6 files changed, 212 insertions, 95 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index a314e663d517..7e70ab13e191 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -78,13 +78,17 @@ config SCHEDSTATS
           this adds.
 
 config DEBUG_SLAB
-        bool "Debug memory allocations"
+        bool "Debug slab memory allocations"
         depends on DEBUG_KERNEL && SLAB
         help
           Say Y here to have the kernel do limited verification on memory
           allocation as well as poisoning memory on free to catch use of freed
           memory. This can make kmalloc/kfree-intensive workloads much slower.
 
+config DEBUG_SLAB_LEAK
+        bool "Memory leak debugging"
+        depends on DEBUG_SLAB
+
 config DEBUG_PREEMPT
         bool "Debug preemptible kernel"
         depends on DEBUG_KERNEL && PREEMPT
@@ -195,6 +199,16 @@ config FRAME_POINTER
           some architectures or if you use external debuggers.
           If you don't debug the kernel, you can say N.
 
+config UNWIND_INFO
+        bool "Compile the kernel with frame unwind information"
+        depends on !IA64
+        depends on !MODULES || !(MIPS || PARISC || PPC || SUPERH || SPARC64 || V850)
+        help
+          If you say Y here the resulting kernel image will be slightly larger
+          but not slower, and it will give very useful debugging information.
+          If you don't debug the kernel, you can say N, but we may not be able
+          to solve problems without frame unwind information or frame pointers.
+
 config FORCED_INLINING
         bool "Force gcc to inline functions marked 'inline'"
         depends on DEBUG_KERNEL
diff --git a/lib/Makefile b/lib/Makefile
index 648b2c1242fd..f827e3c24ec0 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -7,6 +7,8 @@ lib-y := errno.o ctype.o string.o vsprintf.o cmdline.o \
          idr.o div64.o int_sqrt.o bitmap.o extable.o prio_tree.o \
          sha1.o
 
+lib-$(CONFIG_SMP) += cpumask.o
+
 lib-y   += kobject.o kref.o kobject_uevent.o klist.o
 
 obj-y += sort.o parser.o halfmd4.o iomap_copy.o
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 48e708381d44..8acab0e176ef 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -676,84 +676,143 @@ int bitmap_bitremap(int oldbit, const unsigned long *old,
 }
 EXPORT_SYMBOL(bitmap_bitremap);
 
-/**
- *      bitmap_find_free_region - find a contiguous aligned mem region
- *      @bitmap: an array of unsigned longs corresponding to the bitmap
- *      @bits: number of bits in the bitmap
- *      @order: region size to find (size is actually 1<<order)
+/*
+ * Common code for bitmap_*_region() routines.
+ *      bitmap: array of unsigned longs corresponding to the bitmap
+ *      pos: the beginning of the region
+ *      order: region size (log base 2 of number of bits)
+ *      reg_op: operation(s) to perform on that region of bitmap
  *
- * This is used to allocate a memory region from a bitmap.  The idea is
- * that the region has to be 1<<order sized and 1<<order aligned (this
- * makes the search algorithm much faster).
+ * Can set, verify and/or release a region of bits in a bitmap,
+ * depending on which combination of REG_OP_* flag bits is set.
  *
- * The region is marked as set bits in the bitmap if a free one is
- * found.
+ * A region of a bitmap is a sequence of bits in the bitmap, of
+ * some size '1 << order' (a power of two), aligned to that same
+ * '1 << order' power of two.
  *
- * Returns either beginning of region or negative error
+ * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
+ * Returns 0 in all other cases and reg_ops.
  */
-int bitmap_find_free_region(unsigned long *bitmap, int bits, int order)
-{
-        unsigned long mask;
-        int pages = 1 << order;
-        int i;
 
-        if(pages > BITS_PER_LONG)
-                return -EINVAL;
+enum {
+        REG_OP_ISFREE,          /* true if region is all zero bits */
+        REG_OP_ALLOC,           /* set all bits in region */
+        REG_OP_RELEASE,         /* clear all bits in region */
+};
 
-        /* make a mask of the order */
-        mask = (1ul << (pages - 1));
+static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op)
+{
+        int nbits_reg;          /* number of bits in region */
+        int index;              /* index first long of region in bitmap */
+        int offset;             /* bit offset region in bitmap[index] */
+        int nlongs_reg;         /* num longs spanned by region in bitmap */
+        int nbitsinlong;        /* num bits of region in each spanned long */
+        unsigned long mask;     /* bitmask for one long of region */
+        int i;                  /* scans bitmap by longs */
+        int ret = 0;            /* return value */
+
+        /*
+         * Either nlongs_reg == 1 (for small orders that fit in one long)
+         * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
+         */
+        nbits_reg = 1 << order;
+        index = pos / BITS_PER_LONG;
+        offset = pos - (index * BITS_PER_LONG);
+        nlongs_reg = BITS_TO_LONGS(nbits_reg);
+        nbitsinlong = min(nbits_reg,  BITS_PER_LONG);
+
+        /*
+         * Can't do "mask = (1UL << nbitsinlong) - 1", as that
+         * overflows if nbitsinlong == BITS_PER_LONG.
+         */
+        mask = (1UL << (nbitsinlong - 1));
         mask += mask - 1;
+        mask <<= offset;
 
-        /* run up the bitmap pages bits at a time */
-        for (i = 0; i < bits; i += pages) {
-                int index = i/BITS_PER_LONG;
-                int offset = i - (index * BITS_PER_LONG);
-                if((bitmap[index] & (mask << offset)) == 0) {
-                        /* set region in bimap */
-                        bitmap[index] |= (mask << offset);
-                        return i;
+        switch (reg_op) {
+        case REG_OP_ISFREE:
+                for (i = 0; i < nlongs_reg; i++) {
+                        if (bitmap[index + i] & mask)
+                                goto done;
                 }
+                ret = 1;        /* all bits in region free (zero) */
+                break;
+
+        case REG_OP_ALLOC:
+                for (i = 0; i < nlongs_reg; i++)
+                        bitmap[index + i] |= mask;
+                break;
+
+        case REG_OP_RELEASE:
+                for (i = 0; i < nlongs_reg; i++)
+                        bitmap[index + i] &= ~mask;
+                break;
         }
-        return -ENOMEM;
+done:
+        return ret;
+}
+
+/**
+ * bitmap_find_free_region - find a contiguous aligned mem region
+ *      @bitmap: array of unsigned longs corresponding to the bitmap
+ *      @bits: number of bits in the bitmap
+ *      @order: region size (log base 2 of number of bits) to find
+ *
+ * Find a region of free (zero) bits in a @bitmap of @bits bits and
+ * allocate them (set them to one).  Only consider regions of length
+ * a power (@order) of two, aligned to that power of two, which
+ * makes the search algorithm much faster.
+ *
+ * Return the bit offset in bitmap of the allocated region,
+ * or -errno on failure.
+ */
+int bitmap_find_free_region(unsigned long *bitmap, int bits, int order)
+{
+        int pos;                /* scans bitmap by regions of size order */
+
+        for (pos = 0; pos < bits; pos += (1 << order))
+                if (__reg_op(bitmap, pos, order, REG_OP_ISFREE))
+                        break;
+        if (pos == bits)
+                return -ENOMEM;
+        __reg_op(bitmap, pos, order, REG_OP_ALLOC);
+        return pos;
 }
 EXPORT_SYMBOL(bitmap_find_free_region);
 
 /**
- *      bitmap_release_region - release allocated bitmap region
- *      @bitmap: a pointer to the bitmap
- *      @pos: the beginning of the region
- *      @order: the order of the bits to release (number is 1<<order)
+ * bitmap_release_region - release allocated bitmap region
+ *      @bitmap: array of unsigned longs corresponding to the bitmap
+ *      @pos: beginning of bit region to release
+ *      @order: region size (log base 2 of number of bits) to release
  *
  * This is the complement to __bitmap_find_free_region and releases
  * the found region (by clearing it in the bitmap).
+ *
+ * No return value.
  */
 void bitmap_release_region(unsigned long *bitmap, int pos, int order)
 {
-        int pages = 1 << order;
-        unsigned long mask = (1ul << (pages - 1));
-        int index = pos/BITS_PER_LONG;
-        int offset = pos - (index * BITS_PER_LONG);
-        mask += mask - 1;
-        bitmap[index] &= ~(mask << offset);
+        __reg_op(bitmap, pos, order, REG_OP_RELEASE);
 }
 EXPORT_SYMBOL(bitmap_release_region);
 
+/**
+ * bitmap_allocate_region - allocate bitmap region
+ *      @bitmap: array of unsigned longs corresponding to the bitmap
+ *      @pos: beginning of bit region to allocate
+ *      @order: region size (log base 2 of number of bits) to allocate
+ *
+ * Allocate (set bits in) a specified region of a bitmap.
+ *
+ * Return 0 on success, or -EBUSY if specified region wasn't
+ * free (not all bits were zero).
+ */
 int bitmap_allocate_region(unsigned long *bitmap, int pos, int order)
 {
-        int pages = 1 << order;
-        unsigned long mask = (1ul << (pages - 1));
-        int index = pos/BITS_PER_LONG;
-        int offset = pos - (index * BITS_PER_LONG);
-
-        /* We don't do regions of pages > BITS_PER_LONG.  The
-         * algorithm would be a simple look for multiple zeros in the
-         * array, but there's no driver today that needs this.  If you
-         * trip this BUG(), you get to code it... */
-        BUG_ON(pages > BITS_PER_LONG);
-        mask += mask - 1;
-        if (bitmap[index] & (mask << offset))
+        if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
                 return -EBUSY;
-        bitmap[index] |= (mask << offset);
+        __reg_op(bitmap, pos, order, REG_OP_ALLOC);
         return 0;
 }
 EXPORT_SYMBOL(bitmap_allocate_region);
diff --git a/lib/cpumask.c b/lib/cpumask.c
new file mode 100644
index 000000000000..3a67dc5ada7d
--- /dev/null
+++ b/lib/cpumask.c
@@ -0,0 +1,45 @@
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/cpumask.h>
+#include <linux/module.h>
+
+int __first_cpu(const cpumask_t *srcp)
+{
+        return min_t(int, NR_CPUS, find_first_bit(srcp->bits, NR_CPUS));
+}
+EXPORT_SYMBOL(__first_cpu);
+
+int __next_cpu(int n, const cpumask_t *srcp)
+{
+        return min_t(int, NR_CPUS, find_next_bit(srcp->bits, NR_CPUS, n+1));
+}
+EXPORT_SYMBOL(__next_cpu);
+
+/*
+ * Find the highest possible smp_processor_id()
+ *
+ * Note: if we're prepared to assume that cpu_possible_map never changes
+ * (reasonable) then this function should cache its return value.
+ */
+int highest_possible_processor_id(void)
+{
+        unsigned int cpu;
+        unsigned highest = 0;
+
+        for_each_cpu_mask(cpu, cpu_possible_map)
+                highest = cpu;
+        return highest;
+}
+EXPORT_SYMBOL(highest_possible_processor_id);
+
+int __any_online_cpu(const cpumask_t *mask)
+{
+        int cpu;
+
+        for_each_cpu_mask(cpu, *mask) {
+                if (cpu_online(cpu))
+                        break;
+        }
+        return cpu;
+}
+EXPORT_SYMBOL(__any_online_cpu);
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 1e5b17dc7e3d..7097bb239e40 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -37,7 +37,6 @@
 #else
 #define RADIX_TREE_MAP_SHIFT    3       /* For more stressful testing */
 #endif
-#define RADIX_TREE_TAGS         2
 
 #define RADIX_TREE_MAP_SIZE     (1UL << RADIX_TREE_MAP_SHIFT)
 #define RADIX_TREE_MAP_MASK     (RADIX_TREE_MAP_SIZE-1)
@@ -48,7 +47,7 @@
 struct radix_tree_node {
         unsigned int    count;
         void            *slots[RADIX_TREE_MAP_SIZE];
-        unsigned long   tags[RADIX_TREE_TAGS][RADIX_TREE_TAG_LONGS];
+        unsigned long   tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS];
 };
 
 struct radix_tree_path {
@@ -135,17 +134,20 @@ out:
         return ret;
 }
 
-static inline void tag_set(struct radix_tree_node *node, int tag, int offset)
+static inline void tag_set(struct radix_tree_node *node, unsigned int tag,
+                int offset)
 {
         __set_bit(offset, node->tags[tag]);
 }
 
-static inline void tag_clear(struct radix_tree_node *node, int tag, int offset)
+static inline void tag_clear(struct radix_tree_node *node, unsigned int tag,
+                int offset)
 {
         __clear_bit(offset, node->tags[tag]);
 }
 
-static inline int tag_get(struct radix_tree_node *node, int tag, int offset)
+static inline int tag_get(struct radix_tree_node *node, unsigned int tag,
+                int offset)
 {
         return test_bit(offset, node->tags[tag]);
 }
@@ -154,7 +156,7 @@ static inline int tag_get(struct radix_tree_node *node, int tag, int offset)
  * Returns 1 if any slot in the node has this tag set.
  * Otherwise returns 0.
  */
-static inline int any_tag_set(struct radix_tree_node *node, int tag)
+static inline int any_tag_set(struct radix_tree_node *node, unsigned int tag)
 {
         int idx;
         for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
@@ -180,7 +182,7 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index)
 {
         struct radix_tree_node *node;
         unsigned int height;
-        char tags[RADIX_TREE_TAGS];
+        char tags[RADIX_TREE_MAX_TAGS];
         int tag;
 
         /* Figure out what the height should be.  */
@@ -197,7 +199,7 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index)
          * Prepare the tag status of the top-level node for propagation
          * into the newly-pushed top-level node(s)
          */
-        for (tag = 0; tag < RADIX_TREE_TAGS; tag++) {
+        for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
                 tags[tag] = 0;
                 if (any_tag_set(root->rnode, tag))
                         tags[tag] = 1;
@@ -211,7 +213,7 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index)
                 node->slots[0] = root->rnode;
 
                 /* Propagate the aggregated tag info into the new root */
-                for (tag = 0; tag < RADIX_TREE_TAGS; tag++) {
+                for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
                         if (tags[tag])
                                 tag_set(node, tag, 0);
                 }
@@ -349,14 +351,15 @@ EXPORT_SYMBOL(radix_tree_lookup);
  *      @index:         index key
  *      @tag:           tag index
  *
- *      Set the search tag corresponging to @index in the radix tree.  From
+ *      Set the search tag (which must be < RADIX_TREE_MAX_TAGS)
+ *      corresponding to @index in the radix tree.  From
  *      the root all the way down to the leaf node.
  *
  *      Returns the address of the tagged item.   Setting a tag on a not-present
  *      item is a bug.
  */
 void *radix_tree_tag_set(struct radix_tree_root *root,
-                        unsigned long index, int tag)
+                        unsigned long index, unsigned int tag)
 {
         unsigned int height, shift;
         struct radix_tree_node *slot;
@@ -390,7 +393,8 @@ EXPORT_SYMBOL(radix_tree_tag_set);
  *      @index:         index key
  *      @tag:           tag index
  *
- *      Clear the search tag corresponging to @index in the radix tree.  If
+ *      Clear the search tag (which must be < RADIX_TREE_MAX_TAGS)
+ *      corresponding to @index in the radix tree.  If
  *      this causes the leaf node to have no tags set then clear the tag in the
  *      next-to-leaf node, etc.
  *
@@ -398,7 +402,7 @@ EXPORT_SYMBOL(radix_tree_tag_set);
  *      has the same return value and semantics as radix_tree_lookup().
  */
 void *radix_tree_tag_clear(struct radix_tree_root *root,
-                        unsigned long index, int tag)
+                        unsigned long index, unsigned int tag)
 {
         struct radix_tree_path path[RADIX_TREE_MAX_PATH], *pathp = path;
         struct radix_tree_node *slot;
@@ -450,7 +454,7 @@ EXPORT_SYMBOL(radix_tree_tag_clear);
  * radix_tree_tag_get - get a tag on a radix tree node
  * @root:               radix tree root
  * @index:              index key
- * @tag:                tag index
+ * @tag:                tag index (< RADIX_TREE_MAX_TAGS)
  *
  * Return values:
  *
@@ -459,7 +463,7 @@ EXPORT_SYMBOL(radix_tree_tag_clear);
  * -1: tag present, unset
  */
 int radix_tree_tag_get(struct radix_tree_root *root,
-                        unsigned long index, int tag)
+                        unsigned long index, unsigned int tag)
 {
         unsigned int height, shift;
         struct radix_tree_node *slot;
@@ -592,7 +596,7 @@ EXPORT_SYMBOL(radix_tree_gang_lookup);
  */
 static unsigned int
 __lookup_tag(struct radix_tree_root *root, void **results, unsigned long index,
-        unsigned int max_items, unsigned long *next_index, int tag)
+        unsigned int max_items, unsigned long *next_index, unsigned int tag)
 {
         unsigned int nr_found = 0;
         unsigned int shift;
@@ -646,7 +650,7 @@ out:
  *      @results:       where the results of the lookup are placed
  *      @first_index:   start the lookup from this key
  *      @max_items:     place up to this many items at *results
- *      @tag:           the tag index
+ *      @tag:           the tag index (< RADIX_TREE_MAX_TAGS)
  *
  *      Performs an index-ascending scan of the tree for present items which
  *      have the tag indexed by @tag set.  Places the items at *@results and
@@ -654,7 +658,8 @@ out:
  */
 unsigned int
 radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
-                unsigned long first_index, unsigned int max_items, int tag)
+                unsigned long first_index, unsigned int max_items,
+                unsigned int tag)
 {
         const unsigned long max_index = radix_tree_maxindex(root->height);
         unsigned long cur_index = first_index;
@@ -716,7 +721,7 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
         struct radix_tree_node *slot;
         unsigned int height, shift;
         void *ret = NULL;
-        char tags[RADIX_TREE_TAGS];
+        char tags[RADIX_TREE_MAX_TAGS];
         int nr_cleared_tags;
         int tag;
         int offset;
@@ -751,7 +756,7 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
          * Clear all tags associated with the just-deleted item
          */
         nr_cleared_tags = 0;
-        for (tag = 0; tag < RADIX_TREE_TAGS; tag++) {
+        for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
                 tags[tag] = 1;
                 if (tag_get(pathp->node, tag, pathp->offset)) {
                         tag_clear(pathp->node, tag, pathp->offset);
@@ -763,7 +768,7 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
         }
 
         for (pathp--; nr_cleared_tags && pathp->node; pathp--) {
-                for (tag = 0; tag < RADIX_TREE_TAGS; tag++) {
+                for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
                         if (tags[tag])
                                 continue;
 
@@ -801,7 +806,7 @@ EXPORT_SYMBOL(radix_tree_delete);
  *      @root:          radix tree root
  *      @tag:           tag to test
  */
-int radix_tree_tagged(struct radix_tree_root *root, int tag)
+int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag)
 {
         struct radix_tree_node *rnode;
         rnode = root->rnode;
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 0af497b6b9a8..10625785eefd 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -296,8 +296,7 @@ map_single(struct device *hwdev, char *buffer, size_t size, int dir)
         else
                 stride = 1;
 
-        if (!nslots)
-                BUG();
+        BUG_ON(!nslots);
 
         /*
          * Find suitable number of IO TLB entries size that will fit this
@@ -416,14 +415,14 @@ sync_single(struct device *hwdev, char *dma_addr, size_t size,
         case SYNC_FOR_CPU:
                 if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
                         memcpy(buffer, dma_addr, size);
-                else if (dir != DMA_TO_DEVICE)
-                        BUG();
+                else
+                        BUG_ON(dir != DMA_TO_DEVICE);
                 break;
         case SYNC_FOR_DEVICE:
                 if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
                         memcpy(dma_addr, buffer, size);
-                else if (dir != DMA_FROM_DEVICE)
-                        BUG();
+                else
+                        BUG_ON(dir != DMA_FROM_DEVICE);
                 break;
         default:
                 BUG();
@@ -529,8 +528,7 @@ swiotlb_map_single(struct device *hwdev, void *ptr, size_t size, int dir)
         unsigned long dev_addr = virt_to_phys(ptr);
         void *map;
 
-        if (dir == DMA_NONE)
-                BUG();
+        BUG_ON(dir == DMA_NONE);
         /*
          * If the pointer passed in happens to be in the device's DMA window,
          * we can safely return the device addr and not worry about bounce
@@ -592,8 +590,7 @@ swiotlb_unmap_single(struct device *hwdev, dma_addr_t dev_addr, size_t size,
 {
         char *dma_addr = phys_to_virt(dev_addr);
 
-        if (dir == DMA_NONE)
-                BUG();
+        BUG_ON(dir == DMA_NONE);
         if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
                 unmap_single(hwdev, dma_addr, size, dir);
         else if (dir == DMA_FROM_DEVICE)
@@ -616,8 +613,7 @@ swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
 {
         char *dma_addr = phys_to_virt(dev_addr);
 
-        if (dir == DMA_NONE)
-                BUG();
+        BUG_ON(dir == DMA_NONE);
         if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
                 sync_single(hwdev, dma_addr, size, dir, target);
         else if (dir == DMA_FROM_DEVICE)
@@ -648,8 +644,7 @@ swiotlb_sync_single_range(struct device *hwdev, dma_addr_t dev_addr,
 {
         char *dma_addr = phys_to_virt(dev_addr) + offset;
 
-        if (dir == DMA_NONE)
-                BUG();
+        BUG_ON(dir == DMA_NONE);
         if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
                 sync_single(hwdev, dma_addr, size, dir, target);
         else if (dir == DMA_FROM_DEVICE)
@@ -696,8 +691,7 @@ swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
         unsigned long dev_addr;
         int i;
 
-        if (dir == DMA_NONE)
-                BUG();
+        BUG_ON(dir == DMA_NONE);
 
         for (i = 0; i < nelems; i++, sg++) {
                 addr = SG_ENT_VIRT_ADDRESS(sg);
@@ -730,8 +724,7 @@ swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
 {
         int i;
 
-        if (dir == DMA_NONE)
-                BUG();
+        BUG_ON(dir == DMA_NONE);
 
         for (i = 0; i < nelems; i++, sg++)
                 if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
@@ -753,8 +746,7 @@ swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sg,
 {
         int i;
 
-        if (dir == DMA_NONE)
-                BUG();
+        BUG_ON(dir == DMA_NONE);
 
         for (i = 0; i < nelems; i++, sg++)
                 if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))