1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCIe host bridge driver for Apple system-on-chips.
4 *
5 * The HW is ECAM compliant, so once the controller is initialized,
6 * the driver mostly deals MSI mapping and handling of per-port
7 * interrupts (INTx, management and error signals).
8 *
9 * Initialization requires enabling power and clocks, along with a
10 * number of register pokes.
11 *
12 * Copyright (C) 2021 Alyssa Rosenzweig <alyssa@rosenzweig.io>
13 * Copyright (C) 2021 Google LLC
14 * Copyright (C) 2021 Corellium LLC
15 * Copyright (C) 2021 Mark Kettenis <kettenis@openbsd.org>
16 *
17 * Author: Alyssa Rosenzweig <alyssa@rosenzweig.io>
18 * Author: Marc Zyngier <maz@kernel.org>
19 */
20
21#include <linux/gpio/consumer.h>
22#include <linux/kernel.h>
23#include <linux/iopoll.h>
24#include <linux/irqchip/chained_irq.h>
25#include <linux/irqdomain.h>
26#include <linux/list.h>
27#include <linux/module.h>
28#include <linux/msi.h>
29#include <linux/notifier.h>
30#include <linux/of_irq.h>
31#include <linux/pci-ecam.h>
32
33#define CORE_RC_PHYIF_CTL		0x00024
34#define   CORE_RC_PHYIF_CTL_RUN		BIT(0)
35#define CORE_RC_PHYIF_STAT		0x00028
36#define   CORE_RC_PHYIF_STAT_REFCLK	BIT(4)
37#define CORE_RC_CTL			0x00050
38#define   CORE_RC_CTL_RUN		BIT(0)
39#define CORE_RC_STAT			0x00058
40#define   CORE_RC_STAT_READY		BIT(0)
41#define CORE_FABRIC_STAT		0x04000
42#define   CORE_FABRIC_STAT_MASK		0x001F001F
43#define CORE_LANE_CFG(port)		(0x84000 + 0x4000 * (port))
44#define   CORE_LANE_CFG_REFCLK0REQ	BIT(0)
45#define   CORE_LANE_CFG_REFCLK1REQ	BIT(1)
46#define   CORE_LANE_CFG_REFCLK0ACK	BIT(2)
47#define   CORE_LANE_CFG_REFCLK1ACK	BIT(3)
48#define   CORE_LANE_CFG_REFCLKEN	(BIT(9) | BIT(10))
49#define CORE_LANE_CTL(port)		(0x84004 + 0x4000 * (port))
50#define   CORE_LANE_CTL_CFGACC		BIT(15)
51
52#define PORT_LTSSMCTL			0x00080
53#define   PORT_LTSSMCTL_START		BIT(0)
54#define PORT_INTSTAT			0x00100
55#define   PORT_INT_TUNNEL_ERR		31
56#define   PORT_INT_CPL_TIMEOUT		23
57#define   PORT_INT_RID2SID_MAPERR	22
58#define   PORT_INT_CPL_ABORT		21
59#define   PORT_INT_MSI_BAD_DATA		19
60#define   PORT_INT_MSI_ERR		18
61#define   PORT_INT_REQADDR_GT32		17
62#define   PORT_INT_AF_TIMEOUT		15
63#define   PORT_INT_LINK_DOWN		14
64#define   PORT_INT_LINK_UP		12
65#define   PORT_INT_LINK_BWMGMT		11
66#define   PORT_INT_AER_MASK		(15 << 4)
67#define   PORT_INT_PORT_ERR		4
68#define   PORT_INT_INTx(i)		i
69#define   PORT_INT_INTx_MASK		15
70#define PORT_INTMSK			0x00104
71#define PORT_INTMSKSET			0x00108
72#define PORT_INTMSKCLR			0x0010c
73#define PORT_MSICFG			0x00124
74#define   PORT_MSICFG_EN		BIT(0)
75#define   PORT_MSICFG_L2MSINUM_SHIFT	4
76#define PORT_MSIBASE			0x00128
77#define   PORT_MSIBASE_1_SHIFT		16
78#define PORT_MSIADDR			0x00168
79#define PORT_LINKSTS			0x00208
80#define   PORT_LINKSTS_UP		BIT(0)
81#define   PORT_LINKSTS_BUSY		BIT(2)
82#define PORT_LINKCMDSTS			0x00210
83#define PORT_OUTS_NPREQS		0x00284
84#define   PORT_OUTS_NPREQS_REQ		BIT(24)
85#define   PORT_OUTS_NPREQS_CPL		BIT(16)
86#define PORT_RXWR_FIFO			0x00288
87#define   PORT_RXWR_FIFO_HDR		GENMASK(15, 10)
88#define   PORT_RXWR_FIFO_DATA		GENMASK(9, 0)
89#define PORT_RXRD_FIFO			0x0028C
90#define   PORT_RXRD_FIFO_REQ		GENMASK(6, 0)
91#define PORT_OUTS_CPLS			0x00290
92#define   PORT_OUTS_CPLS_SHRD		GENMASK(14, 8)
93#define   PORT_OUTS_CPLS_WAIT		GENMASK(6, 0)
94#define PORT_APPCLK			0x00800
95#define   PORT_APPCLK_EN		BIT(0)
96#define   PORT_APPCLK_CGDIS		BIT(8)
97#define PORT_STATUS			0x00804
98#define   PORT_STATUS_READY		BIT(0)
99#define PORT_REFCLK			0x00810
100#define   PORT_REFCLK_EN		BIT(0)
101#define   PORT_REFCLK_CGDIS		BIT(8)
102#define PORT_PERST			0x00814
103#define   PORT_PERST_OFF		BIT(0)
104#define PORT_RID2SID(i16)		(0x00828 + 4 * (i16))
105#define   PORT_RID2SID_VALID		BIT(31)
106#define   PORT_RID2SID_SID_SHIFT	16
107#define   PORT_RID2SID_BUS_SHIFT	8
108#define   PORT_RID2SID_DEV_SHIFT	3
109#define   PORT_RID2SID_FUNC_SHIFT	0
110#define PORT_OUTS_PREQS_HDR		0x00980
111#define   PORT_OUTS_PREQS_HDR_MASK	GENMASK(9, 0)
112#define PORT_OUTS_PREQS_DATA		0x00984
113#define   PORT_OUTS_PREQS_DATA_MASK	GENMASK(15, 0)
114#define PORT_TUNCTRL			0x00988
115#define   PORT_TUNCTRL_PERST_ON		BIT(0)
116#define   PORT_TUNCTRL_PERST_ACK_REQ	BIT(1)
117#define PORT_TUNSTAT			0x0098c
118#define   PORT_TUNSTAT_PERST_ON		BIT(0)
119#define   PORT_TUNSTAT_PERST_ACK_PEND	BIT(1)
120#define PORT_PREFMEM_ENABLE		0x00994
121
122#define MAX_RID2SID			64
123
124/*
125 * The doorbell address is set to 0xfffff000, which by convention
126 * matches what MacOS does, and it is possible to use any other
127 * address (in the bottom 4GB, as the base register is only 32bit).
128 * However, it has to be excluded from the IOVA range, and the DART
129 * driver has to know about it.
130 */
131#define DOORBELL_ADDR		CONFIG_PCIE_APPLE_MSI_DOORBELL_ADDR
132
133struct apple_pcie {
134	struct mutex		lock;
135	struct device		*dev;
136	void __iomem            *base;
137	struct irq_domain	*domain;
138	unsigned long		*bitmap;
139	struct list_head	ports;
140	struct completion	event;
141	struct irq_fwspec	fwspec;
142	u32			nvecs;
143};
144
145struct apple_pcie_port {
146	struct apple_pcie	*pcie;
147	struct device_node	*np;
148	void __iomem		*base;
149	struct irq_domain	*domain;
150	struct list_head	entry;
151	DECLARE_BITMAP(sid_map, MAX_RID2SID);
152	int			sid_map_sz;
153	int			idx;
154};
155
156static void rmw_set(u32 set, void __iomem *addr)
157{
158	writel_relaxed(readl_relaxed(addr) | set, addr);
159}
160
161static void rmw_clear(u32 clr, void __iomem *addr)
162{
163	writel_relaxed(readl_relaxed(addr) & ~clr, addr);
164}
165
166static void apple_msi_top_irq_mask(struct irq_data *d)
167{
168	pci_msi_mask_irq(d);
169	irq_chip_mask_parent(d);
170}
171
172static void apple_msi_top_irq_unmask(struct irq_data *d)
173{
174	pci_msi_unmask_irq(d);
175	irq_chip_unmask_parent(d);
176}
177
178static struct irq_chip apple_msi_top_chip = {
179	.name			= "PCIe MSI",
180	.irq_mask		= apple_msi_top_irq_mask,
181	.irq_unmask		= apple_msi_top_irq_unmask,
182	.irq_eoi		= irq_chip_eoi_parent,
183	.irq_set_affinity	= irq_chip_set_affinity_parent,
184	.irq_set_type		= irq_chip_set_type_parent,
185};
186
187static void apple_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
188{
189	msg->address_hi = upper_32_bits(DOORBELL_ADDR);
190	msg->address_lo = lower_32_bits(DOORBELL_ADDR);
191	msg->data = data->hwirq;
192}
193
194static struct irq_chip apple_msi_bottom_chip = {
195	.name			= "MSI",
196	.irq_mask		= irq_chip_mask_parent,
197	.irq_unmask		= irq_chip_unmask_parent,
198	.irq_eoi		= irq_chip_eoi_parent,
199	.irq_set_affinity	= irq_chip_set_affinity_parent,
200	.irq_set_type		= irq_chip_set_type_parent,
201	.irq_compose_msi_msg	= apple_msi_compose_msg,
202};
203
204static int apple_msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
205				  unsigned int nr_irqs, void *args)
206{
207	struct apple_pcie *pcie = domain->host_data;
208	struct irq_fwspec fwspec = pcie->fwspec;
209	unsigned int i;
210	int ret, hwirq;
211
212	mutex_lock(&pcie->lock);
213
214	hwirq = bitmap_find_free_region(pcie->bitmap, pcie->nvecs,
215					order_base_2(nr_irqs));
216
217	mutex_unlock(&pcie->lock);
218
219	if (hwirq < 0)
220		return -ENOSPC;
221
222	fwspec.param[fwspec.param_count - 2] += hwirq;
223
224	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &fwspec);
225	if (ret)
226		return ret;
227
228	for (i = 0; i < nr_irqs; i++) {
229		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
230					      &apple_msi_bottom_chip,
231					      domain->host_data);
232	}
233
234	return 0;
235}
236
237static void apple_msi_domain_free(struct irq_domain *domain, unsigned int virq,
238				  unsigned int nr_irqs)
239{
240	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
241	struct apple_pcie *pcie = domain->host_data;
242
243	mutex_lock(&pcie->lock);
244
245	bitmap_release_region(pcie->bitmap, d->hwirq, order_base_2(nr_irqs));
246
247	mutex_unlock(&pcie->lock);
248}
249
250static const struct irq_domain_ops apple_msi_domain_ops = {
251	.alloc	= apple_msi_domain_alloc,
252	.free	= apple_msi_domain_free,
253};
254
255static struct msi_domain_info apple_msi_info = {
256	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
257		   MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX),
258	.chip	= &apple_msi_top_chip,
259};
260
261static void apple_port_irq_mask(struct irq_data *data)
262{
263	struct apple_pcie_port *port = irq_data_get_irq_chip_data(data);
264
265	writel_relaxed(BIT(data->hwirq), port->base + PORT_INTMSKSET);
266}
267
268static void apple_port_irq_unmask(struct irq_data *data)
269{
270	struct apple_pcie_port *port = irq_data_get_irq_chip_data(data);
271
272	writel_relaxed(BIT(data->hwirq), port->base + PORT_INTMSKCLR);
273}
274
275static bool hwirq_is_intx(unsigned int hwirq)
276{
277	return BIT(hwirq) & PORT_INT_INTx_MASK;
278}
279
280static void apple_port_irq_ack(struct irq_data *data)
281{
282	struct apple_pcie_port *port = irq_data_get_irq_chip_data(data);
283
284	if (!hwirq_is_intx(data->hwirq))
285		writel_relaxed(BIT(data->hwirq), port->base + PORT_INTSTAT);
286}
287
288static int apple_port_irq_set_type(struct irq_data *data, unsigned int type)
289{
290	/*
291	 * It doesn't seem that there is any way to configure the
292	 * trigger, so assume INTx have to be level (as per the spec),
293	 * and the rest is edge (which looks likely).
294	 */
295	if (hwirq_is_intx(data->hwirq) ^ !!(type & IRQ_TYPE_LEVEL_MASK))
296		return -EINVAL;
297
298	irqd_set_trigger_type(data, type);
299	return 0;
300}
301
302static struct irq_chip apple_port_irqchip = {
303	.name		= "PCIe",
304	.irq_ack	= apple_port_irq_ack,
305	.irq_mask	= apple_port_irq_mask,
306	.irq_unmask	= apple_port_irq_unmask,
307	.irq_set_type	= apple_port_irq_set_type,
308};
309
310static int apple_port_irq_domain_alloc(struct irq_domain *domain,
311				       unsigned int virq, unsigned int nr_irqs,
312				       void *args)
313{
314	struct apple_pcie_port *port = domain->host_data;
315	struct irq_fwspec *fwspec = args;
316	int i;
317
318	for (i = 0; i < nr_irqs; i++) {
319		irq_flow_handler_t flow = handle_edge_irq;
320		unsigned int type = IRQ_TYPE_EDGE_RISING;
321
322		if (hwirq_is_intx(fwspec->param[0] + i)) {
323			flow = handle_level_irq;
324			type = IRQ_TYPE_LEVEL_HIGH;
325		}
326
327		irq_domain_set_info(domain, virq + i, fwspec->param[0] + i,
328				    &apple_port_irqchip, port, flow,
329				    NULL, NULL);
330
331		irq_set_irq_type(virq + i, type);
332	}
333
334	return 0;
335}
336
337static void apple_port_irq_domain_free(struct irq_domain *domain,
338				       unsigned int virq, unsigned int nr_irqs)
339{
340	int i;
341
342	for (i = 0; i < nr_irqs; i++) {
343		struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
344
345		irq_set_handler(virq + i, NULL);
346		irq_domain_reset_irq_data(d);
347	}
348}
349
350static const struct irq_domain_ops apple_port_irq_domain_ops = {
351	.translate	= irq_domain_translate_onecell,
352	.alloc		= apple_port_irq_domain_alloc,
353	.free		= apple_port_irq_domain_free,
354};
355
356static void apple_port_irq_handler(struct irq_desc *desc)
357{
358	struct apple_pcie_port *port = irq_desc_get_handler_data(desc);
359	struct irq_chip *chip = irq_desc_get_chip(desc);
360	unsigned long stat;
361	int i;
362
363	chained_irq_enter(chip, desc);
364
365	stat = readl_relaxed(port->base + PORT_INTSTAT);
366
367	for_each_set_bit(i, &stat, 32)
368		generic_handle_domain_irq(port->domain, i);
369
370	chained_irq_exit(chip, desc);
371}
372
373static int apple_pcie_port_setup_irq(struct apple_pcie_port *port)
374{
375	struct fwnode_handle *fwnode = &port->np->fwnode;
376	unsigned int irq;
377
378	/* FIXME: consider moving each interrupt under each port */
379	irq = irq_of_parse_and_map(to_of_node(dev_fwnode(port->pcie->dev)),
380				   port->idx);
381	if (!irq)
382		return -ENXIO;
383
384	port->domain = irq_domain_create_linear(fwnode, 32,
385						&apple_port_irq_domain_ops,
386						port);
387	if (!port->domain)
388		return -ENOMEM;
389
390	/* Disable all interrupts */
391	writel_relaxed(~0, port->base + PORT_INTMSKSET);
392	writel_relaxed(~0, port->base + PORT_INTSTAT);
393
394	irq_set_chained_handler_and_data(irq, apple_port_irq_handler, port);
395
396	/* Configure MSI base address */
397	BUILD_BUG_ON(upper_32_bits(DOORBELL_ADDR));
398	writel_relaxed(lower_32_bits(DOORBELL_ADDR), port->base + PORT_MSIADDR);
399
400	/* Enable MSIs, shared between all ports */
401	writel_relaxed(0, port->base + PORT_MSIBASE);
402	writel_relaxed((ilog2(port->pcie->nvecs) << PORT_MSICFG_L2MSINUM_SHIFT) |
403		       PORT_MSICFG_EN, port->base + PORT_MSICFG);
404
405	return 0;
406}
407
408static irqreturn_t apple_pcie_port_irq(int irq, void *data)
409{
410	struct apple_pcie_port *port = data;
411	unsigned int hwirq = irq_domain_get_irq_data(port->domain, irq)->hwirq;
412
413	switch (hwirq) {
414	case PORT_INT_LINK_UP:
415		dev_info_ratelimited(port->pcie->dev, "Link up on %pOF\n",
416				     port->np);
417		complete_all(&port->pcie->event);
418		break;
419	case PORT_INT_LINK_DOWN:
420		dev_info_ratelimited(port->pcie->dev, "Link down on %pOF\n",
421				     port->np);
422		break;
423	default:
424		return IRQ_NONE;
425	}
426
427	return IRQ_HANDLED;
428}
429
430static int apple_pcie_port_register_irqs(struct apple_pcie_port *port)
431{
432	static struct {
433		unsigned int	hwirq;
434		const char	*name;
435	} port_irqs[] = {
436		{ PORT_INT_LINK_UP,	"Link up",	},
437		{ PORT_INT_LINK_DOWN,	"Link down",	},
438	};
439	int i;
440
441	for (i = 0; i < ARRAY_SIZE(port_irqs); i++) {
442		struct irq_fwspec fwspec = {
443			.fwnode		= &port->np->fwnode,
444			.param_count	= 1,
445			.param		= {
446				[0]	= port_irqs[i].hwirq,
447			},
448		};
449		unsigned int irq;
450		int ret;
451
452		irq = irq_domain_alloc_irqs(port->domain, 1, NUMA_NO_NODE,
453					    &fwspec);
454		if (WARN_ON(!irq))
455			continue;
456
457		ret = request_irq(irq, apple_pcie_port_irq, 0,
458				  port_irqs[i].name, port);
459		WARN_ON(ret);
460	}
461
462	return 0;
463}
464
465static int apple_pcie_setup_refclk(struct apple_pcie *pcie,
466				   struct apple_pcie_port *port)
467{
468	u32 stat;
469	int res;
470
471	res = readl_relaxed_poll_timeout(pcie->base + CORE_RC_PHYIF_STAT, stat,
472					 stat & CORE_RC_PHYIF_STAT_REFCLK,
473					 100, 50000);
474	if (res < 0)
475		return res;
476
477	rmw_set(CORE_LANE_CTL_CFGACC, pcie->base + CORE_LANE_CTL(port->idx));
478	rmw_set(CORE_LANE_CFG_REFCLK0REQ, pcie->base + CORE_LANE_CFG(port->idx));
479
480	res = readl_relaxed_poll_timeout(pcie->base + CORE_LANE_CFG(port->idx),
481					 stat, stat & CORE_LANE_CFG_REFCLK0ACK,
482					 100, 50000);
483	if (res < 0)
484		return res;
485
486	rmw_set(CORE_LANE_CFG_REFCLK1REQ, pcie->base + CORE_LANE_CFG(port->idx));
487	res = readl_relaxed_poll_timeout(pcie->base + CORE_LANE_CFG(port->idx),
488					 stat, stat & CORE_LANE_CFG_REFCLK1ACK,
489					 100, 50000);
490
491	if (res < 0)
492		return res;
493
494	rmw_clear(CORE_LANE_CTL_CFGACC, pcie->base + CORE_LANE_CTL(port->idx));
495
496	rmw_set(CORE_LANE_CFG_REFCLKEN, pcie->base + CORE_LANE_CFG(port->idx));
497	rmw_set(PORT_REFCLK_EN, port->base + PORT_REFCLK);
498
499	return 0;
500}
501
502static u32 apple_pcie_rid2sid_write(struct apple_pcie_port *port,
503				    int idx, u32 val)
504{
505	writel_relaxed(val, port->base + PORT_RID2SID(idx));
506	/* Read back to ensure completion of the write */
507	return readl_relaxed(port->base + PORT_RID2SID(idx));
508}
509
510static int apple_pcie_setup_port(struct apple_pcie *pcie,
511				 struct device_node *np)
512{
513	struct platform_device *platform = to_platform_device(pcie->dev);
514	struct apple_pcie_port *port;
515	struct gpio_desc *reset;
516	u32 stat, idx;
517	int ret, i;
518
519	reset = devm_fwnode_gpiod_get(pcie->dev, of_fwnode_handle(np), "reset",
520				      GPIOD_OUT_LOW, "PERST#");
521	if (IS_ERR(reset))
522		return PTR_ERR(reset);
523
524	port = devm_kzalloc(pcie->dev, sizeof(*port), GFP_KERNEL);
525	if (!port)
526		return -ENOMEM;
527
528	ret = of_property_read_u32_index(np, "reg", 0, &idx);
529	if (ret)
530		return ret;
531
532	/* Use the first reg entry to work out the port index */
533	port->idx = idx >> 11;
534	port->pcie = pcie;
535	port->np = np;
536
537	port->base = devm_platform_ioremap_resource(platform, port->idx + 2);
538	if (IS_ERR(port->base))
539		return PTR_ERR(port->base);
540
541	rmw_set(PORT_APPCLK_EN, port->base + PORT_APPCLK);
542
543	/* Assert PERST# before setting up the clock */
544	gpiod_set_value(reset, 1);
545
546	ret = apple_pcie_setup_refclk(pcie, port);
547	if (ret < 0)
548		return ret;
549
550	/* The minimal Tperst-clk value is 100us (PCIe CEM r5.0, 2.9.2) */
551	usleep_range(100, 200);
552
553	/* Deassert PERST# */
554	rmw_set(PORT_PERST_OFF, port->base + PORT_PERST);
555	gpiod_set_value(reset, 0);
556
557	/* Wait for 100ms after PERST# deassertion (PCIe r5.0, 6.6.1) */
558	msleep(100);
559
560	ret = readl_relaxed_poll_timeout(port->base + PORT_STATUS, stat,
561					 stat & PORT_STATUS_READY, 100, 250000);
562	if (ret < 0) {
563		dev_err(pcie->dev, "port %pOF ready wait timeout\n", np);
564		return ret;
565	}
566
567	rmw_clear(PORT_REFCLK_CGDIS, port->base + PORT_REFCLK);
568	rmw_clear(PORT_APPCLK_CGDIS, port->base + PORT_APPCLK);
569
570	ret = apple_pcie_port_setup_irq(port);
571	if (ret)
572		return ret;
573
574	/* Reset all RID/SID mappings, and check for RAZ/WI registers */
575	for (i = 0; i < MAX_RID2SID; i++) {
576		if (apple_pcie_rid2sid_write(port, i, 0xbad1d) != 0xbad1d)
577			break;
578		apple_pcie_rid2sid_write(port, i, 0);
579	}
580
581	dev_dbg(pcie->dev, "%pOF: %d RID/SID mapping entries\n", np, i);
582
583	port->sid_map_sz = i;
584
585	list_add_tail(&port->entry, &pcie->ports);
586	init_completion(&pcie->event);
587
588	ret = apple_pcie_port_register_irqs(port);
589	WARN_ON(ret);
590
591	writel_relaxed(PORT_LTSSMCTL_START, port->base + PORT_LTSSMCTL);
592
593	if (!wait_for_completion_timeout(&pcie->event, HZ / 10))
594		dev_warn(pcie->dev, "%pOF link didn't come up\n", np);
595
596	return 0;
597}
598
599static int apple_msi_init(struct apple_pcie *pcie)
600{
601	struct fwnode_handle *fwnode = dev_fwnode(pcie->dev);
602	struct of_phandle_args args = {};
603	struct irq_domain *parent;
604	int ret;
605
606	ret = of_parse_phandle_with_args(to_of_node(fwnode), "msi-ranges",
607					 "#interrupt-cells", 0, &args);
608	if (ret)
609		return ret;
610
611	ret = of_property_read_u32_index(to_of_node(fwnode), "msi-ranges",
612					 args.args_count + 1, &pcie->nvecs);
613	if (ret)
614		return ret;
615
616	of_phandle_args_to_fwspec(args.np, args.args, args.args_count,
617				  &pcie->fwspec);
618
619	pcie->bitmap = devm_bitmap_zalloc(pcie->dev, pcie->nvecs, GFP_KERNEL);
620	if (!pcie->bitmap)
621		return -ENOMEM;
622
623	parent = irq_find_matching_fwspec(&pcie->fwspec, DOMAIN_BUS_WIRED);
624	if (!parent) {
625		dev_err(pcie->dev, "failed to find parent domain\n");
626		return -ENXIO;
627	}
628
629	parent = irq_domain_create_hierarchy(parent, 0, pcie->nvecs, fwnode,
630					     &apple_msi_domain_ops, pcie);
631	if (!parent) {
632		dev_err(pcie->dev, "failed to create IRQ domain\n");
633		return -ENOMEM;
634	}
635	irq_domain_update_bus_token(parent, DOMAIN_BUS_NEXUS);
636
637	pcie->domain = pci_msi_create_irq_domain(fwnode, &apple_msi_info,
638						 parent);
639	if (!pcie->domain) {
640		dev_err(pcie->dev, "failed to create MSI domain\n");
641		irq_domain_remove(parent);
642		return -ENOMEM;
643	}
644
645	return 0;
646}
647
648static struct apple_pcie_port *apple_pcie_get_port(struct pci_dev *pdev)
649{
650	struct pci_config_window *cfg = pdev->sysdata;
651	struct apple_pcie *pcie = cfg->priv;
652	struct pci_dev *port_pdev;
653	struct apple_pcie_port *port;
654
655	/* Find the root port this device is on */
656	port_pdev = pcie_find_root_port(pdev);
657
658	/* If finding the port itself, nothing to do */
659	if (WARN_ON(!port_pdev) || pdev == port_pdev)
660		return NULL;
661
662	list_for_each_entry(port, &pcie->ports, entry) {
663		if (port->idx == PCI_SLOT(port_pdev->devfn))
664			return port;
665	}
666
667	return NULL;
668}
669
670static int apple_pcie_add_device(struct apple_pcie_port *port,
671				 struct pci_dev *pdev)
672{
673	u32 sid, rid = pci_dev_id(pdev);
674	int idx, err;
675
676	dev_dbg(&pdev->dev, "added to bus %s, index %d\n",
677		pci_name(pdev->bus->self), port->idx);
678
679	err = of_map_id(port->pcie->dev->of_node, rid, "iommu-map",
680			"iommu-map-mask", NULL, &sid);
681	if (err)
682		return err;
683
684	mutex_lock(&port->pcie->lock);
685
686	idx = bitmap_find_free_region(port->sid_map, port->sid_map_sz, 0);
687	if (idx >= 0) {
688		apple_pcie_rid2sid_write(port, idx,
689					 PORT_RID2SID_VALID |
690					 (sid << PORT_RID2SID_SID_SHIFT) | rid);
691
692		dev_dbg(&pdev->dev, "mapping RID%x to SID%x (index %d)\n",
693			rid, sid, idx);
694	}
695
696	mutex_unlock(&port->pcie->lock);
697
698	return idx >= 0 ? 0 : -ENOSPC;
699}
700
701static void apple_pcie_release_device(struct apple_pcie_port *port,
702				      struct pci_dev *pdev)
703{
704	u32 rid = pci_dev_id(pdev);
705	int idx;
706
707	mutex_lock(&port->pcie->lock);
708
709	for_each_set_bit(idx, port->sid_map, port->sid_map_sz) {
710		u32 val;
711
712		val = readl_relaxed(port->base + PORT_RID2SID(idx));
713		if ((val & 0xffff) == rid) {
714			apple_pcie_rid2sid_write(port, idx, 0);
715			bitmap_release_region(port->sid_map, idx, 0);
716			dev_dbg(&pdev->dev, "Released %x (%d)\n", val, idx);
717			break;
718		}
719	}
720
721	mutex_unlock(&port->pcie->lock);
722}
723
724static int apple_pcie_bus_notifier(struct notifier_block *nb,
725				   unsigned long action,
726				   void *data)
727{
728	struct device *dev = data;
729	struct pci_dev *pdev = to_pci_dev(dev);
730	struct apple_pcie_port *port;
731	int err;
732
733	/*
734	 * This is a bit ugly. We assume that if we get notified for
735	 * any PCI device, we must be in charge of it, and that there
736	 * is no other PCI controller in the whole system. It probably
737	 * holds for now, but who knows for how long?
738	 */
739	port = apple_pcie_get_port(pdev);
740	if (!port)
741		return NOTIFY_DONE;
742
743	switch (action) {
744	case BUS_NOTIFY_ADD_DEVICE:
745		err = apple_pcie_add_device(port, pdev);
746		if (err)
747			return notifier_from_errno(err);
748		break;
749	case BUS_NOTIFY_DEL_DEVICE:
750		apple_pcie_release_device(port, pdev);
751		break;
752	default:
753		return NOTIFY_DONE;
754	}
755
756	return NOTIFY_OK;
757}
758
759static struct notifier_block apple_pcie_nb = {
760	.notifier_call = apple_pcie_bus_notifier,
761};
762
763static int apple_pcie_init(struct pci_config_window *cfg)
764{
765	struct device *dev = cfg->parent;
766	struct platform_device *platform = to_platform_device(dev);
767	struct device_node *of_port;
768	struct apple_pcie *pcie;
769	int ret;
770
771	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
772	if (!pcie)
773		return -ENOMEM;
774
775	pcie->dev = dev;
776
777	mutex_init(&pcie->lock);
778
779	pcie->base = devm_platform_ioremap_resource(platform, 1);
780	if (IS_ERR(pcie->base))
781		return PTR_ERR(pcie->base);
782
783	cfg->priv = pcie;
784	INIT_LIST_HEAD(&pcie->ports);
785
786	ret = apple_msi_init(pcie);
787	if (ret)
788		return ret;
789
790	for_each_child_of_node(dev->of_node, of_port) {
791		ret = apple_pcie_setup_port(pcie, of_port);
792		if (ret) {
793			dev_err(pcie->dev, "Port %pOF setup fail: %d\n", of_port, ret);
794			of_node_put(of_port);
795			return ret;
796		}
797	}
798
799	return 0;
800}
801
802static int apple_pcie_probe(struct platform_device *pdev)
803{
804	int ret;
805
806	ret = bus_register_notifier(&pci_bus_type, &apple_pcie_nb);
807	if (ret)
808		return ret;
809
810	ret = pci_host_common_probe(pdev);
811	if (ret)
812		bus_unregister_notifier(&pci_bus_type, &apple_pcie_nb);
813
814	return ret;
815}
816
817static const struct pci_ecam_ops apple_pcie_cfg_ecam_ops = {
818	.init		= apple_pcie_init,
819	.pci_ops	= {
820		.map_bus	= pci_ecam_map_bus,
821		.read		= pci_generic_config_read,
822		.write		= pci_generic_config_write,
823	}
824};
825
826static const struct of_device_id apple_pcie_of_match[] = {
827	{ .compatible = "apple,pcie", .data = &apple_pcie_cfg_ecam_ops },
828	{ }
829};
830MODULE_DEVICE_TABLE(of, apple_pcie_of_match);
831
832static struct platform_driver apple_pcie_driver = {
833	.probe	= apple_pcie_probe,
834	.driver	= {
835		.name			= "pcie-apple",
836		.of_match_table		= apple_pcie_of_match,
837		.suppress_bind_attrs	= true,
838	},
839};
840module_platform_driver(apple_pcie_driver);
841
842MODULE_LICENSE("GPL v2");
843