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1/*2 * Copyright 2018 Red Hat Inc.3 *4 * Permission is hereby granted, free of charge, to any person obtaining a5 * copy of this software and associated documentation files (the "Software"),6 * to deal in the Software without restriction, including without limitation7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,8 * and/or sell copies of the Software, and to permit persons to whom the9 * Software is furnished to do so, subject to the following conditions:10 *11 * The above copyright notice and this permission notice shall be included in12 * all copies or substantial portions of the Software.13 *14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR20 * OTHER DEALINGS IN THE SOFTWARE.21 */22#include "nouveau_svm.h"23#include "nouveau_drv.h"24#include "nouveau_chan.h"25#include "nouveau_dmem.h"26 27#include <nvif/event.h>28#include <nvif/object.h>29#include <nvif/vmm.h>30 31#include <nvif/class.h>32#include <nvif/clb069.h>33#include <nvif/ifc00d.h>34 35#include <linux/sched/mm.h>36#include <linux/sort.h>37#include <linux/hmm.h>38#include <linux/memremap.h>39#include <linux/rmap.h>40 41struct nouveau_svm {42	struct nouveau_drm *drm;43	struct mutex mutex;44	struct list_head inst;45 46	struct nouveau_svm_fault_buffer {47		int id;48		struct nvif_object object;49		u32 entries;50		u32 getaddr;51		u32 putaddr;52		u32 get;53		u32 put;54		struct nvif_event notify;55		struct work_struct work;56 57		struct nouveau_svm_fault {58			u64 inst;59			u64 addr;60			u64 time;61			u32 engine;62			u8  gpc;63			u8  hub;64			u8  access;65			u8  client;66			u8  fault;67			struct nouveau_svmm *svmm;68		} **fault;69		int fault_nr;70	} buffer[];71};72 73#define FAULT_ACCESS_READ 074#define FAULT_ACCESS_WRITE 175#define FAULT_ACCESS_ATOMIC 276#define FAULT_ACCESS_PREFETCH 377 78#define SVM_DBG(s,f,a...) NV_DEBUG((s)->drm, "svm: "f"\n", ##a)79#define SVM_ERR(s,f,a...) NV_WARN((s)->drm, "svm: "f"\n", ##a)80 81struct nouveau_pfnmap_args {82	struct nvif_ioctl_v0 i;83	struct nvif_ioctl_mthd_v0 m;84	struct nvif_vmm_pfnmap_v0 p;85};86 87struct nouveau_ivmm {88	struct nouveau_svmm *svmm;89	u64 inst;90	struct list_head head;91};92 93static struct nouveau_ivmm *94nouveau_ivmm_find(struct nouveau_svm *svm, u64 inst)95{96	struct nouveau_ivmm *ivmm;97	list_for_each_entry(ivmm, &svm->inst, head) {98		if (ivmm->inst == inst)99			return ivmm;100	}101	return NULL;102}103 104#define SVMM_DBG(s,f,a...)                                                     \105	NV_DEBUG((s)->vmm->cli->drm, "svm-%p: "f"\n", (s), ##a)106#define SVMM_ERR(s,f,a...)                                                     \107	NV_WARN((s)->vmm->cli->drm, "svm-%p: "f"\n", (s), ##a)108 109int110nouveau_svmm_bind(struct drm_device *dev, void *data,111		  struct drm_file *file_priv)112{113	struct nouveau_cli *cli = nouveau_cli(file_priv);114	struct drm_nouveau_svm_bind *args = data;115	unsigned target, cmd;116	unsigned long addr, end;117	struct mm_struct *mm;118 119	args->va_start &= PAGE_MASK;120	args->va_end = ALIGN(args->va_end, PAGE_SIZE);121 122	/* Sanity check arguments */123	if (args->reserved0 || args->reserved1)124		return -EINVAL;125	if (args->header & (~NOUVEAU_SVM_BIND_VALID_MASK))126		return -EINVAL;127	if (args->va_start >= args->va_end)128		return -EINVAL;129 130	cmd = args->header >> NOUVEAU_SVM_BIND_COMMAND_SHIFT;131	cmd &= NOUVEAU_SVM_BIND_COMMAND_MASK;132	switch (cmd) {133	case NOUVEAU_SVM_BIND_COMMAND__MIGRATE:134		break;135	default:136		return -EINVAL;137	}138 139	/* FIXME support CPU target ie all target value < GPU_VRAM */140	target = args->header >> NOUVEAU_SVM_BIND_TARGET_SHIFT;141	target &= NOUVEAU_SVM_BIND_TARGET_MASK;142	switch (target) {143	case NOUVEAU_SVM_BIND_TARGET__GPU_VRAM:144		break;145	default:146		return -EINVAL;147	}148 149	/*150	 * FIXME: For now refuse non 0 stride, we need to change the migrate151	 * kernel function to handle stride to avoid to create a mess within152	 * each device driver.153	 */154	if (args->stride)155		return -EINVAL;156 157	/*158	 * Ok we are ask to do something sane, for now we only support migrate159	 * commands but we will add things like memory policy (what to do on160	 * page fault) and maybe some other commands.161	 */162 163	mm = get_task_mm(current);164	if (!mm) {165		return -EINVAL;166	}167	mmap_read_lock(mm);168 169	if (!cli->svm.svmm) {170		mmap_read_unlock(mm);171		mmput(mm);172		return -EINVAL;173	}174 175	for (addr = args->va_start, end = args->va_end; addr < end;) {176		struct vm_area_struct *vma;177		unsigned long next;178 179		vma = find_vma_intersection(mm, addr, end);180		if (!vma)181			break;182 183		addr = max(addr, vma->vm_start);184		next = min(vma->vm_end, end);185		/* This is a best effort so we ignore errors */186		nouveau_dmem_migrate_vma(cli->drm, cli->svm.svmm, vma, addr,187					 next);188		addr = next;189	}190 191	/*192	 * FIXME Return the number of page we have migrated, again we need to193	 * update the migrate API to return that information so that we can194	 * report it to user space.195	 */196	args->result = 0;197 198	mmap_read_unlock(mm);199	mmput(mm);200 201	return 0;202}203 204/* Unlink channel instance from SVMM. */205void206nouveau_svmm_part(struct nouveau_svmm *svmm, u64 inst)207{208	struct nouveau_ivmm *ivmm;209	if (svmm) {210		mutex_lock(&svmm->vmm->cli->drm->svm->mutex);211		ivmm = nouveau_ivmm_find(svmm->vmm->cli->drm->svm, inst);212		if (ivmm) {213			list_del(&ivmm->head);214			kfree(ivmm);215		}216		mutex_unlock(&svmm->vmm->cli->drm->svm->mutex);217	}218}219 220/* Link channel instance to SVMM. */221int222nouveau_svmm_join(struct nouveau_svmm *svmm, u64 inst)223{224	struct nouveau_ivmm *ivmm;225	if (svmm) {226		if (!(ivmm = kmalloc(sizeof(*ivmm), GFP_KERNEL)))227			return -ENOMEM;228		ivmm->svmm = svmm;229		ivmm->inst = inst;230 231		mutex_lock(&svmm->vmm->cli->drm->svm->mutex);232		list_add(&ivmm->head, &svmm->vmm->cli->drm->svm->inst);233		mutex_unlock(&svmm->vmm->cli->drm->svm->mutex);234	}235	return 0;236}237 238/* Invalidate SVMM address-range on GPU. */239void240nouveau_svmm_invalidate(struct nouveau_svmm *svmm, u64 start, u64 limit)241{242	if (limit > start) {243		nvif_object_mthd(&svmm->vmm->vmm.object, NVIF_VMM_V0_PFNCLR,244				 &(struct nvif_vmm_pfnclr_v0) {245					.addr = start,246					.size = limit - start,247				 }, sizeof(struct nvif_vmm_pfnclr_v0));248	}249}250 251static int252nouveau_svmm_invalidate_range_start(struct mmu_notifier *mn,253				    const struct mmu_notifier_range *update)254{255	struct nouveau_svmm *svmm =256		container_of(mn, struct nouveau_svmm, notifier);257	unsigned long start = update->start;258	unsigned long limit = update->end;259 260	if (!mmu_notifier_range_blockable(update))261		return -EAGAIN;262 263	SVMM_DBG(svmm, "invalidate %016lx-%016lx", start, limit);264 265	mutex_lock(&svmm->mutex);266	if (unlikely(!svmm->vmm))267		goto out;268 269	/*270	 * Ignore invalidation callbacks for device private pages since271	 * the invalidation is handled as part of the migration process.272	 */273	if (update->event == MMU_NOTIFY_MIGRATE &&274	    update->owner == svmm->vmm->cli->drm->dev)275		goto out;276 277	if (limit > svmm->unmanaged.start && start < svmm->unmanaged.limit) {278		if (start < svmm->unmanaged.start) {279			nouveau_svmm_invalidate(svmm, start,280						svmm->unmanaged.limit);281		}282		start = svmm->unmanaged.limit;283	}284 285	nouveau_svmm_invalidate(svmm, start, limit);286 287out:288	mutex_unlock(&svmm->mutex);289	return 0;290}291 292static void nouveau_svmm_free_notifier(struct mmu_notifier *mn)293{294	kfree(container_of(mn, struct nouveau_svmm, notifier));295}296 297static const struct mmu_notifier_ops nouveau_mn_ops = {298	.invalidate_range_start = nouveau_svmm_invalidate_range_start,299	.free_notifier = nouveau_svmm_free_notifier,300};301 302void303nouveau_svmm_fini(struct nouveau_svmm **psvmm)304{305	struct nouveau_svmm *svmm = *psvmm;306	if (svmm) {307		mutex_lock(&svmm->mutex);308		svmm->vmm = NULL;309		mutex_unlock(&svmm->mutex);310		mmu_notifier_put(&svmm->notifier);311		*psvmm = NULL;312	}313}314 315int316nouveau_svmm_init(struct drm_device *dev, void *data,317		  struct drm_file *file_priv)318{319	struct nouveau_cli *cli = nouveau_cli(file_priv);320	struct nouveau_svmm *svmm;321	struct drm_nouveau_svm_init *args = data;322	int ret;323 324	/* We need to fail if svm is disabled */325	if (!cli->drm->svm)326		return -ENOSYS;327 328	/* Allocate tracking for SVM-enabled VMM. */329	if (!(svmm = kzalloc(sizeof(*svmm), GFP_KERNEL)))330		return -ENOMEM;331	svmm->vmm = &cli->svm;332	svmm->unmanaged.start = args->unmanaged_addr;333	svmm->unmanaged.limit = args->unmanaged_addr + args->unmanaged_size;334	mutex_init(&svmm->mutex);335 336	/* Check that SVM isn't already enabled for the client. */337	mutex_lock(&cli->mutex);338	if (cli->svm.cli) {339		ret = -EBUSY;340		goto out_free;341	}342 343	/* Allocate a new GPU VMM that can support SVM (managed by the344	 * client, with replayable faults enabled).345	 *346	 * All future channel/memory allocations will make use of this347	 * VMM instead of the standard one.348	 */349	ret = nvif_vmm_ctor(&cli->mmu, "svmVmm",350			    cli->vmm.vmm.object.oclass, MANAGED,351			    args->unmanaged_addr, args->unmanaged_size,352			    &(struct gp100_vmm_v0) {353				.fault_replay = true,354			    }, sizeof(struct gp100_vmm_v0), &cli->svm.vmm);355	if (ret)356		goto out_free;357 358	mmap_write_lock(current->mm);359	svmm->notifier.ops = &nouveau_mn_ops;360	ret = __mmu_notifier_register(&svmm->notifier, current->mm);361	if (ret)362		goto out_mm_unlock;363	/* Note, ownership of svmm transfers to mmu_notifier */364 365	cli->svm.svmm = svmm;366	cli->svm.cli = cli;367	mmap_write_unlock(current->mm);368	mutex_unlock(&cli->mutex);369	return 0;370 371out_mm_unlock:372	mmap_write_unlock(current->mm);373out_free:374	mutex_unlock(&cli->mutex);375	kfree(svmm);376	return ret;377}378 379/* Issue fault replay for GPU to retry accesses that faulted previously. */380static void381nouveau_svm_fault_replay(struct nouveau_svm *svm)382{383	SVM_DBG(svm, "replay");384	WARN_ON(nvif_object_mthd(&svm->drm->client.vmm.vmm.object,385				 GP100_VMM_VN_FAULT_REPLAY,386				 &(struct gp100_vmm_fault_replay_vn) {},387				 sizeof(struct gp100_vmm_fault_replay_vn)));388}389 390/* Cancel a replayable fault that could not be handled.391 *392 * Cancelling the fault will trigger recovery to reset the engine393 * and kill the offending channel (ie. GPU SIGSEGV).394 */395static void396nouveau_svm_fault_cancel(struct nouveau_svm *svm,397			 u64 inst, u8 hub, u8 gpc, u8 client)398{399	SVM_DBG(svm, "cancel %016llx %d %02x %02x", inst, hub, gpc, client);400	WARN_ON(nvif_object_mthd(&svm->drm->client.vmm.vmm.object,401				 GP100_VMM_VN_FAULT_CANCEL,402				 &(struct gp100_vmm_fault_cancel_v0) {403					.hub = hub,404					.gpc = gpc,405					.client = client,406					.inst = inst,407				 }, sizeof(struct gp100_vmm_fault_cancel_v0)));408}409 410static void411nouveau_svm_fault_cancel_fault(struct nouveau_svm *svm,412			       struct nouveau_svm_fault *fault)413{414	nouveau_svm_fault_cancel(svm, fault->inst,415				      fault->hub,416				      fault->gpc,417				      fault->client);418}419 420static int421nouveau_svm_fault_priority(u8 fault)422{423	switch (fault) {424	case FAULT_ACCESS_PREFETCH:425		return 0;426	case FAULT_ACCESS_READ:427		return 1;428	case FAULT_ACCESS_WRITE:429		return 2;430	case FAULT_ACCESS_ATOMIC:431		return 3;432	default:433		WARN_ON_ONCE(1);434		return -1;435	}436}437 438static int439nouveau_svm_fault_cmp(const void *a, const void *b)440{441	const struct nouveau_svm_fault *fa = *(struct nouveau_svm_fault **)a;442	const struct nouveau_svm_fault *fb = *(struct nouveau_svm_fault **)b;443	int ret;444	if ((ret = (s64)fa->inst - fb->inst))445		return ret;446	if ((ret = (s64)fa->addr - fb->addr))447		return ret;448	return nouveau_svm_fault_priority(fa->access) -449		nouveau_svm_fault_priority(fb->access);450}451 452static void453nouveau_svm_fault_cache(struct nouveau_svm *svm,454			struct nouveau_svm_fault_buffer *buffer, u32 offset)455{456	struct nvif_object *memory = &buffer->object;457	const u32 instlo = nvif_rd32(memory, offset + 0x00);458	const u32 insthi = nvif_rd32(memory, offset + 0x04);459	const u32 addrlo = nvif_rd32(memory, offset + 0x08);460	const u32 addrhi = nvif_rd32(memory, offset + 0x0c);461	const u32 timelo = nvif_rd32(memory, offset + 0x10);462	const u32 timehi = nvif_rd32(memory, offset + 0x14);463	const u32 engine = nvif_rd32(memory, offset + 0x18);464	const u32   info = nvif_rd32(memory, offset + 0x1c);465	const u64   inst = (u64)insthi << 32 | instlo;466	const u8     gpc = (info & 0x1f000000) >> 24;467	const u8     hub = (info & 0x00100000) >> 20;468	const u8  client = (info & 0x00007f00) >> 8;469	struct nouveau_svm_fault *fault;470 471	//XXX: i think we're supposed to spin waiting */472	if (WARN_ON(!(info & 0x80000000)))473		return;474 475	nvif_mask(memory, offset + 0x1c, 0x80000000, 0x00000000);476 477	if (!buffer->fault[buffer->fault_nr]) {478		fault = kmalloc(sizeof(*fault), GFP_KERNEL);479		if (WARN_ON(!fault)) {480			nouveau_svm_fault_cancel(svm, inst, hub, gpc, client);481			return;482		}483		buffer->fault[buffer->fault_nr] = fault;484	}485 486	fault = buffer->fault[buffer->fault_nr++];487	fault->inst   = inst;488	fault->addr   = (u64)addrhi << 32 | addrlo;489	fault->time   = (u64)timehi << 32 | timelo;490	fault->engine = engine;491	fault->gpc    = gpc;492	fault->hub    = hub;493	fault->access = (info & 0x000f0000) >> 16;494	fault->client = client;495	fault->fault  = (info & 0x0000001f);496 497	SVM_DBG(svm, "fault %016llx %016llx %02x",498		fault->inst, fault->addr, fault->access);499}500 501struct svm_notifier {502	struct mmu_interval_notifier notifier;503	struct nouveau_svmm *svmm;504};505 506static bool nouveau_svm_range_invalidate(struct mmu_interval_notifier *mni,507					 const struct mmu_notifier_range *range,508					 unsigned long cur_seq)509{510	struct svm_notifier *sn =511		container_of(mni, struct svm_notifier, notifier);512 513	if (range->event == MMU_NOTIFY_EXCLUSIVE &&514	    range->owner == sn->svmm->vmm->cli->drm->dev)515		return true;516 517	/*518	 * serializes the update to mni->invalidate_seq done by caller and519	 * prevents invalidation of the PTE from progressing while HW is being520	 * programmed. This is very hacky and only works because the normal521	 * notifier that does invalidation is always called after the range522	 * notifier.523	 */524	if (mmu_notifier_range_blockable(range))525		mutex_lock(&sn->svmm->mutex);526	else if (!mutex_trylock(&sn->svmm->mutex))527		return false;528	mmu_interval_set_seq(mni, cur_seq);529	mutex_unlock(&sn->svmm->mutex);530	return true;531}532 533static const struct mmu_interval_notifier_ops nouveau_svm_mni_ops = {534	.invalidate = nouveau_svm_range_invalidate,535};536 537static void nouveau_hmm_convert_pfn(struct nouveau_drm *drm,538				    struct hmm_range *range,539				    struct nouveau_pfnmap_args *args)540{541	struct page *page;542 543	/*544	 * The address prepared here is passed through nvif_object_ioctl()545	 * to an eventual DMA map in something like gp100_vmm_pgt_pfn()546	 *547	 * This is all just encoding the internal hmm representation into a548	 * different nouveau internal representation.549	 */550	if (!(range->hmm_pfns[0] & HMM_PFN_VALID)) {551		args->p.phys[0] = 0;552		return;553	}554 555	page = hmm_pfn_to_page(range->hmm_pfns[0]);556	/*557	 * Only map compound pages to the GPU if the CPU is also mapping the558	 * page as a compound page. Otherwise, the PTE protections might not be559	 * consistent (e.g., CPU only maps part of a compound page).560	 * Note that the underlying page might still be larger than the561	 * CPU mapping (e.g., a PUD sized compound page partially mapped with562	 * a PMD sized page table entry).563	 */564	if (hmm_pfn_to_map_order(range->hmm_pfns[0])) {565		unsigned long addr = args->p.addr;566 567		args->p.page = hmm_pfn_to_map_order(range->hmm_pfns[0]) +568				PAGE_SHIFT;569		args->p.size = 1UL << args->p.page;570		args->p.addr &= ~(args->p.size - 1);571		page -= (addr - args->p.addr) >> PAGE_SHIFT;572	}573	if (is_device_private_page(page))574		args->p.phys[0] = nouveau_dmem_page_addr(page) |575				NVIF_VMM_PFNMAP_V0_V |576				NVIF_VMM_PFNMAP_V0_VRAM;577	else578		args->p.phys[0] = page_to_phys(page) |579				NVIF_VMM_PFNMAP_V0_V |580				NVIF_VMM_PFNMAP_V0_HOST;581	if (range->hmm_pfns[0] & HMM_PFN_WRITE)582		args->p.phys[0] |= NVIF_VMM_PFNMAP_V0_W;583}584 585static int nouveau_atomic_range_fault(struct nouveau_svmm *svmm,586			       struct nouveau_drm *drm,587			       struct nouveau_pfnmap_args *args, u32 size,588			       struct svm_notifier *notifier)589{590	unsigned long timeout =591		jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);592	struct mm_struct *mm = svmm->notifier.mm;593	struct page *page;594	unsigned long start = args->p.addr;595	unsigned long notifier_seq;596	int ret = 0;597 598	ret = mmu_interval_notifier_insert(&notifier->notifier, mm,599					args->p.addr, args->p.size,600					&nouveau_svm_mni_ops);601	if (ret)602		return ret;603 604	while (true) {605		if (time_after(jiffies, timeout)) {606			ret = -EBUSY;607			goto out;608		}609 610		notifier_seq = mmu_interval_read_begin(&notifier->notifier);611		mmap_read_lock(mm);612		ret = make_device_exclusive_range(mm, start, start + PAGE_SIZE,613					    &page, drm->dev);614		mmap_read_unlock(mm);615		if (ret <= 0 || !page) {616			ret = -EINVAL;617			goto out;618		}619 620		mutex_lock(&svmm->mutex);621		if (!mmu_interval_read_retry(&notifier->notifier,622					     notifier_seq))623			break;624		mutex_unlock(&svmm->mutex);625	}626 627	/* Map the page on the GPU. */628	args->p.page = 12;629	args->p.size = PAGE_SIZE;630	args->p.addr = start;631	args->p.phys[0] = page_to_phys(page) |632		NVIF_VMM_PFNMAP_V0_V |633		NVIF_VMM_PFNMAP_V0_W |634		NVIF_VMM_PFNMAP_V0_A |635		NVIF_VMM_PFNMAP_V0_HOST;636 637	ret = nvif_object_ioctl(&svmm->vmm->vmm.object, args, size, NULL);638	mutex_unlock(&svmm->mutex);639 640	unlock_page(page);641	put_page(page);642 643out:644	mmu_interval_notifier_remove(&notifier->notifier);645	return ret;646}647 648static int nouveau_range_fault(struct nouveau_svmm *svmm,649			       struct nouveau_drm *drm,650			       struct nouveau_pfnmap_args *args, u32 size,651			       unsigned long hmm_flags,652			       struct svm_notifier *notifier)653{654	unsigned long timeout =655		jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);656	/* Have HMM fault pages within the fault window to the GPU. */657	unsigned long hmm_pfns[1];658	struct hmm_range range = {659		.notifier = &notifier->notifier,660		.default_flags = hmm_flags,661		.hmm_pfns = hmm_pfns,662		.dev_private_owner = drm->dev,663	};664	struct mm_struct *mm = svmm->notifier.mm;665	int ret;666 667	ret = mmu_interval_notifier_insert(&notifier->notifier, mm,668					args->p.addr, args->p.size,669					&nouveau_svm_mni_ops);670	if (ret)671		return ret;672 673	range.start = notifier->notifier.interval_tree.start;674	range.end = notifier->notifier.interval_tree.last + 1;675 676	while (true) {677		if (time_after(jiffies, timeout)) {678			ret = -EBUSY;679			goto out;680		}681 682		range.notifier_seq = mmu_interval_read_begin(range.notifier);683		mmap_read_lock(mm);684		ret = hmm_range_fault(&range);685		mmap_read_unlock(mm);686		if (ret) {687			if (ret == -EBUSY)688				continue;689			goto out;690		}691 692		mutex_lock(&svmm->mutex);693		if (mmu_interval_read_retry(range.notifier,694					    range.notifier_seq)) {695			mutex_unlock(&svmm->mutex);696			continue;697		}698		break;699	}700 701	nouveau_hmm_convert_pfn(drm, &range, args);702 703	ret = nvif_object_ioctl(&svmm->vmm->vmm.object, args, size, NULL);704	mutex_unlock(&svmm->mutex);705 706out:707	mmu_interval_notifier_remove(&notifier->notifier);708 709	return ret;710}711 712static void713nouveau_svm_fault(struct work_struct *work)714{715	struct nouveau_svm_fault_buffer *buffer = container_of(work, typeof(*buffer), work);716	struct nouveau_svm *svm = container_of(buffer, typeof(*svm), buffer[buffer->id]);717	struct nvif_object *device = &svm->drm->client.device.object;718	struct nouveau_svmm *svmm;719	struct {720		struct nouveau_pfnmap_args i;721		u64 phys[1];722	} args;723	unsigned long hmm_flags;724	u64 inst, start, limit;725	int fi, fn;726	int replay = 0, atomic = 0, ret;727 728	/* Parse available fault buffer entries into a cache, and update729	 * the GET pointer so HW can reuse the entries.730	 */731	SVM_DBG(svm, "fault handler");732	if (buffer->get == buffer->put) {733		buffer->put = nvif_rd32(device, buffer->putaddr);734		buffer->get = nvif_rd32(device, buffer->getaddr);735		if (buffer->get == buffer->put)736			return;737	}738	buffer->fault_nr = 0;739 740	SVM_DBG(svm, "get %08x put %08x", buffer->get, buffer->put);741	while (buffer->get != buffer->put) {742		nouveau_svm_fault_cache(svm, buffer, buffer->get * 0x20);743		if (++buffer->get == buffer->entries)744			buffer->get = 0;745	}746	nvif_wr32(device, buffer->getaddr, buffer->get);747	SVM_DBG(svm, "%d fault(s) pending", buffer->fault_nr);748 749	/* Sort parsed faults by instance pointer to prevent unnecessary750	 * instance to SVMM translations, followed by address and access751	 * type to reduce the amount of work when handling the faults.752	 */753	sort(buffer->fault, buffer->fault_nr, sizeof(*buffer->fault),754	     nouveau_svm_fault_cmp, NULL);755 756	/* Lookup SVMM structure for each unique instance pointer. */757	mutex_lock(&svm->mutex);758	for (fi = 0, svmm = NULL; fi < buffer->fault_nr; fi++) {759		if (!svmm || buffer->fault[fi]->inst != inst) {760			struct nouveau_ivmm *ivmm =761				nouveau_ivmm_find(svm, buffer->fault[fi]->inst);762			svmm = ivmm ? ivmm->svmm : NULL;763			inst = buffer->fault[fi]->inst;764			SVM_DBG(svm, "inst %016llx -> svm-%p", inst, svmm);765		}766		buffer->fault[fi]->svmm = svmm;767	}768	mutex_unlock(&svm->mutex);769 770	/* Process list of faults. */771	args.i.i.version = 0;772	args.i.i.type = NVIF_IOCTL_V0_MTHD;773	args.i.m.version = 0;774	args.i.m.method = NVIF_VMM_V0_PFNMAP;775	args.i.p.version = 0;776 777	for (fi = 0; fn = fi + 1, fi < buffer->fault_nr; fi = fn) {778		struct svm_notifier notifier;779		struct mm_struct *mm;780 781		/* Cancel any faults from non-SVM channels. */782		if (!(svmm = buffer->fault[fi]->svmm)) {783			nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);784			continue;785		}786		SVMM_DBG(svmm, "addr %016llx", buffer->fault[fi]->addr);787 788		/* We try and group handling of faults within a small789		 * window into a single update.790		 */791		start = buffer->fault[fi]->addr;792		limit = start + PAGE_SIZE;793		if (start < svmm->unmanaged.limit)794			limit = min_t(u64, limit, svmm->unmanaged.start);795 796		/*797		 * Prepare the GPU-side update of all pages within the798		 * fault window, determining required pages and access799		 * permissions based on pending faults.800		 */801		args.i.p.addr = start;802		args.i.p.page = PAGE_SHIFT;803		args.i.p.size = PAGE_SIZE;804		/*805		 * Determine required permissions based on GPU fault806		 * access flags.807		 */808		switch (buffer->fault[fi]->access) {809		case 0: /* READ. */810			hmm_flags = HMM_PFN_REQ_FAULT;811			break;812		case 2: /* ATOMIC. */813			atomic = true;814			break;815		case 3: /* PREFETCH. */816			hmm_flags = 0;817			break;818		default:819			hmm_flags = HMM_PFN_REQ_FAULT | HMM_PFN_REQ_WRITE;820			break;821		}822 823		mm = svmm->notifier.mm;824		if (!mmget_not_zero(mm)) {825			nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);826			continue;827		}828 829		notifier.svmm = svmm;830		if (atomic)831			ret = nouveau_atomic_range_fault(svmm, svm->drm,832							 &args.i, sizeof(args),833							 &notifier);834		else835			ret = nouveau_range_fault(svmm, svm->drm, &args.i,836						  sizeof(args), hmm_flags,837						  &notifier);838		mmput(mm);839 840		limit = args.i.p.addr + args.i.p.size;841		for (fn = fi; ++fn < buffer->fault_nr; ) {842			/* It's okay to skip over duplicate addresses from the843			 * same SVMM as faults are ordered by access type such844			 * that only the first one needs to be handled.845			 *846			 * ie. WRITE faults appear first, thus any handling of847			 * pending READ faults will already be satisfied.848			 * But if a large page is mapped, make sure subsequent849			 * fault addresses have sufficient access permission.850			 */851			if (buffer->fault[fn]->svmm != svmm ||852			    buffer->fault[fn]->addr >= limit ||853			    (buffer->fault[fi]->access == FAULT_ACCESS_READ &&854			     !(args.phys[0] & NVIF_VMM_PFNMAP_V0_V)) ||855			    (buffer->fault[fi]->access != FAULT_ACCESS_READ &&856			     buffer->fault[fi]->access != FAULT_ACCESS_PREFETCH &&857			     !(args.phys[0] & NVIF_VMM_PFNMAP_V0_W)) ||858			    (buffer->fault[fi]->access != FAULT_ACCESS_READ &&859			     buffer->fault[fi]->access != FAULT_ACCESS_WRITE &&860			     buffer->fault[fi]->access != FAULT_ACCESS_PREFETCH &&861			     !(args.phys[0] & NVIF_VMM_PFNMAP_V0_A)))862				break;863		}864 865		/* If handling failed completely, cancel all faults. */866		if (ret) {867			while (fi < fn) {868				struct nouveau_svm_fault *fault =869					buffer->fault[fi++];870 871				nouveau_svm_fault_cancel_fault(svm, fault);872			}873		} else874			replay++;875	}876 877	/* Issue fault replay to the GPU. */878	if (replay)879		nouveau_svm_fault_replay(svm);880}881 882static int883nouveau_svm_event(struct nvif_event *event, void *argv, u32 argc)884{885	struct nouveau_svm_fault_buffer *buffer = container_of(event, typeof(*buffer), notify);886 887	schedule_work(&buffer->work);888	return NVIF_EVENT_KEEP;889}890 891static struct nouveau_pfnmap_args *892nouveau_pfns_to_args(void *pfns)893{894	return container_of(pfns, struct nouveau_pfnmap_args, p.phys);895}896 897u64 *898nouveau_pfns_alloc(unsigned long npages)899{900	struct nouveau_pfnmap_args *args;901 902	args = kzalloc(struct_size(args, p.phys, npages), GFP_KERNEL);903	if (!args)904		return NULL;905 906	args->i.type = NVIF_IOCTL_V0_MTHD;907	args->m.method = NVIF_VMM_V0_PFNMAP;908	args->p.page = PAGE_SHIFT;909 910	return args->p.phys;911}912 913void914nouveau_pfns_free(u64 *pfns)915{916	struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns);917 918	kfree(args);919}920 921void922nouveau_pfns_map(struct nouveau_svmm *svmm, struct mm_struct *mm,923		 unsigned long addr, u64 *pfns, unsigned long npages)924{925	struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns);926 927	args->p.addr = addr;928	args->p.size = npages << PAGE_SHIFT;929 930	mutex_lock(&svmm->mutex);931 932	nvif_object_ioctl(&svmm->vmm->vmm.object, args,933			  struct_size(args, p.phys, npages), NULL);934 935	mutex_unlock(&svmm->mutex);936}937 938static void939nouveau_svm_fault_buffer_fini(struct nouveau_svm *svm, int id)940{941	struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];942 943	nvif_event_block(&buffer->notify);944	flush_work(&buffer->work);945}946 947static int948nouveau_svm_fault_buffer_init(struct nouveau_svm *svm, int id)949{950	struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];951	struct nvif_object *device = &svm->drm->client.device.object;952 953	buffer->get = nvif_rd32(device, buffer->getaddr);954	buffer->put = nvif_rd32(device, buffer->putaddr);955	SVM_DBG(svm, "get %08x put %08x (init)", buffer->get, buffer->put);956 957	return nvif_event_allow(&buffer->notify);958}959 960static void961nouveau_svm_fault_buffer_dtor(struct nouveau_svm *svm, int id)962{963	struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];964	int i;965 966	if (!nvif_object_constructed(&buffer->object))967		return;968 969	nouveau_svm_fault_buffer_fini(svm, id);970 971	if (buffer->fault) {972		for (i = 0; buffer->fault[i] && i < buffer->entries; i++)973			kfree(buffer->fault[i]);974		kvfree(buffer->fault);975	}976 977	nvif_event_dtor(&buffer->notify);978	nvif_object_dtor(&buffer->object);979}980 981static int982nouveau_svm_fault_buffer_ctor(struct nouveau_svm *svm, s32 oclass, int id)983{984	struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];985	struct nouveau_drm *drm = svm->drm;986	struct nvif_object *device = &drm->client.device.object;987	struct nvif_clb069_v0 args = {};988	int ret;989 990	buffer->id = id;991 992	ret = nvif_object_ctor(device, "svmFaultBuffer", 0, oclass, &args,993			       sizeof(args), &buffer->object);994	if (ret < 0) {995		SVM_ERR(svm, "Fault buffer allocation failed: %d", ret);996		return ret;997	}998 999	nvif_object_map(&buffer->object, NULL, 0);1000	buffer->entries = args.entries;1001	buffer->getaddr = args.get;1002	buffer->putaddr = args.put;1003	INIT_WORK(&buffer->work, nouveau_svm_fault);1004 1005	ret = nvif_event_ctor(&buffer->object, "svmFault", id, nouveau_svm_event, true, NULL, 0,1006			      &buffer->notify);1007	if (ret)1008		return ret;1009 1010	buffer->fault = kvcalloc(buffer->entries, sizeof(*buffer->fault), GFP_KERNEL);1011	if (!buffer->fault)1012		return -ENOMEM;1013 1014	return nouveau_svm_fault_buffer_init(svm, id);1015}1016 1017void1018nouveau_svm_resume(struct nouveau_drm *drm)1019{1020	struct nouveau_svm *svm = drm->svm;1021	if (svm)1022		nouveau_svm_fault_buffer_init(svm, 0);1023}1024 1025void1026nouveau_svm_suspend(struct nouveau_drm *drm)1027{1028	struct nouveau_svm *svm = drm->svm;1029	if (svm)1030		nouveau_svm_fault_buffer_fini(svm, 0);1031}1032 1033void1034nouveau_svm_fini(struct nouveau_drm *drm)1035{1036	struct nouveau_svm *svm = drm->svm;1037	if (svm) {1038		nouveau_svm_fault_buffer_dtor(svm, 0);1039		kfree(drm->svm);1040		drm->svm = NULL;1041	}1042}1043 1044void1045nouveau_svm_init(struct nouveau_drm *drm)1046{1047	static const struct nvif_mclass buffers[] = {1048		{   VOLTA_FAULT_BUFFER_A, 0 },1049		{ MAXWELL_FAULT_BUFFER_A, 0 },1050		{}1051	};1052	struct nouveau_svm *svm;1053	int ret;1054 1055	/* Disable on Volta and newer until channel recovery is fixed,1056	 * otherwise clients will have a trivial way to trash the GPU1057	 * for everyone.1058	 */1059	if (drm->client.device.info.family > NV_DEVICE_INFO_V0_PASCAL)1060		return;1061 1062	drm->svm = svm = kzalloc(struct_size(drm->svm, buffer, 1), GFP_KERNEL);1063	if (!drm->svm)1064		return;1065 1066	drm->svm->drm = drm;1067	mutex_init(&drm->svm->mutex);1068	INIT_LIST_HEAD(&drm->svm->inst);1069 1070	ret = nvif_mclass(&drm->client.device.object, buffers);1071	if (ret < 0) {1072		SVM_DBG(svm, "No supported fault buffer class");1073		nouveau_svm_fini(drm);1074		return;1075	}1076 1077	ret = nouveau_svm_fault_buffer_ctor(svm, buffers[ret].oclass, 0);1078	if (ret) {1079		nouveau_svm_fini(drm);1080		return;1081	}1082 1083	SVM_DBG(svm, "Initialised");1084}1085