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 <linux/irqdomain.h>
  18 #include <linux/interrupt.h>
  19 #include <asm/prom.h>
  20 #include <asm/xive.h>
  21
  22 #include "vas.h"
  23
  24 DEFINE_MUTEX(vas_mutex);
  25 static LIST_HEAD(vas_instances);
  26
  27 static DEFINE_PER_CPU(int, cpu_vas_id);
  28
  29 static int vas_irq_fault_window_setup(struct vas_instance *vinst)
  30 {
  31         char devname[64];
  32         int rc = 0;
  33
  34         snprintf(devname, sizeof(devname), "vas-%d", vinst->vas_id);
  35         rc = request_threaded_irq(vinst->virq, vas_fault_handler,
  36                                 vas_fault_thread_fn, 0, devname, vinst);
  37
  38         if (rc) {
  39                 pr_err("VAS[%d]: Request IRQ(%d) failed with %d\n",
  40                                 vinst->vas_id, vinst->virq, rc);
  41                 goto out;
  42         }
  43
  44         rc = vas_setup_fault_window(vinst);
  45         if (rc)
  46                 free_irq(vinst->virq, vinst);
  47
  48 out:
  49         return rc;
  50 }
  51
  52 static int init_vas_instance(struct platform_device *pdev)
  53 {
  54         struct device_node *dn = pdev->dev.of_node;
  55         struct vas_instance *vinst;
  56         struct xive_irq_data *xd;
  57         uint32_t chipid, hwirq;
  58         struct resource *res;
  59         int rc, cpu, vasid;
  60
  61         rc = of_property_read_u32(dn, "ibm,vas-id", &vasid);
  62         if (rc) {
  63                 pr_err("No ibm,vas-id property for %s?\n", pdev->name);
  64                 return -ENODEV;
  65         }
  66
  67         rc = of_property_read_u32(dn, "ibm,chip-id", &chipid);
  68         if (rc) {
  69                 pr_err("No ibm,chip-id property for %s?\n", pdev->name);
  70                 return -ENODEV;
  71         }
  72
  73         if (pdev->num_resources != 4) {
  74                 pr_err("Unexpected DT configuration for [%s, %d]\n",
  75                                 pdev->name, vasid);
  76                 return -ENODEV;
  77         }
  78
  79         vinst = kzalloc(sizeof(*vinst), GFP_KERNEL);
  80         if (!vinst)
  81                 return -ENOMEM;
  82
  83         INIT_LIST_HEAD(&vinst->node);
  84         ida_init(&vinst->ida);
  85         mutex_init(&vinst->mutex);
  86         vinst->vas_id = vasid;
  87         vinst->pdev = pdev;
  88
  89         res = &pdev->resource[0];
  90         vinst->hvwc_bar_start = res->start;
  91
  92         res = &pdev->resource[1];
  93         vinst->uwc_bar_start = res->start;
  94
  95         res = &pdev->resource[2];
  96         vinst->paste_base_addr = res->start;
  97
  98         res = &pdev->resource[3];
  99         if (res->end > 62) {
 100                 pr_err("Bad 'paste_win_id_shift' in DT, %llx\n", res->end);
 101                 goto free_vinst;
 102         }
 103
 104         vinst->paste_win_id_shift = 63 - res->end;
 105
 106         hwirq = xive_native_alloc_irq_on_chip(chipid);
 107         if (!hwirq) {
 108                 pr_err("Inst%d: Unable to allocate global irq for chip %d\n",
 109                                 vinst->vas_id, chipid);
 110                 return -ENOENT;
 111         }
 112
 113         vinst->virq = irq_create_mapping(NULL, hwirq);
 114         if (!vinst->virq) {
 115                 pr_err("Inst%d: Unable to map global irq %d\n",
 116                                 vinst->vas_id, hwirq);
 117                 return -EINVAL;
 118         }
 119
 120         xd = irq_get_handler_data(vinst->virq);
 121         if (!xd) {
 122                 pr_err("Inst%d: Invalid virq %d\n",
 123                                 vinst->vas_id, vinst->virq);
 124                 return -EINVAL;
 125         }
 126
 127         vinst->irq_port = xd->trig_page;
 128         pr_devel("Initialized instance [%s, %d] paste_base 0x%llx paste_win_id_shift 0x%llx IRQ %d Port 0x%llx\n",
 129                         pdev->name, vasid, vinst->paste_base_addr,
 130                         vinst->paste_win_id_shift, vinst->virq,
 131                         vinst->irq_port);
 132
 133         for_each_possible_cpu(cpu) {
 134                 if (cpu_to_chip_id(cpu) == of_get_ibm_chip_id(dn))
 135                         per_cpu(cpu_vas_id, cpu) = vasid;
 136         }
 137
 138         mutex_lock(&vas_mutex);
 139         list_add(&vinst->node, &vas_instances);
 140         mutex_unlock(&vas_mutex);
 141
 142         spin_lock_init(&vinst->fault_lock);
 143         /*
 144          * IRQ and fault handling setup is needed only for user space
 145          * send windows.
 146          */
 147         if (vinst->virq) {
 148                 rc = vas_irq_fault_window_setup(vinst);
 149                 /*
 150                  * Fault window is used only for user space send windows.
 151                  * So if vinst->virq is NULL, tx_win_open returns -ENODEV
 152                  * for user space.
 153                  */
 154                 if (rc)
 155                         vinst->virq = 0;
 156         }
 157
 158         vas_instance_init_dbgdir(vinst);
 159
 160         dev_set_drvdata(&pdev->dev, vinst);
 161
 162         return 0;
 163
 164 free_vinst:
 165         kfree(vinst);
 166         return -ENODEV;
 167
 168 }
 169
 170 /*
 171  * Although this is read/used multiple times, it is written to only
 172  * during initialization.
 173  */
 174 struct vas_instance *find_vas_instance(int vasid)
 175 {
 176         struct list_head *ent;
 177         struct vas_instance *vinst;
 178
 179         mutex_lock(&vas_mutex);
 180
 181         if (vasid == -1)
 182                 vasid = per_cpu(cpu_vas_id, smp_processor_id());
 183
 184         list_for_each(ent, &vas_instances) {
 185                 vinst = list_entry(ent, struct vas_instance, node);
 186                 if (vinst->vas_id == vasid) {
 187                         mutex_unlock(&vas_mutex);
 188                         return vinst;
 189                 }
 190         }
 191         mutex_unlock(&vas_mutex);
 192
 193         pr_devel("Instance %d not found\n", vasid);
 194         return NULL;
 195 }
 196
 197 int chip_to_vas_id(int chipid)
 198 {
 199         int cpu;
 200
 201         for_each_possible_cpu(cpu) {
 202                 if (cpu_to_chip_id(cpu) == chipid)
 203                         return per_cpu(cpu_vas_id, cpu);
 204         }
 205         return -1;
 206 }
 207 EXPORT_SYMBOL(chip_to_vas_id);
 208
 209 static int vas_probe(struct platform_device *pdev)
 210 {
 211         return init_vas_instance(pdev);
 212 }
 213
 214 static const struct of_device_id powernv_vas_match[] = {
 215         { .compatible = "ibm,vas",},
 216         {},
 217 };
 218
 219 static struct platform_driver vas_driver = {
 220         .driver = {
 221                 .name = "vas",
 222                 .of_match_table = powernv_vas_match,
 223         },
 224         .probe = vas_probe,
 225 };
 226
 227 static int __init vas_init(void)
 228 {
 229         int found = 0;
 230         struct device_node *dn;
 231
 232         platform_driver_register(&vas_driver);
 233
 234         for_each_compatible_node(dn, NULL, "ibm,vas") {
 235                 of_platform_device_create(dn, NULL, NULL);
 236                 found++;
 237         }
 238
 239         if (!found) {
 240                 platform_driver_unregister(&vas_driver);
 241                 return -ENODEV;
 242         }
 243
 244         pr_devel("Found %d instances\n", found);
 245
 246         return 0;
 247 }
 248 device_initcall(vas_init);