1 files changed, 35 insertions, 4 deletions

diff --git a/mm/cma.c b/mm/cma.c
index fde706e1284f..f8917629cbdd 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -33,6 +33,7 @@
 #include <linux/log2.h>
 #include <linux/cma.h>
 #include <linux/highmem.h>
+#include <linux/io.h>
 
 struct cma {
 	unsigned long	base_pfn;
@@ -63,6 +64,17 @@ static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order)
 	return (1UL << (align_order - cma->order_per_bit)) - 1;
 }
 
+static unsigned long cma_bitmap_aligned_offset(struct cma *cma, int align_order)
+{
+	unsigned int alignment;
+
+	if (align_order <= cma->order_per_bit)
+		return 0;
+	alignment = 1UL << (align_order - cma->order_per_bit);
+	return ALIGN(cma->base_pfn, alignment) -
+		(cma->base_pfn >> cma->order_per_bit);
+}
+
 static unsigned long cma_bitmap_maxno(struct cma *cma)
 {
 	return cma->count >> cma->order_per_bit;
@@ -215,9 +227,21 @@ int __init cma_declare_contiguous(phys_addr_t base,
 			bool fixed, struct cma **res_cma)
 {
 	phys_addr_t memblock_end = memblock_end_of_DRAM();
-	phys_addr_t highmem_start = __pa(high_memory);
+	phys_addr_t highmem_start;
 	int ret = 0;
 
+#ifdef CONFIG_X86
+	/*
+	 * high_memory isn't direct mapped memory so retrieving its physical
+	 * address isn't appropriate.  But it would be useful to check the
+	 * physical address of the highmem boundary so it's justfiable to get
+	 * the physical address from it.  On x86 there is a validation check for
+	 * this case, so the following workaround is needed to avoid it.
+	 */
+	highmem_start = __pa_nodebug(high_memory);
+#else
+	highmem_start = __pa(high_memory);
+#endif
 	pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n",
 		__func__, &size, &base, &limit, &alignment);
 
@@ -301,6 +325,11 @@ int __init cma_declare_contiguous(phys_addr_t base,
 			}
 		}
 
+		/*
+		 * kmemleak scans/reads tracked objects for pointers to other
+		 * objects but this address isn't mapped and accessible
+		 */
+		kmemleak_ignore(phys_to_virt(addr));
 		base = addr;
 	}
 
@@ -328,7 +357,7 @@ err:
  */
 struct page *cma_alloc(struct cma *cma, int count, unsigned int align)
 {
-	unsigned long mask, pfn, start = 0;
+	unsigned long mask, offset, pfn, start = 0;
 	unsigned long bitmap_maxno, bitmap_no, bitmap_count;
 	struct page *page = NULL;
 	int ret;
@@ -343,13 +372,15 @@ struct page *cma_alloc(struct cma *cma, int count, unsigned int align)
 		return NULL;
 
 	mask = cma_bitmap_aligned_mask(cma, align);
+	offset = cma_bitmap_aligned_offset(cma, align);
 	bitmap_maxno = cma_bitmap_maxno(cma);
 	bitmap_count = cma_bitmap_pages_to_bits(cma, count);
 
 	for (;;) {
 		mutex_lock(&cma->lock);
-		bitmap_no = bitmap_find_next_zero_area(cma->bitmap,
-				bitmap_maxno, start, bitmap_count, mask);
+		bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap,
+				bitmap_maxno, start, bitmap_count, mask,
+				offset);
 		if (bitmap_no >= bitmap_maxno) {
 			mutex_unlock(&cma->lock);
 			break;