1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 #include <linux/kernel.h>
4 #include <linux/ioport.h>
5 #include <linux/bitmap.h>
6 #include <linux/pci.h>
7 
8 #include <asm/opal.h>
9 
10 #include "pci.h"
11 
12 /*
13  * The majority of the complexity in supporting SR-IOV on PowerNV comes from
14  * the need to put the MMIO space for each VF into a separate PE. Internally
15  * the PHB maps MMIO addresses to a specific PE using the "Memory BAR Table".
16  * The MBT historically only applied to the 64bit MMIO window of the PHB
17  * so it's common to see it referred to as the "M64BT".
18  *
19  * An MBT entry stores the mapped range as an <base>,<mask> pair. This forces
20  * the address range that we want to map to be power-of-two sized and aligned.
21  * For conventional PCI devices this isn't really an issue since PCI device BARs
22  * have the same requirement.
23  *
24  * For a SR-IOV BAR things are a little more awkward since size and alignment
25  * are not coupled. The alignment is set based on the per-VF BAR size, but
26  * the total BAR area is: number-of-vfs * per-vf-size. The number of VFs
27  * isn't necessarily a power of two, so neither is the total size. To fix that
28  * we need to finesse (read: hack) the Linux BAR allocator so that it will
29  * allocate the SR-IOV BARs in a way that lets us map them using the MBT.
30  *
31  * The changes to size and alignment that we need to do depend on the "mode"
32  * of MBT entry that we use. We only support SR-IOV on PHB3 (IODA2) and above,
33  * so as a baseline we can assume that we have the following BAR modes
34  * available:
35  *
36  *   NB: $PE_COUNT is the number of PEs that the PHB supports.
37  *
38  * a) A segmented BAR that splits the mapped range into $PE_COUNT equally sized
39  *    segments. The n'th segment is mapped to the n'th PE.
40  * b) An un-segmented BAR that maps the whole address range to a specific PE.
41  *
42  *
43  * We prefer to use mode a) since it only requires one MBT entry per SR-IOV BAR
44  * For comparison b) requires one entry per-VF per-BAR, or:
45  * (num-vfs * num-sriov-bars) in total. To use a) we need the size of each segment
46  * to equal the size of the per-VF BAR area. So:
47  *
48  *	new_size = per-vf-size * number-of-PEs
49  *
50  * The alignment for the SR-IOV BAR also needs to be changed from per-vf-size
51  * to "new_size", calculated above. Implementing this is a convoluted process
52  * which requires several hooks in the PCI core:
53  *
54  * 1. In pcibios_device_add() we call pnv_pci_ioda_fixup_iov().
55  *
56  *    At this point the device has been probed and the device's BARs are sized,
57  *    but no resource allocations have been done. The SR-IOV BARs are sized
58  *    based on the maximum number of VFs supported by the device and we need
59  *    to increase that to new_size.
60  *
61  * 2. Later, when Linux actually assigns resources it tries to make the resource
62  *    allocations for each PCI bus as compact as possible. As a part of that it
63  *    sorts the BARs on a bus by their required alignment, which is calculated
64  *    using pci_resource_alignment().
65  *
66  *    For IOV resources this goes:
67  *    pci_resource_alignment()
68  *        pci_sriov_resource_alignment()
69  *            pcibios_sriov_resource_alignment()
70  *                pnv_pci_iov_resource_alignment()
71  *
72  *    Our hook overrides the default alignment, equal to the per-vf-size, with
73  *    new_size computed above.
74  *
75  * 3. When userspace enables VFs for a device:
76  *
77  *    sriov_enable()
78  *       pcibios_sriov_enable()
79  *           pnv_pcibios_sriov_enable()
80  *
81  *    This is where we actually allocate PE numbers for each VF and setup the
82  *    MBT mapping for each SR-IOV BAR. In steps 1) and 2) we setup an "arena"
83  *    where each MBT segment is equal in size to the VF BAR so we can shift
84  *    around the actual SR-IOV BAR location within this arena. We need this
85  *    ability because the PE space is shared by all devices on the same PHB.
86  *    When using mode a) described above segment 0 in maps to PE#0 which might
87  *    be already being used by another device on the PHB.
88  *
89  *    As a result we need allocate a contigious range of PE numbers, then shift
90  *    the address programmed into the SR-IOV BAR of the PF so that the address
91  *    of VF0 matches up with the segment corresponding to the first allocated
92  *    PE number. This is handled in pnv_pci_vf_resource_shift().
93  *
94  *    Once all that is done we return to the PCI core which then enables VFs,
95  *    scans them and creates pci_devs for each. The init process for a VF is
96  *    largely the same as a normal device, but the VF is inserted into the IODA
97  *    PE that we allocated for it rather than the PE associated with the bus.
98  *
99  * 4. When userspace disables VFs we unwind the above in
100  *    pnv_pcibios_sriov_disable(). Fortunately this is relatively simple since
101  *    we don't need to validate anything, just tear down the mappings and
102  *    move SR-IOV resource back to its "proper" location.
103  *
104  * That's how mode a) works. In theory mode b) (single PE mapping) is less work
105  * since we can map each individual VF with a separate BAR. However, there's a
106  * few limitations:
107  *
108  * 1) For IODA2 mode b) has a minimum alignment requirement of 32MB. This makes
109  *    it only usable for devices with very large per-VF BARs. Such devices are
110  *    similar to Big Foot. They definitely exist, but I've never seen one.
111  *
112  * 2) The number of MBT entries that we have is limited. PHB3 and PHB4 only
113  *    16 total and some are needed for. Most SR-IOV capable network cards can support
114  *    more than 16 VFs on each port.
115  *
116  * We use b) when using a) would use more than 1/4 of the entire 64 bit MMIO
117  * window of the PHB.
118  *
119  *
120  *
121  * PHB4 (IODA3) added a few new features that would be useful for SR-IOV. It
122  * allowed the MBT to map 32bit MMIO space in addition to 64bit which allows
123  * us to support SR-IOV BARs in the 32bit MMIO window. This is useful since
124  * the Linux BAR allocation will place any BAR marked as non-prefetchable into
125  * the non-prefetchable bridge window, which is 32bit only. It also added two
126  * new modes:
127  *
128  * c) A segmented BAR similar to a), but each segment can be individually
129  *    mapped to any PE. This is matches how the 32bit MMIO window worked on
130  *    IODA1&2.
131  *
132  * d) A segmented BAR with 8, 64, or 128 segments. This works similarly to a),
133  *    but with fewer segments and configurable base PE.
134  *
135  *    i.e. The n'th segment maps to the (n + base)'th PE.
136  *
137  *    The base PE is also required to be a multiple of the window size.
138  *
139  * Unfortunately, the OPAL API doesn't currently (as of skiboot v6.6) allow us
140  * to exploit any of the IODA3 features.
141  */
142 
pnv_pci_ioda_fixup_iov_resources(struct pci_dev * pdev)143 static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev)
144 {
145 	struct pnv_phb *phb = pci_bus_to_pnvhb(pdev->bus);
146 	struct resource *res;
147 	int i;
148 	resource_size_t vf_bar_sz;
149 	struct pnv_iov_data *iov;
150 	int mul;
151 
152 	iov = kzalloc(sizeof(*iov), GFP_KERNEL);
153 	if (!iov)
154 		goto disable_iov;
155 	pdev->dev.archdata.iov_data = iov;
156 	mul = phb->ioda.total_pe_num;
157 
158 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
159 		res = &pdev->resource[i + PCI_IOV_RESOURCES];
160 		if (!res->flags || res->parent)
161 			continue;
162 		if (!pnv_pci_is_m64_flags(res->flags)) {
163 			dev_warn(&pdev->dev, "Don't support SR-IOV with non M64 VF BAR%d: %pR. \n",
164 				 i, res);
165 			goto disable_iov;
166 		}
167 
168 		vf_bar_sz = pci_iov_resource_size(pdev, i + PCI_IOV_RESOURCES);
169 
170 		/*
171 		 * Generally, one segmented M64 BAR maps one IOV BAR. However,
172 		 * if a VF BAR is too large we end up wasting a lot of space.
173 		 * If each VF needs more than 1/4 of the default m64 segment
174 		 * then each VF BAR should be mapped in single-PE mode to reduce
175 		 * the amount of space required. This does however limit the
176 		 * number of VFs we can support.
177 		 *
178 		 * The 1/4 limit is arbitrary and can be tweaked.
179 		 */
180 		if (vf_bar_sz > (phb->ioda.m64_segsize >> 2)) {
181 			/*
182 			 * On PHB3, the minimum size alignment of M64 BAR in
183 			 * single mode is 32MB. If this VF BAR is smaller than
184 			 * 32MB, but still too large for a segmented window
185 			 * then we can't map it and need to disable SR-IOV for
186 			 * this device.
187 			 */
188 			if (vf_bar_sz < SZ_32M) {
189 				pci_err(pdev, "VF BAR%d: %pR can't be mapped in single PE mode\n",
190 					i, res);
191 				goto disable_iov;
192 			}
193 
194 			iov->m64_single_mode[i] = true;
195 			continue;
196 		}
197 
198 		/*
199 		 * This BAR can be mapped with one segmented window, so adjust
200 		 * te resource size to accommodate.
201 		 */
202 		pci_dbg(pdev, " Fixing VF BAR%d: %pR to\n", i, res);
203 		res->end = res->start + vf_bar_sz * mul - 1;
204 		pci_dbg(pdev, "                       %pR\n", res);
205 
206 		pci_info(pdev, "VF BAR%d: %pR (expanded to %d VFs for PE alignment)",
207 			 i, res, mul);
208 
209 		iov->need_shift = true;
210 	}
211 
212 	return;
213 
214 disable_iov:
215 	/* Save ourselves some MMIO space by disabling the unusable BARs */
216 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
217 		res = &pdev->resource[i + PCI_IOV_RESOURCES];
218 		res->flags = 0;
219 		res->end = res->start - 1;
220 	}
221 
222 	pdev->dev.archdata.iov_data = NULL;
223 	kfree(iov);
224 }
225 
pnv_pci_ioda_fixup_iov(struct pci_dev * pdev)226 void pnv_pci_ioda_fixup_iov(struct pci_dev *pdev)
227 {
228 	if (pdev->is_virtfn) {
229 		struct pnv_ioda_pe *pe = pnv_ioda_get_pe(pdev);
230 
231 		/*
232 		 * VF PEs are single-device PEs so their pdev pointer needs to
233 		 * be set. The pdev doesn't exist when the PE is allocated (in
234 		 * (pcibios_sriov_enable()) so we fix it up here.
235 		 */
236 		pe->pdev = pdev;
237 		WARN_ON(!(pe->flags & PNV_IODA_PE_VF));
238 	} else if (pdev->is_physfn) {
239 		/*
240 		 * For PFs adjust their allocated IOV resources to match what
241 		 * the PHB can support using its M64 BAR table.
242 		 */
243 		pnv_pci_ioda_fixup_iov_resources(pdev);
244 	}
245 }
246 
pnv_pci_iov_resource_alignment(struct pci_dev * pdev,int resno)247 resource_size_t pnv_pci_iov_resource_alignment(struct pci_dev *pdev,
248 						      int resno)
249 {
250 	resource_size_t align = pci_iov_resource_size(pdev, resno);
251 	struct pnv_phb *phb = pci_bus_to_pnvhb(pdev->bus);
252 	struct pnv_iov_data *iov = pnv_iov_get(pdev);
253 
254 	/*
255 	 * iov can be null if we have an SR-IOV device with IOV BAR that can't
256 	 * be placed in the m64 space (i.e. The BAR is 32bit or non-prefetch).
257 	 * In that case we don't allow VFs to be enabled since one of their
258 	 * BARs would not be placed in the correct PE.
259 	 */
260 	if (!iov)
261 		return align;
262 
263 	/*
264 	 * If we're using single mode then we can just use the native VF BAR
265 	 * alignment. We validated that it's possible to use a single PE
266 	 * window above when we did the fixup.
267 	 */
268 	if (iov->m64_single_mode[resno - PCI_IOV_RESOURCES])
269 		return align;
270 
271 	/*
272 	 * On PowerNV platform, IOV BAR is mapped by M64 BAR to enable the
273 	 * SR-IOV. While from hardware perspective, the range mapped by M64
274 	 * BAR should be size aligned.
275 	 *
276 	 * This function returns the total IOV BAR size if M64 BAR is in
277 	 * Shared PE mode or just VF BAR size if not.
278 	 * If the M64 BAR is in Single PE mode, return the VF BAR size or
279 	 * M64 segment size if IOV BAR size is less.
280 	 */
281 	return phb->ioda.total_pe_num * align;
282 }
283 
pnv_pci_vf_release_m64(struct pci_dev * pdev,u16 num_vfs)284 static int pnv_pci_vf_release_m64(struct pci_dev *pdev, u16 num_vfs)
285 {
286 	struct pnv_iov_data   *iov;
287 	struct pnv_phb        *phb;
288 	int window_id;
289 
290 	phb = pci_bus_to_pnvhb(pdev->bus);
291 	iov = pnv_iov_get(pdev);
292 
293 	for_each_set_bit(window_id, iov->used_m64_bar_mask, MAX_M64_BARS) {
294 		opal_pci_phb_mmio_enable(phb->opal_id,
295 					 OPAL_M64_WINDOW_TYPE,
296 					 window_id,
297 					 0);
298 
299 		clear_bit(window_id, &phb->ioda.m64_bar_alloc);
300 	}
301 
302 	return 0;
303 }
304 
305 
306 /*
307  * PHB3 and beyond support segmented windows. The window's address range
308  * is subdivided into phb->ioda.total_pe_num segments and there's a 1-1
309  * mapping between PEs and segments.
310  */
pnv_ioda_map_m64_segmented(struct pnv_phb * phb,int window_id,resource_size_t start,resource_size_t size)311 static int64_t pnv_ioda_map_m64_segmented(struct pnv_phb *phb,
312 					  int window_id,
313 					  resource_size_t start,
314 					  resource_size_t size)
315 {
316 	int64_t rc;
317 
318 	rc = opal_pci_set_phb_mem_window(phb->opal_id,
319 					 OPAL_M64_WINDOW_TYPE,
320 					 window_id,
321 					 start,
322 					 0, /* unused */
323 					 size);
324 	if (rc)
325 		goto out;
326 
327 	rc = opal_pci_phb_mmio_enable(phb->opal_id,
328 				      OPAL_M64_WINDOW_TYPE,
329 				      window_id,
330 				      OPAL_ENABLE_M64_SPLIT);
331 out:
332 	if (rc)
333 		pr_err("Failed to map M64 window #%d: %lld\n", window_id, rc);
334 
335 	return rc;
336 }
337 
pnv_ioda_map_m64_single(struct pnv_phb * phb,int pe_num,int window_id,resource_size_t start,resource_size_t size)338 static int64_t pnv_ioda_map_m64_single(struct pnv_phb *phb,
339 				       int pe_num,
340 				       int window_id,
341 				       resource_size_t start,
342 				       resource_size_t size)
343 {
344 	int64_t rc;
345 
346 	/*
347 	 * The API for setting up m64 mmio windows seems to have been designed
348 	 * with P7-IOC in mind. For that chip each M64 BAR (window) had a fixed
349 	 * split of 8 equally sized segments each of which could individually
350 	 * assigned to a PE.
351 	 *
352 	 * The problem with this is that the API doesn't have any way to
353 	 * communicate the number of segments we want on a BAR. This wasn't
354 	 * a problem for p7-ioc since you didn't have a choice, but the
355 	 * single PE windows added in PHB3 don't map cleanly to this API.
356 	 *
357 	 * As a result we've got this slightly awkward process where we
358 	 * call opal_pci_map_pe_mmio_window() to put the single in single
359 	 * PE mode, and set the PE for the window before setting the address
360 	 * bounds. We need to do it this way because the single PE windows
361 	 * for PHB3 have different alignment requirements on PHB3.
362 	 */
363 	rc = opal_pci_map_pe_mmio_window(phb->opal_id,
364 					 pe_num,
365 					 OPAL_M64_WINDOW_TYPE,
366 					 window_id,
367 					 0);
368 	if (rc)
369 		goto out;
370 
371 	/*
372 	 * NB: In single PE mode the window needs to be aligned to 32MB
373 	 */
374 	rc = opal_pci_set_phb_mem_window(phb->opal_id,
375 					 OPAL_M64_WINDOW_TYPE,
376 					 window_id,
377 					 start,
378 					 0, /* ignored by FW, m64 is 1-1 */
379 					 size);
380 	if (rc)
381 		goto out;
382 
383 	/*
384 	 * Now actually enable it. We specified the BAR should be in "non-split"
385 	 * mode so FW will validate that the BAR is in single PE mode.
386 	 */
387 	rc = opal_pci_phb_mmio_enable(phb->opal_id,
388 				      OPAL_M64_WINDOW_TYPE,
389 				      window_id,
390 				      OPAL_ENABLE_M64_NON_SPLIT);
391 out:
392 	if (rc)
393 		pr_err("Error mapping single PE BAR\n");
394 
395 	return rc;
396 }
397 
pnv_pci_alloc_m64_bar(struct pnv_phb * phb,struct pnv_iov_data * iov)398 static int pnv_pci_alloc_m64_bar(struct pnv_phb *phb, struct pnv_iov_data *iov)
399 {
400 	int win;
401 
402 	do {
403 		win = find_next_zero_bit(&phb->ioda.m64_bar_alloc,
404 				phb->ioda.m64_bar_idx + 1, 0);
405 
406 		if (win >= phb->ioda.m64_bar_idx + 1)
407 			return -1;
408 	} while (test_and_set_bit(win, &phb->ioda.m64_bar_alloc));
409 
410 	set_bit(win, iov->used_m64_bar_mask);
411 
412 	return win;
413 }
414 
pnv_pci_vf_assign_m64(struct pci_dev * pdev,u16 num_vfs)415 static int pnv_pci_vf_assign_m64(struct pci_dev *pdev, u16 num_vfs)
416 {
417 	struct pnv_iov_data   *iov;
418 	struct pnv_phb        *phb;
419 	int                    win;
420 	struct resource       *res;
421 	int                    i, j;
422 	int64_t                rc;
423 	resource_size_t        size, start;
424 	int                    base_pe_num;
425 
426 	phb = pci_bus_to_pnvhb(pdev->bus);
427 	iov = pnv_iov_get(pdev);
428 
429 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
430 		res = &pdev->resource[i + PCI_IOV_RESOURCES];
431 		if (!res->flags || !res->parent)
432 			continue;
433 
434 		/* don't need single mode? map everything in one go! */
435 		if (!iov->m64_single_mode[i]) {
436 			win = pnv_pci_alloc_m64_bar(phb, iov);
437 			if (win < 0)
438 				goto m64_failed;
439 
440 			size = resource_size(res);
441 			start = res->start;
442 
443 			rc = pnv_ioda_map_m64_segmented(phb, win, start, size);
444 			if (rc)
445 				goto m64_failed;
446 
447 			continue;
448 		}
449 
450 		/* otherwise map each VF with single PE BARs */
451 		size = pci_iov_resource_size(pdev, PCI_IOV_RESOURCES + i);
452 		base_pe_num = iov->vf_pe_arr[0].pe_number;
453 
454 		for (j = 0; j < num_vfs; j++) {
455 			win = pnv_pci_alloc_m64_bar(phb, iov);
456 			if (win < 0)
457 				goto m64_failed;
458 
459 			start = res->start + size * j;
460 			rc = pnv_ioda_map_m64_single(phb, win,
461 						     base_pe_num + j,
462 						     start,
463 						     size);
464 			if (rc)
465 				goto m64_failed;
466 		}
467 	}
468 	return 0;
469 
470 m64_failed:
471 	pnv_pci_vf_release_m64(pdev, num_vfs);
472 	return -EBUSY;
473 }
474 
pnv_ioda_release_vf_PE(struct pci_dev * pdev)475 static void pnv_ioda_release_vf_PE(struct pci_dev *pdev)
476 {
477 	struct pnv_phb        *phb;
478 	struct pnv_ioda_pe    *pe, *pe_n;
479 
480 	phb = pci_bus_to_pnvhb(pdev->bus);
481 
482 	if (!pdev->is_physfn)
483 		return;
484 
485 	/* FIXME: Use pnv_ioda_release_pe()? */
486 	list_for_each_entry_safe(pe, pe_n, &phb->ioda.pe_list, list) {
487 		if (pe->parent_dev != pdev)
488 			continue;
489 
490 		pnv_pci_ioda2_release_pe_dma(pe);
491 
492 		/* Remove from list */
493 		mutex_lock(&phb->ioda.pe_list_mutex);
494 		list_del(&pe->list);
495 		mutex_unlock(&phb->ioda.pe_list_mutex);
496 
497 		pnv_ioda_deconfigure_pe(phb, pe);
498 
499 		pnv_ioda_free_pe(pe);
500 	}
501 }
502 
pnv_pci_vf_resource_shift(struct pci_dev * dev,int offset)503 static int pnv_pci_vf_resource_shift(struct pci_dev *dev, int offset)
504 {
505 	struct resource *res, res2;
506 	struct pnv_iov_data *iov;
507 	resource_size_t size;
508 	u16 num_vfs;
509 	int i;
510 
511 	if (!dev->is_physfn)
512 		return -EINVAL;
513 	iov = pnv_iov_get(dev);
514 
515 	/*
516 	 * "offset" is in VFs.  The M64 windows are sized so that when they
517 	 * are segmented, each segment is the same size as the IOV BAR.
518 	 * Each segment is in a separate PE, and the high order bits of the
519 	 * address are the PE number.  Therefore, each VF's BAR is in a
520 	 * separate PE, and changing the IOV BAR start address changes the
521 	 * range of PEs the VFs are in.
522 	 */
523 	num_vfs = iov->num_vfs;
524 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
525 		res = &dev->resource[i + PCI_IOV_RESOURCES];
526 		if (!res->flags || !res->parent)
527 			continue;
528 		if (iov->m64_single_mode[i])
529 			continue;
530 
531 		/*
532 		 * The actual IOV BAR range is determined by the start address
533 		 * and the actual size for num_vfs VFs BAR.  This check is to
534 		 * make sure that after shifting, the range will not overlap
535 		 * with another device.
536 		 */
537 		size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
538 		res2.flags = res->flags;
539 		res2.start = res->start + (size * offset);
540 		res2.end = res2.start + (size * num_vfs) - 1;
541 
542 		if (res2.end > res->end) {
543 			dev_err(&dev->dev, "VF BAR%d: %pR would extend past %pR (trying to enable %d VFs shifted by %d)\n",
544 				i, &res2, res, num_vfs, offset);
545 			return -EBUSY;
546 		}
547 	}
548 
549 	/*
550 	 * Since M64 BAR shares segments among all possible 256 PEs,
551 	 * we have to shift the beginning of PF IOV BAR to make it start from
552 	 * the segment which belongs to the PE number assigned to the first VF.
553 	 * This creates a "hole" in the /proc/iomem which could be used for
554 	 * allocating other resources so we reserve this area below and
555 	 * release when IOV is released.
556 	 */
557 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
558 		res = &dev->resource[i + PCI_IOV_RESOURCES];
559 		if (!res->flags || !res->parent)
560 			continue;
561 		if (iov->m64_single_mode[i])
562 			continue;
563 
564 		size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
565 		res2 = *res;
566 		res->start += size * offset;
567 
568 		dev_info(&dev->dev, "VF BAR%d: %pR shifted to %pR (%sabling %d VFs shifted by %d)\n",
569 			 i, &res2, res, (offset > 0) ? "En" : "Dis",
570 			 num_vfs, offset);
571 
572 		if (offset < 0) {
573 			devm_release_resource(&dev->dev, &iov->holes[i]);
574 			memset(&iov->holes[i], 0, sizeof(iov->holes[i]));
575 		}
576 
577 		pci_update_resource(dev, i + PCI_IOV_RESOURCES);
578 
579 		if (offset > 0) {
580 			iov->holes[i].start = res2.start;
581 			iov->holes[i].end = res2.start + size * offset - 1;
582 			iov->holes[i].flags = IORESOURCE_BUS;
583 			iov->holes[i].name = "pnv_iov_reserved";
584 			devm_request_resource(&dev->dev, res->parent,
585 					&iov->holes[i]);
586 		}
587 	}
588 	return 0;
589 }
590 
pnv_pci_sriov_disable(struct pci_dev * pdev)591 static void pnv_pci_sriov_disable(struct pci_dev *pdev)
592 {
593 	u16                    num_vfs, base_pe;
594 	struct pnv_iov_data   *iov;
595 
596 	iov = pnv_iov_get(pdev);
597 	if (WARN_ON(!iov))
598 		return;
599 
600 	num_vfs = iov->num_vfs;
601 	base_pe = iov->vf_pe_arr[0].pe_number;
602 
603 	/* Release VF PEs */
604 	pnv_ioda_release_vf_PE(pdev);
605 
606 	/* Un-shift the IOV BARs if we need to */
607 	if (iov->need_shift)
608 		pnv_pci_vf_resource_shift(pdev, -base_pe);
609 
610 	/* Release M64 windows */
611 	pnv_pci_vf_release_m64(pdev, num_vfs);
612 }
613 
pnv_ioda_setup_vf_PE(struct pci_dev * pdev,u16 num_vfs)614 static void pnv_ioda_setup_vf_PE(struct pci_dev *pdev, u16 num_vfs)
615 {
616 	struct pnv_phb        *phb;
617 	struct pnv_ioda_pe    *pe;
618 	int                    pe_num;
619 	u16                    vf_index;
620 	struct pnv_iov_data   *iov;
621 	struct pci_dn         *pdn;
622 
623 	if (!pdev->is_physfn)
624 		return;
625 
626 	phb = pci_bus_to_pnvhb(pdev->bus);
627 	pdn = pci_get_pdn(pdev);
628 	iov = pnv_iov_get(pdev);
629 
630 	/* Reserve PE for each VF */
631 	for (vf_index = 0; vf_index < num_vfs; vf_index++) {
632 		int vf_devfn = pci_iov_virtfn_devfn(pdev, vf_index);
633 		int vf_bus = pci_iov_virtfn_bus(pdev, vf_index);
634 		struct pci_dn *vf_pdn;
635 
636 		pe = &iov->vf_pe_arr[vf_index];
637 		pe->phb = phb;
638 		pe->flags = PNV_IODA_PE_VF;
639 		pe->pbus = NULL;
640 		pe->parent_dev = pdev;
641 		pe->mve_number = -1;
642 		pe->rid = (vf_bus << 8) | vf_devfn;
643 
644 		pe_num = pe->pe_number;
645 		pe_info(pe, "VF %04d:%02d:%02d.%d associated with PE#%x\n",
646 			pci_domain_nr(pdev->bus), pdev->bus->number,
647 			PCI_SLOT(vf_devfn), PCI_FUNC(vf_devfn), pe_num);
648 
649 		if (pnv_ioda_configure_pe(phb, pe)) {
650 			/* XXX What do we do here ? */
651 			pnv_ioda_free_pe(pe);
652 			pe->pdev = NULL;
653 			continue;
654 		}
655 
656 		/* Put PE to the list */
657 		mutex_lock(&phb->ioda.pe_list_mutex);
658 		list_add_tail(&pe->list, &phb->ioda.pe_list);
659 		mutex_unlock(&phb->ioda.pe_list_mutex);
660 
661 		/* associate this pe to its pdn */
662 		list_for_each_entry(vf_pdn, &pdn->parent->child_list, list) {
663 			if (vf_pdn->busno == vf_bus &&
664 			    vf_pdn->devfn == vf_devfn) {
665 				vf_pdn->pe_number = pe_num;
666 				break;
667 			}
668 		}
669 
670 		pnv_pci_ioda2_setup_dma_pe(phb, pe);
671 	}
672 }
673 
pnv_pci_sriov_enable(struct pci_dev * pdev,u16 num_vfs)674 static int pnv_pci_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
675 {
676 	struct pnv_ioda_pe    *base_pe;
677 	struct pnv_iov_data   *iov;
678 	struct pnv_phb        *phb;
679 	int                    ret;
680 	u16                    i;
681 
682 	phb = pci_bus_to_pnvhb(pdev->bus);
683 	iov = pnv_iov_get(pdev);
684 
685 	/*
686 	 * There's a calls to IODA2 PE setup code littered throughout. We could
687 	 * probably fix that, but we'd still have problems due to the
688 	 * restriction inherent on IODA1 PHBs.
689 	 *
690 	 * NB: We class IODA3 as IODA2 since they're very similar.
691 	 */
692 	if (phb->type != PNV_PHB_IODA2) {
693 		pci_err(pdev, "SR-IOV is not supported on this PHB\n");
694 		return -ENXIO;
695 	}
696 
697 	if (!iov) {
698 		dev_info(&pdev->dev, "don't support this SRIOV device with non 64bit-prefetchable IOV BAR\n");
699 		return -ENOSPC;
700 	}
701 
702 	/* allocate a contiguous block of PEs for our VFs */
703 	base_pe = pnv_ioda_alloc_pe(phb, num_vfs);
704 	if (!base_pe) {
705 		pci_err(pdev, "Unable to allocate PEs for %d VFs\n", num_vfs);
706 		return -EBUSY;
707 	}
708 
709 	iov->vf_pe_arr = base_pe;
710 	iov->num_vfs = num_vfs;
711 
712 	/* Assign M64 window accordingly */
713 	ret = pnv_pci_vf_assign_m64(pdev, num_vfs);
714 	if (ret) {
715 		dev_info(&pdev->dev, "Not enough M64 window resources\n");
716 		goto m64_failed;
717 	}
718 
719 	/*
720 	 * When using one M64 BAR to map one IOV BAR, we need to shift
721 	 * the IOV BAR according to the PE# allocated to the VFs.
722 	 * Otherwise, the PE# for the VF will conflict with others.
723 	 */
724 	if (iov->need_shift) {
725 		ret = pnv_pci_vf_resource_shift(pdev, base_pe->pe_number);
726 		if (ret)
727 			goto shift_failed;
728 	}
729 
730 	/* Setup VF PEs */
731 	pnv_ioda_setup_vf_PE(pdev, num_vfs);
732 
733 	return 0;
734 
735 shift_failed:
736 	pnv_pci_vf_release_m64(pdev, num_vfs);
737 
738 m64_failed:
739 	for (i = 0; i < num_vfs; i++)
740 		pnv_ioda_free_pe(&iov->vf_pe_arr[i]);
741 
742 	return ret;
743 }
744 
pnv_pcibios_sriov_disable(struct pci_dev * pdev)745 int pnv_pcibios_sriov_disable(struct pci_dev *pdev)
746 {
747 	pnv_pci_sriov_disable(pdev);
748 
749 	/* Release PCI data */
750 	remove_sriov_vf_pdns(pdev);
751 	return 0;
752 }
753 
pnv_pcibios_sriov_enable(struct pci_dev * pdev,u16 num_vfs)754 int pnv_pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
755 {
756 	/* Allocate PCI data */
757 	add_sriov_vf_pdns(pdev);
758 
759 	return pnv_pci_sriov_enable(pdev, num_vfs);
760 }
761