WSL2-Linux-Kernel/drivers/char/drm/drm_context.c

595 строки
15 KiB
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::context_sareas, while holding the drm_device::struct_mutex
* lock.
*/
void drm_ctxbitmap_free(drm_device_t * dev, int ctx_handle)
{
if (ctx_handle < 0)
goto failed;
if (!dev->ctx_bitmap)
goto failed;
if (ctx_handle < DRM_MAX_CTXBITMAP) {
mutex_lock(&dev->struct_mutex);
clear_bit(ctx_handle, dev->ctx_bitmap);
dev->context_sareas[ctx_handle] = NULL;
mutex_unlock(&dev->struct_mutex);
return;
}
failed:
DRM_ERROR("Attempt to free invalid context handle: %d\n", ctx_handle);
return;
}
/**
* Context bitmap allocation.
*
* \param dev DRM device.
* \return (non-negative) context handle on success or a negative number on failure.
*
* Find the first zero bit in drm_device::ctx_bitmap and (re)allocates
* drm_device::context_sareas to accommodate the new entry while holding the
* drm_device::struct_mutex lock.
*/
static int drm_ctxbitmap_next(drm_device_t * dev)
{
int bit;
if (!dev->ctx_bitmap)
return -1;
mutex_lock(&dev->struct_mutex);
bit = find_first_zero_bit(dev->ctx_bitmap, DRM_MAX_CTXBITMAP);
if (bit < DRM_MAX_CTXBITMAP) {
set_bit(bit, dev->ctx_bitmap);
DRM_DEBUG("drm_ctxbitmap_next bit : %d\n", bit);
if ((bit + 1) > dev->max_context) {
dev->max_context = (bit + 1);
if (dev->context_sareas) {
drm_map_t **ctx_sareas;
ctx_sareas = drm_realloc(dev->context_sareas,
(dev->max_context -
1) *
sizeof(*dev->
context_sareas),
dev->max_context *
sizeof(*dev->
context_sareas),
DRM_MEM_MAPS);
if (!ctx_sareas) {
clear_bit(bit, dev->ctx_bitmap);
mutex_unlock(&dev->struct_mutex);
return -1;
}
dev->context_sareas = ctx_sareas;
dev->context_sareas[bit] = NULL;
} else {
/* max_context == 1 at this point */
dev->context_sareas =
drm_alloc(dev->max_context *
sizeof(*dev->context_sareas),
DRM_MEM_MAPS);
if (!dev->context_sareas) {
clear_bit(bit, dev->ctx_bitmap);
mutex_unlock(&dev->struct_mutex);
return -1;
}
dev->context_sareas[bit] = NULL;
}
}
mutex_unlock(&dev->struct_mutex);
return bit;
}
mutex_unlock(&dev->struct_mutex);
return -1;
}
/**
* Context bitmap initialization.
*
* \param dev DRM device.
*
* Allocates and initialize drm_device::ctx_bitmap and drm_device::context_sareas, while holding
* the drm_device::struct_mutex lock.
*/
int drm_ctxbitmap_init(drm_device_t * dev)
{
int i;
int temp;
mutex_lock(&dev->struct_mutex);
dev->ctx_bitmap = (unsigned long *)drm_alloc(PAGE_SIZE,
DRM_MEM_CTXBITMAP);
if (dev->ctx_bitmap == NULL) {
mutex_unlock(&dev->struct_mutex);
return -ENOMEM;
}
memset((void *)dev->ctx_bitmap, 0, PAGE_SIZE);
dev->context_sareas = NULL;
dev->max_context = -1;
mutex_unlock(&dev->struct_mutex);
for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
temp = drm_ctxbitmap_next(dev);
DRM_DEBUG("drm_ctxbitmap_init : %d\n", temp);
}
return 0;
}
/**
* Context bitmap cleanup.
*
* \param dev DRM device.
*
* Frees drm_device::ctx_bitmap and drm_device::context_sareas, while holding
* the drm_device::struct_mutex lock.
*/
void drm_ctxbitmap_cleanup(drm_device_t * dev)
{
mutex_lock(&dev->struct_mutex);
if (dev->context_sareas)
drm_free(dev->context_sareas,
sizeof(*dev->context_sareas) *
dev->max_context, DRM_MEM_MAPS);
drm_free((void *)dev->ctx_bitmap, PAGE_SIZE, DRM_MEM_CTXBITMAP);
mutex_unlock(&dev->struct_mutex);
}
/*@}*/
/******************************************************************/
/** \name Per Context SAREA Support */
/*@{*/
/**
* Get per-context SAREA.
*
* \param inode device inode.
* \param filp file pointer.
* \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::context_sareas with the handle specified and
* returns its handle.
*/
int drm_getsareactx(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->head->dev;
drm_ctx_priv_map_t __user *argp = (void __user *)arg;
drm_ctx_priv_map_t request;
drm_map_t *map;
drm_map_list_t *_entry;
if (copy_from_user(&request, argp, sizeof(request)))
return -EFAULT;
mutex_lock(&dev->struct_mutex);
if (dev->max_context < 0
|| request.ctx_id >= (unsigned)dev->max_context) {
mutex_unlock(&dev->struct_mutex);
return -EINVAL;
}
map = dev->context_sareas[request.ctx_id];
mutex_unlock(&dev->struct_mutex);
request.handle = NULL;
list_for_each_entry(_entry, &dev->maplist->head, head) {
if (_entry->map == map) {
request.handle =
(void *)(unsigned long)_entry->user_token;
break;
}
}
if (request.handle == NULL)
return -EINVAL;
if (copy_to_user(argp, &request, sizeof(request)))
return -EFAULT;
return 0;
}
/**
* Set per-context SAREA.
*
* \param inode device inode.
* \param filp file pointer.
* \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::context_sareas with it.
*/
int drm_setsareactx(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->head->dev;
drm_ctx_priv_map_t request;
drm_map_t *map = NULL;
drm_map_list_t *r_list = NULL;
struct list_head *list;
if (copy_from_user(&request,
(drm_ctx_priv_map_t __user *) arg, sizeof(request)))
return -EFAULT;
mutex_lock(&dev->struct_mutex);
list_for_each(list, &dev->maplist->head) {
r_list = list_entry(list, drm_map_list_t, 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 (dev->max_context < 0)
goto bad;
if (request.ctx_id >= (unsigned)dev->max_context)
goto bad;
dev->context_sareas[request.ctx_id] = map;
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(drm_device_t * 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(drm_device_t * dev, int new)
{
dev->last_context = new; /* PRE/POST: This is the _only_ writer. */
dev->last_switch = jiffies;
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);
wake_up(&dev->context_wait);
return 0;
}
/**
* Reserve contexts.
*
* \param inode device inode.
* \param filp file pointer.
* \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 inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
drm_ctx_res_t res;
drm_ctx_t __user *argp = (void __user *)arg;
drm_ctx_t ctx;
int i;
if (copy_from_user(&res, argp, sizeof(res)))
return -EFAULT;
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;
if (copy_to_user(argp, &res, sizeof(res)))
return -EFAULT;
return 0;
}
/**
* Add context.
*
* \param inode device inode.
* \param filp file pointer.
* \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 inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->head->dev;
drm_ctx_list_t *ctx_entry;
drm_ctx_t __user *argp = (void __user *)arg;
drm_ctx_t ctx;
if (copy_from_user(&ctx, argp, sizeof(ctx)))
return -EFAULT;
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 (ctx.handle != DRM_KERNEL_CONTEXT) {
if (dev->driver->context_ctor)
if (!dev->driver->context_ctor(dev, ctx.handle)) {
DRM_DEBUG("Running out of ctxs or memory.\n");
return -ENOMEM;
}
}
ctx_entry = drm_alloc(sizeof(*ctx_entry), DRM_MEM_CTXLIST);
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 = priv;
mutex_lock(&dev->ctxlist_mutex);
list_add(&ctx_entry->head, &dev->ctxlist->head);
++dev->ctx_count;
mutex_unlock(&dev->ctxlist_mutex);
if (copy_to_user(argp, &ctx, sizeof(ctx)))
return -EFAULT;
return 0;
}
int drm_modctx(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
/* This does nothing */
return 0;
}
/**
* Get context.
*
* \param inode device inode.
* \param filp file pointer.
* \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 inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
drm_ctx_t __user *argp = (void __user *)arg;
drm_ctx_t ctx;
if (copy_from_user(&ctx, argp, sizeof(ctx)))
return -EFAULT;
/* This is 0, because we don't handle any context flags */
ctx.flags = 0;
if (copy_to_user(argp, &ctx, sizeof(ctx)))
return -EFAULT;
return 0;
}
/**
* Switch context.
*
* \param inode device inode.
* \param filp file pointer.
* \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 inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->head->dev;
drm_ctx_t ctx;
if (copy_from_user(&ctx, (drm_ctx_t __user *) arg, sizeof(ctx)))
return -EFAULT;
DRM_DEBUG("%d\n", ctx.handle);
return drm_context_switch(dev, dev->last_context, ctx.handle);
}
/**
* New context.
*
* \param inode device inode.
* \param filp file pointer.
* \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 inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->head->dev;
drm_ctx_t ctx;
if (copy_from_user(&ctx, (drm_ctx_t __user *) arg, sizeof(ctx)))
return -EFAULT;
DRM_DEBUG("%d\n", ctx.handle);
drm_context_switch_complete(dev, ctx.handle);
return 0;
}
/**
* Remove context.
*
* \param inode device inode.
* \param filp file pointer.
* \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 inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->head->dev;
drm_ctx_t ctx;
if (copy_from_user(&ctx, (drm_ctx_t __user *) arg, sizeof(ctx)))
return -EFAULT;
DRM_DEBUG("%d\n", ctx.handle);
if (ctx.handle == DRM_KERNEL_CONTEXT + 1) {
priv->remove_auth_on_close = 1;
}
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->head)) {
drm_ctx_list_t *pos, *n;
list_for_each_entry_safe(pos, n, &dev->ctxlist->head, head) {
if (pos->handle == ctx.handle) {
list_del(&pos->head);
drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
--dev->ctx_count;
}
}
}
mutex_unlock(&dev->ctxlist_mutex);
return 0;
}
/*@}*/