1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * APM X-Gene PCIe Driver 4 * 5 * Copyright (c) 2014 Applied Micro Circuits Corporation. 6 * 7 * Author: Tanmay Inamdar <tinamdar@apm.com>. 8 */ 9 #include <linux/clk.h> 10 #include <linux/delay.h> 11 #include <linux/io.h> 12 #include <linux/jiffies.h> 13 #include <linux/memblock.h> 14 #include <linux/init.h> 15 #include <linux/of.h> 16 #include <linux/of_address.h> 17 #include <linux/of_irq.h> 18 #include <linux/of_pci.h> 19 #include <linux/pci.h> 20 #include <linux/pci-acpi.h> 21 #include <linux/pci-ecam.h> 22 #include <linux/platform_device.h> 23 #include <linux/slab.h> 24 25 #include "../pci.h" 26 27 #define PCIECORE_CTLANDSTATUS 0x50 28 #define PIM1_1L 0x80 29 #define IBAR2 0x98 30 #define IR2MSK 0x9c 31 #define PIM2_1L 0xa0 32 #define IBAR3L 0xb4 33 #define IR3MSKL 0xbc 34 #define PIM3_1L 0xc4 35 #define OMR1BARL 0x100 36 #define OMR2BARL 0x118 37 #define OMR3BARL 0x130 38 #define CFGBARL 0x154 39 #define CFGBARH 0x158 40 #define CFGCTL 0x15c 41 #define RTDID 0x160 42 #define BRIDGE_CFG_0 0x2000 43 #define BRIDGE_CFG_4 0x2010 44 #define BRIDGE_STATUS_0 0x2600 45 46 #define LINK_UP_MASK 0x00000100 47 #define AXI_EP_CFG_ACCESS 0x10000 48 #define EN_COHERENCY 0xF0000000 49 #define EN_REG 0x00000001 50 #define OB_LO_IO 0x00000002 51 #define XGENE_PCIE_DEVICEID 0xE004 52 #define SZ_1T (SZ_1G*1024ULL) 53 #define PIPE_PHY_RATE_RD(src) ((0xc000 & (u32)(src)) >> 0xe) 54 55 #define XGENE_V1_PCI_EXP_CAP 0x40 56 57 /* PCIe IP version */ 58 #define XGENE_PCIE_IP_VER_UNKN 0 59 #define XGENE_PCIE_IP_VER_1 1 60 #define XGENE_PCIE_IP_VER_2 2 61 62 #if defined(CONFIG_PCI_XGENE) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)) 63 struct xgene_pcie_port { 64 struct device_node *node; 65 struct device *dev; 66 struct clk *clk; 67 void __iomem *csr_base; 68 void __iomem *cfg_base; 69 unsigned long cfg_addr; 70 bool link_up; 71 u32 version; 72 }; 73 74 static u32 xgene_pcie_readl(struct xgene_pcie_port *port, u32 reg) 75 { 76 return readl(port->csr_base + reg); 77 } 78 79 static void xgene_pcie_writel(struct xgene_pcie_port *port, u32 reg, u32 val) 80 { 81 writel(val, port->csr_base + reg); 82 } 83 84 static inline u32 pcie_bar_low_val(u32 addr, u32 flags) 85 { 86 return (addr & PCI_BASE_ADDRESS_MEM_MASK) | flags; 87 } 88 89 static inline struct xgene_pcie_port *pcie_bus_to_port(struct pci_bus *bus) 90 { 91 struct pci_config_window *cfg; 92 93 if (acpi_disabled) 94 return (struct xgene_pcie_port *)(bus->sysdata); 95 96 cfg = bus->sysdata; 97 return (struct xgene_pcie_port *)(cfg->priv); 98 } 99 100 /* 101 * When the address bit [17:16] is 2'b01, the Configuration access will be 102 * treated as Type 1 and it will be forwarded to external PCIe device. 103 */ 104 static void __iomem *xgene_pcie_get_cfg_base(struct pci_bus *bus) 105 { 106 struct xgene_pcie_port *port = pcie_bus_to_port(bus); 107 108 if (bus->number >= (bus->primary + 1)) 109 return port->cfg_base + AXI_EP_CFG_ACCESS; 110 111 return port->cfg_base; 112 } 113 114 /* 115 * For Configuration request, RTDID register is used as Bus Number, 116 * Device Number and Function number of the header fields. 117 */ 118 static void xgene_pcie_set_rtdid_reg(struct pci_bus *bus, uint devfn) 119 { 120 struct xgene_pcie_port *port = pcie_bus_to_port(bus); 121 unsigned int b, d, f; 122 u32 rtdid_val = 0; 123 124 b = bus->number; 125 d = PCI_SLOT(devfn); 126 f = PCI_FUNC(devfn); 127 128 if (!pci_is_root_bus(bus)) 129 rtdid_val = (b << 8) | (d << 3) | f; 130 131 xgene_pcie_writel(port, RTDID, rtdid_val); 132 /* read the register back to ensure flush */ 133 xgene_pcie_readl(port, RTDID); 134 } 135 136 /* 137 * X-Gene PCIe port uses BAR0-BAR1 of RC's configuration space as 138 * the translation from PCI bus to native BUS. Entire DDR region 139 * is mapped into PCIe space using these registers, so it can be 140 * reached by DMA from EP devices. The BAR0/1 of bridge should be 141 * hidden during enumeration to avoid the sizing and resource allocation 142 * by PCIe core. 143 */ 144 static bool xgene_pcie_hide_rc_bars(struct pci_bus *bus, int offset) 145 { 146 if (pci_is_root_bus(bus) && ((offset == PCI_BASE_ADDRESS_0) || 147 (offset == PCI_BASE_ADDRESS_1))) 148 return true; 149 150 return false; 151 } 152 153 static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn, 154 int offset) 155 { 156 if ((pci_is_root_bus(bus) && devfn != 0) || 157 xgene_pcie_hide_rc_bars(bus, offset)) 158 return NULL; 159 160 xgene_pcie_set_rtdid_reg(bus, devfn); 161 return xgene_pcie_get_cfg_base(bus) + offset; 162 } 163 164 static int xgene_pcie_config_read32(struct pci_bus *bus, unsigned int devfn, 165 int where, int size, u32 *val) 166 { 167 struct xgene_pcie_port *port = pcie_bus_to_port(bus); 168 169 if (pci_generic_config_read32(bus, devfn, where & ~0x3, 4, val) != 170 PCIBIOS_SUCCESSFUL) 171 return PCIBIOS_DEVICE_NOT_FOUND; 172 173 /* 174 * The v1 controller has a bug in its Configuration Request 175 * Retry Status (CRS) logic: when CRS Software Visibility is 176 * enabled and we read the Vendor and Device ID of a non-existent 177 * device, the controller fabricates return data of 0xFFFF0001 178 * ("device exists but is not ready") instead of 0xFFFFFFFF 179 * ("device does not exist"). This causes the PCI core to retry 180 * the read until it times out. Avoid this by not claiming to 181 * support CRS SV. 182 */ 183 if (pci_is_root_bus(bus) && (port->version == XGENE_PCIE_IP_VER_1) && 184 ((where & ~0x3) == XGENE_V1_PCI_EXP_CAP + PCI_EXP_RTCTL)) 185 *val &= ~(PCI_EXP_RTCAP_CRSVIS << 16); 186 187 if (size <= 2) 188 *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1); 189 190 return PCIBIOS_SUCCESSFUL; 191 } 192 #endif 193 194 #if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) 195 static int xgene_get_csr_resource(struct acpi_device *adev, 196 struct resource *res) 197 { 198 struct device *dev = &adev->dev; 199 struct resource_entry *entry; 200 struct list_head list; 201 unsigned long flags; 202 int ret; 203 204 INIT_LIST_HEAD(&list); 205 flags = IORESOURCE_MEM; 206 ret = acpi_dev_get_resources(adev, &list, 207 acpi_dev_filter_resource_type_cb, 208 (void *) flags); 209 if (ret < 0) { 210 dev_err(dev, "failed to parse _CRS method, error code %d\n", 211 ret); 212 return ret; 213 } 214 215 if (ret == 0) { 216 dev_err(dev, "no IO and memory resources present in _CRS\n"); 217 return -EINVAL; 218 } 219 220 entry = list_first_entry(&list, struct resource_entry, node); 221 *res = *entry->res; 222 acpi_dev_free_resource_list(&list); 223 return 0; 224 } 225 226 static int xgene_pcie_ecam_init(struct pci_config_window *cfg, u32 ipversion) 227 { 228 struct device *dev = cfg->parent; 229 struct acpi_device *adev = to_acpi_device(dev); 230 struct xgene_pcie_port *port; 231 struct resource csr; 232 int ret; 233 234 port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL); 235 if (!port) 236 return -ENOMEM; 237 238 ret = xgene_get_csr_resource(adev, &csr); 239 if (ret) { 240 dev_err(dev, "can't get CSR resource\n"); 241 return ret; 242 } 243 port->csr_base = devm_pci_remap_cfg_resource(dev, &csr); 244 if (IS_ERR(port->csr_base)) 245 return PTR_ERR(port->csr_base); 246 247 port->cfg_base = cfg->win; 248 port->version = ipversion; 249 250 cfg->priv = port; 251 return 0; 252 } 253 254 static int xgene_v1_pcie_ecam_init(struct pci_config_window *cfg) 255 { 256 return xgene_pcie_ecam_init(cfg, XGENE_PCIE_IP_VER_1); 257 } 258 259 const struct pci_ecam_ops xgene_v1_pcie_ecam_ops = { 260 .init = xgene_v1_pcie_ecam_init, 261 .pci_ops = { 262 .map_bus = xgene_pcie_map_bus, 263 .read = xgene_pcie_config_read32, 264 .write = pci_generic_config_write, 265 } 266 }; 267 268 static int xgene_v2_pcie_ecam_init(struct pci_config_window *cfg) 269 { 270 return xgene_pcie_ecam_init(cfg, XGENE_PCIE_IP_VER_2); 271 } 272 273 const struct pci_ecam_ops xgene_v2_pcie_ecam_ops = { 274 .init = xgene_v2_pcie_ecam_init, 275 .pci_ops = { 276 .map_bus = xgene_pcie_map_bus, 277 .read = xgene_pcie_config_read32, 278 .write = pci_generic_config_write, 279 } 280 }; 281 #endif 282 283 #if defined(CONFIG_PCI_XGENE) 284 static u64 xgene_pcie_set_ib_mask(struct xgene_pcie_port *port, u32 addr, 285 u32 flags, u64 size) 286 { 287 u64 mask = (~(size - 1) & PCI_BASE_ADDRESS_MEM_MASK) | flags; 288 u32 val32 = 0; 289 u32 val; 290 291 val32 = xgene_pcie_readl(port, addr); 292 val = (val32 & 0x0000ffff) | (lower_32_bits(mask) << 16); 293 xgene_pcie_writel(port, addr, val); 294 295 val32 = xgene_pcie_readl(port, addr + 0x04); 296 val = (val32 & 0xffff0000) | (lower_32_bits(mask) >> 16); 297 xgene_pcie_writel(port, addr + 0x04, val); 298 299 val32 = xgene_pcie_readl(port, addr + 0x04); 300 val = (val32 & 0x0000ffff) | (upper_32_bits(mask) << 16); 301 xgene_pcie_writel(port, addr + 0x04, val); 302 303 val32 = xgene_pcie_readl(port, addr + 0x08); 304 val = (val32 & 0xffff0000) | (upper_32_bits(mask) >> 16); 305 xgene_pcie_writel(port, addr + 0x08, val); 306 307 return mask; 308 } 309 310 static void xgene_pcie_linkup(struct xgene_pcie_port *port, 311 u32 *lanes, u32 *speed) 312 { 313 u32 val32; 314 315 port->link_up = false; 316 val32 = xgene_pcie_readl(port, PCIECORE_CTLANDSTATUS); 317 if (val32 & LINK_UP_MASK) { 318 port->link_up = true; 319 *speed = PIPE_PHY_RATE_RD(val32); 320 val32 = xgene_pcie_readl(port, BRIDGE_STATUS_0); 321 *lanes = val32 >> 26; 322 } 323 } 324 325 static int xgene_pcie_init_port(struct xgene_pcie_port *port) 326 { 327 struct device *dev = port->dev; 328 int rc; 329 330 port->clk = clk_get(dev, NULL); 331 if (IS_ERR(port->clk)) { 332 dev_err(dev, "clock not available\n"); 333 return -ENODEV; 334 } 335 336 rc = clk_prepare_enable(port->clk); 337 if (rc) { 338 dev_err(dev, "clock enable failed\n"); 339 return rc; 340 } 341 342 return 0; 343 } 344 345 static int xgene_pcie_map_reg(struct xgene_pcie_port *port, 346 struct platform_device *pdev) 347 { 348 struct device *dev = port->dev; 349 struct resource *res; 350 351 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr"); 352 port->csr_base = devm_pci_remap_cfg_resource(dev, res); 353 if (IS_ERR(port->csr_base)) 354 return PTR_ERR(port->csr_base); 355 356 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg"); 357 port->cfg_base = devm_ioremap_resource(dev, res); 358 if (IS_ERR(port->cfg_base)) 359 return PTR_ERR(port->cfg_base); 360 port->cfg_addr = res->start; 361 362 return 0; 363 } 364 365 static void xgene_pcie_setup_ob_reg(struct xgene_pcie_port *port, 366 struct resource *res, u32 offset, 367 u64 cpu_addr, u64 pci_addr) 368 { 369 struct device *dev = port->dev; 370 resource_size_t size = resource_size(res); 371 u64 restype = resource_type(res); 372 u64 mask = 0; 373 u32 min_size; 374 u32 flag = EN_REG; 375 376 if (restype == IORESOURCE_MEM) { 377 min_size = SZ_128M; 378 } else { 379 min_size = 128; 380 flag |= OB_LO_IO; 381 } 382 383 if (size >= min_size) 384 mask = ~(size - 1) | flag; 385 else 386 dev_warn(dev, "res size 0x%llx less than minimum 0x%x\n", 387 (u64)size, min_size); 388 389 xgene_pcie_writel(port, offset, lower_32_bits(cpu_addr)); 390 xgene_pcie_writel(port, offset + 0x04, upper_32_bits(cpu_addr)); 391 xgene_pcie_writel(port, offset + 0x08, lower_32_bits(mask)); 392 xgene_pcie_writel(port, offset + 0x0c, upper_32_bits(mask)); 393 xgene_pcie_writel(port, offset + 0x10, lower_32_bits(pci_addr)); 394 xgene_pcie_writel(port, offset + 0x14, upper_32_bits(pci_addr)); 395 } 396 397 static void xgene_pcie_setup_cfg_reg(struct xgene_pcie_port *port) 398 { 399 u64 addr = port->cfg_addr; 400 401 xgene_pcie_writel(port, CFGBARL, lower_32_bits(addr)); 402 xgene_pcie_writel(port, CFGBARH, upper_32_bits(addr)); 403 xgene_pcie_writel(port, CFGCTL, EN_REG); 404 } 405 406 static int xgene_pcie_map_ranges(struct xgene_pcie_port *port) 407 { 408 struct pci_host_bridge *bridge = pci_host_bridge_from_priv(port); 409 struct resource_entry *window; 410 struct device *dev = port->dev; 411 412 resource_list_for_each_entry(window, &bridge->windows) { 413 struct resource *res = window->res; 414 u64 restype = resource_type(res); 415 416 dev_dbg(dev, "%pR\n", res); 417 418 switch (restype) { 419 case IORESOURCE_IO: 420 xgene_pcie_setup_ob_reg(port, res, OMR3BARL, 421 pci_pio_to_address(res->start), 422 res->start - window->offset); 423 break; 424 case IORESOURCE_MEM: 425 if (res->flags & IORESOURCE_PREFETCH) 426 xgene_pcie_setup_ob_reg(port, res, OMR2BARL, 427 res->start, 428 res->start - 429 window->offset); 430 else 431 xgene_pcie_setup_ob_reg(port, res, OMR1BARL, 432 res->start, 433 res->start - 434 window->offset); 435 break; 436 case IORESOURCE_BUS: 437 break; 438 default: 439 dev_err(dev, "invalid resource %pR\n", res); 440 return -EINVAL; 441 } 442 } 443 xgene_pcie_setup_cfg_reg(port); 444 return 0; 445 } 446 447 static void xgene_pcie_setup_pims(struct xgene_pcie_port *port, u32 pim_reg, 448 u64 pim, u64 size) 449 { 450 xgene_pcie_writel(port, pim_reg, lower_32_bits(pim)); 451 xgene_pcie_writel(port, pim_reg + 0x04, 452 upper_32_bits(pim) | EN_COHERENCY); 453 xgene_pcie_writel(port, pim_reg + 0x10, lower_32_bits(size)); 454 xgene_pcie_writel(port, pim_reg + 0x14, upper_32_bits(size)); 455 } 456 457 /* 458 * X-Gene PCIe support maximum 3 inbound memory regions 459 * This function helps to select a region based on size of region 460 */ 461 static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size) 462 { 463 if ((size > 4) && (size < SZ_16M) && !(*ib_reg_mask & (1 << 1))) { 464 *ib_reg_mask |= (1 << 1); 465 return 1; 466 } 467 468 if ((size > SZ_1K) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 0))) { 469 *ib_reg_mask |= (1 << 0); 470 return 0; 471 } 472 473 if ((size > SZ_1M) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 2))) { 474 *ib_reg_mask |= (1 << 2); 475 return 2; 476 } 477 478 return -EINVAL; 479 } 480 481 static void xgene_pcie_setup_ib_reg(struct xgene_pcie_port *port, 482 struct resource_entry *entry, 483 u8 *ib_reg_mask) 484 { 485 void __iomem *cfg_base = port->cfg_base; 486 struct device *dev = port->dev; 487 void __iomem *bar_addr; 488 u32 pim_reg; 489 u64 cpu_addr = entry->res->start; 490 u64 pci_addr = cpu_addr - entry->offset; 491 u64 size = resource_size(entry->res); 492 u64 mask = ~(size - 1) | EN_REG; 493 u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64; 494 u32 bar_low; 495 int region; 496 497 region = xgene_pcie_select_ib_reg(ib_reg_mask, size); 498 if (region < 0) { 499 dev_warn(dev, "invalid pcie dma-range config\n"); 500 return; 501 } 502 503 if (entry->res->flags & IORESOURCE_PREFETCH) 504 flags |= PCI_BASE_ADDRESS_MEM_PREFETCH; 505 506 bar_low = pcie_bar_low_val((u32)cpu_addr, flags); 507 switch (region) { 508 case 0: 509 xgene_pcie_set_ib_mask(port, BRIDGE_CFG_4, flags, size); 510 bar_addr = cfg_base + PCI_BASE_ADDRESS_0; 511 writel(bar_low, bar_addr); 512 writel(upper_32_bits(cpu_addr), bar_addr + 0x4); 513 pim_reg = PIM1_1L; 514 break; 515 case 1: 516 xgene_pcie_writel(port, IBAR2, bar_low); 517 xgene_pcie_writel(port, IR2MSK, lower_32_bits(mask)); 518 pim_reg = PIM2_1L; 519 break; 520 case 2: 521 xgene_pcie_writel(port, IBAR3L, bar_low); 522 xgene_pcie_writel(port, IBAR3L + 0x4, upper_32_bits(cpu_addr)); 523 xgene_pcie_writel(port, IR3MSKL, lower_32_bits(mask)); 524 xgene_pcie_writel(port, IR3MSKL + 0x4, upper_32_bits(mask)); 525 pim_reg = PIM3_1L; 526 break; 527 } 528 529 xgene_pcie_setup_pims(port, pim_reg, pci_addr, ~(size - 1)); 530 } 531 532 static int xgene_pcie_parse_map_dma_ranges(struct xgene_pcie_port *port) 533 { 534 struct pci_host_bridge *bridge = pci_host_bridge_from_priv(port); 535 struct resource_entry *entry; 536 u8 ib_reg_mask = 0; 537 538 resource_list_for_each_entry(entry, &bridge->dma_ranges) 539 xgene_pcie_setup_ib_reg(port, entry, &ib_reg_mask); 540 541 return 0; 542 } 543 544 /* clear BAR configuration which was done by firmware */ 545 static void xgene_pcie_clear_config(struct xgene_pcie_port *port) 546 { 547 int i; 548 549 for (i = PIM1_1L; i <= CFGCTL; i += 4) 550 xgene_pcie_writel(port, i, 0); 551 } 552 553 static int xgene_pcie_setup(struct xgene_pcie_port *port) 554 { 555 struct device *dev = port->dev; 556 u32 val, lanes = 0, speed = 0; 557 int ret; 558 559 xgene_pcie_clear_config(port); 560 561 /* setup the vendor and device IDs correctly */ 562 val = (XGENE_PCIE_DEVICEID << 16) | PCI_VENDOR_ID_AMCC; 563 xgene_pcie_writel(port, BRIDGE_CFG_0, val); 564 565 ret = xgene_pcie_map_ranges(port); 566 if (ret) 567 return ret; 568 569 ret = xgene_pcie_parse_map_dma_ranges(port); 570 if (ret) 571 return ret; 572 573 xgene_pcie_linkup(port, &lanes, &speed); 574 if (!port->link_up) 575 dev_info(dev, "(rc) link down\n"); 576 else 577 dev_info(dev, "(rc) x%d gen-%d link up\n", lanes, speed + 1); 578 return 0; 579 } 580 581 static struct pci_ops xgene_pcie_ops = { 582 .map_bus = xgene_pcie_map_bus, 583 .read = xgene_pcie_config_read32, 584 .write = pci_generic_config_write32, 585 }; 586 587 static int xgene_pcie_probe(struct platform_device *pdev) 588 { 589 struct device *dev = &pdev->dev; 590 struct device_node *dn = dev->of_node; 591 struct xgene_pcie_port *port; 592 struct pci_host_bridge *bridge; 593 int ret; 594 595 bridge = devm_pci_alloc_host_bridge(dev, sizeof(*port)); 596 if (!bridge) 597 return -ENOMEM; 598 599 port = pci_host_bridge_priv(bridge); 600 601 port->node = of_node_get(dn); 602 port->dev = dev; 603 604 port->version = XGENE_PCIE_IP_VER_UNKN; 605 if (of_device_is_compatible(port->node, "apm,xgene-pcie")) 606 port->version = XGENE_PCIE_IP_VER_1; 607 608 ret = xgene_pcie_map_reg(port, pdev); 609 if (ret) 610 return ret; 611 612 ret = xgene_pcie_init_port(port); 613 if (ret) 614 return ret; 615 616 ret = xgene_pcie_setup(port); 617 if (ret) 618 return ret; 619 620 bridge->sysdata = port; 621 bridge->ops = &xgene_pcie_ops; 622 623 return pci_host_probe(bridge); 624 } 625 626 static const struct of_device_id xgene_pcie_match_table[] = { 627 {.compatible = "apm,xgene-pcie",}, 628 {}, 629 }; 630 631 static struct platform_driver xgene_pcie_driver = { 632 .driver = { 633 .name = "xgene-pcie", 634 .of_match_table = of_match_ptr(xgene_pcie_match_table), 635 .suppress_bind_attrs = true, 636 }, 637 .probe = xgene_pcie_probe, 638 }; 639 builtin_platform_driver(xgene_pcie_driver); 640 #endif 641