Merge tag 'char-misc-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregk...

[mirror_ubuntu-zesty-kernel.git] / lib / swiotlb.c

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index cb1b54ee8527241de289ab66f34f9a0a1efa761f..975b8fc4f1e1143dcdd295731cf1fc18cf0561fe 100644 (file)
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -53,7 +53,7 @@
  */
 #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
 
-int swiotlb_force;
+enum swiotlb_force swiotlb_force;
 
 /*
  * Used to do a quick range check in swiotlb_tbl_unmap_single and
@@ -82,6 +82,12 @@ static phys_addr_t io_tlb_overflow_buffer;
 static unsigned int *io_tlb_list;
 static unsigned int io_tlb_index;
 
+/*
+ * Max segment that we can provide which (if pages are contingous) will
+ * not be bounced (unless SWIOTLB_FORCE is set).
+ */
+unsigned int max_segment;
+
 /*
  * We need to save away the original address corresponding to a mapped entry
  * for the sync operations.
@@ -106,8 +112,12 @@ setup_io_tlb_npages(char *str)
        }
        if (*str == ',')
                ++str;
-       if (!strcmp(str, "force"))
-               swiotlb_force = 1;
+       if (!strcmp(str, "force")) {
+               swiotlb_force = SWIOTLB_FORCE;
+       } else if (!strcmp(str, "noforce")) {
+               swiotlb_force = SWIOTLB_NO_FORCE;
+               io_tlb_nslabs = 1;
+       }
 
        return 0;
 }
@@ -120,6 +130,20 @@ unsigned long swiotlb_nr_tbl(void)
 }
 EXPORT_SYMBOL_GPL(swiotlb_nr_tbl);
 
+unsigned int swiotlb_max_segment(void)
+{
+       return max_segment;
+}
+EXPORT_SYMBOL_GPL(swiotlb_max_segment);
+
+void swiotlb_set_max_segment(unsigned int val)
+{
+       if (swiotlb_force == SWIOTLB_FORCE)
+               max_segment = 1;
+       else
+               max_segment = rounddown(val, PAGE_SIZE);
+}
+
 /* default to 64MB */
 #define IO_TLB_DEFAULT_SIZE (64UL<<20)
 unsigned long swiotlb_size_or_default(void)
@@ -201,6 +225,7 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
        if (verbose)
                swiotlb_print_info();
 
+       swiotlb_set_max_segment(io_tlb_nslabs << IO_TLB_SHIFT);
        return 0;
 }
 
@@ -279,6 +304,7 @@ swiotlb_late_init_with_default_size(size_t default_size)
        rc = swiotlb_late_init_with_tbl(vstart, io_tlb_nslabs);
        if (rc)
                free_pages((unsigned long)vstart, order);
+
        return rc;
 }
 
@@ -333,6 +359,8 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
 
        late_alloc = 1;
 
+       swiotlb_set_max_segment(io_tlb_nslabs << IO_TLB_SHIFT);
+
        return 0;
 
 cleanup4:
@@ -347,6 +375,7 @@ cleanup2:
        io_tlb_end = 0;
        io_tlb_start = 0;
        io_tlb_nslabs = 0;
+       max_segment = 0;
        return -ENOMEM;
 }
 
@@ -375,6 +404,7 @@ void __init swiotlb_free(void)
                                   PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
        }
        io_tlb_nslabs = 0;
+       max_segment = 0;
 }
 
 int is_swiotlb_buffer(phys_addr_t paddr)
@@ -543,8 +573,15 @@ static phys_addr_t
 map_single(struct device *hwdev, phys_addr_t phys, size_t size,
           enum dma_data_direction dir, unsigned long attrs)
 {
-       dma_addr_t start_dma_addr = phys_to_dma(hwdev, io_tlb_start);
+       dma_addr_t start_dma_addr;
 
+       if (swiotlb_force == SWIOTLB_NO_FORCE) {
+               dev_warn_ratelimited(hwdev, "Cannot do DMA to address %pa\n",
+                                    &phys);
+               return SWIOTLB_MAP_ERROR;
+       }
+
+       start_dma_addr = phys_to_dma(hwdev, io_tlb_start);
        return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size,
                                      dir, attrs);
 }
@@ -721,6 +758,9 @@ static void
 swiotlb_full(struct device *dev, size_t size, enum dma_data_direction dir,
             int do_panic)
 {
+       if (swiotlb_force == SWIOTLB_NO_FORCE)
+               return;
+
        /*
         * Ran out of IOMMU space for this operation. This is very bad.
         * Unfortunately the drivers cannot handle this operation properly.
@@ -763,7 +803,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
         * we can safely return the device addr and not worry about bounce
         * buffering it.
         */
-       if (dma_capable(dev, dev_addr, size) && !swiotlb_force)
+       if (dma_capable(dev, dev_addr, size) && swiotlb_force != SWIOTLB_FORCE)
                return dev_addr;
 
        trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force);
@@ -904,7 +944,7 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
                phys_addr_t paddr = sg_phys(sg);
                dma_addr_t dev_addr = phys_to_dma(hwdev, paddr);
 
-               if (swiotlb_force ||
+               if (swiotlb_force == SWIOTLB_FORCE ||
                    !dma_capable(hwdev, dev_addr, sg->length)) {
                        phys_addr_t map = map_single(hwdev, sg_phys(sg),
                                                     sg->length, dir, attrs);