commit 388cc2e2d8cb435d3a6632e225db431ba903f7cf
author Steve Muckle <smuckle@codeaurora.org> Wed Nov 21 15:47:15 2012 -0800
committer Sudhir Sharma <sudsha@codeaurora.org> Mon Dec 10 11:39:40 2012 -0800
tree 130da007ec7c2930585fed2d83d27815a4c7c35e
parent 28ddcddd71e11d6e238d8848340fd81ed0cf411a

msm: dcvs: set algo params according to number of online CPUs

It is desirable for performance reasons to be able to run dcvs
with different algorithm parameters depending on the number of
CPUs that are online. The algorithm parameters are already replicated
per-CPU, but all CPUs operate in DCVS with the same parameters at
any given time.

These per-CPU parameters now correspond to the total number of CPUs
online. For example, if 2 CPUs are online, the algorithm parameters
for CPU2 are used.

Change-Id: If308a2fa949ac669823e759e0fd8e2cdbf6e4c03
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
(cherry picked from commit c48381e2336125410549d7df1425dc8009c0c495)

arch/arm/mach-msm/include/mach/msm_dcvs.h

diff --git a/arch/arm/mach-msm/include/mach/msm_dcvs.h b/arch/arm/mach-msm/include/mach/msm_dcvs.h
index 49841ea..2ad7d22 100644
--- a/arch/arm/mach-msm/include/mach/msm_dcvs.h
+++ b/arch/arm/mach-msm/include/mach/msm_dcvs.h
@@ -164,4 +164,14 @@
  * or the number of CPUs online, requires it.
  */
 extern void msm_dcvs_apply_gpu_floor(unsigned long cpu_freq);
+
+/**
+ * msm_dcvs_update_algo_params
+ * @return:
+ *      0 on success, < 0 on error
+ *
+ * Updates the DCVS algorithm with parameters depending on the
+ * number of CPUs online.
+ */
+extern int msm_dcvs_update_algo_params(void);
 #endif

arch/arm/mach-msm/msm_dcvs.c

diff --git a/arch/arm/mach-msm/msm_dcvs.c b/arch/arm/mach-msm/msm_dcvs.c
index 13cc170..41afd24 100644
--- a/arch/arm/mach-msm/msm_dcvs.c
+++ b/arch/arm/mach-msm/msm_dcvs.c
@@ -547,6 +547,36 @@
 	return HRTIMER_NORESTART;
 }
 
+int msm_dcvs_update_algo_params(void)
+{
+	static struct msm_dcvs_algo_param curr_params;
+	static DEFINE_MUTEX(param_update_mutex);
+	struct msm_dcvs_algo_param *new_params;
+	int cpu, ret = 0;
+
+	mutex_lock(&param_update_mutex);
+	new_params = &core_list[CPU_OFFSET + num_online_cpus() - 1].algo_param;
+
+	if (memcmp(&curr_params, new_params,
+		   sizeof(struct msm_dcvs_algo_param))) {
+		for_each_possible_cpu(cpu) {
+			ret = msm_dcvs_scm_set_algo_params(CPU_OFFSET + cpu,
+							   new_params);
+			if (ret) {
+				pr_err("scm set algo params failed on cpu %d, ret %d\n",
+				       cpu, ret);
+				mutex_unlock(&param_update_mutex);
+				return ret;
+			}
+		}
+		memcpy(&curr_params, new_params,
+		       sizeof(struct msm_dcvs_algo_param));
+	}
+
+	mutex_unlock(&param_update_mutex);
+	return ret;
+}
+
 /* Helper functions and macros for sysfs nodes for a core */
 #define CORE_FROM_ATTRIBS(attr, name) \
 	container_of(container_of(attr, struct core_attribs, name), \
@@ -601,12 +631,9 @@
 	} else { \
 		uint32_t old_val = core->algo_param._name; \
 		core->algo_param._name = val; \
-		ret = msm_dcvs_scm_set_algo_params(core->dcvs_core_id, \
-				&core->algo_param); \
+		ret = msm_dcvs_update_algo_params(); \
 		if (ret) { \
 			core->algo_param._name = old_val; \
-			__err("Error(%d) in setting %d for algo param %s\n",\
-					ret, val, __stringify(_name)); \
 		} \
 	} \
 	return count; \

arch/arm/mach-msm/msm_mpdecision.c

diff --git a/arch/arm/mach-msm/msm_mpdecision.c b/arch/arm/mach-msm/msm_mpdecision.c
index d906b51..94b546a 100644
--- a/arch/arm/mach-msm/msm_mpdecision.c
+++ b/arch/arm/mach-msm/msm_mpdecision.c
@@ -392,6 +392,7 @@
 				}
 		msm_mpd.hpupdate = HPUPDATE_WAITING;
 		msm_dcvs_apply_gpu_floor(0);
+		msm_dcvs_update_algo_params();
 	}
 
 	return 0;