linux/drivers/of/of_reserved_mem.c
Michael Ellerman 9eb8cd2b07 of: Fix comparison of reserved memory regions
In order to check for overlapping reserved memory regions, we first need
to sort the array of memory regions. This is implemented using sort(),
and a custom comparison function __rmem_cmp().

Unfortunatley __rmem_cmp() doesn't work in all cases. Because the two
base values are phys_addr_t, they may be u64 on some platforms, in which
case subtracting one from the other and then (implicitly) casting to int
does not give us the -ve/0/+ve value we need.

This leads to incorrect reports about overlaps, eg:

  ibm,slw-image@1ffe600000 (0x0000001ffe600000--0x0000001ffe700000) overlaps with
  ibm,firmware-allocs-memory@1000000000 (0x0000001000000000--0x0000001000dc0200)

Fix it by just doing the standard double if and return 0 logic.

Fixes: ae1add247b ("of: Check for overlap in reserved memory regions")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Rob Herring <robh@kernel.org>
2015-11-30 17:56:44 -06:00

344 lines
8.7 KiB
C

/*
* 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>
*
* 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>
#include <linux/sort.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_err("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;
int len;
const __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);
}
/* Need adjust the alignment to satisfy the CMA requirement */
if (IS_ENABLED(CONFIG_CMA) && of_flat_dt_is_compatible(node, "shared-dma-pool"))
align = max(align, (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order));
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 __reserved_mem_init_node(struct reserved_mem *rmem)
{
extern const struct of_device_id __reservedmem_of_table[];
const struct of_device_id *i;
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;
if (initfn(rmem) == 0) {
pr_info("Reserved memory: initialized node %s, compatible id %s\n",
rmem->name, compat);
return 0;
}
}
return -ENOENT;
}
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;
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 && next->base))
continue;
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("Reserved memory: 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;
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)
__reserved_mem_init_node(rmem);
}
}
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;
}
/**
* 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.
*/
int of_reserved_mem_device_init(struct device *dev)
{
struct reserved_mem *rmem;
struct device_node *np;
int ret;
np = of_parse_phandle(dev->of_node, "memory-region", 0);
if (!np)
return -ENODEV;
rmem = __find_rmem(np);
of_node_put(np);
if (!rmem || !rmem->ops || !rmem->ops->device_init)
return -EINVAL;
ret = rmem->ops->device_init(rmem, dev);
if (ret == 0)
dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
return ret;
}
EXPORT_SYMBOL_GPL(of_reserved_mem_device_init);
/**
* 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 *rmem;
struct device_node *np;
np = of_parse_phandle(dev->of_node, "memory-region", 0);
if (!np)
return;
rmem = __find_rmem(np);
of_node_put(np);
if (!rmem || !rmem->ops || !rmem->ops->device_release)
return;
rmem->ops->device_release(rmem, dev);
}
EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);