/* * drm gem CMA (contiguous memory allocator) helper functions * * Copyright (C) 2012 Sascha Hauer, Pengutronix * * Based on Samsung Exynos code * * Copyright (c) 2011 Samsung Electronics Co., Ltd. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/mm.h> #include <linux/slab.h> #include <linux/mutex.h> #include <linux/export.h> #include <linux/dma-buf.h> #include <linux/dma-mapping.h> #include <drm/drmP.h> #include <drm/drm.h> #include <drm/drm_gem_cma_helper.h> #include <drm/drm_vma_manager.h> /* * __drm_gem_cma_create - Create a GEM CMA object without allocating memory * @drm: The drm device * @size: The GEM object size * * This function creates and initializes a GEM CMA object of the given size, but * doesn't allocate any memory to back the object. * * Return a struct drm_gem_cma_object* on success or ERR_PTR values on failure. */ static struct drm_gem_cma_object * __drm_gem_cma_create(struct drm_device *drm, unsigned int size) { struct drm_gem_cma_object *cma_obj; struct drm_gem_object *gem_obj; int ret; cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL); if (!cma_obj) return ERR_PTR(-ENOMEM); gem_obj = &cma_obj->base; ret = drm_gem_object_init(drm, gem_obj, size); if (ret) goto error; ret = drm_gem_create_mmap_offset(gem_obj); if (ret) { drm_gem_object_release(gem_obj); goto error; } return cma_obj; error: kfree(cma_obj); return ERR_PTR(ret); } /* * drm_gem_cma_create - allocate an object with the given size * * returns a struct drm_gem_cma_object* on success or ERR_PTR values * on failure. */ struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm, unsigned int size) { struct drm_gem_cma_object *cma_obj; int ret; size = round_up(size, PAGE_SIZE); cma_obj = __drm_gem_cma_create(drm, size); if (IS_ERR(cma_obj)) return cma_obj; cma_obj->vaddr = dma_alloc_writecombine(drm->dev, size, &cma_obj->paddr, GFP_KERNEL | __GFP_NOWARN); if (!cma_obj->vaddr) { dev_err(drm->dev, "failed to allocate buffer with size %d\n", size); ret = -ENOMEM; goto error; } return cma_obj; error: drm_gem_cma_free_object(&cma_obj->base); return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(drm_gem_cma_create); /* * drm_gem_cma_create_with_handle - allocate an object with the given * size and create a gem handle on it * * returns a struct drm_gem_cma_object* on success or ERR_PTR values * on failure. */ static struct drm_gem_cma_object *drm_gem_cma_create_with_handle( struct drm_file *file_priv, struct drm_device *drm, unsigned int size, unsigned int *handle) { struct drm_gem_cma_object *cma_obj; struct drm_gem_object *gem_obj; int ret; cma_obj = drm_gem_cma_create(drm, size); if (IS_ERR(cma_obj)) return cma_obj; gem_obj = &cma_obj->base; /* * allocate a id of idr table where the obj is registered * and handle has the id what user can see. */ ret = drm_gem_handle_create(file_priv, gem_obj, handle); if (ret) goto err_handle_create; /* drop reference from allocate - handle holds it now. */ drm_gem_object_unreference_unlocked(gem_obj); return cma_obj; err_handle_create: drm_gem_cma_free_object(gem_obj); return ERR_PTR(ret); } /* * drm_gem_cma_free_object - (struct drm_driver)->gem_free_object callback * function */ void drm_gem_cma_free_object(struct drm_gem_object *gem_obj) { struct drm_gem_cma_object *cma_obj; drm_gem_free_mmap_offset(gem_obj); cma_obj = to_drm_gem_cma_obj(gem_obj); if (cma_obj->vaddr) { dma_free_writecombine(gem_obj->dev->dev, cma_obj->base.size, cma_obj->vaddr, cma_obj->paddr); } else if (gem_obj->import_attach) { drm_prime_gem_destroy(gem_obj, cma_obj->sgt); } drm_gem_object_release(gem_obj); kfree(cma_obj); } EXPORT_SYMBOL_GPL(drm_gem_cma_free_object); /* * drm_gem_cma_dumb_create - (struct drm_driver)->dumb_create callback * function * * This aligns the pitch and size arguments to the minimum required. wrap * this into your own function if you need bigger alignment. */ int drm_gem_cma_dumb_create(struct drm_file *file_priv, struct drm_device *dev, struct drm_mode_create_dumb *args) { struct drm_gem_cma_object *cma_obj; int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8); if (args->pitch < min_pitch) args->pitch = min_pitch; if (args->size < args->pitch * args->height) args->size = args->pitch * args->height; cma_obj = drm_gem_cma_create_with_handle(file_priv, dev, args->size, &args->handle); return PTR_ERR_OR_ZERO(cma_obj); } EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create); /* * drm_gem_cma_dumb_map_offset - (struct drm_driver)->dumb_map_offset callback * function */ int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv, struct drm_device *drm, uint32_t handle, uint64_t *offset) { struct drm_gem_object *gem_obj; mutex_lock(&drm->struct_mutex); gem_obj = drm_gem_object_lookup(drm, file_priv, handle); if (!gem_obj) { dev_err(drm->dev, "failed to lookup gem object\n"); mutex_unlock(&drm->struct_mutex); return -EINVAL; } *offset = drm_vma_node_offset_addr(&gem_obj->vma_node); drm_gem_object_unreference(gem_obj); mutex_unlock(&drm->struct_mutex); return 0; } EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset); const struct vm_operations_struct drm_gem_cma_vm_ops = { .open = drm_gem_vm_open, .close = drm_gem_vm_close, }; EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops); static int drm_gem_cma_mmap_obj(struct drm_gem_cma_object *cma_obj, struct vm_area_struct *vma) { int ret; /* * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map * the whole buffer. */ vma->vm_flags &= ~VM_PFNMAP; vma->vm_pgoff = 0; ret = dma_mmap_writecombine(cma_obj->base.dev->dev, vma, cma_obj->vaddr, cma_obj->paddr, vma->vm_end - vma->vm_start); if (ret) drm_gem_vm_close(vma); return ret; } /* * drm_gem_cma_mmap - (struct file_operation)->mmap callback function */ int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma) { struct drm_gem_cma_object *cma_obj; struct drm_gem_object *gem_obj; int ret; ret = drm_gem_mmap(filp, vma); if (ret) return ret; gem_obj = vma->vm_private_data; cma_obj = to_drm_gem_cma_obj(gem_obj); return drm_gem_cma_mmap_obj(cma_obj, vma); } EXPORT_SYMBOL_GPL(drm_gem_cma_mmap); #ifdef CONFIG_DEBUG_FS void drm_gem_cma_describe(struct drm_gem_cma_object *cma_obj, struct seq_file *m) { struct drm_gem_object *obj = &cma_obj->base; struct drm_device *dev = obj->dev; uint64_t off; WARN_ON(!mutex_is_locked(&dev->struct_mutex)); off = drm_vma_node_start(&obj->vma_node); seq_printf(m, "%2d (%2d) %08llx %pad %p %d", obj->name, obj->refcount.refcount.counter, off, &cma_obj->paddr, cma_obj->vaddr, obj->size); seq_printf(m, "\n"); } EXPORT_SYMBOL_GPL(drm_gem_cma_describe); #endif /* low-level interface prime helpers */ struct sg_table *drm_gem_cma_prime_get_sg_table(struct drm_gem_object *obj) { struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); struct sg_table *sgt; int ret; sgt = kzalloc(sizeof(*sgt), GFP_KERNEL); if (!sgt) return NULL; ret = dma_get_sgtable(obj->dev->dev, sgt, cma_obj->vaddr, cma_obj->paddr, obj->size); if (ret < 0) goto out; return sgt; out: kfree(sgt); return NULL; } EXPORT_SYMBOL_GPL(drm_gem_cma_prime_get_sg_table); struct drm_gem_object * drm_gem_cma_prime_import_sg_table(struct drm_device *dev, size_t size, struct sg_table *sgt) { struct drm_gem_cma_object *cma_obj; if (sgt->nents != 1) return ERR_PTR(-EINVAL); /* Create a CMA GEM buffer. */ cma_obj = __drm_gem_cma_create(dev, size); if (IS_ERR(cma_obj)) return ERR_PTR(PTR_ERR(cma_obj)); cma_obj->paddr = sg_dma_address(sgt->sgl); cma_obj->sgt = sgt; DRM_DEBUG_PRIME("dma_addr = %pad, size = %zu\n", &cma_obj->paddr, size); return &cma_obj->base; } EXPORT_SYMBOL_GPL(drm_gem_cma_prime_import_sg_table); int drm_gem_cma_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) { struct drm_gem_cma_object *cma_obj; struct drm_device *dev = obj->dev; int ret; mutex_lock(&dev->struct_mutex); ret = drm_gem_mmap_obj(obj, obj->size, vma); mutex_unlock(&dev->struct_mutex); if (ret < 0) return ret; cma_obj = to_drm_gem_cma_obj(obj); return drm_gem_cma_mmap_obj(cma_obj, vma); } EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap); void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj) { struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); return cma_obj->vaddr; } EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap); void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr) { /* Nothing to do */ } EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap);