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authorLaura Abbott <lauraa@codeaurora.org>2014-07-15 10:03:36 -0700
committerGrant Likely <grant.likely@linaro.org>2014-07-29 21:26:49 -0600
commit5a12a597a8627b91fd9d94365853f9f69a4f399c (patch)
tree3e8b3381fba66b9119bd491d3f3a7fe8401df61f
parent704033cee2e5b3c1c6eaf5bb398e465a9c3667b5 (diff)
downloadlinux-5a12a597a8627b91fd9d94365853f9f69a4f399c.tar.gz
arm: Add devicetree fixup machine function
Commit 1c2f87c22566cd057bc8cde10c37ae9da1a1bb76 (ARM: 8025/1: Get rid of meminfo) dropped the upper bound on the number of memory banks that can be added as there was no technical need in the kernel. It turns out though, some bootloaders (specifically the arndale-octa exynos boards) may pass invalid memory information and rely on the kernel to not parse this data. This is a bug in the bootloader but we still need to work around this. Work around this by introducing a dt_fixup function. This function gets called before the flattened devicetree is scanned for memory and the like. In this fixup function for exynos, limit the maximum number of memory regions in the devicetree. Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Tested-by: Andreas Färber <afaerber@suse.de> [glikely: Added a comment and fixed up function name] Signed-off-by: Grant Likely <grant.likely@linaro.org>
-rw-r--r--arch/arm/include/asm/mach/arch.h1
-rw-r--r--arch/arm/kernel/devtree.c8
-rw-r--r--arch/arm/mach-exynos/exynos.c10
3 files changed, 18 insertions, 1 deletions
diff --git a/arch/arm/include/asm/mach/arch.h b/arch/arm/include/asm/mach/arch.h
index 060a75e9926..0406cb3f1af 100644
--- a/arch/arm/include/asm/mach/arch.h
+++ b/arch/arm/include/asm/mach/arch.h
@@ -50,6 +50,7 @@ struct machine_desc {
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 e94a157ddff..11c54de9f8c 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -212,7 +212,7 @@ const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
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 @@ const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
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 46d893fcbe8..66c9b9614f3 100644
--- a/arch/arm/mach-exynos/exynos.c
+++ b/arch/arm/mach-exynos/exynos.c
@@ -335,6 +335,15 @@ static void __init exynos_reserve(void)
#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_MACHINE_START(EXYNOS_DT, "SAMSUNG EXYNOS (Flattened Device Tree)")
.dt_compat = exynos_dt_compat,
.restart = exynos_restart,
.reserve = exynos_reserve,
+ .dt_fixup = exynos_dt_fixup,
MACHINE_END