mmc: host: sdhci: allow definition of pm QoS via dts file

Add a new dts entry to define the CPU affinity in order to maintain
the IRQ pm_qos (Quality of Service) for targets that don't have little
cluster and allow setting the pm_qos to the little cluster,
to improve its performance.

Change-Id: Icf6125066d96331392d98a387974e54c96553306
Signed-off-by: Vince Leung <vincentl@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>

Documentation/devicetree/bindings/mmc/sdhci-msm.txt

@@ -60,6 +60,19 @@ In the following, <supply> can be vdd (flash core voltage) or vdd-io (I/O voltag
 		- pinctrl-names
 		- pinctrl-0, pinctrl-1,.. pinctrl-n
 
+        - qcom,cpu-affinity: this is a string that specifies the pm QoS request
+	  type. The supported cpu affinity modes are :
+	  "all_cores" - PM_QOS_REQ_ALL_CORES is applicable to all CPU cores that
+	  are online and this would have a power impact when there are more
+	  number of CPUs.
+	  "affine_irq" - PM_QOS_REQ_AFFINE_IRQ request type shall update/apply
+	  the vote only to that CPU to which this IRQ's affinity is set to.
+	  "affine_cores" - PM_QOS_REQ_AFFINE_CORES request type is used for
+	  targets that have little cluster and will update/apply the vote to
+	  all the cores in the little cluster.
+	  The default CPU affinity mode is PM_QOS_REQ_AFFINE_IRQ to maintain
+	  backward compatibility.
+
 Example:
 
 	aliases {

drivers/mmc/host/sdhci-msm.c

@@ -266,6 +266,7 @@ struct sdhci_msm_pltfm_data {
 	struct sdhci_msm_bus_voting_data *voting_data;
 	u32 *sup_clk_table;
 	unsigned char sup_clk_cnt;
+	enum pm_qos_req_type cpu_affinity_type;
 };
 
 struct sdhci_msm_bus_vote {
@@ -1402,6 +1403,30 @@ out:
 	return ret;
 }
 
+#ifdef CONFIG_SMP
+static void sdhci_msm_populate_affinity_type(struct sdhci_msm_pltfm_data *pdata,
+					     struct device_node *np)
+{
+	const char *cpu_affinity = NULL;
+
+	pdata->cpu_affinity_type = PM_QOS_REQ_AFFINE_IRQ;
+	if (!of_property_read_string(np, "qcom,cpu-affinity",
+				    &cpu_affinity)) {
+		if (!strcmp(cpu_affinity, "all_cores"))
+			pdata->cpu_affinity_type = PM_QOS_REQ_ALL_CORES;
+		else if (!strcmp(cpu_affinity, "affine_cores"))
+			pdata->cpu_affinity_type = PM_QOS_REQ_AFFINE_CORES;
+		else if (!strcmp(cpu_affinity, "affine_irq"))
+			pdata->cpu_affinity_type = PM_QOS_REQ_AFFINE_IRQ;
+	}
+}
+#else
+static void sdhci_msm_populate_affinity_type(struct sdhci_msm_pltfm_data *pdata,
+					     struct device_node *np)
+{
+}
+#endif
+
 /* Parse platform data */
 static struct sdhci_msm_pltfm_data *sdhci_msm_populate_pdata(struct device *dev)
 {
@@ -1508,6 +1533,8 @@ static struct sdhci_msm_pltfm_data *sdhci_msm_populate_pdata(struct device *dev)
 	if (of_get_property(np, "qcom,nonhotplug", NULL))
 		pdata->nonhotplug = true;
 
+	sdhci_msm_populate_affinity_type(pdata, np);
+
 	return pdata;
 out:
 	return NULL;
@@ -3061,6 +3088,7 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 		msm_host->mmc->caps2 |= MMC_CAP2_NONHOTPLUG;
 
 	host->cpu_dma_latency_us = msm_host->pdata->cpu_dma_latency_us;
+	host->pm_qos_req_dma.type = msm_host->pdata->cpu_affinity_type;
 
 	init_completion(&msm_host->pwr_irq_completion);
 

drivers/mmc/host/sdhci.c

@@ -3218,7 +3218,6 @@ EXPORT_SYMBOL_GPL(sdhci_alloc_host);
 #ifdef CONFIG_SMP
 static void sdhci_set_pmqos_req_type(struct sdhci_host *host)
 {
-
 	/*
 	 * The default request type PM_QOS_REQ_ALL_CORES is
 	 * applicable to all CPU cores that are online and
@@ -3226,9 +3225,14 @@ static void sdhci_set_pmqos_req_type(struct sdhci_host *host)
 	 * number of CPUs. This new PM_QOS_REQ_AFFINE_IRQ request
 	 * type shall update/apply the vote only to that CPU to
 	 * which this IRQ's affinity is set to.
+	 * PM_QOS_REQ_AFFINE_CORES request type is used for targets that have
+	 * little cluster and will update/apply the vote to all the cores in
+	 * the little cluster.
 	 */
-	host->pm_qos_req_dma.type = PM_QOS_REQ_AFFINE_IRQ;
-	host->pm_qos_req_dma.irq = host->irq;
+	if (host->pm_qos_req_dma.type == PM_QOS_REQ_AFFINE_CORES)
+		host->pm_qos_req_dma.cpus_affine.bits[0] = 0x0F;
+	else if (host->pm_qos_req_dma.type == PM_QOS_REQ_AFFINE_IRQ)
+		host->pm_qos_req_dma.irq = host->irq;
 }
 #else
 static void sdhci_set_pmqos_req_type(struct sdhci_host *host)