From: Josh Cartwright joshc@codeaurora.org
Add support for handling 'shared-dma-pool' reserved-memory nodes using dma exclusive driver (dma_alloc_coherent()).
Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Laura Abbott lauraa@codeaurora.org Signed-off-by: Josh Cartwright joshc@codeaurora.org Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- drivers/of/Kconfig | 7 ++++ drivers/of/Makefile | 1 + drivers/of/of_reserved_mem_dma.c | 78 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 86 insertions(+) create mode 100644 drivers/of/of_reserved_mem_dma.c
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index aba13df56f3a..7ac330473ec9 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -81,4 +81,11 @@ 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..53a4cac6084a --- /dev/null +++ b/drivers/of/of_reserved_mem_dma.c @@ -0,0 +1,78 @@ +/* + * 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@samsung.com + * Author: Josh Cartwright joshc@codeaurora.org + * + * 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 = of_parse_flat_dt_reg(node, uname, &rmem->base, &rmem->size); + if (!err) + goto out_done; + + err = of_parse_flat_dt_size(node, uname, &rmem->size); + if (err) + goto out_err; + + rmem->base = memblock_alloc_base(rmem->size, PAGE_SIZE, + MEMBLOCK_ALLOC_ANYWHERE); + memblock_free(rmem->base, rmem->size); + +out_done: + 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); + + return memblock_remove(rmem->base, rmem->size); + +out_err: + 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);