From: Stefano Stabellini <stefano.stabellini@xilinx.com>
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: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Boris Ostrovsky <boris.ostrvsky@oracle.com>
---
Changes in v2:
- use pr_warn
- add reviewed-by
---
arch/arm/xen/mm.c | 8 +++++++-
drivers/xen/swiotlb-xen.c | 5 +++++
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index 223b1151fd7d..a7e54a087b80 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -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;
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 4c89afc0df62..24d11861ac7d 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -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);
--
2.17.1