diff options
Diffstat (limited to 'arch/arc/mm/cache.c')
| -rw-r--r-- | arch/arc/mm/cache.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c index f2701c13a66b..4135abec3fb0 100644 --- a/arch/arc/mm/cache.c +++ b/arch/arc/mm/cache.c @@ -1145,6 +1145,20 @@ noinline void __init arc_ioc_setup(void) unsigned int ioc_base, mem_sz; /* + * If IOC was already enabled (due to bootloader) it technically needs to + * be reconfigured with aperture base,size corresponding to Linux memory map + * which will certainly be different than uboot's. But disabling and + * reenabling IOC when DMA might be potentially active is tricky business. + * To avoid random memory issues later, just panic here and ask user to + * upgrade bootloader to one which doesn't enable IOC + */ + if (read_aux_reg(ARC_REG_IO_COH_ENABLE) & ARC_IO_COH_ENABLE_BIT) + panic("IOC already enabled, please upgrade bootloader!\n"); + + 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 @@ -1187,8 +1201,8 @@ noinline void __init arc_ioc_setup(void) panic("IOC Aperture start must be aligned to the size of the aperture"); write_aux_reg(ARC_REG_IO_COH_AP0_BASE, ioc_base >> 12); - write_aux_reg(ARC_REG_IO_COH_PARTIAL, 1); - write_aux_reg(ARC_REG_IO_COH_ENABLE, 1); + write_aux_reg(ARC_REG_IO_COH_PARTIAL, ARC_IO_COH_PARTIAL_BIT); + write_aux_reg(ARC_REG_IO_COH_ENABLE, ARC_IO_COH_ENABLE_BIT); /* Re-enable L1 dcache */ __dc_enable(); @@ -1265,7 +1279,7 @@ void __init arc_cache_init_master(void) if (is_isa_arcv2() && l2_line_sz && !slc_enable) arc_slc_disable(); - if (is_isa_arcv2() && ioc_enable) + if (is_isa_arcv2() && ioc_exists) arc_ioc_setup(); if (is_isa_arcv2() && l2_line_sz && slc_enable) { @@ -1280,7 +1294,7 @@ void __init arc_cache_init_master(void) /* * In case of IOC (say IOC+SLC case), pointers above could still be set * but end up not being relevant as the first function in chain is not - * called at all for @dma_direct_ops + * called at all for devices using coherent DMA. * arch_sync_dma_for_cpu() -> dma_cache_*() -> __dma_cache_*() */ } |