1 files changed, 544 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
new file mode 100644
index 000000000000..b36ad269f4ea
--- /dev/null
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
@@ -0,0 +1,544 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2014-2016 Intel Corporation
+ */
+
+#include "i915_drv.h"
+#include "i915_gem_object.h"
+#include "i915_scatterlist.h"
+
+void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj,
+				 struct sg_table *pages,
+				 unsigned int sg_page_sizes)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	unsigned long supported = INTEL_INFO(i915)->page_sizes;
+	int i;
+
+	lockdep_assert_held(&obj->mm.lock);
+
+	/* Make the pages coherent with the GPU (flushing any swapin). */
+	if (obj->cache_dirty) {
+		obj->write_domain = 0;
+		if (i915_gem_object_has_struct_page(obj))
+			drm_clflush_sg(pages);
+		obj->cache_dirty = false;
+	}
+
+	obj->mm.get_page.sg_pos = pages->sgl;
+	obj->mm.get_page.sg_idx = 0;
+
+	obj->mm.pages = pages;
+
+	if (i915_gem_object_is_tiled(obj) &&
+	    i915->quirks & QUIRK_PIN_SWIZZLED_PAGES) {
+		GEM_BUG_ON(obj->mm.quirked);
+		__i915_gem_object_pin_pages(obj);
+		obj->mm.quirked = true;
+	}
+
+	GEM_BUG_ON(!sg_page_sizes);
+	obj->mm.page_sizes.phys = sg_page_sizes;
+
+	/*
+	 * Calculate the supported page-sizes which fit into the given
+	 * sg_page_sizes. This will give us the page-sizes which we may be able
+	 * to use opportunistically when later inserting into the GTT. For
+	 * example if phys=2G, then in theory we should be able to use 1G, 2M,
+	 * 64K or 4K pages, although in practice this will depend on a number of
+	 * other factors.
+	 */
+	obj->mm.page_sizes.sg = 0;
+	for_each_set_bit(i, &supported, ilog2(I915_GTT_MAX_PAGE_SIZE) + 1) {
+		if (obj->mm.page_sizes.phys & ~0u << i)
+			obj->mm.page_sizes.sg |= BIT(i);
+	}
+	GEM_BUG_ON(!HAS_PAGE_SIZES(i915, obj->mm.page_sizes.sg));
+
+	if (i915_gem_object_is_shrinkable(obj)) {
+		struct list_head *list;
+		unsigned long flags;
+
+		spin_lock_irqsave(&i915->mm.obj_lock, flags);
+
+		i915->mm.shrink_count++;
+		i915->mm.shrink_memory += obj->base.size;
+
+		if (obj->mm.madv != I915_MADV_WILLNEED)
+			list = &i915->mm.purge_list;
+		else
+			list = &i915->mm.shrink_list;
+		list_add_tail(&obj->mm.link, list);
+
+		spin_unlock_irqrestore(&i915->mm.obj_lock, flags);
+	}
+}
+
+int ____i915_gem_object_get_pages(struct drm_i915_gem_object *obj)
+{
+	int err;
+
+	if (unlikely(obj->mm.madv != I915_MADV_WILLNEED)) {
+		DRM_DEBUG("Attempting to obtain a purgeable object\n");
+		return -EFAULT;
+	}
+
+	err = obj->ops->get_pages(obj);
+	GEM_BUG_ON(!err && !i915_gem_object_has_pages(obj));
+
+	return err;
+}
+
+/* Ensure that the associated pages are gathered from the backing storage
+ * and pinned into our object. i915_gem_object_pin_pages() may be called
+ * multiple times before they are released by a single call to
+ * i915_gem_object_unpin_pages() - once the pages are no longer referenced
+ * either as a result of memory pressure (reaping pages under the shrinker)
+ * or as the object is itself released.
+ */
+int __i915_gem_object_get_pages(struct drm_i915_gem_object *obj)
+{
+	int err;
+
+	err = mutex_lock_interruptible(&obj->mm.lock);
+	if (err)
+		return err;
+
+	if (unlikely(!i915_gem_object_has_pages(obj))) {
+		GEM_BUG_ON(i915_gem_object_has_pinned_pages(obj));
+
+		err = ____i915_gem_object_get_pages(obj);
+		if (err)
+			goto unlock;
+
+		smp_mb__before_atomic();
+	}
+	atomic_inc(&obj->mm.pages_pin_count);
+
+unlock:
+	mutex_unlock(&obj->mm.lock);
+	return err;
+}
+
+/* Immediately discard the backing storage */
+void i915_gem_object_truncate(struct drm_i915_gem_object *obj)
+{
+	drm_gem_free_mmap_offset(&obj->base);
+	if (obj->ops->truncate)
+		obj->ops->truncate(obj);
+}
+
+/* Try to discard unwanted pages */
+void i915_gem_object_writeback(struct drm_i915_gem_object *obj)
+{
+	lockdep_assert_held(&obj->mm.lock);
+	GEM_BUG_ON(i915_gem_object_has_pages(obj));
+
+	if (obj->ops->writeback)
+		obj->ops->writeback(obj);
+}
+
+static void __i915_gem_object_reset_page_iter(struct drm_i915_gem_object *obj)
+{
+	struct radix_tree_iter iter;
+	void __rcu **slot;
+
+	rcu_read_lock();
+	radix_tree_for_each_slot(slot, &obj->mm.get_page.radix, &iter, 0)
+		radix_tree_delete(&obj->mm.get_page.radix, iter.index);
+	rcu_read_unlock();
+}
+
+struct sg_table *
+__i915_gem_object_unset_pages(struct drm_i915_gem_object *obj)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	struct sg_table *pages;
+
+	pages = fetch_and_zero(&obj->mm.pages);
+	if (IS_ERR_OR_NULL(pages))
+		return pages;
+
+	if (i915_gem_object_is_shrinkable(obj)) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&i915->mm.obj_lock, flags);
+
+		list_del(&obj->mm.link);
+		i915->mm.shrink_count--;
+		i915->mm.shrink_memory -= obj->base.size;
+
+		spin_unlock_irqrestore(&i915->mm.obj_lock, flags);
+	}
+
+	if (obj->mm.mapping) {
+		void *ptr;
+
+		ptr = page_mask_bits(obj->mm.mapping);
+		if (is_vmalloc_addr(ptr))
+			vunmap(ptr);
+		else
+			kunmap(kmap_to_page(ptr));
+
+		obj->mm.mapping = NULL;
+	}
+
+	__i915_gem_object_reset_page_iter(obj);
+	obj->mm.page_sizes.phys = obj->mm.page_sizes.sg = 0;
+
+	return pages;
+}
+
+int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj,
+				enum i915_mm_subclass subclass)
+{
+	struct sg_table *pages;
+	int err;
+
+	if (i915_gem_object_has_pinned_pages(obj))
+		return -EBUSY;
+
+	GEM_BUG_ON(atomic_read(&obj->bind_count));
+
+	/* May be called by shrinker from within get_pages() (on another bo) */
+	mutex_lock_nested(&obj->mm.lock, subclass);
+	if (unlikely(atomic_read(&obj->mm.pages_pin_count))) {
+		err = -EBUSY;
+		goto unlock;
+	}
+
+	/*
+	 * ->put_pages might need to allocate memory for the bit17 swizzle
+	 * array, hence protect them from being reaped by removing them from gtt
+	 * lists early.
+	 */
+	pages = __i915_gem_object_unset_pages(obj);
+
+	/*
+	 * XXX Temporary hijinx to avoid updating all backends to handle
+	 * NULL pages. In the future, when we have more asynchronous
+	 * get_pages backends we should be better able to handle the
+	 * cancellation of the async task in a more uniform manner.
+	 */
+	if (!pages && !i915_gem_object_needs_async_cancel(obj))
+		pages = ERR_PTR(-EINVAL);
+
+	if (!IS_ERR(pages))
+		obj->ops->put_pages(obj, pages);
+
+	err = 0;
+unlock:
+	mutex_unlock(&obj->mm.lock);
+
+	return err;
+}
+
+/* The 'mapping' part of i915_gem_object_pin_map() below */
+static void *i915_gem_object_map(const struct drm_i915_gem_object *obj,
+				 enum i915_map_type type)
+{
+	unsigned long n_pages = obj->base.size >> PAGE_SHIFT;
+	struct sg_table *sgt = obj->mm.pages;
+	struct sgt_iter sgt_iter;
+	struct page *page;
+	struct page *stack_pages[32];
+	struct page **pages = stack_pages;
+	unsigned long i = 0;
+	pgprot_t pgprot;
+	void *addr;
+
+	/* A single page can always be kmapped */
+	if (n_pages == 1 && type == I915_MAP_WB)
+		return kmap(sg_page(sgt->sgl));
+
+	if (n_pages > ARRAY_SIZE(stack_pages)) {
+		/* Too big for stack -- allocate temporary array instead */
+		pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
+		if (!pages)
+			return NULL;
+	}
+
+	for_each_sgt_page(page, sgt_iter, sgt)
+		pages[i++] = page;
+
+	/* Check that we have the expected number of pages */
+	GEM_BUG_ON(i != n_pages);
+
+	switch (type) {
+	default:
+		MISSING_CASE(type);
+		/* fallthrough to use PAGE_KERNEL anyway */
+	case I915_MAP_WB:
+		pgprot = PAGE_KERNEL;
+		break;
+	case I915_MAP_WC:
+		pgprot = pgprot_writecombine(PAGE_KERNEL_IO);
+		break;
+	}
+	addr = vmap(pages, n_pages, 0, pgprot);
+
+	if (pages != stack_pages)
+		kvfree(pages);
+
+	return addr;
+}
+
+/* get, pin, and map the pages of the object into kernel space */
+void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj,
+			      enum i915_map_type type)
+{
+	enum i915_map_type has_type;
+	bool pinned;
+	void *ptr;
+	int err;
+
+	if (unlikely(!i915_gem_object_has_struct_page(obj)))
+		return ERR_PTR(-ENXIO);
+
+	err = mutex_lock_interruptible(&obj->mm.lock);
+	if (err)
+		return ERR_PTR(err);
+
+	pinned = !(type & I915_MAP_OVERRIDE);
+	type &= ~I915_MAP_OVERRIDE;
+
+	if (!atomic_inc_not_zero(&obj->mm.pages_pin_count)) {
+		if (unlikely(!i915_gem_object_has_pages(obj))) {
+			GEM_BUG_ON(i915_gem_object_has_pinned_pages(obj));
+
+			err = ____i915_gem_object_get_pages(obj);
+			if (err)
+				goto err_unlock;
+
+			smp_mb__before_atomic();
+		}
+		atomic_inc(&obj->mm.pages_pin_count);
+		pinned = false;
+	}
+	GEM_BUG_ON(!i915_gem_object_has_pages(obj));
+
+	ptr = page_unpack_bits(obj->mm.mapping, &has_type);
+	if (ptr && has_type != type) {
+		if (pinned) {
+			err = -EBUSY;
+			goto err_unpin;
+		}
+
+		if (is_vmalloc_addr(ptr))
+			vunmap(ptr);
+		else
+			kunmap(kmap_to_page(ptr));
+
+		ptr = obj->mm.mapping = NULL;
+	}
+
+	if (!ptr) {
+		ptr = i915_gem_object_map(obj, type);
+		if (!ptr) {
+			err = -ENOMEM;
+			goto err_unpin;
+		}
+
+		obj->mm.mapping = page_pack_bits(ptr, type);
+	}
+
+out_unlock:
+	mutex_unlock(&obj->mm.lock);
+	return ptr;
+
+err_unpin:
+	atomic_dec(&obj->mm.pages_pin_count);
+err_unlock:
+	ptr = ERR_PTR(err);
+	goto out_unlock;
+}
+
+void __i915_gem_object_flush_map(struct drm_i915_gem_object *obj,
+				 unsigned long offset,
+				 unsigned long size)
+{
+	enum i915_map_type has_type;
+	void *ptr;
+
+	GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));
+	GEM_BUG_ON(range_overflows_t(typeof(obj->base.size),
+				     offset, size, obj->base.size));
+
+	obj->mm.dirty = true;
+
+	if (obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE)
+		return;
+
+	ptr = page_unpack_bits(obj->mm.mapping, &has_type);
+	if (has_type == I915_MAP_WC)
+		return;
+
+	drm_clflush_virt_range(ptr + offset, size);
+	if (size == obj->base.size) {
+		obj->write_domain &= ~I915_GEM_DOMAIN_CPU;
+		obj->cache_dirty = false;
+	}
+}
+
+struct scatterlist *
+i915_gem_object_get_sg(struct drm_i915_gem_object *obj,
+		       unsigned int n,
+		       unsigned int *offset)
+{
+	struct i915_gem_object_page_iter *iter = &obj->mm.get_page;
+	struct scatterlist *sg;
+	unsigned int idx, count;
+
+	might_sleep();
+	GEM_BUG_ON(n >= obj->base.size >> PAGE_SHIFT);
+	GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));
+
+	/* As we iterate forward through the sg, we record each entry in a
+	 * radixtree for quick repeated (backwards) lookups. If we have seen
+	 * this index previously, we will have an entry for it.
+	 *
+	 * Initial lookup is O(N), but this is amortized to O(1) for
+	 * sequential page access (where each new request is consecutive
+	 * to the previous one). Repeated lookups are O(lg(obj->base.size)),
+	 * i.e. O(1) with a large constant!
+	 */
+	if (n < READ_ONCE(iter->sg_idx))
+		goto lookup;
+
+	mutex_lock(&iter->lock);
+
+	/* We prefer to reuse the last sg so that repeated lookup of this
+	 * (or the subsequent) sg are fast - comparing against the last
+	 * sg is faster than going through the radixtree.
+	 */
+
+	sg = iter->sg_pos;
+	idx = iter->sg_idx;
+	count = __sg_page_count(sg);
+
+	while (idx + count <= n) {
+		void *entry;
+		unsigned long i;
+		int ret;
+
+		/* If we cannot allocate and insert this entry, or the
+		 * individual pages from this range, cancel updating the
+		 * sg_idx so that on this lookup we are forced to linearly
+		 * scan onwards, but on future lookups we will try the
+		 * insertion again (in which case we need to be careful of
+		 * the error return reporting that we have already inserted
+		 * this index).
+		 */
+		ret = radix_tree_insert(&iter->radix, idx, sg);
+		if (ret && ret != -EEXIST)
+			goto scan;
+
+		entry = xa_mk_value(idx);
+		for (i = 1; i < count; i++) {
+			ret = radix_tree_insert(&iter->radix, idx + i, entry);
+			if (ret && ret != -EEXIST)
+				goto scan;
+		}
+
+		idx += count;
+		sg = ____sg_next(sg);
+		count = __sg_page_count(sg);
+	}
+
+scan:
+	iter->sg_pos = sg;
+	iter->sg_idx = idx;
+
+	mutex_unlock(&iter->lock);
+
+	if (unlikely(n < idx)) /* insertion completed by another thread */
+		goto lookup;
+
+	/* In case we failed to insert the entry into the radixtree, we need
+	 * to look beyond the current sg.
+	 */
+	while (idx + count <= n) {
+		idx += count;
+		sg = ____sg_next(sg);
+		count = __sg_page_count(sg);
+	}
+
+	*offset = n - idx;
+	return sg;
+
+lookup:
+	rcu_read_lock();
+
+	sg = radix_tree_lookup(&iter->radix, n);
+	GEM_BUG_ON(!sg);
+
+	/* If this index is in the middle of multi-page sg entry,
+	 * the radix tree will contain a value entry that points
+	 * to the start of that range. We will return the pointer to
+	 * the base page and the offset of this page within the
+	 * sg entry's range.
+	 */
+	*offset = 0;
+	if (unlikely(xa_is_value(sg))) {
+		unsigned long base = xa_to_value(sg);
+
+		sg = radix_tree_lookup(&iter->radix, base);
+		GEM_BUG_ON(!sg);
+
+		*offset = n - base;
+	}
+
+	rcu_read_unlock();
+
+	return sg;
+}
+
+struct page *
+i915_gem_object_get_page(struct drm_i915_gem_object *obj, unsigned int n)
+{
+	struct scatterlist *sg;
+	unsigned int offset;
+
+	GEM_BUG_ON(!i915_gem_object_has_struct_page(obj));
+
+	sg = i915_gem_object_get_sg(obj, n, &offset);
+	return nth_page(sg_page(sg), offset);
+}
+
+/* Like i915_gem_object_get_page(), but mark the returned page dirty */
+struct page *
+i915_gem_object_get_dirty_page(struct drm_i915_gem_object *obj,
+			       unsigned int n)
+{
+	struct page *page;
+
+	page = i915_gem_object_get_page(obj, n);
+	if (!obj->mm.dirty)
+		set_page_dirty(page);
+
+	return page;
+}
+
+dma_addr_t
+i915_gem_object_get_dma_address_len(struct drm_i915_gem_object *obj,
+				    unsigned long n,
+				    unsigned int *len)
+{
+	struct scatterlist *sg;
+	unsigned int offset;
+
+	sg = i915_gem_object_get_sg(obj, n, &offset);
+
+	if (len)
+		*len = sg_dma_len(sg) - (offset << PAGE_SHIFT);
+
+	return sg_dma_address(sg) + (offset << PAGE_SHIFT);
+}
+
+dma_addr_t
+i915_gem_object_get_dma_address(struct drm_i915_gem_object *obj,
+				unsigned long n)
+{
+	return i915_gem_object_get_dma_address_len(obj, n, NULL);
+}