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1// SPDX-License-Identifier: MIT2 3#include <linux/fb.h>4 5#include <drm/drm_crtc_helper.h>6#include <drm/drm_drv.h>7#include <drm/drm_fb_helper.h>8#include <drm/drm_framebuffer.h>9#include <drm/drm_gem_framebuffer_helper.h>10#include <drm/drm_gem_shmem_helper.h>11 12#include <drm/drm_fbdev_shmem.h>13 14/*15 * struct fb_ops16 */17 18static int drm_fbdev_shmem_fb_open(struct fb_info *info, int user)19{20 struct drm_fb_helper *fb_helper = info->par;21 22 /* No need to take a ref for fbcon because it unbinds on unregister */23 if (user && !try_module_get(fb_helper->dev->driver->fops->owner))24 return -ENODEV;25 26 return 0;27}28 29static int drm_fbdev_shmem_fb_release(struct fb_info *info, int user)30{31 struct drm_fb_helper *fb_helper = info->par;32 33 if (user)34 module_put(fb_helper->dev->driver->fops->owner);35 36 return 0;37}38 39FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(drm_fbdev_shmem,40 drm_fb_helper_damage_range,41 drm_fb_helper_damage_area);42 43static int drm_fbdev_shmem_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)44{45 struct drm_fb_helper *fb_helper = info->par;46 struct drm_framebuffer *fb = fb_helper->fb;47 struct drm_gem_object *obj = drm_gem_fb_get_obj(fb, 0);48 struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);49 50 if (shmem->map_wc)51 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);52 53 return fb_deferred_io_mmap(info, vma);54}55 56static void drm_fbdev_shmem_fb_destroy(struct fb_info *info)57{58 struct drm_fb_helper *fb_helper = info->par;59 60 if (!fb_helper->dev)61 return;62 63 fb_deferred_io_cleanup(info);64 drm_fb_helper_fini(fb_helper);65 66 drm_client_buffer_vunmap(fb_helper->buffer);67 drm_client_framebuffer_delete(fb_helper->buffer);68 drm_client_release(&fb_helper->client);69 drm_fb_helper_unprepare(fb_helper);70 kfree(fb_helper);71}72 73static const struct fb_ops drm_fbdev_shmem_fb_ops = {74 .owner = THIS_MODULE,75 .fb_open = drm_fbdev_shmem_fb_open,76 .fb_release = drm_fbdev_shmem_fb_release,77 __FB_DEFAULT_DEFERRED_OPS_RDWR(drm_fbdev_shmem),78 DRM_FB_HELPER_DEFAULT_OPS,79 __FB_DEFAULT_DEFERRED_OPS_DRAW(drm_fbdev_shmem),80 .fb_mmap = drm_fbdev_shmem_fb_mmap,81 .fb_destroy = drm_fbdev_shmem_fb_destroy,82};83 84static struct page *drm_fbdev_shmem_get_page(struct fb_info *info, unsigned long offset)85{86 struct drm_fb_helper *fb_helper = info->par;87 struct drm_framebuffer *fb = fb_helper->fb;88 struct drm_gem_object *obj = drm_gem_fb_get_obj(fb, 0);89 struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);90 unsigned int i = offset >> PAGE_SHIFT;91 struct page *page;92 93 if (fb_WARN_ON_ONCE(info, offset > obj->size))94 return NULL;95 96 page = shmem->pages[i]; // protected by active vmap97 if (page)98 get_page(page);99 fb_WARN_ON_ONCE(info, !page);100 101 return page;102}103 104/*105 * struct drm_fb_helper106 */107 108static int drm_fbdev_shmem_helper_fb_probe(struct drm_fb_helper *fb_helper,109 struct drm_fb_helper_surface_size *sizes)110{111 struct drm_client_dev *client = &fb_helper->client;112 struct drm_device *dev = fb_helper->dev;113 struct drm_client_buffer *buffer;114 struct drm_gem_shmem_object *shmem;115 struct drm_framebuffer *fb;116 struct fb_info *info;117 u32 format;118 struct iosys_map map;119 int ret;120 121 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",122 sizes->surface_width, sizes->surface_height,123 sizes->surface_bpp);124 125 format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp, sizes->surface_depth);126 buffer = drm_client_framebuffer_create(client, sizes->surface_width,127 sizes->surface_height, format);128 if (IS_ERR(buffer))129 return PTR_ERR(buffer);130 shmem = to_drm_gem_shmem_obj(buffer->gem);131 132 fb = buffer->fb;133 134 ret = drm_client_buffer_vmap(buffer, &map);135 if (ret) {136 goto err_drm_client_buffer_delete;137 } else if (drm_WARN_ON(dev, map.is_iomem)) {138 ret = -ENODEV; /* I/O memory not supported; use generic emulation */139 goto err_drm_client_buffer_delete;140 }141 142 fb_helper->buffer = buffer;143 fb_helper->fb = fb;144 145 info = drm_fb_helper_alloc_info(fb_helper);146 if (IS_ERR(info)) {147 ret = PTR_ERR(info);148 goto err_drm_client_buffer_vunmap;149 }150 151 drm_fb_helper_fill_info(info, fb_helper, sizes);152 153 info->fbops = &drm_fbdev_shmem_fb_ops;154 155 /* screen */156 info->flags |= FBINFO_VIRTFB; /* system memory */157 if (!shmem->map_wc)158 info->flags |= FBINFO_READS_FAST; /* signal caching */159 info->screen_size = sizes->surface_height * fb->pitches[0];160 info->screen_buffer = map.vaddr;161 info->fix.smem_len = info->screen_size;162 163 /* deferred I/O */164 fb_helper->fbdefio.delay = HZ / 20;165 fb_helper->fbdefio.get_page = drm_fbdev_shmem_get_page;166 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;167 168 info->fbdefio = &fb_helper->fbdefio;169 ret = fb_deferred_io_init(info);170 if (ret)171 goto err_drm_fb_helper_release_info;172 173 return 0;174 175err_drm_fb_helper_release_info:176 drm_fb_helper_release_info(fb_helper);177err_drm_client_buffer_vunmap:178 fb_helper->fb = NULL;179 fb_helper->buffer = NULL;180 drm_client_buffer_vunmap(buffer);181err_drm_client_buffer_delete:182 drm_client_framebuffer_delete(buffer);183 return ret;184}185 186static int drm_fbdev_shmem_helper_fb_dirty(struct drm_fb_helper *helper,187 struct drm_clip_rect *clip)188{189 struct drm_device *dev = helper->dev;190 int ret;191 192 /* Call damage handlers only if necessary */193 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))194 return 0;195 196 if (helper->fb->funcs->dirty) {197 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);198 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))199 return ret;200 }201 202 return 0;203}204 205static const struct drm_fb_helper_funcs drm_fbdev_shmem_helper_funcs = {206 .fb_probe = drm_fbdev_shmem_helper_fb_probe,207 .fb_dirty = drm_fbdev_shmem_helper_fb_dirty,208};209 210/*211 * struct drm_client_funcs212 */213 214static void drm_fbdev_shmem_client_unregister(struct drm_client_dev *client)215{216 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);217 218 if (fb_helper->info) {219 drm_fb_helper_unregister_info(fb_helper);220 } else {221 drm_client_release(&fb_helper->client);222 drm_fb_helper_unprepare(fb_helper);223 kfree(fb_helper);224 }225}226 227static int drm_fbdev_shmem_client_restore(struct drm_client_dev *client)228{229 drm_fb_helper_lastclose(client->dev);230 231 return 0;232}233 234static int drm_fbdev_shmem_client_hotplug(struct drm_client_dev *client)235{236 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);237 struct drm_device *dev = client->dev;238 int ret;239 240 if (dev->fb_helper)241 return drm_fb_helper_hotplug_event(dev->fb_helper);242 243 ret = drm_fb_helper_init(dev, fb_helper);244 if (ret)245 goto err_drm_err;246 247 if (!drm_drv_uses_atomic_modeset(dev))248 drm_helper_disable_unused_functions(dev);249 250 ret = drm_fb_helper_initial_config(fb_helper);251 if (ret)252 goto err_drm_fb_helper_fini;253 254 return 0;255 256err_drm_fb_helper_fini:257 drm_fb_helper_fini(fb_helper);258err_drm_err:259 drm_err(dev, "fbdev-shmem: Failed to setup emulation (ret=%d)\n", ret);260 return ret;261}262 263static const struct drm_client_funcs drm_fbdev_shmem_client_funcs = {264 .owner = THIS_MODULE,265 .unregister = drm_fbdev_shmem_client_unregister,266 .restore = drm_fbdev_shmem_client_restore,267 .hotplug = drm_fbdev_shmem_client_hotplug,268};269 270/**271 * drm_fbdev_shmem_setup() - Setup fbdev emulation for GEM SHMEM helpers272 * @dev: DRM device273 * @preferred_bpp: Preferred bits per pixel for the device.274 * 32 is used if this is zero.275 *276 * This function sets up fbdev emulation for GEM DMA drivers that support277 * dumb buffers with a virtual address and that can be mmap'ed.278 * drm_fbdev_shmem_setup() shall be called after the DRM driver registered279 * the new DRM device with drm_dev_register().280 *281 * Restore, hotplug events and teardown are all taken care of. Drivers that do282 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.283 * Simple drivers might use drm_mode_config_helper_suspend().284 *285 * This function is safe to call even when there are no connectors present.286 * Setup will be retried on the next hotplug event.287 *288 * The fbdev is destroyed by drm_dev_unregister().289 */290void drm_fbdev_shmem_setup(struct drm_device *dev, unsigned int preferred_bpp)291{292 struct drm_fb_helper *fb_helper;293 int ret;294 295 drm_WARN(dev, !dev->registered, "Device has not been registered.\n");296 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");297 298 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);299 if (!fb_helper)300 return;301 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_shmem_helper_funcs);302 303 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_shmem_client_funcs);304 if (ret) {305 drm_err(dev, "Failed to register client: %d\n", ret);306 goto err_drm_client_init;307 }308 309 drm_client_register(&fb_helper->client);310 311 return;312 313err_drm_client_init:314 drm_fb_helper_unprepare(fb_helper);315 kfree(fb_helper);316}317EXPORT_SYMBOL(drm_fbdev_shmem_setup);318