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