Merge branch 'linus/master' into rdma.git for-next

rdma.git merge resolution for the 4.19 merge window

Conflicts:
 drivers/infiniband/core/rdma_core.c
   - Use the rdma code and revise with the new spelling for
     atomic_fetch_add_unless
 drivers/nvme/host/rdma.c
   - Replace max_sge with max_send_sge in new blk code
 drivers/nvme/target/rdma.c
   - Use the blk code and revise to use NULL for ib_post_recv when
     appropriate
   - Replace max_sge with max_recv_sge in new blk code
 net/rds/ib_send.c
   - Use the net code and revise to use NULL for ib_post_recv when
     appropriate

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 19 insertions, 17 deletions

diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
index 5bd6c1573295..6b7c1ed58e7e 100644
--- a/drivers/pci/hotplug/acpi_pcihp.c
+++ b/drivers/pci/hotplug/acpi_pcihp.c
@@ -74,20 +74,6 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev)
 	struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
 
 	/*
-	 * Per PCI firmware specification, we should run the ACPI _OSC
-	 * method to get control of hotplug hardware before using it. If
-	 * an _OSC is missing, we look for an OSHP to do the same thing.
-	 * To handle different BIOS behavior, we look for _OSC on a root
-	 * bridge preferentially (according to PCI fw spec). Later for
-	 * OSHP within the scope of the hotplug controller and its parents,
-	 * up to the host bridge under which this controller exists.
-	 */
-	if (shpchp_is_native(pdev))
-		return 0;
-
-	/* If _OSC exists, we should not evaluate OSHP */
-
-	/*
 	 * If there's no ACPI host bridge (i.e., ACPI support is compiled
 	 * into the kernel but the hardware platform doesn't support ACPI),
 	 * there's nothing to do here.
@@ -97,9 +83,25 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev)
 	if (!root)
 		return 0;
 
-	if (root->osc_support_set)
-		goto no_control;
+	/*
+	 * If _OSC exists, it determines whether we're allowed to manage
+	 * the SHPC.  We executed it while enumerating the host bridge.
+	 */
+	if (root->osc_support_set) {
+		if (host->native_shpc_hotplug)
+			return 0;
+		return -ENODEV;
+	}
 
+	/*
+	 * In the absence of _OSC, we're always allowed to manage the SHPC.
+	 * However, if an OSHP method is present, we must execute it so the
+	 * firmware can transfer control to the OS, e.g., direct interrupts
+	 * to the OS instead of to the firmware.
+	 *
+	 * N.B. The PCI Firmware Spec (r3.2, sec 4.8) does not endorse
+	 * searching up the ACPI hierarchy, so the loops below are suspect.
+	 */
 	handle = ACPI_HANDLE(&pdev->dev);
 	if (!handle) {
 		/*
@@ -128,7 +130,7 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev)
 		if (ACPI_FAILURE(status))
 			break;
 	}
-no_control:
+
 	pci_info(pdev, "Cannot get control of SHPC hotplug\n");
 	kfree(string.pointer);
 	return -ENODEV;