Hello,
On 2014-02-18 17:56, Grant Likely wrote:
On Tue, 18 Feb 2014 14:37:57 +0100, Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> wrote:
> This patch adds device tree support for contiguous and reserved memory
> regions defined in device tree.
>
> Large memory blocks can be reliably reserved only during early boot.
> This must happen before the whole memory management subsystem is
> initialized, because we need to ensure that the given contiguous blocks
> are not yet allocated by kernel. Also it must happen before kernel
> mappings for the whole low memory are created, to ensure that there will
> be no mappings (for reserved blocks) or mapping with special properties
> can be created (for CMA blocks). This all happens before device tree
> structures are unflattened, so we need to get reserved memory layout
> directly from fdt.
>
> Later, those reserved memory regions are assigned to devices on each
> device structure initialization.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> [joshc: rework to implement new DT binding, provide mechanism for
> plugging in new reserved-memory node handlers via
> RESERVEDMEM_OF_DECLARE]
> Signed-off-by: Josh Cartwright <joshc@xxxxxxxxxxxxxx>
> [mszyprow: added generic memory reservation code]
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> ---
> drivers/of/Kconfig | 5 +
> drivers/of/Makefile | 1 +
> drivers/of/fdt.c | 2 +
> drivers/of/of_reserved_mem.c | 390 +++++++++++++++++++++++++++++++++++++
> drivers/of/platform.c | 7 +
> include/asm-generic/vmlinux.lds.h | 11 ++
> include/linux/of_reserved_mem.h | 65 +++++++
> 7 files changed, 481 insertions(+)
> 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..f25931dfc6db 100644
> --- a/drivers/of/Kconfig
> +++ b/drivers/of/Kconfig
> @@ -75,4 +75,9 @@ config OF_MTD
> depends on MTD
> def_bool y
>
> +config OF_RESERVED_MEM
> + 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
As mentioned previously, parts of this are absolutely non-optional and
cannot be compiled out. If a region is marked as reserved with this
binding, then the kernel must respect it. That part of the code must be
always configured in.
How can I make it non-optional if all this code must be called from arch
specific early-boot init code to properly reserve memory. Do you want me
to add those calls to every architecture which supports OF?
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index 758b4f8b30b7..c205c84e51a1 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>
> @@ -907,6 +908,7 @@ void __init unflatten_device_tree(void)
>
> /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
> of_alias_scan(early_init_dt_alloc_memory_arch);
> + of_reserved_mem_scan();
> }
>
> /**
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> new file mode 100644
> index 000000000000..074d66e41da8
> --- /dev/null
> +++ b/drivers/of/of_reserved_mem.c
> @@ -0,0 +1,390 @@
> +/*
> + * 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@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/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_reserve_memory_arch(phys_addr_t base, phys_addr_t size,
> + bool nomap)
> +{
> + if (memblock_is_region_reserved(base, size))
> + return -EBUSY;
> + if (nomap)
> + return memblock_remove(base, size);
> + return memblock_reserve(base, size);
> +}
> +
> +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() since memblock_alloc_base() panic()s.
> + */
> + phys_addr_t base = __memblock_alloc_base(size, align, end);
> + if (!base)
> + return -ENOMEM;
Just realized this; this is actually a problem because an allocated
range may end up conflicting with a static range. Reservations must be
done in two passes. First pass should handle static ranges. Second pass
for doing dynamic allocations.
Right... I will check if it is possible to avoid dual-pass, because we are
already parsing all nodes stored in FDT, what might be time consuming.
> +
> + 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_reserve_memory_arch(phys_addr_t base, phys_addr_t size,
> + bool nomap)
> +{
> + pr_error("Reserved memory not supported, ignoring range 0x%llx - 0x%llx%s\n",
> + base, size, nomap ? " (nomap)" : "");
> + return -ENOSYS;
> +}
> +
> +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_reserve_reg() - reserve all memory described in 'reg' property
> + */
> +static int __init
> +res_mem_reserve_reg(unsigned long node, const char *uname, int nomap,
> + 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 base, size;
> + unsigned long len;
> + __be32 *prop;
> +
> + prop = of_get_flat_dt_prop(node, "reg", &len);
> + if (!prop)
> + return -ENOENT;
> +
> + if (len && len % t_len != 0) {
> + pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
> + uname);
> + return -EINVAL;
> + }
> +
> + /* store base and size values from the first reg tuple */
> + *res_base = 0;
> + while (len > 0) {
> + base = dt_mem_next_cell(dt_root_addr_cells, &prop);
> + size = dt_mem_next_cell(dt_root_size_cells, &prop);
> +
> + if (base && size &&
> + early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
> + pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
> + uname, &base, (unsigned long)size / SZ_1M);
> + else
> + pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
> + uname, &base, (unsigned long)size / SZ_1M);
> +
> + len -= t_len;
> +
> + if (!(*res_base)) {
> + *res_base = base;
> + *res_size = size;
> + }
> + }
> + return 0;
> +}
> +
> +/**
> + * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
> + * and 'alloc-ranges' properties
> + */
> +static int __init
> +res_mem_alloc_size(unsigned long node, const char *uname, int nomap,
> + 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 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);
> +
> + prop = of_get_flat_dt_prop(node, "align", &len);
> + if (prop) {
> + if (len != dt_root_addr_cells * sizeof(__be32)) {
> + pr_err("Reserved memory: invalid align 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;
> +}
> +
> +static const struct of_device_id __rmem_of_table_sentinel
> + __used __section(__reservedmem_of_table_end);
> +
> +/**
> + * res_mem_init_node() - call region specific reserved memory init code
> + */
> +static int __init
> +res_mem_init_node(unsigned long node, const char *uname, phys_addr_t base,
> + phys_addr_t size)
> +{
> + struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
> + extern const struct of_device_id __reservedmem_of_table[];
> + const struct of_device_id *i;
> +
> + if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
> + pr_err("Reserved memory: not enough space all defined regions.\n");
> + return -ENOSPC;
> + }
> +
> + rmem->base = base;
> + rmem->size = size;
> +
> + for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
> + reservedmem_of_init_fn initfn = i->data;
> + const char *compat = i->compatible;
> +
> + if (!of_flat_dt_is_compatible(node, compat))
> + continue;
> +
> + if (initfn(rmem, node, uname) == 0) {
> + pr_info("Reserved memory: initialized node %s, compatible id %s\n",
> + uname, compat);
> + rmem->name = uname;
> + reserved_mem_count++;
> + return 0;
> + }
> + }
> + return -EINVAL;
> +}
> +
> +/**
> + * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
> + */
> +static int __init
> +fdt_scan_reserved_mem(unsigned long node, const char *uname, int depth,
> + void *data)
> +{
> + phys_addr_t base, size;
> + const char *status;
> + int nomap;
> + int err;
> +
> + status = of_get_flat_dt_prop(node, "status", NULL);
> + if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
> + return 0;
> +
> + nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
> +
> + err = res_mem_reserve_reg(node, uname, nomap, &base, &size);
> + if (err == -ENOENT)
> + err = res_mem_alloc_size(node, uname, nomap, &base, &size);
> + if (err)
> + goto end;
> +
> + res_mem_init_node(node, uname, base, size);
> +end:
> + /* scan next node */
> + return 0;
> +}
> +
> +/**
> + * 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 (i.e. memblock) has been fully activated.
> + */
> +void __init early_init_dt_scan_reserved_mem(void)
> +{
> + of_scan_flat_dt_by_path("/reserved-memory", fdt_scan_reserved_mem,
> + NULL);
> +}
Just about everything above this point must be moved to fdt.c. Processing the
static reserved regions must be non-optional code. You can factor out
the table of reserved regions if you like, but I want the core
functionality directly in fdt.c.
Ok, I will move it then.
The dynamic allocation code can be optional, but that is because it
describes dynamic regions that have no possibility of hardware already
using them.
> +
> +/**
> + * of_reserved_mem_scan() - scan and create structures required by reserved
> + * memory regions
> + *
> + * This function creates all structures required by reserved memory regions
> + * management code. It should be called by common code once the device tree
> + * has been unflattened.
> + */
> +void __init of_reserved_mem_scan(void)
> +{
> + struct device_node *root, *np;
> +
> + root = of_find_node_by_path("/reserved-memory");
> +
> + if (of_n_addr_cells(root) != dt_root_addr_cells ||
> + of_n_size_cells(root) != dt_root_size_cells)
> + panic("Unsupported address or size cells for /reserved-memory node\n");
> +
> + for (np = NULL;;) {
> + const char *name;
> + int i;
> +
> + np = of_get_next_available_child(root, np);
> + if (!np)
> + break;
> +
> + name = kbasename(np->full_name);
> + for (i = 0; i < reserved_mem_count; i++)
> + if (strcmp(name, reserved_mem[i].name) == 0)
> + reserved_mem[i].node = np;
I've already commented on the above. kbasename is not a safe match.
Then please point me anything better to match FDT node with the
unflattened one. There
is no need to match the whole path, because both names comes from
'/reserved-memory'
node (one from FTD, one from unflattened structure).
> + }
> +}
> +
> +static inline struct reserved_mem *find_rmem(struct device_node *phandle)
> +{
> + unsigned int i;
> + for (i = 0; i < reserved_mem_count; i++)
> + if (reserved_mem[i].node == phandle)
> + 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 device_node *np = dev->of_node;
> + struct reserved_mem *rmem;
> + struct of_phandle_args s;
> + unsigned int i;
> +
> + for (i = 0; of_parse_phandle_with_args(np, "memory-region",
> + "#memory-region-cells", i, &s) == 0; i++) {
> +
> + rmem = find_rmem(s.np);
> + if (!rmem || !rmem->ops || !rmem->ops->device_init) {
> + of_node_put(s.np);
> + continue;
> + }
> +
> + rmem->ops->device_init(rmem, dev, &s);
> + dev_info(dev, "assigned reserved memory node %s\n",
> + rmem->name);
> + of_node_put(s.np);
> + break;
> + }
> +}
> +
> +/**
> + * 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 device_node *np = dev->of_node;
> + struct reserved_mem *rmem;
> + struct of_phandle_args s;
> + unsigned int i;
> +
> + for (i = 0; of_parse_phandle_with_args(np, "memory-region",
> + "#memory-region-cells", i, &s) == 0; i++) {
> +
> + rmem = find_rmem(s.np);
> + if (rmem && rmem->ops && rmem->ops->device_release)
> + rmem->ops->device_release(rmem, dev);
> +
> + of_node_put(s.np);
> + }
> +}
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 404d1daebefa..3df0b1826e8b 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -21,6 +21,7 @@
> #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[] = {
> @@ -220,6 +221,8 @@ 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
> @@ -227,6 +230,7 @@ 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;
> }
>
> @@ -282,6 +286,8 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
> else
> of_device_make_bus_id(&dev->dev);
>
> + of_reserved_mem_device_init(&dev->dev);
> +
> /* Allow the HW Peripheral ID to be overridden */
> prop = of_get_property(node, "arm,primecell-periphid", NULL);
> if (prop)
> @@ -308,6 +314,7 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
> return dev;
>
> err_free:
> + of_reserved_mem_device_release(&dev->dev);
> amba_device_put(dev);
> return NULL;
> }
> diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
> index bc2121fa9132..f10f64fcc815 100644
> --- a/include/asm-generic/vmlinux.lds.h
> +++ b/include/asm-generic/vmlinux.lds.h
> @@ -167,6 +167,16 @@
> #define CLK_OF_TABLES()
> #endif
>
> +#ifdef CONFIG_OF_RESERVED_MEM
> +#define RESERVEDMEM_OF_TABLES() \
> + . = ALIGN(8); \
> + VMLINUX_SYMBOL(__reservedmem_of_table) = .; \
> + *(__reservedmem_of_table) \
> + *(__reservedmem_of_table_end)
> +#else
> +#define RESERVEDMEM_OF_TABLES()
> +#endif
> +
> #define KERNEL_DTB() \
> STRUCT_ALIGN(); \
> VMLINUX_SYMBOL(__dtb_start) = .; \
> @@ -490,6 +500,7 @@
> TRACE_SYSCALLS() \
> MEM_DISCARD(init.rodata) \
> CLK_OF_TABLES() \
> + RESERVEDMEM_OF_TABLES() \
> CLKSRC_OF_TABLES() \
> KERNEL_DTB() \
> IRQCHIP_OF_MATCH_TABLE()
> diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
> new file mode 100644
> index 000000000000..39a4fb17a5ea
> --- /dev/null
> +++ b/include/linux/of_reserved_mem.h
> @@ -0,0 +1,65 @@
> +#ifndef __OF_RESERVED_MEM_H
> +#define __OF_RESERVED_MEM_H
> +
> +struct cma;
> +struct platform_device;
> +struct of_phandle_args;
> +struct reserved_mem_ops;
> +
> +struct reserved_mem {
> + const char *name;
> + struct device_node *node;
> + const struct reserved_mem_ops *ops;
> + phys_addr_t base;
> + phys_addr_t size;
> + void *priv;
> +};
> +
> +struct reserved_mem_ops {
> + void (*device_init)(struct reserved_mem *rmem,
> + struct device *dev,
> + struct of_phandle_args *args);
> + void (*device_release)(struct reserved_mem *rmem,
> + struct device *dev);
> +};
> +
> +typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem,
> + unsigned long node, const char *uname);
> +
> +#ifdef CONFIG_OF_RESERVED_MEM
> +void of_reserved_mem_device_init(struct device *dev);
> +void of_reserved_mem_device_release(struct device *dev);
> +void early_init_dt_scan_reserved_mem(void);
> +void of_reserved_mem_scan(void);
> +
> +int of_parse_flat_dt_reg(unsigned long node, const char *uname,
> + phys_addr_t *base, phys_addr_t *size);
> +int of_parse_flat_dt_size(unsigned long node, const char *uname,
> + phys_addr_t *size);
> +
> +#define RESERVEDMEM_OF_DECLARE(name, compat, init) \
> + static const struct of_device_id __reservedmem_of_table_##name \
> + __used __section(__reservedmem_of_table) \
> + = { .compatible = compat, \
> + .data = (init == (reservedmem_of_init_fn)NULL) ? \
> + init : init }
> +
> +#else
> +static inline void of_reserved_mem_device_init(struct device *dev) { }
> +
> +static inline
> +void of_reserved_mem_device_release(struct device *pdev) { }
> +
> +static inline void early_init_dt_scan_reserved_mem(void) { }
> +static inline void of_reserved_mem_scan(void) { }
> +
> +#define RESERVEDMEM_OF_DECLARE(name, compat, init) \
> + static const struct of_device_id __reservedmem_of_table_##name \
> + __attribute__((unused)) \
> + = { .compatible = compat, \
> + .data = (init == (reservedmem_of_init_fn)NULL) ? \
> + init : init }
> +
> +#endif
> +
> +#endif /* __OF_RESERVED_MEM_H */
> --
> 1.7.9.5
>
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
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