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Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -04001/*
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
13int verbose_request;
14module_param(verbose_request, int, 0644);
15
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -040016static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id);
17
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -040018/* Ensure a device is has the fake IRQ handler "turned on/off" and is
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -040019 * ready to be exported. This MUST be run after xen_pcibk_reset_device
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -040020 * which does the actual PCI device enable/disable.
21 */
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -040022static void xen_pcibk_control_isr(struct pci_dev *dev, int reset)
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -040023{
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -040024 struct xen_pcibk_dev_data *dev_data;
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -040025 int rc;
26 int enable = 0;
27
28 dev_data = pci_get_drvdata(dev);
29 if (!dev_data)
30 return;
31
32 /* We don't deal with bridges */
33 if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
34 return;
35
36 if (reset) {
37 dev_data->enable_intx = 0;
38 dev_data->ack_intr = 0;
39 }
40 enable = dev_data->enable_intx;
41
42 /* Asked to disable, but ISR isn't runnig */
43 if (!enable && !dev_data->isr_on)
44 return;
45
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.
49 */
50 if (enable)
51 dev_data->irq = dev->irq;
52
Konrad Rzeszutek Wilke17ab352011-02-16 15:43:25 -050053 /*
54 * SR-IOV devices in all use MSI-X and have no legacy
55 * interrupts, so inhibit creating a fake IRQ handler for them.
56 */
57 if (dev_data->irq == 0)
58 goto out;
59
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -040060 dev_dbg(&dev->dev, "%s: #%d %s %s%s %s-> %s\n",
61 dev_data->irq_name,
62 dev_data->irq,
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");
68
69 if (enable) {
70 rc = request_irq(dev_data->irq,
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -040071 xen_pcibk_guest_interrupt, IRQF_SHARED,
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -040072 dev_data->irq_name, dev);
73 if (rc) {
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);
77 goto out;
78 }
79 } else {
80 free_irq(dev_data->irq, dev);
81 dev_data->irq = 0;
82 }
83 dev_data->isr_on = enable;
84 dev_data->ack_intr = enable;
85out:
86 dev_dbg(&dev->dev, "%s: #%d %s %s%s %s\n",
87 dev_data->irq_name,
88 dev_data->irq,
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"));
94}
95
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -040096/* Ensure a device is "turned off" and ready to be exported.
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -040097 * (Also see xen_pcibk_config_reset to ensure virtual configuration space is
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -040098 * ready to be re-exported)
99 */
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400100void xen_pcibk_reset_device(struct pci_dev *dev)
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400101{
102 u16 cmd;
103
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400104 xen_pcibk_control_isr(dev, 1 /* reset device */);
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -0400105
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400106 /* Disable devices (but not bridges) */
107 if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
Konrad Rzeszutek Wilka2be65fd2010-03-03 13:38:43 -0500108#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);
115#endif
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400116 pci_disable_device(dev);
117
118 pci_write_config_word(dev, PCI_COMMAND, 0);
119
120 dev->is_busmaster = 0;
121 } else {
122 pci_read_config_word(dev, PCI_COMMAND, &cmd);
123 if (cmd & (PCI_COMMAND_INVALIDATE)) {
124 cmd &= ~(PCI_COMMAND_INVALIDATE);
125 pci_write_config_word(dev, PCI_COMMAND, cmd);
126
127 dev->is_busmaster = 0;
128 }
129 }
130}
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400131
132#ifdef CONFIG_PCI_MSI
133static
134int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev,
135 struct pci_dev *dev, struct xen_pci_op *op)
136{
137 struct xen_pcibk_dev_data *dev_data;
138 int otherend = pdev->xdev->otherend_id;
139 int status;
140
141 if (unlikely(verbose_request))
142 printk(KERN_DEBUG DRV_NAME ": %s: enable MSI\n", pci_name(dev));
143
144 status = pci_enable_msi(dev);
145
146 if (status) {
147 printk(KERN_ERR "error enable msi for guest %x status %x\n",
148 otherend, status);
149 op->value = 0;
150 return XEN_PCI_ERR_op_failed;
151 }
152
153 /* The value the guest needs is actually the IDT vector, not the
154 * the local domain's IRQ number. */
155
156 op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
157 if (unlikely(verbose_request))
158 printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
159 op->value);
160
161 dev_data = pci_get_drvdata(dev);
162 if (dev_data)
163 dev_data->ack_intr = 0;
164
165 return 0;
166}
167
168static
169int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
170 struct pci_dev *dev, struct xen_pci_op *op)
171{
172 struct xen_pcibk_dev_data *dev_data;
173
174 if (unlikely(verbose_request))
175 printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n",
176 pci_name(dev));
177 pci_disable_msi(dev);
178
179 op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
180 if (unlikely(verbose_request))
181 printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
182 op->value);
183 dev_data = pci_get_drvdata(dev);
184 if (dev_data)
185 dev_data->ack_intr = 1;
186 return 0;
187}
188
189static
190int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
191 struct pci_dev *dev, struct xen_pci_op *op)
192{
193 struct xen_pcibk_dev_data *dev_data;
194 int i, result;
195 struct msix_entry *entries;
196
197 if (unlikely(verbose_request))
198 printk(KERN_DEBUG DRV_NAME ": %s: enable MSI-X\n",
199 pci_name(dev));
200 if (op->value > SH_INFO_MAX_VEC)
201 return -EINVAL;
202
203 entries = kmalloc(op->value * sizeof(*entries), GFP_KERNEL);
204 if (entries == NULL)
205 return -ENOMEM;
206
207 for (i = 0; i < op->value; i++) {
208 entries[i].entry = op->msix_entries[i].entry;
209 entries[i].vector = op->msix_entries[i].vector;
210 }
211
212 result = pci_enable_msix(dev, entries, op->value);
213
214 if (result == 0) {
215 for (i = 0; i < op->value; i++) {
216 op->msix_entries[i].entry = entries[i].entry;
217 if (entries[i].vector)
218 op->msix_entries[i].vector =
219 xen_pirq_from_irq(entries[i].vector);
220 if (unlikely(verbose_request))
221 printk(KERN_DEBUG DRV_NAME ": %s: " \
222 "MSI-X[%d]: %d\n",
223 pci_name(dev), i,
224 op->msix_entries[i].vector);
225 }
226 } else {
227 printk(KERN_WARNING DRV_NAME ": %s: failed to enable MSI-X: err %d!\n",
228 pci_name(dev), result);
229 }
230 kfree(entries);
231
232 op->value = result;
233 dev_data = pci_get_drvdata(dev);
234 if (dev_data)
235 dev_data->ack_intr = 0;
236
237 return result;
238}
239
240static
241int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
242 struct pci_dev *dev, struct xen_pci_op *op)
243{
244 struct xen_pcibk_dev_data *dev_data;
245 if (unlikely(verbose_request))
246 printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n",
247 pci_name(dev));
248 pci_disable_msix(dev);
249
250 /*
251 * SR-IOV devices (which don't have any legacy IRQ) have
252 * an undefined IRQ value of zero.
253 */
254 op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
255 if (unlikely(verbose_request))
256 printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n", pci_name(dev),
257 op->value);
258 dev_data = pci_get_drvdata(dev);
259 if (dev_data)
260 dev_data->ack_intr = 1;
261 return 0;
262}
263#endif
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400264/*
265* Now the same evtchn is used for both pcifront conf_read_write request
266* as well as pcie aer front end ack. We use a new work_queue to schedule
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400267* xen_pcibk conf_read_write service for avoiding confict with aer_core
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400268* do_recovery job which also use the system default work_queue
269*/
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400270void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400271{
272 /* Check that frontend is requesting an operation and that we are not
273 * already processing a request */
274 if (test_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags)
275 && !test_and_set_bit(_PDEVF_op_active, &pdev->flags)) {
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400276 queue_work(xen_pcibk_wq, &pdev->op_work);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400277 }
278 /*_XEN_PCIB_active should have been cleared by pcifront. And also make
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400279 sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400280 if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
281 && test_bit(_PCIB_op_pending, &pdev->flags)) {
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400282 wake_up(&xen_pcibk_aer_wait_queue);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400283 }
284}
285
286/* Performing the configuration space reads/writes must not be done in atomic
287 * context because some of the pci_* functions can sleep (mostly due to ACPI
288 * use of semaphores). This function is intended to be called from a work
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400289 * queue in process context taking a struct xen_pcibk_device as a parameter */
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400290
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400291void xen_pcibk_do_op(struct work_struct *data)
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400292{
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400293 struct xen_pcibk_device *pdev =
294 container_of(data, struct xen_pcibk_device, op_work);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400295 struct pci_dev *dev;
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400296 struct xen_pcibk_dev_data *dev_data = NULL;
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400297 struct xen_pci_op *op = &pdev->sh_info->op;
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -0400298 int test_intx = 0;
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400299
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400300 dev = xen_pcibk_get_pci_dev(pdev, op->domain, op->bus, op->devfn);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400301
302 if (dev == NULL)
303 op->err = XEN_PCI_ERR_dev_not_found;
304 else {
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -0400305 dev_data = pci_get_drvdata(dev);
306 if (dev_data)
307 test_intx = dev_data->enable_intx;
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400308 switch (op->cmd) {
309 case XEN_PCI_OP_conf_read:
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400310 op->err = xen_pcibk_config_read(dev,
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400311 op->offset, op->size, &op->value);
312 break;
313 case XEN_PCI_OP_conf_write:
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400314 op->err = xen_pcibk_config_write(dev,
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400315 op->offset, op->size, op->value);
316 break;
317#ifdef CONFIG_PCI_MSI
318 case XEN_PCI_OP_enable_msi:
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400319 op->err = xen_pcibk_enable_msi(pdev, dev, op);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400320 break;
321 case XEN_PCI_OP_disable_msi:
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400322 op->err = xen_pcibk_disable_msi(pdev, dev, op);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400323 break;
324 case XEN_PCI_OP_enable_msix:
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400325 op->err = xen_pcibk_enable_msix(pdev, dev, op);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400326 break;
327 case XEN_PCI_OP_disable_msix:
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400328 op->err = xen_pcibk_disable_msix(pdev, dev, op);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400329 break;
330#endif
331 default:
332 op->err = XEN_PCI_ERR_not_implemented;
333 break;
334 }
335 }
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -0400336 if (!op->err && dev && dev_data) {
337 /* Transition detected */
338 if ((dev_data->enable_intx != test_intx))
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400339 xen_pcibk_control_isr(dev, 0 /* no reset */);
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -0400340 }
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400341 /* Tell the driver domain that we're done. */
342 wmb();
343 clear_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
344 notify_remote_via_irq(pdev->evtchn_irq);
345
346 /* Mark that we're done. */
347 smp_mb__before_clear_bit(); /* /after/ clearing PCIF_active */
348 clear_bit(_PDEVF_op_active, &pdev->flags);
349 smp_mb__after_clear_bit(); /* /before/ final check for work */
350
351 /* Check to see if the driver domain tried to start another request in
352 * between clearing _XEN_PCIF_active and clearing _PDEVF_op_active.
353 */
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400354 xen_pcibk_test_and_schedule_op(pdev);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400355}
356
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400357irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400358{
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400359 struct xen_pcibk_device *pdev = dev_id;
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400360
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400361 xen_pcibk_test_and_schedule_op(pdev);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400362
363 return IRQ_HANDLED;
364}
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400365static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id)
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -0400366{
367 struct pci_dev *dev = (struct pci_dev *)dev_id;
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400368 struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
Konrad Rzeszutek Wilk0513fe92011-07-19 18:56:39 -0400369
370 if (dev_data->isr_on && dev_data->ack_intr) {
371 dev_data->handled++;
372 if ((dev_data->handled % 1000) == 0) {
373 if (xen_test_irq_shared(irq)) {
374 printk(KERN_INFO "%s IRQ line is not shared "
375 "with other domains. Turning ISR off\n",
376 dev_data->irq_name);
377 dev_data->ack_intr = 0;
378 }
379 }
380 return IRQ_HANDLED;
381 }
382 return IRQ_NONE;
383}