summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/sysdev/fsl_msi.c
blob: e094367d7739e00f8949aab22de0c7c5f0fb1f9d (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
/*
 * Copyright (C) 2007-2008 Freescale Semiconductor, Inc. All rights reserved.
 *
 * Author: Tony Li <tony.li@freescale.com>
 *	   Jason Jin <Jason.jin@freescale.com>
 *
 * The hwirq alloc and free code reuse from sysdev/mpic_msi.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 2 of the
 * License.
 *
 */
#include <linux/irq.h>
#include <linux/bootmem.h>
#include <linux/msi.h>
#include <linux/pci.h>
#include <linux/of_platform.h>
#include <sysdev/fsl_soc.h>
#include <asm/prom.h>
#include <asm/hw_irq.h>
#include <asm/ppc-pci.h>
#include "fsl_msi.h"

struct fsl_msi_feature {
	u32 fsl_pic_ip;
	u32 msiir_offset;
};

static struct fsl_msi *fsl_msi;

static inline u32 fsl_msi_read(u32 __iomem *base, unsigned int reg)
{
	return in_be32(base + (reg >> 2));
}

/*
 * We do not need this actually. The MSIR register has been read once
 * in the cascade interrupt. So, this MSI interrupt has been acked
*/
static void fsl_msi_end_irq(unsigned int virq)
{
}

static struct irq_chip fsl_msi_chip = {
	.mask		= mask_msi_irq,
	.unmask		= unmask_msi_irq,
	.ack		= fsl_msi_end_irq,
	.name		= "FSL-MSI",
};

static int fsl_msi_host_map(struct irq_host *h, unsigned int virq,
				irq_hw_number_t hw)
{
	struct irq_chip *chip = &fsl_msi_chip;

	irq_to_desc(virq)->status |= IRQ_TYPE_EDGE_FALLING;

	set_irq_chip_and_handler(virq, chip, handle_edge_irq);

	return 0;
}

static struct irq_host_ops fsl_msi_host_ops = {
	.map = fsl_msi_host_map,
};

static int fsl_msi_init_allocator(struct fsl_msi *msi_data)
{
	int rc;

	rc = msi_bitmap_alloc(&msi_data->bitmap, NR_MSI_IRQS,
			      msi_data->irqhost->of_node);
	if (rc)
		return rc;

	rc = msi_bitmap_reserve_dt_hwirqs(&msi_data->bitmap);
	if (rc < 0) {
		msi_bitmap_free(&msi_data->bitmap);
		return rc;
	}

	return 0;
}

static int fsl_msi_check_device(struct pci_dev *pdev, int nvec, int type)
{
	if (type == PCI_CAP_ID_MSIX)
		pr_debug("fslmsi: MSI-X untested, trying anyway.\n");

	return 0;
}

static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
{
	struct msi_desc *entry;
	struct fsl_msi *msi_data = fsl_msi;

	list_for_each_entry(entry, &pdev->msi_list, list) {
		if (entry->irq == NO_IRQ)
			continue;
		set_irq_msi(entry->irq, NULL);
		msi_bitmap_free_hwirqs(&msi_data->bitmap,
				       virq_to_hw(entry->irq), 1);
		irq_dispose_mapping(entry->irq);
	}

	return;
}

static void fsl_compose_msi_msg(struct pci_dev *pdev, int hwirq,
				  struct msi_msg *msg)
{
	struct fsl_msi *msi_data = fsl_msi;
	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
	u32 base = 0;

	pci_bus_read_config_dword(hose->bus,
		PCI_DEVFN(0, 0), PCI_BASE_ADDRESS_0, &base);

	msg->address_lo = msi_data->msi_addr_lo + base;
	msg->address_hi = msi_data->msi_addr_hi;
	msg->data = hwirq;

	pr_debug("%s: allocated srs: %d, ibs: %d\n",
		__func__, hwirq / IRQS_PER_MSI_REG, hwirq % IRQS_PER_MSI_REG);
}

static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
{
	int rc, hwirq;
	unsigned int virq;
	struct msi_desc *entry;
	struct msi_msg msg;
	struct fsl_msi *msi_data = fsl_msi;

	list_for_each_entry(entry, &pdev->msi_list, list) {
		hwirq = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
		if (hwirq < 0) {
			rc = hwirq;
			pr_debug("%s: fail allocating msi interrupt\n",
					__func__);
			goto out_free;
		}

		virq = irq_create_mapping(msi_data->irqhost, hwirq);

		if (virq == NO_IRQ) {
			pr_debug("%s: fail mapping hwirq 0x%x\n",
					__func__, hwirq);
			msi_bitmap_free_hwirqs(&msi_data->bitmap, hwirq, 1);
			rc = -ENOSPC;
			goto out_free;
		}
		set_irq_msi(virq, entry);

		fsl_compose_msi_msg(pdev, hwirq, &msg);
		write_msi_msg(virq, &msg);
	}
	return 0;

out_free:
	return rc;
}

static void fsl_msi_cascade(unsigned int irq, struct irq_desc *desc)
{
	unsigned int cascade_irq;
	struct fsl_msi *msi_data = fsl_msi;
	int msir_index = -1;
	u32 msir_value = 0;
	u32 intr_index;
	u32 have_shift = 0;

	raw_spin_lock(&desc->lock);
	if ((msi_data->feature &  FSL_PIC_IP_MASK) == FSL_PIC_IP_IPIC) {
		if (desc->chip->mask_ack)
			desc->chip->mask_ack(irq);
		else {
			desc->chip->mask(irq);
			desc->chip->ack(irq);
		}
	}

	if (unlikely(desc->status & IRQ_INPROGRESS))
		goto unlock;

	msir_index = (int)desc->handler_data;

	if (msir_index >= NR_MSI_REG)
		cascade_irq = NO_IRQ;

	desc->status |= IRQ_INPROGRESS;
	switch (fsl_msi->feature & FSL_PIC_IP_MASK) {
	case FSL_PIC_IP_MPIC:
		msir_value = fsl_msi_read(msi_data->msi_regs,
			msir_index * 0x10);
		break;
	case FSL_PIC_IP_IPIC:
		msir_value = fsl_msi_read(msi_data->msi_regs, msir_index * 0x4);
		break;
	}

	while (msir_value) {
		intr_index = ffs(msir_value) - 1;

		cascade_irq = irq_linear_revmap(msi_data->irqhost,
				msir_index * IRQS_PER_MSI_REG +
					intr_index + have_shift);
		if (cascade_irq != NO_IRQ)
			generic_handle_irq(cascade_irq);
		have_shift += intr_index + 1;
		msir_value = msir_value >> (intr_index + 1);
	}
	desc->status &= ~IRQ_INPROGRESS;

	switch (msi_data->feature & FSL_PIC_IP_MASK) {
	case FSL_PIC_IP_MPIC:
		desc->chip->eoi(irq);
		break;
	case FSL_PIC_IP_IPIC:
		if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
			desc->chip->unmask(irq);
		break;
	}
unlock:
	raw_spin_unlock(&desc->lock);
}

static int __devinit fsl_of_msi_probe(struct of_device *dev,
				const struct of_device_id *match)
{
	struct fsl_msi *msi;
	struct resource res;
	int err, i, count;
	int rc;
	int virt_msir;
	const u32 *p;
	struct fsl_msi_feature *features = match->data;

	printk(KERN_DEBUG "Setting up Freescale MSI support\n");

	msi = kzalloc(sizeof(struct fsl_msi), GFP_KERNEL);
	if (!msi) {
		dev_err(&dev->dev, "No memory for MSI structure\n");
		err = -ENOMEM;
		goto error_out;
	}

	msi->irqhost = irq_alloc_host(dev->node, IRQ_HOST_MAP_LINEAR,
				      NR_MSI_IRQS, &fsl_msi_host_ops, 0);

	if (msi->irqhost == NULL) {
		dev_err(&dev->dev, "No memory for MSI irqhost\n");
		err = -ENOMEM;
		goto error_out;
	}

	/* Get the MSI reg base */
	err = of_address_to_resource(dev->node, 0, &res);
	if (err) {
		dev_err(&dev->dev, "%s resource error!\n",
				dev->node->full_name);
		goto error_out;
	}

	msi->msi_regs = ioremap(res.start, res.end - res.start + 1);
	if (!msi->msi_regs) {
		dev_err(&dev->dev, "ioremap problem failed\n");
		goto error_out;
	}

	msi->feature = features->fsl_pic_ip;

	msi->irqhost->host_data = msi;

	msi->msi_addr_hi = 0x0;
	msi->msi_addr_lo = features->msiir_offset + (res.start & 0xfffff);

	rc = fsl_msi_init_allocator(msi);
	if (rc) {
		dev_err(&dev->dev, "Error allocating MSI bitmap\n");
		goto error_out;
	}

	p = of_get_property(dev->node, "interrupts", &count);
	if (!p) {
		dev_err(&dev->dev, "no interrupts property found on %s\n",
				dev->node->full_name);
		err = -ENODEV;
		goto error_out;
	}
	if (count % 8 != 0) {
		dev_err(&dev->dev, "Malformed interrupts property on %s\n",
				dev->node->full_name);
		err = -EINVAL;
		goto error_out;
	}

	count /= sizeof(u32);
	for (i = 0; i < count / 2; i++) {
		if (i > NR_MSI_REG)
			break;
		virt_msir = irq_of_parse_and_map(dev->node, i);
		if (virt_msir != NO_IRQ) {
			set_irq_data(virt_msir, (void *)i);
			set_irq_chained_handler(virt_msir, fsl_msi_cascade);
		}
	}

	fsl_msi = msi;

	WARN_ON(ppc_md.setup_msi_irqs);
	ppc_md.setup_msi_irqs = fsl_setup_msi_irqs;
	ppc_md.teardown_msi_irqs = fsl_teardown_msi_irqs;
	ppc_md.msi_check_device = fsl_msi_check_device;
	return 0;
error_out:
	kfree(msi);
	return err;
}

static const struct fsl_msi_feature mpic_msi_feature = {
	.fsl_pic_ip = FSL_PIC_IP_MPIC,
	.msiir_offset = 0x140,
};

static const struct fsl_msi_feature ipic_msi_feature = {
	.fsl_pic_ip = FSL_PIC_IP_IPIC,
	.msiir_offset = 0x38,
};

static const struct of_device_id fsl_of_msi_ids[] = {
	{
		.compatible = "fsl,mpic-msi",
		.data = (void *)&mpic_msi_feature,
	},
	{
		.compatible = "fsl,ipic-msi",
		.data = (void *)&ipic_msi_feature,
	},
	{}
};

static struct of_platform_driver fsl_of_msi_driver = {
	.name = "fsl-msi",
	.match_table = fsl_of_msi_ids,
	.probe = fsl_of_msi_probe,
};

static __init int fsl_of_msi_init(void)
{
	return of_register_platform_driver(&fsl_of_msi_driver);
}

subsys_initcall(fsl_of_msi_init);
OpenPOWER on IntegriCloud