freebsd-dev/sys/dev/drm/drm_context.c
Robert Noland e8ca7a9956 realloc() behaves identically to malloc when passed a NULL object pointer
If an error does occur we would have left max_context with an incorrect
value.

MFC after:	3 days
2009-06-20 16:40:48 +00:00

313 lines
7.3 KiB
C

/*-
* 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.
*
* Authors:
* Rickard E. (Rik) Faith <faith@valinux.com>
* Gareth Hughes <gareth@valinux.com>
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/** @file drm_context.c
* Implementation of the context management ioctls.
*/
#include "dev/drm/drmP.h"
/* ================================================================
* Context bitmap support
*/
void drm_ctxbitmap_free(struct drm_device *dev, int ctx_handle)
{
if (ctx_handle < 0 || ctx_handle >= DRM_MAX_CTXBITMAP ||
dev->ctx_bitmap == NULL) {
DRM_ERROR("Attempt to free invalid context handle: %d\n",
ctx_handle);
return;
}
DRM_LOCK();
clear_bit(ctx_handle, dev->ctx_bitmap);
dev->context_sareas[ctx_handle] = NULL;
DRM_UNLOCK();
return;
}
int drm_ctxbitmap_next(struct drm_device *dev)
{
int bit;
if (dev->ctx_bitmap == NULL)
return -1;
DRM_LOCK();
bit = find_first_zero_bit(dev->ctx_bitmap, DRM_MAX_CTXBITMAP);
if (bit >= DRM_MAX_CTXBITMAP) {
DRM_UNLOCK();
return -1;
}
set_bit(bit, dev->ctx_bitmap);
DRM_DEBUG("bit : %d\n", bit);
if ((bit+1) > dev->max_context) {
drm_local_map_t **ctx_sareas;
int max_ctx = (bit+1);
ctx_sareas = realloc(dev->context_sareas,
max_ctx * sizeof(*dev->context_sareas),
DRM_MEM_SAREA, M_NOWAIT);
if (ctx_sareas == NULL) {
clear_bit(bit, dev->ctx_bitmap);
DRM_DEBUG("failed to allocate bit : %d\n", bit);
DRM_UNLOCK();
return -1;
}
dev->max_context = max_ctx;
dev->context_sareas = ctx_sareas;
dev->context_sareas[bit] = NULL;
}
DRM_UNLOCK();
return bit;
}
int drm_ctxbitmap_init(struct drm_device *dev)
{
int i;
int temp;
DRM_LOCK();
dev->ctx_bitmap = malloc(PAGE_SIZE, DRM_MEM_CTXBITMAP,
M_NOWAIT | M_ZERO);
if (dev->ctx_bitmap == NULL) {
DRM_UNLOCK();
return ENOMEM;
}
dev->context_sareas = NULL;
dev->max_context = -1;
DRM_UNLOCK();
for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
temp = drm_ctxbitmap_next(dev);
DRM_DEBUG("drm_ctxbitmap_init : %d\n", temp);
}
return 0;
}
void drm_ctxbitmap_cleanup(struct drm_device *dev)
{
DRM_LOCK();
if (dev->context_sareas != NULL)
free(dev->context_sareas, DRM_MEM_SAREA);
free(dev->ctx_bitmap, DRM_MEM_CTXBITMAP);
DRM_UNLOCK();
}
/* ================================================================
* Per Context SAREA Support
*/
int drm_getsareactx(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_ctx_priv_map *request = data;
drm_local_map_t *map;
DRM_LOCK();
if (dev->max_context < 0 ||
request->ctx_id >= (unsigned) dev->max_context) {
DRM_UNLOCK();
return EINVAL;
}
map = dev->context_sareas[request->ctx_id];
DRM_UNLOCK();
request->handle = map->handle;
return 0;
}
int drm_setsareactx(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_ctx_priv_map *request = data;
drm_local_map_t *map = NULL;
DRM_LOCK();
TAILQ_FOREACH(map, &dev->maplist, link) {
if (map->handle == request->handle) {
if (dev->max_context < 0)
goto bad;
if (request->ctx_id >= (unsigned) dev->max_context)
goto bad;
dev->context_sareas[request->ctx_id] = map;
DRM_UNLOCK();
return 0;
}
}
bad:
DRM_UNLOCK();
return EINVAL;
}
/* ================================================================
* The actual DRM context handling routines
*/
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;
}
int drm_context_switch_complete(struct drm_device *dev, int new)
{
dev->last_context = new; /* PRE/POST: This is the _only_ writer. */
if (!_DRM_LOCK_IS_HELD(dev->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);
return 0;
}
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) {
bzero(&ctx, sizeof(ctx));
for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
ctx.handle = i;
if (DRM_COPY_TO_USER(&res->contexts[i],
&ctx, sizeof(ctx)))
return EFAULT;
}
}
res->count = DRM_RESERVED_CONTEXTS;
return 0;
}
int drm_addctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
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;
}
if (dev->driver->context_ctor && ctx->handle != DRM_KERNEL_CONTEXT) {
DRM_LOCK();
dev->driver->context_ctor(dev, ctx->handle);
DRM_UNLOCK();
}
return 0;
}
int drm_modctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
/* This does nothing */
return 0;
}
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;
}
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);
}
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, ctx->handle);
return 0;
}
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) {
DRM_LOCK();
dev->driver->context_dtor(dev, ctx->handle);
DRM_UNLOCK();
}
drm_ctxbitmap_free(dev, ctx->handle);
}
return 0;
}