linux-kernel - [PATCH v2 12/13] arm: Set SD_ASYM_CPUCAPACITY for big.LITTLE platforms

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Message-Id: <1466615004-3503-13-git-send-email-morten.rasmussen@arm.com>
Date:	Wed, 22 Jun 2016 18:03:23 +0100
From:	Morten Rasmussen <morten.rasmussen@....com>
To:	peterz@...radead.org, mingo@...hat.com
Cc:	dietmar.eggemann@....com, yuyang.du@...el.com,
	vincent.guittot@...aro.org, mgalbraith@...e.de,
	linux-kernel@...r.kernel.org,
	Morten Rasmussen <morten.rasmussen@....com>,
	Russell King <linux@....linux.org.uk>
Subject: [PATCH v2 12/13] arm: Set SD_ASYM_CPUCAPACITY for big.LITTLE platforms

Set the SD_ASYM_CPUCAPACITY flag for DIE and MC level sched_domains
on big.LITTLE systems.

cc: Russell King <linux@....linux.org.uk>

Signed-off-by: Morten Rasmussen <morten.rasmussen@....com>
---
 arch/arm/kernel/topology.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index ec279d161b32..ab6d9c1835a4 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -78,6 +78,7 @@ static unsigned long *__cpu_capacity;
 #define cpu_capacity(cpu)	__cpu_capacity[cpu]
 
 static unsigned long middle_capacity = 1;
+static unsigned int big_little;
 
 /*
  * Iterate all CPUs' descriptor in DT and compute the efficiency
@@ -151,6 +152,8 @@ static void __init parse_dt_topology(void)
 		middle_capacity = ((max_capacity / 3)
 				>> (SCHED_CAPACITY_SHIFT-1)) + 1;
 
+	if (max_capacity && max_capacity != min_capacity)
+		big_little = 1;
 }
 
 /*
@@ -277,15 +280,29 @@ void store_cpu_topology(unsigned int cpuid)
 
 static inline int cpu_corepower_flags(void)
 {
-	return SD_SHARE_PKG_RESOURCES  | SD_SHARE_POWERDOMAIN;
+	int flags = SD_SHARE_PKG_RESOURCES | SD_SHARE_POWERDOMAIN;
+
+	return big_little ? SD_ASYM_CPUCAPACITY | flags : flags;
+}
+
+static inline int arm_cpu_core_flags(void)
+{
+	int flags = SD_SHARE_PKG_RESOURCES;
+
+	return big_little ? SD_ASYM_CPUCAPACITY | flags : flags;
+}
+
+static inline int arm_cpu_cpu_flags(void)
+{
+	return big_little ? SD_ASYM_CPUCAPACITY : 0;
 }
 
 static struct sched_domain_topology_level arm_topology[] = {
 #ifdef CONFIG_SCHED_MC
 	{ cpu_corepower_mask, cpu_corepower_flags, SD_INIT_NAME(GMC) },
-	{ cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
+	{ cpu_coregroup_mask, arm_cpu_core_flags, SD_INIT_NAME(MC) },
 #endif
-	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
+	{ cpu_cpu_mask, arm_cpu_cpu_flags, SD_INIT_NAME(DIE) },
 	{ NULL, },
 };
 
-- 
1.9.1