In the case of swiotlb we already have the start of the region and the number
of slabs that give us the region size. Instead of having to call
virt_to_phys on two pointers we can just take advantage of the fact that the
region is linear and just compute the end based on the start plus the size.
Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
---
lib/swiotlb.c | 25 ++++++++++++-------------
1 files changed, 12 insertions(+), 13 deletions(-)
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index f114bf6..5cc4d4e 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -57,11 +57,11 @@ int swiotlb_force;
* swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this
* API.
*/
-static char *io_tlb_start, *io_tlb_end;
+static char *io_tlb_start;
/*
- * The number of IO TLB blocks (in groups of 64) between io_tlb_start and
- * io_tlb_end. This is command line adjustable via setup_io_tlb_npages.
+ * The number of IO TLB blocks (in groups of 64).
+ * This is command line adjustable via setup_io_tlb_npages.
*/
static unsigned long io_tlb_nslabs;
@@ -128,11 +128,11 @@ void swiotlb_print_info(void)
phys_addr_t pstart, pend;
pstart = virt_to_phys(io_tlb_start);
- pend = virt_to_phys(io_tlb_end);
+ pend = pstart + bytes;
printk(KERN_INFO "software IO TLB [mem %#010llx-%#010llx] (%luMB) mapped at [%p-%p]\n",
(unsigned long long)pstart, (unsigned long long)pend - 1,
- bytes >> 20, io_tlb_start, io_tlb_end - 1);
+ bytes >> 20, io_tlb_start, io_tlb_start + bytes - 1);
}
void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
@@ -143,12 +143,10 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
io_tlb_nslabs = nslabs;
io_tlb_start = tlb;
- io_tlb_end = io_tlb_start + bytes;
/*
* Allocate and initialize the free list array. This array is used
* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
- * between io_tlb_start and io_tlb_end.
*/
io_tlb_list = alloc_bootmem_pages(PAGE_ALIGN(io_tlb_nslabs * sizeof(int)));
for (i = 0; i < io_tlb_nslabs; i++)
@@ -254,14 +252,12 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
io_tlb_nslabs = nslabs;
io_tlb_start = tlb;
- io_tlb_end = io_tlb_start + bytes;
memset(io_tlb_start, 0, bytes);
/*
* Allocate and initialize the free list array. This array is used
* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
- * between io_tlb_start and io_tlb_end.
*/
io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
get_order(io_tlb_nslabs * sizeof(int)));
@@ -304,7 +300,6 @@ cleanup3:
sizeof(int)));
io_tlb_list = NULL;
cleanup2:
- io_tlb_end = NULL;
io_tlb_start = NULL;
io_tlb_nslabs = 0;
return -ENOMEM;
@@ -339,8 +334,10 @@ void __init swiotlb_free(void)
static int is_swiotlb_buffer(phys_addr_t paddr)
{
- return paddr >= virt_to_phys(io_tlb_start) &&
- paddr < virt_to_phys(io_tlb_end);
+ phys_addr_t swiotlb_start = virt_to_phys(io_tlb_start);
+
+ return paddr >= swiotlb_start &&
+ paddr < (swiotlb_start + (io_tlb_nslabs << IO_TLB_SHIFT));
}
/*
@@ -938,6 +935,8 @@ EXPORT_SYMBOL(swiotlb_dma_mapping_error);
int
swiotlb_dma_supported(struct device *hwdev, u64 mask)
{
- return swiotlb_virt_to_bus(hwdev, io_tlb_end - 1) <= mask;
+ unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT;
+
+ return swiotlb_virt_to_bus(hwdev, io_tlb_start + bytes - 1) <= mask;
}
EXPORT_SYMBOL(swiotlb_dma_supported);
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