The DRM device struct_mutex is used to protect against concurrent GEM object operations that deal with memory allocation and pinning. All those operations are local to a GEM object and don't need to be serialized across different GEM objects. Replace the struct_mutex with a local omap_obj.lock or drop it altogether where not needed.
Signed-off-by: Laurent Pinchart <[email protected]> Reviewed-by: Tomi Valkeinen <[email protected]> --- Changes since v1: - Use lockdep_assert_held() to verify locking correctness --- drivers/gpu/drm/omapdrm/omap_debugfs.c | 7 -- drivers/gpu/drm/omapdrm/omap_fbdev.c | 8 +-- drivers/gpu/drm/omapdrm/omap_gem.c | 122 +++++++++++++++++++++------------ 3 files changed, 81 insertions(+), 56 deletions(-) diff --git a/drivers/gpu/drm/omapdrm/omap_debugfs.c b/drivers/gpu/drm/omapdrm/omap_debugfs.c index b42e286616b0..95ade441caa8 100644 --- a/drivers/gpu/drm/omapdrm/omap_debugfs.c +++ b/drivers/gpu/drm/omapdrm/omap_debugfs.c @@ -30,17 +30,10 @@ static int gem_show(struct seq_file *m, void *arg) struct drm_info_node *node = (struct drm_info_node *) m->private; struct drm_device *dev = node->minor->dev; struct omap_drm_private *priv = dev->dev_private; - int ret; - - ret = mutex_lock_interruptible(&dev->struct_mutex); - if (ret) - return ret; seq_printf(m, "All Objects:\n"); omap_gem_describe_objects(&priv->obj_list, m); - mutex_unlock(&dev->struct_mutex); - return 0; } diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c index 0f66c74a54b0..d958cc813a94 100644 --- a/drivers/gpu/drm/omapdrm/omap_fbdev.c +++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c @@ -170,13 +170,11 @@ static int omap_fbdev_create(struct drm_fb_helper *helper, goto fail; } - mutex_lock(&dev->struct_mutex); - fbi = drm_fb_helper_alloc_fbi(helper); if (IS_ERR(fbi)) { dev_err(dev->dev, "failed to allocate fb info\n"); ret = PTR_ERR(fbi); - goto fail_unlock; + goto fail; } DBG("fbi=%p, dev=%p", fbi, dev); @@ -212,12 +210,8 @@ static int omap_fbdev_create(struct drm_fb_helper *helper, DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres); DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height); - mutex_unlock(&dev->struct_mutex); - return 0; -fail_unlock: - mutex_unlock(&dev->struct_mutex); fail: if (ret) { diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c index 0a9ba1f711e6..39cbc7273b29 100644 --- a/drivers/gpu/drm/omapdrm/omap_gem.c +++ b/drivers/gpu/drm/omapdrm/omap_gem.c @@ -47,6 +47,9 @@ struct omap_gem_object { /** roll applied when mapping to DMM */ u32 roll; + /** protects dma_addr_cnt, block, pages, dma_addrs and vaddr */ + struct mutex lock; + /** * dma_addr contains the buffer DMA address. It is valid for * @@ -220,7 +223,10 @@ static void omap_gem_evict(struct drm_gem_object *obj) * Page Management */ -/* Ensure backing pages are allocated. */ +/* + * Ensure backing pages are allocated. Must be called with the omap_obj.lock + * held. + */ static int omap_gem_attach_pages(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; @@ -230,6 +236,8 @@ static int omap_gem_attach_pages(struct drm_gem_object *obj) int i, ret; dma_addr_t *addrs; + lockdep_assert_held(&omap_obj->lock); + /* * If not using shmem (in which case backing pages don't need to be * allocated) or if pages are already allocated we're done. @@ -291,13 +299,15 @@ static int omap_gem_attach_pages(struct drm_gem_object *obj) return ret; } -/** release backing pages */ +/* Release backing pages. Must be called with the omap_obj.lock held. */ static void omap_gem_detach_pages(struct drm_gem_object *obj) { struct omap_gem_object *omap_obj = to_omap_bo(obj); unsigned int npages = obj->size >> PAGE_SHIFT; unsigned int i; + lockdep_assert_held(&omap_obj->lock); + for (i = 0; i < npages; i++) { if (omap_obj->dma_addrs[i]) dma_unmap_page(obj->dev->dev, omap_obj->dma_addrs[i], @@ -485,13 +495,12 @@ int omap_gem_fault(struct vm_fault *vmf) struct vm_area_struct *vma = vmf->vma; struct drm_gem_object *obj = vma->vm_private_data; struct omap_gem_object *omap_obj = to_omap_bo(obj); - struct drm_device *dev = obj->dev; int ret; /* 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(&omap_obj->lock); /* if a shmem backed object, make sure we have pages attached now */ ret = omap_gem_attach_pages(obj); @@ -511,7 +520,7 @@ int omap_gem_fault(struct vm_fault *vmf) fail: - mutex_unlock(&dev->struct_mutex); + mutex_unlock(&omap_obj->lock); switch (ret) { case 0: case -ERESTARTSYS: @@ -659,7 +668,7 @@ int omap_gem_roll(struct drm_gem_object *obj, u32 roll) omap_obj->roll = roll; - mutex_lock(&obj->dev->struct_mutex); + mutex_lock(&omap_obj->lock); /* if we aren't mapped yet, we don't need to do anything */ if (omap_obj->block) { @@ -674,7 +683,7 @@ int omap_gem_roll(struct drm_gem_object *obj, u32 roll) } fail: - mutex_unlock(&obj->dev->struct_mutex); + mutex_unlock(&omap_obj->lock); return ret; } @@ -775,7 +784,7 @@ int omap_gem_pin(struct drm_gem_object *obj, dma_addr_t *dma_addr) struct omap_gem_object *omap_obj = to_omap_bo(obj); int ret = 0; - mutex_lock(&obj->dev->struct_mutex); + mutex_lock(&omap_obj->lock); if (!omap_gem_is_contiguous(omap_obj) && priv->has_dmm) { if (omap_obj->dma_addr_cnt == 0) { @@ -831,7 +840,7 @@ int omap_gem_pin(struct drm_gem_object *obj, dma_addr_t *dma_addr) } fail: - mutex_unlock(&obj->dev->struct_mutex); + mutex_unlock(&omap_obj->lock); return ret; } @@ -849,7 +858,8 @@ void omap_gem_unpin(struct drm_gem_object *obj) struct omap_gem_object *omap_obj = to_omap_bo(obj); int ret; - mutex_lock(&obj->dev->struct_mutex); + mutex_lock(&omap_obj->lock); + if (omap_obj->dma_addr_cnt > 0) { omap_obj->dma_addr_cnt--; if (omap_obj->dma_addr_cnt == 0) { @@ -868,7 +878,7 @@ void omap_gem_unpin(struct drm_gem_object *obj) } } - mutex_unlock(&obj->dev->struct_mutex); + mutex_unlock(&omap_obj->lock); } /* Get rotated scanout address (only valid if already pinned), at the @@ -881,13 +891,16 @@ int omap_gem_rotated_dma_addr(struct drm_gem_object *obj, u32 orient, struct omap_gem_object *omap_obj = to_omap_bo(obj); int ret = -EINVAL; - mutex_lock(&obj->dev->struct_mutex); + mutex_lock(&omap_obj->lock); + if ((omap_obj->dma_addr_cnt > 0) && omap_obj->block && (omap_obj->flags & OMAP_BO_TILED)) { *dma_addr = tiler_tsptr(omap_obj->block, orient, x, y); ret = 0; } - mutex_unlock(&obj->dev->struct_mutex); + + mutex_unlock(&omap_obj->lock); + return ret; } @@ -915,18 +928,26 @@ int omap_gem_get_pages(struct drm_gem_object *obj, struct page ***pages, bool remap) { struct omap_gem_object *omap_obj = to_omap_bo(obj); - int ret; + int ret = 0; - if (!remap) { - if (!omap_obj->pages) - return -ENOMEM; - *pages = omap_obj->pages; - return 0; + mutex_lock(&omap_obj->lock); + + if (remap) { + ret = omap_gem_attach_pages(obj); + if (ret) + goto unlock; } - mutex_lock(&obj->dev->struct_mutex); - ret = omap_gem_attach_pages(obj); + + if (!omap_obj->pages) { + ret = -ENOMEM; + goto unlock; + } + *pages = omap_obj->pages; - mutex_unlock(&obj->dev->struct_mutex); + +unlock: + mutex_unlock(&omap_obj->lock); + return ret; } @@ -941,24 +962,34 @@ int omap_gem_put_pages(struct drm_gem_object *obj) } #ifdef CONFIG_DRM_FBDEV_EMULATION -/* Get kernel virtual address for CPU access.. this more or less only - * exists for omap_fbdev. This should be called with struct_mutex - * held. +/* + * Get kernel virtual address for CPU access.. this more or less only + * exists for omap_fbdev. */ void *omap_gem_vaddr(struct drm_gem_object *obj) { struct omap_gem_object *omap_obj = to_omap_bo(obj); - WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex)); - if (!omap_obj->vaddr) { - int ret; + void *vaddr; + int ret; + + mutex_lock(&omap_obj->lock); + if (!omap_obj->vaddr) { ret = omap_gem_attach_pages(obj); - if (ret) - return ERR_PTR(ret); + if (ret) { + vaddr = ERR_PTR(ret); + goto unlock; + } + omap_obj->vaddr = vmap(omap_obj->pages, obj->size >> PAGE_SHIFT, VM_MAP, pgprot_writecombine(PAGE_KERNEL)); } - return omap_obj->vaddr; + + vaddr = omap_obj->vaddr; + +unlock: + mutex_unlock(&omap_obj->lock); + return vaddr; } #endif @@ -1006,6 +1037,8 @@ void omap_gem_describe(struct drm_gem_object *obj, struct seq_file *m) off = drm_vma_node_start(&obj->vma_node); + mutex_lock(&omap_obj->lock); + seq_printf(m, "%08x: %2d (%2d) %08llx %pad (%2d) %p %4d", omap_obj->flags, obj->name, kref_read(&obj->refcount), off, &omap_obj->dma_addr, omap_obj->dma_addr_cnt, @@ -1023,6 +1056,8 @@ void omap_gem_describe(struct drm_gem_object *obj, struct seq_file *m) seq_printf(m, " %zu", obj->size); } + mutex_unlock(&omap_obj->lock); + seq_printf(m, "\n"); } @@ -1056,15 +1091,16 @@ void omap_gem_free_object(struct drm_gem_object *obj) omap_gem_evict(obj); - WARN_ON(!mutex_is_locked(&dev->struct_mutex)); - spin_lock(&priv->list_lock); list_del(&omap_obj->mm_list); spin_unlock(&priv->list_lock); - /* this means the object is still pinned.. which really should - * not happen. I think.. + /* + * No need to take the omap_obj.lock as at this point we own the sole + * reference to the object. */ + + /* The object should not be pinned. */ WARN_ON(omap_obj->dma_addr_cnt > 0); if (omap_obj->pages) { @@ -1085,6 +1121,8 @@ void omap_gem_free_object(struct drm_gem_object *obj) drm_gem_object_release(obj); + mutex_destroy(&omap_obj->lock); + kfree(omap_obj); } @@ -1140,6 +1178,7 @@ struct drm_gem_object *omap_gem_new(struct drm_device *dev, obj = &omap_obj->base; omap_obj->flags = flags; + mutex_init(&omap_obj->lock); if (flags & OMAP_BO_TILED) { /* @@ -1204,16 +1243,15 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size, if (sgt->orig_nents != 1 && !priv->has_dmm) return ERR_PTR(-EINVAL); - mutex_lock(&dev->struct_mutex); - gsize.bytes = PAGE_ALIGN(size); obj = omap_gem_new(dev, gsize, OMAP_BO_MEM_DMABUF | OMAP_BO_WC); - if (!obj) { - obj = ERR_PTR(-ENOMEM); - goto done; - } + if (!obj) + return ERR_PTR(-ENOMEM); omap_obj = to_omap_bo(obj); + + mutex_lock(&omap_obj->lock); + omap_obj->sgt = sgt; if (sgt->orig_nents == 1) { @@ -1249,7 +1287,7 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size, } done: - mutex_unlock(&dev->struct_mutex); + mutex_unlock(&omap_obj->lock); return obj; } -- Regards, Laurent Pinchart _______________________________________________ dri-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/dri-devel
