summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms/pseries/msi.c
blob: f15222bbe136a1020de443d3ff6c434c152c8d4b (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
/*
 * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp.
 * Copyright 2006-2007 Michael Ellerman, 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; version 2 of the
 * License.
 *
 */

#include <linux/device.h>
#include <linux/irq.h>
#include <linux/msi.h>

#include <asm/rtas.h>
#include <asm/hw_irq.h>
#include <asm/ppc-pci.h>

static int query_token, change_token;

#define RTAS_QUERY_FN		0
#define RTAS_CHANGE_FN		1
#define RTAS_RESET_FN		2
#define RTAS_CHANGE_MSI_FN	3
#define RTAS_CHANGE_MSIX_FN	4

static struct pci_dn *get_pdn(struct pci_dev *pdev)
{
	struct device_node *dn;
	struct pci_dn *pdn;

	dn = pci_device_to_OF_node(pdev);
	if (!dn) {
		dev_dbg(&pdev->dev, "rtas_msi: No OF device node\n");
		return NULL;
	}

	pdn = PCI_DN(dn);
	if (!pdn) {
		dev_dbg(&pdev->dev, "rtas_msi: No PCI DN\n");
		return NULL;
	}

	return pdn;
}

/* RTAS Helpers */

static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs)
{
	u32 addr, seq_num, rtas_ret[3];
	unsigned long buid;
	int rc;

	addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
	buid = pdn->phb->buid;

	seq_num = 1;
	do {
		if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN)
			rc = rtas_call(change_token, 6, 4, rtas_ret, addr,
					BUID_HI(buid), BUID_LO(buid),
					func, num_irqs, seq_num);
		else
			rc = rtas_call(change_token, 6, 3, rtas_ret, addr,
					BUID_HI(buid), BUID_LO(buid),
					func, num_irqs, seq_num);

		seq_num = rtas_ret[1];
	} while (rtas_busy_delay(rc));

	/*
	 * If the RTAS call succeeded, check the number of irqs is actually
	 * what we asked for. If not, return an error.
	 */
	if (rc == 0 && rtas_ret[0] != num_irqs)
		rc = -ENOSPC;

	pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n",
		 func, num_irqs, rtas_ret[0], rc);

	return rc;
}

static void rtas_disable_msi(struct pci_dev *pdev)
{
	struct pci_dn *pdn;

	pdn = get_pdn(pdev);
	if (!pdn)
		return;

	if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0))
		pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
}

static int rtas_query_irq_number(struct pci_dn *pdn, int offset)
{
	u32 addr, rtas_ret[2];
	unsigned long buid;
	int rc;

	addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
	buid = pdn->phb->buid;

	do {
		rc = rtas_call(query_token, 4, 3, rtas_ret, addr,
			       BUID_HI(buid), BUID_LO(buid), offset);
	} while (rtas_busy_delay(rc));

	if (rc) {
		pr_debug("rtas_msi: error (%d) querying source number\n", rc);
		return rc;
	}

	return rtas_ret[0];
}

static void rtas_teardown_msi_irqs(struct pci_dev *pdev)
{
	struct msi_desc *entry;

	list_for_each_entry(entry, &pdev->msi_list, list) {
		if (entry->irq == NO_IRQ)
			continue;

		set_irq_msi(entry->irq, NULL);
		irq_dispose_mapping(entry->irq);
	}

	rtas_disable_msi(pdev);
}

static int check_req_msi(struct pci_dev *pdev, int nvec)
{
	struct device_node *dn;
	struct pci_dn *pdn;
	const u32 *req_msi;

	pdn = get_pdn(pdev);
	if (!pdn)
		return -ENODEV;

	dn = pdn->node;

	req_msi = of_get_property(dn, "ibm,req#msi", NULL);
	if (!req_msi) {
		pr_debug("rtas_msi: No ibm,req#msi on %s\n", dn->full_name);
		return -ENOENT;
	}

	if (*req_msi < nvec) {
		pr_debug("rtas_msi: ibm,req#msi requests < %d MSIs\n", nvec);
		return -ENOSPC;
	}

	return 0;
}

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

	return check_req_msi(pdev, nvec);
}

static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
{
	struct pci_dn *pdn;
	int hwirq, virq, i, rc;
	struct msi_desc *entry;
	struct msi_msg msg;

	pdn = get_pdn(pdev);
	if (!pdn)
		return -ENODEV;

	/*
	 * Try the new more explicit firmware interface, if that fails fall
	 * back to the old interface. The old interface is known to never
	 * return MSI-Xs.
	 */
	if (type == PCI_CAP_ID_MSI) {
		rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);

		if (rc) {
			pr_debug("rtas_msi: trying the old firmware call.\n");
			rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec);
		}
	} else
		rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);

	if (rc) {
		pr_debug("rtas_msi: rtas_change_msi() failed\n");
		return rc;
	}

	i = 0;
	list_for_each_entry(entry, &pdev->msi_list, list) {
		hwirq = rtas_query_irq_number(pdn, i);
		if (hwirq < 0) {
			pr_debug("rtas_msi: error (%d) getting hwirq\n", rc);
			return hwirq;
		}

		virq = irq_create_mapping(NULL, hwirq);

		if (virq == NO_IRQ) {
			pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq);
			return -ENOSPC;
		}

		dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq);
		set_irq_msi(virq, entry);

		/* Read config space back so we can restore after reset */
		read_msi_msg(virq, &msg);
		entry->msg = msg;

		unmask_msi_irq(virq);
	}

	return 0;
}

static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev)
{
	/* No LSI -> leave MSIs (if any) configured */
	if (pdev->irq == NO_IRQ) {
		dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n");
		return;
	}

	/* No MSI -> MSIs can't have been assigned by fw, leave LSI */
	if (check_req_msi(pdev, 1)) {
		dev_dbg(&pdev->dev, "rtas_msi: no req#msi, nothing to do.\n");
		return;
	}

	dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n");
	rtas_disable_msi(pdev);
}

static int rtas_msi_init(void)
{
	query_token  = rtas_token("ibm,query-interrupt-source-number");
	change_token = rtas_token("ibm,change-msi");

	if ((query_token == RTAS_UNKNOWN_SERVICE) ||
			(change_token == RTAS_UNKNOWN_SERVICE)) {
		pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n");
		return -1;
	}

	pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n");

	WARN_ON(ppc_md.setup_msi_irqs);
	ppc_md.setup_msi_irqs = rtas_setup_msi_irqs;
	ppc_md.teardown_msi_irqs = rtas_teardown_msi_irqs;
	ppc_md.msi_check_device = rtas_msi_check_device;

	WARN_ON(ppc_md.pci_irq_fixup);
	ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup;

	return 0;
}
arch_initcall(rtas_msi_init);