aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/brcm2708/patches-4.19/950-0532-PCI-brcmstb-Add-MSI-capability.patch
blob: 63985cab8b284850474707eb411015d821d304e0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
From 2f802e11ea7ca4f7c688ecc64019bec25a5e62a1 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Tue, 19 Feb 2019 22:06:59 +0000
Subject: [PATCH 532/725] PCI: brcmstb: Add MSI capability

This commit adds MSI to the Broadcom STB PCIe host controller. It does
not add MSIX since that functionality is not in the HW.  The MSI
controller is physically located within the PCIe block, however, there
is no reason why the MSI controller could not be moved elsewhere in
the future.

Since the internal Brcmstb MSI controller is intertwined with the PCIe
controller, it is not its own platform device but rather part of the
PCIe platform device.

Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
---
 drivers/pci/controller/pcie-brcmstb.c | 374 ++++++++++++++++++++++++--
 1 file changed, 353 insertions(+), 21 deletions(-)

--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (C) 2009 - 2017 Broadcom */
 
+#include <linux/bitops.h>
 #include <linux/clk.h>
 #include <linux/compiler.h>
 #include <linux/delay.h>
@@ -9,11 +10,13 @@
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/ioport.h>
+#include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/log2.h>
 #include <linux/module.h>
+#include <linux/msi.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_pci.h>
@@ -47,6 +50,9 @@
 #define PCIE_MISC_RC_BAR2_CONFIG_LO			0x4034
 #define PCIE_MISC_RC_BAR2_CONFIG_HI			0x4038
 #define PCIE_MISC_RC_BAR3_CONFIG_LO			0x403c
+#define PCIE_MISC_MSI_BAR_CONFIG_LO			0x4044
+#define PCIE_MISC_MSI_BAR_CONFIG_HI			0x4048
+#define PCIE_MISC_MSI_DATA_CONFIG			0x404c
 #define PCIE_MISC_PCIE_CTRL				0x4064
 #define PCIE_MISC_PCIE_STATUS				0x4068
 #define PCIE_MISC_REVISION				0x406c
@@ -55,6 +61,7 @@
 #define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI		0x4084
 #define PCIE_MISC_HARD_PCIE_HARD_DEBUG			0x4204
 #define PCIE_INTR2_CPU_BASE				0x4300
+#define PCIE_MSI_INTR2_BASE				0x4500
 
 /*
  * Broadcom Settop Box PCIe Register Field shift and mask info. The
@@ -115,6 +122,8 @@
 
 #define BRCM_NUM_PCIE_OUT_WINS		0x4
 #define BRCM_MAX_SCB			0x4
+#define BRCM_INT_PCI_MSI_NR		32
+#define BRCM_PCIE_HW_REV_33		0x0303
 
 #define BRCM_MSI_TARGET_ADDR_LT_4GB	0x0fffffffcULL
 #define BRCM_MSI_TARGET_ADDR_GT_4GB	0xffffffffcULL
@@ -203,6 +212,33 @@ struct brcm_window {
 	dma_addr_t size;
 };
 
+struct brcm_msi {
+	struct device		*dev;
+	void __iomem		*base;
+	struct device_node	*dn;
+	struct irq_domain	*msi_domain;
+	struct irq_domain	*inner_domain;
+	struct mutex		lock; /* guards the alloc/free operations */
+	u64			target_addr;
+	int			irq;
+
+	/* intr_base is the base pointer for interrupt status/set/clr regs */
+	void __iomem		*intr_base;
+
+	/* intr_legacy_mask indicates how many bits are MSI interrupts */
+	u32			intr_legacy_mask;
+
+	/*
+	 * intr_legacy_offset indicates bit position of MSI_01. It is
+	 * to map the register bit position to a hwirq that starts at 0.
+	 */
+	u32			intr_legacy_offset;
+
+	/* used indicates which MSI interrupts have been alloc'd */
+	unsigned long		used;
+	unsigned int		rev;
+};
+
 /* Internal PCIe Host Controller Information.*/
 struct brcm_pcie {
 	struct device		*dev;
@@ -217,7 +253,10 @@ struct brcm_pcie {
 	int			num_out_wins;
 	bool			ssc;
 	int			gen;
+	u64			msi_target_addr;
 	struct brcm_window	out_wins[BRCM_NUM_PCIE_OUT_WINS];
+	struct brcm_msi		*msi;
+	bool			msi_internal;
 	unsigned int		rev;
 	const int		*reg_offsets;
 	const int		*reg_field_info;
@@ -225,9 +264,9 @@ struct brcm_pcie {
 };
 
 struct pcie_cfg_data {
-	const int *reg_field_info;
-	const int *offsets;
-	const enum pcie_type type;
+	const int		*reg_field_info;
+	const int		*offsets;
+	const enum pcie_type	type;
 };
 
 static const int pcie_reg_field_info[] = {
@@ -828,6 +867,267 @@ static void brcm_pcie_set_outbound_win(s
 	}
 }
 
+static struct irq_chip brcm_msi_irq_chip = {
+	.name = "Brcm_MSI",
+	.irq_mask = pci_msi_mask_irq,
+	.irq_unmask = pci_msi_unmask_irq,
+};
+
+static struct msi_domain_info brcm_msi_domain_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+		   MSI_FLAG_PCI_MSIX),
+	.chip	= &brcm_msi_irq_chip,
+};
+
+static void brcm_pcie_msi_isr(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct brcm_msi *msi;
+	unsigned long status, virq;
+	u32 mask, bit, hwirq;
+	struct device *dev;
+
+	chained_irq_enter(chip, desc);
+	msi = irq_desc_get_handler_data(desc);
+	mask = msi->intr_legacy_mask;
+	dev = msi->dev;
+
+	while ((status = bcm_readl(msi->intr_base + STATUS) & mask)) {
+		for_each_set_bit(bit, &status, BRCM_INT_PCI_MSI_NR) {
+			/* clear the interrupt */
+			bcm_writel(1 << bit, msi->intr_base + CLR);
+
+			/* Account for legacy interrupt offset */
+			hwirq = bit - msi->intr_legacy_offset;
+
+			virq = irq_find_mapping(msi->inner_domain, hwirq);
+			if (virq) {
+				if (msi->used & (1 << hwirq))
+					generic_handle_irq(virq);
+				else
+					dev_info(dev, "unhandled MSI %d\n",
+						 hwirq);
+			} else {
+				/* Unknown MSI, just clear it */
+				dev_dbg(dev, "unexpected MSI\n");
+			}
+		}
+	}
+	chained_irq_exit(chip, desc);
+}
+
+static void brcm_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	struct brcm_msi *msi = irq_data_get_irq_chip_data(data);
+	u32 temp;
+
+	msg->address_lo = lower_32_bits(msi->target_addr);
+	msg->address_hi = upper_32_bits(msi->target_addr);
+	temp = bcm_readl(msi->base + PCIE_MISC_MSI_DATA_CONFIG);
+	msg->data = ((temp >> 16) & (temp & 0xffff)) | data->hwirq;
+}
+
+static int brcm_msi_set_affinity(struct irq_data *irq_data,
+				 const struct cpumask *mask, bool force)
+{
+	return -EINVAL;
+}
+
+static struct irq_chip brcm_msi_bottom_irq_chip = {
+	.name			= "Brcm_MSI",
+	.irq_compose_msi_msg	= brcm_compose_msi_msg,
+	.irq_set_affinity	= brcm_msi_set_affinity,
+};
+
+static int brcm_msi_alloc(struct brcm_msi *msi)
+{
+	int bit, hwirq;
+
+	mutex_lock(&msi->lock);
+	bit = ~msi->used ? ffz(msi->used) : -1;
+
+	if (bit >= 0 && bit < BRCM_INT_PCI_MSI_NR) {
+		msi->used |= (1 << bit);
+		hwirq = bit - msi->intr_legacy_offset;
+	} else {
+		hwirq = -ENOSPC;
+	}
+
+	mutex_unlock(&msi->lock);
+	return hwirq;
+}
+
+static void brcm_msi_free(struct brcm_msi *msi, unsigned long hwirq)
+{
+	mutex_lock(&msi->lock);
+	msi->used &= ~(1 << (hwirq + msi->intr_legacy_offset));
+	mutex_unlock(&msi->lock);
+}
+
+static int brcm_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				 unsigned int nr_irqs, void *args)
+{
+	struct brcm_msi *msi = domain->host_data;
+	int hwirq;
+
+	hwirq = brcm_msi_alloc(msi);
+
+	if (hwirq < 0)
+		return hwirq;
+
+	irq_domain_set_info(domain, virq, (irq_hw_number_t)hwirq,
+			    &brcm_msi_bottom_irq_chip, domain->host_data,
+			    handle_simple_irq, NULL, NULL);
+	return 0;
+}
+
+static void brcm_irq_domain_free(struct irq_domain *domain,
+				 unsigned int virq, unsigned int nr_irqs)
+{
+	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+	struct brcm_msi *msi = irq_data_get_irq_chip_data(d);
+
+	brcm_msi_free(msi, d->hwirq);
+}
+
+static void brcm_msi_set_regs(struct brcm_msi *msi)
+{
+	u32 data_val, msi_lo, msi_hi;
+
+	if (msi->rev >= BRCM_PCIE_HW_REV_33) {
+		/*
+		 * ffe0 -- least sig 5 bits are 0 indicating 32 msgs
+		 * 6540 -- this is our arbitrary unique data value
+		 */
+		data_val = 0xffe06540;
+	} else {
+		/*
+		 * fff8 -- least sig 3 bits are 0 indicating 8 msgs
+		 * 6540 -- this is our arbitrary unique data value
+		 */
+		data_val = 0xfff86540;
+	}
+
+	/*
+	 * Make sure we are not masking MSIs.  Note that MSIs can be masked,
+	 * but that occurs on the PCIe EP device
+	 */
+	bcm_writel(0xffffffff & msi->intr_legacy_mask,
+		   msi->intr_base + MASK_CLR);
+
+	msi_lo = lower_32_bits(msi->target_addr);
+	msi_hi = upper_32_bits(msi->target_addr);
+	/*
+	 * The 0 bit of PCIE_MISC_MSI_BAR_CONFIG_LO is repurposed to MSI
+	 * enable, which we set to 1.
+	 */
+	bcm_writel(msi_lo | 1, msi->base + PCIE_MISC_MSI_BAR_CONFIG_LO);
+	bcm_writel(msi_hi, msi->base + PCIE_MISC_MSI_BAR_CONFIG_HI);
+	bcm_writel(data_val, msi->base + PCIE_MISC_MSI_DATA_CONFIG);
+}
+
+static const struct irq_domain_ops msi_domain_ops = {
+	.alloc	= brcm_irq_domain_alloc,
+	.free	= brcm_irq_domain_free,
+};
+
+static int brcm_allocate_domains(struct brcm_msi *msi)
+{
+	struct fwnode_handle *fwnode = of_node_to_fwnode(msi->dn);
+	struct device *dev = msi->dev;
+
+	msi->inner_domain = irq_domain_add_linear(NULL, BRCM_INT_PCI_MSI_NR,
+						  &msi_domain_ops, msi);
+	if (!msi->inner_domain) {
+		dev_err(dev, "failed to create IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	msi->msi_domain = pci_msi_create_irq_domain(fwnode,
+						    &brcm_msi_domain_info,
+						    msi->inner_domain);
+	if (!msi->msi_domain) {
+		dev_err(dev, "failed to create MSI domain\n");
+		irq_domain_remove(msi->inner_domain);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void brcm_free_domains(struct brcm_msi *msi)
+{
+	irq_domain_remove(msi->msi_domain);
+	irq_domain_remove(msi->inner_domain);
+}
+
+static void brcm_msi_remove(struct brcm_pcie *pcie)
+{
+	struct brcm_msi *msi = pcie->msi;
+
+	if (!msi)
+		return;
+	irq_set_chained_handler(msi->irq, NULL);
+	irq_set_handler_data(msi->irq, NULL);
+	brcm_free_domains(msi);
+}
+
+static int brcm_pcie_enable_msi(struct brcm_pcie *pcie)
+{
+	struct brcm_msi *msi;
+	int irq, ret;
+	struct device *dev = pcie->dev;
+
+	irq = irq_of_parse_and_map(dev->of_node, 1);
+	if (irq <= 0) {
+		dev_err(dev, "cannot map msi intr\n");
+		return -ENODEV;
+	}
+
+	msi = devm_kzalloc(dev, sizeof(struct brcm_msi), GFP_KERNEL);
+	if (!msi)
+		return -ENOMEM;
+
+	msi->dev = dev;
+	msi->base = pcie->base;
+	msi->rev =  pcie->rev;
+	msi->dn = pcie->dn;
+	msi->target_addr = pcie->msi_target_addr;
+	msi->irq = irq;
+
+	ret = brcm_allocate_domains(msi);
+	if (ret)
+		return ret;
+
+	irq_set_chained_handler_and_data(msi->irq, brcm_pcie_msi_isr, msi);
+
+	if (msi->rev >= BRCM_PCIE_HW_REV_33) {
+		msi->intr_base = msi->base + PCIE_MSI_INTR2_BASE;
+		/*
+		 * This version of PCIe hw has only 32 intr bits
+		 * starting at bit position 0.
+		 */
+		msi->intr_legacy_mask = 0xffffffff;
+		msi->intr_legacy_offset = 0x0;
+		msi->used = 0x0;
+
+	} else {
+		msi->intr_base = msi->base + PCIE_INTR2_CPU_BASE;
+		/*
+		 * This version of PCIe hw has only 8 intr bits starting
+		 * at bit position 24.
+		 */
+		msi->intr_legacy_mask = 0xff000000;
+		msi->intr_legacy_offset = 24;
+		msi->used = 0x00ffffff;
+	}
+
+	brcm_msi_set_regs(msi);
+	pcie->msi = msi;
+
+	return 0;
+}
+
 /* Configuration space read/write support */
 static int cfg_index(int busnr, int devfn, int reg)
 {
@@ -1072,6 +1372,7 @@ static int brcm_pcie_setup(struct brcm_p
 	u16 nlw, cls, lnksta;
 	bool ssc_good = false;
 	struct device *dev = pcie->dev;
+	u64 msi_target_addr;
 
 	/* Reset the bridge */
 	brcm_pcie_bridge_sw_init_set(pcie, 1);
@@ -1116,27 +1417,24 @@ static int brcm_pcie_setup(struct brcm_p
 	 * The PCIe host controller by design must set the inbound
 	 * viewport to be a contiguous arrangement of all of the
 	 * system's memory.  In addition, its size mut be a power of
-	 * two.  To further complicate matters, the viewport must
-	 * start on a pcie-address that is aligned on a multiple of its
-	 * size.  If a portion of the viewport does not represent
-	 * system memory -- e.g. 3GB of memory requires a 4GB viewport
-	 * -- we can map the outbound memory in or after 3GB and even
-	 * though the viewport will overlap the outbound memory the
-	 * controller will know to send outbound memory downstream and
-	 * everything else upstream.
+	 * two.  Further, the MSI target address must NOT be placed
+	 * inside this region, as the decoding logic will consider its
+	 * address to be inbound memory traffic.  To further
+	 * complicate matters, the viewport must start on a
+	 * pcie-address that is aligned on a multiple of its size.
+	 * If a portion of the viewport does not represent system
+	 * memory -- e.g. 3GB of memory requires a 4GB viewport --
+	 * we can map the outbound memory in or after 3GB and even
+	 * though the viewport will overlap the outbound memory
+	 * the controller will know to send outbound memory downstream
+	 * and everything else upstream.
 	 */
 	rc_bar2_size = roundup_pow_of_two_64(total_mem_size);
 
-	/*
-	 * Set simple configuration based on memory sizes
-	 * only.  We always start the viewport at address 0.
-	 */
-	rc_bar2_offset = 0;
-
 	if (dma_ranges) {
 		/*
 		 * The best-case scenario is to place the inbound
-		 * region in the first 4GB of pci-space, as some
+		 * region in the first 4GB of pcie-space, as some
 		 * legacy devices can only address 32bits.
 		 * We would also like to put the MSI under 4GB
 		 * as well, since some devices require a 32bit
@@ -1145,6 +1443,14 @@ static int brcm_pcie_setup(struct brcm_p
 		if (total_mem_size <= 0xc0000000ULL &&
 		    rc_bar2_size <= 0x100000000ULL) {
 			rc_bar2_offset = 0;
+			/* If the viewport is less then 4GB we can fit
+			 * the MSI target address under 4GB. Otherwise
+			 * put it right below 64GB.
+			 */
+			msi_target_addr =
+				(rc_bar2_size == 0x100000000ULL)
+				? BRCM_MSI_TARGET_ADDR_GT_4GB
+				: BRCM_MSI_TARGET_ADDR_LT_4GB;
 		} else {
 			/*
 			 * The system memory is 4GB or larger so we
@@ -1154,8 +1460,12 @@ static int brcm_pcie_setup(struct brcm_p
 			 * start it at the 1x multiple of its size
 			 */
 			rc_bar2_offset = rc_bar2_size;
-		}
 
+			/* Since we are starting the viewport at 4GB or
+			 * higher, put the MSI target address below 4GB
+			 */
+			msi_target_addr = BRCM_MSI_TARGET_ADDR_LT_4GB;
+		}
 	} else {
 		/*
 		 * Set simple configuration based on memory sizes
@@ -1163,7 +1473,12 @@ static int brcm_pcie_setup(struct brcm_p
 		 * and set the MSI target address accordingly.
 		 */
 		rc_bar2_offset = 0;
+
+		msi_target_addr = (rc_bar2_size >= 0x100000000ULL)
+			? BRCM_MSI_TARGET_ADDR_GT_4GB
+			: BRCM_MSI_TARGET_ADDR_LT_4GB;
 	}
+	pcie->msi_target_addr = msi_target_addr;
 
 	tmp = lower_32_bits(rc_bar2_offset);
 	tmp = INSERT_FIELD(tmp, PCIE_MISC_RC_BAR2_CONFIG_LO, SIZE,
@@ -1333,6 +1648,9 @@ static int brcm_pcie_resume(struct devic
 	if (ret)
 		return ret;
 
+	if (pcie->msi && pcie->msi_internal)
+		brcm_msi_set_regs(pcie->msi);
+
 	pcie->suspended = false;
 
 	return 0;
@@ -1340,6 +1658,7 @@ static int brcm_pcie_resume(struct devic
 
 static void _brcm_pcie_remove(struct brcm_pcie *pcie)
 {
+	brcm_msi_remove(pcie);
 	turn_off(pcie);
 	clk_disable_unprepare(pcie->clk);
 	clk_put(pcie->clk);
@@ -1368,7 +1687,7 @@ MODULE_DEVICE_TABLE(of, brcm_pcie_match)
 
 static int brcm_pcie_probe(struct platform_device *pdev)
 {
-	struct device_node *dn = pdev->dev.of_node;
+	struct device_node *dn = pdev->dev.of_node, *msi_dn;
 	const struct of_device_id *of_id;
 	const struct pcie_cfg_data *data;
 	int ret;
@@ -1448,6 +1767,20 @@ static int brcm_pcie_probe(struct platfo
 	if (ret)
 		goto fail;
 
+	msi_dn = of_parse_phandle(pcie->dn, "msi-parent", 0);
+	/* Use the internal MSI if no msi-parent property */
+	if (!msi_dn)
+		msi_dn = pcie->dn;
+
+	if (pci_msi_enabled() && msi_dn == pcie->dn) {
+		ret = brcm_pcie_enable_msi(pcie);
+		if (ret)
+			dev_err(pcie->dev,
+				"probe of internal MSI failed: %d)", ret);
+		else
+			pcie->msi_internal = true;
+	}
+
 	list_splice_init(&pcie->resources, &bridge->windows);
 	bridge->dev.parent = &pdev->dev;
 	bridge->busnr = 0;
@@ -1470,7 +1803,6 @@ static int brcm_pcie_probe(struct platfo
 	pcie->root_bus = bridge->bus;
 
 	return 0;
-
 fail:
 	_brcm_pcie_remove(pcie);
 	return ret;