[PATCH 4/4] PCI: pci-epf-test: Add support to defer core initialization

[Vidya Sagar]

Add support to defer core initialization and to receive a notifier
when core is ready to accommodate platforms where core is not for
initialization untile reference clock from host is available.

Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
---
 drivers/pci/endpoint/functions/pci-epf-test.c | 114 ++++++++++++------
 1 file changed, 77 insertions(+), 37 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index bddff15052cc..068024fab544 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -360,18 +360,6 @@ static void pci_epf_test_cmd_handler(struct work_struct *work)
 			   msecs_to_jiffies(1));
 }
 
-static int pci_epf_test_notifier(struct notifier_block *nb, unsigned long val,
-				 void *data)
-{
-	struct pci_epf *epf = container_of(nb, struct pci_epf, nb);
-	struct pci_epf_test *epf_test = epf_get_drvdata(epf);
-
-	queue_delayed_work(kpcitest_workqueue, &epf_test->cmd_handler,
-			   msecs_to_jiffies(1));
-
-	return NOTIFY_OK;
-}
-
 static void pci_epf_test_unbind(struct pci_epf *epf)
 {
 	struct pci_epf_test *epf_test = epf_get_drvdata(epf);
@@ -428,6 +416,78 @@ static int pci_epf_test_set_bar(struct pci_epf *epf)
 	return 0;
 }
 
+static int pci_epf_test_core_init(struct pci_epf *epf)
+{
+	struct pci_epf_header *header = epf->header;
+	const struct pci_epc_features *epc_features;
+	struct pci_epc *epc = epf->epc;
+	struct device *dev = &epf->dev;
+	bool msix_capable = false;
+	bool msi_capable = true;
+	int ret;
+
+	epc_features = pci_epc_get_features(epc, epf->func_no);
+	if (epc_features) {
+		msix_capable = epc_features->msix_capable;
+		msi_capable = epc_features->msi_capable;
+	}
+
+	ret = pci_epc_write_header(epc, epf->func_no, header);
+	if (ret) {
+		dev_err(dev, "Configuration header write failed\n");
+		return ret;
+	}
+
+	ret = pci_epf_test_set_bar(epf);
+	if (ret)
+		return ret;
+
+	if (msi_capable) {
+		ret = pci_epc_set_msi(epc, epf->func_no, epf->msi_interrupts);
+		if (ret) {
+			dev_err(dev, "MSI configuration failed\n");
+			return ret;
+		}
+	}
+
+	if (msix_capable) {
+		ret = pci_epc_set_msix(epc, epf->func_no, epf->msix_interrupts);
+		if (ret) {
+			dev_err(dev, "MSI-X configuration failed\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int pci_epf_test_notifier(struct notifier_block *nb, unsigned long val,
+				 void *data)
+{
+	struct pci_epf *epf = container_of(nb, struct pci_epf, nb);
+	struct pci_epf_test *epf_test = epf_get_drvdata(epf);
+	int ret;
+
+	switch (val) {
+	case CORE_INIT:
+		ret = pci_epf_test_core_init(epf);
+		if (ret)
+			return NOTIFY_BAD;
+		break;
+
+	case LINK_UP:
+		queue_delayed_work(kpcitest_workqueue, &epf_test->cmd_handler,
+				   msecs_to_jiffies(1));
+		break;
+
+	default:
+		dev_err(&epf->dev, "Invalid EPF test notifier event\n");
+		return NOTIFY_BAD;
+	}
+
+	return NOTIFY_OK;
+}
+
 static int pci_epf_test_alloc_space(struct pci_epf *epf)
 {
 	struct pci_epf_test *epf_test = epf_get_drvdata(epf);
@@ -496,12 +556,11 @@ static int pci_epf_test_bind(struct pci_epf *epf)
 {
 	int ret;
 	struct pci_epf_test *epf_test = epf_get_drvdata(epf);
-	struct pci_epf_header *header = epf->header;
 	const struct pci_epc_features *epc_features;
 	enum pci_barno test_reg_bar = BAR_0;
 	struct pci_epc *epc = epf->epc;
-	struct device *dev = &epf->dev;
 	bool linkup_notifier = false;
+	bool skip_core_init = false;
 	bool msix_capable = false;
 	bool msi_capable = true;
 
@@ -511,6 +570,7 @@ static int pci_epf_test_bind(struct pci_epf *epf)
 	epc_features = pci_epc_get_features(epc, epf->func_no);
 	if (epc_features) {
 		linkup_notifier = epc_features->linkup_notifier;
+		skip_core_init = epc_features->skip_core_init;
 		msix_capable = epc_features->msix_capable;
 		msi_capable = epc_features->msi_capable;
 		test_reg_bar = pci_epc_get_first_free_bar(epc_features);
@@ -520,34 +580,14 @@ static int pci_epf_test_bind(struct pci_epf *epf)
 	epf_test->test_reg_bar = test_reg_bar;
 	epf_test->epc_features = epc_features;
 
-	ret = pci_epc_write_header(epc, epf->func_no, header);
-	if (ret) {
-		dev_err(dev, "Configuration header write failed\n");
-		return ret;
-	}
-
 	ret = pci_epf_test_alloc_space(epf);
 	if (ret)
 		return ret;
 
-	ret = pci_epf_test_set_bar(epf);
-	if (ret)
-		return ret;
-
-	if (msi_capable) {
-		ret = pci_epc_set_msi(epc, epf->func_no, epf->msi_interrupts);
-		if (ret) {
-			dev_err(dev, "MSI configuration failed\n");
-			return ret;
-		}
-	}
-
-	if (msix_capable) {
-		ret = pci_epc_set_msix(epc, epf->func_no, epf->msix_interrupts);
-		if (ret) {
-			dev_err(dev, "MSI-X configuration failed\n");
+	if (!skip_core_init) {
+		ret = pci_epf_test_core_init(epf);
+		if (ret)
 			return ret;
-		}
 	}
 
 	if (linkup_notifier) {
-- 
2.17.1