From b22b51a0346ed64b781122a4db3824cd400e9f57 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Tue, 31 Mar 2020 10:12:38 +0200 Subject: drm/vram-helpers: Merge code into a single file Most of the documentation was in an otherwise empty file, which was probably just left from a previous clean-up effort. So move code and documentation into a single file. Signed-off-by: Thomas Zimmermann Acked-by: Gerd Hoffmann Acked-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200331081238.24749-1-tzimmermann@suse.de --- drivers/gpu/drm/drm_vram_helper_common.c | 94 -------------------------------- 1 file changed, 94 deletions(-) delete mode 100644 drivers/gpu/drm/drm_vram_helper_common.c (limited to 'drivers/gpu/drm/drm_vram_helper_common.c') diff --git a/drivers/gpu/drm/drm_vram_helper_common.c b/drivers/gpu/drm/drm_vram_helper_common.c deleted file mode 100644 index 2000d9b33fd5..000000000000 --- a/drivers/gpu/drm/drm_vram_helper_common.c +++ /dev/null @@ -1,94 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later - -#include - -/** - * DOC: overview - * - * This library provides &struct drm_gem_vram_object (GEM VRAM), a GEM - * buffer object that is backed by video RAM. It can be used for - * framebuffer devices with dedicated memory. The video RAM is managed - * by &struct drm_vram_mm (VRAM MM). - * - * With the GEM interface userspace applications create, manage and destroy - * graphics buffers, such as an on-screen framebuffer. GEM does not provide - * an implementation of these interfaces. It's up to the DRM driver to - * provide an implementation that suits the hardware. If the hardware device - * contains dedicated video memory, the DRM driver can use the VRAM helper - * library. Each active buffer object is stored in video RAM. Active - * buffer are used for drawing the current frame, typically something like - * the frame's scanout buffer or the cursor image. If there's no more space - * left in VRAM, inactive GEM objects can be moved to system memory. - * - * The easiest way to use the VRAM helper library is to call - * drm_vram_helper_alloc_mm(). The function allocates and initializes an - * instance of &struct drm_vram_mm in &struct drm_device.vram_mm . Use - * &DRM_GEM_VRAM_DRIVER to initialize &struct drm_driver and - * &DRM_VRAM_MM_FILE_OPERATIONS to initialize &struct file_operations; - * as illustrated below. - * - * .. code-block:: c - * - * struct file_operations fops ={ - * .owner = THIS_MODULE, - * DRM_VRAM_MM_FILE_OPERATION - * }; - * struct drm_driver drv = { - * .driver_feature = DRM_ ... , - * .fops = &fops, - * DRM_GEM_VRAM_DRIVER - * }; - * - * int init_drm_driver() - * { - * struct drm_device *dev; - * uint64_t vram_base; - * unsigned long vram_size; - * int ret; - * - * // setup device, vram base and size - * // ... - * - * ret = drm_vram_helper_alloc_mm(dev, vram_base, vram_size); - * if (ret) - * return ret; - * return 0; - * } - * - * This creates an instance of &struct drm_vram_mm, exports DRM userspace - * interfaces for GEM buffer management and initializes file operations to - * allow for accessing created GEM buffers. With this setup, the DRM driver - * manages an area of video RAM with VRAM MM and provides GEM VRAM objects - * to userspace. - * - * To clean up the VRAM memory management, call drm_vram_helper_release_mm() - * in the driver's clean-up code. - * - * .. code-block:: c - * - * void fini_drm_driver() - * { - * struct drm_device *dev = ...; - * - * drm_vram_helper_release_mm(dev); - * } - * - * For drawing or scanout operations, buffer object have to be pinned in video - * RAM. Call drm_gem_vram_pin() with &DRM_GEM_VRAM_PL_FLAG_VRAM or - * &DRM_GEM_VRAM_PL_FLAG_SYSTEM to pin a buffer object in video RAM or system - * memory. Call drm_gem_vram_unpin() to release the pinned object afterwards. - * - * A buffer object that is pinned in video RAM has a fixed address within that - * memory region. Call drm_gem_vram_offset() to retrieve this value. Typically - * it's used to program the hardware's scanout engine for framebuffers, set - * the cursor overlay's image for a mouse cursor, or use it as input to the - * hardware's draing engine. - * - * To access a buffer object's memory from the DRM driver, call - * drm_gem_vram_kmap(). It (optionally) maps the buffer into kernel address - * space and returns the memory address. Use drm_gem_vram_kunmap() to - * release the mapping. - */ - -MODULE_DESCRIPTION("DRM VRAM memory-management helpers"); -MODULE_LICENSE("GPL"); -- cgit v1.2.3