}
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) {
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();