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), ®s->base); 331 pci_read_config_dword(pdev, AHB_PEXLBASE(i), ®s->pexlbase); 332 pci_read_config_dword(pdev, AHB_PEXHBASE(i), ®s->pexhbase); 333 pci_read_config_dword(pdev, AHB_CRW(i), ®s->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 */ 366