- 根目录:
- drivers
- gpu
- drm
- drm_context.c
/**
* \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;
}
/*@}*/