3 files changed, 18 insertions, 4 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index b0f239e443bc..1e3fd3e3436a 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -545,6 +545,16 @@ config DEBUG_SG
 
           If unsure, say N.
 
+config DEBUG_NOTIFIERS
+        bool "Debug notifier call chains"
+        depends on DEBUG_KERNEL
+        help
+          Enable this to turn on sanity checking for notifier call chains.
+          This is most useful for kernel developers to make sure that
+          modules properly unregister themselves from notifier chains.
+          This is a relatively cheap check but if you care about maximum
+          performance, say N.
+
 config FRAME_POINTER
         bool "Compile the kernel with frame pointers"
         depends on DEBUG_KERNEL && \
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index 8d2688ff1352..b7b449dafbe5 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -395,7 +395,7 @@ void sg_miter_stop(struct sg_mapping_iter *miter)
                         WARN_ON(!irqs_disabled());
                         kunmap_atomic(miter->addr, KM_BIO_SRC_IRQ);
                 } else
-                        kunmap(miter->addr);
+                        kunmap(miter->page);
 
                 miter->page = NULL;
                 miter->addr = NULL;
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 78330c37a61b..5f6c629a924d 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -467,9 +467,13 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
         dma_addr_t dev_addr;
         void *ret;
         int order = get_order(size);
+        u64 dma_mask = DMA_32BIT_MASK;
+
+        if (hwdev && hwdev->coherent_dma_mask)
+                dma_mask = hwdev->coherent_dma_mask;
 
         ret = (void *)__get_free_pages(flags, order);
-        if (ret && address_needs_mapping(hwdev, virt_to_bus(ret), size)) {
+        if (ret && !is_buffer_dma_capable(dma_mask, virt_to_bus(ret), size)) {
                 /*
                  * The allocated memory isn't reachable by the device.
                  * Fall back on swiotlb_map_single().
@@ -493,9 +497,9 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
         dev_addr = virt_to_bus(ret);
 
         /* Confirm address can be DMA'd by device */
-        if (address_needs_mapping(hwdev, dev_addr, size)) {
+        if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
                 printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
-                       (unsigned long long)*hwdev->dma_mask,
+                       (unsigned long long)dma_mask,
                        (unsigned long long)dev_addr);
 
                 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */