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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_dma_helper.h>8#include <drm/drm_fb_helper.h>9#include <drm/drm_framebuffer.h>10#include <drm/drm_gem_dma_helper.h>11 12#include <drm/drm_fbdev_dma.h>13 14/*15 * struct fb_ops16 */17 18static int drm_fbdev_dma_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_dma_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 39static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)40{41 struct drm_fb_helper *fb_helper = info->par;42 43 return drm_gem_prime_mmap(fb_helper->buffer->gem, vma);44}45 46static void drm_fbdev_dma_fb_destroy(struct fb_info *info)47{48 struct drm_fb_helper *fb_helper = info->par;49 50 if (!fb_helper->dev)51 return;52 53 if (info->fbdefio)54 fb_deferred_io_cleanup(info);55 drm_fb_helper_fini(fb_helper);56 57 drm_client_buffer_vunmap(fb_helper->buffer);58 drm_client_framebuffer_delete(fb_helper->buffer);59 drm_client_release(&fb_helper->client);60 drm_fb_helper_unprepare(fb_helper);61 kfree(fb_helper);62}63 64static const struct fb_ops drm_fbdev_dma_fb_ops = {65 .owner = THIS_MODULE,66 .fb_open = drm_fbdev_dma_fb_open,67 .fb_release = drm_fbdev_dma_fb_release,68 __FB_DEFAULT_DMAMEM_OPS_RDWR,69 DRM_FB_HELPER_DEFAULT_OPS,70 __FB_DEFAULT_DMAMEM_OPS_DRAW,71 .fb_mmap = drm_fbdev_dma_fb_mmap,72 .fb_destroy = drm_fbdev_dma_fb_destroy,73};74 75FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(drm_fbdev_dma,76 drm_fb_helper_damage_range,77 drm_fb_helper_damage_area);78 79static int drm_fbdev_dma_deferred_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)80{81 struct drm_fb_helper *fb_helper = info->par;82 struct drm_framebuffer *fb = fb_helper->fb;83 struct drm_gem_dma_object *dma = drm_fb_dma_get_gem_obj(fb, 0);84 85 if (!dma->map_noncoherent)86 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);87 88 return fb_deferred_io_mmap(info, vma);89}90 91static const struct fb_ops drm_fbdev_dma_deferred_fb_ops = {92 .owner = THIS_MODULE,93 .fb_open = drm_fbdev_dma_fb_open,94 .fb_release = drm_fbdev_dma_fb_release,95 __FB_DEFAULT_DEFERRED_OPS_RDWR(drm_fbdev_dma),96 DRM_FB_HELPER_DEFAULT_OPS,97 __FB_DEFAULT_DEFERRED_OPS_DRAW(drm_fbdev_dma),98 .fb_mmap = drm_fbdev_dma_deferred_fb_mmap,99 .fb_destroy = drm_fbdev_dma_fb_destroy,100};101 102/*103 * struct drm_fb_helper104 */105 106static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper,107 struct drm_fb_helper_surface_size *sizes)108{109 struct drm_client_dev *client = &fb_helper->client;110 struct drm_device *dev = fb_helper->dev;111 bool use_deferred_io = false;112 struct drm_client_buffer *buffer;113 struct drm_gem_dma_object *dma_obj;114 struct drm_framebuffer *fb;115 struct fb_info *info;116 u32 format;117 struct iosys_map map;118 int ret;119 120 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",121 sizes->surface_width, sizes->surface_height,122 sizes->surface_bpp);123 124 format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp,125 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 dma_obj = to_drm_gem_dma_obj(buffer->gem);131 132 fb = buffer->fb;133 134 /*135 * Deferred I/O requires struct page for framebuffer memory,136 * which is not guaranteed for all DMA ranges. We thus only137 * install deferred I/O if we have a framebuffer that requires138 * it.139 */140 if (fb->funcs->dirty)141 use_deferred_io = true;142 143 ret = drm_client_buffer_vmap(buffer, &map);144 if (ret) {145 goto err_drm_client_buffer_delete;146 } else if (drm_WARN_ON(dev, map.is_iomem)) {147 ret = -ENODEV; /* I/O memory not supported; use generic emulation */148 goto err_drm_client_buffer_delete;149 }150 151 fb_helper->buffer = buffer;152 fb_helper->fb = fb;153 154 info = drm_fb_helper_alloc_info(fb_helper);155 if (IS_ERR(info)) {156 ret = PTR_ERR(info);157 goto err_drm_client_buffer_vunmap;158 }159 160 drm_fb_helper_fill_info(info, fb_helper, sizes);161 162 if (use_deferred_io)163 info->fbops = &drm_fbdev_dma_deferred_fb_ops;164 else165 info->fbops = &drm_fbdev_dma_fb_ops;166 167 /* screen */168 info->flags |= FBINFO_VIRTFB; /* system memory */169 if (dma_obj->map_noncoherent)170 info->flags |= FBINFO_READS_FAST; /* signal caching */171 info->screen_size = sizes->surface_height * fb->pitches[0];172 info->screen_buffer = map.vaddr;173 if (!(info->flags & FBINFO_HIDE_SMEM_START)) {174 if (!drm_WARN_ON(dev, is_vmalloc_addr(info->screen_buffer)))175 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));176 }177 info->fix.smem_len = info->screen_size;178 179 /*180 * Only set up deferred I/O if the screen buffer supports181 * it. If this disagrees with the previous test for ->dirty,182 * mmap on the /dev/fb file might not work correctly.183 */184 if (!is_vmalloc_addr(info->screen_buffer) && info->fix.smem_start) {185 unsigned long pfn = info->fix.smem_start >> PAGE_SHIFT;186 187 if (drm_WARN_ON(dev, !pfn_to_page(pfn)))188 use_deferred_io = false;189 }190 191 /* deferred I/O */192 if (use_deferred_io) {193 fb_helper->fbdefio.delay = HZ / 20;194 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;195 196 info->fbdefio = &fb_helper->fbdefio;197 ret = fb_deferred_io_init(info);198 if (ret)199 goto err_drm_fb_helper_release_info;200 }201 202 return 0;203 204err_drm_fb_helper_release_info:205 drm_fb_helper_release_info(fb_helper);206err_drm_client_buffer_vunmap:207 fb_helper->fb = NULL;208 fb_helper->buffer = NULL;209 drm_client_buffer_vunmap(buffer);210err_drm_client_buffer_delete:211 drm_client_framebuffer_delete(buffer);212 return ret;213}214 215static int drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper *helper,216 struct drm_clip_rect *clip)217{218 struct drm_device *dev = helper->dev;219 int ret;220 221 /* Call damage handlers only if necessary */222 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))223 return 0;224 225 if (helper->fb->funcs->dirty) {226 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);227 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))228 return ret;229 }230 231 return 0;232}233 234static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = {235 .fb_probe = drm_fbdev_dma_helper_fb_probe,236 .fb_dirty = drm_fbdev_dma_helper_fb_dirty,237};238 239/*240 * struct drm_client_funcs241 */242 243static void drm_fbdev_dma_client_unregister(struct drm_client_dev *client)244{245 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);246 247 if (fb_helper->info) {248 drm_fb_helper_unregister_info(fb_helper);249 } else {250 drm_client_release(&fb_helper->client);251 drm_fb_helper_unprepare(fb_helper);252 kfree(fb_helper);253 }254}255 256static int drm_fbdev_dma_client_restore(struct drm_client_dev *client)257{258 drm_fb_helper_lastclose(client->dev);259 260 return 0;261}262 263static int drm_fbdev_dma_client_hotplug(struct drm_client_dev *client)264{265 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);266 struct drm_device *dev = client->dev;267 int ret;268 269 if (dev->fb_helper)270 return drm_fb_helper_hotplug_event(dev->fb_helper);271 272 ret = drm_fb_helper_init(dev, fb_helper);273 if (ret)274 goto err_drm_err;275 276 if (!drm_drv_uses_atomic_modeset(dev))277 drm_helper_disable_unused_functions(dev);278 279 ret = drm_fb_helper_initial_config(fb_helper);280 if (ret)281 goto err_drm_fb_helper_fini;282 283 return 0;284 285err_drm_fb_helper_fini:286 drm_fb_helper_fini(fb_helper);287err_drm_err:288 drm_err(dev, "fbdev-dma: Failed to setup generic emulation (ret=%d)\n", ret);289 return ret;290}291 292static const struct drm_client_funcs drm_fbdev_dma_client_funcs = {293 .owner = THIS_MODULE,294 .unregister = drm_fbdev_dma_client_unregister,295 .restore = drm_fbdev_dma_client_restore,296 .hotplug = drm_fbdev_dma_client_hotplug,297};298 299/**300 * drm_fbdev_dma_setup() - Setup fbdev emulation for GEM DMA helpers301 * @dev: DRM device302 * @preferred_bpp: Preferred bits per pixel for the device.303 * 32 is used if this is zero.304 *305 * This function sets up fbdev emulation for GEM DMA drivers that support306 * dumb buffers with a virtual address and that can be mmap'ed.307 * drm_fbdev_dma_setup() shall be called after the DRM driver registered308 * the new DRM device with drm_dev_register().309 *310 * Restore, hotplug events and teardown are all taken care of. Drivers that do311 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.312 * Simple drivers might use drm_mode_config_helper_suspend().313 *314 * This function is safe to call even when there are no connectors present.315 * Setup will be retried on the next hotplug event.316 *317 * The fbdev is destroyed by drm_dev_unregister().318 */319void drm_fbdev_dma_setup(struct drm_device *dev, unsigned int preferred_bpp)320{321 struct drm_fb_helper *fb_helper;322 int ret;323 324 drm_WARN(dev, !dev->registered, "Device has not been registered.\n");325 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");326 327 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);328 if (!fb_helper)329 return;330 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_dma_helper_funcs);331 332 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_dma_client_funcs);333 if (ret) {334 drm_err(dev, "Failed to register client: %d\n", ret);335 goto err_drm_client_init;336 }337 338 drm_client_register(&fb_helper->client);339 340 return;341 342err_drm_client_init:343 drm_fb_helper_unprepare(fb_helper);344 kfree(fb_helper);345}346EXPORT_SYMBOL(drm_fbdev_dma_setup);347