Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux
Pull Exynos platform DT fix from Grant Likely:
"Device tree Exynos bug fix for v3.16-rc7
This bug fix has been brewing for a while. I hate sending it to you
so late, but I only got confirmation that it solves the problem this
past weekend. The diff looks big for a bug fix, but the majority of
it is only executed in the Exynos quirk case. Unfortunately it
required splitting early_init_dt_scan() in two and adding quirk
handling in the middle of it on ARM.
Exynos has buggy firmware that puts bad data into the memory node.
Commit 1c2f87c22566 ("ARM: Get rid of meminfo") exposed the bug by
dropping the artificial upper bound on the number of memory banks that
can be added. Exynos fails to boot after that commit. This branch
fixes it by splitting the early DT parse function and inserting a
fixup hook. Exynos uses the hook to correct the DT before parsing
memory regions"
* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux:
arm: Add devicetree fixup machine function
of: Add memory limiting function for flattened devicetrees
of: Split early_init_dt_scan into two parts
+86
-2
+1
arch/arm/include/asm/mach/arch.h
+1
arch/arm/include/asm/mach/arch.h
···
50
50
struct smp_operations *smp; /* SMP operations */
51
51
bool (*smp_init)(void);
52
52
void (*fixup)(struct tag *, char **);
53
+
void (*dt_fixup)(void);
53
54
void (*init_meminfo)(void);
54
55
void (*reserve)(void);/* reserve mem blocks */
55
56
void (*map_io)(void);/* IO mapping function */
+7
-1
arch/arm/kernel/devtree.c
+7
-1
arch/arm/kernel/devtree.c
···
212
212
mdesc_best = &__mach_desc_GENERIC_DT;
213
213
#endif
214
214
215
-
if (!dt_phys || !early_init_dt_scan(phys_to_virt(dt_phys)))
215
+
if (!dt_phys || !early_init_dt_verify(phys_to_virt(dt_phys)))
216
216
return NULL;
217
217
218
218
mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
···
236
236
237
237
dump_machine_table(); /* does not return */
238
238
}
239
+
240
+
/* We really don't want to do this, but sometimes firmware provides buggy data */
241
+
if (mdesc->dt_fixup)
242
+
mdesc->dt_fixup();
243
+
244
+
early_init_dt_scan_nodes();
239
245
240
246
/* Change machine number to match the mdesc we're using */
241
247
__machine_arch_type = mdesc->nr;
+10
arch/arm/mach-exynos/exynos.c
+10
arch/arm/mach-exynos/exynos.c
···
335
335
#endif
336
336
}
337
337
338
+
static void __init exynos_dt_fixup(void)
339
+
{
340
+
/*
341
+
* Some versions of uboot pass garbage entries in the memory node,
342
+
* use the old CONFIG_ARM_NR_BANKS
343
+
*/
344
+
of_fdt_limit_memory(8);
345
+
}
346
+
338
347
DT_MACHINE_START(EXYNOS_DT, "SAMSUNG EXYNOS (Flattened Device Tree)")
339
348
/* Maintainer: Thomas Abraham <thomas.abraham@linaro.org> */
340
349
/* Maintainer: Kukjin Kim <kgene.kim@samsung.com> */
···
357
348
.dt_compat = exynos_dt_compat,
358
349
.restart = exynos_restart,
359
350
.reserve = exynos_reserve,
351
+
.dt_fixup = exynos_dt_fixup,
360
352
MACHINE_END
+65
-1
drivers/of/fdt.c
+65
-1
drivers/of/fdt.c
···
26
26
#include <asm/setup.h> /* for COMMAND_LINE_SIZE */
27
27
#include <asm/page.h>
28
28
29
+
/*
30
+
* of_fdt_limit_memory - limit the number of regions in the /memory node
31
+
* @limit: maximum entries
32
+
*
33
+
* Adjust the flattened device tree to have at most 'limit' number of
34
+
* memory entries in the /memory node. This function may be called
35
+
* any time after initial_boot_param is set.
36
+
*/
37
+
void of_fdt_limit_memory(int limit)
38
+
{
39
+
int memory;
40
+
int len;
41
+
const void *val;
42
+
int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
43
+
int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
44
+
const uint32_t *addr_prop;
45
+
const uint32_t *size_prop;
46
+
int root_offset;
47
+
int cell_size;
48
+
49
+
root_offset = fdt_path_offset(initial_boot_params, "/");
50
+
if (root_offset < 0)
51
+
return;
52
+
53
+
addr_prop = fdt_getprop(initial_boot_params, root_offset,
54
+
"#address-cells", NULL);
55
+
if (addr_prop)
56
+
nr_address_cells = fdt32_to_cpu(*addr_prop);
57
+
58
+
size_prop = fdt_getprop(initial_boot_params, root_offset,
59
+
"#size-cells", NULL);
60
+
if (size_prop)
61
+
nr_size_cells = fdt32_to_cpu(*size_prop);
62
+
63
+
cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
64
+
65
+
memory = fdt_path_offset(initial_boot_params, "/memory");
66
+
if (memory > 0) {
67
+
val = fdt_getprop(initial_boot_params, memory, "reg", &len);
68
+
if (len > limit*cell_size) {
69
+
len = limit*cell_size;
70
+
pr_debug("Limiting number of entries to %d\n", limit);
71
+
fdt_setprop(initial_boot_params, memory, "reg", val,
72
+
len);
73
+
}
74
+
}
75
+
}
76
+
29
77
/**
30
78
* of_fdt_is_compatible - Return true if given node from the given blob has
31
79
* compat in its compatible list
···
985
937
}
986
938
#endif
987
939
988
-
bool __init early_init_dt_scan(void *params)
940
+
bool __init early_init_dt_verify(void *params)
989
941
{
990
942
if (!params)
991
943
return false;
···
999
951
return false;
1000
952
}
1001
953
954
+
return true;
955
+
}
956
+
957
+
958
+
void __init early_init_dt_scan_nodes(void)
959
+
{
1002
960
/* Retrieve various information from the /chosen node */
1003
961
of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1004
962
···
1013
959
1014
960
/* Setup memory, calling early_init_dt_add_memory_arch */
1015
961
of_scan_flat_dt(early_init_dt_scan_memory, NULL);
962
+
}
1016
963
964
+
bool __init early_init_dt_scan(void *params)
965
+
{
966
+
bool status;
967
+
968
+
status = early_init_dt_verify(params);
969
+
if (!status)
970
+
return false;
971
+
972
+
early_init_dt_scan_nodes();
1017
973
return true;
1018
974
}
1019
975
+3
include/linux/of_fdt.h
+3
include/linux/of_fdt.h
···
73
73
int depth, void *data);
74
74
75
75
extern bool early_init_dt_scan(void *params);
76
+
extern bool early_init_dt_verify(void *params);
77
+
extern void early_init_dt_scan_nodes(void);
76
78
77
79
extern const char *of_flat_dt_get_machine_name(void);
78
80
extern const void *of_flat_dt_match_machine(const void *default_match,
···
86
84
extern void early_init_devtree(void *);
87
85
extern void early_get_first_memblock_info(void *, phys_addr_t *);
88
86
extern u64 fdt_translate_address(const void *blob, int node_offset);
87
+
extern void of_fdt_limit_memory(int limit);
89
88
#else /* CONFIG_OF_FLATTREE */
90
89
static inline void early_init_fdt_scan_reserved_mem(void) {}
91
90
static inline const char *of_flat_dt_get_machine_name(void) { return NULL; }