From ee3f6ba896c7e62004b677b0018a0b29b9b26472 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Mon, 15 Oct 2012 10:19:34 -0700 Subject: swiotlb: Make io_tlb_overflow_buffer a physical address This change makes it so that we can avoid virt_to_phys overhead when using the io_tlb_overflow_buffer. My original plan was to completely remove the value and replace it with a constant but I had seen that there were recent patches that stated this couldn't be done until all device drivers that depended on that functionality be updated. Signed-off-by: Alexander Duyck Signed-off-by: Konrad Rzeszutek Wilk diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 8c4791f..f8c0d4e 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -70,7 +70,7 @@ static unsigned long io_tlb_nslabs; */ static unsigned long io_tlb_overflow = 32*1024; -static void *io_tlb_overflow_buffer; +static phys_addr_t io_tlb_overflow_buffer; /* * This is a free list describing the number of free entries available from @@ -138,6 +138,7 @@ void swiotlb_print_info(void) void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) { + void *v_overflow_buffer; unsigned long i, bytes; bytes = nslabs << IO_TLB_SHIFT; @@ -147,6 +148,15 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) io_tlb_end = io_tlb_start + bytes; /* + * Get the overflow emergency buffer + */ + v_overflow_buffer = alloc_bootmem_low_pages(PAGE_ALIGN(io_tlb_overflow)); + if (!v_overflow_buffer) + panic("Cannot allocate SWIOTLB overflow buffer!\n"); + + io_tlb_overflow_buffer = __pa(v_overflow_buffer); + + /* * 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. @@ -157,12 +167,6 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) io_tlb_index = 0; io_tlb_orig_addr = alloc_bootmem_pages(PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t))); - /* - * Get the overflow emergency buffer - */ - io_tlb_overflow_buffer = alloc_bootmem_low_pages(PAGE_ALIGN(io_tlb_overflow)); - if (!io_tlb_overflow_buffer) - panic("Cannot allocate SWIOTLB overflow buffer!\n"); if (verbose) swiotlb_print_info(); } @@ -252,6 +256,7 @@ int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) { unsigned long i, bytes; + unsigned char *v_overflow_buffer; bytes = nslabs << IO_TLB_SHIFT; @@ -262,6 +267,16 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) memset(tlb, 0, bytes); /* + * Get the overflow emergency buffer + */ + v_overflow_buffer = (void *)__get_free_pages(GFP_DMA, + get_order(io_tlb_overflow)); + if (!v_overflow_buffer) + goto cleanup2; + + io_tlb_overflow_buffer = virt_to_phys(v_overflow_buffer); + + /* * 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. @@ -269,7 +284,7 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL, get_order(io_tlb_nslabs * sizeof(int))); if (!io_tlb_list) - goto cleanup2; + goto cleanup3; for (i = 0; i < io_tlb_nslabs; i++) io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE); @@ -280,18 +295,10 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) get_order(io_tlb_nslabs * sizeof(phys_addr_t))); if (!io_tlb_orig_addr) - goto cleanup3; + goto cleanup4; memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t)); - /* - * Get the overflow emergency buffer - */ - io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA, - get_order(io_tlb_overflow)); - if (!io_tlb_overflow_buffer) - goto cleanup4; - swiotlb_print_info(); late_alloc = 1; @@ -299,13 +306,13 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) return 0; cleanup4: - free_pages((unsigned long)io_tlb_orig_addr, - get_order(io_tlb_nslabs * sizeof(phys_addr_t))); - io_tlb_orig_addr = NULL; -cleanup3: free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs * sizeof(int))); io_tlb_list = NULL; +cleanup3: + free_pages((unsigned long)v_overflow_buffer, + get_order(io_tlb_overflow)); + io_tlb_overflow_buffer = 0; cleanup2: io_tlb_end = 0; io_tlb_start = 0; @@ -315,11 +322,11 @@ cleanup2: void __init swiotlb_free(void) { - if (!io_tlb_overflow_buffer) + if (!io_tlb_orig_addr) return; if (late_alloc) { - free_pages((unsigned long)io_tlb_overflow_buffer, + free_pages((unsigned long)phys_to_virt(io_tlb_overflow_buffer), get_order(io_tlb_overflow)); free_pages((unsigned long)io_tlb_orig_addr, get_order(io_tlb_nslabs * sizeof(phys_addr_t))); @@ -328,7 +335,7 @@ void __init swiotlb_free(void) free_pages((unsigned long)phys_to_virt(io_tlb_start), get_order(io_tlb_nslabs << IO_TLB_SHIFT)); } else { - free_bootmem_late(__pa(io_tlb_overflow_buffer), + free_bootmem_late(io_tlb_overflow_buffer, PAGE_ALIGN(io_tlb_overflow)); free_bootmem_late(__pa(io_tlb_orig_addr), PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t))); @@ -698,7 +705,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, map = map_single(dev, phys, size, dir); if (!map) { swiotlb_full(dev, size, dir, 1); - map = io_tlb_overflow_buffer; + return phys_to_dma(dev, io_tlb_overflow_buffer); } dev_addr = swiotlb_virt_to_bus(dev, map); @@ -708,7 +715,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, */ if (!dma_capable(dev, dev_addr, size)) { swiotlb_tbl_unmap_single(dev, map, size, dir); - dev_addr = swiotlb_virt_to_bus(dev, io_tlb_overflow_buffer); + return phys_to_dma(dev, io_tlb_overflow_buffer); } return dev_addr; @@ -927,7 +934,7 @@ EXPORT_SYMBOL(swiotlb_sync_sg_for_device); int swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr) { - return (dma_addr == swiotlb_virt_to_bus(hwdev, io_tlb_overflow_buffer)); + return (dma_addr == phys_to_dma(hwdev, io_tlb_overflow_buffer)); } EXPORT_SYMBOL(swiotlb_dma_mapping_error); -- cgit v0.10.2