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
diff --git a/arch/arm/include/asm/mach/arch.h b/arch/arm/include/asm/mach/arch.h
index 060a75e..0406cb3 100644
--- a/arch/arm/include/asm/mach/arch.h
+++ b/arch/arm/include/asm/mach/arch.h
@@ -50,6 +50,7 @@
struct smp_operations *smp; /* SMP operations */
bool (*smp_init)(void);
void (*fixup)(struct tag *, char **);
+ void (*dt_fixup)(void);
void (*init_meminfo)(void);
void (*reserve)(void);/* reserve mem blocks */
void (*map_io)(void);/* IO mapping function */
diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index e94a157..11c54de 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -212,7 +212,7 @@
mdesc_best = &__mach_desc_GENERIC_DT;
#endif
- if (!dt_phys || !early_init_dt_scan(phys_to_virt(dt_phys)))
+ if (!dt_phys || !early_init_dt_verify(phys_to_virt(dt_phys)))
return NULL;
mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
@@ -237,6 +237,12 @@
dump_machine_table(); /* does not return */
}
+ /* We really don't want to do this, but sometimes firmware provides buggy data */
+ if (mdesc->dt_fixup)
+ mdesc->dt_fixup();
+
+ early_init_dt_scan_nodes();
+
/* Change machine number to match the mdesc we're using */
__machine_arch_type = mdesc->nr;
diff --git a/arch/arm/mach-exynos/exynos.c b/arch/arm/mach-exynos/exynos.c
index 46d893f..66c9b96 100644
--- a/arch/arm/mach-exynos/exynos.c
+++ b/arch/arm/mach-exynos/exynos.c
@@ -335,6 +335,15 @@
#endif
}
+static void __init exynos_dt_fixup(void)
+{
+ /*
+ * Some versions of uboot pass garbage entries in the memory node,
+ * use the old CONFIG_ARM_NR_BANKS
+ */
+ of_fdt_limit_memory(8);
+}
+
DT_MACHINE_START(EXYNOS_DT, "SAMSUNG EXYNOS (Flattened Device Tree)")
/* Maintainer: Thomas Abraham <thomas.abraham@linaro.org> */
/* Maintainer: Kukjin Kim <kgene.kim@samsung.com> */
@@ -348,4 +357,5 @@
.dt_compat = exynos_dt_compat,
.restart = exynos_restart,
.reserve = exynos_reserve,
+ .dt_fixup = exynos_dt_fixup,
MACHINE_END
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index b777d8f..9aa012e 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -26,6 +26,54 @@
#include <asm/setup.h> /* for COMMAND_LINE_SIZE */
#include <asm/page.h>
+/*
+ * of_fdt_limit_memory - limit the number of regions in the /memory node
+ * @limit: maximum entries
+ *
+ * Adjust the flattened device tree to have at most 'limit' number of
+ * memory entries in the /memory node. This function may be called
+ * any time after initial_boot_param is set.
+ */
+void of_fdt_limit_memory(int limit)
+{
+ int memory;
+ int len;
+ const void *val;
+ int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+ int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+ const uint32_t *addr_prop;
+ const uint32_t *size_prop;
+ int root_offset;
+ int cell_size;
+
+ root_offset = fdt_path_offset(initial_boot_params, "/");
+ if (root_offset < 0)
+ return;
+
+ addr_prop = fdt_getprop(initial_boot_params, root_offset,
+ "#address-cells", NULL);
+ if (addr_prop)
+ nr_address_cells = fdt32_to_cpu(*addr_prop);
+
+ size_prop = fdt_getprop(initial_boot_params, root_offset,
+ "#size-cells", NULL);
+ if (size_prop)
+ nr_size_cells = fdt32_to_cpu(*size_prop);
+
+ cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
+
+ memory = fdt_path_offset(initial_boot_params, "/memory");
+ if (memory > 0) {
+ val = fdt_getprop(initial_boot_params, memory, "reg", &len);
+ if (len > limit*cell_size) {
+ len = limit*cell_size;
+ pr_debug("Limiting number of entries to %d\n", limit);
+ fdt_setprop(initial_boot_params, memory, "reg", val,
+ len);
+ }
+ }
+}
+
/**
* of_fdt_is_compatible - Return true if given node from the given blob has
* compat in its compatible list
@@ -937,7 +985,7 @@
}
#endif
-bool __init early_init_dt_scan(void *params)
+bool __init early_init_dt_verify(void *params)
{
if (!params)
return false;
@@ -951,6 +999,12 @@
return false;
}
+ return true;
+}
+
+
+void __init early_init_dt_scan_nodes(void)
+{
/* Retrieve various information from the /chosen node */
of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
@@ -959,7 +1013,17 @@
/* Setup memory, calling early_init_dt_add_memory_arch */
of_scan_flat_dt(early_init_dt_scan_memory, NULL);
+}
+bool __init early_init_dt_scan(void *params)
+{
+ bool status;
+
+ status = early_init_dt_verify(params);
+ if (!status)
+ return false;
+
+ early_init_dt_scan_nodes();
return true;
}
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index 0511789..0ff360d 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -73,6 +73,8 @@
int depth, void *data);
extern bool early_init_dt_scan(void *params);
+extern bool early_init_dt_verify(void *params);
+extern void early_init_dt_scan_nodes(void);
extern const char *of_flat_dt_get_machine_name(void);
extern const void *of_flat_dt_match_machine(const void *default_match,
@@ -84,6 +86,7 @@
extern void early_init_devtree(void *);
extern void early_get_first_memblock_info(void *, phys_addr_t *);
extern u64 fdt_translate_address(const void *blob, int node_offset);
+extern void of_fdt_limit_memory(int limit);
#else /* CONFIG_OF_FLATTREE */
static inline void early_init_fdt_scan_reserved_mem(void) {}
static inline const char *of_flat_dt_get_machine_name(void) { return NULL; }