21 Feb
2012
21 Feb
'12
9:30 p.m.
Hi,
On Fri, 17 Feb 2012, Marek Szyprowski wrote:
+/**
- dma_release_from_contiguous() - release allocated pages
- @dev: Pointer to device for which the pages were allocated.
- @pages: Allocated pages.
- @count: Number of allocated pages.
- This function releases memory allocated by dma_alloc_from_contiguous().
- It returns false when provided pages do not belong to contiguous area and
- true otherwise.
- */
+bool dma_release_from_contiguous(struct device *dev, struct page *pages,
int count)+{
- struct cma *cma = dev_get_cma_area(dev);
- unsigned long pfn;
- if (!cma || !pages)
return false;- pr_debug("%s(page %p)\n", __func__, (void *)pages);
- pfn = page_to_pfn(pages);
- if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count)
return false;- VM_BUG_ON(pfn + count > cma->base_pfn);
Are you sure the VM_BUG_ON() condition is correct here?
- mutex_lock(&cma_mutex);
- bitmap_clear(cma->bitmap, pfn - cma->base_pfn, count);
- free_contig_range(pfn, count);
- mutex_unlock(&cma_mutex);
- return true;
+}
A.