From e52f6c389efcc6af67415dc25694b305ebde3d3e Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 15 Jul 2014 10:03:36 -0700 Subject: [PATCH] arm: Add devicetree fixup machine function MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Commit 250a5956213b89ed675e34b6527d8ca982bdf9f3 (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 Tested-by: Andreas Färber [glikely: Added a comment and fixed up function name] Signed-off-by: Grant Likely --- arch/arm/include/asm/mach/arch.h | 1 + arch/arm/kernel/devtree.c | 8 +++++++- arch/arm/mach-exynos/exynos.c | 10 ++++++++++ 3 files changed, 18 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/mach/arch.h b/arch/arm/include/asm/mach/arch.h index 060a75e99263d..0406cb3f1af76 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 e94a157ddff11..11c54de9f8cfa 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 46d893fcbe853..66c9b9614f3cc 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 */ /* Maintainer: Kukjin Kim */ @@ -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 -- 2.39.5