| Message ID | 20230106185526.260163-4-prabhakar.mahadev-lad.rj@bp.renesas.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Palmer Dabbelt |
| Headers | show |
| Series | RISC-V non-coherent function pointer based cache management operations + non-coherent DMA support for AX45MP | expand |
On Fri, Jan 06, 2023 at 06:55:23PM +0000, Prabhakar wrote: > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> > > Add required ports of the Alternative scheme for Andes CPU cores. > > I/O Coherence Port (IOCP) provides an AXI interface for connecting external > non-caching masters, such as DMA controllers. IOCP is a specification > option and is disabled on the Renesas RZ/Five SoC due to this reason cache > management needs a software workaround. > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> > --- > v5 -> v6 > * Dropped patching alternative and now just probing IOCP > > v4 -> v5 > * Sorted the Kconfig/Makefile/Switch based on Core name > * Added a comments > * Introduced RZFIVE_SBI_EXT_IOCP_SW_WORKAROUND SBI EXT ID to check if > CMO needs to be applied. Is there a way we can access the DTB while patching > as we can drop this SBI EXT ID and add a DT property instead for cmo? > > RFC v3 -> v4 > * New patch > --- > arch/riscv/Kconfig.erratas | 22 +++++++++ > arch/riscv/errata/Makefile | 1 + > arch/riscv/errata/andes/Makefile | 1 + > arch/riscv/errata/andes/errata.c | 71 ++++++++++++++++++++++++++++ > arch/riscv/include/asm/alternative.h | 3 ++ > arch/riscv/kernel/alternative.c | 5 ++ > 6 files changed, 103 insertions(+) > create mode 100644 arch/riscv/errata/andes/Makefile > create mode 100644 arch/riscv/errata/andes/errata.c > > diff --git a/arch/riscv/Kconfig.erratas b/arch/riscv/Kconfig.erratas > index 69621ae6d647..f0f0c1abd52b 100644 > --- a/arch/riscv/Kconfig.erratas > +++ b/arch/riscv/Kconfig.erratas > @@ -1,5 +1,27 @@ > menu "CPU errata selection" > > +config ERRATA_ANDES > + bool "Andes AX45MP errata" > + depends on !XIP_KERNEL > + select RISCV_ALTERNATIVE > + help > + All Andes errata Kconfig depend on this Kconfig. Disabling > + this Kconfig will disable all Andes errata. Please say "Y" > + here if your platform uses Andes CPU cores. > + > + Otherwise, please say "N" here to avoid unnecessary overhead. > + > +config ERRATA_ANDES_CMO > + bool "Apply Andes cache management errata" > + depends on ERRATA_ANDES && MMU && ARCH_R9A07G043 > + select RISCV_DMA_NONCOHERENT > + default y > + help > + This will apply the cache management errata to handle the > + non-standard handling on non-coherent operations on Andes cores. > + > + If you don't know what to do here, say "Y". Ideally we would not need errata to turn this stuff on at all, but, as you pointed out to me off-list, arch_setup_dma_ops() complains if we have not set up. I'm happy to commit to trying to sort that out in follow on work w/ MPFS, since in that case it really isn't errata, and not require it for this series as you do fit that particular bill IMO. Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Thanks, Conor.
diff --git a/arch/riscv/Kconfig.erratas b/arch/riscv/Kconfig.erratas index 69621ae6d647..f0f0c1abd52b 100644 --- a/arch/riscv/Kconfig.erratas +++ b/arch/riscv/Kconfig.erratas @@ -1,5 +1,27 @@ menu "CPU errata selection" +config ERRATA_ANDES + bool "Andes AX45MP errata" + depends on !XIP_KERNEL + select RISCV_ALTERNATIVE + help + All Andes errata Kconfig depend on this Kconfig. Disabling + this Kconfig will disable all Andes errata. Please say "Y" + here if your platform uses Andes CPU cores. + + Otherwise, please say "N" here to avoid unnecessary overhead. + +config ERRATA_ANDES_CMO + bool "Apply Andes cache management errata" + depends on ERRATA_ANDES && MMU && ARCH_R9A07G043 + select RISCV_DMA_NONCOHERENT + default y + help + This will apply the cache management errata to handle the + non-standard handling on non-coherent operations on Andes cores. + + If you don't know what to do here, say "Y". + config ERRATA_SIFIVE bool "SiFive errata" depends on !XIP_KERNEL diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile index a1055965fbee..6f1c693af92d 100644 --- a/arch/riscv/errata/Makefile +++ b/arch/riscv/errata/Makefile @@ -1,2 +1,3 @@ +obj-$(CONFIG_ERRATA_ANDES) += andes/ obj-$(CONFIG_ERRATA_SIFIVE) += sifive/ obj-$(CONFIG_ERRATA_THEAD) += thead/ diff --git a/arch/riscv/errata/andes/Makefile b/arch/riscv/errata/andes/Makefile new file mode 100644 index 000000000000..2d644e19caef --- /dev/null +++ b/arch/riscv/errata/andes/Makefile @@ -0,0 +1 @@ +obj-y += errata.o diff --git a/arch/riscv/errata/andes/errata.c b/arch/riscv/errata/andes/errata.c new file mode 100644 index 000000000000..d893c0aabd23 --- /dev/null +++ b/arch/riscv/errata/andes/errata.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Erratas to be applied for Andes CPU cores + * + * Copyright (C) 2022 Renesas Electronics Corporation. + * + * Author: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> + */ + +#include <asm/cacheflush.h> +#include <asm/dma-noncoherent.h> +#include <asm/errata_list.h> +#include <asm/patch.h> +#include <asm/sbi.h> +#include <asm/vendorid_list.h> + +#define ANDESTECH_AX45MP_MARCHID 0x8000000000008a45UL +#define ANDESTECH_AX45MP_MIMPID 0x500UL +#define ANDESTECH_SBI_EXT_ANDES 0x0900031E + +#define RZFIVE_SBI_EXT_IOCP_SW_WORKAROUND 0 + +static long ax45mp_iocp_sw_workaround(void) +{ + struct sbiret ret; + + /* + * RZFIVE_SBI_EXT_IOCP_SW_WORKAROUND SBI EXT checks if the IOCP is missing and + * cache is controllable only then CMO will be applied to the platform. + */ + ret = sbi_ecall(ANDESTECH_SBI_EXT_ANDES, RZFIVE_SBI_EXT_IOCP_SW_WORKAROUND, + 0, 0, 0, 0, 0, 0); + + return ret.error ? 0 : ret.value; +} + +static bool errata_probe_iocp(unsigned int stage, unsigned long arch_id, unsigned long impid) +{ + if (!IS_ENABLED(CONFIG_ERRATA_ANDES_CMO)) + return false; + + if (arch_id != ANDESTECH_AX45MP_MARCHID || impid != ANDESTECH_AX45MP_MIMPID) + return false; + + if (!ax45mp_iocp_sw_workaround()) + return false; + + /* Set this just to make core cbo code happy */ + riscv_cbom_block_size = 1; + riscv_noncoherent_supported(); + + return true; +} + +static void andes_errata_probe(unsigned int stage, unsigned long archid, unsigned long impid) +{ + /* + * In the absence of the I/O Coherency Port, access to certain peripherals + * requires vendor specific DMA handling. + */ + errata_probe_iocp(stage, archid, impid); +} + +void __init_or_module andes_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, + unsigned long archid, unsigned long impid, + unsigned int stage) +{ + andes_errata_probe(stage, archid, impid); + + /* we have nothing to patch here ATM so just return back */ +} diff --git a/arch/riscv/include/asm/alternative.h b/arch/riscv/include/asm/alternative.h index 1bd4027d34ca..e3a8e603eb5a 100644 --- a/arch/riscv/include/asm/alternative.h +++ b/arch/riscv/include/asm/alternative.h @@ -43,6 +43,9 @@ struct errata_checkfunc_id { bool (*func)(struct alt_entry *alt); }; +void andes_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, + unsigned long archid, unsigned long impid, + unsigned int stage); void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, unsigned long archid, unsigned long impid, unsigned int stage); diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c index 6212ea0eed72..d7027a977ee6 100644 --- a/arch/riscv/kernel/alternative.c +++ b/arch/riscv/kernel/alternative.c @@ -40,6 +40,11 @@ static void __init_or_module riscv_fill_cpu_mfr_info(struct cpu_manufacturer_inf #endif switch (cpu_mfr_info->vendor_id) { +#ifdef CONFIG_ERRATA_ANDES + case ANDESTECH_VENDOR_ID: + cpu_mfr_info->patch_func = andes_errata_patch_func; + break; +#endif #ifdef CONFIG_ERRATA_SIFIVE case SIFIVE_VENDOR_ID: cpu_mfr_info->patch_func = sifive_errata_patch_func;