From 1c808fcd859f5ce24132a903a4c7c9996e0513b1 Mon Sep 17 00:00:00 2001
From: Michal Krawczyk <mk@semihalf.com>
Date: Thu, 18 Feb 2021 10:00:58 +0100
Subject: [PATCH] Allocate BAR for ENA MSIx vector table

In the new ENA-based instances like c6gn, the vector table moved to a
new PCIe bar - BAR1. Previously it was always located on the BAR0, so
the resources were already allocated together with the registers.

As the FreeBSD isn't doing any resource allocation behind the scenes,
the driver is responsible to allocate them explicitly, before other
parts of the OS (like the PCI code allocating MSIx) will be able to
access them.

To determine dynamically BAR on which the MSIx vector table is present
the pci_msix_table_bar() is being used and the new BAR is allocated if
needed.

Submitted by: Michal Krawczyk <mk@semihalf.com>
Obtained from: Semihalf
Sponsored by: Amazon, Inc
MFC after: 3 days
---
 sys/dev/ena/ena.c | 21 +++++++++++++++++++++
 sys/dev/ena/ena.h |  4 +++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/sys/dev/ena/ena.c b/sys/dev/ena/ena.c
index b0e05f23b563..680eb0e9d049 100644
--- a/sys/dev/ena/ena.c
+++ b/sys/dev/ena/ena.c
@@ -299,6 +299,11 @@ ena_free_pci_resources(struct ena_adapter *adapter)
 		bus_release_resource(pdev, SYS_RES_MEMORY,
 		    PCIR_BAR(ENA_REG_BAR), adapter->registers);
 	}
+
+	if (adapter->msix != NULL) {
+		bus_release_resource(pdev, SYS_RES_MEMORY,
+		    adapter->msix_rid, adapter->msix);
+	}
 }
 
 static int
@@ -3532,6 +3537,7 @@ ena_attach(device_t pdev)
 	struct ena_adapter *adapter;
 	struct ena_com_dev *ena_dev = NULL;
 	uint32_t max_num_io_queues;
+	int msix_rid;
 	int rid, rc;
 
 	adapter = device_get_softc(pdev);
@@ -3570,6 +3576,20 @@ ena_attach(device_t pdev)
 		goto err_dev_free;
 	}
 
+	/* MSIx vector table may reside on BAR0 with registers or on BAR1. */
+	msix_rid = pci_msix_table_bar(pdev);
+	if (msix_rid != rid) {
+		adapter->msix = bus_alloc_resource_any(pdev, SYS_RES_MEMORY,
+		    &msix_rid, RF_ACTIVE);
+		if (unlikely(adapter->msix == NULL)) {
+			device_printf(pdev,
+			    "unable to allocate bus resource: msix!\n");
+			rc = ENOMEM;
+			goto err_pci_free;
+		}
+		adapter->msix_rid = msix_rid;
+	}
+
 	ena_dev->bus = malloc(sizeof(struct ena_bus), M_DEVBUF,
 	    M_WAITOK | M_ZERO);
 
@@ -3735,6 +3755,7 @@ ena_attach(device_t pdev)
 	ena_com_mmio_reg_read_request_destroy(ena_dev);
 err_bus_free:
 	free(ena_dev->bus, M_DEVBUF);
+err_pci_free:
 	ena_free_pci_resources(adapter);
 err_dev_free:
 	free(ena_dev, M_DEVBUF);
diff --git a/sys/dev/ena/ena.h b/sys/dev/ena/ena.h
index 28da047e2e1b..f3e92f31341a 100644
--- a/sys/dev/ena/ena.h
+++ b/sys/dev/ena/ena.h
@@ -41,7 +41,7 @@
 
 #define DRV_MODULE_VER_MAJOR	2
 #define DRV_MODULE_VER_MINOR	3
-#define DRV_MODULE_VER_SUBMINOR 0
+#define DRV_MODULE_VER_SUBMINOR 1
 
 #define DRV_MODULE_NAME		"ena"
 
@@ -398,6 +398,8 @@ struct ena_adapter {
 	/* OS resources */
 	struct resource *memory;
 	struct resource *registers;
+	struct resource *msix;
+	int msix_rid;
 
 	struct sx global_lock;