drivers/acpi/riscv/rhct.c

Source file repositories/reference/linux-study-clean/drivers/acpi/riscv/rhct.c

File Facts

System
Linux kernel
Corpus path
drivers/acpi/riscv/rhct.c
Extension
.c
Size
5204 bytes
Lines
176
Domain
Driver Families
Bucket
drivers/acpi
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

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;
	int ret;

	BUG_ON(acpi_disabled);

	ret = acpi_get_cpu_uid(cpu, &acpi_cpu_id);
	if (ret != 0)
		return ret;

	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");
			}

Annotation

Implementation Notes