Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1438933

[PATCH v7 09/11] cpuidle/powernv: cleanup powernv_add_idle_states

From "Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com>
Newsgroups linux.kernel
Subject [PATCH v7 09/11] cpuidle/powernv: cleanup powernv_add_idle_states
Date 2016-07-07 22:50 +0200
Message-ID <rSopc-3tL-31@gated-at.bofh.it> (permalink)
References <rSopb-3tL-1@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw

 - Use stack instead of kzalloc'ed memory for variables while probing
   device tree for idle states.
 - Set cap for number of idle states that can be added to
   cpuidle_state_table
 - Minor change in way we check of_property_read_u32_array for error
   for sake of consistency
 - Drop unnecessary "&" while assigning function pointer

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
---
 - New in v7. This was mainly to make the existing code
   consistent with the review comments for new code

 drivers/cpuidle/cpuidle-powernv.c | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 3a763a8..a89f546 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -166,7 +166,9 @@ static int powernv_add_idle_states(void)
 	struct device_node *power_mgt;
 	int nr_idle_states = 1; /* Snooze */
 	int dt_idle_states;
-	u32 *latency_ns, *residency_ns, *flags;
+	u32 latency_ns[CPUIDLE_STATE_MAX];
+	u32 residency_ns[CPUIDLE_STATE_MAX];
+	u32 flags[CPUIDLE_STATE_MAX];
 	int i, rc;
 
 	/* Currently we have snooze statically defined */
@@ -184,22 +186,28 @@ static int powernv_add_idle_states(void)
 		goto out;
 	}
 
-	flags = kzalloc(sizeof(*flags) * dt_idle_states, GFP_KERNEL);
+	/*
+	 * Since snooze is used as first idle state, max idle states allowed is
+	 * CPUIDLE_STATE_MAX -1
+	 */
+	if (dt_idle_states > CPUIDLE_STATE_MAX - 1) {
+		pr_warn("cpuidle-powernv: discovered idle states more than allowed");
+		dt_idle_states = CPUIDLE_STATE_MAX - 1;
+	}
+
 	if (of_property_read_u32_array(power_mgt,
 			"ibm,cpu-idle-state-flags", flags, dt_idle_states)) {
 		pr_warn("cpuidle-powernv : missing ibm,cpu-idle-state-flags in DT\n");
-		goto out_free_flags;
+		goto out;
 	}
 
-	latency_ns = kzalloc(sizeof(*latency_ns) * dt_idle_states, GFP_KERNEL);
-	rc = of_property_read_u32_array(power_mgt,
-		"ibm,cpu-idle-state-latencies-ns", latency_ns, dt_idle_states);
-	if (rc) {
+	if (of_property_read_u32_array(power_mgt,
+		"ibm,cpu-idle-state-latencies-ns", latency_ns,
+		dt_idle_states)) {
 		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
-		goto out_free_latency;
+		goto out;
 	}
 
-	residency_ns = kzalloc(sizeof(*residency_ns) * dt_idle_states, GFP_KERNEL);
 	rc = of_property_read_u32_array(power_mgt,
 		"ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states);
 
@@ -215,7 +223,7 @@ static int powernv_add_idle_states(void)
 			strcpy(powernv_states[nr_idle_states].desc, "Nap");
 			powernv_states[nr_idle_states].flags = 0;
 			powernv_states[nr_idle_states].target_residency = 100;
-			powernv_states[nr_idle_states].enter = &nap_loop;
+			powernv_states[nr_idle_states].enter = nap_loop;
 		}
 
 		/*
@@ -230,7 +238,7 @@ static int powernv_add_idle_states(void)
 			strcpy(powernv_states[nr_idle_states].desc, "FastSleep");
 			powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
 			powernv_states[nr_idle_states].target_residency = 300000;
-			powernv_states[nr_idle_states].enter = &fastsleep_loop;
+			powernv_states[nr_idle_states].enter = fastsleep_loop;
 		}
 #endif
 		powernv_states[nr_idle_states].exit_latency =
@@ -243,12 +251,6 @@ static int powernv_add_idle_states(void)
 
 		nr_idle_states++;
 	}
-
-	kfree(residency_ns);
-out_free_latency:
-	kfree(latency_ns);
-out_free_flags:
-	kfree(flags);
 out:
 	return nr_idle_states;
 }
-- 
2.4.11

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH v7 00/11] powerpc/powernv/cpuidle: Add support for POWER ISA v3 idle states "Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com> - 2016-07-07 22:50 +0200
  [PATCH v7 01/11] powerpc/powernv: Use PNV_THREAD_WINKLE macro while requesting for winkle "Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com> - 2016-07-07 22:50 +0200
  [PATCH v7 08/11] cpuidle/powernv: Use CPUIDLE_STATE_MAX instead of MAX_POWERNV_IDLE_STATES "Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com> - 2016-07-07 22:50 +0200
  [PATCH v7 07/11] powerpc/powernv: Add platform support for stop instruction "Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com> - 2016-07-07 22:50 +0200
    Re: [PATCH v7 07/11] powerpc/powernv: Add platform support for stop  instruction Michael Neuling <mikey@neuling.org> - 2016-07-08 04:30 +0200
      Re: [PATCH v7 07/11] powerpc/powernv: Add platform support for stop  instruction Shreyas B Prabhu <shreyas@linux.vnet.ibm.com> - 2016-07-08 06:30 +0200
        Re: [PATCH v7 07/11] powerpc/powernv: Add platform support for stop  instruction Michael Neuling <mikey@neuling.org> - 2016-07-08 06:30 +0200
  [PATCH v7 10/11] cpuidle/powernv: Add support for POWER ISA v3 idle states "Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com> - 2016-07-07 22:50 +0200
  [PATCH v7 02/11] powerpc/kvm: make hypervisor state restore a function "Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com> - 2016-07-07 22:50 +0200
  [PATCH v7 09/11] cpuidle/powernv: cleanup powernv_add_idle_states "Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com> - 2016-07-07 22:50 +0200
    Re: [PATCH v7 09/11] cpuidle/powernv: cleanup  powernv_add_idle_states Michael Neuling <mikey@neuling.org> - 2016-07-08 04:50 +0200
  [PATCH v7 03/11] powerpc/powernv: Rename idle_power7.S to idle_book3s.S "Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com> - 2016-07-07 22:50 +0200
  [PATCH v7 04/11] powerpc/powernv: Rename reusable idle functions to hardware agnostic names "Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com> - 2016-07-07 22:50 +0200
  [PATCH v7 06/11] powerpc/powernv: abstraction for saving SPRs before entering deep idle states "Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com> - 2016-07-07 22:50 +0200
  [PATCH v7 05/11] powerpc/powernv: Make pnv_powersave_common more generic "Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com> - 2016-07-07 23:00 +0200
  Re: [PATCH v7 00/11] powerpc/powernv/cpuidle: Add support for POWER  ISA v3 idle states Michael Neuling <mikey@neuling.org> - 2016-07-08 04:50 +0200

csiph-web