Make UART4 the default UART for kernel messages

[linux-beck.git] / lib / swiotlb.c

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 22e13a0e19d76a2b704edab2464f0c2a0e57783f..ad1d2962d129cb7ea673edc0bb02e753529f9289 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
@@ -106,8 +106,12 @@ 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;
 }
@@ -541,8 +545,15 @@ static phys_addr_t
 map_single(struct device *hwdev, phys_addr_t phys, size_t size,
           enum dma_data_direction dir)
 {
-       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);
 }
 
@@ -707,6 +718,9 @@ 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.
@@ -749,7 +763,7 @@ 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);
@@ -888,7 +902,7 @@ 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);