Re: [PATCH 2/5] swiotlb: Add is_swiotlb_active() function

On Wed, Jan 23, 2019 at 10:27:55PM +0100, Christoph Hellwig wrote:

On Wed, Jan 23, 2019 at 05:30:46PM +0100, Joerg Roedel wrote:

quoted

+bool is_swiotlb_active(void)
+{
+	return !no_iotlb_memory;
+}

As I've just introduced and fixed a bug in this area in the current
cycle - I don't think no_iotlb_memory is what your want (and maybe
not useful at all): if the arch valls swiotlb_exit after previously
initializing a buffer it won't be set.  You probably want to check
for non-zero io_tlb_start and/or io_tlb_end.

Okay, but that requires that I also set io_tlb_start and friends back to
zero in the failure path of swiotlb_init(). Otherwise it could be left
non-zero in case swiotlb_init_with_tbl() returns an error.


Regards,

	Joerg