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1/*
2 * PCI Backend Operations - respond to PCI requests from Frontend
3 *
4 * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
5 */
6#include <linux/module.h>
7#include <linux/wait.h>
8#include <linux/bitops.h>
9#include <xen/events.h>
10#include <linux/sched.h>
11#include "pciback.h"
12
13#define DRV_NAME "xen-pciback"
14int verbose_request;
15module_param(verbose_request, int, 0644);
16
17static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id);
18
19/* Ensure a device is has the fake IRQ handler "turned on/off" and is
20 * ready to be exported. This MUST be run after xen_pcibk_reset_device
21 * which does the actual PCI device enable/disable.
22 */
23static void xen_pcibk_control_isr(struct pci_dev *dev, int reset)
24{
25 struct xen_pcibk_dev_data *dev_data;
26 int rc;
27 int enable = 0;
28
29 dev_data = pci_get_drvdata(dev);
30 if (!dev_data)
31 return;
32
33 /* We don't deal with bridges */
34 if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
35 return;
36
37 if (reset) {
38 dev_data->enable_intx = 0;
39 dev_data->ack_intr = 0;
40 }
41 enable = dev_data->enable_intx;
42
43 /* Asked to disable, but ISR isn't runnig */
44 if (!enable && !dev_data->isr_on)
45 return;
46
47 /* Squirrel away the IRQs in the dev_data. We need this
48 * b/c when device transitions to MSI, the dev->irq is
49 * overwritten with the MSI vector.
50 */
51 if (enable)
52 dev_data->irq = dev->irq;
53
54 /*
55 * SR-IOV devices in all use MSI-X and have no legacy
56 * interrupts, so inhibit creating a fake IRQ handler for them.
57 */
58 if (dev_data->irq == 0)
59 goto out;
60
61 dev_dbg(&dev->dev, "%s: #%d %s %s%s %s-> %s\n",
62 dev_data->irq_name,
63 dev_data->irq,
64 pci_is_enabled(dev) ? "on" : "off",
65 dev->msi_enabled ? "MSI" : "",
66 dev->msix_enabled ? "MSI/X" : "",
67 dev_data->isr_on ? "enable" : "disable",
68 enable ? "enable" : "disable");
69
70 if (enable) {
71 rc = request_irq(dev_data->irq,
72 xen_pcibk_guest_interrupt, IRQF_SHARED,
73 dev_data->irq_name, dev);
74 if (rc) {
75 dev_err(&dev->dev, "%s: failed to install fake IRQ " \
76 "handler for IRQ %d! (rc:%d)\n",
77 dev_data->irq_name, dev_data->irq, rc);
78 goto out;
79 }
80 } else {
81 free_irq(dev_data->irq, dev);
82 dev_data->irq = 0;
83 }
84 dev_data->isr_on = enable;
85 dev_data->ack_intr = enable;
86out:
87 dev_dbg(&dev->dev, "%s: #%d %s %s%s %s\n",
88 dev_data->irq_name,
89 dev_data->irq,
90 pci_is_enabled(dev) ? "on" : "off",
91 dev->msi_enabled ? "MSI" : "",
92 dev->msix_enabled ? "MSI/X" : "",
93 enable ? (dev_data->isr_on ? "enabled" : "failed to enable") :
94 (dev_data->isr_on ? "failed to disable" : "disabled"));
95}
96
97/* Ensure a device is "turned off" and ready to be exported.
98 * (Also see xen_pcibk_config_reset to ensure virtual configuration space is
99 * ready to be re-exported)
100 */
101void xen_pcibk_reset_device(struct pci_dev *dev)
102{
103 u16 cmd;
104
105 xen_pcibk_control_isr(dev, 1 /* reset device */);
106
107 /* Disable devices (but not bridges) */
108 if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
109#ifdef CONFIG_PCI_MSI
110 /* The guest could have been abruptly killed without
111 * disabling MSI/MSI-X interrupts.*/
112 if (dev->msix_enabled)
113 pci_disable_msix(dev);
114 if (dev->msi_enabled)
115 pci_disable_msi(dev);
116#endif
117 pci_disable_device(dev);
118
119 pci_write_config_word(dev, PCI_COMMAND, 0);
120
121 dev->is_busmaster = 0;
122 } else {
123 pci_read_config_word(dev, PCI_COMMAND, &cmd);
124 if (cmd & (PCI_COMMAND_INVALIDATE)) {
125 cmd &= ~(PCI_COMMAND_INVALIDATE);
126 pci_write_config_word(dev, PCI_COMMAND, cmd);
127
128 dev->is_busmaster = 0;
129 }
130 }
131}
132
133#ifdef CONFIG_PCI_MSI
134static
135int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev,
136 struct pci_dev *dev, struct xen_pci_op *op)
137{
138 struct xen_pcibk_dev_data *dev_data;
139 int otherend = pdev->xdev->otherend_id;
140 int status;
141
142 if (unlikely(verbose_request))
143 printk(KERN_DEBUG DRV_NAME ": %s: enable MSI\n", pci_name(dev));
144
145 status = pci_enable_msi(dev);
146
147 if (status) {
148 printk(KERN_ERR "error enable msi for guest %x status %x\n",
149 otherend, status);
150 op->value = 0;
151 return XEN_PCI_ERR_op_failed;
152 }
153
154 /* The value the guest needs is actually the IDT vector, not the
155 * the local domain's IRQ number. */
156
157 op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
158 if (unlikely(verbose_request))
159 printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
160 op->value);
161
162 dev_data = pci_get_drvdata(dev);
163 if (dev_data)
164 dev_data->ack_intr = 0;
165
166 return 0;
167}
168
169static
170int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
171 struct pci_dev *dev, struct xen_pci_op *op)
172{
173 struct xen_pcibk_dev_data *dev_data;
174
175 if (unlikely(verbose_request))
176 printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n",
177 pci_name(dev));
178 pci_disable_msi(dev);
179
180 op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
181 if (unlikely(verbose_request))
182 printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
183 op->value);
184 dev_data = pci_get_drvdata(dev);
185 if (dev_data)
186 dev_data->ack_intr = 1;
187 return 0;
188}
189
190static
191int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
192 struct pci_dev *dev, struct xen_pci_op *op)
193{
194 struct xen_pcibk_dev_data *dev_data;
195 int i, result;
196 struct msix_entry *entries;
197
198 if (unlikely(verbose_request))
199 printk(KERN_DEBUG DRV_NAME ": %s: enable MSI-X\n",
200 pci_name(dev));
201 if (op->value > SH_INFO_MAX_VEC)
202 return -EINVAL;
203
204 entries = kmalloc(op->value * sizeof(*entries), GFP_KERNEL);
205 if (entries == NULL)
206 return -ENOMEM;
207
208 for (i = 0; i < op->value; i++) {
209 entries[i].entry = op->msix_entries[i].entry;
210 entries[i].vector = op->msix_entries[i].vector;
211 }
212
213 result = pci_enable_msix(dev, entries, op->value);
214
215 if (result == 0) {
216 for (i = 0; i < op->value; i++) {
217 op->msix_entries[i].entry = entries[i].entry;
218 if (entries[i].vector)
219 op->msix_entries[i].vector =
220 xen_pirq_from_irq(entries[i].vector);
221 if (unlikely(verbose_request))
222 printk(KERN_DEBUG DRV_NAME ": %s: " \
223 "MSI-X[%d]: %d\n",
224 pci_name(dev), i,
225 op->msix_entries[i].vector);
226 }
227 } else {
228 printk(KERN_WARNING DRV_NAME ": %s: failed to enable MSI-X: err %d!\n",
229 pci_name(dev), result);
230 }
231 kfree(entries);
232
233 op->value = result;
234 dev_data = pci_get_drvdata(dev);
235 if (dev_data)
236 dev_data->ack_intr = 0;
237
238 return result;
239}
240
241static
242int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
243 struct pci_dev *dev, struct xen_pci_op *op)
244{
245 struct xen_pcibk_dev_data *dev_data;
246 if (unlikely(verbose_request))
247 printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n",
248 pci_name(dev));
249 pci_disable_msix(dev);
250
251 /*
252 * SR-IOV devices (which don't have any legacy IRQ) have
253 * an undefined IRQ value of zero.
254 */
255 op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
256 if (unlikely(verbose_request))
257 printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n", pci_name(dev),
258 op->value);
259 dev_data = pci_get_drvdata(dev);
260 if (dev_data)
261 dev_data->ack_intr = 1;
262 return 0;
263}
264#endif
265/*
266* Now the same evtchn is used for both pcifront conf_read_write request
267* as well as pcie aer front end ack. We use a new work_queue to schedule
268* xen_pcibk conf_read_write service for avoiding confict with aer_core
269* do_recovery job which also use the system default work_queue
270*/
271void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
272{
273 /* Check that frontend is requesting an operation and that we are not
274 * already processing a request */
275 if (test_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags)
276 && !test_and_set_bit(_PDEVF_op_active, &pdev->flags)) {
277 queue_work(xen_pcibk_wq, &pdev->op_work);
278 }
279 /*_XEN_PCIB_active should have been cleared by pcifront. And also make
280 sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
281 if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
282 && test_bit(_PCIB_op_pending, &pdev->flags)) {
283 wake_up(&xen_pcibk_aer_wait_queue);
284 }
285}
286
287/* Performing the configuration space reads/writes must not be done in atomic
288 * context because some of the pci_* functions can sleep (mostly due to ACPI
289 * use of semaphores). This function is intended to be called from a work
290 * queue in process context taking a struct xen_pcibk_device as a parameter */
291
292void xen_pcibk_do_op(struct work_struct *data)
293{
294 struct xen_pcibk_device *pdev =
295 container_of(data, struct xen_pcibk_device, op_work);
296 struct pci_dev *dev;
297 struct xen_pcibk_dev_data *dev_data = NULL;
298 struct xen_pci_op *op = &pdev->sh_info->op;
299 int test_intx = 0;
300
301 dev = xen_pcibk_get_pci_dev(pdev, op->domain, op->bus, op->devfn);
302
303 if (dev == NULL)
304 op->err = XEN_PCI_ERR_dev_not_found;
305 else {
306 dev_data = pci_get_drvdata(dev);
307 if (dev_data)
308 test_intx = dev_data->enable_intx;
309 switch (op->cmd) {
310 case XEN_PCI_OP_conf_read:
311 op->err = xen_pcibk_config_read(dev,
312 op->offset, op->size, &op->value);
313 break;
314 case XEN_PCI_OP_conf_write:
315 op->err = xen_pcibk_config_write(dev,
316 op->offset, op->size, op->value);
317 break;
318#ifdef CONFIG_PCI_MSI
319 case XEN_PCI_OP_enable_msi:
320 op->err = xen_pcibk_enable_msi(pdev, dev, op);
321 break;
322 case XEN_PCI_OP_disable_msi:
323 op->err = xen_pcibk_disable_msi(pdev, dev, op);
324 break;
325 case XEN_PCI_OP_enable_msix:
326 op->err = xen_pcibk_enable_msix(pdev, dev, op);
327 break;
328 case XEN_PCI_OP_disable_msix:
329 op->err = xen_pcibk_disable_msix(pdev, dev, op);
330 break;
331#endif
332 default:
333 op->err = XEN_PCI_ERR_not_implemented;
334 break;
335 }
336 }
337 if (!op->err && dev && dev_data) {
338 /* Transition detected */
339 if ((dev_data->enable_intx != test_intx))
340 xen_pcibk_control_isr(dev, 0 /* no reset */);
341 }
342 /* Tell the driver domain that we're done. */
343 wmb();
344 clear_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
345 notify_remote_via_irq(pdev->evtchn_irq);
346
347 /* Mark that we're done. */
348 smp_mb__before_clear_bit(); /* /after/ clearing PCIF_active */
349 clear_bit(_PDEVF_op_active, &pdev->flags);
350 smp_mb__after_clear_bit(); /* /before/ final check for work */
351
352 /* Check to see if the driver domain tried to start another request in
353 * between clearing _XEN_PCIF_active and clearing _PDEVF_op_active.
354 */
355 xen_pcibk_test_and_schedule_op(pdev);
356}
357
358irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
359{
360 struct xen_pcibk_device *pdev = dev_id;
361
362 xen_pcibk_test_and_schedule_op(pdev);
363
364 return IRQ_HANDLED;
365}
366static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id)
367{
368 struct pci_dev *dev = (struct pci_dev *)dev_id;
369 struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
370
371 if (dev_data->isr_on && dev_data->ack_intr) {
372 dev_data->handled++;
373 if ((dev_data->handled % 1000) == 0) {
374 if (xen_test_irq_shared(irq)) {
375 printk(KERN_INFO "%s IRQ line is not shared "
376 "with other domains. Turning ISR off\n",
377 dev_data->irq_name);
378 dev_data->ack_intr = 0;
379 }
380 }
381 return IRQ_HANDLED;
382 }
383 return IRQ_NONE;
384}
1/*
2 * PCI Backend Operations - respond to PCI requests from Frontend
3 *
4 * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
5 */
6
7#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8
9#include <linux/moduleparam.h>
10#include <linux/wait.h>
11#include <linux/bitops.h>
12#include <xen/events.h>
13#include <linux/sched.h>
14#include "pciback.h"
15
16int verbose_request;
17module_param(verbose_request, int, 0644);
18
19static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id);
20
21/* Ensure a device is has the fake IRQ handler "turned on/off" and is
22 * ready to be exported. This MUST be run after xen_pcibk_reset_device
23 * which does the actual PCI device enable/disable.
24 */
25static void xen_pcibk_control_isr(struct pci_dev *dev, int reset)
26{
27 struct xen_pcibk_dev_data *dev_data;
28 int rc;
29 int enable = 0;
30
31 dev_data = pci_get_drvdata(dev);
32 if (!dev_data)
33 return;
34
35 /* We don't deal with bridges */
36 if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
37 return;
38
39 if (reset) {
40 dev_data->enable_intx = 0;
41 dev_data->ack_intr = 0;
42 }
43 enable = dev_data->enable_intx;
44
45 /* Asked to disable, but ISR isn't runnig */
46 if (!enable && !dev_data->isr_on)
47 return;
48
49 /* Squirrel away the IRQs in the dev_data. We need this
50 * b/c when device transitions to MSI, the dev->irq is
51 * overwritten with the MSI vector.
52 */
53 if (enable)
54 dev_data->irq = dev->irq;
55
56 /*
57 * SR-IOV devices in all use MSI-X and have no legacy
58 * interrupts, so inhibit creating a fake IRQ handler for them.
59 */
60 if (dev_data->irq == 0)
61 goto out;
62
63 dev_dbg(&dev->dev, "%s: #%d %s %s%s %s-> %s\n",
64 dev_data->irq_name,
65 dev_data->irq,
66 pci_is_enabled(dev) ? "on" : "off",
67 dev->msi_enabled ? "MSI" : "",
68 dev->msix_enabled ? "MSI/X" : "",
69 dev_data->isr_on ? "enable" : "disable",
70 enable ? "enable" : "disable");
71
72 if (enable) {
73 /*
74 * The MSI or MSI-X should not have an IRQ handler. Otherwise
75 * if the guest terminates we BUG_ON in free_msi_irqs.
76 */
77 if (dev->msi_enabled || dev->msix_enabled)
78 goto out;
79
80 rc = request_irq(dev_data->irq,
81 xen_pcibk_guest_interrupt, IRQF_SHARED,
82 dev_data->irq_name, dev);
83 if (rc) {
84 dev_err(&dev->dev, "%s: failed to install fake IRQ " \
85 "handler for IRQ %d! (rc:%d)\n",
86 dev_data->irq_name, dev_data->irq, rc);
87 goto out;
88 }
89 } else {
90 free_irq(dev_data->irq, dev);
91 dev_data->irq = 0;
92 }
93 dev_data->isr_on = enable;
94 dev_data->ack_intr = enable;
95out:
96 dev_dbg(&dev->dev, "%s: #%d %s %s%s %s\n",
97 dev_data->irq_name,
98 dev_data->irq,
99 pci_is_enabled(dev) ? "on" : "off",
100 dev->msi_enabled ? "MSI" : "",
101 dev->msix_enabled ? "MSI/X" : "",
102 enable ? (dev_data->isr_on ? "enabled" : "failed to enable") :
103 (dev_data->isr_on ? "failed to disable" : "disabled"));
104}
105
106/* Ensure a device is "turned off" and ready to be exported.
107 * (Also see xen_pcibk_config_reset to ensure virtual configuration space is
108 * ready to be re-exported)
109 */
110void xen_pcibk_reset_device(struct pci_dev *dev)
111{
112 u16 cmd;
113
114 xen_pcibk_control_isr(dev, 1 /* reset device */);
115
116 /* Disable devices (but not bridges) */
117 if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
118#ifdef CONFIG_PCI_MSI
119 /* The guest could have been abruptly killed without
120 * disabling MSI/MSI-X interrupts.*/
121 if (dev->msix_enabled)
122 pci_disable_msix(dev);
123 if (dev->msi_enabled)
124 pci_disable_msi(dev);
125#endif
126 if (pci_is_enabled(dev))
127 pci_disable_device(dev);
128
129 pci_write_config_word(dev, PCI_COMMAND, 0);
130
131 dev->is_busmaster = 0;
132 } else {
133 pci_read_config_word(dev, PCI_COMMAND, &cmd);
134 if (cmd & (PCI_COMMAND_INVALIDATE)) {
135 cmd &= ~(PCI_COMMAND_INVALIDATE);
136 pci_write_config_word(dev, PCI_COMMAND, cmd);
137
138 dev->is_busmaster = 0;
139 }
140 }
141}
142
143#ifdef CONFIG_PCI_MSI
144static
145int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev,
146 struct pci_dev *dev, struct xen_pci_op *op)
147{
148 struct xen_pcibk_dev_data *dev_data;
149 int status;
150
151 if (unlikely(verbose_request))
152 printk(KERN_DEBUG DRV_NAME ": %s: enable MSI\n", pci_name(dev));
153
154 if (dev->msi_enabled)
155 status = -EALREADY;
156 else if (dev->msix_enabled)
157 status = -ENXIO;
158 else
159 status = pci_enable_msi(dev);
160
161 if (status) {
162 pr_warn_ratelimited("%s: error enabling MSI for guest %u: err %d\n",
163 pci_name(dev), pdev->xdev->otherend_id,
164 status);
165 op->value = 0;
166 return XEN_PCI_ERR_op_failed;
167 }
168
169 /* The value the guest needs is actually the IDT vector, not the
170 * the local domain's IRQ number. */
171
172 op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
173 if (unlikely(verbose_request))
174 printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
175 op->value);
176
177 dev_data = pci_get_drvdata(dev);
178 if (dev_data)
179 dev_data->ack_intr = 0;
180
181 return 0;
182}
183
184static
185int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
186 struct pci_dev *dev, struct xen_pci_op *op)
187{
188 if (unlikely(verbose_request))
189 printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n",
190 pci_name(dev));
191
192 if (dev->msi_enabled) {
193 struct xen_pcibk_dev_data *dev_data;
194
195 pci_disable_msi(dev);
196
197 dev_data = pci_get_drvdata(dev);
198 if (dev_data)
199 dev_data->ack_intr = 1;
200 }
201 op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
202 if (unlikely(verbose_request))
203 printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
204 op->value);
205 return 0;
206}
207
208static
209int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
210 struct pci_dev *dev, struct xen_pci_op *op)
211{
212 struct xen_pcibk_dev_data *dev_data;
213 int i, result;
214 struct msix_entry *entries;
215 u16 cmd;
216
217 if (unlikely(verbose_request))
218 printk(KERN_DEBUG DRV_NAME ": %s: enable MSI-X\n",
219 pci_name(dev));
220
221 if (op->value > SH_INFO_MAX_VEC)
222 return -EINVAL;
223
224 if (dev->msix_enabled)
225 return -EALREADY;
226
227 /*
228 * PCI_COMMAND_MEMORY must be enabled, otherwise we may not be able
229 * to access the BARs where the MSI-X entries reside.
230 * But VF devices are unique in which the PF needs to be checked.
231 */
232 pci_read_config_word(pci_physfn(dev), PCI_COMMAND, &cmd);
233 if (dev->msi_enabled || !(cmd & PCI_COMMAND_MEMORY))
234 return -ENXIO;
235
236 entries = kmalloc(op->value * sizeof(*entries), GFP_KERNEL);
237 if (entries == NULL)
238 return -ENOMEM;
239
240 for (i = 0; i < op->value; i++) {
241 entries[i].entry = op->msix_entries[i].entry;
242 entries[i].vector = op->msix_entries[i].vector;
243 }
244
245 result = pci_enable_msix_exact(dev, entries, op->value);
246 if (result == 0) {
247 for (i = 0; i < op->value; i++) {
248 op->msix_entries[i].entry = entries[i].entry;
249 if (entries[i].vector) {
250 op->msix_entries[i].vector =
251 xen_pirq_from_irq(entries[i].vector);
252 if (unlikely(verbose_request))
253 printk(KERN_DEBUG DRV_NAME ": %s: " \
254 "MSI-X[%d]: %d\n",
255 pci_name(dev), i,
256 op->msix_entries[i].vector);
257 }
258 }
259 } else
260 pr_warn_ratelimited("%s: error enabling MSI-X for guest %u: err %d!\n",
261 pci_name(dev), pdev->xdev->otherend_id,
262 result);
263 kfree(entries);
264
265 op->value = result;
266 dev_data = pci_get_drvdata(dev);
267 if (dev_data)
268 dev_data->ack_intr = 0;
269
270 return result > 0 ? 0 : result;
271}
272
273static
274int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
275 struct pci_dev *dev, struct xen_pci_op *op)
276{
277 if (unlikely(verbose_request))
278 printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n",
279 pci_name(dev));
280
281 if (dev->msix_enabled) {
282 struct xen_pcibk_dev_data *dev_data;
283
284 pci_disable_msix(dev);
285
286 dev_data = pci_get_drvdata(dev);
287 if (dev_data)
288 dev_data->ack_intr = 1;
289 }
290 /*
291 * SR-IOV devices (which don't have any legacy IRQ) have
292 * an undefined IRQ value of zero.
293 */
294 op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
295 if (unlikely(verbose_request))
296 printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n",
297 pci_name(dev), op->value);
298 return 0;
299}
300#endif
301/*
302* Now the same evtchn is used for both pcifront conf_read_write request
303* as well as pcie aer front end ack. We use a new work_queue to schedule
304* xen_pcibk conf_read_write service for avoiding confict with aer_core
305* do_recovery job which also use the system default work_queue
306*/
307void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
308{
309 /* Check that frontend is requesting an operation and that we are not
310 * already processing a request */
311 if (test_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags)
312 && !test_and_set_bit(_PDEVF_op_active, &pdev->flags)) {
313 schedule_work(&pdev->op_work);
314 }
315 /*_XEN_PCIB_active should have been cleared by pcifront. And also make
316 sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
317 if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
318 && test_bit(_PCIB_op_pending, &pdev->flags)) {
319 wake_up(&xen_pcibk_aer_wait_queue);
320 }
321}
322
323/* Performing the configuration space reads/writes must not be done in atomic
324 * context because some of the pci_* functions can sleep (mostly due to ACPI
325 * use of semaphores). This function is intended to be called from a work
326 * queue in process context taking a struct xen_pcibk_device as a parameter */
327
328void xen_pcibk_do_op(struct work_struct *data)
329{
330 struct xen_pcibk_device *pdev =
331 container_of(data, struct xen_pcibk_device, op_work);
332 struct pci_dev *dev;
333 struct xen_pcibk_dev_data *dev_data = NULL;
334 struct xen_pci_op *op = &pdev->op;
335 int test_intx = 0;
336#ifdef CONFIG_PCI_MSI
337 unsigned int nr = 0;
338#endif
339
340 *op = pdev->sh_info->op;
341 barrier();
342 dev = xen_pcibk_get_pci_dev(pdev, op->domain, op->bus, op->devfn);
343
344 if (dev == NULL)
345 op->err = XEN_PCI_ERR_dev_not_found;
346 else {
347 dev_data = pci_get_drvdata(dev);
348 if (dev_data)
349 test_intx = dev_data->enable_intx;
350 switch (op->cmd) {
351 case XEN_PCI_OP_conf_read:
352 op->err = xen_pcibk_config_read(dev,
353 op->offset, op->size, &op->value);
354 break;
355 case XEN_PCI_OP_conf_write:
356 op->err = xen_pcibk_config_write(dev,
357 op->offset, op->size, op->value);
358 break;
359#ifdef CONFIG_PCI_MSI
360 case XEN_PCI_OP_enable_msi:
361 op->err = xen_pcibk_enable_msi(pdev, dev, op);
362 break;
363 case XEN_PCI_OP_disable_msi:
364 op->err = xen_pcibk_disable_msi(pdev, dev, op);
365 break;
366 case XEN_PCI_OP_enable_msix:
367 nr = op->value;
368 op->err = xen_pcibk_enable_msix(pdev, dev, op);
369 break;
370 case XEN_PCI_OP_disable_msix:
371 op->err = xen_pcibk_disable_msix(pdev, dev, op);
372 break;
373#endif
374 default:
375 op->err = XEN_PCI_ERR_not_implemented;
376 break;
377 }
378 }
379 if (!op->err && dev && dev_data) {
380 /* Transition detected */
381 if ((dev_data->enable_intx != test_intx))
382 xen_pcibk_control_isr(dev, 0 /* no reset */);
383 }
384 pdev->sh_info->op.err = op->err;
385 pdev->sh_info->op.value = op->value;
386#ifdef CONFIG_PCI_MSI
387 if (op->cmd == XEN_PCI_OP_enable_msix && op->err == 0) {
388 unsigned int i;
389
390 for (i = 0; i < nr; i++)
391 pdev->sh_info->op.msix_entries[i].vector =
392 op->msix_entries[i].vector;
393 }
394#endif
395 /* Tell the driver domain that we're done. */
396 wmb();
397 clear_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
398 notify_remote_via_irq(pdev->evtchn_irq);
399
400 /* Mark that we're done. */
401 smp_mb__before_atomic(); /* /after/ clearing PCIF_active */
402 clear_bit(_PDEVF_op_active, &pdev->flags);
403 smp_mb__after_atomic(); /* /before/ final check for work */
404
405 /* Check to see if the driver domain tried to start another request in
406 * between clearing _XEN_PCIF_active and clearing _PDEVF_op_active.
407 */
408 xen_pcibk_test_and_schedule_op(pdev);
409}
410
411irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
412{
413 struct xen_pcibk_device *pdev = dev_id;
414
415 xen_pcibk_test_and_schedule_op(pdev);
416
417 return IRQ_HANDLED;
418}
419static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id)
420{
421 struct pci_dev *dev = (struct pci_dev *)dev_id;
422 struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
423
424 if (dev_data->isr_on && dev_data->ack_intr) {
425 dev_data->handled++;
426 if ((dev_data->handled % 1000) == 0) {
427 if (xen_test_irq_shared(irq)) {
428 pr_info("%s IRQ line is not shared "
429 "with other domains. Turning ISR off\n",
430 dev_data->irq_name);
431 dev_data->ack_intr = 0;
432 }
433 }
434 return IRQ_HANDLED;
435 }
436 return IRQ_NONE;
437}