From ff7204a74931fc67ed13d8febbc322a46833c1fa Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Mon, 15 Oct 2012 10:19:28 -0700 Subject: swiotlb: Make io_tlb_start a physical address instead of a virtual one This change replaces all references to the virtual address for io_tlb_start with references to the physical address io_tlb_end. The main advantage of replacing the virtual address with a physical address is that we can avoid having to do multiple translations from the virtual address to the physical one needed for testing an existing DMA address. Signed-off-by: Alexander Duyck Signed-off-by: Konrad Rzeszutek Wilk --- lib/swiotlb.c | 58 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 29 insertions(+), 29 deletions(-) (limited to 'lib/swiotlb.c') diff --git a/lib/swiotlb.c b/lib/swiotlb.c index c0cbfa1116c..8c4791f17ec 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -57,8 +57,7 @@ int swiotlb_force; * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this * API. */ -static char *io_tlb_start; -static phys_addr_t io_tlb_end; +static phys_addr_t io_tlb_start, io_tlb_end; /* * The number of IO TLB blocks (in groups of 64) between io_tlb_start and @@ -126,16 +125,15 @@ static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev, void swiotlb_print_info(void) { unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT; - phys_addr_t pstart; - unsigned char *vend; + unsigned char *vstart, *vend; - pstart = virt_to_phys(io_tlb_start); + vstart = phys_to_virt(io_tlb_start); vend = phys_to_virt(io_tlb_end); printk(KERN_INFO "software IO TLB [mem %#010llx-%#010llx] (%luMB) mapped at [%p-%p]\n", - (unsigned long long)pstart, + (unsigned long long)io_tlb_start, (unsigned long long)io_tlb_end, - bytes >> 20, io_tlb_start, vend - 1); + bytes >> 20, vstart, vend - 1); } void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) @@ -145,8 +143,8 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) bytes = nslabs << IO_TLB_SHIFT; io_tlb_nslabs = nslabs; - io_tlb_start = tlb; - io_tlb_end = __pa(io_tlb_start) + bytes; + io_tlb_start = __pa(tlb); + io_tlb_end = io_tlb_start + bytes; /* * Allocate and initialize the free list array. This array is used @@ -176,6 +174,7 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) static void __init swiotlb_init_with_default_size(size_t default_size, int verbose) { + unsigned char *vstart; unsigned long bytes; if (!io_tlb_nslabs) { @@ -188,11 +187,11 @@ swiotlb_init_with_default_size(size_t default_size, int verbose) /* * Get IO TLB memory from the low pages */ - io_tlb_start = alloc_bootmem_low_pages(PAGE_ALIGN(bytes)); - if (!io_tlb_start) + vstart = alloc_bootmem_low_pages(PAGE_ALIGN(bytes)); + if (!vstart) panic("Cannot allocate SWIOTLB buffer"); - swiotlb_init_with_tbl(io_tlb_start, io_tlb_nslabs, verbose); + swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose); } void __init @@ -210,6 +209,7 @@ int swiotlb_late_init_with_default_size(size_t default_size) { unsigned long bytes, req_nslabs = io_tlb_nslabs; + unsigned char *vstart = NULL; unsigned int order; int rc = 0; @@ -226,14 +226,14 @@ 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 = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, - order); - if (io_tlb_start) + vstart = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, + order); + if (vstart) break; order--; } - if (!io_tlb_start) { + if (!vstart) { io_tlb_nslabs = req_nslabs; return -ENOMEM; } @@ -242,9 +242,9 @@ swiotlb_late_init_with_default_size(size_t default_size) "for software IO TLB\n", (PAGE_SIZE << order) >> 20); io_tlb_nslabs = SLABS_PER_PAGE << order; } - rc = swiotlb_late_init_with_tbl(io_tlb_start, io_tlb_nslabs); + rc = swiotlb_late_init_with_tbl(vstart, io_tlb_nslabs); if (rc) - free_pages((unsigned long)io_tlb_start, order); + free_pages((unsigned long)vstart, order); return rc; } @@ -256,10 +256,10 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) bytes = nslabs << IO_TLB_SHIFT; io_tlb_nslabs = nslabs; - io_tlb_start = tlb; - io_tlb_end = virt_to_phys(io_tlb_start) + bytes; + io_tlb_start = virt_to_phys(tlb); + io_tlb_end = io_tlb_start + bytes; - memset(io_tlb_start, 0, bytes); + memset(tlb, 0, bytes); /* * Allocate and initialize the free list array. This array is used @@ -308,7 +308,7 @@ cleanup3: io_tlb_list = NULL; cleanup2: io_tlb_end = 0; - io_tlb_start = NULL; + io_tlb_start = 0; io_tlb_nslabs = 0; return -ENOMEM; } @@ -325,7 +325,7 @@ void __init swiotlb_free(void) get_order(io_tlb_nslabs * sizeof(phys_addr_t))); free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs * sizeof(int))); - free_pages((unsigned long)io_tlb_start, + 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), @@ -334,7 +334,7 @@ void __init swiotlb_free(void) PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t))); free_bootmem_late(__pa(io_tlb_list), PAGE_ALIGN(io_tlb_nslabs * sizeof(int))); - free_bootmem_late(__pa(io_tlb_start), + free_bootmem_late(io_tlb_start, PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT)); } io_tlb_nslabs = 0; @@ -342,7 +342,7 @@ void __init swiotlb_free(void) static int is_swiotlb_buffer(phys_addr_t paddr) { - return paddr >= virt_to_phys(io_tlb_start) && paddr < io_tlb_end; + return paddr >= io_tlb_start && paddr < io_tlb_end; } /* @@ -455,7 +455,7 @@ void *swiotlb_tbl_map_single(struct device *hwdev, dma_addr_t tbl_dma_addr, io_tlb_list[i] = 0; for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && io_tlb_list[i]; i--) io_tlb_list[i] = ++count; - dma_addr = io_tlb_start + (index << IO_TLB_SHIFT); + dma_addr = (char *)phys_to_virt(io_tlb_start) + (index << IO_TLB_SHIFT); /* * Update the indices to avoid searching in the next @@ -499,7 +499,7 @@ static void * map_single(struct device *hwdev, phys_addr_t phys, size_t size, enum dma_data_direction dir) { - dma_addr_t start_dma_addr = swiotlb_virt_to_bus(hwdev, io_tlb_start); + dma_addr_t start_dma_addr = phys_to_dma(hwdev, io_tlb_start); return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, dir); } @@ -513,7 +513,7 @@ swiotlb_tbl_unmap_single(struct device *hwdev, char *dma_addr, size_t size, { unsigned long flags; int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; - int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT; + int index = (dma_addr - (char *)phys_to_virt(io_tlb_start)) >> IO_TLB_SHIFT; phys_addr_t phys = io_tlb_orig_addr[index]; /* @@ -554,7 +554,7 @@ swiotlb_tbl_sync_single(struct device *hwdev, char *dma_addr, size_t size, enum dma_data_direction dir, enum dma_sync_target target) { - int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT; + int index = (dma_addr - (char *)phys_to_virt(io_tlb_start)) >> IO_TLB_SHIFT; phys_addr_t phys = io_tlb_orig_addr[index]; phys += ((unsigned long)dma_addr & ((1 << IO_TLB_SHIFT) - 1)); -- cgit v1.2.3