Re: [PATCH v5 03/11] drivers: of: add initialization code for dynamic reserved memory

[Grant Likely <grant.likely@linaro.org>]

On Fri, 21 Feb 2014 13:25:19 +0100, Marek Szyprowski <m.szyprowski@samsung.com> wrote:
> This patch adds support for dynamically allocated reserved memory regions
> declared in device tree. Such regions are defined by 'size', 'alignment'
> and 'alloc-ranges' properties.
> 
> Based on previous code provided by Josh Cartwright <joshc@codeaurora.org>
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

Acked-by: Grant Likely <grant.likely@linaro.org>

> ---
>  drivers/of/Kconfig              |    6 ++
>  drivers/of/Makefile             |    1 +
>  drivers/of/fdt.c                |   13 ++-
>  drivers/of/of_reserved_mem.c    |  188 +++++++++++++++++++++++++++++++++++++++
>  include/linux/of_reserved_mem.h |   21 +++++
>  5 files changed, 227 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/of/of_reserved_mem.c
>  create mode 100644 include/linux/of_reserved_mem.h
> 
> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> index c6973f101a3e..30a7d87a8077 100644
> --- a/drivers/of/Kconfig
> +++ b/drivers/of/Kconfig
> @@ -75,4 +75,10 @@ config OF_MTD
>  	depends on MTD
>  	def_bool y
>  
> +config OF_RESERVED_MEM
> +	depends on OF_EARLY_FLATTREE
> +	bool
> +	help
> +	  Helpers to allow for reservation of memory regions
> +
>  endmenu # OF
> diff --git a/drivers/of/Makefile b/drivers/of/Makefile
> index efd05102c405..ed9660adad77 100644
> --- a/drivers/of/Makefile
> +++ b/drivers/of/Makefile
> @@ -9,3 +9,4 @@ 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/fdt.c b/drivers/of/fdt.c
> index 12809e20ef71..eafe5805257a 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -15,6 +15,7 @@
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_fdt.h>
> +#include <linux/of_reserved_mem.h>
>  #include <linux/string.h>
>  #include <linux/errno.h>
>  #include <linux/slab.h>
> @@ -449,7 +450,7 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
>  	phys_addr_t base, size;
>  	unsigned long len;
>  	__be32 *prop;
> -	int nomap;
> +	int nomap, first = 1;
>  
>  	prop = of_get_flat_dt_prop(node, "reg", &len);
>  	if (!prop)
> @@ -476,6 +477,10 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
>  				uname, &base, (unsigned long)size / SZ_1M);
>  
>  		len -= t_len;
> +		if (first) {
> +			fdt_reserved_mem_save_node(node, uname, base, size);
> +			first = 0;
> +		}
>  	}
>  	return 0;
>  }
> @@ -506,6 +511,7 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
>  {
>  	static int found;
>  	const char *status;
> +	int err;
>  
>  	if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
>  		if (__reserved_mem_check_root(node) != 0) {
> @@ -528,7 +534,9 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
>  	if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
>  		return 0;
>  
> -	__reserved_mem_reserve_reg(node, uname);
> +	err = __reserved_mem_reserve_reg(node, uname);
> +	if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
> +		fdt_reserved_mem_save_node(node, uname, 0, 0);
>  
>  	/* scan next node */
>  	return 0;
> @@ -544,6 +552,7 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
>  void __init early_init_fdt_scan_reserved_mem(void)
>  {
>  	of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
> +	fdt_init_reserved_mem();
>  }
>  
>  /**
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> new file mode 100644
> index 000000000000..c7ca6a4a42d1
> --- /dev/null
> +++ b/drivers/of/of_reserved_mem.c
> @@ -0,0 +1,188 @@
> +/*
> + * Device tree based initialization code for reserved memory.
> + *
> + * 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@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/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/of_reserved_mem.h>
> +
> +#define MAX_RESERVED_REGIONS	16
> +static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
> +static int reserved_mem_count;
> +
> +#if defined(CONFIG_HAVE_MEMBLOCK)
> +#include <linux/memblock.h>
> +int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
> +	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
> +	phys_addr_t *res_base)
> +{
> +	/*
> +	 * We use __memblock_alloc_base() because memblock_alloc_base()
> +	 * panic()s on allocation failure.
> +	 */
> +	phys_addr_t base = __memblock_alloc_base(size, align, end);
> +	if (!base)
> +		return -ENOMEM;
> +
> +	/*
> +	 * Check if the allocated region fits in to start..end window
> +	 */
> +	if (base < start) {
> +		memblock_free(base, size);
> +		return -ENOMEM;
> +	}
> +
> +	*res_base = base;
> +	if (nomap)
> +		return memblock_remove(base, size);
> +	return 0;
> +}
> +#else
> +int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
> +	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
> +	phys_addr_t *res_base)
> +{
> +	pr_error("Reserved memory not supported, ignoring region 0x%llx%s\n",
> +		  size, nomap ? " (nomap)" : "");
> +	return -ENOSYS;
> +}
> +#endif
> +
> +/**
> + * res_mem_save_node() - save fdt node for second pass initialization
> + */
> +void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
> +				      phys_addr_t base, phys_addr_t size)
> +{
> +	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
> +
> +	if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
> +		pr_err("Reserved memory: not enough space all defined regions.\n");
> +		return;
> +	}
> +
> +	rmem->fdt_node = node;
> +	rmem->name = uname;
> +	rmem->base = base;
> +	rmem->size = size;
> +
> +	reserved_mem_count++;
> +	return;
> +}
> +
> +/**
> + * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
> + *			  and 'alloc-ranges' properties
> + */
> +static int __init __reserved_mem_alloc_size(unsigned long node,
> +	const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
> +{
> +	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
> +	phys_addr_t start = 0, end = 0;
> +	phys_addr_t base = 0, align = 0, size;
> +	unsigned long len;
> +	__be32 *prop;
> +	int nomap;
> +	int ret;
> +
> +	prop = of_get_flat_dt_prop(node, "size", &len);
> +	if (!prop)
> +		return -EINVAL;
> +
> +	if (len != dt_root_size_cells * sizeof(__be32)) {
> +		pr_err("Reserved memory: invalid size property in '%s' node.\n",
> +				uname);
> +		return -EINVAL;
> +	}
> +	size = dt_mem_next_cell(dt_root_size_cells, &prop);
> +
> +	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
> +
> +	prop = of_get_flat_dt_prop(node, "alignment", &len);
> +	if (prop) {
> +		if (len != dt_root_addr_cells * sizeof(__be32)) {
> +			pr_err("Reserved memory: invalid alignment property in '%s' node.\n",
> +				uname);
> +			return -EINVAL;
> +		}
> +		align = dt_mem_next_cell(dt_root_addr_cells, &prop);
> +	}
> +
> +	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
> +	if (prop) {
> +
> +		if (len % t_len != 0) {
> +			pr_err("Reserved memory: invalid alloc-ranges property in '%s', skipping node.\n",
> +			       uname);
> +			return -EINVAL;
> +		}
> +
> +		base = 0;
> +
> +		while (len > 0) {
> +			start = dt_mem_next_cell(dt_root_addr_cells, &prop);
> +			end = start + dt_mem_next_cell(dt_root_size_cells,
> +						       &prop);
> +
> +			ret = early_init_dt_alloc_reserved_memory_arch(size,
> +					align, start, end, nomap, &base);
> +			if (ret == 0) {
> +				pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
> +					uname, &base,
> +					(unsigned long)size / SZ_1M);
> +				break;
> +			}
> +			len -= t_len;
> +		}
> +
> +	} else {
> +		ret = early_init_dt_alloc_reserved_memory_arch(size, align,
> +							0, 0, nomap, &base);
> +		if (ret == 0)
> +			pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
> +				uname, &base, (unsigned long)size / SZ_1M);
> +	}
> +
> +	if (base == 0) {
> +		pr_info("Reserved memory: failed to allocate memory for node '%s'\n",
> +			uname);
> +		return -ENOMEM;
> +	}
> +
> +	*res_base = base;
> +	*res_size = size;
> +
> +	return 0;
> +}
> +
> +/**
> + * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
> + */
> +void __init fdt_init_reserved_mem(void)
> +{
> +	int i;
> +	for (i = 0; i < reserved_mem_count; i++) {
> +		struct reserved_mem *rmem = &reserved_mem[i];
> +		unsigned long node = rmem->fdt_node;
> +		int err = 0;
> +
> +		if (rmem->size == 0)
> +			err = __reserved_mem_alloc_size(node, rmem->name,
> +						 &rmem->base, &rmem->size);
> +	}
> +}
> diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
> new file mode 100644
> index 000000000000..89226ed7d954
> --- /dev/null
> +++ b/include/linux/of_reserved_mem.h
> @@ -0,0 +1,21 @@
> +#ifndef __OF_RESERVED_MEM_H
> +#define __OF_RESERVED_MEM_H
> +
> +struct reserved_mem {
> +	const char			*name;
> +	unsigned long			fdt_node;
> +	phys_addr_t			base;
> +	phys_addr_t			size;
> +};
> +
> +#ifdef CONFIG_OF_RESERVED_MEM
> +void fdt_init_reserved_mem(void);
> +void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
> +			       phys_addr_t base, phys_addr_t size);
> +#else
> +static inline void fdt_init_reserved_mem(void) { }
> +static inline void fdt_reserved_mem_save_node(unsigned long node,
> +		const char *uname, phys_addr_t base, phys_addr_t size) { }
> +#endif
> +
> +#endif /* __OF_RESERVED_MEM_H */
> -- 
> 1.7.9.5
>