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>
On the Renesas RZ/Five SoC by default we want to configure 128MiB of memory
ranging from 0x58000000 as a non-cacheable + bufferable region in the PMA
and populate this region as PMA reserve DT node with shared DMA pool and
no-map flags set so that Linux drivers requesting any DMA'able memory go
through this region.
PMA node passed to the above stack:
reserved-memory {
#address-cells = <2>;
#size-cells = <2>;
ranges;
pma_resv0@58000000 {
compatible = "shared-dma-pool";
reg = <0x0 0x58000000 0x0 0x08000000>;
no-map;
linux,dma-default;
};
};
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
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 due to this reason IP blocks using DMA will fail.
The Andes AX45MP core has a Programmable Physical Memory Attributes (PMA)
block that allows dynamic adjustment of memory attributes in the runtime.
It contains a configurable amount of PMA entries implemented as CSR
registers to control the attributes of memory locations in interest.
Below are the memory attributes supported:
* Device, Non-bufferable
* Device, bufferable
* Memory, Non-cacheable, Non-bufferable
* Memory, Non-cacheable, Bufferable
* Memory, Write-back, No-allocate
* Memory, Write-back, Read-allocate
* Memory, Write-back, Write-allocate
* Memory, Write-back, Read and Write-allocate
More info about PMA (section 10.3):
Link: http://www.andestech.com/wp-content/uploads/AX45MP-1C-Rev.-5.0.0-Datasheet.pdf
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.
Example PMA region passed as a DT node from OpenSBI:
reserved-memory {
#address-cells = <2>;
#size-cells = <2>;
ranges;
pma_resv0@58000000 {
compatible = "shared-dma-pool";
reg = <0x0 0x58000000 0x0 0x08000000>;
no-map;
linux,dma-default;
};
};
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Renesas RZ/Five RISC-V SoC has Instruction local memory and Data local
memory (ILM & DLM) mapped between region 0x30000 - 0x4FFFF. When a
virtual address falls within this range, the MMU doesn't trigger a page
fault; it assumes the virtual address is a physical address which can
cause undesired behaviours for statically linked applications/libraries.
To avoid this, add the ILM/DLM memory regions to the root domain region
of the PMPU with permissions set to 0x0 for S/U modes so that any access
to these regions gets blocked and for M-mode we grant full access (R/W/X).
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Add compatible string for Andestech NCEPLIC100 found on Renesas RZ/Five SoC
which is equipped with AX45MP AndesCore.
While at it drop the comma after the sentinel as it does not make sense to
have a comma after a sentinel, as any new elements must be added before the
sentinel.
dts example (Single-core AX45MP):
soc: soc {
....
plic: interrupt-controller@12c00000 {
compatible = "renesas,r9a07g043-plic", "andestech,nceplic100";
#interrupt-cells = <2>;
#address-cells = <0>;
riscv,ndev = <511>;
interrupt-controller;
reg = <0x0 0x12c00000 0 0x400000>;
clocks = <&cpg CPG_MOD R9A07G043_NCEPLIC_ACLK>;
power-domains = <&cpg>;
resets = <&cpg R9A07G043_NCEPLIC_ARESETN>;
interrupts-extended = <&cpu0_intc 11 &cpu0_intc 9>;
};
....
};
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
It makes sense to use fdt_match_node() instead of fdt_find_match()
in fw_platform_lookup_special() as we already have the start offset
to search from.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
