1 files changed, 21 insertions, 0 deletions

diff --git a/mm/cma.c b/mm/cma.c
index c17751c0dcaf..474c644a0dc6 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -32,6 +32,7 @@
 #include <linux/slab.h>
 #include <linux/log2.h>
 #include <linux/cma.h>
+#include <linux/highmem.h>
 
 struct cma {
         unsigned long   base_pfn;
@@ -163,6 +164,8 @@ int __init cma_declare_contiguous(phys_addr_t base,
                         bool fixed, struct cma **res_cma)
 {
         struct cma *cma;
+        phys_addr_t memblock_end = memblock_end_of_DRAM();
+        phys_addr_t highmem_start = __pa(high_memory);
         int ret = 0;
 
         pr_debug("%s(size %lx, base %08lx, limit %08lx alignment %08lx)\n",
@@ -196,6 +199,24 @@ int __init cma_declare_contiguous(phys_addr_t base,
         if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
                 return -EINVAL;
 
+        /*
+         * adjust limit to avoid crossing low/high memory boundary for
+         * automatically allocated regions
+         */
+        if (((limit == 0 || limit > memblock_end) &&
+             (memblock_end - size < highmem_start &&
+              memblock_end > highmem_start)) ||
+            (!fixed && limit > highmem_start && limit - size < highmem_start)) {
+                limit = highmem_start;
+        }
+
+        if (fixed && base < highmem_start && base+size > highmem_start) {
+                ret = -EINVAL;
+                pr_err("Region at %08lx defined on low/high memory boundary (%08lx)\n",
+                        (unsigned long)base, (unsigned long)highmem_start);
+                goto err;
+        }
+
         /* Reserve memory */
         if (base && fixed) {
                 if (memblock_is_region_reserved(base, size) ||