1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2022-2023, Ventana Micro Systems Inc
  4 *	Author: Sunil V L <sunilvl@ventanamicro.com>
  5 *
  6 */
  7
  8#define pr_fmt(fmt)     "ACPI: RHCT: " fmt
  9
 10#include <linux/acpi.h>
 11#include <linux/bits.h>
 12
 13static struct acpi_table_rhct *acpi_get_rhct(void)
 14{
 15	static struct acpi_table_header *rhct;
 16	acpi_status status;
 17
 18	/*
 19	 * RHCT will be used at runtime on every CPU, so we
 20	 * don't need to call acpi_put_table() to release the table mapping.
 21	 */
 22	if (!rhct) {
 23		status = acpi_get_table(ACPI_SIG_RHCT, 0, &rhct);
 24		if (ACPI_FAILURE(status)) {
 25			pr_warn_once("No RHCT table found\n");
 26			return NULL;
 27		}
 28	}
 29
 30	return (struct acpi_table_rhct *)rhct;
 31}
 32
 33/*
 34 * During early boot, the caller should call acpi_get_table() and pass its pointer to
 35 * these functions(and free up later). At run time, since this table can be used
 36 * multiple times, NULL may be passed in order to use the cached table.
 37 */
 38int acpi_get_riscv_isa(struct acpi_table_header *table, unsigned int cpu, const char **isa)
 39{
 40	struct acpi_rhct_node_header *node, *ref_node, *end;
 41	u32 size_hdr = sizeof(struct acpi_rhct_node_header);
 42	u32 size_hartinfo = sizeof(struct acpi_rhct_hart_info);
 43	struct acpi_rhct_hart_info *hart_info;
 44	struct acpi_rhct_isa_string *isa_node;
 45	struct acpi_table_rhct *rhct;
 46	u32 *hart_info_node_offset;
 47	u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
 48
 49	BUG_ON(acpi_disabled);
 50
 51	if (!table) {
 52		rhct = acpi_get_rhct();
 53		if (!rhct)
 54			return -ENOENT;
 55	} else {
 56		rhct = (struct acpi_table_rhct *)table;
 57	}
 58
 59	end = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->header.length);
 60
 61	for (node = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->node_offset);
 62	     node < end;
 63	     node = ACPI_ADD_PTR(struct acpi_rhct_node_header, node, node->length)) {
 64		if (node->type == ACPI_RHCT_NODE_TYPE_HART_INFO) {
 65			hart_info = ACPI_ADD_PTR(struct acpi_rhct_hart_info, node, size_hdr);
 66			hart_info_node_offset = ACPI_ADD_PTR(u32, hart_info, size_hartinfo);
 67			if (acpi_cpu_id != hart_info->uid)
 68				continue;
 69
 70			for (int i = 0; i < hart_info->num_offsets; i++) {
 71				ref_node = ACPI_ADD_PTR(struct acpi_rhct_node_header,
 72							rhct, hart_info_node_offset[i]);
 73				if (ref_node->type == ACPI_RHCT_NODE_TYPE_ISA_STRING) {
 74					isa_node = ACPI_ADD_PTR(struct acpi_rhct_isa_string,
 75								ref_node, size_hdr);
 76					*isa = isa_node->isa;
 77					return 0;
 78				}
 79			}
 80		}
 81	}
 82
 83	return -1;
 84}
 85
 86static void acpi_parse_hart_info_cmo_node(struct acpi_table_rhct *rhct,
 87					  struct acpi_rhct_hart_info *hart_info,
 88					  u32 *cbom_size, u32 *cboz_size, u32 *cbop_size)
 89{
 90	u32 size_hartinfo = sizeof(struct acpi_rhct_hart_info);
 91	u32 size_hdr = sizeof(struct acpi_rhct_node_header);
 92	struct acpi_rhct_node_header *ref_node;
 93	struct acpi_rhct_cmo_node *cmo_node;
 94	u32 *hart_info_node_offset;
 95
 96	hart_info_node_offset = ACPI_ADD_PTR(u32, hart_info, size_hartinfo);
 97	for (int i = 0; i < hart_info->num_offsets; i++) {
 98		ref_node = ACPI_ADD_PTR(struct acpi_rhct_node_header,
 99					rhct, hart_info_node_offset[i]);
100		if (ref_node->type == ACPI_RHCT_NODE_TYPE_CMO) {
101			cmo_node = ACPI_ADD_PTR(struct acpi_rhct_cmo_node,
102						ref_node, size_hdr);
103			if (cbom_size && cmo_node->cbom_size <= 30) {
104				if (!*cbom_size)
105					*cbom_size = BIT(cmo_node->cbom_size);
106				else if (*cbom_size != BIT(cmo_node->cbom_size))
107					pr_warn("CBOM size is not the same across harts\n");
108			}
109
110			if (cboz_size && cmo_node->cboz_size <= 30) {
111				if (!*cboz_size)
112					*cboz_size = BIT(cmo_node->cboz_size);
113				else if (*cboz_size != BIT(cmo_node->cboz_size))
114					pr_warn("CBOZ size is not the same across harts\n");
115			}
116
117			if (cbop_size && cmo_node->cbop_size <= 30) {
118				if (!*cbop_size)
119					*cbop_size = BIT(cmo_node->cbop_size);
120				else if (*cbop_size != BIT(cmo_node->cbop_size))
121					pr_warn("CBOP size is not the same across harts\n");
122			}
123		}
124	}
125}
126
127/*
128 * During early boot, the caller should call acpi_get_table() and pass its pointer to
129 * these functions (and free up later). At run time, since this table can be used
130 * multiple times, pass NULL so that the table remains in memory.
131 */
132void acpi_get_cbo_block_size(struct acpi_table_header *table, u32 *cbom_size,
133			     u32 *cboz_size, u32 *cbop_size)
134{
135	u32 size_hdr = sizeof(struct acpi_rhct_node_header);
136	struct acpi_rhct_node_header *node, *end;
137	struct acpi_rhct_hart_info *hart_info;
138	struct acpi_table_rhct *rhct;
139
140	if (acpi_disabled)
141		return;
142
143	if (table) {
144		rhct = (struct acpi_table_rhct *)table;
145	} else {
146		rhct = acpi_get_rhct();
147		if (!rhct)
148			return;
149	}
150
151	if (cbom_size)
152		*cbom_size = 0;
153
154	if (cboz_size)
155		*cboz_size = 0;
156
157	if (cbop_size)
158		*cbop_size = 0;
159
160	end = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->header.length);
161	for (node = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->node_offset);
162	     node < end;
163	     node = ACPI_ADD_PTR(struct acpi_rhct_node_header, node, node->length)) {
164		if (node->type == ACPI_RHCT_NODE_TYPE_HART_INFO) {
165			hart_info = ACPI_ADD_PTR(struct acpi_rhct_hart_info, node, size_hdr);
166			acpi_parse_hart_info_cmo_node(rhct, hart_info, cbom_size,
167						      cboz_size, cbop_size);
168		}
169	}
170}