Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 704 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
new file mode 100644
index 000000000..b7eae3aee
--- /dev/null
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
@@ -0,0 +1,704 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2014-2016 Intel Corporation
+ */
+
+#include <linux/pagevec.h>
+#include <linux/shmem_fs.h>
+#include <linux/swap.h>
+
+#include <drm/drm_cache.h>
+
+#include "gem/i915_gem_region.h"
+#include "i915_drv.h"
+#include "i915_gem_object.h"
+#include "i915_gem_tiling.h"
+#include "i915_gemfs.h"
+#include "i915_scatterlist.h"
+#include "i915_trace.h"
+
+/*
+ * Move pages to appropriate lru and release the pagevec, decrementing the
+ * ref count of those pages.
+ */
+static void check_release_pagevec(struct pagevec *pvec)
+{
+	check_move_unevictable_pages(pvec);
+	__pagevec_release(pvec);
+	cond_resched();
+}
+
+void shmem_sg_free_table(struct sg_table *st, struct address_space *mapping,
+			 bool dirty, bool backup)
+{
+	struct sgt_iter sgt_iter;
+	struct pagevec pvec;
+	struct page *page;
+
+	mapping_clear_unevictable(mapping);
+
+	pagevec_init(&pvec);
+	for_each_sgt_page(page, sgt_iter, st) {
+		if (dirty)
+			set_page_dirty(page);
+
+		if (backup)
+			mark_page_accessed(page);
+
+		if (!pagevec_add(&pvec, page))
+			check_release_pagevec(&pvec);
+	}
+	if (pagevec_count(&pvec))
+		check_release_pagevec(&pvec);
+
+	sg_free_table(st);
+}
+
+int shmem_sg_alloc_table(struct drm_i915_private *i915, struct sg_table *st,
+			 size_t size, struct intel_memory_region *mr,
+			 struct address_space *mapping,
+			 unsigned int max_segment)
+{
+	const unsigned long page_count = size / PAGE_SIZE;
+	unsigned long i;
+	struct scatterlist *sg;
+	struct page *page;
+	unsigned long last_pfn = 0;	/* suppress gcc warning */
+	gfp_t noreclaim;
+	int ret;
+
+	/*
+	 * If there's no chance of allocating enough pages for the whole
+	 * object, bail early.
+	 */
+	if (size > resource_size(&mr->region))
+		return -ENOMEM;
+
+	if (sg_alloc_table(st, page_count, GFP_KERNEL | __GFP_NOWARN))
+		return -ENOMEM;
+
+	/*
+	 * Get the list of pages out of our struct file.  They'll be pinned
+	 * at this point until we release them.
+	 *
+	 * Fail silently without starting the shrinker
+	 */
+	mapping_set_unevictable(mapping);
+	noreclaim = mapping_gfp_constraint(mapping, ~__GFP_RECLAIM);
+	noreclaim |= __GFP_NORETRY | __GFP_NOWARN;
+
+	sg = st->sgl;
+	st->nents = 0;
+	for (i = 0; i < page_count; i++) {
+		const unsigned int shrink[] = {
+			I915_SHRINK_BOUND | I915_SHRINK_UNBOUND,
+			0,
+		}, *s = shrink;
+		gfp_t gfp = noreclaim;
+
+		do {
+			cond_resched();
+			page = shmem_read_mapping_page_gfp(mapping, i, gfp);
+			if (!IS_ERR(page))
+				break;
+
+			if (!*s) {
+				ret = PTR_ERR(page);
+				goto err_sg;
+			}
+
+			i915_gem_shrink(NULL, i915, 2 * page_count, NULL, *s++);
+
+			/*
+			 * We've tried hard to allocate the memory by reaping
+			 * our own buffer, now let the real VM do its job and
+			 * go down in flames if truly OOM.
+			 *
+			 * However, since graphics tend to be disposable,
+			 * defer the oom here by reporting the ENOMEM back
+			 * to userspace.
+			 */
+			if (!*s) {
+				/* reclaim and warn, but no oom */
+				gfp = mapping_gfp_mask(mapping);
+
+				/*
+				 * Our bo are always dirty and so we require
+				 * kswapd to reclaim our pages (direct reclaim
+				 * does not effectively begin pageout of our
+				 * buffers on its own). However, direct reclaim
+				 * only waits for kswapd when under allocation
+				 * congestion. So as a result __GFP_RECLAIM is
+				 * unreliable and fails to actually reclaim our
+				 * dirty pages -- unless you try over and over
+				 * again with !__GFP_NORETRY. However, we still
+				 * want to fail this allocation rather than
+				 * trigger the out-of-memory killer and for
+				 * this we want __GFP_RETRY_MAYFAIL.
+				 */
+				gfp |= __GFP_RETRY_MAYFAIL | __GFP_NOWARN;
+			}
+		} while (1);
+
+		if (!i ||
+		    sg->length >= max_segment ||
+		    page_to_pfn(page) != last_pfn + 1) {
+			if (i)
+				sg = sg_next(sg);
+
+			st->nents++;
+			sg_set_page(sg, page, PAGE_SIZE, 0);
+		} else {
+			sg->length += PAGE_SIZE;
+		}
+		last_pfn = page_to_pfn(page);
+
+		/* Check that the i965g/gm workaround works. */
+		GEM_BUG_ON(gfp & __GFP_DMA32 && last_pfn >= 0x00100000UL);
+	}
+	if (sg) /* loop terminated early; short sg table */
+		sg_mark_end(sg);
+
+	/* Trim unused sg entries to avoid wasting memory. */
+	i915_sg_trim(st);
+
+	return 0;
+err_sg:
+	sg_mark_end(sg);
+	if (sg != st->sgl) {
+		shmem_sg_free_table(st, mapping, false, false);
+	} else {
+		mapping_clear_unevictable(mapping);
+		sg_free_table(st);
+	}
+
+	/*
+	 * shmemfs first checks if there is enough memory to allocate the page
+	 * and reports ENOSPC should there be insufficient, along with the usual
+	 * ENOMEM for a genuine allocation failure.
+	 *
+	 * We use ENOSPC in our driver to mean that we have run out of aperture
+	 * space and so want to translate the error from shmemfs back to our
+	 * usual understanding of ENOMEM.
+	 */
+	if (ret == -ENOSPC)
+		ret = -ENOMEM;
+
+	return ret;
+}
+
+static int shmem_get_pages(struct drm_i915_gem_object *obj)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	struct intel_memory_region *mem = obj->mm.region;
+	struct address_space *mapping = obj->base.filp->f_mapping;
+	const unsigned long page_count = obj->base.size / PAGE_SIZE;
+	unsigned int max_segment = i915_sg_segment_size(i915->drm.dev);
+	struct sg_table *st;
+	struct sgt_iter sgt_iter;
+	struct page *page;
+	int ret;
+
+	/*
+	 * Assert that the object is not currently in any GPU domain. As it
+	 * wasn't in the GTT, there shouldn't be any way it could have been in
+	 * a GPU cache
+	 */
+	GEM_BUG_ON(obj->read_domains & I915_GEM_GPU_DOMAINS);
+	GEM_BUG_ON(obj->write_domain & I915_GEM_GPU_DOMAINS);
+
+rebuild_st:
+	st = kmalloc(sizeof(*st), GFP_KERNEL | __GFP_NOWARN);
+	if (!st)
+		return -ENOMEM;
+
+	ret = shmem_sg_alloc_table(i915, st, obj->base.size, mem, mapping,
+				   max_segment);
+	if (ret)
+		goto err_st;
+
+	ret = i915_gem_gtt_prepare_pages(obj, st);
+	if (ret) {
+		/*
+		 * DMA remapping failed? One possible cause is that
+		 * it could not reserve enough large entries, asking
+		 * for PAGE_SIZE chunks instead may be helpful.
+		 */
+		if (max_segment > PAGE_SIZE) {
+			for_each_sgt_page(page, sgt_iter, st)
+				put_page(page);
+			sg_free_table(st);
+			kfree(st);
+
+			max_segment = PAGE_SIZE;
+			goto rebuild_st;
+		} else {
+			dev_warn(i915->drm.dev,
+				 "Failed to DMA remap %lu pages\n",
+				 page_count);
+			goto err_pages;
+		}
+	}
+
+	if (i915_gem_object_needs_bit17_swizzle(obj))
+		i915_gem_object_do_bit_17_swizzle(obj, st);
+
+	if (i915_gem_object_can_bypass_llc(obj))
+		obj->cache_dirty = true;
+
+	__i915_gem_object_set_pages(obj, st, i915_sg_dma_sizes(st->sgl));
+
+	return 0;
+
+err_pages:
+	shmem_sg_free_table(st, mapping, false, false);
+	/*
+	 * shmemfs first checks if there is enough memory to allocate the page
+	 * and reports ENOSPC should there be insufficient, along with the usual
+	 * ENOMEM for a genuine allocation failure.
+	 *
+	 * We use ENOSPC in our driver to mean that we have run out of aperture
+	 * space and so want to translate the error from shmemfs back to our
+	 * usual understanding of ENOMEM.
+	 */
+err_st:
+	if (ret == -ENOSPC)
+		ret = -ENOMEM;
+
+	kfree(st);
+
+	return ret;
+}
+
+static int
+shmem_truncate(struct drm_i915_gem_object *obj)
+{
+	/*
+	 * Our goal here is to return as much of the memory as
+	 * is possible back to the system as we are called from OOM.
+	 * To do this we must instruct the shmfs to drop all of its
+	 * backing pages, *now*.
+	 */
+	shmem_truncate_range(file_inode(obj->base.filp), 0, (loff_t)-1);
+	obj->mm.madv = __I915_MADV_PURGED;
+	obj->mm.pages = ERR_PTR(-EFAULT);
+
+	return 0;
+}
+
+void __shmem_writeback(size_t size, struct address_space *mapping)
+{
+	struct writeback_control wbc = {
+		.sync_mode = WB_SYNC_NONE,
+		.nr_to_write = SWAP_CLUSTER_MAX,
+		.range_start = 0,
+		.range_end = LLONG_MAX,
+		.for_reclaim = 1,
+	};
+	unsigned long i;
+
+	/*
+	 * Leave mmapings intact (GTT will have been revoked on unbinding,
+	 * leaving only CPU mmapings around) and add those pages to the LRU
+	 * instead of invoking writeback so they are aged and paged out
+	 * as normal.
+	 */
+
+	/* Begin writeback on each dirty page */
+	for (i = 0; i < size >> PAGE_SHIFT; i++) {
+		struct page *page;
+
+		page = find_lock_page(mapping, i);
+		if (!page)
+			continue;
+
+		if (!page_mapped(page) && clear_page_dirty_for_io(page)) {
+			int ret;
+
+			SetPageReclaim(page);
+			ret = mapping->a_ops->writepage(page, &wbc);
+			if (!PageWriteback(page))
+				ClearPageReclaim(page);
+			if (!ret)
+				goto put;
+		}
+		unlock_page(page);
+put:
+		put_page(page);
+	}
+}
+
+static void
+shmem_writeback(struct drm_i915_gem_object *obj)
+{
+	__shmem_writeback(obj->base.size, obj->base.filp->f_mapping);
+}
+
+static int shmem_shrink(struct drm_i915_gem_object *obj, unsigned int flags)
+{
+	switch (obj->mm.madv) {
+	case I915_MADV_DONTNEED:
+		return i915_gem_object_truncate(obj);
+	case __I915_MADV_PURGED:
+		return 0;
+	}
+
+	if (flags & I915_GEM_OBJECT_SHRINK_WRITEBACK)
+		shmem_writeback(obj);
+
+	return 0;
+}
+
+void
+__i915_gem_object_release_shmem(struct drm_i915_gem_object *obj,
+				struct sg_table *pages,
+				bool needs_clflush)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+
+	GEM_BUG_ON(obj->mm.madv == __I915_MADV_PURGED);
+
+	if (obj->mm.madv == I915_MADV_DONTNEED)
+		obj->mm.dirty = false;
+
+	if (needs_clflush &&
+	    (obj->read_domains & I915_GEM_DOMAIN_CPU) == 0 &&
+	    !(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_READ))
+		drm_clflush_sg(pages);
+
+	__start_cpu_write(obj);
+	/*
+	 * On non-LLC igfx platforms, force the flush-on-acquire if this is ever
+	 * swapped-in. Our async flush path is not trust worthy enough yet(and
+	 * happens in the wrong order), and with some tricks it's conceivable
+	 * for userspace to change the cache-level to I915_CACHE_NONE after the
+	 * pages are swapped-in, and since execbuf binds the object before doing
+	 * the async flush, we have a race window.
+	 */
+	if (!HAS_LLC(i915) && !IS_DGFX(i915))
+		obj->cache_dirty = true;
+}
+
+void i915_gem_object_put_pages_shmem(struct drm_i915_gem_object *obj, struct sg_table *pages)
+{
+	__i915_gem_object_release_shmem(obj, pages, true);
+
+	i915_gem_gtt_finish_pages(obj, pages);
+
+	if (i915_gem_object_needs_bit17_swizzle(obj))
+		i915_gem_object_save_bit_17_swizzle(obj, pages);
+
+	shmem_sg_free_table(pages, file_inode(obj->base.filp)->i_mapping,
+			    obj->mm.dirty, obj->mm.madv == I915_MADV_WILLNEED);
+	kfree(pages);
+	obj->mm.dirty = false;
+}
+
+static void
+shmem_put_pages(struct drm_i915_gem_object *obj, struct sg_table *pages)
+{
+	if (likely(i915_gem_object_has_struct_page(obj)))
+		i915_gem_object_put_pages_shmem(obj, pages);
+	else
+		i915_gem_object_put_pages_phys(obj, pages);
+}
+
+static int
+shmem_pwrite(struct drm_i915_gem_object *obj,
+	     const struct drm_i915_gem_pwrite *arg)
+{
+	struct address_space *mapping = obj->base.filp->f_mapping;
+	const struct address_space_operations *aops = mapping->a_ops;
+	char __user *user_data = u64_to_user_ptr(arg->data_ptr);
+	u64 remain, offset;
+	unsigned int pg;
+
+	/* Caller already validated user args */
+	GEM_BUG_ON(!access_ok(user_data, arg->size));
+
+	if (!i915_gem_object_has_struct_page(obj))
+		return i915_gem_object_pwrite_phys(obj, arg);
+
+	/*
+	 * Before we instantiate/pin the backing store for our use, we
+	 * can prepopulate the shmemfs filp efficiently using a write into
+	 * the pagecache. We avoid the penalty of instantiating all the
+	 * pages, important if the user is just writing to a few and never
+	 * uses the object on the GPU, and using a direct write into shmemfs
+	 * allows it to avoid the cost of retrieving a page (either swapin
+	 * or clearing-before-use) before it is overwritten.
+	 */
+	if (i915_gem_object_has_pages(obj))
+		return -ENODEV;
+
+	if (obj->mm.madv != I915_MADV_WILLNEED)
+		return -EFAULT;
+
+	/*
+	 * Before the pages are instantiated the object is treated as being
+	 * in the CPU domain. The pages will be clflushed as required before
+	 * use, and we can freely write into the pages directly. If userspace
+	 * races pwrite with any other operation; corruption will ensue -
+	 * that is userspace's prerogative!
+	 */
+
+	remain = arg->size;
+	offset = arg->offset;
+	pg = offset_in_page(offset);
+
+	do {
+		unsigned int len, unwritten;
+		struct page *page;
+		void *data, *vaddr;
+		int err;
+		char c;
+
+		len = PAGE_SIZE - pg;
+		if (len > remain)
+			len = remain;
+
+		/* Prefault the user page to reduce potential recursion */
+		err = __get_user(c, user_data);
+		if (err)
+			return err;
+
+		err = __get_user(c, user_data + len - 1);
+		if (err)
+			return err;
+
+		err = aops->write_begin(obj->base.filp, mapping, offset, len,
+					&page, &data);
+		if (err < 0)
+			return err;
+
+		vaddr = kmap_atomic(page);
+		unwritten = __copy_from_user_inatomic(vaddr + pg,
+						      user_data,
+						      len);
+		kunmap_atomic(vaddr);
+
+		err = aops->write_end(obj->base.filp, mapping, offset, len,
+				      len - unwritten, page, data);
+		if (err < 0)
+			return err;
+
+		/* We don't handle -EFAULT, leave it to the caller to check */
+		if (unwritten)
+			return -ENODEV;
+
+		remain -= len;
+		user_data += len;
+		offset += len;
+		pg = 0;
+	} while (remain);
+
+	return 0;
+}
+
+static int
+shmem_pread(struct drm_i915_gem_object *obj,
+	    const struct drm_i915_gem_pread *arg)
+{
+	if (!i915_gem_object_has_struct_page(obj))
+		return i915_gem_object_pread_phys(obj, arg);
+
+	return -ENODEV;
+}
+
+static void shmem_release(struct drm_i915_gem_object *obj)
+{
+	if (i915_gem_object_has_struct_page(obj))
+		i915_gem_object_release_memory_region(obj);
+
+	fput(obj->base.filp);
+}
+
+const struct drm_i915_gem_object_ops i915_gem_shmem_ops = {
+	.name = "i915_gem_object_shmem",
+	.flags = I915_GEM_OBJECT_IS_SHRINKABLE,
+
+	.get_pages = shmem_get_pages,
+	.put_pages = shmem_put_pages,
+	.truncate = shmem_truncate,
+	.shrink = shmem_shrink,
+
+	.pwrite = shmem_pwrite,
+	.pread = shmem_pread,
+
+	.release = shmem_release,
+};
+
+static int __create_shmem(struct drm_i915_private *i915,
+			  struct drm_gem_object *obj,
+			  resource_size_t size)
+{
+	unsigned long flags = VM_NORESERVE;
+	struct file *filp;
+
+	drm_gem_private_object_init(&i915->drm, obj, size);
+
+	if (i915->mm.gemfs)
+		filp = shmem_file_setup_with_mnt(i915->mm.gemfs, "i915", size,
+						 flags);
+	else
+		filp = shmem_file_setup("i915", size, flags);
+	if (IS_ERR(filp))
+		return PTR_ERR(filp);
+
+	obj->filp = filp;
+	return 0;
+}
+
+static int shmem_object_init(struct intel_memory_region *mem,
+			     struct drm_i915_gem_object *obj,
+			     resource_size_t offset,
+			     resource_size_t size,
+			     resource_size_t page_size,
+			     unsigned int flags)
+{
+	static struct lock_class_key lock_class;
+	struct drm_i915_private *i915 = mem->i915;
+	struct address_space *mapping;
+	unsigned int cache_level;
+	gfp_t mask;
+	int ret;
+
+	ret = __create_shmem(i915, &obj->base, size);
+	if (ret)
+		return ret;
+
+	mask = GFP_HIGHUSER | __GFP_RECLAIMABLE;
+	if (IS_I965GM(i915) || IS_I965G(i915)) {
+		/* 965gm cannot relocate objects above 4GiB. */
+		mask &= ~__GFP_HIGHMEM;
+		mask |= __GFP_DMA32;
+	}
+
+	mapping = obj->base.filp->f_mapping;
+	mapping_set_gfp_mask(mapping, mask);
+	GEM_BUG_ON(!(mapping_gfp_mask(mapping) & __GFP_RECLAIM));
+
+	i915_gem_object_init(obj, &i915_gem_shmem_ops, &lock_class, flags);
+	obj->mem_flags |= I915_BO_FLAG_STRUCT_PAGE;
+	obj->write_domain = I915_GEM_DOMAIN_CPU;
+	obj->read_domains = I915_GEM_DOMAIN_CPU;
+
+	if (HAS_LLC(i915))
+		/* On some devices, we can have the GPU use the LLC (the CPU
+		 * cache) for about a 10% performance improvement
+		 * compared to uncached.  Graphics requests other than
+		 * display scanout are coherent with the CPU in
+		 * accessing this cache.  This means in this mode we
+		 * don't need to clflush on the CPU side, and on the
+		 * GPU side we only need to flush internal caches to
+		 * get data visible to the CPU.
+		 *
+		 * However, we maintain the display planes as UC, and so
+		 * need to rebind when first used as such.
+		 */
+		cache_level = I915_CACHE_LLC;
+	else
+		cache_level = I915_CACHE_NONE;
+
+	i915_gem_object_set_cache_coherency(obj, cache_level);
+
+	i915_gem_object_init_memory_region(obj, mem);
+
+	return 0;
+}
+
+struct drm_i915_gem_object *
+i915_gem_object_create_shmem(struct drm_i915_private *i915,
+			     resource_size_t size)
+{
+	return i915_gem_object_create_region(i915->mm.regions[INTEL_REGION_SMEM],
+					     size, 0, 0);
+}
+
+/* Allocate a new GEM object and fill it with the supplied data */
+struct drm_i915_gem_object *
+i915_gem_object_create_shmem_from_data(struct drm_i915_private *dev_priv,
+				       const void *data, resource_size_t size)
+{
+	struct drm_i915_gem_object *obj;
+	struct file *file;
+	const struct address_space_operations *aops;
+	resource_size_t offset;
+	int err;
+
+	GEM_WARN_ON(IS_DGFX(dev_priv));
+	obj = i915_gem_object_create_shmem(dev_priv, round_up(size, PAGE_SIZE));
+	if (IS_ERR(obj))
+		return obj;
+
+	GEM_BUG_ON(obj->write_domain != I915_GEM_DOMAIN_CPU);
+
+	file = obj->base.filp;
+	aops = file->f_mapping->a_ops;
+	offset = 0;
+	do {
+		unsigned int len = min_t(typeof(size), size, PAGE_SIZE);
+		struct page *page;
+		void *pgdata, *vaddr;
+
+		err = aops->write_begin(file, file->f_mapping, offset, len,
+					&page, &pgdata);
+		if (err < 0)
+			goto fail;
+
+		vaddr = kmap(page);
+		memcpy(vaddr, data, len);
+		kunmap(page);
+
+		err = aops->write_end(file, file->f_mapping, offset, len, len,
+				      page, pgdata);
+		if (err < 0)
+			goto fail;
+
+		size -= len;
+		data += len;
+		offset += len;
+	} while (size);
+
+	return obj;
+
+fail:
+	i915_gem_object_put(obj);
+	return ERR_PTR(err);
+}
+
+static int init_shmem(struct intel_memory_region *mem)
+{
+	i915_gemfs_init(mem->i915);
+	intel_memory_region_set_name(mem, "system");
+
+	return 0; /* We have fallback to the kernel mnt if gemfs init failed. */
+}
+
+static int release_shmem(struct intel_memory_region *mem)
+{
+	i915_gemfs_fini(mem->i915);
+	return 0;
+}
+
+static const struct intel_memory_region_ops shmem_region_ops = {
+	.init = init_shmem,
+	.release = release_shmem,
+	.init_object = shmem_object_init,
+};
+
+struct intel_memory_region *i915_gem_shmem_setup(struct drm_i915_private *i915,
+						 u16 type, u16 instance)
+{
+	return intel_memory_region_create(i915, 0,
+					  totalram_pages() << PAGE_SHIFT,
+					  PAGE_SIZE, 0, 0,
+					  type, instance,
+					  &shmem_region_ops);
+}
+
+bool i915_gem_object_is_shmem(const struct drm_i915_gem_object *obj)
+{
+	return obj->ops == &i915_gem_shmem_ops;
+}