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_pci.h>
18#include <linux/pci.h>
19#include <linux/pci-acpi.h>
20#include <linux/pci-ecam.h>
21#include <linux/platform_device.h>
22#include <linux/slab.h>
23
24#include "../pci.h"
25
26#define PCIECORE_CTLANDSTATUS 0x50
27#define PIM1_1L 0x80
28#define IBAR2 0x98
29#define IR2MSK 0x9c
30#define PIM2_1L 0xa0
31#define IBAR3L 0xb4
32#define IR3MSKL 0xbc
33#define PIM3_1L 0xc4
34#define OMR1BARL 0x100
35#define OMR2BARL 0x118
36#define OMR3BARL 0x130
37#define CFGBARL 0x154
38#define CFGBARH 0x158
39#define CFGCTL 0x15c
40#define RTDID 0x160
41#define BRIDGE_CFG_0 0x2000
42#define BRIDGE_CFG_4 0x2010
43#define BRIDGE_STATUS_0 0x2600
44
45#define LINK_UP_MASK 0x00000100
46#define AXI_EP_CFG_ACCESS 0x10000
47#define EN_COHERENCY 0xF0000000
48#define EN_REG 0x00000001
49#define OB_LO_IO 0x00000002
50#define XGENE_PCIE_DEVICEID 0xE004
51#define PIPE_PHY_RATE_RD(src) ((0xc000 & (u32)(src)) >> 0xe)
52
53#define XGENE_V1_PCI_EXP_CAP 0x40
54
55/* PCIe IP version */
56#define XGENE_PCIE_IP_VER_UNKN 0
57#define XGENE_PCIE_IP_VER_1 1
58#define XGENE_PCIE_IP_VER_2 2
59
60#if defined(CONFIG_PCI_XGENE) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
61struct xgene_pcie {
62 struct device_node *node;
63 struct device *dev;
64 struct clk *clk;
65 void __iomem *csr_base;
66 void __iomem *cfg_base;
67 unsigned long cfg_addr;
68 bool link_up;
69 u32 version;
70};
71
72static u32 xgene_pcie_readl(struct xgene_pcie *port, u32 reg)
73{
74 return readl(addr: port->csr_base + reg);
75}
76
77static void xgene_pcie_writel(struct xgene_pcie *port, u32 reg, u32 val)
78{
79 writel(val, addr: port->csr_base + reg);
80}
81
82static inline u32 pcie_bar_low_val(u32 addr, u32 flags)
83{
84 return (addr & PCI_BASE_ADDRESS_MEM_MASK) | flags;
85}
86
87static inline struct xgene_pcie *pcie_bus_to_port(struct pci_bus *bus)
88{
89 struct pci_config_window *cfg;
90
91 if (acpi_disabled)
92 return (struct xgene_pcie *)(bus->sysdata);
93
94 cfg = bus->sysdata;
95 return (struct xgene_pcie *)(cfg->priv);
96}
97
98/*
99 * When the address bit [17:16] is 2'b01, the Configuration access will be
100 * treated as Type 1 and it will be forwarded to external PCIe device.
101 */
102static void __iomem *xgene_pcie_get_cfg_base(struct pci_bus *bus)
103{
104 struct xgene_pcie *port = pcie_bus_to_port(bus);
105
106 if (bus->number >= (bus->primary + 1))
107 return port->cfg_base + AXI_EP_CFG_ACCESS;
108
109 return port->cfg_base;
110}
111
112/*
113 * For Configuration request, RTDID register is used as Bus Number,
114 * Device Number and Function number of the header fields.
115 */
116static void xgene_pcie_set_rtdid_reg(struct pci_bus *bus, uint devfn)
117{
118 struct xgene_pcie *port = pcie_bus_to_port(bus);
119 unsigned int b, d, f;
120 u32 rtdid_val = 0;
121
122 b = bus->number;
123 d = PCI_SLOT(devfn);
124 f = PCI_FUNC(devfn);
125
126 if (!pci_is_root_bus(pbus: bus))
127 rtdid_val = (b << 8) | (d << 3) | f;
128
129 xgene_pcie_writel(port, RTDID, val: rtdid_val);
130 /* read the register back to ensure flush */
131 xgene_pcie_readl(port, RTDID);
132}
133
134/*
135 * X-Gene PCIe port uses BAR0-BAR1 of RC's configuration space as
136 * the translation from PCI bus to native BUS. Entire DDR region
137 * is mapped into PCIe space using these registers, so it can be
138 * reached by DMA from EP devices. The BAR0/1 of bridge should be
139 * hidden during enumeration to avoid the sizing and resource allocation
140 * by PCIe core.
141 */
142static bool xgene_pcie_hide_rc_bars(struct pci_bus *bus, int offset)
143{
144 if (pci_is_root_bus(pbus: bus) && ((offset == PCI_BASE_ADDRESS_0) ||
145 (offset == PCI_BASE_ADDRESS_1)))
146 return true;
147
148 return false;
149}
150
151static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
152 int offset)
153{
154 if ((pci_is_root_bus(pbus: bus) && devfn != 0) ||
155 xgene_pcie_hide_rc_bars(bus, offset))
156 return NULL;
157
158 xgene_pcie_set_rtdid_reg(bus, devfn);
159 return xgene_pcie_get_cfg_base(bus) + offset;
160}
161
162static int xgene_pcie_config_read32(struct pci_bus *bus, unsigned int devfn,
163 int where, int size, u32 *val)
164{
165 struct xgene_pcie *port = pcie_bus_to_port(bus);
166 int ret;
167
168 ret = pci_generic_config_read32(bus, devfn, where: where & ~0x3, size: 4, val);
169 if (ret != PCIBIOS_SUCCESSFUL)
170 return ret;
171
172 /*
173 * The v1 controller has a bug in its Configuration Request Retry
174 * Status (CRS) logic: when CRS Software Visibility is enabled and
175 * we read the Vendor and Device ID of a non-existent device, the
176 * controller fabricates return data of 0xFFFF0001 ("device exists
177 * but is not ready") instead of 0xFFFFFFFF (PCI_ERROR_RESPONSE)
178 * ("device does not exist"). This causes the PCI core to retry
179 * the read until it times out. Avoid this by not claiming to
180 * support CRS SV.
181 */
182 if (pci_is_root_bus(pbus: bus) && (port->version == XGENE_PCIE_IP_VER_1) &&
183 ((where & ~0x3) == XGENE_V1_PCI_EXP_CAP + PCI_EXP_RTCTL))
184 *val &= ~(PCI_EXP_RTCAP_CRSVIS << 16);
185
186 if (size <= 2)
187 *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1);
188
189 return PCIBIOS_SUCCESSFUL;
190}
191#endif
192
193#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
194static int xgene_get_csr_resource(struct acpi_device *adev,
195 struct resource *res)
196{
197 struct device *dev = &adev->dev;
198 struct resource_entry *entry;
199 struct list_head list;
200 unsigned long flags;
201 int ret;
202
203 INIT_LIST_HEAD(list: &list);
204 flags = IORESOURCE_MEM;
205 ret = acpi_dev_get_resources(adev, list: &list,
206 preproc: acpi_dev_filter_resource_type_cb,
207 preproc_data: (void *) flags);
208 if (ret < 0) {
209 dev_err(dev, "failed to parse _CRS method, error code %d\n",
210 ret);
211 return ret;
212 }
213
214 if (ret == 0) {
215 dev_err(dev, "no IO and memory resources present in _CRS\n");
216 return -EINVAL;
217 }
218
219 entry = list_first_entry(&list, struct resource_entry, node);
220 *res = *entry->res;
221 acpi_dev_free_resource_list(list: &list);
222 return 0;
223}
224
225static int xgene_pcie_ecam_init(struct pci_config_window *cfg, u32 ipversion)
226{
227 struct device *dev = cfg->parent;
228 struct acpi_device *adev = to_acpi_device(dev);
229 struct xgene_pcie *port;
230 struct resource csr;
231 int ret;
232
233 port = devm_kzalloc(dev, size: sizeof(*port), GFP_KERNEL);
234 if (!port)
235 return -ENOMEM;
236
237 ret = xgene_get_csr_resource(adev, res: &csr);
238 if (ret) {
239 dev_err(dev, "can't get CSR resource\n");
240 return ret;
241 }
242 port->csr_base = devm_pci_remap_cfg_resource(dev, res: &csr);
243 if (IS_ERR(ptr: port->csr_base))
244 return PTR_ERR(ptr: port->csr_base);
245
246 port->cfg_base = cfg->win;
247 port->version = ipversion;
248
249 cfg->priv = port;
250 return 0;
251}
252
253static int xgene_v1_pcie_ecam_init(struct pci_config_window *cfg)
254{
255 return xgene_pcie_ecam_init(cfg, XGENE_PCIE_IP_VER_1);
256}
257
258const struct pci_ecam_ops xgene_v1_pcie_ecam_ops = {
259 .init = xgene_v1_pcie_ecam_init,
260 .pci_ops = {
261 .map_bus = xgene_pcie_map_bus,
262 .read = xgene_pcie_config_read32,
263 .write = pci_generic_config_write,
264 }
265};
266
267static int xgene_v2_pcie_ecam_init(struct pci_config_window *cfg)
268{
269 return xgene_pcie_ecam_init(cfg, XGENE_PCIE_IP_VER_2);
270}
271
272const struct pci_ecam_ops xgene_v2_pcie_ecam_ops = {
273 .init = xgene_v2_pcie_ecam_init,
274 .pci_ops = {
275 .map_bus = xgene_pcie_map_bus,
276 .read = xgene_pcie_config_read32,
277 .write = pci_generic_config_write,
278 }
279};
280#endif
281
282#if defined(CONFIG_PCI_XGENE)
283static u64 xgene_pcie_set_ib_mask(struct xgene_pcie *port, u32 addr,
284 u32 flags, u64 size)
285{
286 u64 mask = (~(size - 1) & PCI_BASE_ADDRESS_MEM_MASK) | flags;
287 u32 val32 = 0;
288 u32 val;
289
290 val32 = xgene_pcie_readl(port, reg: addr);
291 val = (val32 & 0x0000ffff) | (lower_32_bits(mask) << 16);
292 xgene_pcie_writel(port, reg: addr, val);
293
294 val32 = xgene_pcie_readl(port, reg: addr + 0x04);
295 val = (val32 & 0xffff0000) | (lower_32_bits(mask) >> 16);
296 xgene_pcie_writel(port, reg: addr + 0x04, val);
297
298 val32 = xgene_pcie_readl(port, reg: addr + 0x04);
299 val = (val32 & 0x0000ffff) | (upper_32_bits(mask) << 16);
300 xgene_pcie_writel(port, reg: addr + 0x04, val);
301
302 val32 = xgene_pcie_readl(port, reg: addr + 0x08);
303 val = (val32 & 0xffff0000) | (upper_32_bits(mask) >> 16);
304 xgene_pcie_writel(port, reg: addr + 0x08, val);
305
306 return mask;
307}
308
309static void xgene_pcie_linkup(struct xgene_pcie *port,
310 u32 *lanes, u32 *speed)
311{
312 u32 val32;
313
314 port->link_up = false;
315 val32 = xgene_pcie_readl(port, PCIECORE_CTLANDSTATUS);
316 if (val32 & LINK_UP_MASK) {
317 port->link_up = true;
318 *speed = PIPE_PHY_RATE_RD(val32);
319 val32 = xgene_pcie_readl(port, BRIDGE_STATUS_0);
320 *lanes = val32 >> 26;
321 }
322}
323
324static int xgene_pcie_init_port(struct xgene_pcie *port)
325{
326 struct device *dev = port->dev;
327 int rc;
328
329 port->clk = clk_get(dev, NULL);
330 if (IS_ERR(ptr: port->clk)) {
331 dev_err(dev, "clock not available\n");
332 return -ENODEV;
333 }
334
335 rc = clk_prepare_enable(clk: port->clk);
336 if (rc) {
337 dev_err(dev, "clock enable failed\n");
338 return rc;
339 }
340
341 return 0;
342}
343
344static int xgene_pcie_map_reg(struct xgene_pcie *port,
345 struct platform_device *pdev)
346{
347 struct device *dev = port->dev;
348 struct resource *res;
349
350 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr");
351 port->csr_base = devm_pci_remap_cfg_resource(dev, res);
352 if (IS_ERR(ptr: port->csr_base))
353 return PTR_ERR(ptr: port->csr_base);
354
355 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
356 port->cfg_base = devm_ioremap_resource(dev, res);
357 if (IS_ERR(ptr: port->cfg_base))
358 return PTR_ERR(ptr: port->cfg_base);
359 port->cfg_addr = res->start;
360
361 return 0;
362}
363
364static void xgene_pcie_setup_ob_reg(struct xgene_pcie *port,
365 struct resource *res, u32 offset,
366 u64 cpu_addr, u64 pci_addr)
367{
368 struct device *dev = port->dev;
369 resource_size_t size = resource_size(res);
370 u64 restype = resource_type(res);
371 u64 mask = 0;
372 u32 min_size;
373 u32 flag = EN_REG;
374
375 if (restype == IORESOURCE_MEM) {
376 min_size = SZ_128M;
377 } else {
378 min_size = 128;
379 flag |= OB_LO_IO;
380 }
381
382 if (size >= min_size)
383 mask = ~(size - 1) | flag;
384 else
385 dev_warn(dev, "res size 0x%llx less than minimum 0x%x\n",
386 (u64)size, min_size);
387
388 xgene_pcie_writel(port, reg: offset, lower_32_bits(cpu_addr));
389 xgene_pcie_writel(port, reg: offset + 0x04, upper_32_bits(cpu_addr));
390 xgene_pcie_writel(port, reg: offset + 0x08, lower_32_bits(mask));
391 xgene_pcie_writel(port, reg: offset + 0x0c, upper_32_bits(mask));
392 xgene_pcie_writel(port, reg: offset + 0x10, lower_32_bits(pci_addr));
393 xgene_pcie_writel(port, reg: offset + 0x14, upper_32_bits(pci_addr));
394}
395
396static void xgene_pcie_setup_cfg_reg(struct xgene_pcie *port)
397{
398 u64 addr = port->cfg_addr;
399
400 xgene_pcie_writel(port, CFGBARL, lower_32_bits(addr));
401 xgene_pcie_writel(port, CFGBARH, upper_32_bits(addr));
402 xgene_pcie_writel(port, CFGCTL, EN_REG);
403}
404
405static int xgene_pcie_map_ranges(struct xgene_pcie *port)
406{
407 struct pci_host_bridge *bridge = pci_host_bridge_from_priv(priv: port);
408 struct resource_entry *window;
409 struct device *dev = port->dev;
410
411 resource_list_for_each_entry(window, &bridge->windows) {
412 struct resource *res = window->res;
413 u64 restype = resource_type(res);
414
415 dev_dbg(dev, "%pR\n", res);
416
417 switch (restype) {
418 case IORESOURCE_IO:
419 xgene_pcie_setup_ob_reg(port, res, OMR3BARL,
420 cpu_addr: pci_pio_to_address(pio: res->start),
421 pci_addr: res->start - window->offset);
422 break;
423 case IORESOURCE_MEM:
424 if (res->flags & IORESOURCE_PREFETCH)
425 xgene_pcie_setup_ob_reg(port, res, OMR2BARL,
426 cpu_addr: res->start,
427 pci_addr: res->start -
428 window->offset);
429 else
430 xgene_pcie_setup_ob_reg(port, res, OMR1BARL,
431 cpu_addr: res->start,
432 pci_addr: res->start -
433 window->offset);
434 break;
435 case IORESOURCE_BUS:
436 break;
437 default:
438 dev_err(dev, "invalid resource %pR\n", res);
439 return -EINVAL;
440 }
441 }
442 xgene_pcie_setup_cfg_reg(port);
443 return 0;
444}
445
446static void xgene_pcie_setup_pims(struct xgene_pcie *port, u32 pim_reg,
447 u64 pim, u64 size)
448{
449 xgene_pcie_writel(port, reg: pim_reg, lower_32_bits(pim));
450 xgene_pcie_writel(port, reg: pim_reg + 0x04,
451 upper_32_bits(pim) | EN_COHERENCY);
452 xgene_pcie_writel(port, reg: pim_reg + 0x10, lower_32_bits(size));
453 xgene_pcie_writel(port, reg: pim_reg + 0x14, upper_32_bits(size));
454}
455
456/*
457 * X-Gene PCIe support maximum 3 inbound memory regions
458 * This function helps to select a region based on size of region
459 */
460static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size)
461{
462 if ((size > 4) && (size < SZ_16M) && !(*ib_reg_mask & (1 << 1))) {
463 *ib_reg_mask |= (1 << 1);
464 return 1;
465 }
466
467 if ((size > SZ_1K) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 0))) {
468 *ib_reg_mask |= (1 << 0);
469 return 0;
470 }
471
472 if ((size > SZ_1M) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 2))) {
473 *ib_reg_mask |= (1 << 2);
474 return 2;
475 }
476
477 return -EINVAL;
478}
479
480static void xgene_pcie_setup_ib_reg(struct xgene_pcie *port,
481 struct of_pci_range *range, u8 *ib_reg_mask)
482{
483 void __iomem *cfg_base = port->cfg_base;
484 struct device *dev = port->dev;
485 void __iomem *bar_addr;
486 u32 pim_reg;
487 u64 cpu_addr = range->cpu_addr;
488 u64 pci_addr = range->pci_addr;
489 u64 size = range->size;
490 u64 mask = ~(size - 1) | EN_REG;
491 u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64;
492 u32 bar_low;
493 int region;
494
495 region = xgene_pcie_select_ib_reg(ib_reg_mask, size: range->size);
496 if (region < 0) {
497 dev_warn(dev, "invalid pcie dma-range config\n");
498 return;
499 }
500
501 if (range->flags & IORESOURCE_PREFETCH)
502 flags |= PCI_BASE_ADDRESS_MEM_PREFETCH;
503
504 bar_low = pcie_bar_low_val(addr: (u32)cpu_addr, flags);
505 switch (region) {
506 case 0:
507 xgene_pcie_set_ib_mask(port, BRIDGE_CFG_4, flags, size);
508 bar_addr = cfg_base + PCI_BASE_ADDRESS_0;
509 writel(val: bar_low, addr: bar_addr);
510 writel(upper_32_bits(cpu_addr), addr: bar_addr + 0x4);
511 pim_reg = PIM1_1L;
512 break;
513 case 1:
514 xgene_pcie_writel(port, IBAR2, val: bar_low);
515 xgene_pcie_writel(port, IR2MSK, lower_32_bits(mask));
516 pim_reg = PIM2_1L;
517 break;
518 case 2:
519 xgene_pcie_writel(port, IBAR3L, val: bar_low);
520 xgene_pcie_writel(port, IBAR3L + 0x4, upper_32_bits(cpu_addr));
521 xgene_pcie_writel(port, IR3MSKL, lower_32_bits(mask));
522 xgene_pcie_writel(port, IR3MSKL + 0x4, upper_32_bits(mask));
523 pim_reg = PIM3_1L;
524 break;
525 }
526
527 xgene_pcie_setup_pims(port, pim_reg, pim: pci_addr, size: ~(size - 1));
528}
529
530static int xgene_pcie_parse_map_dma_ranges(struct xgene_pcie *port)
531{
532 struct device_node *np = port->node;
533 struct of_pci_range range;
534 struct of_pci_range_parser parser;
535 struct device *dev = port->dev;
536 u8 ib_reg_mask = 0;
537
538 if (of_pci_dma_range_parser_init(parser: &parser, node: np)) {
539 dev_err(dev, "missing dma-ranges property\n");
540 return -EINVAL;
541 }
542
543 /* Get the dma-ranges from DT */
544 for_each_of_pci_range(&parser, &range) {
545 u64 end = range.cpu_addr + range.size - 1;
546
547 dev_dbg(dev, "0x%08x 0x%016llx..0x%016llx -> 0x%016llx\n",
548 range.flags, range.cpu_addr, end, range.pci_addr);
549 xgene_pcie_setup_ib_reg(port, range: &range, ib_reg_mask: &ib_reg_mask);
550 }
551 return 0;
552}
553
554/* clear BAR configuration which was done by firmware */
555static void xgene_pcie_clear_config(struct xgene_pcie *port)
556{
557 int i;
558
559 for (i = PIM1_1L; i <= CFGCTL; i += 4)
560 xgene_pcie_writel(port, reg: i, val: 0);
561}
562
563static int xgene_pcie_setup(struct xgene_pcie *port)
564{
565 struct device *dev = port->dev;
566 u32 val, lanes = 0, speed = 0;
567 int ret;
568
569 xgene_pcie_clear_config(port);
570
571 /* setup the vendor and device IDs correctly */
572 val = (XGENE_PCIE_DEVICEID << 16) | PCI_VENDOR_ID_AMCC;
573 xgene_pcie_writel(port, BRIDGE_CFG_0, val);
574
575 ret = xgene_pcie_map_ranges(port);
576 if (ret)
577 return ret;
578
579 ret = xgene_pcie_parse_map_dma_ranges(port);
580 if (ret)
581 return ret;
582
583 xgene_pcie_linkup(port, lanes: &lanes, speed: &speed);
584 if (!port->link_up)
585 dev_info(dev, "(rc) link down\n");
586 else
587 dev_info(dev, "(rc) x%d gen-%d link up\n", lanes, speed + 1);
588 return 0;
589}
590
591static struct pci_ops xgene_pcie_ops = {
592 .map_bus = xgene_pcie_map_bus,
593 .read = xgene_pcie_config_read32,
594 .write = pci_generic_config_write32,
595};
596
597static int xgene_pcie_probe(struct platform_device *pdev)
598{
599 struct device *dev = &pdev->dev;
600 struct device_node *dn = dev->of_node;
601 struct xgene_pcie *port;
602 struct pci_host_bridge *bridge;
603 int ret;
604
605 bridge = devm_pci_alloc_host_bridge(dev, priv: sizeof(*port));
606 if (!bridge)
607 return -ENOMEM;
608
609 port = pci_host_bridge_priv(bridge);
610
611 port->node = of_node_get(node: dn);
612 port->dev = dev;
613
614 port->version = XGENE_PCIE_IP_VER_UNKN;
615 if (of_device_is_compatible(device: port->node, "apm,xgene-pcie"))
616 port->version = XGENE_PCIE_IP_VER_1;
617
618 ret = xgene_pcie_map_reg(port, pdev);
619 if (ret)
620 return ret;
621
622 ret = xgene_pcie_init_port(port);
623 if (ret)
624 return ret;
625
626 ret = xgene_pcie_setup(port);
627 if (ret)
628 return ret;
629
630 bridge->sysdata = port;
631 bridge->ops = &xgene_pcie_ops;
632
633 return pci_host_probe(bridge);
634}
635
636static const struct of_device_id xgene_pcie_match_table[] = {
637 {.compatible = "apm,xgene-pcie",},
638 {},
639};
640
641static struct platform_driver xgene_pcie_driver = {
642 .driver = {
643 .name = "xgene-pcie",
644 .of_match_table = xgene_pcie_match_table,
645 .suppress_bind_attrs = true,
646 },
647 .probe = xgene_pcie_probe,
648};
649builtin_platform_driver(xgene_pcie_driver);
650#endif
651

source code of linux/drivers/pci/controller/pci-xgene.c