xref: /linux/drivers/iommu/irq_remapping.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
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 #include <asm/hpet.h>
16 
17 #include "irq_remapping.h"
18 
19 int irq_remapping_enabled;
20 
21 int disable_irq_remap;
22 int irq_remap_broken;
23 int disable_sourceid_checking;
24 int no_x2apic_optout;
25 
26 static struct irq_remap_ops *remap_ops;
27 
28 static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec);
29 static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
30 				  int index, int sub_handle);
31 static int set_remapped_irq_affinity(struct irq_data *data,
32 				     const struct cpumask *mask,
33 				     bool force);
34 
35 static bool irq_remapped(struct irq_cfg *cfg)
36 {
37 	return (cfg->remapped == 1);
38 }
39 
40 static void irq_remapping_disable_io_apic(void)
41 {
42 	/*
43 	 * With interrupt-remapping, for now we will use virtual wire A
44 	 * mode, as virtual wire B is little complex (need to configure
45 	 * both IOAPIC RTE as well as interrupt-remapping table entry).
46 	 * As this gets called during crash dump, keep this simple for
47 	 * now.
48 	 */
49 	if (cpu_has_apic || apic_from_smp_config())
50 		disconnect_bsp_APIC(0);
51 }
52 
53 static int do_setup_msi_irqs(struct pci_dev *dev, int nvec)
54 {
55 	int ret, sub_handle, nvec_pow2, index = 0;
56 	unsigned int irq;
57 	struct msi_desc *msidesc;
58 
59 	msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
60 
61 	irq = irq_alloc_hwirqs(nvec, dev_to_node(&dev->dev));
62 	if (irq == 0)
63 		return -ENOSPC;
64 
65 	nvec_pow2 = __roundup_pow_of_two(nvec);
66 	for (sub_handle = 0; sub_handle < nvec; sub_handle++) {
67 		if (!sub_handle) {
68 			index = msi_alloc_remapped_irq(dev, irq, nvec_pow2);
69 			if (index < 0) {
70 				ret = index;
71 				goto error;
72 			}
73 		} else {
74 			ret = msi_setup_remapped_irq(dev, irq + sub_handle,
75 						     index, sub_handle);
76 			if (ret < 0)
77 				goto error;
78 		}
79 		ret = setup_msi_irq(dev, msidesc, irq, sub_handle);
80 		if (ret < 0)
81 			goto error;
82 	}
83 	return 0;
84 
85 error:
86 	irq_free_hwirqs(irq, nvec);
87 
88 	/*
89 	 * Restore altered MSI descriptor fields and prevent just destroyed
90 	 * IRQs from tearing down again in default_teardown_msi_irqs()
91 	 */
92 	msidesc->irq = 0;
93 
94 	return ret;
95 }
96 
97 static int do_setup_msix_irqs(struct pci_dev *dev, int nvec)
98 {
99 	int node, ret, sub_handle, index = 0;
100 	struct msi_desc *msidesc;
101 	unsigned int irq;
102 
103 	node		= dev_to_node(&dev->dev);
104 	sub_handle	= 0;
105 
106 	list_for_each_entry(msidesc, &dev->msi_list, list) {
107 
108 		irq = irq_alloc_hwirq(node);
109 		if (irq == 0)
110 			return -1;
111 
112 		if (sub_handle == 0)
113 			ret = index = msi_alloc_remapped_irq(dev, irq, nvec);
114 		else
115 			ret = msi_setup_remapped_irq(dev, irq, index, sub_handle);
116 
117 		if (ret < 0)
118 			goto error;
119 
120 		ret = setup_msi_irq(dev, msidesc, irq, 0);
121 		if (ret < 0)
122 			goto error;
123 
124 		sub_handle += 1;
125 		irq        += 1;
126 	}
127 
128 	return 0;
129 
130 error:
131 	irq_free_hwirq(irq);
132 	return ret;
133 }
134 
135 static int irq_remapping_setup_msi_irqs(struct pci_dev *dev,
136 					int nvec, int type)
137 {
138 	if (type == PCI_CAP_ID_MSI)
139 		return do_setup_msi_irqs(dev, nvec);
140 	else
141 		return do_setup_msix_irqs(dev, nvec);
142 }
143 
144 static void eoi_ioapic_pin_remapped(int apic, int pin, int vector)
145 {
146 	/*
147 	 * Intr-remapping uses pin number as the virtual vector
148 	 * in the RTE. Actual vector is programmed in
149 	 * intr-remapping table entry. Hence for the io-apic
150 	 * EOI we use the pin number.
151 	 */
152 	io_apic_eoi(apic, pin);
153 }
154 
155 static void __init irq_remapping_modify_x86_ops(void)
156 {
157 	x86_io_apic_ops.disable		= irq_remapping_disable_io_apic;
158 	x86_io_apic_ops.set_affinity	= set_remapped_irq_affinity;
159 	x86_io_apic_ops.setup_entry	= setup_ioapic_remapped_entry;
160 	x86_io_apic_ops.eoi_ioapic_pin	= eoi_ioapic_pin_remapped;
161 	x86_msi.setup_msi_irqs		= irq_remapping_setup_msi_irqs;
162 	x86_msi.setup_hpet_msi		= setup_hpet_msi_remapped;
163 	x86_msi.compose_msi_msg		= compose_remapped_msi_msg;
164 }
165 
166 static __init int setup_nointremap(char *str)
167 {
168 	disable_irq_remap = 1;
169 	return 0;
170 }
171 early_param("nointremap", setup_nointremap);
172 
173 static __init int setup_irqremap(char *str)
174 {
175 	if (!str)
176 		return -EINVAL;
177 
178 	while (*str) {
179 		if (!strncmp(str, "on", 2))
180 			disable_irq_remap = 0;
181 		else if (!strncmp(str, "off", 3))
182 			disable_irq_remap = 1;
183 		else if (!strncmp(str, "nosid", 5))
184 			disable_sourceid_checking = 1;
185 		else if (!strncmp(str, "no_x2apic_optout", 16))
186 			no_x2apic_optout = 1;
187 
188 		str += strcspn(str, ",");
189 		while (*str == ',')
190 			str++;
191 	}
192 
193 	return 0;
194 }
195 early_param("intremap", setup_irqremap);
196 
197 void __init setup_irq_remapping_ops(void)
198 {
199 	remap_ops = &intel_irq_remap_ops;
200 
201 #ifdef CONFIG_AMD_IOMMU
202 	if (amd_iommu_irq_ops.prepare() == 0)
203 		remap_ops = &amd_iommu_irq_ops;
204 #endif
205 }
206 
207 void set_irq_remapping_broken(void)
208 {
209 	irq_remap_broken = 1;
210 }
211 
212 int irq_remapping_supported(void)
213 {
214 	if (disable_irq_remap)
215 		return 0;
216 
217 	if (!remap_ops || !remap_ops->supported)
218 		return 0;
219 
220 	return remap_ops->supported();
221 }
222 
223 int __init irq_remapping_prepare(void)
224 {
225 	if (!remap_ops || !remap_ops->prepare)
226 		return -ENODEV;
227 
228 	return remap_ops->prepare();
229 }
230 
231 int __init irq_remapping_enable(void)
232 {
233 	int ret;
234 
235 	if (!remap_ops || !remap_ops->enable)
236 		return -ENODEV;
237 
238 	ret = remap_ops->enable();
239 
240 	if (irq_remapping_enabled)
241 		irq_remapping_modify_x86_ops();
242 
243 	return ret;
244 }
245 
246 void irq_remapping_disable(void)
247 {
248 	if (!irq_remapping_enabled ||
249 	    !remap_ops ||
250 	    !remap_ops->disable)
251 		return;
252 
253 	remap_ops->disable();
254 }
255 
256 int irq_remapping_reenable(int mode)
257 {
258 	if (!irq_remapping_enabled ||
259 	    !remap_ops ||
260 	    !remap_ops->reenable)
261 		return 0;
262 
263 	return remap_ops->reenable(mode);
264 }
265 
266 int __init irq_remap_enable_fault_handling(void)
267 {
268 	if (!irq_remapping_enabled)
269 		return 0;
270 
271 	if (!remap_ops || !remap_ops->enable_faulting)
272 		return -ENODEV;
273 
274 	return remap_ops->enable_faulting();
275 }
276 
277 int setup_ioapic_remapped_entry(int irq,
278 				struct IO_APIC_route_entry *entry,
279 				unsigned int destination, int vector,
280 				struct io_apic_irq_attr *attr)
281 {
282 	if (!remap_ops || !remap_ops->setup_ioapic_entry)
283 		return -ENODEV;
284 
285 	return remap_ops->setup_ioapic_entry(irq, entry, destination,
286 					     vector, attr);
287 }
288 
289 static int set_remapped_irq_affinity(struct irq_data *data,
290 				     const struct cpumask *mask, bool force)
291 {
292 	if (!config_enabled(CONFIG_SMP) || !remap_ops ||
293 	    !remap_ops->set_affinity)
294 		return 0;
295 
296 	return remap_ops->set_affinity(data, mask, force);
297 }
298 
299 void free_remapped_irq(int irq)
300 {
301 	struct irq_cfg *cfg = irq_cfg(irq);
302 
303 	if (!remap_ops || !remap_ops->free_irq)
304 		return;
305 
306 	if (irq_remapped(cfg))
307 		remap_ops->free_irq(irq);
308 }
309 
310 void compose_remapped_msi_msg(struct pci_dev *pdev,
311 			      unsigned int irq, unsigned int dest,
312 			      struct msi_msg *msg, u8 hpet_id)
313 {
314 	struct irq_cfg *cfg = irq_cfg(irq);
315 
316 	if (!irq_remapped(cfg))
317 		native_compose_msi_msg(pdev, irq, dest, msg, hpet_id);
318 	else if (remap_ops && remap_ops->compose_msi_msg)
319 		remap_ops->compose_msi_msg(pdev, irq, dest, msg, hpet_id);
320 }
321 
322 static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec)
323 {
324 	if (!remap_ops || !remap_ops->msi_alloc_irq)
325 		return -ENODEV;
326 
327 	return remap_ops->msi_alloc_irq(pdev, irq, nvec);
328 }
329 
330 static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
331 				  int index, int sub_handle)
332 {
333 	if (!remap_ops || !remap_ops->msi_setup_irq)
334 		return -ENODEV;
335 
336 	return remap_ops->msi_setup_irq(pdev, irq, index, sub_handle);
337 }
338 
339 int setup_hpet_msi_remapped(unsigned int irq, unsigned int id)
340 {
341 	int ret;
342 
343 	if (!remap_ops || !remap_ops->alloc_hpet_msi)
344 		return -ENODEV;
345 
346 	ret = remap_ops->alloc_hpet_msi(irq, id);
347 	if (ret)
348 		return -EINVAL;
349 
350 	return default_setup_hpet_msi(irq, id);
351 }
352 
353 void panic_if_irq_remap(const char *msg)
354 {
355 	if (irq_remapping_enabled)
356 		panic(msg);
357 }
358 
359 static void ir_ack_apic_edge(struct irq_data *data)
360 {
361 	ack_APIC_irq();
362 }
363 
364 static void ir_ack_apic_level(struct irq_data *data)
365 {
366 	ack_APIC_irq();
367 	eoi_ioapic_irq(data->irq, irqd_cfg(data));
368 }
369 
370 static void ir_print_prefix(struct irq_data *data, struct seq_file *p)
371 {
372 	seq_printf(p, " IR-%s", data->chip->name);
373 }
374 
375 void irq_remap_modify_chip_defaults(struct irq_chip *chip)
376 {
377 	chip->irq_print_chip = ir_print_prefix;
378 	chip->irq_ack = ir_ack_apic_edge;
379 	chip->irq_eoi = ir_ack_apic_level;
380 	chip->irq_set_affinity = x86_io_apic_ops.set_affinity;
381 }
382 
383 bool setup_remapped_irq(int irq, struct irq_cfg *cfg, struct irq_chip *chip)
384 {
385 	if (!irq_remapped(cfg))
386 		return false;
387 	irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
388 	irq_remap_modify_chip_defaults(chip);
389 	return true;
390 }
391