Commit 5f98ecdb authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Konrad Rzeszutek Wilk
Browse files

swiotlb: Export swioltb_nr_tbl and utilize it as appropiate.

By default the io_tlb_nslabs is set to zero, and gets set to
whatever value is passed in via swiotlb_init_with_tbl function.
The default value passed in is 64MB. However, if the user provides
the 'swiotlb=<nslabs>' the default value is ignored and
the value provided by the user is used... Except when the SWIOTLB
is used under Xen - there the default value of 64MB is used and
the Xen-SWIOTLB has no mechanism to get the 'io_tlb_nslabs' filled
out by setup_io_tlb_npages functions. This patch provides a function
for the Xen-SWIOTLB to call to see if the io_tlb_nslabs is set
and if so use that value.
Signed-off-by: default avatarFUJITA Tomonori <>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <>
parent 61c4f2c8
......@@ -147,9 +147,15 @@ void __init xen_swiotlb_init(int verbose)
unsigned long bytes;
int rc;
xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT);
xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
unsigned long nr_tbl;
nr_tbl = swioltb_nr_tbl();
if (nr_tbl)
xen_io_tlb_nslabs = nr_tbl;
else {
xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT);
xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;
......@@ -24,6 +24,7 @@ extern int swiotlb_force;
extern void swiotlb_init(int verbose);
extern void swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose);
extern unsigned long swioltb_nr_tbl(void);
* Enumeration for sync targets
......@@ -110,6 +110,11 @@ setup_io_tlb_npages(char *str)
__setup("swiotlb=", setup_io_tlb_npages);
/* make io_tlb_overflow tunable too? */
unsigned long swioltb_nr_tbl(void)
return io_tlb_nslabs;
/* Note that this doesn't work with highmem page */
static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
volatile void *address)
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