swiotlb: remove unused swiotlb_alloc()

Nobody uses swiotlb_alloc().
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Becky Bruce <beckyb@kernel.crashing.org>

arch/x86/kernel/pci-swiotlb.c

@@ -13,11 +13,6 @@
 
 int swiotlb __read_mostly;
 
-void *swiotlb_alloc(unsigned order, unsigned long nslabs)
-{
-	return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
-}
-
 dma_addr_t swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
 {
 	return paddr;

include/linux/swiotlb.h

@@ -23,8 +23,6 @@ struct scatterlist;
 extern void
 swiotlb_init(void);
 
-extern void *swiotlb_alloc(unsigned order, unsigned long nslabs);
-
 extern dma_addr_t swiotlb_phys_to_bus(struct device *hwdev,
 				      phys_addr_t address);
 extern phys_addr_t swiotlb_bus_to_phys(struct device *hwdev,

lib/swiotlb.c

@@ -114,11 +114,6 @@ setup_io_tlb_npages(char *str)
 __setup("swiotlb=", setup_io_tlb_npages);
 /* make io_tlb_overflow tunable too? */
 
-void * __weak swiotlb_alloc(unsigned order, unsigned long nslabs)
-{
-	return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
-}
-
 dma_addr_t __weak swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
 {
 	return paddr;
@@ -240,7 +235,8 @@ swiotlb_late_init_with_default_size(size_t default_size)
 	bytes = io_tlb_nslabs << IO_TLB_SHIFT;
 
 	while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
-		io_tlb_start = swiotlb_alloc(order, io_tlb_nslabs);
+		io_tlb_start = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
+							order);
 		if (io_tlb_start)
 			break;
 		order--;