linux/arch/powerpc/platforms/powernv/vas.c
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   1/*
   2 * Copyright 2016-17 IBM Corp.
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of the GNU General Public License
   6 * as published by the Free Software Foundation; either version
   7 * 2 of the License, or (at your option) any later version.
   8 */
   9
  10#define pr_fmt(fmt) "vas: " fmt
  11
  12#include <linux/module.h>
  13#include <linux/kernel.h>
  14#include <linux/export.h>
  15#include <linux/types.h>
  16#include <linux/slab.h>
  17#include <linux/platform_device.h>
  18#include <linux/of_platform.h>
  19#include <linux/of_address.h>
  20#include <linux/of.h>
  21#include <asm/prom.h>
  22
  23#include "vas.h"
  24
  25DEFINE_MUTEX(vas_mutex);
  26static LIST_HEAD(vas_instances);
  27
  28static DEFINE_PER_CPU(int, cpu_vas_id);
  29
  30static int init_vas_instance(struct platform_device *pdev)
  31{
  32        int rc, cpu, vasid;
  33        struct resource *res;
  34        struct vas_instance *vinst;
  35        struct device_node *dn = pdev->dev.of_node;
  36
  37        rc = of_property_read_u32(dn, "ibm,vas-id", &vasid);
  38        if (rc) {
  39                pr_err("No ibm,vas-id property for %s?\n", pdev->name);
  40                return -ENODEV;
  41        }
  42
  43        if (pdev->num_resources != 4) {
  44                pr_err("Unexpected DT configuration for [%s, %d]\n",
  45                                pdev->name, vasid);
  46                return -ENODEV;
  47        }
  48
  49        vinst = kzalloc(sizeof(*vinst), GFP_KERNEL);
  50        if (!vinst)
  51                return -ENOMEM;
  52
  53        INIT_LIST_HEAD(&vinst->node);
  54        ida_init(&vinst->ida);
  55        mutex_init(&vinst->mutex);
  56        vinst->vas_id = vasid;
  57        vinst->pdev = pdev;
  58
  59        res = &pdev->resource[0];
  60        vinst->hvwc_bar_start = res->start;
  61
  62        res = &pdev->resource[1];
  63        vinst->uwc_bar_start = res->start;
  64
  65        res = &pdev->resource[2];
  66        vinst->paste_base_addr = res->start;
  67
  68        res = &pdev->resource[3];
  69        if (res->end > 62) {
  70                pr_err("Bad 'paste_win_id_shift' in DT, %llx\n", res->end);
  71                goto free_vinst;
  72        }
  73
  74        vinst->paste_win_id_shift = 63 - res->end;
  75
  76        pr_devel("Initialized instance [%s, %d], paste_base 0x%llx, "
  77                        "paste_win_id_shift 0x%llx\n", pdev->name, vasid,
  78                        vinst->paste_base_addr, vinst->paste_win_id_shift);
  79
  80        for_each_possible_cpu(cpu) {
  81                if (cpu_to_chip_id(cpu) == of_get_ibm_chip_id(dn))
  82                        per_cpu(cpu_vas_id, cpu) = vasid;
  83        }
  84
  85        mutex_lock(&vas_mutex);
  86        list_add(&vinst->node, &vas_instances);
  87        mutex_unlock(&vas_mutex);
  88
  89        vas_instance_init_dbgdir(vinst);
  90
  91        dev_set_drvdata(&pdev->dev, vinst);
  92
  93        return 0;
  94
  95free_vinst:
  96        kfree(vinst);
  97        return -ENODEV;
  98
  99}
 100
 101/*
 102 * Although this is read/used multiple times, it is written to only
 103 * during initialization.
 104 */
 105struct vas_instance *find_vas_instance(int vasid)
 106{
 107        struct list_head *ent;
 108        struct vas_instance *vinst;
 109
 110        mutex_lock(&vas_mutex);
 111
 112        if (vasid == -1)
 113                vasid = per_cpu(cpu_vas_id, smp_processor_id());
 114
 115        list_for_each(ent, &vas_instances) {
 116                vinst = list_entry(ent, struct vas_instance, node);
 117                if (vinst->vas_id == vasid) {
 118                        mutex_unlock(&vas_mutex);
 119                        return vinst;
 120                }
 121        }
 122        mutex_unlock(&vas_mutex);
 123
 124        pr_devel("Instance %d not found\n", vasid);
 125        return NULL;
 126}
 127
 128int chip_to_vas_id(int chipid)
 129{
 130        int cpu;
 131
 132        for_each_possible_cpu(cpu) {
 133                if (cpu_to_chip_id(cpu) == chipid)
 134                        return per_cpu(cpu_vas_id, cpu);
 135        }
 136        return -1;
 137}
 138EXPORT_SYMBOL(chip_to_vas_id);
 139
 140static int vas_probe(struct platform_device *pdev)
 141{
 142        return init_vas_instance(pdev);
 143}
 144
 145static const struct of_device_id powernv_vas_match[] = {
 146        { .compatible = "ibm,vas",},
 147        {},
 148};
 149
 150static struct platform_driver vas_driver = {
 151        .driver = {
 152                .name = "vas",
 153                .of_match_table = powernv_vas_match,
 154        },
 155        .probe = vas_probe,
 156};
 157
 158static int __init vas_init(void)
 159{
 160        int found = 0;
 161        struct device_node *dn;
 162
 163        platform_driver_register(&vas_driver);
 164
 165        for_each_compatible_node(dn, NULL, "ibm,vas") {
 166                of_platform_device_create(dn, NULL, NULL);
 167                found++;
 168        }
 169
 170        if (!found) {
 171                platform_driver_unregister(&vas_driver);
 172                return -ENODEV;
 173        }
 174
 175        pr_devel("Found %d instances\n", found);
 176
 177        return 0;
 178}
 179device_initcall(vas_init);
 180