[PATCH v2 3/5] drivers: of: implement reserved-memory handling for cma

From: Marek Szyprowski
Date: Tue Feb 04 2014 - 07:10:29 EST


From: Josh Cartwright <joshc@xxxxxxxxxxxxxx>

Add support for handling 'shared-dma-pool' reserved-memory nodes using
Contiguous Memory Allocator driver.

Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Laura Abbott <lauraa@xxxxxxxxxxxxxx>
Signed-off-by: Josh Cartwright <joshc@xxxxxxxxxxxxxx>
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
drivers/of/Kconfig | 7 ++++
drivers/of/Makefile | 1 +
drivers/of/of_reserved_mem_cma.c | 75 ++++++++++++++++++++++++++++++++++++++
3 files changed, 83 insertions(+)
create mode 100644 drivers/of/of_reserved_mem_cma.c

diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 7ac330473ec9..5dd3a80910d2 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -81,6 +81,13 @@ config OF_RESERVED_MEM
help
Helpers to allow for reservation of memory regions

+config OF_RESERVED_MEM_CMA
+ depends on OF_RESERVED_MEM
+ depends on DMA_CMA
+ def_bool y
+ help
+ Helpers for reserving memory regions for DMA use
+
config OF_RESERVED_MEM_DMA
depends on OF_RESERVED_MEM
depends on HAVE_GENERIC_DMA_COHERENT
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index 6142227ca854..49b9078637b8 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -10,4 +10,5 @@ obj-$(CONFIG_OF_PCI) += of_pci.o
obj-$(CONFIG_OF_PCI_IRQ) += of_pci_irq.o
obj-$(CONFIG_OF_MTD) += of_mtd.o
obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
+obj-$(CONFIG_OF_RESERVED_MEM_CMA) += of_reserved_mem_cma.o
obj-$(CONFIG_OF_RESERVED_MEM_DMA) += of_reserved_mem_dma.o
diff --git a/drivers/of/of_reserved_mem_cma.c b/drivers/of/of_reserved_mem_cma.c
new file mode 100644
index 000000000000..601d80655102
--- /dev/null
+++ b/drivers/of/of_reserved_mem_cma.c
@@ -0,0 +1,75 @@
+/*
+ * Device tree based initialization code for DMA reserved regions.
+ *
+ * Copyright (c) 2013, The Linux Foundation. All Rights Reserved.
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com
+ * Author: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
+ * Author: Josh Cartwright <joshc@xxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License or (at your optional) any later version of the license.
+ */
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+#include <linux/mm.h>
+#include <linux/sizes.h>
+#include <linux/mm_types.h>
+#include <linux/dma-contiguous.h>
+#include <linux/of_reserved_mem.h>
+
+static void rmem_cma_device_init(struct reserved_mem *rmem,
+ struct device *dev,
+ struct of_phandle_args *args)
+{
+ struct cma *cma = rmem->priv;
+ dev_set_cma_area(dev, cma);
+}
+
+static const struct reserved_mem_ops rmem_cma_ops = {
+ .device_init = rmem_cma_device_init,
+};
+
+static int __init rmem_cma_setup(struct reserved_mem *rmem,
+ unsigned long node,
+ const char *uname)
+{
+ struct cma *cma;
+ int err;
+
+ if (!of_get_flat_dt_prop(node, "reusable", NULL))
+ return -EINVAL;
+
+ err = of_parse_flat_dt_reg(node, uname, &rmem->base, &rmem->size);
+ if (!err)
+ goto out_done;
+
+ rmem->base = 0;
+ err = of_parse_flat_dt_size(node, uname, &rmem->size);
+ if (err)
+ goto out_err;
+
+out_done:
+ err = dma_contiguous_reserve_area(rmem->size, rmem->base, 0,
+ &cma);
+ if (err) {
+ pr_err("Reserved memory: unable to setup CMA region\n");
+ return err;
+ }
+
+ if (of_get_flat_dt_prop(node, "linux,cma-default", NULL))
+ dma_contiguous_set_default(cma);
+
+ rmem->ops = &rmem_cma_ops;
+ rmem->priv = cma;
+
+ return 0;
+out_err:
+ pr_err("Reseved memory: malformed node '%s'.\n", uname);
+ return err;
+}
+RESERVEDMEM_OF_DECLARE(cma, "shared-dma-pool", rmem_cma_setup);
--
1.7.9.5

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