[Linaro-mm-sig] [PATCH 12/15] drivers: add Contiguous Memory Allocator
From: Ohad Ben-Cohen <hidden>
Date: 2012-01-28 18:57:36
Also in:
linux-media, linux-mm, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
Hi Marek, On Fri, Jan 27, 2012 at 5:17 PM, Marek Szyprowski [off-list ref] wrote:
There have been some vmalloc layout changes merged to v3.3-rc1.
That was dead-on, thanks a lot! I did then bump into a different allocation failure which happened because dma_alloc_from_contiguous() computes 'mask' before capping the 'align' argument. The early 'mask' computation was added in v18 (and therefore exists in v19 too) and I was actually testing v17 previously, so I didn't notice it before. You may want to squash something like this:
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index f41e699..8455cb7 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c@@ -319,8 +319,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, i unsigned int align) { struct cma *cma = dev_get_cma_area(dev); - unsigned long pfn, pageno, start = 0; - unsigned long mask = (1 << align) - 1; + unsigned long mask, pfn, pageno, start = 0; int ret; if (!cma || !cma->count)
@@ -329,6 +328,8 @@ struct page *dma_alloc_from_contiguous(struct device *dev, i if (align > CONFIG_CMA_ALIGNMENT) align = CONFIG_CMA_ALIGNMENT; + mask = (1 << align) - 1; + pr_debug("%s(cma %p, count %d, align %d)\n", __func__, (void *)cma, count, align);
Thanks, Ohad.