nvme: Don't active memory space until all BARs are configured

In the current current behavior the 2nd and 3rd BARs can be activated
when they're configured with address zero. This change defers the
activation of all BARs until after they've all been configured with an
address.

This enables FreeBSD on Google Compute Engine C4-LSSD Machines.

Sponsored by:		Google
Tested by:		NetApp (previous version)
Reviewed by:		gallatin, imp
Discussed with:		jrtc27 (improved error reporting)
Differential Revision:	https://reviews.freebsd.org/D55541

1 files changed, 37 insertions, 7 deletions

diff --git a/sys/dev/nvme/nvme_pci.c b/sys/dev/nvme/nvme_pci.c
index 5784c6d1be96..74191df52058 100644
--- a/sys/dev/nvme/nvme_pci.c
+++ b/sys/dev/nvme/nvme_pci.c
@@ -151,24 +151,28 @@ nvme_pci_probe (device_t device)
 static int
 nvme_ctrlr_allocate_bar(struct nvme_controller *ctrlr)
 {
+	int error;
+
 	ctrlr->resource_id = PCIR_BAR(0);
 	ctrlr->msix_table_resource_id = -1;
 	ctrlr->msix_table_resource = NULL;
 	ctrlr->msix_pba_resource_id = -1;
 	ctrlr->msix_pba_resource = NULL;
 
+	/*
+	 * Using RF_ACTIVE will set the Memory Space bit in the PCI command register.
+	 * The remaining BARs will get mapped in before they've been programmed with
+	 * an address.  To avoid this we'll not set this flag and instead call
+	 * bus_activate_resource() after all the BARs have been programmed.
+	 */
 	ctrlr->resource = bus_alloc_resource_any(ctrlr->dev, SYS_RES_MEMORY,
-	    &ctrlr->resource_id, RF_ACTIVE);
+	    &ctrlr->resource_id, 0);
 
 	if (ctrlr->resource == NULL) {
 		nvme_printf(ctrlr, "unable to allocate pci resource\n");
 		return (ENOMEM);
 	}
 
-	ctrlr->bus_tag = rman_get_bustag(ctrlr->resource);
-	ctrlr->bus_handle = rman_get_bushandle(ctrlr->resource);
-	ctrlr->regs = (struct nvme_registers *)ctrlr->bus_handle;
-
 	/*
 	 * The NVMe spec allows for the MSI-X tables to be placed behind
 	 *  BAR 4 and/or 5, separate from the control/doorbell registers.
@@ -180,7 +184,7 @@ nvme_ctrlr_allocate_bar(struct nvme_controller *ctrlr)
 	if (ctrlr->msix_table_resource_id >= 0 &&
 	    ctrlr->msix_table_resource_id != ctrlr->resource_id) {
 		ctrlr->msix_table_resource = bus_alloc_resource_any(ctrlr->dev,
-		    SYS_RES_MEMORY, &ctrlr->msix_table_resource_id, RF_ACTIVE);
+		    SYS_RES_MEMORY, &ctrlr->msix_table_resource_id, 0);
 		if (ctrlr->msix_table_resource == NULL) {
 			nvme_printf(ctrlr, "unable to allocate msi-x table resource\n");
 			return (ENOMEM);
@@ -190,13 +194,39 @@ nvme_ctrlr_allocate_bar(struct nvme_controller *ctrlr)
 	    ctrlr->msix_pba_resource_id != ctrlr->resource_id &&
 	    ctrlr->msix_pba_resource_id != ctrlr->msix_table_resource_id) {
 		ctrlr->msix_pba_resource = bus_alloc_resource_any(ctrlr->dev,
-		    SYS_RES_MEMORY, &ctrlr->msix_pba_resource_id, RF_ACTIVE);
+		    SYS_RES_MEMORY, &ctrlr->msix_pba_resource_id, 0);
 		if (ctrlr->msix_pba_resource == NULL) {
 			nvme_printf(ctrlr, "unable to allocate msi-x pba resource\n");
 			return (ENOMEM);
 		}
 	}
 
+	error = bus_activate_resource(ctrlr->dev, ctrlr->resource);
+	if (error) {
+		nvme_printf(ctrlr, "unable to activate pci resource: %d\n", error);
+		return (error);
+	}
+	if (ctrlr->msix_table_resource != NULL) {
+		error = bus_activate_resource(ctrlr->dev, ctrlr->msix_table_resource);
+		if (error) {
+			nvme_printf(ctrlr, "unable to activate msi-x table resource: %d\n",
+			    error);
+			return (error);
+		}
+	}
+	if (ctrlr->msix_pba_resource != NULL) {
+		error = bus_activate_resource(ctrlr->dev, ctrlr->msix_pba_resource);
+		if (error) {
+			nvme_printf(ctrlr, "unable to activate msi-x pba resource: %d\n",
+			    error);
+			return (error);
+		}
+	}
+
+	ctrlr->bus_tag = rman_get_bustag(ctrlr->resource);
+	ctrlr->bus_handle = rman_get_bushandle(ctrlr->resource);
+	ctrlr->regs = (struct nvme_registers *)ctrlr->bus_handle;
+
 	return (0);
 }