Hello,
On 2014-02-18 17:58, Grant Likely wrote:
On Tue, 18 Feb 2014 14:37:58 +0100, Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> wrote:
> From: Josh Cartwright <joshc@xxxxxxxxxxxxxx>
>
> Add support for handling 'shared-dma-pool' reserved-memory nodes using
> dma exclusive driver (dma_alloc_coherent()).
>
> 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_dma.c | 65 ++++++++++++++++++++++++++++++++++++++
I don't see any reason to have this separate from of_reserved_mem.c
Some architectures don't have support for dma_declare_coherent_memory()
(CONFIG_HAVE_GENERIC_DMA_COHERENT), good examples are arc, c6x, metag
and extensa.
This code will not work for them.
> 3 files changed, 73 insertions(+)
> create mode 100644 drivers/of/of_reserved_mem_dma.c
>
> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> index f25931dfc6db..7f00b801bcd2 100644
> --- a/drivers/of/Kconfig
> +++ b/drivers/of/Kconfig
> @@ -80,4 +80,11 @@ config OF_RESERVED_MEM
> help
> Helpers to allow for reservation of memory regions
>
> +config OF_RESERVED_MEM_DMA
> + depends on OF_RESERVED_MEM
> + depends on HAVE_GENERIC_DMA_COHERENT
> + def_bool y
> + help
> + Helpers for reserving memory regions for DMA use
> +
> endmenu # OF
> diff --git a/drivers/of/Makefile b/drivers/of/Makefile
> index ed9660adad77..6142227ca854 100644
> --- a/drivers/of/Makefile
> +++ b/drivers/of/Makefile
> @@ -10,3 +10,4 @@ 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_DMA) += of_reserved_mem_dma.o
> diff --git a/drivers/of/of_reserved_mem_dma.c b/drivers/of/of_reserved_mem_dma.c
> new file mode 100644
> index 000000000000..a3e596d1091d
> --- /dev/null
> +++ b/drivers/of/of_reserved_mem_dma.c
> @@ -0,0 +1,65 @@
> +/*
> + * Device tree based initialization code for DMA reserved regions.
> + *
> + * Copyright (c) 2013, The Linux Foundation. All Rights Reserved.
> + * Copyright (c) 2013,2014 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/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/sizes.h>
> +#include <linux/mm_types.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/of_reserved_mem.h>
> +
> +static void rmem_dma_device_init(struct reserved_mem *rmem,
> + struct device *dev,
> + struct of_phandle_args *args)
> +{
> + dma_declare_coherent_memory(dev, rmem->base, rmem->base,
> + rmem->size, DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE);
> +}
> +
> +static void rmem_dma_device_release(struct reserved_mem *rmem,
> + struct device *dev)
> +{
> + dma_release_declared_memory(dev);
> +}
> +
> +static const struct reserved_mem_ops rmem_dma_ops = {
> + .device_init = rmem_dma_device_init,
> + .device_release = rmem_dma_device_release,
> +};
> +
> +static int __init rmem_dma_setup(struct reserved_mem *rmem,
> + unsigned long node,
> + const char *uname)
> +{
> + int err;
> +
> + if (of_get_flat_dt_prop(node, "reusable", NULL))
> + return -EINVAL;
> +
> + err = memblock_remove(rmem->base, rmem->size);
Isn't the memblock_remove() now handled by the core code? Or am I
mis-reading it?
I forgot to remove it...
> + if (err == 0) {
> + rmem->ops = &rmem_dma_ops;
> + pr_info("Reserved memory: created DMA memory pool at %pa, size %ld MiB\n",
> + &rmem->base, (unsigned long)rmem->size / SZ_1M);
> + } else {
> + pr_err("Reserved memory: unable to setup '%s' memory region for DMA.\n",
> + uname);
> + }
> + return err;
> +}
> +RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup);
> --
> 1.7.9.5
>
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
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