xref: /openbmc/linux/drivers/iommu/irq_remapping.c (revision 6774def6)
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 	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 	WARN_ON(msidesc->nvec_used);
64 
65 	irq = irq_alloc_hwirqs(nvec, dev_to_node(&dev->dev));
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 	irq_free_hwirqs(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 	sub_handle	= 0;
113 
114 	list_for_each_entry(msidesc, &dev->msi_list, list) {
115 
116 		irq = irq_alloc_hwirq(node);
117 		if (irq == 0)
118 			return -1;
119 
120 		if (sub_handle == 0)
121 			ret = index = msi_alloc_remapped_irq(dev, irq, nvec);
122 		else
123 			ret = msi_setup_remapped_irq(dev, irq, index, sub_handle);
124 
125 		if (ret < 0)
126 			goto error;
127 
128 		ret = setup_msi_irq(dev, msidesc, irq, 0);
129 		if (ret < 0)
130 			goto error;
131 
132 		sub_handle += 1;
133 		irq        += 1;
134 	}
135 
136 	return 0;
137 
138 error:
139 	irq_free_hwirq(irq);
140 	return ret;
141 }
142 
143 static int irq_remapping_setup_msi_irqs(struct pci_dev *dev,
144 					int nvec, int type)
145 {
146 	if (type == PCI_CAP_ID_MSI)
147 		return do_setup_msi_irqs(dev, nvec);
148 	else
149 		return do_setup_msix_irqs(dev, nvec);
150 }
151 
152 static void eoi_ioapic_pin_remapped(int apic, int pin, int vector)
153 {
154 	/*
155 	 * Intr-remapping uses pin number as the virtual vector
156 	 * in the RTE. Actual vector is programmed in
157 	 * intr-remapping table entry. Hence for the io-apic
158 	 * EOI we use the pin number.
159 	 */
160 	io_apic_eoi(apic, pin);
161 }
162 
163 static void __init irq_remapping_modify_x86_ops(void)
164 {
165 	x86_io_apic_ops.disable		= irq_remapping_disable_io_apic;
166 	x86_io_apic_ops.set_affinity	= set_remapped_irq_affinity;
167 	x86_io_apic_ops.setup_entry	= setup_ioapic_remapped_entry;
168 	x86_io_apic_ops.eoi_ioapic_pin	= eoi_ioapic_pin_remapped;
169 	x86_msi.setup_msi_irqs		= irq_remapping_setup_msi_irqs;
170 	x86_msi.setup_hpet_msi		= setup_hpet_msi_remapped;
171 	x86_msi.compose_msi_msg		= compose_remapped_msi_msg;
172 }
173 
174 static __init int setup_nointremap(char *str)
175 {
176 	disable_irq_remap = 1;
177 	return 0;
178 }
179 early_param("nointremap", setup_nointremap);
180 
181 static __init int setup_irqremap(char *str)
182 {
183 	if (!str)
184 		return -EINVAL;
185 
186 	while (*str) {
187 		if (!strncmp(str, "on", 2))
188 			disable_irq_remap = 0;
189 		else if (!strncmp(str, "off", 3))
190 			disable_irq_remap = 1;
191 		else if (!strncmp(str, "nosid", 5))
192 			disable_sourceid_checking = 1;
193 		else if (!strncmp(str, "no_x2apic_optout", 16))
194 			no_x2apic_optout = 1;
195 
196 		str += strcspn(str, ",");
197 		while (*str == ',')
198 			str++;
199 	}
200 
201 	return 0;
202 }
203 early_param("intremap", setup_irqremap);
204 
205 void __init setup_irq_remapping_ops(void)
206 {
207 	remap_ops = &intel_irq_remap_ops;
208 
209 #ifdef CONFIG_AMD_IOMMU
210 	if (amd_iommu_irq_ops.prepare() == 0)
211 		remap_ops = &amd_iommu_irq_ops;
212 #endif
213 }
214 
215 void set_irq_remapping_broken(void)
216 {
217 	irq_remap_broken = 1;
218 }
219 
220 int irq_remapping_supported(void)
221 {
222 	if (disable_irq_remap)
223 		return 0;
224 
225 	if (!remap_ops || !remap_ops->supported)
226 		return 0;
227 
228 	return remap_ops->supported();
229 }
230 
231 int __init irq_remapping_prepare(void)
232 {
233 	if (!remap_ops || !remap_ops->prepare)
234 		return -ENODEV;
235 
236 	return remap_ops->prepare();
237 }
238 
239 int __init irq_remapping_enable(void)
240 {
241 	int ret;
242 
243 	if (!remap_ops || !remap_ops->enable)
244 		return -ENODEV;
245 
246 	ret = remap_ops->enable();
247 
248 	if (irq_remapping_enabled)
249 		irq_remapping_modify_x86_ops();
250 
251 	return ret;
252 }
253 
254 void irq_remapping_disable(void)
255 {
256 	if (!irq_remapping_enabled ||
257 	    !remap_ops ||
258 	    !remap_ops->disable)
259 		return;
260 
261 	remap_ops->disable();
262 }
263 
264 int irq_remapping_reenable(int mode)
265 {
266 	if (!irq_remapping_enabled ||
267 	    !remap_ops ||
268 	    !remap_ops->reenable)
269 		return 0;
270 
271 	return remap_ops->reenable(mode);
272 }
273 
274 int __init irq_remap_enable_fault_handling(void)
275 {
276 	if (!irq_remapping_enabled)
277 		return 0;
278 
279 	if (!remap_ops || !remap_ops->enable_faulting)
280 		return -ENODEV;
281 
282 	return remap_ops->enable_faulting();
283 }
284 
285 int setup_ioapic_remapped_entry(int irq,
286 				struct IO_APIC_route_entry *entry,
287 				unsigned int destination, int vector,
288 				struct io_apic_irq_attr *attr)
289 {
290 	if (!remap_ops || !remap_ops->setup_ioapic_entry)
291 		return -ENODEV;
292 
293 	return remap_ops->setup_ioapic_entry(irq, entry, destination,
294 					     vector, attr);
295 }
296 
297 static int set_remapped_irq_affinity(struct irq_data *data,
298 				     const struct cpumask *mask, bool force)
299 {
300 	if (!config_enabled(CONFIG_SMP) || !remap_ops ||
301 	    !remap_ops->set_affinity)
302 		return 0;
303 
304 	return remap_ops->set_affinity(data, mask, force);
305 }
306 
307 void free_remapped_irq(int irq)
308 {
309 	struct irq_cfg *cfg = irq_get_chip_data(irq);
310 
311 	if (!remap_ops || !remap_ops->free_irq)
312 		return;
313 
314 	if (irq_remapped(cfg))
315 		remap_ops->free_irq(irq);
316 }
317 
318 void compose_remapped_msi_msg(struct pci_dev *pdev,
319 			      unsigned int irq, unsigned int dest,
320 			      struct msi_msg *msg, u8 hpet_id)
321 {
322 	struct irq_cfg *cfg = irq_get_chip_data(irq);
323 
324 	if (!irq_remapped(cfg))
325 		native_compose_msi_msg(pdev, irq, dest, msg, hpet_id);
326 	else if (remap_ops && remap_ops->compose_msi_msg)
327 		remap_ops->compose_msi_msg(pdev, irq, dest, msg, hpet_id);
328 }
329 
330 static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec)
331 {
332 	if (!remap_ops || !remap_ops->msi_alloc_irq)
333 		return -ENODEV;
334 
335 	return remap_ops->msi_alloc_irq(pdev, irq, nvec);
336 }
337 
338 static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
339 				  int index, int sub_handle)
340 {
341 	if (!remap_ops || !remap_ops->msi_setup_irq)
342 		return -ENODEV;
343 
344 	return remap_ops->msi_setup_irq(pdev, irq, index, sub_handle);
345 }
346 
347 int setup_hpet_msi_remapped(unsigned int irq, unsigned int id)
348 {
349 	int ret;
350 
351 	if (!remap_ops || !remap_ops->alloc_hpet_msi)
352 		return -ENODEV;
353 
354 	ret = remap_ops->alloc_hpet_msi(irq, id);
355 	if (ret)
356 		return -EINVAL;
357 
358 	return default_setup_hpet_msi(irq, id);
359 }
360 
361 void panic_if_irq_remap(const char *msg)
362 {
363 	if (irq_remapping_enabled)
364 		panic(msg);
365 }
366 
367 static void ir_ack_apic_edge(struct irq_data *data)
368 {
369 	ack_APIC_irq();
370 }
371 
372 static void ir_ack_apic_level(struct irq_data *data)
373 {
374 	ack_APIC_irq();
375 	eoi_ioapic_irq(data->irq, data->chip_data);
376 }
377 
378 static void ir_print_prefix(struct irq_data *data, struct seq_file *p)
379 {
380 	seq_printf(p, " IR-%s", data->chip->name);
381 }
382 
383 void irq_remap_modify_chip_defaults(struct irq_chip *chip)
384 {
385 	chip->irq_print_chip = ir_print_prefix;
386 	chip->irq_ack = ir_ack_apic_edge;
387 	chip->irq_eoi = ir_ack_apic_level;
388 	chip->irq_set_affinity = x86_io_apic_ops.set_affinity;
389 }
390 
391 bool setup_remapped_irq(int irq, struct irq_cfg *cfg, struct irq_chip *chip)
392 {
393 	if (!irq_remapped(cfg))
394 		return false;
395 	irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
396 	irq_remap_modify_chip_defaults(chip);
397 	return true;
398 }
399