) {
>> + psscr_val = kcalloc(dt_idle_states, sizeof(*psscr_val),
>> + GFP_KERNEL);
>
> if (!psscr_val) check missing.
I ignored adding this check because this is part of initcall and we are
unlikely to run out of memory at this state. But I'll add the check in
next version.
>
>> + rc = of_property_read_u64_array(power_mgt,
>> + "ibm,cpu-idle-state-psscr",
>> + psscr_val, dt_idle_states);
>> + if (rc) {
>> + pr_warn("cpuidle-powernv: missing ibm,cpu-idle-states-psscr in DT\n");
>> + goto out_free_psscr;
>> + }
>> + }
>> residency_ns = kzalloc(sizeof(*residency_ns) * dt_idle_states, GFP_KERNEL);
>
> if (!residency_ns) check missing.
>
> I suppose the code is relying on 'of_property_read_u32_array' to check it,
> right ?
I'll add the NULL check for existing kzalloc's in the file as well in
the next version.
Thanks,
Shreyas
next prev parent reply other threads:[~2016-06-14 10:47 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-08 16:54 [PATCH v6 00/11] powerpc/powernv/cpuidle: Add support for POWER ISA v3 idle states Shreyas B. Prabhu
2016-06-08 16:54 ` [PATCH v6 01/11] powerpc/powernv: Use PNV_THREAD_WINKLE macro while requesting for winkle Shreyas B. Prabhu
2016-06-08 16:54 ` [PATCH v6 02/11] powerpc/kvm: make hypervisor state restore a function Shreyas B. Prabhu
2016-06-08 16:54 ` [PATCH v6 03/11] powerpc/powernv: Rename idle_power7.S to idle_power_common.S Shreyas B. Prabhu
2016-06-15 5:31 ` [v6, " Michael Ellerman
2016-06-08 16:54 ` [PATCH v6 04/11] powerpc/powernv: Rename reusable idle functions to hardware agnostic names Shreyas B. Prabhu
2016-06-08 16:54 ` [PATCH v6 05/11] powerpc/powernv: Make pnv_powersave_common more generic Shreyas B. Prabhu
2016-06-08 16:54 ` [PATCH v6 06/11] powerpc/powernv: abstraction for saving SPRs before entering deep idle states Shreyas B. Prabhu
2016-06-08 16:54 ` [PATCH v6 07/11] powerpc/powernv: set power_save func after the idle states are initialized Shreyas B. Prabhu
2016-06-15 5:41 ` [v6, " Michael Ellerman
2016-06-15 6:11 ` Shreyas B Prabhu
2016-06-22 1:54 ` [PATCH v6 " Benjamin Herrenschmidt
2016-06-22 5:11 ` Michael Neuling
2016-06-28 12:10 ` [v6, " Michael Ellerman
2016-06-08 16:54 ` [PATCH v6 08/11] powerpc/powernv: Add platform support for stop instruction Shreyas B. Prabhu
2016-06-15 11:14 ` [v6, " Michael Ellerman
2016-06-15 13:00 ` Shreyas B Prabhu
2016-06-21 6:14 ` Michael Neuling
2016-06-08 16:54 ` [PATCH v6 09/11] cpuidle/powernv: Use CPUIDLE_STATE_MAX instead of MAX_POWERNV_IDLE_STATES Shreyas B. Prabhu
2016-06-13 15:01 ` Daniel Lezcano
2016-06-13 20:58 ` Rafael J. Wysocki
2016-06-08 16:54 ` [PATCH v6 10/11] cpuidle/powernv: Add support for POWER ISA v3 idle states Shreyas B. Prabhu
2016-06-13 15:34 ` Daniel Lezcano
2016-06-14 10:47 ` Shreyas B Prabhu [this message]
2016-06-14 11:29 ` Benjamin Herrenschmidt
2016-06-15 4:57 ` Shreyas B Prabhu
2016-06-13 21:48 ` Benjamin Herrenschmidt
2016-06-14 11:11 ` Shreyas B Prabhu
2016-06-14 11:31 ` Benjamin Herrenschmidt
2016-06-08 16:54 ` [PATCH v6 11/11] powerpc/powernv: Use deepest stop state when cpu is offlined Shreyas B. Prabhu
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