drm/msm: Separate locking of buffer resources from struct_mutex
Buffer object specific resources like pages, domains, sg list
need not be protected with struct_mutex. They can be protected
with a buffer object level lock. This simplifies locking and
makes it easier to avoid potential recursive locking scenarios
for SVM involving mmap_sem and struct_mutex. This also removes
unnecessary serialization when creating buffer objects, and also
between buffer object creation and GPU command submission.
Signed-off-by: Sushmita Susheelendra <ssusheel@codeaurora.org>
[robclark: squash in handling new locking for shrinker]
Signed-off-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 9951c78..65f3554 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -26,6 +26,9 @@
#include "msm_gpu.h"
#include "msm_mmu.h"
+static void msm_gem_vunmap_locked(struct drm_gem_object *obj);
+
+
static dma_addr_t physaddr(struct drm_gem_object *obj)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
@@ -41,8 +44,7 @@ static bool use_pages(struct drm_gem_object *obj)
}
/* allocate pages from VRAM carveout, used when no IOMMU: */
-static struct page **get_pages_vram(struct drm_gem_object *obj,
- int npages)
+static struct page **get_pages_vram(struct drm_gem_object *obj, int npages)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
struct msm_drm_private *priv = obj->dev->dev_private;
@@ -54,7 +56,9 @@ static struct page **get_pages_vram(struct drm_gem_object *obj,
if (!p)
return ERR_PTR(-ENOMEM);
+ spin_lock(&priv->vram.lock);
ret = drm_mm_insert_node(&priv->vram.mm, msm_obj->vram_node, npages);
+ spin_unlock(&priv->vram.lock);
if (ret) {
kvfree(p);
return ERR_PTR(ret);
@@ -69,7 +73,6 @@ static struct page **get_pages_vram(struct drm_gem_object *obj,
return p;
}
-/* called with dev->struct_mutex held */
static struct page **get_pages(struct drm_gem_object *obj)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
@@ -109,6 +112,18 @@ static struct page **get_pages(struct drm_gem_object *obj)
return msm_obj->pages;
}
+static void put_pages_vram(struct drm_gem_object *obj)
+{
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
+ struct msm_drm_private *priv = obj->dev->dev_private;
+
+ spin_lock(&priv->vram.lock);
+ drm_mm_remove_node(msm_obj->vram_node);
+ spin_unlock(&priv->vram.lock);
+
+ kvfree(msm_obj->pages);
+}
+
static void put_pages(struct drm_gem_object *obj)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
@@ -125,10 +140,8 @@ static void put_pages(struct drm_gem_object *obj)
if (use_pages(obj))
drm_gem_put_pages(obj, msm_obj->pages, true, false);
- else {
- drm_mm_remove_node(msm_obj->vram_node);
- kvfree(msm_obj->pages);
- }
+ else
+ put_pages_vram(obj);
msm_obj->pages = NULL;
}
@@ -136,11 +149,18 @@ static void put_pages(struct drm_gem_object *obj)
struct page **msm_gem_get_pages(struct drm_gem_object *obj)
{
- struct drm_device *dev = obj->dev;
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
struct page **p;
- mutex_lock(&dev->struct_mutex);
+
+ mutex_lock(&msm_obj->lock);
+
+ if (WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED)) {
+ mutex_unlock(&msm_obj->lock);
+ return ERR_PTR(-EBUSY);
+ }
+
p = get_pages(obj);
- mutex_unlock(&dev->struct_mutex);
+ mutex_unlock(&msm_obj->lock);
return p;
}
@@ -195,28 +215,25 @@ int msm_gem_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct drm_gem_object *obj = vma->vm_private_data;
- struct drm_device *dev = obj->dev;
- struct msm_drm_private *priv = dev->dev_private;
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
struct page **pages;
unsigned long pfn;
pgoff_t pgoff;
int ret;
- /* This should only happen if userspace tries to pass a mmap'd
- * but unfaulted gem bo vaddr into submit ioctl, triggering
- * a page fault while struct_mutex is already held. This is
- * not a valid use-case so just bail.
+ /*
+ * vm_ops.open/drm_gem_mmap_obj and close get and put
+ * a reference on obj. So, we dont need to hold one here.
*/
- if (priv->struct_mutex_task == current)
- return VM_FAULT_SIGBUS;
-
- /* Make sure we don't parallel update on a fault, nor move or remove
- * something from beneath our feet
- */
- ret = mutex_lock_interruptible(&dev->struct_mutex);
+ ret = mutex_lock_interruptible(&msm_obj->lock);
if (ret)
goto out;
+ if (WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED)) {
+ mutex_unlock(&msm_obj->lock);
+ return VM_FAULT_SIGBUS;
+ }
+
/* make sure we have pages attached now */
pages = get_pages(obj);
if (IS_ERR(pages)) {
@@ -235,7 +252,7 @@ int msm_gem_fault(struct vm_fault *vmf)
ret = vm_insert_mixed(vma, vmf->address, __pfn_to_pfn_t(pfn, PFN_DEV));
out_unlock:
- mutex_unlock(&dev->struct_mutex);
+ mutex_unlock(&msm_obj->lock);
out:
switch (ret) {
case -EAGAIN:
@@ -259,9 +276,10 @@ int msm_gem_fault(struct vm_fault *vmf)
static uint64_t mmap_offset(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
int ret;
- WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+ WARN_ON(!mutex_is_locked(&msm_obj->lock));
/* Make it mmapable */
ret = drm_gem_create_mmap_offset(obj);
@@ -277,9 +295,11 @@ static uint64_t mmap_offset(struct drm_gem_object *obj)
uint64_t msm_gem_mmap_offset(struct drm_gem_object *obj)
{
uint64_t offset;
- mutex_lock(&obj->dev->struct_mutex);
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
+
+ mutex_lock(&msm_obj->lock);
offset = mmap_offset(obj);
- mutex_unlock(&obj->dev->struct_mutex);
+ mutex_unlock(&msm_obj->lock);
return offset;
}
@@ -289,6 +309,8 @@ static struct msm_gem_vma *add_vma(struct drm_gem_object *obj,
struct msm_gem_object *msm_obj = to_msm_bo(obj);
struct msm_gem_vma *vma;
+ WARN_ON(!mutex_is_locked(&msm_obj->lock));
+
vma = kzalloc(sizeof(*vma), GFP_KERNEL);
if (!vma)
return ERR_PTR(-ENOMEM);
@@ -306,7 +328,7 @@ static struct msm_gem_vma *lookup_vma(struct drm_gem_object *obj,
struct msm_gem_object *msm_obj = to_msm_bo(obj);
struct msm_gem_vma *vma;
- WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+ WARN_ON(!mutex_is_locked(&msm_obj->lock));
list_for_each_entry(vma, &msm_obj->vmas, list) {
if (vma->aspace == aspace)
@@ -325,13 +347,14 @@ static void del_vma(struct msm_gem_vma *vma)
kfree(vma);
}
+/* Called with msm_obj->lock locked */
static void
put_iova(struct drm_gem_object *obj)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
struct msm_gem_vma *vma, *tmp;
- WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+ WARN_ON(!mutex_is_locked(&msm_obj->lock));
list_for_each_entry_safe(vma, tmp, &msm_obj->vmas, list) {
msm_gem_unmap_vma(vma->aspace, vma, msm_obj->sgt);
@@ -339,21 +362,20 @@ put_iova(struct drm_gem_object *obj)
}
}
-/* should be called under struct_mutex.. although it can be called
- * from atomic context without struct_mutex to acquire an extra
- * iova ref if you know one is already held.
- *
- * That means when I do eventually need to add support for unpinning
- * the refcnt counter needs to be atomic_t.
- */
-int msm_gem_get_iova_locked(struct drm_gem_object *obj,
+/* get iova, taking a reference. Should have a matching put */
+int msm_gem_get_iova(struct drm_gem_object *obj,
struct msm_gem_address_space *aspace, uint64_t *iova)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
struct msm_gem_vma *vma;
int ret = 0;
- WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+ mutex_lock(&msm_obj->lock);
+
+ if (WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED)) {
+ mutex_unlock(&msm_obj->lock);
+ return -EBUSY;
+ }
vma = lookup_vma(obj, aspace);
@@ -377,24 +399,14 @@ int msm_gem_get_iova_locked(struct drm_gem_object *obj,
}
*iova = vma->iova;
+
+ mutex_unlock(&msm_obj->lock);
return 0;
fail:
del_vma(vma);
- return ret;
-}
-
-/* get iova, taking a reference. Should have a matching put */
-int msm_gem_get_iova(struct drm_gem_object *obj,
- struct msm_gem_address_space *aspace, uint64_t *iova)
-{
- int ret;
-
- mutex_lock(&obj->dev->struct_mutex);
- ret = msm_gem_get_iova_locked(obj, aspace, iova);
- mutex_unlock(&obj->dev->struct_mutex);
-
+ mutex_unlock(&msm_obj->lock);
return ret;
}
@@ -404,11 +416,12 @@ int msm_gem_get_iova(struct drm_gem_object *obj,
uint64_t msm_gem_iova(struct drm_gem_object *obj,
struct msm_gem_address_space *aspace)
{
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
struct msm_gem_vma *vma;
- mutex_lock(&obj->dev->struct_mutex);
+ mutex_lock(&msm_obj->lock);
vma = lookup_vma(obj, aspace);
- mutex_unlock(&obj->dev->struct_mutex);
+ mutex_unlock(&msm_obj->lock);
WARN_ON(!vma);
return vma ? vma->iova : 0;
@@ -455,45 +468,57 @@ int msm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
return ret;
}
-void *msm_gem_get_vaddr_locked(struct drm_gem_object *obj)
-{
- struct msm_gem_object *msm_obj = to_msm_bo(obj);
- WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
- if (!msm_obj->vaddr) {
- struct page **pages = get_pages(obj);
- if (IS_ERR(pages))
- return ERR_CAST(pages);
- msm_obj->vaddr = vmap(pages, obj->size >> PAGE_SHIFT,
- VM_MAP, pgprot_writecombine(PAGE_KERNEL));
- if (msm_obj->vaddr == NULL)
- return ERR_PTR(-ENOMEM);
- }
- msm_obj->vmap_count++;
- return msm_obj->vaddr;
-}
-
void *msm_gem_get_vaddr(struct drm_gem_object *obj)
{
- void *ret;
- mutex_lock(&obj->dev->struct_mutex);
- ret = msm_gem_get_vaddr_locked(obj);
- mutex_unlock(&obj->dev->struct_mutex);
- return ret;
-}
-
-void msm_gem_put_vaddr_locked(struct drm_gem_object *obj)
-{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
- WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
- WARN_ON(msm_obj->vmap_count < 1);
+ int ret = 0;
+
+ mutex_lock(&msm_obj->lock);
+
+ if (WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED)) {
+ mutex_unlock(&msm_obj->lock);
+ return ERR_PTR(-EBUSY);
+ }
+
+ /* increment vmap_count *before* vmap() call, so shrinker can
+ * check vmap_count (is_vunmapable()) outside of msm_obj->lock.
+ * This guarantees that we won't try to msm_gem_vunmap() this
+ * same object from within the vmap() call (while we already
+ * hold msm_obj->lock)
+ */
+ msm_obj->vmap_count++;
+
+ if (!msm_obj->vaddr) {
+ struct page **pages = get_pages(obj);
+ if (IS_ERR(pages)) {
+ ret = PTR_ERR(pages);
+ goto fail;
+ }
+ msm_obj->vaddr = vmap(pages, obj->size >> PAGE_SHIFT,
+ VM_MAP, pgprot_writecombine(PAGE_KERNEL));
+ if (msm_obj->vaddr == NULL) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ }
+
+ mutex_unlock(&msm_obj->lock);
+ return msm_obj->vaddr;
+
+fail:
msm_obj->vmap_count--;
+ mutex_unlock(&msm_obj->lock);
+ return ERR_PTR(ret);
}
void msm_gem_put_vaddr(struct drm_gem_object *obj)
{
- mutex_lock(&obj->dev->struct_mutex);
- msm_gem_put_vaddr_locked(obj);
- mutex_unlock(&obj->dev->struct_mutex);
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
+
+ mutex_lock(&msm_obj->lock);
+ WARN_ON(msm_obj->vmap_count < 1);
+ msm_obj->vmap_count--;
+ mutex_unlock(&msm_obj->lock);
}
/* Update madvise status, returns true if not purged, else
@@ -503,15 +528,21 @@ int msm_gem_madvise(struct drm_gem_object *obj, unsigned madv)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
+ mutex_lock(&msm_obj->lock);
+
WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
if (msm_obj->madv != __MSM_MADV_PURGED)
msm_obj->madv = madv;
- return (msm_obj->madv != __MSM_MADV_PURGED);
+ madv = msm_obj->madv;
+
+ mutex_unlock(&msm_obj->lock);
+
+ return (madv != __MSM_MADV_PURGED);
}
-void msm_gem_purge(struct drm_gem_object *obj)
+void msm_gem_purge(struct drm_gem_object *obj, enum msm_gem_lock subclass)
{
struct drm_device *dev = obj->dev;
struct msm_gem_object *msm_obj = to_msm_bo(obj);
@@ -520,9 +551,11 @@ void msm_gem_purge(struct drm_gem_object *obj)
WARN_ON(!is_purgeable(msm_obj));
WARN_ON(obj->import_attach);
+ mutex_lock_nested(&msm_obj->lock, subclass);
+
put_iova(obj);
- msm_gem_vunmap(obj);
+ msm_gem_vunmap_locked(obj);
put_pages(obj);
@@ -540,12 +573,16 @@ void msm_gem_purge(struct drm_gem_object *obj)
invalidate_mapping_pages(file_inode(obj->filp)->i_mapping,
0, (loff_t)-1);
+
+ mutex_unlock(&msm_obj->lock);
}
-void msm_gem_vunmap(struct drm_gem_object *obj)
+static void msm_gem_vunmap_locked(struct drm_gem_object *obj)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
+ WARN_ON(!mutex_is_locked(&msm_obj->lock));
+
if (!msm_obj->vaddr || WARN_ON(!is_vunmapable(msm_obj)))
return;
@@ -553,6 +590,15 @@ void msm_gem_vunmap(struct drm_gem_object *obj)
msm_obj->vaddr = NULL;
}
+void msm_gem_vunmap(struct drm_gem_object *obj, enum msm_gem_lock subclass)
+{
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
+
+ mutex_lock_nested(&msm_obj->lock, subclass);
+ msm_gem_vunmap_locked(obj);
+ mutex_unlock(&msm_obj->lock);
+}
+
/* must be called before _move_to_active().. */
int msm_gem_sync_object(struct drm_gem_object *obj,
struct msm_fence_context *fctx, bool exclusive)
@@ -674,7 +720,7 @@ void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
uint64_t off = drm_vma_node_start(&obj->vma_node);
const char *madv;
- WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+ mutex_lock(&msm_obj->lock);
switch (msm_obj->madv) {
case __MSM_MADV_PURGED:
@@ -715,6 +761,8 @@ void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
if (fence)
describe_fence(fence, "Exclusive", m);
rcu_read_unlock();
+
+ mutex_unlock(&msm_obj->lock);
}
void msm_gem_describe_objects(struct list_head *list, struct seq_file *m)
@@ -747,6 +795,8 @@ void msm_gem_free_object(struct drm_gem_object *obj)
list_del(&msm_obj->mm_list);
+ mutex_lock(&msm_obj->lock);
+
put_iova(obj);
if (obj->import_attach) {
@@ -761,7 +811,7 @@ void msm_gem_free_object(struct drm_gem_object *obj)
drm_prime_gem_destroy(obj, msm_obj->sgt);
} else {
- msm_gem_vunmap(obj);
+ msm_gem_vunmap_locked(obj);
put_pages(obj);
}
@@ -770,6 +820,7 @@ void msm_gem_free_object(struct drm_gem_object *obj)
drm_gem_object_release(obj);
+ mutex_unlock(&msm_obj->lock);
kfree(msm_obj);
}
@@ -780,14 +831,8 @@ int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file,
struct drm_gem_object *obj;
int ret;
- ret = mutex_lock_interruptible(&dev->struct_mutex);
- if (ret)
- return ret;
-
obj = msm_gem_new(dev, size, flags);
- mutex_unlock(&dev->struct_mutex);
-
if (IS_ERR(obj))
return PTR_ERR(obj);
@@ -802,13 +847,12 @@ int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file,
static int msm_gem_new_impl(struct drm_device *dev,
uint32_t size, uint32_t flags,
struct reservation_object *resv,
- struct drm_gem_object **obj)
+ struct drm_gem_object **obj,
+ bool struct_mutex_locked)
{
struct msm_drm_private *priv = dev->dev_private;
struct msm_gem_object *msm_obj;
- WARN_ON(!mutex_is_locked(&dev->struct_mutex));
-
switch (flags & MSM_BO_CACHE_MASK) {
case MSM_BO_UNCACHED:
case MSM_BO_CACHED:
@@ -824,6 +868,8 @@ static int msm_gem_new_impl(struct drm_device *dev,
if (!msm_obj)
return -ENOMEM;
+ mutex_init(&msm_obj->lock);
+
msm_obj->flags = flags;
msm_obj->madv = MSM_MADV_WILLNEED;
@@ -837,23 +883,28 @@ static int msm_gem_new_impl(struct drm_device *dev,
INIT_LIST_HEAD(&msm_obj->submit_entry);
INIT_LIST_HEAD(&msm_obj->vmas);
- list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+ if (struct_mutex_locked) {
+ WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+ list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+ } else {
+ mutex_lock(&dev->struct_mutex);
+ list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+ mutex_unlock(&dev->struct_mutex);
+ }
*obj = &msm_obj->base;
return 0;
}
-struct drm_gem_object *msm_gem_new(struct drm_device *dev,
- uint32_t size, uint32_t flags)
+static struct drm_gem_object *_msm_gem_new(struct drm_device *dev,
+ uint32_t size, uint32_t flags, bool struct_mutex_locked)
{
struct msm_drm_private *priv = dev->dev_private;
struct drm_gem_object *obj = NULL;
bool use_vram = false;
int ret;
- WARN_ON(!mutex_is_locked(&dev->struct_mutex));
-
size = PAGE_ALIGN(size);
if (!iommu_present(&platform_bus_type))
@@ -870,7 +921,7 @@ struct drm_gem_object *msm_gem_new(struct drm_device *dev,
if (size == 0)
return ERR_PTR(-EINVAL);
- ret = msm_gem_new_impl(dev, size, flags, NULL, &obj);
+ ret = msm_gem_new_impl(dev, size, flags, NULL, &obj, struct_mutex_locked);
if (ret)
goto fail;
@@ -904,10 +955,22 @@ struct drm_gem_object *msm_gem_new(struct drm_device *dev,
return obj;
fail:
- drm_gem_object_unreference(obj);
+ drm_gem_object_unreference_unlocked(obj);
return ERR_PTR(ret);
}
+struct drm_gem_object *msm_gem_new_locked(struct drm_device *dev,
+ uint32_t size, uint32_t flags)
+{
+ return _msm_gem_new(dev, size, flags, true);
+}
+
+struct drm_gem_object *msm_gem_new(struct drm_device *dev,
+ uint32_t size, uint32_t flags)
+{
+ return _msm_gem_new(dev, size, flags, false);
+}
+
struct drm_gem_object *msm_gem_import(struct drm_device *dev,
struct dma_buf *dmabuf, struct sg_table *sgt)
{
@@ -924,11 +987,7 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev,
size = PAGE_ALIGN(dmabuf->size);
- /* Take mutex so we can modify the inactive list in msm_gem_new_impl */
- mutex_lock(&dev->struct_mutex);
- ret = msm_gem_new_impl(dev, size, MSM_BO_WC, dmabuf->resv, &obj);
- mutex_unlock(&dev->struct_mutex);
-
+ ret = msm_gem_new_impl(dev, size, MSM_BO_WC, dmabuf->resv, &obj, false);
if (ret)
goto fail;
@@ -937,17 +996,22 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev,
npages = size / PAGE_SIZE;
msm_obj = to_msm_bo(obj);
+ mutex_lock(&msm_obj->lock);
msm_obj->sgt = sgt;
msm_obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
if (!msm_obj->pages) {
+ mutex_unlock(&msm_obj->lock);
ret = -ENOMEM;
goto fail;
}
ret = drm_prime_sg_to_page_addr_arrays(sgt, msm_obj->pages, NULL, npages);
- if (ret)
+ if (ret) {
+ mutex_unlock(&msm_obj->lock);
goto fail;
+ }
+ mutex_unlock(&msm_obj->lock);
return obj;
fail: