firmware: arm_ffa: Implement the notification bind and unbind interface

A receiver endpoint must bind a notification to any sender endpoint
before the latter can signal the notification to the former. The receiver
assigns one or more doorbells to a specific sender. Only the sender can
ring these doorbells.

A receiver uses the FFA_NOTIFICATION_BIND interface to bind one or more
notifications to the sender. A receiver un-binds a notification from a
sender endpoint to stop the notification from being signaled. It uses
the FFA_NOTIFICATION_UNBIND interface to do this.

Allow the FF-A driver to be able to bind and unbind a given notification
ID to a specific partition ID. This will be used to register and
unregister notification callbacks from the FF-A client drivers.

Link: https://lore.kernel.org/r/20231005-ffa_v1-1_notif-v4-3-cddd3237809c@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index c2ab6f4cf29627003e88d0e2e3423b9d895ea967..20f8f4ca8e89b0d7ce1c37fb392c33e5fc53c19b 100644 (file)
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -587,6 +587,35 @@ static int ffa_notification_bitmap_destroy(void)
        return 0;
 }
 
+#define NOTIFICATION_LOW_MASK          GENMASK(31, 0)
+#define NOTIFICATION_HIGH_MASK         GENMASK(63, 32)
+#define NOTIFICATION_BITMAP_HIGH(x)    \
+               ((u32)(FIELD_GET(NOTIFICATION_HIGH_MASK, (x))))
+#define NOTIFICATION_BITMAP_LOW(x)     \
+               ((u32)(FIELD_GET(NOTIFICATION_LOW_MASK, (x))))
+
+static int ffa_notification_bind_common(u16 dst_id, u64 bitmap,
+                                       u32 flags, bool is_bind)
+{
+       ffa_value_t ret;
+       u32 func, src_dst_ids = PACK_TARGET_INFO(dst_id, drv_info->vm_id);
+
+       func = is_bind ? FFA_NOTIFICATION_BIND : FFA_NOTIFICATION_UNBIND;
+
+       invoke_ffa_fn((ffa_value_t){
+                 .a0 = func, .a1 = src_dst_ids, .a2 = flags,
+                 .a3 = NOTIFICATION_BITMAP_LOW(bitmap),
+                 .a4 = NOTIFICATION_BITMAP_HIGH(bitmap),
+                 }, &ret);
+
+       if (ret.a0 == FFA_ERROR)
+               return ffa_to_linux_errno((int)ret.a2);
+       else if (ret.a0 != FFA_SUCCESS)
+               return -EINVAL;
+
+       return 0;
+}
+
 static void ffa_set_up_mem_ops_native_flag(void)
 {
        if (!ffa_features(FFA_FN_NATIVE(MEM_LEND), 0, NULL, NULL) ||