RHCT is a new table defined for RISC-V to communicate the features of the CPU to the OS. Create a new architecture folder in drivers/acpi and add RHCT parsing code. Signed-off-by: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> --- arch/riscv/include/asm/acpi.h | 9 ++++ drivers/acpi/Makefile | 2 + drivers/acpi/riscv/Makefile | 2 + drivers/acpi/riscv/rhct.c | 92 +++++++++++++++++++++++++++++++++++ 4 files changed, 105 insertions(+) create mode 100644 drivers/acpi/riscv/Makefile create mode 100644 drivers/acpi/riscv/rhct.c diff --git a/arch/riscv/include/asm/acpi.h b/arch/riscv/include/asm/acpi.h index 4a3622b38159..7bc49f65c86b 100644 --- a/arch/riscv/include/asm/acpi.h +++ b/arch/riscv/include/asm/acpi.h @@ -58,6 +58,15 @@ static inline bool acpi_has_cpu_in_madt(void) static inline void arch_fix_phys_package_id(int num, u32 slot) { } +int acpi_get_riscv_isa(struct acpi_table_header *table, + unsigned int cpu, const char **isa); +#else +static inline int acpi_get_riscv_isa(struct acpi_table_header *table, + unsigned int cpu, const char **isa) +{ + return -EINVAL; +} + #endif /* CONFIG_ACPI */ #endif /*_ASM_ACPI_H*/ diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index feb36c0b9446..3fc5a0d54f6e 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -131,3 +131,5 @@ obj-y += dptf/ obj-$(CONFIG_ARM64) += arm64/ obj-$(CONFIG_ACPI_VIOT) += viot.o + +obj-$(CONFIG_RISCV) += riscv/ diff --git a/drivers/acpi/riscv/Makefile b/drivers/acpi/riscv/Makefile new file mode 100644 index 000000000000..8b3b126e0b94 --- /dev/null +++ b/drivers/acpi/riscv/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-y += rhct.o diff --git a/drivers/acpi/riscv/rhct.c b/drivers/acpi/riscv/rhct.c new file mode 100644 index 000000000000..5bafc236d627 --- /dev/null +++ b/drivers/acpi/riscv/rhct.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022-2023, Ventana Micro Systems Inc + * Author: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx> + * + */ + +#define pr_fmt(fmt) "ACPI: RHCT: " fmt + +#include <linux/acpi.h> + +static void acpi_rhct_warn_missing(void) +{ + pr_warn_once("No RHCT table found\n"); +} + +static struct acpi_table_header *acpi_get_rhct(void) +{ + static struct acpi_table_header *rhct; + acpi_status status; + + /* + * RHCT will be used at runtime on every CPU, so we + * don't need to call acpi_put_table() to release the table mapping. + */ + if (!rhct) { + status = acpi_get_table(ACPI_SIG_RHCT, 0, &rhct); + if (ACPI_FAILURE(status)) + acpi_rhct_warn_missing(); + } + + return rhct; +} + +/* + * During early boot, the caller should call acpi_get_table() and pass its pointer to + * these functions(and free up later). At run time, since this table can be used + * multiple times, pass NULL so that the table remains in memory + */ +int acpi_get_riscv_isa(struct acpi_table_header *table, unsigned int acpi_cpu_id, const char **isa) +{ + struct acpi_rhct_node_header *node, *ref_node, *end; + struct acpi_table_rhct *rhct; + struct acpi_rhct_hart_info *hart_info; + struct acpi_rhct_isa_string *isa_node; + u32 *hart_info_node_offset; + int i, j; + u32 size_hdr = sizeof(struct acpi_rhct_node_header); + u32 size_hartinfo = sizeof(struct acpi_rhct_hart_info); + + if (acpi_disabled) { + pr_debug("%s: acpi is disabled\n", __func__); + return -1; + } + + if (!table) { + rhct = (struct acpi_table_rhct *)acpi_get_rhct(); + if (!rhct) + return -ENOENT; + } else { + rhct = (struct acpi_table_rhct *)table; + } + + node = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->node_offset); + end = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->header.length); + + for (i = 0; i < rhct->node_count; i++) { + if (node >= end) + break; + switch (node->type) { + case ACPI_RHCT_NODE_TYPE_HART_INFO: + hart_info = ACPI_ADD_PTR(struct acpi_rhct_hart_info, node, size_hdr); + hart_info_node_offset = ACPI_ADD_PTR(u32, hart_info, size_hartinfo); + if (acpi_cpu_id != hart_info->uid) + break; + for (j = 0; j < hart_info->num_offsets; j++) { + ref_node = ACPI_ADD_PTR(struct acpi_rhct_node_header, + rhct, hart_info_node_offset[j]); + if (ref_node->type == ACPI_RHCT_NODE_TYPE_ISA_STRING) { + isa_node = ACPI_ADD_PTR(struct acpi_rhct_isa_string, + ref_node, size_hdr); + *isa = isa_node->isa; + return 0; + } + } + break; + } + node = ACPI_ADD_PTR(struct acpi_rhct_node_header, node, node->length); + } + + return -1; +} -- 2.34.1