1 files changed, 389 insertions, 0 deletions
diff --git a/drivers/gpu/drm/v3d/v3d_bo.c b/drivers/gpu/drm/v3d/v3d_bo.c
new file mode 100644
index 000000000000..7b1e2a549a71
--- /dev/null
+++ b/drivers/gpu/drm/v3d/v3d_bo.c
@@ -0,0 +1,389 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (C) 2015-2018 Broadcom */
+
+/**
+ * DOC: V3D GEM BO management support
+ *
+ * Compared to VC4 (V3D 2.x), V3D 3.3 introduces an MMU between the
+ * GPU and the bus, allowing us to use shmem objects for our storage
+ * instead of CMA.
+ *
+ * Physically contiguous objects may still be imported to V3D, but the
+ * driver doesn't allocate physically contiguous objects on its own.
+ * Display engines requiring physically contiguous allocations should
+ * look into Mesa's "renderonly" support (as used by the Mesa pl111
+ * driver) for an example of how to integrate with V3D.
+ *
+ * Long term, we should support evicting pages from the MMU when under
+ * memory pressure (thus the v3d_bo_get_pages() refcounting), but
+ * that's not a high priority since our systems tend to not have swap.
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/pfn_t.h>
+
+#include "v3d_drv.h"
+#include "uapi/drm/v3d_drm.h"
+
+/* Pins the shmem pages, fills in the .pages and .sgt fields of the BO, and maps
+ * it for DMA.
+ */
+static int
+v3d_bo_get_pages(struct v3d_bo *bo)
+{
+	struct drm_gem_object *obj = &bo->base;
+	struct drm_device *dev = obj->dev;
+	int npages = obj->size >> PAGE_SHIFT;
+	int ret = 0;
+
+	mutex_lock(&bo->lock);
+	if (bo->pages_refcount++ != 0)
+		goto unlock;
+
+	if (!obj->import_attach) {
+		bo->pages = drm_gem_get_pages(obj);
+		if (IS_ERR(bo->pages)) {
+			ret = PTR_ERR(bo->pages);
+			goto unlock;
+		}
+
+		bo->sgt = drm_prime_pages_to_sg(bo->pages, npages);
+		if (IS_ERR(bo->sgt)) {
+			ret = PTR_ERR(bo->sgt);
+			goto put_pages;
+		}
+
+		/* Map the pages for use by the GPU. */
+		dma_map_sg(dev->dev, bo->sgt->sgl,
+			   bo->sgt->nents, DMA_BIDIRECTIONAL);
+	} else {
+		bo->pages = kcalloc(npages, sizeof(*bo->pages), GFP_KERNEL);
+		if (!bo->pages)
+			goto put_pages;
+
+		drm_prime_sg_to_page_addr_arrays(bo->sgt, bo->pages,
+						 NULL, npages);
+
+		/* Note that dma-bufs come in mapped. */
+	}
+
+	mutex_unlock(&bo->lock);
+
+	return 0;
+
+put_pages:
+	drm_gem_put_pages(obj, bo->pages, true, true);
+	bo->pages = NULL;
+unlock:
+	bo->pages_refcount--;
+	mutex_unlock(&bo->lock);
+	return ret;
+}
+
+static void
+v3d_bo_put_pages(struct v3d_bo *bo)
+{
+	struct drm_gem_object *obj = &bo->base;
+
+	mutex_lock(&bo->lock);
+	if (--bo->pages_refcount == 0) {
+		if (!obj->import_attach) {
+			dma_unmap_sg(obj->dev->dev, bo->sgt->sgl,
+				     bo->sgt->nents, DMA_BIDIRECTIONAL);
+			sg_free_table(bo->sgt);
+			kfree(bo->sgt);
+			drm_gem_put_pages(obj, bo->pages, true, true);
+		} else {
+			kfree(bo->pages);
+		}
+	}
+	mutex_unlock(&bo->lock);
+}
+
+static struct v3d_bo *v3d_bo_create_struct(struct drm_device *dev,
+					   size_t unaligned_size)
+{
+	struct v3d_dev *v3d = to_v3d_dev(dev);
+	struct drm_gem_object *obj;
+	struct v3d_bo *bo;
+	size_t size = roundup(unaligned_size, PAGE_SIZE);
+	int ret;
+
+	if (size == 0)
+		return ERR_PTR(-EINVAL);
+
+	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
+	if (!bo)
+		return ERR_PTR(-ENOMEM);
+	obj = &bo->base;
+
+	INIT_LIST_HEAD(&bo->vmas);
+	INIT_LIST_HEAD(&bo->unref_head);
+	mutex_init(&bo->lock);
+
+	ret = drm_gem_object_init(dev, obj, size);
+	if (ret)
+		goto free_bo;
+
+	spin_lock(&v3d->mm_lock);
+	ret = drm_mm_insert_node_generic(&v3d->mm, &bo->node,
+					 obj->size >> PAGE_SHIFT,
+					 GMP_GRANULARITY >> PAGE_SHIFT, 0, 0);
+	spin_unlock(&v3d->mm_lock);
+	if (ret)
+		goto free_obj;
+
+	return bo;
+
+free_obj:
+	drm_gem_object_release(obj);
+free_bo:
+	kfree(bo);
+	return ERR_PTR(ret);
+}
+
+struct v3d_bo *v3d_bo_create(struct drm_device *dev, struct drm_file *file_priv,
+			     size_t unaligned_size)
+{
+	struct v3d_dev *v3d = to_v3d_dev(dev);
+	struct drm_gem_object *obj;
+	struct v3d_bo *bo;
+	int ret;
+
+	bo = v3d_bo_create_struct(dev, unaligned_size);
+	if (IS_ERR(bo))
+		return bo;
+	obj = &bo->base;
+
+	bo->resv = &bo->_resv;
+	reservation_object_init(bo->resv);
+
+	ret = v3d_bo_get_pages(bo);
+	if (ret)
+		goto free_mm;
+
+	v3d_mmu_insert_ptes(bo);
+
+	mutex_lock(&v3d->bo_lock);
+	v3d->bo_stats.num_allocated++;
+	v3d->bo_stats.pages_allocated += obj->size >> PAGE_SHIFT;
+	mutex_unlock(&v3d->bo_lock);
+
+	return bo;
+
+free_mm:
+	spin_lock(&v3d->mm_lock);
+	drm_mm_remove_node(&bo->node);
+	spin_unlock(&v3d->mm_lock);
+
+	drm_gem_object_release(obj);
+	kfree(bo);
+	return ERR_PTR(ret);
+}
+
+/* Called DRM core on the last userspace/kernel unreference of the
+ * BO.
+ */
+void v3d_free_object(struct drm_gem_object *obj)
+{
+	struct v3d_dev *v3d = to_v3d_dev(obj->dev);
+	struct v3d_bo *bo = to_v3d_bo(obj);
+
+	mutex_lock(&v3d->bo_lock);
+	v3d->bo_stats.num_allocated--;
+	v3d->bo_stats.pages_allocated -= obj->size >> PAGE_SHIFT;
+	mutex_unlock(&v3d->bo_lock);
+
+	reservation_object_fini(&bo->_resv);
+
+	v3d_bo_put_pages(bo);
+
+	if (obj->import_attach)
+		drm_prime_gem_destroy(obj, bo->sgt);
+
+	v3d_mmu_remove_ptes(bo);
+	spin_lock(&v3d->mm_lock);
+	drm_mm_remove_node(&bo->node);
+	spin_unlock(&v3d->mm_lock);
+
+	mutex_destroy(&bo->lock);
+
+	drm_gem_object_release(obj);
+	kfree(bo);
+}
+
+struct reservation_object *v3d_prime_res_obj(struct drm_gem_object *obj)
+{
+	struct v3d_bo *bo = to_v3d_bo(obj);
+
+	return bo->resv;
+}
+
+static void
+v3d_set_mmap_vma_flags(struct vm_area_struct *vma)
+{
+	vma->vm_flags &= ~VM_PFNMAP;
+	vma->vm_flags |= VM_MIXEDMAP;
+	vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
+}
+
+int v3d_gem_fault(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+	struct drm_gem_object *obj = vma->vm_private_data;
+	struct v3d_bo *bo = to_v3d_bo(obj);
+	unsigned long pfn;
+	pgoff_t pgoff;
+	int ret;
+
+	/* We don't use vmf->pgoff since that has the fake offset: */
+	pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
+	pfn = page_to_pfn(bo->pages[pgoff]);
+
+	ret = vm_insert_mixed(vma, vmf->address, __pfn_to_pfn_t(pfn, PFN_DEV));
+
+	switch (ret) {
+	case -EAGAIN:
+	case 0:
+	case -ERESTARTSYS:
+	case -EINTR:
+	case -EBUSY:
+		/*
+		 * EBUSY is ok: this just means that another thread
+		 * already did the job.
+		 */
+		return VM_FAULT_NOPAGE;
+	case -ENOMEM:
+		return VM_FAULT_OOM;
+	default:
+		return VM_FAULT_SIGBUS;
+	}
+}
+
+int v3d_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	int ret;
+
+	ret = drm_gem_mmap(filp, vma);
+	if (ret)
+		return ret;
+
+	v3d_set_mmap_vma_flags(vma);
+
+	return ret;
+}
+
+int v3d_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
+{
+	int ret;
+
+	ret = drm_gem_mmap_obj(obj, obj->size, vma);
+	if (ret < 0)
+		return ret;
+
+	v3d_set_mmap_vma_flags(vma);
+
+	return 0;
+}
+
+struct sg_table *
+v3d_prime_get_sg_table(struct drm_gem_object *obj)
+{
+	struct v3d_bo *bo = to_v3d_bo(obj);
+	int npages = obj->size >> PAGE_SHIFT;
+
+	return drm_prime_pages_to_sg(bo->pages, npages);
+}
+
+struct drm_gem_object *
+v3d_prime_import_sg_table(struct drm_device *dev,
+			  struct dma_buf_attachment *attach,
+			  struct sg_table *sgt)
+{
+	struct drm_gem_object *obj;
+	struct v3d_bo *bo;
+
+	bo = v3d_bo_create_struct(dev, attach->dmabuf->size);
+	if (IS_ERR(bo))
+		return ERR_CAST(bo);
+	obj = &bo->base;
+
+	bo->resv = attach->dmabuf->resv;
+
+	bo->sgt = sgt;
+	v3d_bo_get_pages(bo);
+
+	v3d_mmu_insert_ptes(bo);
+
+	return obj;
+}
+
+int v3d_create_bo_ioctl(struct drm_device *dev, void *data,
+			struct drm_file *file_priv)
+{
+	struct drm_v3d_create_bo *args = data;
+	struct v3d_bo *bo = NULL;
+	int ret;
+
+	if (args->flags != 0) {
+		DRM_INFO("unknown create_bo flags: %d\n", args->flags);
+		return -EINVAL;
+	}
+
+	bo = v3d_bo_create(dev, file_priv, PAGE_ALIGN(args->size));
+	if (IS_ERR(bo))
+		return PTR_ERR(bo);
+
+	args->offset = bo->node.start << PAGE_SHIFT;
+
+	ret = drm_gem_handle_create(file_priv, &bo->base, &args->handle);
+	drm_gem_object_put_unlocked(&bo->base);
+
+	return ret;
+}
+
+int v3d_mmap_bo_ioctl(struct drm_device *dev, void *data,
+		      struct drm_file *file_priv)
+{
+	struct drm_v3d_mmap_bo *args = data;
+	struct drm_gem_object *gem_obj;
+	int ret;
+
+	if (args->flags != 0) {
+		DRM_INFO("unknown mmap_bo flags: %d\n", args->flags);
+		return -EINVAL;
+	}
+
+	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
+	if (!gem_obj) {
+		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
+		return -ENOENT;
+	}
+
+	ret = drm_gem_create_mmap_offset(gem_obj);
+	if (ret == 0)
+		args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
+	drm_gem_object_put_unlocked(gem_obj);
+
+	return ret;
+}
+
+int v3d_get_bo_offset_ioctl(struct drm_device *dev, void *data,
+			    struct drm_file *file_priv)
+{
+	struct drm_v3d_get_bo_offset *args = data;
+	struct drm_gem_object *gem_obj;
+	struct v3d_bo *bo;
+
+	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
+	if (!gem_obj) {
+		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
+		return -ENOENT;
+	}
+	bo = to_v3d_bo(gem_obj);
+
+	args->offset = bo->node.start << PAGE_SHIFT;
+
+	drm_gem_object_put_unlocked(gem_obj);
+	return 0;
+}