arch/x86/pci/sta2x11-fixup.c

   1 /*
   2  * arch/x86/pci/sta2x11-fixup.c
   3  * glue code for lib/swiotlb.c and DMA translation between STA2x11
   4  * AMBA memory mapping and the X86 memory mapping
   5  *
   6  * ST Microelectronics ConneXt (STA2X11/STA2X10)
   7  *
   8  * Copyright (c) 2010-2011 Wind River Systems, Inc.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  17  * See the GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  *
  23  */
  24
  25 #include <linux/pci.h>
  26 #include <linux/pci_ids.h>
  27 #include <linux/export.h>
  28 #include <linux/list.h>
  29
  30 #define STA2X11_SWIOTLB_SIZE (4*1024*1024)
  31 extern int swiotlb_late_init_with_default_size(size_t default_size);
  32
  33 /*
  34  * We build a list of bus numbers that are under the ConneXt. The
  35  * main bridge hosts 4 busses, which are the 4 endpoints, in order.
  36  */
  37 #define STA2X11_NR_EP           4       /* 0..3 included */
  38 #define STA2X11_NR_FUNCS        8       /* 0..7 included */
  39 #define STA2X11_AMBA_SIZE       (512 << 20)
  40
  41 struct sta2x11_ahb_regs { /* saved during suspend */
  42         u32 base, pexlbase, pexhbase, crw;
  43 };
  44
  45 struct sta2x11_mapping {
  46         u32 amba_base;
  47         int is_suspended;
  48         struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS];
  49 };
  50
  51 struct sta2x11_instance {
  52         struct list_head list;
  53         int bus0;
  54         struct sta2x11_mapping map[STA2X11_NR_EP];
  55 };
  56
  57 static LIST_HEAD(sta2x11_instance_list);
  58
  59 /* At probe time, record new instances of this bridge (likely one only) */
  60 static void sta2x11_new_instance(struct pci_dev *pdev)
  61 {
  62         struct sta2x11_instance *instance;
  63
  64         instance = kzalloc(sizeof(*instance), GFP_ATOMIC);
  65         if (!instance)
  66                 return;
  67         /* This has a subordinate bridge, with 4 more-subordinate ones */
  68         instance->bus0 = pdev->subordinate->number + 1;
  69
  70         if (list_empty(&sta2x11_instance_list)) {
  71                 int size = STA2X11_SWIOTLB_SIZE;
  72                 /* First instance: register your own swiotlb area */
  73                 dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size);
  74                 if (swiotlb_late_init_with_default_size(size))
  75                         dev_emerg(&pdev->dev, "init swiotlb failed\n");
  76         }
  77         list_add(&instance->list, &sta2x11_instance_list);
  78 }
  79 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance);
  80
  81 /*
  82  * Utility functions used in this file from below
  83  */
  84 static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev)
  85 {
  86         struct sta2x11_instance *instance;
  87         int ep;
  88
  89         list_for_each_entry(instance, &sta2x11_instance_list, list) {
  90                 ep = pdev->bus->number - instance->bus0;
  91                 if (ep >= 0 && ep < STA2X11_NR_EP)
  92                         return instance;
  93         }
  94         return NULL;
  95 }
  96
  97 static int sta2x11_pdev_to_ep(struct pci_dev *pdev)
  98 {
  99         struct sta2x11_instance *instance;
 100
 101         instance = sta2x11_pdev_to_instance(pdev);
 102         if (!instance)
 103                 return -1;
 104
 105         return pdev->bus->number - instance->bus0;
 106 }
 107
 108 static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev)
 109 {
 110         struct sta2x11_instance *instance;
 111         int ep;
 112
 113         instance = sta2x11_pdev_to_instance(pdev);
 114         if (!instance)
 115                 return NULL;
 116         ep = sta2x11_pdev_to_ep(pdev);
 117         return instance->map + ep;
 118 }
 119
 120 /* This is exported, as some devices need to access the MFD registers */
 121 struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev)
 122 {
 123         return sta2x11_pdev_to_instance(pdev);
 124 }
 125 EXPORT_SYMBOL(sta2x11_get_instance);
 126
 127
 128 /**
 129  * p2a - Translate physical address to STA2x11 AMBA address,
 130  *       used for DMA transfers to STA2x11
 131  * @p: Physical address
 132  * @pdev: PCI device (must be hosted within the connext)
 133  */
 134 static dma_addr_t p2a(dma_addr_t p, struct pci_dev *pdev)
 135 {
 136         struct sta2x11_mapping *map;
 137         dma_addr_t a;
 138
 139         map = sta2x11_pdev_to_mapping(pdev);
 140         a = p + map->amba_base;
 141         return a;
 142 }
 143
 144 /**
 145  * a2p - Translate STA2x11 AMBA address to physical address
 146  *       used for DMA transfers from STA2x11
 147  * @a: STA2x11 AMBA address
 148  * @pdev: PCI device (must be hosted within the connext)
 149  */
 150 static dma_addr_t a2p(dma_addr_t a, struct pci_dev *pdev)
 151 {
 152         struct sta2x11_mapping *map;
 153         dma_addr_t p;
 154
 155         map = sta2x11_pdev_to_mapping(pdev);
 156         p = a - map->amba_base;
 157         return p;
 158 }
 159
 160 /**
 161  * sta2x11_swiotlb_alloc_coherent - Allocate swiotlb bounce buffers
 162  *     returns virtual address. This is the only "special" function here.
 163  * @dev: PCI device
 164  * @size: Size of the buffer
 165  * @dma_handle: DMA address
 166  * @flags: memory flags
 167  */
 168 static void *sta2x11_swiotlb_alloc_coherent(struct device *dev,
 169                                             size_t size,
 170                                             dma_addr_t *dma_handle,
 171                                             gfp_t flags,
 172                                             unsigned long attrs)
 173 {
 174         void *vaddr;
 175
 176         vaddr = x86_swiotlb_alloc_coherent(dev, size, dma_handle, flags, attrs);
 177         *dma_handle = p2a(*dma_handle, to_pci_dev(dev));
 178         return vaddr;
 179 }
 180
 181 /* We have our own dma_ops: the same as swiotlb but from alloc (above) */
 182 static const struct dma_map_ops sta2x11_dma_ops = {
 183         .alloc = sta2x11_swiotlb_alloc_coherent,
 184         .free = x86_swiotlb_free_coherent,
 185         .map_page = swiotlb_map_page,
 186         .unmap_page = swiotlb_unmap_page,
 187         .map_sg = swiotlb_map_sg_attrs,
 188         .unmap_sg = swiotlb_unmap_sg_attrs,
 189         .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
 190         .sync_single_for_device = swiotlb_sync_single_for_device,
 191         .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
 192         .sync_sg_for_device = swiotlb_sync_sg_for_device,
 193         .mapping_error = swiotlb_dma_mapping_error,
 194         .dma_supported = NULL, /* FIXME: we should use this instead! */
 195 };
 196
 197 /* At setup time, we use our own ops if the device is a ConneXt one */
 198 static void sta2x11_setup_pdev(struct pci_dev *pdev)
 199 {
 200         struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);
 201
 202         if (!instance) /* either a sta2x11 bridge or another ST device */
 203                 return;
 204         pci_set_consistent_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
 205         pci_set_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
 206         pdev->dev.dma_ops = &sta2x11_dma_ops;
 207
 208         /* We must enable all devices as master, for audio DMA to work */
 209         pci_set_master(pdev);
 210 }
 211 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev);
 212
 213 /*
 214  * The following three functions are exported (used in swiotlb: FIXME)
 215  */
 216 /**
 217  * dma_capable - Check if device can manage DMA transfers (FIXME: kill it)
 218  * @dev: device for a PCI device
 219  * @addr: DMA address
 220  * @size: DMA size
 221  */
 222 bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
 223 {
 224         struct sta2x11_mapping *map;
 225
 226         if (dev->dma_ops != &sta2x11_dma_ops) {
 227                 if (!dev->dma_mask)
 228                         return false;
 229                 return addr + size - 1 <= *dev->dma_mask;
 230         }
 231
 232         map = sta2x11_pdev_to_mapping(to_pci_dev(dev));
 233
 234         if (!map || (addr < map->amba_base))
 235                 return false;
 236         if (addr + size >= map->amba_base + STA2X11_AMBA_SIZE) {
 237                 return false;
 238         }
 239
 240         return true;
 241 }
 242
 243 /**
 244  * phys_to_dma - Return the DMA AMBA address used for this STA2x11 device
 245  * @dev: device for a PCI device
 246  * @paddr: Physical address
 247  */
 248 dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
 249 {
 250         if (dev->dma_ops != &sta2x11_dma_ops)
 251                 return paddr;
 252         return p2a(paddr, to_pci_dev(dev));
 253 }
 254
 255 /**
 256  * dma_to_phys - Return the physical address used for this STA2x11 DMA address
 257  * @dev: device for a PCI device
 258  * @daddr: STA2x11 AMBA DMA address
 259  */
 260 phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
 261 {
 262         if (dev->dma_ops != &sta2x11_dma_ops)
 263                 return daddr;
 264         return a2p(daddr, to_pci_dev(dev));
 265 }
 266
 267
 268 /*
 269  * At boot we must set up the mappings for the pcie-to-amba bridge.
 270  * It involves device access, and the same happens at suspend/resume time
 271  */
 272
 273 #define AHB_MAPB                0xCA4
 274 #define AHB_CRW(i)              (AHB_MAPB + 0  + (i) * 0x10)
 275 #define AHB_CRW_SZMASK                  0xfffffc00UL
 276 #define AHB_CRW_ENABLE                  (1 << 0)
 277 #define AHB_CRW_WTYPE_MEM               (2 << 1)
 278 #define AHB_CRW_ROE                     (1UL << 3)      /* Relax Order Ena */
 279 #define AHB_CRW_NSE                     (1UL << 4)      /* No Snoop Enable */
 280 #define AHB_BASE(i)             (AHB_MAPB + 4  + (i) * 0x10)
 281 #define AHB_PEXLBASE(i)         (AHB_MAPB + 8  + (i) * 0x10)
 282 #define AHB_PEXHBASE(i)         (AHB_MAPB + 12 + (i) * 0x10)
 283
 284 /* At probe time, enable mapping for each endpoint, using the pdev */
 285 static void sta2x11_map_ep(struct pci_dev *pdev)
 286 {
 287         struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
 288         int i;
 289
 290         if (!map)
 291                 return;
 292         pci_read_config_dword(pdev, AHB_BASE(0), &map->amba_base);
 293
 294         /* Configure AHB mapping */
 295         pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0);
 296         pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0);
 297         pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE |
 298                                AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE);
 299
 300         /* Disable all the other windows */
 301         for (i = 1; i < STA2X11_NR_FUNCS; i++)
 302                 pci_write_config_dword(pdev, AHB_CRW(i), 0);
 303
 304         dev_info(&pdev->dev,
 305                  "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n",
 306                  sta2x11_pdev_to_ep(pdev),  map->amba_base,
 307                  map->amba_base + STA2X11_AMBA_SIZE - 1);
 308 }
 309 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep);
 310
 311 #ifdef CONFIG_PM /* Some register values must be saved and restored */
 312
 313 static void suspend_mapping(struct pci_dev *pdev)
 314 {
 315         struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
 316         int i;
 317
 318         if (!map)
 319                 return;
 320
 321         if (map->is_suspended)
 322                 return;
 323         map->is_suspended = 1;
 324
 325         /* Save all window configs */
 326         for (i = 0; i < STA2X11_NR_FUNCS; i++) {
 327                 struct sta2x11_ahb_regs *regs = map->regs + i;
 328
 329                 pci_read_config_dword(pdev, AHB_BASE(i), &regs->base);
 330                 pci_read_config_dword(pdev, AHB_PEXLBASE(i), &regs->pexlbase);
 331                 pci_read_config_dword(pdev, AHB_PEXHBASE(i), &regs->pexhbase);
 332                 pci_read_config_dword(pdev, AHB_CRW(i), &regs->crw);
 333         }
 334 }
 335 DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping);
 336
 337 static void resume_mapping(struct pci_dev *pdev)
 338 {
 339         struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
 340         int i;
 341
 342         if (!map)
 343                 return;
 344
 345
 346         if (!map->is_suspended)
 347                 goto out;
 348         map->is_suspended = 0;
 349
 350         /* Restore all window configs */
 351         for (i = 0; i < STA2X11_NR_FUNCS; i++) {
 352                 struct sta2x11_ahb_regs *regs = map->regs + i;
 353
 354                 pci_write_config_dword(pdev, AHB_BASE(i), regs->base);
 355                 pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase);
 356                 pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase);
 357                 pci_write_config_dword(pdev, AHB_CRW(i), regs->crw);
 358         }
 359 out:
 360         pci_set_master(pdev); /* Like at boot, enable master on all devices */
 361 }
 362 DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping);
 363
 364 #endif /* CONFIG_PM */