drivers/misc/cxl/vphb.c

   1 /*
   2  * Copyright 2014 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 #include <linux/pci.h>
  11 #include <misc/cxl.h>
  12 #include "cxl.h"
  13
  14 static int cxl_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
  15 {
  16         if (dma_mask < DMA_BIT_MASK(64)) {
  17                 pr_info("%s only 64bit DMA supported on CXL", __func__);
  18                 return -EIO;
  19         }
  20
  21         *(pdev->dev.dma_mask) = dma_mask;
  22         return 0;
  23 }
  24
  25 static int cxl_pci_probe_mode(struct pci_bus *bus)
  26 {
  27         return PCI_PROBE_NORMAL;
  28 }
  29
  30 static int cxl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
  31 {
  32         return -ENODEV;
  33 }
  34
  35 static void cxl_teardown_msi_irqs(struct pci_dev *pdev)
  36 {
  37         /*
  38          * MSI should never be set but need still need to provide this call
  39          * back.
  40          */
  41 }
  42
  43 static bool cxl_pci_enable_device_hook(struct pci_dev *dev)
  44 {
  45         struct pci_controller *phb;
  46         struct cxl_afu *afu;
  47         struct cxl_context *ctx;
  48
  49         phb = pci_bus_to_host(dev->bus);
  50         afu = (struct cxl_afu *)phb->private_data;
  51
  52         if (!cxl_ops->link_ok(afu->adapter, afu)) {
  53                 dev_warn(&dev->dev, "%s: Device link is down, refusing to enable AFU\n", __func__);
  54                 return false;
  55         }
  56
  57         set_dma_ops(&dev->dev, &dma_direct_ops);
  58         set_dma_offset(&dev->dev, PAGE_OFFSET);
  59
  60         /*
  61          * Allocate a context to do cxl things too.  If we eventually do real
  62          * DMA ops, we'll need a default context to attach them to
  63          */
  64         ctx = cxl_dev_context_init(dev);
  65         if (!ctx)
  66                 return false;
  67         dev->dev.archdata.cxl_ctx = ctx;
  68
  69         return (cxl_ops->afu_check_and_enable(afu) == 0);
  70 }
  71
  72 static void cxl_pci_disable_device(struct pci_dev *dev)
  73 {
  74         struct cxl_context *ctx = cxl_get_context(dev);
  75
  76         if (ctx) {
  77                 if (ctx->status == STARTED) {
  78                         dev_err(&dev->dev, "Default context started\n");
  79                         return;
  80                 }
  81                 dev->dev.archdata.cxl_ctx = NULL;
  82                 cxl_release_context(ctx);
  83         }
  84 }
  85
  86 static resource_size_t cxl_pci_window_alignment(struct pci_bus *bus,
  87                                                 unsigned long type)
  88 {
  89         return 1;
  90 }
  91
  92 static void cxl_pci_reset_secondary_bus(struct pci_dev *dev)
  93 {
  94         /* Should we do an AFU reset here ? */
  95 }
  96
  97 static int cxl_pcie_cfg_record(u8 bus, u8 devfn)
  98 {
  99         return (bus << 8) + devfn;
 100 }
 101
 102 static int cxl_pcie_config_info(struct pci_bus *bus, unsigned int devfn,
 103                                 struct cxl_afu **_afu, int *_record)
 104 {
 105         struct pci_controller *phb;
 106         struct cxl_afu *afu;
 107         int record;
 108
 109         phb = pci_bus_to_host(bus);
 110         if (phb == NULL)
 111                 return PCIBIOS_DEVICE_NOT_FOUND;
 112
 113         afu = (struct cxl_afu *)phb->private_data;
 114         record = cxl_pcie_cfg_record(bus->number, devfn);
 115         if (record > afu->crs_num)
 116                 return PCIBIOS_DEVICE_NOT_FOUND;
 117
 118         *_afu = afu;
 119         *_record = record;
 120         return 0;
 121 }
 122
 123 static int cxl_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
 124                                 int offset, int len, u32 *val)
 125 {
 126         int rc, record;
 127         struct cxl_afu *afu;
 128         u8 val8;
 129         u16 val16;
 130         u32 val32;
 131
 132         rc = cxl_pcie_config_info(bus, devfn, &afu, &record);
 133         if (rc)
 134                 return rc;
 135
 136         switch (len) {
 137         case 1:
 138                 rc = cxl_ops->afu_cr_read8(afu, record, offset, &val8);
 139                 *val = val8;
 140                 break;
 141         case 2:
 142                 rc = cxl_ops->afu_cr_read16(afu, record, offset, &val16);
 143                 *val = val16;
 144                 break;
 145         case 4:
 146                 rc = cxl_ops->afu_cr_read32(afu, record, offset, &val32);
 147                 *val = val32;
 148                 break;
 149         default:
 150                 WARN_ON(1);
 151         }
 152
 153         if (rc)
 154                 return PCIBIOS_DEVICE_NOT_FOUND;
 155
 156         return PCIBIOS_SUCCESSFUL;
 157 }
 158
 159 static int cxl_pcie_write_config(struct pci_bus *bus, unsigned int devfn,
 160                                  int offset, int len, u32 val)
 161 {
 162         int rc, record;
 163         struct cxl_afu *afu;
 164
 165         rc = cxl_pcie_config_info(bus, devfn, &afu, &record);
 166         if (rc)
 167                 return rc;
 168
 169         switch (len) {
 170         case 1:
 171                 rc = cxl_ops->afu_cr_write8(afu, record, offset, val & 0xff);
 172                 break;
 173         case 2:
 174                 rc = cxl_ops->afu_cr_write16(afu, record, offset, val & 0xffff);
 175                 break;
 176         case 4:
 177                 rc = cxl_ops->afu_cr_write32(afu, record, offset, val);
 178                 break;
 179         default:
 180                 WARN_ON(1);
 181         }
 182
 183         if (rc)
 184                 return PCIBIOS_SET_FAILED;
 185
 186         return PCIBIOS_SUCCESSFUL;
 187 }
 188
 189 static struct pci_ops cxl_pcie_pci_ops =
 190 {
 191         .read = cxl_pcie_read_config,
 192         .write = cxl_pcie_write_config,
 193 };
 194
 195
 196 static struct pci_controller_ops cxl_pci_controller_ops =
 197 {
 198         .probe_mode = cxl_pci_probe_mode,
 199         .enable_device_hook = cxl_pci_enable_device_hook,
 200         .disable_device = cxl_pci_disable_device,
 201         .release_device = cxl_pci_disable_device,
 202         .window_alignment = cxl_pci_window_alignment,
 203         .reset_secondary_bus = cxl_pci_reset_secondary_bus,
 204         .setup_msi_irqs = cxl_setup_msi_irqs,
 205         .teardown_msi_irqs = cxl_teardown_msi_irqs,
 206         .dma_set_mask = cxl_dma_set_mask,
 207 };
 208
 209 int cxl_pci_vphb_add(struct cxl_afu *afu)
 210 {
 211         struct pci_controller *phb;
 212         struct device_node *vphb_dn;
 213         struct device *parent;
 214
 215         /* The parent device is the adapter. Reuse the device node of
 216          * the adapter.
 217          * We don't seem to care what device node is used for the vPHB,
 218          * but tools such as lsvpd walk up the device parents looking
 219          * for a valid location code, so we might as well show devices
 220          * attached to the adapter as being located on that adapter.
 221          */
 222         parent = afu->adapter->dev.parent;
 223         vphb_dn = parent->of_node;
 224
 225         /* Alloc and setup PHB data structure */
 226         phb = pcibios_alloc_controller(vphb_dn);
 227         if (!phb)
 228                 return -ENODEV;
 229
 230         /* Setup parent in sysfs */
 231         phb->parent = parent;
 232
 233         /* Setup the PHB using arch provided callback */
 234         phb->ops = &cxl_pcie_pci_ops;
 235         phb->cfg_addr = NULL;
 236         phb->cfg_data = 0;
 237         phb->private_data = afu;
 238         phb->controller_ops = cxl_pci_controller_ops;
 239
 240         /* Scan the bus */
 241         pcibios_scan_phb(phb);
 242         if (phb->bus == NULL)
 243                 return -ENXIO;
 244
 245         /* Claim resources. This might need some rework as well depending
 246          * whether we are doing probe-only or not, like assigning unassigned
 247          * resources etc...
 248          */
 249         pcibios_claim_one_bus(phb->bus);
 250
 251         /* Add probed PCI devices to the device model */
 252         pci_bus_add_devices(phb->bus);
 253
 254         afu->phb = phb;
 255
 256         return 0;
 257 }
 258
 259 void cxl_pci_vphb_remove(struct cxl_afu *afu)
 260 {
 261         struct pci_controller *phb;
 262
 263         /* If there is no configuration record we won't have one of these */
 264         if (!afu || !afu->phb)
 265                 return;
 266
 267         phb = afu->phb;
 268         afu->phb = NULL;
 269
 270         pci_remove_root_bus(phb->bus);
 271         pcibios_free_controller(phb);
 272 }
 273
 274 bool cxl_pci_is_vphb_device(struct pci_dev *dev)
 275 {
 276         struct pci_controller *phb;
 277
 278         phb = pci_bus_to_host(dev->bus);
 279
 280         return (phb->ops == &cxl_pcie_pci_ops);
 281 }
 282
 283 struct cxl_afu *cxl_pci_to_afu(struct pci_dev *dev)
 284 {
 285         struct pci_controller *phb;
 286
 287         phb = pci_bus_to_host(dev->bus);
 288
 289         return (struct cxl_afu *)phb->private_data;
 290 }
 291 EXPORT_SYMBOL_GPL(cxl_pci_to_afu);
 292
 293 unsigned int cxl_pci_to_cfg_record(struct pci_dev *dev)
 294 {
 295         return cxl_pcie_cfg_record(dev->bus->number, dev->devfn);
 296 }
 297 EXPORT_SYMBOL_GPL(cxl_pci_to_cfg_record);