xref: /openbmc/linux/drivers/iommu/irq_remapping.c (revision d2999e1b)
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 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 	irq = irq_alloc_hwirqs(nvec, dev_to_node(&dev->dev));
65 	if (irq == 0)
66 		return -ENOSPC;
67 
68 	nvec_pow2 = __roundup_pow_of_two(nvec);
69 	msidesc->nvec_used = nvec;
70 	msidesc->msi_attrib.multiple = ilog2(nvec_pow2);
71 	for (sub_handle = 0; sub_handle < nvec; sub_handle++) {
72 		if (!sub_handle) {
73 			index = msi_alloc_remapped_irq(dev, irq, nvec_pow2);
74 			if (index < 0) {
75 				ret = index;
76 				goto error;
77 			}
78 		} else {
79 			ret = msi_setup_remapped_irq(dev, irq + sub_handle,
80 						     index, sub_handle);
81 			if (ret < 0)
82 				goto error;
83 		}
84 		ret = setup_msi_irq(dev, msidesc, irq, sub_handle);
85 		if (ret < 0)
86 			goto error;
87 	}
88 	return 0;
89 
90 error:
91 	irq_free_hwirqs(irq, nvec);
92 
93 	/*
94 	 * Restore altered MSI descriptor fields and prevent just destroyed
95 	 * IRQs from tearing down again in default_teardown_msi_irqs()
96 	 */
97 	msidesc->irq = 0;
98 	msidesc->nvec_used = 0;
99 	msidesc->msi_attrib.multiple = 0;
100 
101 	return ret;
102 }
103 
104 static int do_setup_msix_irqs(struct pci_dev *dev, int nvec)
105 {
106 	int node, ret, sub_handle, index = 0;
107 	struct msi_desc *msidesc;
108 	unsigned int irq;
109 
110 	node		= dev_to_node(&dev->dev);
111 	sub_handle	= 0;
112 
113 	list_for_each_entry(msidesc, &dev->msi_list, list) {
114 
115 		irq = irq_alloc_hwirq(node);
116 		if (irq == 0)
117 			return -1;
118 
119 		if (sub_handle == 0)
120 			ret = index = msi_alloc_remapped_irq(dev, irq, nvec);
121 		else
122 			ret = msi_setup_remapped_irq(dev, irq, index, sub_handle);
123 
124 		if (ret < 0)
125 			goto error;
126 
127 		ret = setup_msi_irq(dev, msidesc, irq, 0);
128 		if (ret < 0)
129 			goto error;
130 
131 		sub_handle += 1;
132 		irq        += 1;
133 	}
134 
135 	return 0;
136 
137 error:
138 	irq_free_hwirq(irq);
139 	return ret;
140 }
141 
142 static int irq_remapping_setup_msi_irqs(struct pci_dev *dev,
143 					int nvec, int type)
144 {
145 	if (type == PCI_CAP_ID_MSI)
146 		return do_setup_msi_irqs(dev, nvec);
147 	else
148 		return do_setup_msix_irqs(dev, nvec);
149 }
150 
151 static void eoi_ioapic_pin_remapped(int apic, int pin, int vector)
152 {
153 	/*
154 	 * Intr-remapping uses pin number as the virtual vector
155 	 * in the RTE. Actual vector is programmed in
156 	 * intr-remapping table entry. Hence for the io-apic
157 	 * EOI we use the pin number.
158 	 */
159 	io_apic_eoi(apic, pin);
160 }
161 
162 static void __init irq_remapping_modify_x86_ops(void)
163 {
164 	x86_io_apic_ops.disable		= irq_remapping_disable_io_apic;
165 	x86_io_apic_ops.set_affinity	= set_remapped_irq_affinity;
166 	x86_io_apic_ops.setup_entry	= setup_ioapic_remapped_entry;
167 	x86_io_apic_ops.eoi_ioapic_pin	= eoi_ioapic_pin_remapped;
168 	x86_msi.setup_msi_irqs		= irq_remapping_setup_msi_irqs;
169 	x86_msi.setup_hpet_msi		= setup_hpet_msi_remapped;
170 	x86_msi.compose_msi_msg		= compose_remapped_msi_msg;
171 }
172 
173 static __init int setup_nointremap(char *str)
174 {
175 	disable_irq_remap = 1;
176 	return 0;
177 }
178 early_param("nointremap", setup_nointremap);
179 
180 static __init int setup_irqremap(char *str)
181 {
182 	if (!str)
183 		return -EINVAL;
184 
185 	while (*str) {
186 		if (!strncmp(str, "on", 2))
187 			disable_irq_remap = 0;
188 		else if (!strncmp(str, "off", 3))
189 			disable_irq_remap = 1;
190 		else if (!strncmp(str, "nosid", 5))
191 			disable_sourceid_checking = 1;
192 		else if (!strncmp(str, "no_x2apic_optout", 16))
193 			no_x2apic_optout = 1;
194 
195 		str += strcspn(str, ",");
196 		while (*str == ',')
197 			str++;
198 	}
199 
200 	return 0;
201 }
202 early_param("intremap", setup_irqremap);
203 
204 void __init setup_irq_remapping_ops(void)
205 {
206 	remap_ops = &intel_irq_remap_ops;
207 
208 #ifdef CONFIG_AMD_IOMMU
209 	if (amd_iommu_irq_ops.prepare() == 0)
210 		remap_ops = &amd_iommu_irq_ops;
211 #endif
212 }
213 
214 void set_irq_remapping_broken(void)
215 {
216 	irq_remap_broken = 1;
217 }
218 
219 int irq_remapping_supported(void)
220 {
221 	if (disable_irq_remap)
222 		return 0;
223 
224 	if (!remap_ops || !remap_ops->supported)
225 		return 0;
226 
227 	return remap_ops->supported();
228 }
229 
230 int __init irq_remapping_prepare(void)
231 {
232 	if (!remap_ops || !remap_ops->prepare)
233 		return -ENODEV;
234 
235 	return remap_ops->prepare();
236 }
237 
238 int __init irq_remapping_enable(void)
239 {
240 	int ret;
241 
242 	if (!remap_ops || !remap_ops->enable)
243 		return -ENODEV;
244 
245 	ret = remap_ops->enable();
246 
247 	if (irq_remapping_enabled)
248 		irq_remapping_modify_x86_ops();
249 
250 	return ret;
251 }
252 
253 void irq_remapping_disable(void)
254 {
255 	if (!irq_remapping_enabled ||
256 	    !remap_ops ||
257 	    !remap_ops->disable)
258 		return;
259 
260 	remap_ops->disable();
261 }
262 
263 int irq_remapping_reenable(int mode)
264 {
265 	if (!irq_remapping_enabled ||
266 	    !remap_ops ||
267 	    !remap_ops->reenable)
268 		return 0;
269 
270 	return remap_ops->reenable(mode);
271 }
272 
273 int __init irq_remap_enable_fault_handling(void)
274 {
275 	if (!irq_remapping_enabled)
276 		return 0;
277 
278 	if (!remap_ops || !remap_ops->enable_faulting)
279 		return -ENODEV;
280 
281 	return remap_ops->enable_faulting();
282 }
283 
284 int setup_ioapic_remapped_entry(int irq,
285 				struct IO_APIC_route_entry *entry,
286 				unsigned int destination, int vector,
287 				struct io_apic_irq_attr *attr)
288 {
289 	if (!remap_ops || !remap_ops->setup_ioapic_entry)
290 		return -ENODEV;
291 
292 	return remap_ops->setup_ioapic_entry(irq, entry, destination,
293 					     vector, attr);
294 }
295 
296 static int set_remapped_irq_affinity(struct irq_data *data,
297 				     const struct cpumask *mask, bool force)
298 {
299 	if (!config_enabled(CONFIG_SMP) || !remap_ops ||
300 	    !remap_ops->set_affinity)
301 		return 0;
302 
303 	return remap_ops->set_affinity(data, mask, force);
304 }
305 
306 void free_remapped_irq(int irq)
307 {
308 	struct irq_cfg *cfg = irq_get_chip_data(irq);
309 
310 	if (!remap_ops || !remap_ops->free_irq)
311 		return;
312 
313 	if (irq_remapped(cfg))
314 		remap_ops->free_irq(irq);
315 }
316 
317 void compose_remapped_msi_msg(struct pci_dev *pdev,
318 			      unsigned int irq, unsigned int dest,
319 			      struct msi_msg *msg, u8 hpet_id)
320 {
321 	struct irq_cfg *cfg = irq_get_chip_data(irq);
322 
323 	if (!irq_remapped(cfg))
324 		native_compose_msi_msg(pdev, irq, dest, msg, hpet_id);
325 	else if (remap_ops && remap_ops->compose_msi_msg)
326 		remap_ops->compose_msi_msg(pdev, irq, dest, msg, hpet_id);
327 }
328 
329 static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec)
330 {
331 	if (!remap_ops || !remap_ops->msi_alloc_irq)
332 		return -ENODEV;
333 
334 	return remap_ops->msi_alloc_irq(pdev, irq, nvec);
335 }
336 
337 static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
338 				  int index, int sub_handle)
339 {
340 	if (!remap_ops || !remap_ops->msi_setup_irq)
341 		return -ENODEV;
342 
343 	return remap_ops->msi_setup_irq(pdev, irq, index, sub_handle);
344 }
345 
346 int setup_hpet_msi_remapped(unsigned int irq, unsigned int id)
347 {
348 	if (!remap_ops || !remap_ops->setup_hpet_msi)
349 		return -ENODEV;
350 
351 	return remap_ops->setup_hpet_msi(irq, id);
352 }
353 
354 void panic_if_irq_remap(const char *msg)
355 {
356 	if (irq_remapping_enabled)
357 		panic(msg);
358 }
359 
360 static void ir_ack_apic_edge(struct irq_data *data)
361 {
362 	ack_APIC_irq();
363 }
364 
365 static void ir_ack_apic_level(struct irq_data *data)
366 {
367 	ack_APIC_irq();
368 	eoi_ioapic_irq(data->irq, data->chip_data);
369 }
370 
371 static void ir_print_prefix(struct irq_data *data, struct seq_file *p)
372 {
373 	seq_printf(p, " IR-%s", data->chip->name);
374 }
375 
376 void irq_remap_modify_chip_defaults(struct irq_chip *chip)
377 {
378 	chip->irq_print_chip = ir_print_prefix;
379 	chip->irq_ack = ir_ack_apic_edge;
380 	chip->irq_eoi = ir_ack_apic_level;
381 	chip->irq_set_affinity = x86_io_apic_ops.set_affinity;
382 }
383 
384 bool setup_remapped_irq(int irq, struct irq_cfg *cfg, struct irq_chip *chip)
385 {
386 	if (!irq_remapped(cfg))
387 		return false;
388 	irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
389 	irq_remap_modify_chip_defaults(chip);
390 	return true;
391 }
392