diff options
Diffstat (limited to 'drivers/acpi/riscv/rhct.c')
| -rw-r--r-- | drivers/acpi/riscv/rhct.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/acpi/riscv/rhct.c b/drivers/acpi/riscv/rhct.c new file mode 100644 index 000000000000..caa2c16e1697 --- /dev/null +++ b/drivers/acpi/riscv/rhct.c @@ -0,0 +1,170 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022-2023, Ventana Micro Systems Inc + * Author: Sunil V L <sunilvl@ventanamicro.com> + * + */ + +#define pr_fmt(fmt) "ACPI: RHCT: " fmt + +#include <linux/acpi.h> +#include <linux/bits.h> + +static struct acpi_table_rhct *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)) { + pr_warn_once("No RHCT table found\n"); + return NULL; + } + } + + return (struct acpi_table_rhct *)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, NULL may be passed in order to use the cached table. + */ +int acpi_get_riscv_isa(struct acpi_table_header *table, unsigned int cpu, const char **isa) +{ + struct acpi_rhct_node_header *node, *ref_node, *end; + u32 size_hdr = sizeof(struct acpi_rhct_node_header); + u32 size_hartinfo = sizeof(struct acpi_rhct_hart_info); + struct acpi_rhct_hart_info *hart_info; + struct acpi_rhct_isa_string *isa_node; + struct acpi_table_rhct *rhct; + u32 *hart_info_node_offset; + u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); + + BUG_ON(acpi_disabled); + + if (!table) { + rhct = acpi_get_rhct(); + if (!rhct) + return -ENOENT; + } else { + rhct = (struct acpi_table_rhct *)table; + } + + end = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->header.length); + + for (node = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->node_offset); + node < end; + node = ACPI_ADD_PTR(struct acpi_rhct_node_header, node, node->length)) { + if (node->type == 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) + continue; + + for (int i = 0; i < hart_info->num_offsets; i++) { + ref_node = ACPI_ADD_PTR(struct acpi_rhct_node_header, + rhct, hart_info_node_offset[i]); + 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; + } + } + } + } + + return -1; +} + +static void acpi_parse_hart_info_cmo_node(struct acpi_table_rhct *rhct, + struct acpi_rhct_hart_info *hart_info, + u32 *cbom_size, u32 *cboz_size, u32 *cbop_size) +{ + u32 size_hartinfo = sizeof(struct acpi_rhct_hart_info); + u32 size_hdr = sizeof(struct acpi_rhct_node_header); + struct acpi_rhct_node_header *ref_node; + struct acpi_rhct_cmo_node *cmo_node; + u32 *hart_info_node_offset; + + hart_info_node_offset = ACPI_ADD_PTR(u32, hart_info, size_hartinfo); + for (int i = 0; i < hart_info->num_offsets; i++) { + ref_node = ACPI_ADD_PTR(struct acpi_rhct_node_header, + rhct, hart_info_node_offset[i]); + if (ref_node->type == ACPI_RHCT_NODE_TYPE_CMO) { + cmo_node = ACPI_ADD_PTR(struct acpi_rhct_cmo_node, + ref_node, size_hdr); + if (cbom_size && cmo_node->cbom_size <= 30) { + if (!*cbom_size) + *cbom_size = BIT(cmo_node->cbom_size); + else if (*cbom_size != BIT(cmo_node->cbom_size)) + pr_warn("CBOM size is not the same across harts\n"); + } + + if (cboz_size && cmo_node->cboz_size <= 30) { + if (!*cboz_size) + *cboz_size = BIT(cmo_node->cboz_size); + else if (*cboz_size != BIT(cmo_node->cboz_size)) + pr_warn("CBOZ size is not the same across harts\n"); + } + + if (cbop_size && cmo_node->cbop_size <= 30) { + if (!*cbop_size) + *cbop_size = BIT(cmo_node->cbop_size); + else if (*cbop_size != BIT(cmo_node->cbop_size)) + pr_warn("CBOP size is not the same across harts\n"); + } + } + } +} + +/* + * 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. + */ +void acpi_get_cbo_block_size(struct acpi_table_header *table, u32 *cbom_size, + u32 *cboz_size, u32 *cbop_size) +{ + u32 size_hdr = sizeof(struct acpi_rhct_node_header); + struct acpi_rhct_node_header *node, *end; + struct acpi_rhct_hart_info *hart_info; + struct acpi_table_rhct *rhct; + + if (acpi_disabled) + return; + + if (table) { + rhct = (struct acpi_table_rhct *)table; + } else { + rhct = acpi_get_rhct(); + if (!rhct) + return; + } + + if (cbom_size) + *cbom_size = 0; + + if (cboz_size) + *cboz_size = 0; + + if (cbop_size) + *cbop_size = 0; + + end = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->header.length); + for (node = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->node_offset); + node < end; + node = ACPI_ADD_PTR(struct acpi_rhct_node_header, node, node->length)) { + if (node->type == ACPI_RHCT_NODE_TYPE_HART_INFO) { + hart_info = ACPI_ADD_PTR(struct acpi_rhct_hart_info, node, size_hdr); + acpi_parse_hart_info_cmo_node(rhct, hart_info, cbom_size, + cboz_size, cbop_size); + } + } +} |