From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx> Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> Tested-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> # tyre-kicking on a d1 --- v11 -> v12 * No change v10 -> v11 * No change v9 -> v10 * Included TB tag from Conor v8 -> v9 * Rebased to code on Palmer's for/next * Dropped calling patch_text_nosync() as dont use patch_text_nosync() call v7 -> v8 * Now patching the code using patch_text_nosync() and riscv_alternative_fix_offsets() v6 -> v7 * Renamed RZFIVE_SBI_EXT_IOCP_SW_WORKAROUND -> ANDES_SBI_EXT_IOCP_SW_WORKAROUND * Dropped "depends on !XIP_KERNEL" for ERRATA_ANDES config 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.errata | 21 +++++++++ arch/riscv/errata/Makefile | 1 + arch/riscv/errata/andes/Makefile | 1 + arch/riscv/errata/andes/errata.c | 66 ++++++++++++++++++++++++++++ arch/riscv/include/asm/alternative.h | 3 ++ arch/riscv/include/asm/errata_list.h | 5 +++ arch/riscv/kernel/alternative.c | 5 +++ 7 files changed, 102 insertions(+) create mode 100644 arch/riscv/errata/andes/Makefile create mode 100644 arch/riscv/errata/andes/errata.c diff --git a/arch/riscv/Kconfig.errata b/arch/riscv/Kconfig.errata index 0c8f4652cd82..92c779764b27 100644 --- a/arch/riscv/Kconfig.errata +++ b/arch/riscv/Kconfig.errata @@ -1,5 +1,26 @@ menu "CPU errata selection" +config ERRATA_ANDES + bool "Andes AX45MP errata" + depends on 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 RISCV_ALTERNATIVE diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile index 7b2637c8c332..8a2739485123 100644 --- a/arch/riscv/errata/Makefile +++ b/arch/riscv/errata/Makefile @@ -2,5 +2,6 @@ ifdef CONFIG_RELOCATABLE KBUILD_CFLAGS += -fno-pie endif +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..197db68cc8da --- /dev/null +++ b/arch/riscv/errata/andes/errata.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Erratas to be applied for Andes CPU cores + * + * Copyright (C) 2023 Renesas Electronics Corporation. + * + * Author: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> + */ + +#include <linux/memory.h> +#include <linux/module.h> + +#include <asm/alternative.h> +#include <asm/cacheflush.h> +#include <asm/errata_list.h> +#include <asm/patch.h> +#include <asm/processor.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 ANDES_SBI_EXT_IOCP_SW_WORKAROUND 1 + +static long ax45mp_iocp_sw_workaround(void) +{ + struct sbiret ret; + + /* + * ANDES_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, ANDES_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; +} + +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) +{ + errata_probe_iocp(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 6a41537826a7..f6cfca939c92 100644 --- a/arch/riscv/include/asm/alternative.h +++ b/arch/riscv/include/asm/alternative.h @@ -46,6 +46,9 @@ struct alt_entry { u32 patch_id; /* The patch ID (erratum ID or cpufeature ID) */ }; +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/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h index fb1a810f3d8c..e2ecd01bfac7 100644 --- a/arch/riscv/include/asm/errata_list.h +++ b/arch/riscv/include/asm/errata_list.h @@ -11,6 +11,11 @@ #include <asm/hwcap.h> #include <asm/vendorid_list.h> +#ifdef CONFIG_ERRATA_ANDES +#define ERRATA_ANDESTECH_NO_IOCP 0 +#define ERRATA_ANDESTECH_NUMBER 1 +#endif + #ifdef CONFIG_ERRATA_SIFIVE #define ERRATA_SIFIVE_CIP_453 0 #define ERRATA_SIFIVE_CIP_1200 1 diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c index 6b75788c18e6..b0345992a35e 100644 --- a/arch/riscv/kernel/alternative.c +++ b/arch/riscv/kernel/alternative.c @@ -45,6 +45,11 @@ static void riscv_fill_cpu_mfr_info(struct cpu_manufacturer_info_t *cpu_mfr_info cpu_mfr_info->feature_probe_func = NULL; 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; -- 2.34.1