1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2017 Cadence
3 // Cadence PCIe host controller driver.
6 #include <linux/delay.h>
7 #include <linux/kernel.h>
8 #include <linux/list_sort.h>
9 #include <linux/of_address.h>
10 #include <linux/of_pci.h>
11 #include <linux/platform_device.h>
13 #include "pcie-cadence.h"
15 #define LINK_RETRAIN_TIMEOUT HZ
17 static u64 bar_max_size[] = {
18 [RP_BAR0] = _ULL(128 * SZ_2G),
20 [RP_NO_BAR] = _BITULL(63),
23 static u8 bar_aperture_mask[] = {
28 void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
31 struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
32 struct cdns_pcie_rc *rc = pci_host_bridge_priv(bridge);
33 struct cdns_pcie *pcie = &rc->pcie;
34 unsigned int busn = bus->number;
37 if (pci_is_root_bus(bus)) {
39 * Only the root port (devfn == 0) is connected to this bus.
40 * All other PCI devices are behind some bridge hence on another
46 return pcie->reg_base + (where & 0xfff);
48 /* Check that the link is up */
49 if (!(cdns_pcie_readl(pcie, CDNS_PCIE_LM_BASE) & 0x1))
51 /* Clear AXI link-down status */
52 cdns_pcie_writel(pcie, CDNS_PCIE_AT_LINKDOWN, 0x0);
54 /* Update Output registers for AXI region 0. */
55 addr0 = CDNS_PCIE_AT_OB_REGION_PCI_ADDR0_NBITS(12) |
56 CDNS_PCIE_AT_OB_REGION_PCI_ADDR0_DEVFN(devfn) |
57 CDNS_PCIE_AT_OB_REGION_PCI_ADDR0_BUS(busn);
58 cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR0(0), addr0);
60 /* Configuration Type 0 or Type 1 access. */
61 desc0 = CDNS_PCIE_AT_OB_REGION_DESC0_HARDCODED_RID |
62 CDNS_PCIE_AT_OB_REGION_DESC0_DEVFN(0);
64 * The bus number was already set once for all in desc1 by
65 * cdns_pcie_host_init_address_translation().
67 if (busn == bridge->busnr + 1)
68 desc0 |= CDNS_PCIE_AT_OB_REGION_DESC0_TYPE_CONF_TYPE0;
70 desc0 |= CDNS_PCIE_AT_OB_REGION_DESC0_TYPE_CONF_TYPE1;
71 cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC0(0), desc0);
73 return rc->cfg_base + (where & 0xfff);
76 static struct pci_ops cdns_pcie_host_ops = {
77 .map_bus = cdns_pci_map_bus,
78 .read = pci_generic_config_read,
79 .write = pci_generic_config_write,
82 static int cdns_pcie_host_training_complete(struct cdns_pcie *pcie)
84 u32 pcie_cap_off = CDNS_PCIE_RP_CAP_OFFSET;
85 unsigned long end_jiffies;
88 /* Wait for link training to complete. Exit after timeout. */
89 end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT;
91 lnk_stat = cdns_pcie_rp_readw(pcie, pcie_cap_off + PCI_EXP_LNKSTA);
92 if (!(lnk_stat & PCI_EXP_LNKSTA_LT))
94 usleep_range(0, 1000);
95 } while (time_before(jiffies, end_jiffies));
97 if (!(lnk_stat & PCI_EXP_LNKSTA_LT))
103 static int cdns_pcie_host_wait_for_link(struct cdns_pcie *pcie)
105 struct device *dev = pcie->dev;
108 /* Check if the link is up or not */
109 for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
110 if (cdns_pcie_link_up(pcie)) {
111 dev_info(dev, "Link up\n");
114 usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX);
120 static int cdns_pcie_retrain(struct cdns_pcie *pcie)
122 u32 lnk_cap_sls, pcie_cap_off = CDNS_PCIE_RP_CAP_OFFSET;
123 u16 lnk_stat, lnk_ctl;
127 * Set retrain bit if current speed is 2.5 GB/s,
128 * but the PCIe root port support is > 2.5 GB/s.
131 lnk_cap_sls = cdns_pcie_readl(pcie, (CDNS_PCIE_RP_BASE + pcie_cap_off +
133 if ((lnk_cap_sls & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
136 lnk_stat = cdns_pcie_rp_readw(pcie, pcie_cap_off + PCI_EXP_LNKSTA);
137 if ((lnk_stat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB) {
138 lnk_ctl = cdns_pcie_rp_readw(pcie,
139 pcie_cap_off + PCI_EXP_LNKCTL);
140 lnk_ctl |= PCI_EXP_LNKCTL_RL;
141 cdns_pcie_rp_writew(pcie, pcie_cap_off + PCI_EXP_LNKCTL,
144 ret = cdns_pcie_host_training_complete(pcie);
148 ret = cdns_pcie_host_wait_for_link(pcie);
153 static void cdns_pcie_host_enable_ptm_response(struct cdns_pcie *pcie)
157 val = cdns_pcie_readl(pcie, CDNS_PCIE_LM_PTM_CTRL);
158 cdns_pcie_writel(pcie, CDNS_PCIE_LM_PTM_CTRL, val | CDNS_PCIE_LM_TPM_CTRL_PTMRSEN);
161 static int cdns_pcie_host_start_link(struct cdns_pcie_rc *rc)
163 struct cdns_pcie *pcie = &rc->pcie;
166 ret = cdns_pcie_host_wait_for_link(pcie);
169 * Retrain link for Gen2 training defect
170 * if quirk flag is set.
172 if (!ret && rc->quirk_retrain_flag)
173 ret = cdns_pcie_retrain(pcie);
178 static int cdns_pcie_host_init_root_port(struct cdns_pcie_rc *rc)
180 struct cdns_pcie *pcie = &rc->pcie;
185 * Set the root complex BAR configuration register:
186 * - disable both BAR0 and BAR1.
187 * - enable Prefetchable Memory Base and Limit registers in type 1
188 * config space (64 bits).
189 * - enable IO Base and Limit registers in type 1 config
192 ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED;
193 value = CDNS_PCIE_LM_RC_BAR_CFG_BAR0_CTRL(ctrl) |
194 CDNS_PCIE_LM_RC_BAR_CFG_BAR1_CTRL(ctrl) |
195 CDNS_PCIE_LM_RC_BAR_CFG_PREFETCH_MEM_ENABLE |
196 CDNS_PCIE_LM_RC_BAR_CFG_PREFETCH_MEM_64BITS |
197 CDNS_PCIE_LM_RC_BAR_CFG_IO_ENABLE |
198 CDNS_PCIE_LM_RC_BAR_CFG_IO_32BITS;
199 cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
201 /* Set root port configuration space */
202 if (rc->vendor_id != 0xffff) {
203 id = CDNS_PCIE_LM_ID_VENDOR(rc->vendor_id) |
204 CDNS_PCIE_LM_ID_SUBSYS(rc->vendor_id);
205 cdns_pcie_writel(pcie, CDNS_PCIE_LM_ID, id);
208 if (rc->device_id != 0xffff)
209 cdns_pcie_rp_writew(pcie, PCI_DEVICE_ID, rc->device_id);
211 cdns_pcie_rp_writeb(pcie, PCI_CLASS_REVISION, 0);
212 cdns_pcie_rp_writeb(pcie, PCI_CLASS_PROG, 0);
213 cdns_pcie_rp_writew(pcie, PCI_CLASS_DEVICE, PCI_CLASS_BRIDGE_PCI);
218 static int cdns_pcie_host_bar_ib_config(struct cdns_pcie_rc *rc,
219 enum cdns_pcie_rp_bar bar,
220 u64 cpu_addr, u64 size,
223 struct cdns_pcie *pcie = &rc->pcie;
224 u32 addr0, addr1, aperture, value;
226 if (!rc->avail_ib_bar[bar])
229 rc->avail_ib_bar[bar] = false;
231 aperture = ilog2(size);
232 addr0 = CDNS_PCIE_AT_IB_RP_BAR_ADDR0_NBITS(aperture) |
233 (lower_32_bits(cpu_addr) & GENMASK(31, 8));
234 addr1 = upper_32_bits(cpu_addr);
235 cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR0(bar), addr0);
236 cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR1(bar), addr1);
238 if (bar == RP_NO_BAR)
241 value = cdns_pcie_readl(pcie, CDNS_PCIE_LM_RC_BAR_CFG);
242 value &= ~(LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar) |
243 LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar) |
244 LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar) |
245 LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar) |
246 LM_RC_BAR_CFG_APERTURE(bar, bar_aperture_mask[bar] + 2));
247 if (size + cpu_addr >= SZ_4G) {
248 if (!(flags & IORESOURCE_PREFETCH))
249 value |= LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar);
250 value |= LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar);
252 if (!(flags & IORESOURCE_PREFETCH))
253 value |= LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar);
254 value |= LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar);
257 value |= LM_RC_BAR_CFG_APERTURE(bar, aperture);
258 cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
263 static enum cdns_pcie_rp_bar
264 cdns_pcie_host_find_min_bar(struct cdns_pcie_rc *rc, u64 size)
266 enum cdns_pcie_rp_bar bar, sel_bar;
268 sel_bar = RP_BAR_UNDEFINED;
269 for (bar = RP_BAR0; bar <= RP_NO_BAR; bar++) {
270 if (!rc->avail_ib_bar[bar])
273 if (size <= bar_max_size[bar]) {
274 if (sel_bar == RP_BAR_UNDEFINED) {
279 if (bar_max_size[bar] < bar_max_size[sel_bar])
287 static enum cdns_pcie_rp_bar
288 cdns_pcie_host_find_max_bar(struct cdns_pcie_rc *rc, u64 size)
290 enum cdns_pcie_rp_bar bar, sel_bar;
292 sel_bar = RP_BAR_UNDEFINED;
293 for (bar = RP_BAR0; bar <= RP_NO_BAR; bar++) {
294 if (!rc->avail_ib_bar[bar])
297 if (size >= bar_max_size[bar]) {
298 if (sel_bar == RP_BAR_UNDEFINED) {
303 if (bar_max_size[bar] > bar_max_size[sel_bar])
311 static int cdns_pcie_host_bar_config(struct cdns_pcie_rc *rc,
312 struct resource_entry *entry)
314 u64 cpu_addr, pci_addr, size, winsize;
315 struct cdns_pcie *pcie = &rc->pcie;
316 struct device *dev = pcie->dev;
317 enum cdns_pcie_rp_bar bar;
321 cpu_addr = entry->res->start;
322 pci_addr = entry->res->start - entry->offset;
323 flags = entry->res->flags;
324 size = resource_size(entry->res);
327 dev_err(dev, "PCI addr: %llx must be equal to CPU addr: %llx\n",
334 * Try to find a minimum BAR whose size is greater than
335 * or equal to the remaining resource_entry size. This will
336 * fail if the size of each of the available BARs is less than
337 * the remaining resource_entry size.
338 * If a minimum BAR is found, IB ATU will be configured and
341 bar = cdns_pcie_host_find_min_bar(rc, size);
342 if (bar != RP_BAR_UNDEFINED) {
343 ret = cdns_pcie_host_bar_ib_config(rc, bar, cpu_addr,
346 dev_err(dev, "IB BAR: %d config failed\n", bar);
351 * If the control reaches here, it would mean the remaining
352 * resource_entry size cannot be fitted in a single BAR. So we
353 * find a maximum BAR whose size is less than or equal to the
354 * remaining resource_entry size and split the resource entry
355 * so that part of resource entry is fitted inside the maximum
356 * BAR. The remaining size would be fitted during the next
357 * iteration of the loop.
358 * If a maximum BAR is not found, there is no way we can fit
359 * this resource_entry, so we error out.
361 bar = cdns_pcie_host_find_max_bar(rc, size);
362 if (bar == RP_BAR_UNDEFINED) {
363 dev_err(dev, "No free BAR to map cpu_addr %llx\n",
368 winsize = bar_max_size[bar];
369 ret = cdns_pcie_host_bar_ib_config(rc, bar, cpu_addr, winsize,
372 dev_err(dev, "IB BAR: %d config failed\n", bar);
383 static int cdns_pcie_host_dma_ranges_cmp(void *priv, const struct list_head *a,
384 const struct list_head *b)
386 struct resource_entry *entry1, *entry2;
388 entry1 = container_of(a, struct resource_entry, node);
389 entry2 = container_of(b, struct resource_entry, node);
391 return resource_size(entry2->res) - resource_size(entry1->res);
394 static int cdns_pcie_host_map_dma_ranges(struct cdns_pcie_rc *rc)
396 struct cdns_pcie *pcie = &rc->pcie;
397 struct device *dev = pcie->dev;
398 struct device_node *np = dev->of_node;
399 struct pci_host_bridge *bridge;
400 struct resource_entry *entry;
401 u32 no_bar_nbits = 32;
404 bridge = pci_host_bridge_from_priv(rc);
408 if (list_empty(&bridge->dma_ranges)) {
409 of_property_read_u32(np, "cdns,no-bar-match-nbits",
411 err = cdns_pcie_host_bar_ib_config(rc, RP_NO_BAR, 0x0,
412 (u64)1 << no_bar_nbits, 0);
414 dev_err(dev, "IB BAR: %d config failed\n", RP_NO_BAR);
418 list_sort(NULL, &bridge->dma_ranges, cdns_pcie_host_dma_ranges_cmp);
420 resource_list_for_each_entry(entry, &bridge->dma_ranges) {
421 err = cdns_pcie_host_bar_config(rc, entry);
423 dev_err(dev, "Fail to configure IB using dma-ranges\n");
431 static int cdns_pcie_host_init_address_translation(struct cdns_pcie_rc *rc)
433 struct cdns_pcie *pcie = &rc->pcie;
434 struct pci_host_bridge *bridge = pci_host_bridge_from_priv(rc);
435 struct resource *cfg_res = rc->cfg_res;
436 struct resource_entry *entry;
437 u64 cpu_addr = cfg_res->start;
438 u32 addr0, addr1, desc1;
441 entry = resource_list_first_type(&bridge->windows, IORESOURCE_BUS);
443 busnr = entry->res->start;
446 * Reserve region 0 for PCI configure space accesses:
447 * OB_REGION_PCI_ADDR0 and OB_REGION_DESC0 are updated dynamically by
448 * cdns_pci_map_bus(), other region registers are set here once for all.
450 addr1 = 0; /* Should be programmed to zero. */
451 desc1 = CDNS_PCIE_AT_OB_REGION_DESC1_BUS(busnr);
452 cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR1(0), addr1);
453 cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC1(0), desc1);
455 if (pcie->ops->cpu_addr_fixup)
456 cpu_addr = pcie->ops->cpu_addr_fixup(pcie, cpu_addr);
458 addr0 = CDNS_PCIE_AT_OB_REGION_CPU_ADDR0_NBITS(12) |
459 (lower_32_bits(cpu_addr) & GENMASK(31, 8));
460 addr1 = upper_32_bits(cpu_addr);
461 cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR0(0), addr0);
462 cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR1(0), addr1);
465 resource_list_for_each_entry(entry, &bridge->windows) {
466 struct resource *res = entry->res;
467 u64 pci_addr = res->start - entry->offset;
469 if (resource_type(res) == IORESOURCE_IO)
470 cdns_pcie_set_outbound_region(pcie, busnr, 0, r,
472 pci_pio_to_address(res->start),
476 cdns_pcie_set_outbound_region(pcie, busnr, 0, r,
485 return cdns_pcie_host_map_dma_ranges(rc);
488 int cdns_pcie_host_init(struct cdns_pcie_rc *rc)
492 err = cdns_pcie_host_init_root_port(rc);
496 return cdns_pcie_host_init_address_translation(rc);
499 int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc)
501 struct cdns_pcie *pcie = &rc->pcie;
502 struct device *dev = rc->pcie.dev;
505 if (rc->quirk_detect_quiet_flag)
506 cdns_pcie_detect_quiet_min_delay_set(&rc->pcie);
508 cdns_pcie_host_enable_ptm_response(pcie);
510 ret = cdns_pcie_start_link(pcie);
512 dev_err(dev, "Failed to start link\n");
516 ret = cdns_pcie_host_start_link(rc);
518 dev_dbg(dev, "PCIe link never came up\n");
523 int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
525 struct device *dev = rc->pcie.dev;
526 struct platform_device *pdev = to_platform_device(dev);
527 struct device_node *np = dev->of_node;
528 struct pci_host_bridge *bridge;
529 enum cdns_pcie_rp_bar bar;
530 struct cdns_pcie *pcie;
531 struct resource *res;
534 bridge = pci_host_bridge_from_priv(rc);
541 rc->vendor_id = 0xffff;
542 of_property_read_u32(np, "vendor-id", &rc->vendor_id);
544 rc->device_id = 0xffff;
545 of_property_read_u32(np, "device-id", &rc->device_id);
547 pcie->reg_base = devm_platform_ioremap_resource_byname(pdev, "reg");
548 if (IS_ERR(pcie->reg_base)) {
549 dev_err(dev, "missing \"reg\"\n");
550 return PTR_ERR(pcie->reg_base);
553 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
554 rc->cfg_base = devm_pci_remap_cfg_resource(dev, res);
555 if (IS_ERR(rc->cfg_base))
556 return PTR_ERR(rc->cfg_base);
559 ret = cdns_pcie_host_link_setup(rc);
563 for (bar = RP_BAR0; bar <= RP_NO_BAR; bar++)
564 rc->avail_ib_bar[bar] = true;
566 ret = cdns_pcie_host_init(rc);
571 bridge->ops = &cdns_pcie_host_ops;
573 ret = pci_host_probe(bridge);
580 pm_runtime_put_sync(dev);