xref: /linux/drivers/iommu/irq_remapping.c (revision f9c41a62bba3f3f7ef3541b2a025e3371bcbba97)
1 #include <linux/seq_file.h>
2 #include <linux/cpumask.h>
3 #include <linux/kernel.h>
4 #include <linux/string.h>
5 #include <linux/errno.h>
6 #include <linux/msi.h>
7 #include <linux/irq.h>
8 #include <linux/pci.h>
9 
10 #include <asm/hw_irq.h>
11 #include <asm/irq_remapping.h>
12 #include <asm/processor.h>
13 #include <asm/x86_init.h>
14 #include <asm/apic.h>
15 
16 #include "irq_remapping.h"
17 
18 int irq_remapping_enabled;
19 
20 int disable_irq_remap;
21 int disable_sourceid_checking;
22 int no_x2apic_optout;
23 
24 static struct irq_remap_ops *remap_ops;
25 
26 static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec);
27 static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
28 				  int index, int sub_handle);
29 static int set_remapped_irq_affinity(struct irq_data *data,
30 				     const struct cpumask *mask,
31 				     bool force);
32 
33 static bool irq_remapped(struct irq_cfg *cfg)
34 {
35 	return (cfg->remapped == 1);
36 }
37 
38 static void irq_remapping_disable_io_apic(void)
39 {
40 	/*
41 	 * With interrupt-remapping, for now we will use virtual wire A
42 	 * mode, as virtual wire B is little complex (need to configure
43 	 * both IOAPIC RTE as well as interrupt-remapping table entry).
44 	 * As this gets called during crash dump, keep this simple for
45 	 * now.
46 	 */
47 	if (cpu_has_apic || apic_from_smp_config())
48 		disconnect_bsp_APIC(0);
49 }
50 
51 static int do_setup_msi_irqs(struct pci_dev *dev, int nvec)
52 {
53 	int node, ret, sub_handle, index = 0;
54 	unsigned int irq;
55 	struct msi_desc *msidesc;
56 
57 	nvec = __roundup_pow_of_two(nvec);
58 
59 	WARN_ON(!list_is_singular(&dev->msi_list));
60 	msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
61 	WARN_ON(msidesc->irq);
62 	WARN_ON(msidesc->msi_attrib.multiple);
63 
64 	node = dev_to_node(&dev->dev);
65 	irq = __create_irqs(get_nr_irqs_gsi(), nvec, node);
66 	if (irq == 0)
67 		return -ENOSPC;
68 
69 	msidesc->msi_attrib.multiple = ilog2(nvec);
70 	for (sub_handle = 0; sub_handle < nvec; sub_handle++) {
71 		if (!sub_handle) {
72 			index = msi_alloc_remapped_irq(dev, irq, nvec);
73 			if (index < 0) {
74 				ret = index;
75 				goto error;
76 			}
77 		} else {
78 			ret = msi_setup_remapped_irq(dev, irq + sub_handle,
79 						     index, sub_handle);
80 			if (ret < 0)
81 				goto error;
82 		}
83 		ret = setup_msi_irq(dev, msidesc, irq, sub_handle);
84 		if (ret < 0)
85 			goto error;
86 	}
87 	return 0;
88 
89 error:
90 	destroy_irqs(irq, nvec);
91 
92 	/*
93 	 * Restore altered MSI descriptor fields and prevent just destroyed
94 	 * IRQs from tearing down again in default_teardown_msi_irqs()
95 	 */
96 	msidesc->irq = 0;
97 	msidesc->msi_attrib.multiple = 0;
98 
99 	return ret;
100 }
101 
102 static int do_setup_msix_irqs(struct pci_dev *dev, int nvec)
103 {
104 	int node, ret, sub_handle, index = 0;
105 	struct msi_desc *msidesc;
106 	unsigned int irq;
107 
108 	node		= dev_to_node(&dev->dev);
109 	irq		= get_nr_irqs_gsi();
110 	sub_handle	= 0;
111 
112 	list_for_each_entry(msidesc, &dev->msi_list, list) {
113 
114 		irq = create_irq_nr(irq, node);
115 		if (irq == 0)
116 			return -1;
117 
118 		if (sub_handle == 0)
119 			ret = index = msi_alloc_remapped_irq(dev, irq, nvec);
120 		else
121 			ret = msi_setup_remapped_irq(dev, irq, index, sub_handle);
122 
123 		if (ret < 0)
124 			goto error;
125 
126 		ret = setup_msi_irq(dev, msidesc, irq, 0);
127 		if (ret < 0)
128 			goto error;
129 
130 		sub_handle += 1;
131 		irq        += 1;
132 	}
133 
134 	return 0;
135 
136 error:
137 	destroy_irq(irq);
138 	return ret;
139 }
140 
141 static int irq_remapping_setup_msi_irqs(struct pci_dev *dev,
142 					int nvec, int type)
143 {
144 	if (type == PCI_CAP_ID_MSI)
145 		return do_setup_msi_irqs(dev, nvec);
146 	else
147 		return do_setup_msix_irqs(dev, nvec);
148 }
149 
150 void eoi_ioapic_pin_remapped(int apic, int pin, int vector)
151 {
152 	/*
153 	 * Intr-remapping uses pin number as the virtual vector
154 	 * in the RTE. Actual vector is programmed in
155 	 * intr-remapping table entry. Hence for the io-apic
156 	 * EOI we use the pin number.
157 	 */
158 	io_apic_eoi(apic, pin);
159 }
160 
161 static void __init irq_remapping_modify_x86_ops(void)
162 {
163 	x86_io_apic_ops.disable		= irq_remapping_disable_io_apic;
164 	x86_io_apic_ops.set_affinity	= set_remapped_irq_affinity;
165 	x86_io_apic_ops.setup_entry	= setup_ioapic_remapped_entry;
166 	x86_io_apic_ops.eoi_ioapic_pin	= eoi_ioapic_pin_remapped;
167 	x86_msi.setup_msi_irqs		= irq_remapping_setup_msi_irqs;
168 	x86_msi.setup_hpet_msi		= setup_hpet_msi_remapped;
169 	x86_msi.compose_msi_msg		= compose_remapped_msi_msg;
170 }
171 
172 static __init int setup_nointremap(char *str)
173 {
174 	disable_irq_remap = 1;
175 	return 0;
176 }
177 early_param("nointremap", setup_nointremap);
178 
179 static __init int setup_irqremap(char *str)
180 {
181 	if (!str)
182 		return -EINVAL;
183 
184 	while (*str) {
185 		if (!strncmp(str, "on", 2))
186 			disable_irq_remap = 0;
187 		else if (!strncmp(str, "off", 3))
188 			disable_irq_remap = 1;
189 		else if (!strncmp(str, "nosid", 5))
190 			disable_sourceid_checking = 1;
191 		else if (!strncmp(str, "no_x2apic_optout", 16))
192 			no_x2apic_optout = 1;
193 
194 		str += strcspn(str, ",");
195 		while (*str == ',')
196 			str++;
197 	}
198 
199 	return 0;
200 }
201 early_param("intremap", setup_irqremap);
202 
203 void __init setup_irq_remapping_ops(void)
204 {
205 	remap_ops = &intel_irq_remap_ops;
206 
207 #ifdef CONFIG_AMD_IOMMU
208 	if (amd_iommu_irq_ops.prepare() == 0)
209 		remap_ops = &amd_iommu_irq_ops;
210 #endif
211 }
212 
213 int irq_remapping_supported(void)
214 {
215 	if (disable_irq_remap)
216 		return 0;
217 
218 	if (!remap_ops || !remap_ops->supported)
219 		return 0;
220 
221 	return remap_ops->supported();
222 }
223 
224 int __init irq_remapping_prepare(void)
225 {
226 	if (!remap_ops || !remap_ops->prepare)
227 		return -ENODEV;
228 
229 	return remap_ops->prepare();
230 }
231 
232 int __init irq_remapping_enable(void)
233 {
234 	int ret;
235 
236 	if (!remap_ops || !remap_ops->enable)
237 		return -ENODEV;
238 
239 	ret = remap_ops->enable();
240 
241 	if (irq_remapping_enabled)
242 		irq_remapping_modify_x86_ops();
243 
244 	return ret;
245 }
246 
247 void irq_remapping_disable(void)
248 {
249 	if (!irq_remapping_enabled ||
250 	    !remap_ops ||
251 	    !remap_ops->disable)
252 		return;
253 
254 	remap_ops->disable();
255 }
256 
257 int irq_remapping_reenable(int mode)
258 {
259 	if (!irq_remapping_enabled ||
260 	    !remap_ops ||
261 	    !remap_ops->reenable)
262 		return 0;
263 
264 	return remap_ops->reenable(mode);
265 }
266 
267 int __init irq_remap_enable_fault_handling(void)
268 {
269 	if (!irq_remapping_enabled)
270 		return 0;
271 
272 	if (!remap_ops || !remap_ops->enable_faulting)
273 		return -ENODEV;
274 
275 	return remap_ops->enable_faulting();
276 }
277 
278 int setup_ioapic_remapped_entry(int irq,
279 				struct IO_APIC_route_entry *entry,
280 				unsigned int destination, int vector,
281 				struct io_apic_irq_attr *attr)
282 {
283 	if (!remap_ops || !remap_ops->setup_ioapic_entry)
284 		return -ENODEV;
285 
286 	return remap_ops->setup_ioapic_entry(irq, entry, destination,
287 					     vector, attr);
288 }
289 
290 int set_remapped_irq_affinity(struct irq_data *data, const struct cpumask *mask,
291 			      bool force)
292 {
293 	if (!config_enabled(CONFIG_SMP) || !remap_ops ||
294 	    !remap_ops->set_affinity)
295 		return 0;
296 
297 	return remap_ops->set_affinity(data, mask, force);
298 }
299 
300 void free_remapped_irq(int irq)
301 {
302 	struct irq_cfg *cfg = irq_get_chip_data(irq);
303 
304 	if (!remap_ops || !remap_ops->free_irq)
305 		return;
306 
307 	if (irq_remapped(cfg))
308 		remap_ops->free_irq(irq);
309 }
310 
311 void compose_remapped_msi_msg(struct pci_dev *pdev,
312 			      unsigned int irq, unsigned int dest,
313 			      struct msi_msg *msg, u8 hpet_id)
314 {
315 	struct irq_cfg *cfg = irq_get_chip_data(irq);
316 
317 	if (!irq_remapped(cfg))
318 		native_compose_msi_msg(pdev, irq, dest, msg, hpet_id);
319 	else if (remap_ops && remap_ops->compose_msi_msg)
320 		remap_ops->compose_msi_msg(pdev, irq, dest, msg, hpet_id);
321 }
322 
323 static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec)
324 {
325 	if (!remap_ops || !remap_ops->msi_alloc_irq)
326 		return -ENODEV;
327 
328 	return remap_ops->msi_alloc_irq(pdev, irq, nvec);
329 }
330 
331 static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
332 				  int index, int sub_handle)
333 {
334 	if (!remap_ops || !remap_ops->msi_setup_irq)
335 		return -ENODEV;
336 
337 	return remap_ops->msi_setup_irq(pdev, irq, index, sub_handle);
338 }
339 
340 int setup_hpet_msi_remapped(unsigned int irq, unsigned int id)
341 {
342 	if (!remap_ops || !remap_ops->setup_hpet_msi)
343 		return -ENODEV;
344 
345 	return remap_ops->setup_hpet_msi(irq, id);
346 }
347 
348 void panic_if_irq_remap(const char *msg)
349 {
350 	if (irq_remapping_enabled)
351 		panic(msg);
352 }
353 
354 static void ir_ack_apic_edge(struct irq_data *data)
355 {
356 	ack_APIC_irq();
357 }
358 
359 static void ir_ack_apic_level(struct irq_data *data)
360 {
361 	ack_APIC_irq();
362 	eoi_ioapic_irq(data->irq, data->chip_data);
363 }
364 
365 static void ir_print_prefix(struct irq_data *data, struct seq_file *p)
366 {
367 	seq_printf(p, " IR-%s", data->chip->name);
368 }
369 
370 void irq_remap_modify_chip_defaults(struct irq_chip *chip)
371 {
372 	chip->irq_print_chip = ir_print_prefix;
373 	chip->irq_ack = ir_ack_apic_edge;
374 	chip->irq_eoi = ir_ack_apic_level;
375 	chip->irq_set_affinity = x86_io_apic_ops.set_affinity;
376 }
377 
378 bool setup_remapped_irq(int irq, struct irq_cfg *cfg, struct irq_chip *chip)
379 {
380 	if (!irq_remapped(cfg))
381 		return false;
382 	irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
383 	irq_remap_modify_chip_defaults(chip);
384 	return true;
385 }
386