diff options
Diffstat (limited to 'arch/arc')
| -rw-r--r-- | arch/arc/mm/cache.c | 31 |
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(); |