Revert "drivers: of: add initialization code for dma reserved memory"

This reverts commit 9d8eab7af79cb4ce2de5de39f82c455b1f796963. There is
still no consensus on the bindings for the reserved memory and various
drawbacks of the proposed solution has been shown, so the best now is to
revert it completely and start again from scratch later.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

4 files changed, 0 insertions, 184 deletions

diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 9d2009a9004..78cc7605332 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -74,10 +74,4 @@ config OF_MTD
 	depends on MTD
 	def_bool y
 
-config OF_RESERVED_MEM
-	depends on OF_FLATTREE && (DMA_CMA || (HAVE_GENERIC_DMA_COHERENT && HAVE_MEMBLOCK))
-	def_bool y
-	help
-	  Initialization code for DMA reserved memory
-
 endmenu # OF
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index ed9660adad7..efd05102c40 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -9,4 +9,3 @@ obj-$(CONFIG_OF_MDIO)	+= of_mdio.o
 obj-$(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
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
deleted file mode 100644
index 0fe40c7d690..00000000000
--- a/drivers/of/of_reserved_mem.c
+++ /dev/null
@@ -1,173 +0,0 @@
-/*
- * Device tree based initialization code for reserved memory.
- *
- * Copyright (c) 2013 Samsung Electronics Co., Ltd.
- *		http://www.samsung.com
- * Author: Marek Szyprowski <m.szyprowski@samsung.com>
- *
- * 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-contiguous.h>
-#include <linux/dma-mapping.h>
-#include <linux/of_reserved_mem.h>
-
-#define MAX_RESERVED_REGIONS	16
-struct reserved_mem {
-	phys_addr_t		base;
-	unsigned long		size;
-	struct cma		*cma;
-	char			name[32];
-};
-static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
-static int reserved_mem_count;
-
-static int __init fdt_scan_reserved_mem(unsigned long node, const char *uname,
-					int depth, void *data)
-{
-	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
-	phys_addr_t base, size;
-	int is_cma, is_reserved;
-	unsigned long len;
-	const char *status;
-	__be32 *prop;
-
-	is_cma = IS_ENABLED(CONFIG_DMA_CMA) &&
-	       of_flat_dt_is_compatible(node, "linux,contiguous-memory-region");
-	is_reserved = of_flat_dt_is_compatible(node, "reserved-memory-region");
-
-	if (!is_reserved && !is_cma) {
-		/* ignore node and scan next one */
-		return 0;
-	}
-
-	status = of_get_flat_dt_prop(node, "status", &len);
-	if (status && strcmp(status, "okay") != 0) {
-		/* ignore disabled node nad scan next one */
-		return 0;
-	}
-
-	prop = of_get_flat_dt_prop(node, "reg", &len);
-	if (!prop || (len < (dt_root_size_cells + dt_root_addr_cells) *
-			     sizeof(__be32))) {
-		pr_err("Reserved mem: node %s, incorrect \"reg\" property\n",
-		       uname);
-		/* ignore node and scan next one */
-		return 0;
-	}
-	base = dt_mem_next_cell(dt_root_addr_cells, &prop);
-	size = dt_mem_next_cell(dt_root_size_cells, &prop);
-
-	if (!size) {
-		/* ignore node and scan next one */
-		return 0;
-	}
-
-	pr_info("Reserved mem: found %s, memory base %lx, size %ld MiB\n",
-		uname, (unsigned long)base, (unsigned long)size / SZ_1M);
-
-	if (reserved_mem_count == ARRAY_SIZE(reserved_mem))
-		return -ENOSPC;
-
-	rmem->base = base;
-	rmem->size = size;
-	strlcpy(rmem->name, uname, sizeof(rmem->name));
-
-	if (is_cma) {
-		struct cma *cma;
-		if (dma_contiguous_reserve_area(size, base, 0, &cma) == 0) {
-			rmem->cma = cma;
-			reserved_mem_count++;
-			if (of_get_flat_dt_prop(node,
-						"linux,default-contiguous-region",
-						NULL))
-				dma_contiguous_set_default(cma);
-		}
-	} else if (is_reserved) {
-		if (memblock_remove(base, size) == 0)
-			reserved_mem_count++;
-		else
-			pr_err("Failed to reserve memory for %s\n", uname);
-	}
-
-	return 0;
-}
-
-static struct reserved_mem *get_dma_memory_region(struct device *dev)
-{
-	struct device_node *node;
-	const char *name;
-	int i;
-
-	node = of_parse_phandle(dev->of_node, "memory-region", 0);
-	if (!node)
-		return NULL;
-
-	name = kbasename(node->full_name);
-	for (i = 0; i < reserved_mem_count; i++)
-		if (strcmp(name, reserved_mem[i].name) == 0)
-			return &reserved_mem[i];
-	return NULL;
-}
-
-/**
- * of_reserved_mem_device_init() - assign reserved memory region to given device
- *
- * This function assign memory region pointed by "memory-region" device tree
- * property to the given device.
- */
-void of_reserved_mem_device_init(struct device *dev)
-{
-	struct reserved_mem *region = get_dma_memory_region(dev);
-	if (!region)
-		return;
-
-	if (region->cma) {
-		dev_set_cma_area(dev, region->cma);
-		pr_info("Assigned CMA %s to %s device\n", region->name,
-			dev_name(dev));
-	} else {
-		if (dma_declare_coherent_memory(dev, region->base, region->base,
-		    region->size, DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE) != 0)
-			pr_info("Declared reserved memory %s to %s device\n",
-				region->name, dev_name(dev));
-	}
-}
-
-/**
- * of_reserved_mem_device_release() - release reserved memory device structures
- *
- * This function releases structures allocated for memory region handling for
- * the given device.
- */
-void of_reserved_mem_device_release(struct device *dev)
-{
-	struct reserved_mem *region = get_dma_memory_region(dev);
-	if (!region && !region->cma)
-		dma_release_declared_memory(dev);
-}
-
-/**
- * early_init_dt_scan_reserved_mem() - create reserved memory regions
- *
- * This function grabs memory from early allocator for device exclusive use
- * defined in device tree structures. It should be called by arch specific code
- * once the early allocator (memblock) has been activated and all other
- * subsystems have already allocated/reserved memory.
- */
-void __init early_init_dt_scan_reserved_mem(void)
-{
-	of_scan_flat_dt_by_path("/memory/reserved-memory",
-				fdt_scan_reserved_mem, NULL);
-}
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 9b439ac63d8..f6dcde22082 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -21,7 +21,6 @@
 #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[] = {
@@ -219,8 +218,6 @@ static 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
@@ -228,7 +225,6 @@ static 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;
 	}