Commit 97729b65 authored by Stefano Stabellini's avatar Stefano Stabellini Committed by Juergen Gross
Browse files

xen/swiotlb: check if the swiotlb has already been initialized 



xen_swiotlb_init calls swiotlb_late_init_with_tbl, which fails with
-ENOMEM if the swiotlb has already been initialized.

Add an explicit check io_tlb_default_mem != NULL at the beginning of
xen_swiotlb_init. If the swiotlb is already initialized print a warning
and return -EEXIST.

On x86, the error propagates.

On ARM, we don't actually need a special swiotlb buffer (yet), any
buffer would do. So ignore the error and continue.

CC: boris.ostrovsky@oracle.com
CC: jgross@suse.com
Signed-off-by: default avatarStefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrvsky@oracle.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210512201823.1963-3-sstabellini@kernel.org


Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent 687842ec

arch/arm/xen/mm.c

+7 −1
Original line number Diff line number Diff line
@@ -138,9 +138,15 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) 
static int __init xen_mm_init(void)

{

	struct gnttab_cache_flush cflush;

	int rc;



	if (!xen_swiotlb_detect())

		return 0;

	xen_swiotlb_init();



	rc = xen_swiotlb_init();

	/* we can work with the default swiotlb */

	if (rc < 0 && rc != -EEXIST)

		return rc;



	cflush.op = 0;

	cflush.a.dev_bus_addr = 0;

drivers/xen/swiotlb-xen.c

+5 −0
Original line number Diff line number Diff line
@@ -164,6 +164,11 @@ int __ref xen_swiotlb_init(void) 
	int rc = -ENOMEM;

	char *start;



	if (io_tlb_default_mem != NULL) {

		pr_warn("swiotlb buffer already initialized\n");

		return -EEXIST;

	}



retry:

	m_ret = XEN_SWIOTLB_ENOMEM;

	order = get_order(bytes);