2 * PCI Backend Operations - respond to PCI requests from Frontend
4 * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
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>
14 module_param(verbose_request, int, 0644);
16 static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id);
18 /* Ensure a device is has the fake IRQ handler "turned on/off" and is
19 * ready to be exported. This MUST be run after xen_pcibk_reset_device
20 * which does the actual PCI device enable/disable.
22 static void xen_pcibk_control_isr(struct pci_dev *dev, int reset)
24 struct xen_pcibk_dev_data *dev_data;
28 dev_data = pci_get_drvdata(dev);
32 /* We don't deal with bridges */
33 if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
37 dev_data->enable_intx = 0;
38 dev_data->ack_intr = 0;
40 enable = dev_data->enable_intx;
42 /* Asked to disable, but ISR isn't runnig */
43 if (!enable && !dev_data->isr_on)
46 /* Squirrel away the IRQs in the dev_data. We need this
47 * b/c when device transitions to MSI, the dev->irq is
48 * overwritten with the MSI vector.
51 dev_data->irq = dev->irq;
54 * SR-IOV devices in all use MSI-X and have no legacy
55 * interrupts, so inhibit creating a fake IRQ handler for them.
57 if (dev_data->irq == 0)
60 dev_dbg(&dev->dev, "%s: #%d %s %s%s %s-> %s\n",
63 pci_is_enabled(dev) ? "on" : "off",
64 dev->msi_enabled ? "MSI" : "",
65 dev->msix_enabled ? "MSI/X" : "",
66 dev_data->isr_on ? "enable" : "disable",
67 enable ? "enable" : "disable");
70 rc = request_irq(dev_data->irq,
71 xen_pcibk_guest_interrupt, IRQF_SHARED,
72 dev_data->irq_name, dev);
74 dev_err(&dev->dev, "%s: failed to install fake IRQ " \
75 "handler for IRQ %d! (rc:%d)\n",
76 dev_data->irq_name, dev_data->irq, rc);
80 free_irq(dev_data->irq, dev);
83 dev_data->isr_on = enable;
84 dev_data->ack_intr = enable;
86 dev_dbg(&dev->dev, "%s: #%d %s %s%s %s\n",
89 pci_is_enabled(dev) ? "on" : "off",
90 dev->msi_enabled ? "MSI" : "",
91 dev->msix_enabled ? "MSI/X" : "",
92 enable ? (dev_data->isr_on ? "enabled" : "failed to enable") :
93 (dev_data->isr_on ? "failed to disable" : "disabled"));
96 /* Ensure a device is "turned off" and ready to be exported.
97 * (Also see xen_pcibk_config_reset to ensure virtual configuration space is
98 * ready to be re-exported)
100 void xen_pcibk_reset_device(struct pci_dev *dev)
104 xen_pcibk_control_isr(dev, 1 /* reset device */);
106 /* Disable devices (but not bridges) */
107 if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
108 #ifdef CONFIG_PCI_MSI
109 /* The guest could have been abruptly killed without
110 * disabling MSI/MSI-X interrupts.*/
111 if (dev->msix_enabled)
112 pci_disable_msix(dev);
113 if (dev->msi_enabled)
114 pci_disable_msi(dev);
116 if (pci_is_enabled(dev))
117 pci_disable_device(dev);
119 pci_write_config_word(dev, PCI_COMMAND, 0);
121 dev->is_busmaster = 0;
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);
128 dev->is_busmaster = 0;
133 #ifdef CONFIG_PCI_MSI
135 int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev,
136 struct pci_dev *dev, struct xen_pci_op *op)
138 struct xen_pcibk_dev_data *dev_data;
141 if (unlikely(verbose_request))
142 printk(KERN_DEBUG DRV_NAME ": %s: enable MSI\n", pci_name(dev));
144 status = pci_enable_msi(dev);
147 pr_warn_ratelimited(DRV_NAME ": %s: error enabling MSI for guest %u: err %d\n",
148 pci_name(dev), pdev->xdev->otherend_id,
151 return XEN_PCI_ERR_op_failed;
154 /* The value the guest needs is actually the IDT vector, not the
155 * the local domain's IRQ number. */
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),
162 dev_data = pci_get_drvdata(dev);
164 dev_data->ack_intr = 0;
170 int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
171 struct pci_dev *dev, struct xen_pci_op *op)
173 struct xen_pcibk_dev_data *dev_data;
175 if (unlikely(verbose_request))
176 printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n",
178 pci_disable_msi(dev);
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),
184 dev_data = pci_get_drvdata(dev);
186 dev_data->ack_intr = 1;
191 int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
192 struct pci_dev *dev, struct xen_pci_op *op)
194 struct xen_pcibk_dev_data *dev_data;
196 struct msix_entry *entries;
198 if (unlikely(verbose_request))
199 printk(KERN_DEBUG DRV_NAME ": %s: enable MSI-X\n",
201 if (op->value > SH_INFO_MAX_VEC)
204 entries = kmalloc(op->value * sizeof(*entries), GFP_KERNEL);
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;
213 result = pci_enable_msix(dev, entries, op->value);
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: " \
225 op->msix_entries[i].vector);
228 pr_warn_ratelimited(DRV_NAME ": %s: error enabling MSI-X for guest %u: err %d!\n",
229 pci_name(dev), pdev->xdev->otherend_id,
234 dev_data = pci_get_drvdata(dev);
236 dev_data->ack_intr = 0;
238 return result > 0 ? 0 : result;
242 int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
243 struct pci_dev *dev, struct xen_pci_op *op)
245 struct xen_pcibk_dev_data *dev_data;
246 if (unlikely(verbose_request))
247 printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n",
249 pci_disable_msix(dev);
252 * SR-IOV devices (which don't have any legacy IRQ) have
253 * an undefined IRQ value of zero.
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),
259 dev_data = pci_get_drvdata(dev);
261 dev_data->ack_intr = 1;
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
271 void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
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);
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);
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 */
292 void xen_pcibk_do_op(struct work_struct *data)
294 struct xen_pcibk_device *pdev =
295 container_of(data, struct xen_pcibk_device, op_work);
297 struct xen_pcibk_dev_data *dev_data = NULL;
298 struct xen_pci_op *op = &pdev->sh_info->op;
301 dev = xen_pcibk_get_pci_dev(pdev, op->domain, op->bus, op->devfn);
304 op->err = XEN_PCI_ERR_dev_not_found;
306 dev_data = pci_get_drvdata(dev);
308 test_intx = dev_data->enable_intx;
310 case XEN_PCI_OP_conf_read:
311 op->err = xen_pcibk_config_read(dev,
312 op->offset, op->size, &op->value);
314 case XEN_PCI_OP_conf_write:
315 op->err = xen_pcibk_config_write(dev,
316 op->offset, op->size, op->value);
318 #ifdef CONFIG_PCI_MSI
319 case XEN_PCI_OP_enable_msi:
320 op->err = xen_pcibk_enable_msi(pdev, dev, op);
322 case XEN_PCI_OP_disable_msi:
323 op->err = xen_pcibk_disable_msi(pdev, dev, op);
325 case XEN_PCI_OP_enable_msix:
326 op->err = xen_pcibk_enable_msix(pdev, dev, op);
328 case XEN_PCI_OP_disable_msix:
329 op->err = xen_pcibk_disable_msix(pdev, dev, op);
333 op->err = XEN_PCI_ERR_not_implemented;
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 */);
342 /* Tell the driver domain that we're done. */
344 clear_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
345 notify_remote_via_irq(pdev->evtchn_irq);
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 */
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.
355 xen_pcibk_test_and_schedule_op(pdev);
358 irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
360 struct xen_pcibk_device *pdev = dev_id;
362 xen_pcibk_test_and_schedule_op(pdev);
366 static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id)
368 struct pci_dev *dev = (struct pci_dev *)dev_id;
369 struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
371 if (dev_data->isr_on && dev_data->ack_intr) {
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",
378 dev_data->ack_intr = 0;