This patch introduces swiotlb_get_type() in order to calculate which swiotlb buffer the given DMA address is belong to.
This is to prepare to enable 64-bit swiotlb.
Cc: Joe Jin joe.jin@oracle.com Signed-off-by: Dongli Zhang dongli.zhang@oracle.com --- include/linux/swiotlb.h | 14 ++++++++++++++ kernel/dma/swiotlb.c | 2 ++ 2 files changed, 16 insertions(+)
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 777046cd4d1b..3d5980d77810 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -3,6 +3,7 @@ #define __LINUX_SWIOTLB_H
#include <linux/dma-direction.h> +#include <linux/errno.h> #include <linux/init.h> #include <linux/types.h> #include <linux/limits.h> @@ -23,6 +24,8 @@ enum swiotlb_t { SWIOTLB_MAX, };
+extern int swiotlb_nr; + /* * Maximum allowable number of contiguous slabs to map, * must be a power of 2. What is the appropriate value ? @@ -84,6 +87,17 @@ static inline bool is_swiotlb_buffer(phys_addr_t paddr) paddr < io_tlb_end[SWIOTLB_LO]; }
+static inline int swiotlb_get_type(phys_addr_t paddr) +{ + int i; + + for (i = 0; i < swiotlb_nr; i++) + if (paddr >= io_tlb_start[i] && paddr < io_tlb_end[i]) + return i; + + return -ENOENT; +} + void __init swiotlb_exit(void); unsigned int swiotlb_max_segment(void); size_t swiotlb_max_mapping_size(struct device *dev); diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 1fbb65daa2dd..c91d3d2c3936 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -109,6 +109,8 @@ static DEFINE_SPINLOCK(io_tlb_lock);
static int late_alloc;
+int swiotlb_nr = 1; + static int __init setup_io_tlb_npages(char *str) {