firmware: arm_ffa: Skip creation of the notification bitmaps

JIRA: https://issues.redhat.com/browse/RHEL-102691

commit 2b9c66d
Author: Jens Wiklander <jens.wiklander@linaro.org>
Date: Thu, 11 Apr 2024 13:57:32 +0100

    When the FF-A driver is running inside a guest VM under an hypervisor,
    the driver/guest VM doesn't have the permission/capability to request
    the creation of notification bitmaps. For a VM, the hypervisor reserves
    memory for its VM and hypervisor framework notification bitmaps and the
    SPMC reserves memory for its SP and SPMC framework notification bitmaps
    before the hypervisor initializes it.

    The hypervisor does not initialize a VM if memory cannot be reserved
    for all its notification bitmaps. So the creation of all the necessary
    bitmaps are already done when the driver initialises and hence it can be
    skipped. We rely on FFA_FEATURES(FFA_NOTIFICATION_BITMAP_CREATE) to fail
    when running in the guest to handle this in the driver.

    Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
    Link: https://lore.kernel.org/r/20240411-ffa_npi_support-v2-1-927a670254e6@arm.com
    Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Signed-off-by: Marcin Juszkiewicz <mjuszkiewicz@redhat.com>

Author: hrw

drivers/firmware/arm_ffa/driver.c

@@ -1442,17 +1442,15 @@ static void ffa_notifications_setup(void)
 	int ret, irq;
 
 	ret = ffa_features(FFA_NOTIFICATION_BITMAP_CREATE, 0, NULL, NULL);
-	if (ret) {
-		pr_info("Notifications not supported, continuing with it ..\n");
-		return;
-	}
+	if (!ret) {
+		ret = ffa_notification_bitmap_create();
+		if (ret) {
+			pr_err("Notification bitmap create error %d\n", ret);
+			return;
+		}
 
-	ret = ffa_notification_bitmap_create();
-	if (ret) {
-		pr_info("Notification bitmap create error %d\n", ret);
-		return;
+		drv_info->bitmap_created = true;
 	}
-	drv_info->bitmap_created = true;
 
 	irq = ffa_sched_recv_irq_map();
 	if (irq <= 0) {