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drm/i810: remove the BKL

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SMP i810 systems were practically nonexistent and the configuration
was not officially supported by Intel at the time when Pentium-III
was common.

With this change, it is still possible to build a distribution kernel
that has support for SMP and includes the i810 driver without the BKL.
As a precaution, check for the theoretical SMP case at run time and
refuse to load the driver.

We also need to disable CONFIG_PREEMPT builds for this driver.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Arnd Bergmann 2011-01-25 23:17:15 +01:00 committed by Dave Airlie
parent 7f50684717
commit 1f692a14cb
3 changed files with 8 additions and 20 deletions
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4
drivers/gpu/drm/Kconfig
View File

@ -73,8 +73,8 @@ source "drivers/gpu/drm/radeon/Kconfig"
config DRM_I810 config DRM_I810
tristate "Intel I810" tristate "Intel I810"
# BKL usage in order to avoid AB-BA deadlocks, may become BROKEN_ON_SMP # !PREEMPT because of missing ioctl locking
depends on DRM && AGP && AGP_INTEL && BKL depends on DRM && AGP && AGP_INTEL && (!PREEMPT || BROKEN)
help help
Choose this option if you have an Intel I810 graphics card. If M is Choose this option if you have an Intel I810 graphics card. If M is
selected, the module will be called i810. AGP support is required selected, the module will be called i810. AGP support is required

18
drivers/gpu/drm/i810/i810_dma.c
View File

@ -37,7 +37,6 @@
#include <linux/interrupt.h> /* For task queue support */ #include <linux/interrupt.h> /* For task queue support */
#include <linux/delay.h> #include <linux/delay.h>
#include <linux/slab.h> #include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/pagemap.h> #include <linux/pagemap.h>
#define I810_BUF_FREE 2 #define I810_BUF_FREE 2
@ -94,7 +93,6 @@ static int i810_mmap_buffers(struct file *filp, struct vm_area_struct *vma)
struct drm_buf *buf; struct drm_buf *buf;
drm_i810_buf_priv_t *buf_priv; drm_i810_buf_priv_t *buf_priv;
lock_kernel();
dev = priv->minor->dev; dev = priv->minor->dev;
dev_priv = dev->dev_private; dev_priv = dev->dev_private;
buf = dev_priv->mmap_buffer; buf = dev_priv->mmap_buffer;
@ -104,7 +102,6 @@ static int i810_mmap_buffers(struct file *filp, struct vm_area_struct *vma)
vma->vm_file = filp; vma->vm_file = filp;
buf_priv->currently_mapped = I810_BUF_MAPPED; buf_priv->currently_mapped = I810_BUF_MAPPED;
unlock_kernel();
if (io_remap_pfn_range(vma, vma->vm_start, if (io_remap_pfn_range(vma, vma->vm_start,
vma->vm_pgoff, vma->vm_pgoff,
@ -116,7 +113,7 @@ static int i810_mmap_buffers(struct file *filp, struct vm_area_struct *vma)
static const struct file_operations i810_buffer_fops = { static const struct file_operations i810_buffer_fops = {
.open = drm_open, .open = drm_open,
.release = drm_release, .release = drm_release,
.unlocked_ioctl = i810_ioctl, .unlocked_ioctl = drm_ioctl,
.mmap = i810_mmap_buffers, .mmap = i810_mmap_buffers,
.fasync = drm_fasync, .fasync = drm_fasync,
.llseek = noop_llseek, .llseek = noop_llseek,
@ -1242,19 +1239,6 @@ int i810_driver_dma_quiescent(struct drm_device *dev)
return 0; return 0;
} }
/*
* call the drm_ioctl under the big kernel lock because
* to lock against the i810_mmap_buffers function.
*/
long i810_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int ret;
lock_kernel();
ret = drm_ioctl(file, cmd, arg);
unlock_kernel();
return ret;
}
struct drm_ioctl_desc i810_ioctls[] = { struct drm_ioctl_desc i810_ioctls[] = {
DRM_IOCTL_DEF_DRV(I810_INIT, i810_dma_init, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY|DRM_UNLOCKED), DRM_IOCTL_DEF_DRV(I810_INIT, i810_dma_init, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY|DRM_UNLOCKED),
DRM_IOCTL_DEF_DRV(I810_VERTEX, i810_dma_vertex, DRM_AUTH|DRM_UNLOCKED), DRM_IOCTL_DEF_DRV(I810_VERTEX, i810_dma_vertex, DRM_AUTH|DRM_UNLOCKED),

6
drivers/gpu/drm/i810/i810_drv.c
View File

@ -57,7 +57,7 @@ static struct drm_driver driver = {
.owner = THIS_MODULE, .owner = THIS_MODULE,
.open = drm_open, .open = drm_open,
.release = drm_release, .release = drm_release,
.unlocked_ioctl = i810_ioctl, .unlocked_ioctl = drm_ioctl,
.mmap = drm_mmap, .mmap = drm_mmap,
.poll = drm_poll, .poll = drm_poll,
.fasync = drm_fasync, .fasync = drm_fasync,
@ -79,6 +79,10 @@ static struct drm_driver driver = {
static int __init i810_init(void) static int __init i810_init(void)
{ {
if (num_possible_cpus() > 1) {
pr_err("drm/i810 does not support SMP\n");
return -EINVAL;
}
driver.num_ioctls = i810_max_ioctl; driver.num_ioctls = i810_max_ioctl;
return drm_init(&driver); return drm_init(&driver);
} }