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 #include <linux/dma-direct.h>
  30 #include <asm/iommu.h>
  31
  32 #define STA2X11_SWIOTLB_SIZE (4*1024*1024)
  33 extern int swiotlb_late_init_with_default_size(size_t default_size);
  34
  35 /*
  36  * We build a list of bus numbers that are under the ConneXt. The
  37  * main bridge hosts 4 busses, which are the 4 endpoints, in order.
  38  */
  39 #define STA2X11_NR_EP           4       /* 0..3 included */
  40 #define STA2X11_NR_FUNCS        8       /* 0..7 included */
  41 #define STA2X11_AMBA_SIZE       (512 << 20)
  42
  43 struct sta2x11_ahb_regs { /* saved during suspend */
  44         u32 base, pexlbase, pexhbase, crw;
  45 };
  46
  47 struct sta2x11_mapping {
  48         u32 amba_base;
  49         int is_suspended;
  50         struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS];
  51 };
  52
  53 struct sta2x11_instance {
  54         struct list_head list;
  55         int bus0;
  56         struct sta2x11_mapping map[STA2X11_NR_EP];
  57 };
  58
  59 static LIST_HEAD(sta2x11_instance_list);
  60
  61 /* At probe time, record new instances of this bridge (likely one only) */
  62 static void sta2x11_new_instance(struct pci_dev *pdev)
  63 {
  64         struct sta2x11_instance *instance;
  65
  66         instance = kzalloc(sizeof(*instance), GFP_ATOMIC);
  67         if (!instance)
  68                 return;
  69         /* This has a subordinate bridge, with 4 more-subordinate ones */
  70         instance->bus0 = pdev->subordinate->number + 1;
  71
  72         if (list_empty(&sta2x11_instance_list)) {
  73                 int size = STA2X11_SWIOTLB_SIZE;
  74                 /* First instance: register your own swiotlb area */
  75                 dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size);
  76                 if (swiotlb_late_init_with_default_size(size))
  77                         dev_emerg(&pdev->dev, "init swiotlb failed\n");
  78         }
  79         list_add(&instance->list, &sta2x11_instance_list);
  80 }
  81 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance);
  82
  83 /*
  84  * Utility functions used in this file from below
  85  */
  86 static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev)
  87 {
  88         struct sta2x11_instance *instance;
  89         int ep;
  90
  91         list_for_each_entry(instance, &sta2x11_instance_list, list) {
  92                 ep = pdev->bus->number - instance->bus0;
  93                 if (ep >= 0 && ep < STA2X11_NR_EP)
  94                         return instance;
  95         }
  96         return NULL;
  97 }
  98
  99 static int sta2x11_pdev_to_ep(struct pci_dev *pdev)
 100 {
 101         struct sta2x11_instance *instance;
 102
 103         instance = sta2x11_pdev_to_instance(pdev);
 104         if (!instance)
 105                 return -1;
 106
 107         return pdev->bus->number - instance->bus0;
 108 }
 109
 110 static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev)
 111 {
 112         struct sta2x11_instance *instance;
 113         int ep;
 114
 115         instance = sta2x11_pdev_to_instance(pdev);
 116         if (!instance)
 117                 return NULL;
 118         ep = sta2x11_pdev_to_ep(pdev);
 119         return instance->map + ep;
 120 }
 121
 122 /* This is exported, as some devices need to access the MFD registers */
 123 struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev)
 124 {
 125         return sta2x11_pdev_to_instance(pdev);
 126 }
 127 EXPORT_SYMBOL(sta2x11_get_instance);
 128
 129
 130 /**
 131  * p2a - Translate physical address to STA2x11 AMBA address,
 132  *       used for DMA transfers to STA2x11
 133  * @p: Physical address
 134  * @pdev: PCI device (must be hosted within the connext)
 135  */
 136 static dma_addr_t p2a(dma_addr_t p, struct pci_dev *pdev)
 137 {
 138         struct sta2x11_mapping *map;
 139         dma_addr_t a;
 140
 141         map = sta2x11_pdev_to_mapping(pdev);
 142         a = p + map->amba_base;
 143         return a;
 144 }
 145
 146 /**
 147  * a2p - Translate STA2x11 AMBA address to physical address
 148  *       used for DMA transfers from STA2x11
 149  * @a: STA2x11 AMBA address
 150  * @pdev: PCI device (must be hosted within the connext)
 151  */
 152 static dma_addr_t a2p(dma_addr_t a, struct pci_dev *pdev)
 153 {
 154         struct sta2x11_mapping *map;
 155         dma_addr_t p;
 156
 157         map = sta2x11_pdev_to_mapping(pdev);
 158         p = a - map->amba_base;
 159         return p;
 160 }
 161
 162 /**
 163  * sta2x11_swiotlb_alloc_coherent - Allocate swiotlb bounce buffers
 164  *     returns virtual address. This is the only "special" function here.
 165  * @dev: PCI device
 166  * @size: Size of the buffer
 167  * @dma_handle: DMA address
 168  * @flags: memory flags
 169  */
 170 static void *sta2x11_swiotlb_alloc_coherent(struct device *dev,
 171                                             size_t size,
 172                                             dma_addr_t *dma_handle,
 173                                             gfp_t flags,
 174                                             unsigned long attrs)
 175 {
 176         void *vaddr;
 177
 178         vaddr = x86_swiotlb_alloc_coherent(dev, size, dma_handle, flags, attrs);
 179         *dma_handle = p2a(*dma_handle, to_pci_dev(dev));
 180         return vaddr;
 181 }
 182
 183 /* We have our own dma_ops: the same as swiotlb but from alloc (above) */
 184 static const struct dma_map_ops sta2x11_dma_ops = {
 185         .alloc = sta2x11_swiotlb_alloc_coherent,
 186         .free = x86_swiotlb_free_coherent,
 187         .map_page = swiotlb_map_page,
 188         .unmap_page = swiotlb_unmap_page,
 189         .map_sg = swiotlb_map_sg_attrs,
 190         .unmap_sg = swiotlb_unmap_sg_attrs,
 191         .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
 192         .sync_single_for_device = swiotlb_sync_single_for_device,
 193         .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
 194         .sync_sg_for_device = swiotlb_sync_sg_for_device,
 195         .mapping_error = swiotlb_dma_mapping_error,
 196         .dma_supported = x86_dma_supported,
 197 };
 198
 199 /* At setup time, we use our own ops if the device is a ConneXt one */
 200 static void sta2x11_setup_pdev(struct pci_dev *pdev)
 201 {
 202         struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);
 203
 204         if (!instance) /* either a sta2x11 bridge or another ST device */
 205                 return;
 206         pci_set_consistent_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
 207         pci_set_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
 208         pdev->dev.dma_ops = &sta2x11_dma_ops;
 209
 210         /* We must enable all devices as master, for audio DMA to work */
 211         pci_set_master(pdev);
 212 }
 213 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev);
 214
 215 /*
 216  * The following three functions are exported (used in swiotlb: FIXME)
 217  */
 218 /**
 219  * dma_capable - Check if device can manage DMA transfers (FIXME: kill it)
 220  * @dev: device for a PCI device
 221  * @addr: DMA address
 222  * @size: DMA size
 223  */
 224 bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
 225 {
 226         struct sta2x11_mapping *map;
 227
 228         if (dev->dma_ops != &sta2x11_dma_ops) {
 229                 if (!dev->dma_mask)
 230                         return false;
 231                 return addr + size - 1 <= *dev->dma_mask;
 232         }
 233
 234         map = sta2x11_pdev_to_mapping(to_pci_dev(dev));
 235
 236         if (!map || (addr < map->amba_base))
 237                 return false;
 238         if (addr + size >= map->amba_base + STA2X11_AMBA_SIZE) {
 239                 return false;
 240         }
 241
 242         return true;
 243 }
 244
 245 /**
 246  * phys_to_dma - Return the DMA AMBA address used for this STA2x11 device
 247  * @dev: device for a PCI device
 248  * @paddr: Physical address
 249  */
 250 dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
 251 {
 252         if (dev->dma_ops != &sta2x11_dma_ops)
 253                 return paddr;
 254         return p2a(paddr, to_pci_dev(dev));
 255 }
 256
 257 /**
 258  * dma_to_phys - Return the physical address used for this STA2x11 DMA address
 259  * @dev: device for a PCI device
 260  * @daddr: STA2x11 AMBA DMA address
 261  */
 262 phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
 263 {
 264         if (dev->dma_ops != &sta2x11_dma_ops)
 265                 return daddr;
 266         return a2p(daddr, to_pci_dev(dev));
 267 }
 268
 269
 270 /*
 271  * At boot we must set up the mappings for the pcie-to-amba bridge.
 272  * It involves device access, and the same happens at suspend/resume time
 273  */
 274
 275 #define AHB_MAPB                0xCA4
 276 #define AHB_CRW(i)              (AHB_MAPB + 0  + (i) * 0x10)
 277 #define AHB_CRW_SZMASK                  0xfffffc00UL
 278 #define AHB_CRW_ENABLE                  (1 << 0)
 279 #define AHB_CRW_WTYPE_MEM               (2 << 1)
 280 #define AHB_CRW_ROE                     (1UL << 3)      /* Relax Order Ena */
 281 #define AHB_CRW_NSE                     (1UL << 4)      /* No Snoop Enable */
 282 #define AHB_BASE(i)             (AHB_MAPB + 4  + (i) * 0x10)
 283 #define AHB_PEXLBASE(i)         (AHB_MAPB + 8  + (i) * 0x10)
 284 #define AHB_PEXHBASE(i)         (AHB_MAPB + 12 + (i) * 0x10)
 285
 286 /* At probe time, enable mapping for each endpoint, using the pdev */
 287 static void sta2x11_map_ep(struct pci_dev *pdev)
 288 {
 289         struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
 290         int i;
 291
 292         if (!map)
 293                 return;
 294         pci_read_config_dword(pdev, AHB_BASE(0), &map->amba_base);
 295
 296         /* Configure AHB mapping */
 297         pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0);
 298         pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0);
 299         pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE |
 300                                AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE);
 301
 302         /* Disable all the other windows */
 303         for (i = 1; i < STA2X11_NR_FUNCS; i++)
 304                 pci_write_config_dword(pdev, AHB_CRW(i), 0);
 305
 306         dev_info(&pdev->dev,
 307                  "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n",
 308                  sta2x11_pdev_to_ep(pdev),  map->amba_base,
 309                  map->amba_base + STA2X11_AMBA_SIZE - 1);
 310 }
 311 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep);
 312
 313 #ifdef CONFIG_PM /* Some register values must be saved and restored */
 314
 315 static void suspend_mapping(struct pci_dev *pdev)
 316 {
 317         struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
 318         int i;
 319
 320         if (!map)
 321                 return;
 322
 323         if (map->is_suspended)
 324                 return;
 325         map->is_suspended = 1;
 326
 327         /* Save all window configs */
 328         for (i = 0; i < STA2X11_NR_FUNCS; i++) {
 329                 struct sta2x11_ahb_regs *regs = map->regs + i;
 330
 331                 pci_read_config_dword(pdev, AHB_BASE(i), &regs->base);
 332                 pci_read_config_dword(pdev, AHB_PEXLBASE(i), &regs->pexlbase);
 333                 pci_read_config_dword(pdev, AHB_PEXHBASE(i), &regs->pexhbase);
 334                 pci_read_config_dword(pdev, AHB_CRW(i), &regs->crw);
 335         }
 336 }
 337 DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping);
 338
 339 static void resume_mapping(struct pci_dev *pdev)
 340 {
 341         struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
 342         int i;
 343
 344         if (!map)
 345                 return;
 346
 347
 348         if (!map->is_suspended)
 349                 goto out;
 350         map->is_suspended = 0;
 351
 352         /* Restore all window configs */
 353         for (i = 0; i < STA2X11_NR_FUNCS; i++) {
 354                 struct sta2x11_ahb_regs *regs = map->regs + i;
 355
 356                 pci_write_config_dword(pdev, AHB_BASE(i), regs->base);
 357                 pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase);
 358                 pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase);
 359                 pci_write_config_dword(pdev, AHB_CRW(i), regs->crw);
 360         }
 361 out:
 362         pci_set_master(pdev); /* Like at boot, enable master on all devices */
 363 }
 364 DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping);
 365
 366 #endif /* CONFIG_PM */