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drivers: of: add initialization code for dma reserved memory

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This patch adds device tree support for contiguous and reserved memory
regions defined in device tree.

Large memory blocks can be reliably reserved only during early boot.
This must happen before the whole memory management subsystem is
initialized, because we need to ensure that the given contiguous blocks
are not yet allocated by kernel. Also it must happen before kernel
mappings for the whole low memory are created, to ensure that there will
be no mappings (for reserved blocks) or mapping with special properties
can be created (for CMA blocks). This all happens before device tree
structures are unflattened, so we need to get reserved memory layout
directly from fdt.

Later, those reserved memory regions are assigned to devices on each
device structure initialization.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Tomasz Figa <t.figa@samsung.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
This commit is contained in:
Marek Szyprowski
2013-08-26 14:43:10 +02:00
parent 57d74bcf30
commit 9d8eab7af7
6 changed files with 368 additions and 0 deletions
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4
drivers/of/platform.c
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@@ -21,6 +21,7 @@
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
const struct of_device_id of_default_bus_match_table[] = {
@@ -218,6 +219,8 @@ struct platform_device *of_platform_device_create_pdata(
dev->dev.bus = &platform_bus_type;
dev->dev.platform_data = platform_data;
of_reserved_mem_device_init(&dev->dev);
/* We do not fill the DMA ops for platform devices by default.
* This is currently the responsibility of the platform code
* to do such, possibly using a device notifier
@@ -225,6 +228,7 @@ struct platform_device *of_platform_device_create_pdata(
if (of_device_add(dev) != 0) {
platform_device_put(dev);
of_reserved_mem_device_release(&dev->dev);
return NULL;
}