/** * \file drm_context.c * IOCTLs for generic contexts * * \author Rickard E. (Rik) Faith <faith@valinux.com> * \author Gareth Hughes <gareth@valinux.com> */ /* * Created: Fri Nov 24 18:31:37 2000 by gareth@valinux.com * * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas. * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ /* * ChangeLog: * 2001-11-16 Torsten Duwe <duwe@caldera.de> * added context constructor/destructor hooks, * needed by SiS driver's memory management. */ #include "drmP.h" /******************************************************************/ /** \name Context bitmap support */ /*@{*/ /** * Free a handle from the context bitmap. * * \param dev DRM device. * \param ctx_handle context handle. * * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry * in drm_device::ctx_idr, while holding the drm_device::struct_mutex * lock. */ void drm_ctxbitmap_free(struct drm_device * dev, int ctx_handle) { mutex_lock(&dev->struct_mutex); idr_remove(&dev->ctx_idr, ctx_handle); mutex_unlock(&dev->struct_mutex); } /** * Context bitmap allocation. * * \param dev DRM device. * \return (non-negative) context handle on success or a negative number on failure. * * Allocate a new idr from drm_device::ctx_idr while holding the * drm_device::struct_mutex lock. */ static int drm_ctxbitmap_next(struct drm_device * dev) { int new_id; int ret; again: if (idr_pre_get(&dev->ctx_idr, GFP_KERNEL) == 0) { DRM_ERROR("Out of memory expanding drawable idr\n"); return -ENOMEM; } mutex_lock(&dev->struct_mutex); ret = idr_get_new_above(&dev->ctx_idr, NULL, DRM_RESERVED_CONTEXTS, &new_id); if (ret == -EAGAIN) { mutex_unlock(&dev->struct_mutex); goto again; } mutex_unlock(&dev->struct_mutex); return new_id; } /** * Context bitmap initialization. * * \param dev DRM device. * * Initialise the drm_device::ctx_idr */ int drm_ctxbitmap_init(struct drm_device * dev) { idr_init(&dev->ctx_idr); return 0; } /** * Context bitmap cleanup. * * \param dev DRM device. * * Free all idr members using drm_ctx_sarea_free helper function * while holding the drm_device::struct_mutex lock. */ void drm_ctxbitmap_cleanup(struct drm_device * dev) { mutex_lock(&dev->struct_mutex); idr_remove_all(&dev->ctx_idr); mutex_unlock(&dev->struct_mutex); } /*@}*/ /******************************************************************/ /** \name Per Context SAREA Support */ /*@{*/ /** * Get per-context SAREA. * * \param inode device inode. * \param file_priv DRM file private. * \param cmd command. * \param arg user argument pointing to a drm_ctx_priv_map structure. * \return zero on success or a negative number on failure. * * Gets the map from drm_device::ctx_idr with the handle specified and * returns its handle. */ int drm_getsareactx(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_ctx_priv_map *request = data; struct drm_local_map *map; struct drm_map_list *_entry; mutex_lock(&dev->struct_mutex); map = idr_find(&dev->ctx_idr, request->ctx_id); if (!map) { mutex_unlock(&dev->struct_mutex); return -EINVAL; } mutex_unlock(&dev->struct_mutex); request->handle = NULL; list_for_each_entry(_entry, &dev->maplist, head) { if (_entry->map == map) { request->handle = (void *)(unsigned long)_entry->user_token; break; } } if (request->handle == NULL) return -EINVAL; return 0; } /** * Set per-context SAREA. * * \param inode device inode. * \param file_priv DRM file private. * \param cmd command. * \param arg user argument pointing to a drm_ctx_priv_map structure. * \return zero on success or a negative number on failure. * * Searches the mapping specified in \p arg and update the entry in * drm_device::ctx_idr with it. */ int drm_setsareactx(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_ctx_priv_map *request = data; struct drm_local_map *map = NULL; struct drm_map_list *r_list = NULL; mutex_lock(&dev->struct_mutex); list_for_each_entry(r_list, &dev->maplist, head) { if (r_list->map && r_list->user_token == (unsigned long) request->handle) goto found; } bad: mutex_unlock(&dev->struct_mutex); return -EINVAL; found: map = r_list->map; if (!map) goto bad; if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id))) goto bad; mutex_unlock(&dev->struct_mutex); return 0; } /*@}*/ /******************************************************************/ /** \name The actual DRM context handling routines */ /*@{*/ /** * Switch context. * * \param dev DRM device. * \param old old context handle. * \param new new context handle. * \return zero on success or a negative number on failure. * * Attempt to set drm_device::context_flag. */ static int drm_context_switch(struct drm_device * dev, int old, int new) { if (test_and_set_bit(0, &dev->context_flag)) { DRM_ERROR("Reentering -- FIXME\n"); return -EBUSY; } DRM_DEBUG("Context switch from %d to %d\n", old, new); if (new == dev->last_context) { clear_bit(0, &dev->context_flag); return 0; } return 0; } /** * Complete context switch. * * \param dev DRM device. * \param new new context handle. * \return zero on success or a negative number on failure. * * Updates drm_device::last_context and drm_device::last_switch. Verifies the * hardware lock is held, clears the drm_device::context_flag and wakes up * drm_device::context_wait. */ static int drm_context_switch_complete(struct drm_device *dev, struct drm_file *file_priv, int new) { dev->last_context = new; /* PRE/POST: This is the _only_ writer. */ dev->last_switch = jiffies; if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) { DRM_ERROR("Lock isn't held after context switch\n"); } /* If a context switch is ever initiated when the kernel holds the lock, release that lock here. */ clear_bit(0, &dev->context_flag); wake_up(&dev->context_wait); return 0; } /** * Reserve contexts. * * \param inode device inode. * \param file_priv DRM file private. * \param cmd command. * \param arg user argument pointing to a drm_ctx_res structure. * \return zero on success or a negative number on failure. */ int drm_resctx(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_ctx_res *res = data; struct drm_ctx ctx; int i; if (res->count >= DRM_RESERVED_CONTEXTS) { memset(&ctx, 0, sizeof(ctx)); for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) { ctx.handle = i; if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx))) return -EFAULT; } } res->count = DRM_RESERVED_CONTEXTS; return 0; } /** * Add context. * * \param inode device inode. * \param file_priv DRM file private. * \param cmd command. * \param arg user argument pointing to a drm_ctx structure. * \return zero on success or a negative number on failure. * * Get a new handle for the context and copy to userspace. */ int drm_addctx(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_ctx_list *ctx_entry; struct drm_ctx *ctx = data; ctx->handle = drm_ctxbitmap_next(dev); if (ctx->handle == DRM_KERNEL_CONTEXT) { /* Skip kernel's context and get a new one. */ ctx->handle = drm_ctxbitmap_next(dev); } DRM_DEBUG("%d\n", ctx->handle); if (ctx->handle == -1) { DRM_DEBUG("Not enough free contexts.\n"); /* Should this return -EBUSY instead? */ return -ENOMEM; } ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL); if (!ctx_entry) { DRM_DEBUG("out of memory\n"); return -ENOMEM; } INIT_LIST_HEAD(&ctx_entry->head); ctx_entry->handle = ctx->handle; ctx_entry->tag = file_priv; mutex_lock(&dev->ctxlist_mutex); list_add(&ctx_entry->head, &dev->ctxlist); ++dev->ctx_count; mutex_unlock(&dev->ctxlist_mutex); return 0; } int drm_modctx(struct drm_device *dev, void *data, struct drm_file *file_priv) { /* This does nothing */ return 0; } /** * Get context. * * \param inode device inode. * \param file_priv DRM file private. * \param cmd command. * \param arg user argument pointing to a drm_ctx structure. * \return zero on success or a negative number on failure. */ int drm_getctx(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_ctx *ctx = data; /* This is 0, because we don't handle any context flags */ ctx->flags = 0; return 0; } /** * Switch context. * * \param inode device inode. * \param file_priv DRM file private. * \param cmd command. * \param arg user argument pointing to a drm_ctx structure. * \return zero on success or a negative number on failure. * * Calls context_switch(). */ int drm_switchctx(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_ctx *ctx = data; DRM_DEBUG("%d\n", ctx->handle); return drm_context_switch(dev, dev->last_context, ctx->handle); } /** * New context. * * \param inode device inode. * \param file_priv DRM file private. * \param cmd command. * \param arg user argument pointing to a drm_ctx structure. * \return zero on success or a negative number on failure. * * Calls context_switch_complete(). */ int drm_newctx(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_ctx *ctx = data; DRM_DEBUG("%d\n", ctx->handle); drm_context_switch_complete(dev, file_priv, ctx->handle); return 0; } /** * Remove context. * * \param inode device inode. * \param file_priv DRM file private. * \param cmd command. * \param arg user argument pointing to a drm_ctx structure. * \return zero on success or a negative number on failure. * * If not the special kernel context, calls ctxbitmap_free() to free the specified context. */ int drm_rmctx(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_ctx *ctx = data; DRM_DEBUG("%d\n", ctx->handle); if (ctx->handle != DRM_KERNEL_CONTEXT) { if (dev->driver->context_dtor) dev->driver->context_dtor(dev, ctx->handle); drm_ctxbitmap_free(dev, ctx->handle); } mutex_lock(&dev->ctxlist_mutex); if (!list_empty(&dev->ctxlist)) { struct drm_ctx_list *pos, *n; list_for_each_entry_safe(pos, n, &dev->ctxlist, head) { if (pos->handle == ctx->handle) { list_del(&pos->head); kfree(pos); --dev->ctx_count; } } } mutex_unlock(&dev->ctxlist_mutex); return 0; } /*@}*/