Re: [PATCH v4 0/7] AX45MP: Add support to non-coherent DMA

Conor Dooley
2022-11-24T19:41:46Z

Hey!

On Thu, Nov 24, 2022 at 05:22:00PM +0000, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Hi All,
>
> On the Andes AX45MP core, cache coherency is a specification option so it
> may not be supported. In this case DMA will fail. To get around with this
> issue this patch series does the below:
>
> 1] 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. PMA
> regions are passed from the l2 node which are configured as
> non-cacheable + bufferable with the SBI call.
>
> l2cache: cache-controller@13400000 {
> ....
> andestech,pma-regions = <0x58000000 0x08000000
> (AX45MP_PMACFG_ETYP_NAPOT |
> AX45MP_PMACFG_MTYP_MEM_NON_CACHE_BUF)>;
> ....
> };
>
> 2] We provide callbacks to synchronize specific content between memory and
> cache.
>
> - arch_sync_dma_for_device()
> - arch_sync_dma_for_cpu()
>
> Below are the configs that are enabled:
>
> - DMA_GLOBAL_POOL
> - RISCV_DMA_NONCOHERENT
>
> 3] We reserve the shared DMA pool, so the DMA memory requests go through
> this pool:
>
> reserved-memory {
> #address-cells = <2>;
> #size-cells = <2>;
> ranges;
>
> reserved: linux,cma@58000000 {
> compatible = "shared-dma-pool";
> no-map;
> linux,dma-default;
> reg = <0x0 0x58000000 0x0 0x08000000>;
> };
> };
>
>
> Below is the L2 cache DT node:
>
> l2cache: cache-controller@13400000 {
> compatible = "andestech,ax45mp-cache", "cache";
> cache-size = <0x40000>;
> cache-line-size = <64>;
> cache-sets = <1024>;
> cache-unified;
> reg = <0x0 0x13400000 0x0 0x100000>;
> andestech,pma-regions = <0x0 0x58000000 0x0 0x08000000 0x0
> (AX45MP_PMACFG_ETYP_NAPOT |
> AX45MP_PMACFG_MTYP_MEM_NON_CACHE_BUF)>;
> interrupts = <SOC_PERIPHERAL_IRQ(476, IRQ_TYPE_LEVEL_HIGH)>;
> };
>
> Due to the above approach custom SBI calls have been implemented. The
> above implementation is in preparation for adding support for Renesas
> RZ/Five SoC which uses the AX45MP core. As with the above approach the
> kernel image might not be generic so that it can be used on other
> platforms.
>
> OpenSBI implementation isn't upstreamed yet, public repo for access is
> available at [0].
>
> [0] https://github.com/renesas-rz/rz_opensbi/tree/work/OpenSBI-PMA
>
> Note,
> - This series requires testing on Cores with zibcom and T-Head SoCs
> - Ive used GCC 9.4.0 for compilation

Just dumping the following, which I saw with gcc 12.1 & binutils 2.39
while building allmodconfig. Perhaps it is worth you upgrading to a
recent toolchain for testing purposes. FWIW, I applied your patches on
top of 20221122.

/stuff/linux/arch/riscv/mm/dma-noncoherent.c: Assembler messages:
/stuff/linux/arch/riscv/mm/dma-noncoherent.c:62: Error: attempt to move .org backwards
/stuff/linux/arch/riscv/mm/dma-noncoherent.c:66: Error: attempt to move .org backwards
/stuff/linux/arch/riscv/mm/dma-noncoherent.c:84: Error: attempt to move .org backwards
/stuff/linux/arch/riscv/mm/dma-noncoherent.c:96: Error: attempt to move .org backwards

In file included from /stuff/linux/arch/riscv/errata/andes/errata.c:16:
/stuff/linux/arch/riscv/errata/andes/errata.c: In function 'is_auipc_insn':
/stuff/linux/arch/riscv/errata/andes/errata.c:25:34: error: 'MASK_AUIPC' undeclared (first use in this function)
25 | DECLARE_INSN(auipc, MATCH_AUIPC, MASK_AUIPC)
| ^~~~~~~~~~
/stuff/linux/arch/riscv/include/asm/parse_asm.h:175:25: note: in definition of macro 'DECLARE_INSN'
175 | return (insn & (INSN_MASK)) == (INSN_MATCH); \
| ^~~~~~~~~
/stuff/linux/arch/riscv/errata/andes/errata.c:25:34: note: each undeclared identifier is reported only once for each function it appears in
25 | DECLARE_INSN(auipc, MATCH_AUIPC, MASK_AUIPC)
| ^~~~~~~~~~
/stuff/linux/arch/riscv/include/asm/parse_asm.h:175:25: note: in definition of macro 'DECLARE_INSN'
175 | return (insn & (INSN_MASK)) == (INSN_MATCH); \
| ^~~~~~~~~
/stuff/linux/arch/riscv/errata/andes/errata.c:25:21: error: 'MATCH_AUIPC' undeclared (first use in this function); did you mean 'OPC_AUIPC'?
25 | DECLARE_INSN(auipc, MATCH_AUIPC, MASK_AUIPC)
| ^~~~~~~~~~~
/stuff/linux/arch/riscv/include/asm/parse_asm.h:175:41: note: in definition of macro 'DECLARE_INSN'
175 | return (insn & (INSN_MASK)) == (INSN_MATCH); \
| ^~~~~~~~~~
/stuff/linux/arch/riscv/errata/andes/errata.c: In function 'riscv_alternative_fix_auipc_jalr':
/stuff/linux/arch/riscv/errata/andes/errata.c:64:23: error: implicit declaration of function 'EXTRACT_RD_REG' [-Werror=implicit-function-declaration]
64 | rd1 = EXTRACT_RD_REG(*(alt_ptr + i));
| ^~~~~~~~~~~~~~
/stuff/linux/arch/riscv/errata/andes/errata.c:69:24: error: implicit declaration of function 'EXTRACT_UTYPE_IMM'; did you mean 'EXTRACT_BTYPE_IMM'? [-Werror=implicit-function-declaration]
69 | imm1 = EXTRACT_UTYPE_IMM(*(alt_ptr + i));
| ^~~~~~~~~~~~~~~~~
| EXTRACT_BTYPE_IMM
/stuff/linux/arch/riscv/errata/andes/errata.c:78:30: error: 'U_IMM_31_12_MASK' undeclared (first use in this function); did you mean 'J_IMM_19_12_MASK'?
78 | call[0] &= ~(U_IMM_31_12_MASK);
| ^~~~~~~~~~~~~~~~
| J_IMM_19_12_MASK
/stuff/linux/arch/riscv/errata/andes/errata.c: In function 'is_auipc_insn':
/stuff/linux/arch/riscv/include/asm/parse_asm.h:176:1: error: control reaches end of non-void function [-Werror=return-type]
176 | }
| ^
/stuff/linux/arch/riscv/errata/andes/errata.c:25:1: note: in expansion of macro 'DECLARE_INSN'
25 | DECLARE_INSN(auipc, MATCH_AUIPC, MASK_AUIPC)
| ^~~~~~~~~~~~
cc1: all warnings being treated as errors

> - Tested all the IP blocks on RZ/Five which use DMA
>
> RFC v3 -> v4
> * Implemented ALTERNATIVE_3() macro
> * Now using runtime patching mechanism instead of compile time config
> * Added Andes CMO as and errata
> * Fixed comments pointed by Geert
>
> RFC v2-> RFC v3
> * Fixed review comments pointed by Conor
> * Move DT binding into cache folder
> * Fixed DT binding check issue
> * Added andestech,ax45mp-cache.h header file
> * Now passing the flags for the PMA setup as part of andestech,pma-regions
> property.
> * Added andestech,inst/data-prefetch and andestech,tag/data-ram-ctl
> properties to configure the L2 cache.
> * Registered the cache driver as platform driver
>
> RFC v1-> RFC v2
> * Moved out the code from arc/riscv to drivers/soc/renesas
> * Now handling the PMA setup as part of the L2 cache
> * Now making use of dma-noncoherent.c instead SoC specific implementation.
> * Dropped arch_dma_alloc() and arch_dma_free()
> * Switched to RISCV_DMA_NONCOHERENT
> * Included DT binding doc
>
> RFC v2: https://patchwork.kernel.org/project/linux-renesas-soc/cover/20221003223222.448551-1-prabhakar.mahadev-lad.rj@bp.renesas.com/
> RFC v1: https://patchwork.kernel.org/project/linux-renesas-soc/cover/20220906102154.32526-1-prabhakar.mahadev-lad.rj@bp.renesas.com/
>
> Cheers,
> Prabhakar
>
> Lad Prabhakar (7):
> riscv: asm: alternative-macros: Introduce ALTERNATIVE_3() macro
> riscv: asm: vendorid_list: Add Andes Technology to the vendors list
> riscv: errata: Add Andes alternative ports
> riscv: errata: andes: Fix auipc-jalr addresses in patched alternatives
> riscv: mm: dma-noncoherent: Pass direction and operation to
> ALT_CMO_OP()
> dt-bindings: cache: r9a07g043f-l2-cache: Add DT binding documentation
> for L2 cache controller
> soc: renesas: Add L2 cache management for RZ/Five SoC
>
> .../cache/andestech,ax45mp-cache.yaml | 93 ++++
> arch/riscv/Kconfig.erratas | 22 +
> arch/riscv/errata/Makefile | 1 +
> arch/riscv/errata/andes/Makefile | 1 +
> arch/riscv/errata/andes/errata.c | 139 ++++++
> arch/riscv/include/asm/alternative-macros.h | 94 ++++
> arch/riscv/include/asm/alternative.h | 3 +
> arch/riscv/include/asm/cacheflush.h | 12 +
> arch/riscv/include/asm/errata_list.h | 45 +-
> arch/riscv/include/asm/vendorid_list.h | 1 +
> arch/riscv/kernel/alternative.c | 5 +
> arch/riscv/mm/dma-noncoherent.c | 15 +-
> drivers/soc/renesas/Kconfig | 7 +
> drivers/soc/renesas/Makefile | 2 +
> drivers/soc/renesas/rzfive/Kconfig | 6 +
> drivers/soc/renesas/rzfive/Makefile | 3 +
> drivers/soc/renesas/rzfive/ax45mp_cache.c | 415 ++++++++++++++++++
> drivers/soc/renesas/rzfive/ax45mp_sbi.h | 29 ++
> .../cache/andestech,ax45mp-cache.h | 38 ++
> 19 files changed, 918 insertions(+), 13 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/cache/andestech,ax45mp-cache.yaml
> create mode 100644 arch/riscv/errata/andes/Makefile
> create mode 100644 arch/riscv/errata/andes/errata.c
> create mode 100644 drivers/soc/renesas/rzfive/Kconfig
> create mode 100644 drivers/soc/renesas/rzfive/Makefile
> create mode 100644 drivers/soc/renesas/rzfive/ax45mp_cache.c
> create mode 100644 drivers/soc/renesas/rzfive/ax45mp_sbi.h
> create mode 100644 include/dt-bindings/cache/andestech,ax45mp-cache.h
>
> --
> 2.25.1