1 files changed, 274 insertions, 0 deletions

diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
new file mode 100644
index 000000000..3c812fbd1
--- /dev/null
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
@@ -0,0 +1,274 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
+
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-mapping.h>
+
+#include <drm/panfrost_drm.h>
+#include "panfrost_device.h"
+#include "panfrost_gem.h"
+#include "panfrost_mmu.h"
+
+/* Called DRM core on the last userspace/kernel unreference of the
+ * BO.
+ */
+static void panfrost_gem_free_object(struct drm_gem_object *obj)
+{
+	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
+	struct panfrost_device *pfdev = obj->dev->dev_private;
+
+	/*
+	 * Make sure the BO is no longer inserted in the shrinker list before
+	 * taking care of the destruction itself. If we don't do that we have a
+	 * race condition between this function and what's done in
+	 * panfrost_gem_shrinker_scan().
+	 */
+	mutex_lock(&pfdev->shrinker_lock);
+	list_del_init(&bo->base.madv_list);
+	mutex_unlock(&pfdev->shrinker_lock);
+
+	/*
+	 * If we still have mappings attached to the BO, there's a problem in
+	 * our refcounting.
+	 */
+	WARN_ON_ONCE(!list_empty(&bo->mappings.list));
+
+	if (bo->sgts) {
+		int i;
+		int n_sgt = bo->base.base.size / SZ_2M;
+
+		for (i = 0; i < n_sgt; i++) {
+			if (bo->sgts[i].sgl) {
+				dma_unmap_sgtable(pfdev->dev, &bo->sgts[i],
+						  DMA_BIDIRECTIONAL, 0);
+				sg_free_table(&bo->sgts[i]);
+			}
+		}
+		kvfree(bo->sgts);
+	}
+
+	drm_gem_shmem_free(&bo->base);
+}
+
+struct panfrost_gem_mapping *
+panfrost_gem_mapping_get(struct panfrost_gem_object *bo,
+			 struct panfrost_file_priv *priv)
+{
+	struct panfrost_gem_mapping *iter, *mapping = NULL;
+
+	mutex_lock(&bo->mappings.lock);
+	list_for_each_entry(iter, &bo->mappings.list, node) {
+		if (iter->mmu == priv->mmu) {
+			kref_get(&iter->refcount);
+			mapping = iter;
+			break;
+		}
+	}
+	mutex_unlock(&bo->mappings.lock);
+
+	return mapping;
+}
+
+static void
+panfrost_gem_teardown_mapping(struct panfrost_gem_mapping *mapping)
+{
+	if (mapping->active)
+		panfrost_mmu_unmap(mapping);
+
+	spin_lock(&mapping->mmu->mm_lock);
+	if (drm_mm_node_allocated(&mapping->mmnode))
+		drm_mm_remove_node(&mapping->mmnode);
+	spin_unlock(&mapping->mmu->mm_lock);
+}
+
+static void panfrost_gem_mapping_release(struct kref *kref)
+{
+	struct panfrost_gem_mapping *mapping;
+
+	mapping = container_of(kref, struct panfrost_gem_mapping, refcount);
+
+	panfrost_gem_teardown_mapping(mapping);
+	drm_gem_object_put(&mapping->obj->base.base);
+	panfrost_mmu_ctx_put(mapping->mmu);
+	kfree(mapping);
+}
+
+void panfrost_gem_mapping_put(struct panfrost_gem_mapping *mapping)
+{
+	if (!mapping)
+		return;
+
+	kref_put(&mapping->refcount, panfrost_gem_mapping_release);
+}
+
+void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo)
+{
+	struct panfrost_gem_mapping *mapping;
+
+	list_for_each_entry(mapping, &bo->mappings.list, node)
+		panfrost_gem_teardown_mapping(mapping);
+}
+
+int panfrost_gem_open(struct drm_gem_object *obj, struct drm_file *file_priv)
+{
+	int ret;
+	size_t size = obj->size;
+	u64 align;
+	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
+	unsigned long color = bo->noexec ? PANFROST_BO_NOEXEC : 0;
+	struct panfrost_file_priv *priv = file_priv->driver_priv;
+	struct panfrost_gem_mapping *mapping;
+
+	mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
+	if (!mapping)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&mapping->node);
+	kref_init(&mapping->refcount);
+	drm_gem_object_get(obj);
+	mapping->obj = bo;
+
+	/*
+	 * Executable buffers cannot cross a 16MB boundary as the program
+	 * counter is 24-bits. We assume executable buffers will be less than
+	 * 16MB and aligning executable buffers to their size will avoid
+	 * crossing a 16MB boundary.
+	 */
+	if (!bo->noexec)
+		align = size >> PAGE_SHIFT;
+	else
+		align = size >= SZ_2M ? SZ_2M >> PAGE_SHIFT : 0;
+
+	mapping->mmu = panfrost_mmu_ctx_get(priv->mmu);
+	spin_lock(&mapping->mmu->mm_lock);
+	ret = drm_mm_insert_node_generic(&mapping->mmu->mm, &mapping->mmnode,
+					 size >> PAGE_SHIFT, align, color, 0);
+	spin_unlock(&mapping->mmu->mm_lock);
+	if (ret)
+		goto err;
+
+	if (!bo->is_heap) {
+		ret = panfrost_mmu_map(mapping);
+		if (ret)
+			goto err;
+	}
+
+	mutex_lock(&bo->mappings.lock);
+	WARN_ON(bo->base.madv != PANFROST_MADV_WILLNEED);
+	list_add_tail(&mapping->node, &bo->mappings.list);
+	mutex_unlock(&bo->mappings.lock);
+
+err:
+	if (ret)
+		panfrost_gem_mapping_put(mapping);
+	return ret;
+}
+
+void panfrost_gem_close(struct drm_gem_object *obj, struct drm_file *file_priv)
+{
+	struct panfrost_file_priv *priv = file_priv->driver_priv;
+	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
+	struct panfrost_gem_mapping *mapping = NULL, *iter;
+
+	mutex_lock(&bo->mappings.lock);
+	list_for_each_entry(iter, &bo->mappings.list, node) {
+		if (iter->mmu == priv->mmu) {
+			mapping = iter;
+			list_del(&iter->node);
+			break;
+		}
+	}
+	mutex_unlock(&bo->mappings.lock);
+
+	panfrost_gem_mapping_put(mapping);
+}
+
+static int panfrost_gem_pin(struct drm_gem_object *obj)
+{
+	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
+
+	if (bo->is_heap)
+		return -EINVAL;
+
+	return drm_gem_shmem_pin(&bo->base);
+}
+
+static const struct drm_gem_object_funcs panfrost_gem_funcs = {
+	.free = panfrost_gem_free_object,
+	.open = panfrost_gem_open,
+	.close = panfrost_gem_close,
+	.print_info = drm_gem_shmem_object_print_info,
+	.pin = panfrost_gem_pin,
+	.unpin = drm_gem_shmem_object_unpin,
+	.get_sg_table = drm_gem_shmem_object_get_sg_table,
+	.vmap = drm_gem_shmem_object_vmap,
+	.vunmap = drm_gem_shmem_object_vunmap,
+	.mmap = drm_gem_shmem_object_mmap,
+	.vm_ops = &drm_gem_shmem_vm_ops,
+};
+
+/**
+ * panfrost_gem_create_object - Implementation of driver->gem_create_object.
+ * @dev: DRM device
+ * @size: Size in bytes of the memory the object will reference
+ *
+ * This lets the GEM helpers allocate object structs for us, and keep
+ * our BO stats correct.
+ */
+struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t size)
+{
+	struct panfrost_device *pfdev = dev->dev_private;
+	struct panfrost_gem_object *obj;
+
+	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+	if (!obj)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&obj->mappings.list);
+	mutex_init(&obj->mappings.lock);
+	obj->base.base.funcs = &panfrost_gem_funcs;
+	obj->base.map_wc = !pfdev->coherent;
+
+	return &obj->base.base;
+}
+
+struct panfrost_gem_object *
+panfrost_gem_create(struct drm_device *dev, size_t size, u32 flags)
+{
+	struct drm_gem_shmem_object *shmem;
+	struct panfrost_gem_object *bo;
+
+	/* Round up heap allocations to 2MB to keep fault handling simple */
+	if (flags & PANFROST_BO_HEAP)
+		size = roundup(size, SZ_2M);
+
+	shmem = drm_gem_shmem_create(dev, size);
+	if (IS_ERR(shmem))
+		return ERR_CAST(shmem);
+
+	bo = to_panfrost_bo(&shmem->base);
+	bo->noexec = !!(flags & PANFROST_BO_NOEXEC);
+	bo->is_heap = !!(flags & PANFROST_BO_HEAP);
+
+	return bo;
+}
+
+struct drm_gem_object *
+panfrost_gem_prime_import_sg_table(struct drm_device *dev,
+				   struct dma_buf_attachment *attach,
+				   struct sg_table *sgt)
+{
+	struct drm_gem_object *obj;
+	struct panfrost_gem_object *bo;
+
+	obj = drm_gem_shmem_prime_import_sg_table(dev, attach, sgt);
+	if (IS_ERR(obj))
+		return ERR_CAST(obj);
+
+	bo = to_panfrost_bo(obj);
+	bo->noexec = true;
+
+	return obj;
+}