I/O Coherence Port (IOCP) provides an AXI interface for connecting
external non-caching masters, such as DMA controllers. The accesses
from IOCP are coherent with D-Caches and L2 Cache.
IOCP is a specification option and is disabled on the Renesas RZ/Five
SoC (which is based on Andes AX45MP core) due to this reason IP blocks
using DMA will fail.
As a workaround for SoCs with IOCP disabled CMO needs to be handled by
software. Firstly OpenSBI configures the memory region as
"Memory, Non-cacheable, Bufferable" and passes this region as a global
shared dma pool as a DT node. With DMA_GLOBAL_POOL enabled all DMA
allocations happen from this region and synchronization callbacks are
implemented to synchronize when doing DMA transactions.
SBI_EXT_ANDES_IOCP_SW_WORKAROUND checks if the IOCP errata should be
applied to handle cache management.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Yu Chien Peter Lin <peterlin@andestech.com>
Add hart_start() and hart_stop() callbacks for the multi-core ae350
platform, it utilizes the ATCSMU to put the harts into power-gated
deep sleep mode. The programming sequence is stated as below:
1. Set the wakeup events to PCSm_WE
2. Set the sleep command to PCSm_CTL
3. Set the reset vector to HARTm_RESET_VECTOR_{LO|HI}
4. Write back and invalidate D-cache by executing the CCTL command L1D_WBINVAL_ALL
5. Disable I/D-cache by clearing mcache_ctl.{I|D}C_EN
6. Disable D-cache coherency by clearing mcache_ctl_.DC_COHEN
7. Wait for mcache_ctl.DC_COHSTA to be cleared to ensure the previous step is completed
8. Execute WFI
Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Anup Patel <anup@brainfault.org>