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drivers: of: add initialization code for dynamic reserved memory
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> Signed-off-by: Grant Likely <grant.likely@linaro.org>
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‎drivers/of/Kconfig

Lines changed: 6 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -79,4 +79,10 @@ config OF_MTD
7979
depends on MTD
8080
def_bool y
8181

82+
config OF_RESERVED_MEM
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depends on OF_EARLY_FLATTREE
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bool
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help
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Helpers to allow for reservation of memory regions
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8288
endmenu # OF

‎drivers/of/Makefile

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -9,3 +9,4 @@ obj-$(CONFIG_OF_MDIO) += of_mdio.o
99
obj-$(CONFIG_OF_PCI) += of_pci.o
1010
obj-$(CONFIG_OF_PCI_IRQ) += of_pci_irq.o
1111
obj-$(CONFIG_OF_MTD) += of_mtd.o
12+
obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o

‎drivers/of/fdt.c

Lines changed: 11 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -15,6 +15,7 @@
1515
#include <linux/module.h>
1616
#include <linux/of.h>
1717
#include <linux/of_fdt.h>
18+
#include <linux/of_reserved_mem.h>
1819
#include <linux/sizes.h>
1920
#include <linux/string.h>
2021
#include <linux/errno.h>
@@ -450,7 +451,7 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
450451
phys_addr_t base, size;
451452
unsigned long len;
452453
__be32 *prop;
453-
int nomap;
454+
int nomap, first = 1;
454455

455456
prop = of_get_flat_dt_prop(node, "reg", &len);
456457
if (!prop)
@@ -477,6 +478,10 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
477478
uname, &base, (unsigned long)size / SZ_1M);
478479

479480
len -= t_len;
481+
if (first) {
482+
fdt_reserved_mem_save_node(node, uname, base, size);
483+
first = 0;
484+
}
480485
}
481486
return 0;
482487
}
@@ -512,6 +517,7 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
512517
{
513518
static int found;
514519
const char *status;
520+
int err;
515521

516522
if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
517523
if (__reserved_mem_check_root(node) != 0) {
@@ -534,7 +540,9 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
534540
if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
535541
return 0;
536542

537-
__reserved_mem_reserve_reg(node, uname);
543+
err = __reserved_mem_reserve_reg(node, uname);
544+
if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
545+
fdt_reserved_mem_save_node(node, uname, 0, 0);
538546

539547
/* scan next node */
540548
return 0;
@@ -550,6 +558,7 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
550558
void __init early_init_fdt_scan_reserved_mem(void)
551559
{
552560
of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
561+
fdt_init_reserved_mem();
553562
}
554563

555564
/**

‎drivers/of/of_reserved_mem.c

Lines changed: 188 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,188 @@
1+
/*
2+
* Device tree based initialization code for reserved memory.
3+
*
4+
* Copyright (c) 2013, The Linux Foundation. All Rights Reserved.
5+
* Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
6+
* http://www.samsung.com
7+
* Author: Marek Szyprowski <m.szyprowski@samsung.com>
8+
* Author: Josh Cartwright <joshc@codeaurora.org>
9+
*
10+
* This program is free software; you can redistribute it and/or
11+
* modify it under the terms of the GNU General Public License as
12+
* published by the Free Software Foundation; either version 2 of the
13+
* License or (at your optional) any later version of the license.
14+
*/
15+
16+
#include <linux/err.h>
17+
#include <linux/of.h>
18+
#include <linux/of_fdt.h>
19+
#include <linux/of_platform.h>
20+
#include <linux/mm.h>
21+
#include <linux/sizes.h>
22+
#include <linux/of_reserved_mem.h>
23+
24+
#define MAX_RESERVED_REGIONS 16
25+
static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
26+
static int reserved_mem_count;
27+
28+
#if defined(CONFIG_HAVE_MEMBLOCK)
29+
#include <linux/memblock.h>
30+
int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
31+
phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
32+
phys_addr_t *res_base)
33+
{
34+
/*
35+
* We use __memblock_alloc_base() because memblock_alloc_base()
36+
* panic()s on allocation failure.
37+
*/
38+
phys_addr_t base = __memblock_alloc_base(size, align, end);
39+
if (!base)
40+
return -ENOMEM;
41+
42+
/*
43+
* Check if the allocated region fits in to start..end window
44+
*/
45+
if (base < start) {
46+
memblock_free(base, size);
47+
return -ENOMEM;
48+
}
49+
50+
*res_base = base;
51+
if (nomap)
52+
return memblock_remove(base, size);
53+
return 0;
54+
}
55+
#else
56+
int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
57+
phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
58+
phys_addr_t *res_base)
59+
{
60+
pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
61+
size, nomap ? " (nomap)" : "");
62+
return -ENOSYS;
63+
}
64+
#endif
65+
66+
/**
67+
* res_mem_save_node() - save fdt node for second pass initialization
68+
*/
69+
void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
70+
phys_addr_t base, phys_addr_t size)
71+
{
72+
struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
73+
74+
if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
75+
pr_err("Reserved memory: not enough space all defined regions.\n");
76+
return;
77+
}
78+
79+
rmem->fdt_node = node;
80+
rmem->name = uname;
81+
rmem->base = base;
82+
rmem->size = size;
83+
84+
reserved_mem_count++;
85+
return;
86+
}
87+
88+
/**
89+
* res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
90+
* and 'alloc-ranges' properties
91+
*/
92+
static int __init __reserved_mem_alloc_size(unsigned long node,
93+
const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
94+
{
95+
int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
96+
phys_addr_t start = 0, end = 0;
97+
phys_addr_t base = 0, align = 0, size;
98+
unsigned long len;
99+
__be32 *prop;
100+
int nomap;
101+
int ret;
102+
103+
prop = of_get_flat_dt_prop(node, "size", &len);
104+
if (!prop)
105+
return -EINVAL;
106+
107+
if (len != dt_root_size_cells * sizeof(__be32)) {
108+
pr_err("Reserved memory: invalid size property in '%s' node.\n",
109+
uname);
110+
return -EINVAL;
111+
}
112+
size = dt_mem_next_cell(dt_root_size_cells, &prop);
113+
114+
nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
115+
116+
prop = of_get_flat_dt_prop(node, "alignment", &len);
117+
if (prop) {
118+
if (len != dt_root_addr_cells * sizeof(__be32)) {
119+
pr_err("Reserved memory: invalid alignment property in '%s' node.\n",
120+
uname);
121+
return -EINVAL;
122+
}
123+
align = dt_mem_next_cell(dt_root_addr_cells, &prop);
124+
}
125+
126+
prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
127+
if (prop) {
128+
129+
if (len % t_len != 0) {
130+
pr_err("Reserved memory: invalid alloc-ranges property in '%s', skipping node.\n",
131+
uname);
132+
return -EINVAL;
133+
}
134+
135+
base = 0;
136+
137+
while (len > 0) {
138+
start = dt_mem_next_cell(dt_root_addr_cells, &prop);
139+
end = start + dt_mem_next_cell(dt_root_size_cells,
140+
&prop);
141+
142+
ret = early_init_dt_alloc_reserved_memory_arch(size,
143+
align, start, end, nomap, &base);
144+
if (ret == 0) {
145+
pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
146+
uname, &base,
147+
(unsigned long)size / SZ_1M);
148+
break;
149+
}
150+
len -= t_len;
151+
}
152+
153+
} else {
154+
ret = early_init_dt_alloc_reserved_memory_arch(size, align,
155+
0, 0, nomap, &base);
156+
if (ret == 0)
157+
pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
158+
uname, &base, (unsigned long)size / SZ_1M);
159+
}
160+
161+
if (base == 0) {
162+
pr_info("Reserved memory: failed to allocate memory for node '%s'\n",
163+
uname);
164+
return -ENOMEM;
165+
}
166+
167+
*res_base = base;
168+
*res_size = size;
169+
170+
return 0;
171+
}
172+
173+
/**
174+
* fdt_init_reserved_mem - allocate and init all saved reserved memory regions
175+
*/
176+
void __init fdt_init_reserved_mem(void)
177+
{
178+
int i;
179+
for (i = 0; i < reserved_mem_count; i++) {
180+
struct reserved_mem *rmem = &reserved_mem[i];
181+
unsigned long node = rmem->fdt_node;
182+
int err = 0;
183+
184+
if (rmem->size == 0)
185+
err = __reserved_mem_alloc_size(node, rmem->name,
186+
&rmem->base, &rmem->size);
187+
}
188+
}

‎include/linux/of_reserved_mem.h

Lines changed: 21 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,21 @@
1+
#ifndef __OF_RESERVED_MEM_H
2+
#define __OF_RESERVED_MEM_H
3+
4+
struct reserved_mem {
5+
const char *name;
6+
unsigned long fdt_node;
7+
phys_addr_t base;
8+
phys_addr_t size;
9+
};
10+
11+
#ifdef CONFIG_OF_RESERVED_MEM
12+
void fdt_init_reserved_mem(void);
13+
void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
14+
phys_addr_t base, phys_addr_t size);
15+
#else
16+
static inline void fdt_init_reserved_mem(void) { }
17+
static inline void fdt_reserved_mem_save_node(unsigned long node,
18+
const char *uname, phys_addr_t base, phys_addr_t size) { }
19+
#endif
20+
21+
#endif /* __OF_RESERVED_MEM_H */

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