xref: /linux/drivers/iommu/irq_remapping.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 irq_remap_broken;
22 int disable_sourceid_checking;
23 int no_x2apic_optout;
24 
25 static struct irq_remap_ops *remap_ops;
26 
27 static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec);
28 static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
29 				  int index, int sub_handle);
30 static int set_remapped_irq_affinity(struct irq_data *data,
31 				     const struct cpumask *mask,
32 				     bool force);
33 
34 static bool irq_remapped(struct irq_cfg *cfg)
35 {
36 	return (cfg->remapped == 1);
37 }
38 
39 static void irq_remapping_disable_io_apic(void)
40 {
41 	/*
42 	 * With interrupt-remapping, for now we will use virtual wire A
43 	 * mode, as virtual wire B is little complex (need to configure
44 	 * both IOAPIC RTE as well as interrupt-remapping table entry).
45 	 * As this gets called during crash dump, keep this simple for
46 	 * now.
47 	 */
48 	if (cpu_has_apic || apic_from_smp_config())
49 		disconnect_bsp_APIC(0);
50 }
51 
52 static int do_setup_msi_irqs(struct pci_dev *dev, int nvec)
53 {
54 	int node, ret, sub_handle, nvec_pow2, index = 0;
55 	unsigned int irq;
56 	struct msi_desc *msidesc;
57 
58 	WARN_ON(!list_is_singular(&dev->msi_list));
59 	msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
60 	WARN_ON(msidesc->irq);
61 	WARN_ON(msidesc->msi_attrib.multiple);
62 	WARN_ON(msidesc->nvec_used);
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 	nvec_pow2 = __roundup_pow_of_two(nvec);
70 	msidesc->nvec_used = nvec;
71 	msidesc->msi_attrib.multiple = ilog2(nvec_pow2);
72 	for (sub_handle = 0; sub_handle < nvec; sub_handle++) {
73 		if (!sub_handle) {
74 			index = msi_alloc_remapped_irq(dev, irq, nvec_pow2);
75 			if (index < 0) {
76 				ret = index;
77 				goto error;
78 			}
79 		} else {
80 			ret = msi_setup_remapped_irq(dev, irq + sub_handle,
81 						     index, sub_handle);
82 			if (ret < 0)
83 				goto error;
84 		}
85 		ret = setup_msi_irq(dev, msidesc, irq, sub_handle);
86 		if (ret < 0)
87 			goto error;
88 	}
89 	return 0;
90 
91 error:
92 	destroy_irqs(irq, nvec);
93 
94 	/*
95 	 * Restore altered MSI descriptor fields and prevent just destroyed
96 	 * IRQs from tearing down again in default_teardown_msi_irqs()
97 	 */
98 	msidesc->irq = 0;
99 	msidesc->nvec_used = 0;
100 	msidesc->msi_attrib.multiple = 0;
101 
102 	return ret;
103 }
104 
105 static int do_setup_msix_irqs(struct pci_dev *dev, int nvec)
106 {
107 	int node, ret, sub_handle, index = 0;
108 	struct msi_desc *msidesc;
109 	unsigned int irq;
110 
111 	node		= dev_to_node(&dev->dev);
112 	irq		= get_nr_irqs_gsi();
113 	sub_handle	= 0;
114 
115 	list_for_each_entry(msidesc, &dev->msi_list, list) {
116 
117 		irq = create_irq_nr(irq, node);
118 		if (irq == 0)
119 			return -1;
120 
121 		if (sub_handle == 0)
122 			ret = index = msi_alloc_remapped_irq(dev, irq, nvec);
123 		else
124 			ret = msi_setup_remapped_irq(dev, irq, index, sub_handle);
125 
126 		if (ret < 0)
127 			goto error;
128 
129 		ret = setup_msi_irq(dev, msidesc, irq, 0);
130 		if (ret < 0)
131 			goto error;
132 
133 		sub_handle += 1;
134 		irq        += 1;
135 	}
136 
137 	return 0;
138 
139 error:
140 	destroy_irq(irq);
141 	return ret;
142 }
143 
144 static int irq_remapping_setup_msi_irqs(struct pci_dev *dev,
145 					int nvec, int type)
146 {
147 	if (type == PCI_CAP_ID_MSI)
148 		return do_setup_msi_irqs(dev, nvec);
149 	else
150 		return do_setup_msix_irqs(dev, nvec);
151 }
152 
153 void eoi_ioapic_pin_remapped(int apic, int pin, int vector)
154 {
155 	/*
156 	 * Intr-remapping uses pin number as the virtual vector
157 	 * in the RTE. Actual vector is programmed in
158 	 * intr-remapping table entry. Hence for the io-apic
159 	 * EOI we use the pin number.
160 	 */
161 	io_apic_eoi(apic, pin);
162 }
163 
164 static void __init irq_remapping_modify_x86_ops(void)
165 {
166 	x86_io_apic_ops.disable		= irq_remapping_disable_io_apic;
167 	x86_io_apic_ops.set_affinity	= set_remapped_irq_affinity;
168 	x86_io_apic_ops.setup_entry	= setup_ioapic_remapped_entry;
169 	x86_io_apic_ops.eoi_ioapic_pin	= eoi_ioapic_pin_remapped;
170 	x86_msi.setup_msi_irqs		= irq_remapping_setup_msi_irqs;
171 	x86_msi.setup_hpet_msi		= setup_hpet_msi_remapped;
172 	x86_msi.compose_msi_msg		= compose_remapped_msi_msg;
173 }
174 
175 static __init int setup_nointremap(char *str)
176 {
177 	disable_irq_remap = 1;
178 	return 0;
179 }
180 early_param("nointremap", setup_nointremap);
181 
182 static __init int setup_irqremap(char *str)
183 {
184 	if (!str)
185 		return -EINVAL;
186 
187 	while (*str) {
188 		if (!strncmp(str, "on", 2))
189 			disable_irq_remap = 0;
190 		else if (!strncmp(str, "off", 3))
191 			disable_irq_remap = 1;
192 		else if (!strncmp(str, "nosid", 5))
193 			disable_sourceid_checking = 1;
194 		else if (!strncmp(str, "no_x2apic_optout", 16))
195 			no_x2apic_optout = 1;
196 
197 		str += strcspn(str, ",");
198 		while (*str == ',')
199 			str++;
200 	}
201 
202 	return 0;
203 }
204 early_param("intremap", setup_irqremap);
205 
206 void __init setup_irq_remapping_ops(void)
207 {
208 	remap_ops = &intel_irq_remap_ops;
209 
210 #ifdef CONFIG_AMD_IOMMU
211 	if (amd_iommu_irq_ops.prepare() == 0)
212 		remap_ops = &amd_iommu_irq_ops;
213 #endif
214 }
215 
216 void set_irq_remapping_broken(void)
217 {
218 	irq_remap_broken = 1;
219 }
220 
221 int irq_remapping_supported(void)
222 {
223 	if (disable_irq_remap)
224 		return 0;
225 
226 	if (!remap_ops || !remap_ops->supported)
227 		return 0;
228 
229 	return remap_ops->supported();
230 }
231 
232 int __init irq_remapping_prepare(void)
233 {
234 	if (!remap_ops || !remap_ops->prepare)
235 		return -ENODEV;
236 
237 	return remap_ops->prepare();
238 }
239 
240 int __init irq_remapping_enable(void)
241 {
242 	int ret;
243 
244 	if (!remap_ops || !remap_ops->enable)
245 		return -ENODEV;
246 
247 	ret = remap_ops->enable();
248 
249 	if (irq_remapping_enabled)
250 		irq_remapping_modify_x86_ops();
251 
252 	return ret;
253 }
254 
255 void irq_remapping_disable(void)
256 {
257 	if (!irq_remapping_enabled ||
258 	    !remap_ops ||
259 	    !remap_ops->disable)
260 		return;
261 
262 	remap_ops->disable();
263 }
264 
265 int irq_remapping_reenable(int mode)
266 {
267 	if (!irq_remapping_enabled ||
268 	    !remap_ops ||
269 	    !remap_ops->reenable)
270 		return 0;
271 
272 	return remap_ops->reenable(mode);
273 }
274 
275 int __init irq_remap_enable_fault_handling(void)
276 {
277 	if (!irq_remapping_enabled)
278 		return 0;
279 
280 	if (!remap_ops || !remap_ops->enable_faulting)
281 		return -ENODEV;
282 
283 	return remap_ops->enable_faulting();
284 }
285 
286 int setup_ioapic_remapped_entry(int irq,
287 				struct IO_APIC_route_entry *entry,
288 				unsigned int destination, int vector,
289 				struct io_apic_irq_attr *attr)
290 {
291 	if (!remap_ops || !remap_ops->setup_ioapic_entry)
292 		return -ENODEV;
293 
294 	return remap_ops->setup_ioapic_entry(irq, entry, destination,
295 					     vector, attr);
296 }
297 
298 int set_remapped_irq_affinity(struct irq_data *data, const struct cpumask *mask,
299 			      bool force)
300 {
301 	if (!config_enabled(CONFIG_SMP) || !remap_ops ||
302 	    !remap_ops->set_affinity)
303 		return 0;
304 
305 	return remap_ops->set_affinity(data, mask, force);
306 }
307 
308 void free_remapped_irq(int irq)
309 {
310 	struct irq_cfg *cfg = irq_get_chip_data(irq);
311 
312 	if (!remap_ops || !remap_ops->free_irq)
313 		return;
314 
315 	if (irq_remapped(cfg))
316 		remap_ops->free_irq(irq);
317 }
318 
319 void compose_remapped_msi_msg(struct pci_dev *pdev,
320 			      unsigned int irq, unsigned int dest,
321 			      struct msi_msg *msg, u8 hpet_id)
322 {
323 	struct irq_cfg *cfg = irq_get_chip_data(irq);
324 
325 	if (!irq_remapped(cfg))
326 		native_compose_msi_msg(pdev, irq, dest, msg, hpet_id);
327 	else if (remap_ops && remap_ops->compose_msi_msg)
328 		remap_ops->compose_msi_msg(pdev, irq, dest, msg, hpet_id);
329 }
330 
331 static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec)
332 {
333 	if (!remap_ops || !remap_ops->msi_alloc_irq)
334 		return -ENODEV;
335 
336 	return remap_ops->msi_alloc_irq(pdev, irq, nvec);
337 }
338 
339 static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
340 				  int index, int sub_handle)
341 {
342 	if (!remap_ops || !remap_ops->msi_setup_irq)
343 		return -ENODEV;
344 
345 	return remap_ops->msi_setup_irq(pdev, irq, index, sub_handle);
346 }
347 
348 int setup_hpet_msi_remapped(unsigned int irq, unsigned int id)
349 {
350 	if (!remap_ops || !remap_ops->setup_hpet_msi)
351 		return -ENODEV;
352 
353 	return remap_ops->setup_hpet_msi(irq, id);
354 }
355 
356 void panic_if_irq_remap(const char *msg)
357 {
358 	if (irq_remapping_enabled)
359 		panic(msg);
360 }
361 
362 static void ir_ack_apic_edge(struct irq_data *data)
363 {
364 	ack_APIC_irq();
365 }
366 
367 static void ir_ack_apic_level(struct irq_data *data)
368 {
369 	ack_APIC_irq();
370 	eoi_ioapic_irq(data->irq, data->chip_data);
371 }
372 
373 static void ir_print_prefix(struct irq_data *data, struct seq_file *p)
374 {
375 	seq_printf(p, " IR-%s", data->chip->name);
376 }
377 
378 void irq_remap_modify_chip_defaults(struct irq_chip *chip)
379 {
380 	chip->irq_print_chip = ir_print_prefix;
381 	chip->irq_ack = ir_ack_apic_edge;
382 	chip->irq_eoi = ir_ack_apic_level;
383 	chip->irq_set_affinity = x86_io_apic_ops.set_affinity;
384 }
385 
386 bool setup_remapped_irq(int irq, struct irq_cfg *cfg, struct irq_chip *chip)
387 {
388 	if (!irq_remapped(cfg))
389 		return false;
390 	irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
391 	irq_remap_modify_chip_defaults(chip);
392 	return true;
393 }
394