Hi,
On 2/14/2013 4:45 AM, Marek Szyprowski wrote:
<snip>
+name: an name given to the defined region.
+base-address: the base address of the defined region.
+size: the size of the memory region.
+linux,contiguous-region: property indicating that the defined memory
+ region is used for contiguous memory allocations,
+ Linux specific (optional)
+linux,default-contiguous-region: property indicating that the region
+ is the default region for all contiguous memory
+ allocations, Linux specific (optional)
+
+
I don't see any code actually implementing the default-contiguous-region
binding. Currently on ARM systems we will still setup the default region
based on the Kconfig. Is this intentional?
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index 085389c..5761f73 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -24,6 +24,9 @@
#include <linux/memblock.h>
#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/page-isolation.h>
@@ -177,6 +180,35 @@ no_mem:
return ERR_PTR(ret);
}
+/*****************************************************************************/
+
+#ifdef CONFIG_OF
+int __init cma_fdt_scan(unsigned long node, const char *uname,
+ int depth, void *data)
+{
+ phys_addr_t base, size;
+ unsigned long len;
+ __be32 *prop;
+
+ if (strncmp(uname, "region@", 7) != 0 || depth != 2 ||
+ !of_get_flat_dt_prop(node, "contiguous-region", NULL))
The documentation says "linux,contiguous-region"
+#ifdef CONFIG_OF
+static void cma_assign_device_from_dt(struct device *dev)
+{
+ struct device_node *node;
+ struct cma *cma;
+ u32 value;
+
+ node = of_parse_phandle(dev->of_node, "linux,contiguous-region", 0);
+ if (!node)
+ return;
+ if (of_property_read_u32(node, "reg", &value) && !value)
+ return;
+ cma = cma_get_area(value);
+ if (!cma)
+ return;
+
+ dev_set_cma_area(dev, cma);
+ pr_info("Assigned CMA region at %lx to %s device\n", (unsigned
long)value, dev_name(dev));
+}
+
This scheme of associating devices with CMA regions by base does not
work if you want to let CMA figure out where to place the region (base =
0). Can we use the name to associate the device with the region? I had
been working on something similar internally and that was the only
solution I had come up with to associate arbitrary CMA nodes with devices.
Thanks,
Laura
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation
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