1212#define pr_fmt (fmt ) "OF: reserved mem: " fmt
1313
1414#include <linux/err.h>
15+ #include <linux/libfdt.h>
1516#include <linux/of.h>
1617#include <linux/of_fdt.h>
1718#include <linux/of_platform.h>
@@ -58,8 +59,8 @@ static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
5859/*
5960 * fdt_reserved_mem_save_node() - save fdt node for second pass initialization
6061 */
61- void __init fdt_reserved_mem_save_node (unsigned long node , const char * uname ,
62- phys_addr_t base , phys_addr_t size )
62+ static void __init fdt_reserved_mem_save_node (unsigned long node , const char * uname ,
63+ phys_addr_t base , phys_addr_t size )
6364{
6465 struct reserved_mem * rmem = & reserved_mem [reserved_mem_count ];
6566
@@ -77,6 +78,126 @@ void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
7778 return ;
7879}
7980
81+ static int __init early_init_dt_reserve_memory (phys_addr_t base ,
82+ phys_addr_t size , bool nomap )
83+ {
84+ if (nomap ) {
85+ /*
86+ * If the memory is already reserved (by another region), we
87+ * should not allow it to be marked nomap, but don't worry
88+ * if the region isn't memory as it won't be mapped.
89+ */
90+ if (memblock_overlaps_region (& memblock .memory , base , size ) &&
91+ memblock_is_region_reserved (base , size ))
92+ return - EBUSY ;
93+
94+ return memblock_mark_nomap (base , size );
95+ }
96+ return memblock_reserve (base , size );
97+ }
98+
99+ /*
100+ * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
101+ */
102+ static int __init __reserved_mem_reserve_reg (unsigned long node ,
103+ const char * uname )
104+ {
105+ int t_len = (dt_root_addr_cells + dt_root_size_cells ) * sizeof (__be32 );
106+ phys_addr_t base , size ;
107+ int len ;
108+ const __be32 * prop ;
109+ int first = 1 ;
110+ bool nomap ;
111+
112+ prop = of_get_flat_dt_prop (node , "reg" , & len );
113+ if (!prop )
114+ return - ENOENT ;
115+
116+ if (len && len % t_len != 0 ) {
117+ pr_err ("Reserved memory: invalid reg property in '%s', skipping node.\n" ,
118+ uname );
119+ return - EINVAL ;
120+ }
121+
122+ nomap = of_get_flat_dt_prop (node , "no-map" , NULL ) != NULL ;
123+
124+ while (len >= t_len ) {
125+ base = dt_mem_next_cell (dt_root_addr_cells , & prop );
126+ size = dt_mem_next_cell (dt_root_size_cells , & prop );
127+
128+ if (size &&
129+ early_init_dt_reserve_memory (base , size , nomap ) == 0 )
130+ pr_debug ("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n" ,
131+ uname , & base , (unsigned long )(size / SZ_1M ));
132+ else
133+ pr_err ("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n" ,
134+ uname , & base , (unsigned long )(size / SZ_1M ));
135+
136+ len -= t_len ;
137+ if (first ) {
138+ fdt_reserved_mem_save_node (node , uname , base , size );
139+ first = 0 ;
140+ }
141+ }
142+ return 0 ;
143+ }
144+
145+ /*
146+ * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
147+ * in /reserved-memory matches the values supported by the current implementation,
148+ * also check if ranges property has been provided
149+ */
150+ static int __init __reserved_mem_check_root (unsigned long node )
151+ {
152+ const __be32 * prop ;
153+
154+ prop = of_get_flat_dt_prop (node , "#size-cells" , NULL );
155+ if (!prop || be32_to_cpup (prop ) != dt_root_size_cells )
156+ return - EINVAL ;
157+
158+ prop = of_get_flat_dt_prop (node , "#address-cells" , NULL );
159+ if (!prop || be32_to_cpup (prop ) != dt_root_addr_cells )
160+ return - EINVAL ;
161+
162+ prop = of_get_flat_dt_prop (node , "ranges" , NULL );
163+ if (!prop )
164+ return - EINVAL ;
165+ return 0 ;
166+ }
167+
168+ /*
169+ * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
170+ */
171+ int __init fdt_scan_reserved_mem (void )
172+ {
173+ int node , child ;
174+ const void * fdt = initial_boot_params ;
175+
176+ node = fdt_path_offset (fdt , "/reserved-memory" );
177+ if (node < 0 )
178+ return - ENODEV ;
179+
180+ if (__reserved_mem_check_root (node ) != 0 ) {
181+ pr_err ("Reserved memory: unsupported node format, ignoring\n" );
182+ return - EINVAL ;
183+ }
184+
185+ fdt_for_each_subnode (child , fdt , node ) {
186+ const char * uname ;
187+ int err ;
188+
189+ if (!of_fdt_device_is_available (fdt , child ))
190+ continue ;
191+
192+ uname = fdt_get_name (fdt , child , NULL );
193+
194+ err = __reserved_mem_reserve_reg (child , uname );
195+ if (err == - ENOENT && of_get_flat_dt_prop (child , "size" , NULL ))
196+ fdt_reserved_mem_save_node (child , uname , 0 , 0 );
197+ }
198+ return 0 ;
199+ }
200+
80201/*
81202 * __reserved_mem_alloc_in_range() - allocate reserved memory described with
82203 * 'alloc-ranges'. Choose bottom-up/top-down depending on nearby existing
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