drivers/acpi/riscv/rhct.c

   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
  13 static 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  */
  38 int 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
  86 static 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  */
 132 void 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 }