Re: [Linaro-mm-sig] [PATCHv3 07/22] staging: android: ion: Remove page faulting support

Hi,

On 04/04/2017 12:27 AM, Laura Abbott wrote:

The new method of syncing with dma_map means that the page faulting sync implementation is no longer applicable. Remove it.

Signed-off-by: Laura Abbott labbott@redhat.com

drivers/staging/android/ion/ion.c | 117 -------------------------------------- 1 file changed, 117 deletions(-)

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 6aac935..226ea1f 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -42,37 +42,11 @@ #include "ion_priv.h" #include "compat_ion.h"

-bool ion_buffer_fault_user_mappings(struct ion_buffer *buffer) -{

• return (buffer->flags & ION_FLAG_CACHED) &&

• !(buffer->flags & ION_FLAG_CACHED_NEEDS_SYNC);
  

-}

bool ion_buffer_cached(struct ion_buffer *buffer) { return !!(buffer->flags & ION_FLAG_CACHED); }

-static inline struct page *ion_buffer_page(struct page *page) -{

• return (struct page *)((unsigned long)page & ~(1UL));

-}

-static inline bool ion_buffer_page_is_dirty(struct page *page) -{

• return !!((unsigned long)page & 1UL);

-}

-static inline void ion_buffer_page_dirty(struct page **page) -{

• *page = (struct page *)((unsigned long)(*page) | 1UL);

-}

-static inline void ion_buffer_page_clean(struct page **page) -{

• *page = (struct page *)((unsigned long)(*page) & ~(1UL));

-}

/* this function should only be called while dev->lock is held */ static void ion_buffer_add(struct ion_device *dev, struct ion_buffer *buffer) @@ -140,25 +114,6 @@ static struct ion_buffer *ion_buffer_create(struct ion_heap *heap, buffer->dev = dev; buffer->size = len;

• if (ion_buffer_fault_user_mappings(buffer)) {

• int num_pages = PAGE_ALIGN(buffer->size) / PAGE_SIZE;
  

• struct scatterlist *sg;
  

• int i, j, k = 0;
  

• buffer->pages = vmalloc(sizeof(struct page *) * num_pages);
  

We should also remove the vfree(buffer->pages) call in ion_buffer_destroy. In fact, we could removes 'pages' member from ion_buffer altogether.

Thanks, Archit

• if (!buffer->pages) {
  

• 	ret = -ENOMEM;
  

• 	goto err1;
  

• }
  

• for_each_sg(table->sgl, sg, table->nents, i) {
  

• 	struct page *page = sg_page(sg);
  

• 	for (j = 0; j < sg->length / PAGE_SIZE; j++)
  

• 		buffer->pages[k++] = page++;
  

• }
  

• }
• buffer->dev = dev; buffer->size = len; INIT_LIST_HEAD(&buffer->vmas);

@@ -924,69 +879,6 @@ void ion_pages_sync_for_device(struct device *dev, struct page *page, dma_sync_sg_for_device(dev, &sg, 1, dir); }

-struct ion_vma_list {

• struct list_head list;
• struct vm_area_struct *vma;

-};

-static int ion_vm_fault(struct vm_fault *vmf) -{

• struct ion_buffer *buffer = vmf->vma->vm_private_data;
• unsigned long pfn;
• int ret;
• mutex_lock(&buffer->lock);
• ion_buffer_page_dirty(buffer->pages + vmf->pgoff);
• BUG_ON(!buffer->pages || !buffer->pages[vmf->pgoff]);
• pfn = page_to_pfn(ion_buffer_page(buffer->pages[vmf->pgoff]));
• ret = vm_insert_pfn(vmf->vma, vmf->address, pfn);
• mutex_unlock(&buffer->lock);
• if (ret)

• return VM_FAULT_ERROR;
  

• return VM_FAULT_NOPAGE;

-}

-static void ion_vm_open(struct vm_area_struct *vma) -{

• struct ion_buffer *buffer = vma->vm_private_data;
• struct ion_vma_list *vma_list;
• vma_list = kmalloc(sizeof(*vma_list), GFP_KERNEL);
• if (!vma_list)

• return;
  

• vma_list->vma = vma;
• mutex_lock(&buffer->lock);
• list_add(&vma_list->list, &buffer->vmas);
• mutex_unlock(&buffer->lock);
• pr_debug("%s: adding %p\n", __func__, vma);

-}

-static void ion_vm_close(struct vm_area_struct *vma) -{

• struct ion_buffer *buffer = vma->vm_private_data;
• struct ion_vma_list *vma_list, *tmp;
• pr_debug("%s\n", __func__);
• mutex_lock(&buffer->lock);
• list_for_each_entry_safe(vma_list, tmp, &buffer->vmas, list) {

• if (vma_list->vma != vma)
  

• 	continue;
  

• list_del(&vma_list->list);
  

• kfree(vma_list);
  

• pr_debug("%s: deleting %p\n", __func__, vma);
  

• break;
  

• }
• mutex_unlock(&buffer->lock);

-}

-static const struct vm_operations_struct ion_vma_ops = {

• .open = ion_vm_open,
• .close = ion_vm_close,
• .fault = ion_vm_fault,

-};

static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) { struct ion_buffer *buffer = dmabuf->priv; @@ -998,15 +890,6 @@ static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) return -EINVAL; }

• if (ion_buffer_fault_user_mappings(buffer)) {

• vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND |
  

• 					VM_DONTDUMP;
  

• vma->vm_private_data = buffer;
  

• vma->vm_ops = &ion_vma_ops;
  

• ion_vm_open(vma);
  

• return 0;
  

• }
• if (!(buffer->flags & ION_FLAG_CACHED)) vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);