summaryrefslogtreecommitdiff
path: root/drivers/misc/cxl/vphb.c
blob: 7908633d9204b1ffd9cc588b3da0fd97eadcb1a5 (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
/*
 * Copyright 2014 IBM Corp.
 *
 * 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; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/pci.h>
#include <misc/cxl.h>
#include "cxl.h"

static int cxl_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
{
	if (dma_mask < DMA_BIT_MASK(64)) {
		pr_info("%s only 64bit DMA supported on CXL", __func__);
		return -EIO;
	}

	*(pdev->dev.dma_mask) = dma_mask;
	return 0;
}

static int cxl_pci_probe_mode(struct pci_bus *bus)
{
	return PCI_PROBE_NORMAL;
}

static int cxl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
{
	return -ENODEV;
}

static void cxl_teardown_msi_irqs(struct pci_dev *pdev)
{
	/*
	 * MSI should never be set but need still need to provide this call
	 * back.
	 */
}

static bool cxl_pci_enable_device_hook(struct pci_dev *dev)
{
	struct pci_controller *phb;
	struct cxl_afu *afu;
	struct cxl_context *ctx;

	phb = pci_bus_to_host(dev->bus);
	afu = (struct cxl_afu *)phb->private_data;

	if (!cxl_ops->link_ok(afu->adapter, afu)) {
		dev_warn(&dev->dev, "%s: Device link is down, refusing to enable AFU\n", __func__);
		return false;
	}

	set_dma_ops(&dev->dev, &dma_nommu_ops);
	set_dma_offset(&dev->dev, PAGE_OFFSET);

	/*
	 * Allocate a context to do cxl things too.  If we eventually do real
	 * DMA ops, we'll need a default context to attach them to
	 */
	ctx = cxl_dev_context_init(dev);
	if (IS_ERR(ctx))
		return false;
	dev->dev.archdata.cxl_ctx = ctx;

	return (cxl_ops->afu_check_and_enable(afu) == 0);
}

static void cxl_pci_disable_device(struct pci_dev *dev)
{
	struct cxl_context *ctx = cxl_get_context(dev);

	if (ctx) {
		if (ctx->status == STARTED) {
			dev_err(&dev->dev, "Default context started\n");
			return;
		}
		dev->dev.archdata.cxl_ctx = NULL;
		cxl_release_context(ctx);
	}
}

static resource_size_t cxl_pci_window_alignment(struct pci_bus *bus,
						unsigned long type)
{
	return 1;
}

static void cxl_pci_reset_secondary_bus(struct pci_dev *dev)
{
	/* Should we do an AFU reset here ? */
}

static int cxl_pcie_cfg_record(u8 bus, u8 devfn)
{
	return (bus << 8) + devfn;
}

static inline struct cxl_afu *pci_bus_to_afu(struct pci_bus *bus)
{
	struct pci_controller *phb = bus ? pci_bus_to_host(bus) : NULL;

	return phb ? phb->private_data : NULL;
}

static void cxl_afu_configured_put(struct cxl_afu *afu)
{
	atomic_dec_if_positive(&afu->configured_state);
}

static bool cxl_afu_configured_get(struct cxl_afu *afu)
{
	return atomic_inc_unless_negative(&afu->configured_state);
}

static inline int cxl_pcie_config_info(struct pci_bus *bus, unsigned int devfn,
				       struct cxl_afu *afu, int *_record)
{
	int record;

	record = cxl_pcie_cfg_record(bus->number, devfn);
	if (record > afu->crs_num)
		return PCIBIOS_DEVICE_NOT_FOUND;

	*_record = record;
	return 0;
}

static int cxl_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
				int offset, int len, u32 *val)
{
	int rc, record;
	struct cxl_afu *afu;
	u8 val8;
	u16 val16;
	u32 val32;

	afu = pci_bus_to_afu(bus);
	/* Grab a reader lock on afu. */
	if (afu == NULL || !cxl_afu_configured_get(afu))
		return PCIBIOS_DEVICE_NOT_FOUND;

	rc = cxl_pcie_config_info(bus, devfn, afu, &record);
	if (rc)
		goto out;

	switch (len) {
	case 1:
		rc = cxl_ops->afu_cr_read8(afu, record, offset,	&val8);
		*val = val8;
		break;
	case 2:
		rc = cxl_ops->afu_cr_read16(afu, record, offset, &val16);
		*val = val16;
		break;
	case 4:
		rc = cxl_ops->afu_cr_read32(afu, record, offset, &val32);
		*val = val32;
		break;
	default:
		WARN_ON(1);
	}

out:
	cxl_afu_configured_put(afu);
	return rc ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
}

static int cxl_pcie_write_config(struct pci_bus *bus, unsigned int devfn,
				 int offset, int len, u32 val)
{
	int rc, record;
	struct cxl_afu *afu;

	afu = pci_bus_to_afu(bus);
	/* Grab a reader lock on afu. */
	if (afu == NULL || !cxl_afu_configured_get(afu))
		return PCIBIOS_DEVICE_NOT_FOUND;

	rc = cxl_pcie_config_info(bus, devfn, afu, &record);
	if (rc)
		goto out;

	switch (len) {
	case 1:
		rc = cxl_ops->afu_cr_write8(afu, record, offset, val & 0xff);
		break;
	case 2:
		rc = cxl_ops->afu_cr_write16(afu, record, offset, val & 0xffff);
		break;
	case 4:
		rc = cxl_ops->afu_cr_write32(afu, record, offset, val);
		break;
	default:
		WARN_ON(1);
	}

out:
	cxl_afu_configured_put(afu);
	return rc ? PCIBIOS_SET_FAILED : PCIBIOS_SUCCESSFUL;
}

static struct pci_ops cxl_pcie_pci_ops =
{
	.read = cxl_pcie_read_config,
	.write = cxl_pcie_write_config,
};


static struct pci_controller_ops cxl_pci_controller_ops =
{
	.probe_mode = cxl_pci_probe_mode,
	.enable_device_hook = cxl_pci_enable_device_hook,
	.disable_device = cxl_pci_disable_device,
	.release_device = cxl_pci_disable_device,
	.window_alignment = cxl_pci_window_alignment,
	.reset_secondary_bus = cxl_pci_reset_secondary_bus,
	.setup_msi_irqs = cxl_setup_msi_irqs,
	.teardown_msi_irqs = cxl_teardown_msi_irqs,
	.dma_set_mask = cxl_dma_set_mask,
};

int cxl_pci_vphb_add(struct cxl_afu *afu)
{
	struct pci_controller *phb;
	struct device_node *vphb_dn;
	struct device *parent;

	/*
	 * If there are no AFU configuration records we won't have anything to
	 * expose under the vPHB, so skip creating one, returning success since
	 * this is still a valid case. This will also opt us out of EEH
	 * handling since we won't have anything special to do if there are no
	 * kernel drivers attached to the vPHB, and EEH handling is not yet
	 * supported in the peer model.
	 */
	if (!afu->crs_num)
		return 0;

	/* The parent device is the adapter. Reuse the device node of
	 * the adapter.
	 * We don't seem to care what device node is used for the vPHB,
	 * but tools such as lsvpd walk up the device parents looking
	 * for a valid location code, so we might as well show devices
	 * attached to the adapter as being located on that adapter.
	 */
	parent = afu->adapter->dev.parent;
	vphb_dn = parent->of_node;

	/* Alloc and setup PHB data structure */
	phb = pcibios_alloc_controller(vphb_dn);
	if (!phb)
		return -ENODEV;

	/* Setup parent in sysfs */
	phb->parent = parent;

	/* Setup the PHB using arch provided callback */
	phb->ops = &cxl_pcie_pci_ops;
	phb->cfg_addr = NULL;
	phb->cfg_data = NULL;
	phb->private_data = afu;
	phb->controller_ops = cxl_pci_controller_ops;

	/* Scan the bus */
	pcibios_scan_phb(phb);
	if (phb->bus == NULL)
		return -ENXIO;

	/* Set release hook on root bus */
	pci_set_host_bridge_release(to_pci_host_bridge(phb->bus->bridge),
				    pcibios_free_controller_deferred,
				    (void *) phb);

	/* Claim resources. This might need some rework as well depending
	 * whether we are doing probe-only or not, like assigning unassigned
	 * resources etc...
	 */
	pcibios_claim_one_bus(phb->bus);

	/* Add probed PCI devices to the device model */
	pci_bus_add_devices(phb->bus);

	afu->phb = phb;

	return 0;
}

void cxl_pci_vphb_remove(struct cxl_afu *afu)
{
	struct pci_controller *phb;

	/* If there is no configuration record we won't have one of these */
	if (!afu || !afu->phb)
		return;

	phb = afu->phb;
	afu->phb = NULL;

	pci_remove_root_bus(phb->bus);
	/*
	 * We don't free phb here - that's handled by
	 * pcibios_free_controller_deferred()
	 */
}

bool cxl_pci_is_vphb_device(struct pci_dev *dev)
{
	struct pci_controller *phb;

	phb = pci_bus_to_host(dev->bus);

	return (phb->ops == &cxl_pcie_pci_ops);
}

struct cxl_afu *cxl_pci_to_afu(struct pci_dev *dev)
{
	struct pci_controller *phb;

	phb = pci_bus_to_host(dev->bus);

	return (struct cxl_afu *)phb->private_data;
}
EXPORT_SYMBOL_GPL(cxl_pci_to_afu);

unsigned int cxl_pci_to_cfg_record(struct pci_dev *dev)
{
	return cxl_pcie_cfg_record(dev->bus->number, dev->devfn);
}
EXPORT_SYMBOL_GPL(cxl_pci_to_cfg_record);