linux/drivers/of/of_reserved_mem.c
Vincent Whitchurch ca05f33316 of: Fix reserved-memory overlap detection
The reserved-memory overlap detection code fails to detect overlaps if
either of the regions starts at address 0x0.  The code explicitly checks
for and ignores such regions, apparently in order to ignore dynamically
allocated regions which have an address of 0x0 at this point.  These
dynamically allocated regions also have a size of 0x0 at this point, so
fix this by removing the check and sorting the dynamically allocated
regions ahead of any static regions at address 0x0.

For example, there are two overlaps in this case but they are not
currently reported:

	foo@0 {
	        reg = <0x0 0x2000>;
	};

	bar@0 {
	        reg = <0x0 0x1000>;
	};

	baz@1000 {
	        reg = <0x1000 0x1000>;
	};

	quux {
	        size = <0x1000>;
	};

but they are after this patch:

 OF: reserved mem: OVERLAP DETECTED!
 bar@0 (0x00000000--0x00001000) overlaps with foo@0 (0x00000000--0x00002000)
 OF: reserved mem: OVERLAP DETECTED!
 foo@0 (0x00000000--0x00002000) overlaps with baz@1000 (0x00001000--0x00002000)

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/ded6fd6b47b58741aabdcc6967f73eca6a3f311e.1603273666.git-series.vincent.whitchurch@axis.com
Signed-off-by: Rob Herring <robh@kernel.org>
2020-10-25 20:37:55 -05:00

441 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Device tree based initialization code for reserved memory.
*
* Copyright (c) 2013, 2015 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>
*/
#define pr_fmt(fmt) "OF: reserved mem: " fmt
#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>
#include <linux/sort.h>
#include <linux/slab.h>
#include <linux/memblock.h>
#define MAX_RESERVED_REGIONS 64
static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
static int reserved_mem_count;
static int __init 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)
{
phys_addr_t base;
end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
align = !align ? SMP_CACHE_BYTES : align;
base = memblock_find_in_range(start, end, size, align);
if (!base)
return -ENOMEM;
*res_base = base;
if (nomap)
return memblock_remove(base, size);
return memblock_reserve(base, size);
}
/**
* fdt_reserved_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("not enough space for all defined regions.\n");
return;
}
rmem->fdt_node = node;
rmem->name = uname;
rmem->base = base;
rmem->size = size;
reserved_mem_count++;
return;
}
/**
* __reserved_mem_alloc_size() - allocate reserved memory described by
* 'size', 'alignment' 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;
int len;
const __be32 *prop;
bool 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("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, "alignment", &len);
if (prop) {
if (len != dt_root_addr_cells * sizeof(__be32)) {
pr_err("invalid alignment property in '%s' node.\n",
uname);
return -EINVAL;
}
align = dt_mem_next_cell(dt_root_addr_cells, &prop);
}
nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
/* Need adjust the alignment to satisfy the CMA requirement */
if (IS_ENABLED(CONFIG_CMA)
&& of_flat_dt_is_compatible(node, "shared-dma-pool")
&& of_get_flat_dt_prop(node, "reusable", NULL)
&& !nomap) {
unsigned long order =
max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
align = max(align, (phys_addr_t)PAGE_SIZE << order);
}
prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
if (prop) {
if (len % t_len != 0) {
pr_err("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("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("allocated memory for '%s' node: base %pa, size %ld MiB\n",
uname, &base, (unsigned long)size / SZ_1M);
}
if (base == 0) {
pr_info("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");
/**
* __reserved_mem_init_node() - call region specific reserved memory init code
*/
static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
{
extern const struct of_device_id __reservedmem_of_table[];
const struct of_device_id *i;
int ret = -ENOENT;
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(rmem->fdt_node, compat))
continue;
ret = initfn(rmem);
if (ret == 0) {
pr_info("initialized node %s, compatible id %s\n",
rmem->name, compat);
break;
}
}
return ret;
}
static int __init __rmem_cmp(const void *a, const void *b)
{
const struct reserved_mem *ra = a, *rb = b;
if (ra->base < rb->base)
return -1;
if (ra->base > rb->base)
return 1;
/*
* Put the dynamic allocations (address == 0, size == 0) before static
* allocations at address 0x0 so that overlap detection works
* correctly.
*/
if (ra->size < rb->size)
return -1;
if (ra->size > rb->size)
return 1;
return 0;
}
static void __init __rmem_check_for_overlap(void)
{
int i;
if (reserved_mem_count < 2)
return;
sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
__rmem_cmp, NULL);
for (i = 0; i < reserved_mem_count - 1; i++) {
struct reserved_mem *this, *next;
this = &reserved_mem[i];
next = &reserved_mem[i + 1];
if (this->base + this->size > next->base) {
phys_addr_t this_end, next_end;
this_end = this->base + this->size;
next_end = next->base + next->size;
pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
this->name, &this->base, &this_end,
next->name, &next->base, &next_end);
}
}
}
/**
* fdt_init_reserved_mem() - allocate and init all saved reserved memory regions
*/
void __init fdt_init_reserved_mem(void)
{
int i;
/* check for overlapping reserved regions */
__rmem_check_for_overlap();
for (i = 0; i < reserved_mem_count; i++) {
struct reserved_mem *rmem = &reserved_mem[i];
unsigned long node = rmem->fdt_node;
int len;
const __be32 *prop;
int err = 0;
bool nomap;
nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
prop = of_get_flat_dt_prop(node, "phandle", &len);
if (!prop)
prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
if (prop)
rmem->phandle = of_read_number(prop, len/4);
if (rmem->size == 0)
err = __reserved_mem_alloc_size(node, rmem->name,
&rmem->base, &rmem->size);
if (err == 0) {
err = __reserved_mem_init_node(rmem);
if (err != 0 && err != -ENOENT) {
pr_info("node %s compatible matching fail\n",
rmem->name);
memblock_free(rmem->base, rmem->size);
if (nomap)
memblock_add(rmem->base, rmem->size);
}
}
}
}
static inline struct reserved_mem *__find_rmem(struct device_node *node)
{
unsigned int i;
if (!node->phandle)
return NULL;
for (i = 0; i < reserved_mem_count; i++)
if (reserved_mem[i].phandle == node->phandle)
return &reserved_mem[i];
return NULL;
}
struct rmem_assigned_device {
struct device *dev;
struct reserved_mem *rmem;
struct list_head list;
};
static LIST_HEAD(of_rmem_assigned_device_list);
static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
/**
* of_reserved_mem_device_init_by_idx() - assign reserved memory region to
* given device
* @dev: Pointer to the device to configure
* @np: Pointer to the device_node with 'reserved-memory' property
* @idx: Index of selected region
*
* This function assigns respective DMA-mapping operations based on reserved
* memory region specified by 'memory-region' property in @np node to the @dev
* device. When driver needs to use more than one reserved memory region, it
* should allocate child devices and initialize regions by name for each of
* child device.
*
* Returns error code or zero on success.
*/
int of_reserved_mem_device_init_by_idx(struct device *dev,
struct device_node *np, int idx)
{
struct rmem_assigned_device *rd;
struct device_node *target;
struct reserved_mem *rmem;
int ret;
if (!np || !dev)
return -EINVAL;
target = of_parse_phandle(np, "memory-region", idx);
if (!target)
return -ENODEV;
if (!of_device_is_available(target)) {
of_node_put(target);
return 0;
}
rmem = __find_rmem(target);
of_node_put(target);
if (!rmem || !rmem->ops || !rmem->ops->device_init)
return -EINVAL;
rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
if (!rd)
return -ENOMEM;
ret = rmem->ops->device_init(rmem, dev);
if (ret == 0) {
rd->dev = dev;
rd->rmem = rmem;
mutex_lock(&of_rmem_assigned_device_mutex);
list_add(&rd->list, &of_rmem_assigned_device_list);
mutex_unlock(&of_rmem_assigned_device_mutex);
dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
} else {
kfree(rd);
}
return ret;
}
EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
/**
* of_reserved_mem_device_init_by_name() - assign named reserved memory region
* to given device
* @dev: pointer to the device to configure
* @np: pointer to the device node with 'memory-region' property
* @name: name of the selected memory region
*
* Returns: 0 on success or a negative error-code on failure.
*/
int of_reserved_mem_device_init_by_name(struct device *dev,
struct device_node *np,
const char *name)
{
int idx = of_property_match_string(np, "memory-region-names", name);
return of_reserved_mem_device_init_by_idx(dev, np, idx);
}
EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
/**
* of_reserved_mem_device_release() - release reserved memory device structures
* @dev: Pointer to the device to deconfigure
*
* This function releases structures allocated for memory region handling for
* the given device.
*/
void of_reserved_mem_device_release(struct device *dev)
{
struct rmem_assigned_device *rd, *tmp;
LIST_HEAD(release_list);
mutex_lock(&of_rmem_assigned_device_mutex);
list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
if (rd->dev == dev)
list_move_tail(&rd->list, &release_list);
}
mutex_unlock(&of_rmem_assigned_device_mutex);
list_for_each_entry_safe(rd, tmp, &release_list, list) {
if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
rd->rmem->ops->device_release(rd->rmem, dev);
kfree(rd);
}
}
EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
/**
* of_reserved_mem_lookup() - acquire reserved_mem from a device node
* @np: node pointer of the desired reserved-memory region
*
* This function allows drivers to acquire a reference to the reserved_mem
* struct based on a device node handle.
*
* Returns a reserved_mem reference, or NULL on error.
*/
struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
{
const char *name;
int i;
if (!np->full_name)
return NULL;
name = kbasename(np->full_name);
for (i = 0; i < reserved_mem_count; i++)
if (!strcmp(reserved_mem[i].name, name))
return &reserved_mem[i];
return NULL;
}
EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);