1 files changed, 16 insertions, 15 deletions

diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index 4135abec3fb0..63e6e6504699 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -113,10 +113,24 @@ static void read_decode_cache_bcr_arcv2(int cpu)
         }
 
         READ_BCR(ARC_REG_CLUSTER_BCR, cbcr);
-        if (cbcr.c)
+        if (cbcr.c) {
                 ioc_exists = 1;
-        else
+
+                /*
+                 * As for today we don't support both IOC and ZONE_HIGHMEM enabled
+                 * simultaneously. This happens because as of today IOC aperture covers
+                 * only ZONE_NORMAL (low mem) and any dma transactions outside this
+                 * region won't be HW coherent.
+                 * If we want to use both IOC and ZONE_HIGHMEM we can use
+                 * bounce_buffer to handle dma transactions to HIGHMEM.
+                 * Also it is possible to modify dma_direct cache ops or increase IOC
+                 * aperture size if we are planning to use HIGHMEM without PAE.
+                 */
+                if (IS_ENABLED(CONFIG_HIGHMEM) || is_pae40_enabled())
+                        ioc_enable = 0;
+        } else {
                 ioc_enable = 0;
+        }
 
         /* HS 2.0 didn't have AUX_VOL */
         if (cpuinfo_arc700[cpu].core.family > 0x51) {
@@ -1158,19 +1172,6 @@ noinline void __init arc_ioc_setup(void)
         if (!ioc_enable)
                 return;
 
-        /*
-         * As for today we don't support both IOC and ZONE_HIGHMEM enabled
-         * simultaneously. This happens because as of today IOC aperture covers
-         * only ZONE_NORMAL (low mem) and any dma transactions outside this
-         * region won't be HW coherent.
-         * If we want to use both IOC and ZONE_HIGHMEM we can use
-         * bounce_buffer to handle dma transactions to HIGHMEM.
-         * Also it is possible to modify dma_direct cache ops or increase IOC
-         * aperture size if we are planning to use HIGHMEM without PAE.
-         */
-        if (IS_ENABLED(CONFIG_HIGHMEM))
-                panic("IOC and HIGHMEM can't be used simultaneously");
-
         /* Flush + invalidate + disable L1 dcache */
         __dc_disable();