arch/powerpc/platforms/powernv/vas.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2016-17 IBM Corp.
   4  */
   5
   6 #define pr_fmt(fmt) "vas: " fmt
   7
   8 #include <linux/module.h>
   9 #include <linux/kernel.h>
  10 #include <linux/export.h>
  11 #include <linux/types.h>
  12 #include <linux/slab.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/of_platform.h>
  15 #include <linux/of_address.h>
  16 #include <linux/of.h>
  17 #include <asm/prom.h>
  18
  19 #include "vas.h"
  20
  21 DEFINE_MUTEX(vas_mutex);
  22 static LIST_HEAD(vas_instances);
  23
  24 static DEFINE_PER_CPU(int, cpu_vas_id);
  25
  26 static int init_vas_instance(struct platform_device *pdev)
  27 {
  28         int rc, cpu, vasid;
  29         struct resource *res;
  30         struct vas_instance *vinst;
  31         struct device_node *dn = pdev->dev.of_node;
  32
  33         rc = of_property_read_u32(dn, "ibm,vas-id", &vasid);
  34         if (rc) {
  35                 pr_err("No ibm,vas-id property for %s?\n", pdev->name);
  36                 return -ENODEV;
  37         }
  38
  39         if (pdev->num_resources != 4) {
  40                 pr_err("Unexpected DT configuration for [%s, %d]\n",
  41                                 pdev->name, vasid);
  42                 return -ENODEV;
  43         }
  44
  45         vinst = kzalloc(sizeof(*vinst), GFP_KERNEL);
  46         if (!vinst)
  47                 return -ENOMEM;
  48
  49         INIT_LIST_HEAD(&vinst->node);
  50         ida_init(&vinst->ida);
  51         mutex_init(&vinst->mutex);
  52         vinst->vas_id = vasid;
  53         vinst->pdev = pdev;
  54
  55         res = &pdev->resource[0];
  56         vinst->hvwc_bar_start = res->start;
  57
  58         res = &pdev->resource[1];
  59         vinst->uwc_bar_start = res->start;
  60
  61         res = &pdev->resource[2];
  62         vinst->paste_base_addr = res->start;
  63
  64         res = &pdev->resource[3];
  65         if (res->end > 62) {
  66                 pr_err("Bad 'paste_win_id_shift' in DT, %llx\n", res->end);
  67                 goto free_vinst;
  68         }
  69
  70         vinst->paste_win_id_shift = 63 - res->end;
  71
  72         pr_devel("Initialized instance [%s, %d], paste_base 0x%llx, "
  73                         "paste_win_id_shift 0x%llx\n", pdev->name, vasid,
  74                         vinst->paste_base_addr, vinst->paste_win_id_shift);
  75
  76         for_each_possible_cpu(cpu) {
  77                 if (cpu_to_chip_id(cpu) == of_get_ibm_chip_id(dn))
  78                         per_cpu(cpu_vas_id, cpu) = vasid;
  79         }
  80
  81         mutex_lock(&vas_mutex);
  82         list_add(&vinst->node, &vas_instances);
  83         mutex_unlock(&vas_mutex);
  84
  85         vas_instance_init_dbgdir(vinst);
  86
  87         dev_set_drvdata(&pdev->dev, vinst);
  88
  89         return 0;
  90
  91 free_vinst:
  92         kfree(vinst);
  93         return -ENODEV;
  94
  95 }
  96
  97 /*
  98  * Although this is read/used multiple times, it is written to only
  99  * during initialization.
 100  */
 101 struct vas_instance *find_vas_instance(int vasid)
 102 {
 103         struct list_head *ent;
 104         struct vas_instance *vinst;
 105
 106         mutex_lock(&vas_mutex);
 107
 108         if (vasid == -1)
 109                 vasid = per_cpu(cpu_vas_id, smp_processor_id());
 110
 111         list_for_each(ent, &vas_instances) {
 112                 vinst = list_entry(ent, struct vas_instance, node);
 113                 if (vinst->vas_id == vasid) {
 114                         mutex_unlock(&vas_mutex);
 115                         return vinst;
 116                 }
 117         }
 118         mutex_unlock(&vas_mutex);
 119
 120         pr_devel("Instance %d not found\n", vasid);
 121         return NULL;
 122 }
 123
 124 int chip_to_vas_id(int chipid)
 125 {
 126         int cpu;
 127
 128         for_each_possible_cpu(cpu) {
 129                 if (cpu_to_chip_id(cpu) == chipid)
 130                         return per_cpu(cpu_vas_id, cpu);
 131         }
 132         return -1;
 133 }
 134 EXPORT_SYMBOL(chip_to_vas_id);
 135
 136 static int vas_probe(struct platform_device *pdev)
 137 {
 138         return init_vas_instance(pdev);
 139 }
 140
 141 static const struct of_device_id powernv_vas_match[] = {
 142         { .compatible = "ibm,vas",},
 143         {},
 144 };
 145
 146 static struct platform_driver vas_driver = {
 147         .driver = {
 148                 .name = "vas",
 149                 .of_match_table = powernv_vas_match,
 150         },
 151         .probe = vas_probe,
 152 };
 153
 154 static int __init vas_init(void)
 155 {
 156         int found = 0;
 157         struct device_node *dn;
 158
 159         platform_driver_register(&vas_driver);
 160
 161         for_each_compatible_node(dn, NULL, "ibm,vas") {
 162                 of_platform_device_create(dn, NULL, NULL);
 163                 found++;
 164         }
 165
 166         if (!found) {
 167                 platform_driver_unregister(&vas_driver);
 168                 return -ENODEV;
 169         }
 170
 171         pr_devel("Found %d instances\n", found);
 172
 173         return 0;
 174 }
 175 device_initcall(vas_init);