drm/gma500: Add driver private mutex for the fault handler

There's currently two places where the gma500 fault handler relies
upon dev->struct_mutex:
- To protect r->mappping
- To make sure vm_insert_pfn isn't called concurrently (in which case
  the 2nd thread would get an error code).

Everything else (specifically psb_gtt_pin) is already protected by
some other locks. Hence just create a new driver-private mmap_mutex
just for this function.

With this gma500 is complete dev->struct_mutex free!

Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Acked-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448271183-20523-21-git-send-email-daniel.vetter@ffwll.ch
This commit is contained in:
Daniel Vetter 2015-11-23 10:32:53 +01:00
parent 0e3089fa50
commit 737292a3c0
3 changed files with 5 additions and 2 deletions

View File

@ -182,7 +182,7 @@ int psb_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
/* Make sure we don't parallel update on a fault, nor move or remove
something from beneath our feet */
mutex_lock(&dev->struct_mutex);
mutex_lock(&dev_priv->mmap_mutex);
/* For now the mmap pins the object and it stays pinned. As things
stand that will do us no harm */
@ -208,7 +208,7 @@ int psb_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
fail:
mutex_unlock(&dev->struct_mutex);
mutex_unlock(&dev_priv->mmap_mutex);
switch (ret) {
case 0:
case -ERESTARTSYS:

View File

@ -425,6 +425,7 @@ int psb_gtt_init(struct drm_device *dev, int resume)
if (!resume) {
mutex_init(&dev_priv->gtt_mutex);
mutex_init(&dev_priv->mmap_mutex);
psb_gtt_alloc(dev);
}

View File

@ -465,6 +465,8 @@ struct drm_psb_private {
struct mutex gtt_mutex;
struct resource *gtt_mem; /* Our PCI resource */
struct mutex mmap_mutex;
struct psb_mmu_driver *mmu;
struct psb_mmu_pd *pf_pd;