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