From 4972a74b888c6b52ca41fae6076786dbbeb746d5 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 15 Jul 2014 10:03:34 -0700 Subject: of: Split early_init_dt_scan into two parts MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, early_init_dt_scan validates the header, sets the boot params, and scans for chosen/memory all in one function. Split this up into two separate functions (validation/setting boot params in one, scanning in another) to allow for additional setup between boot params and scanning the memory. Signed-off-by: Laura Abbott Tested-by: Andreas Färber [glikely: s/early_init_dt_scan_all/early_init_dt_scan_nodes/] Signed-off-by: Grant Likely diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index b777d8f..ecc7a02 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -937,7 +937,7 @@ int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base, } #endif -bool __init early_init_dt_scan(void *params) +bool __init early_init_dt_verify(void *params) { if (!params) return false; @@ -951,6 +951,12 @@ bool __init early_init_dt_scan(void *params) 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 +965,17 @@ bool __init early_init_dt_scan(void *params) /* 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..ebb2449 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -73,6 +73,8 @@ extern int early_init_dt_scan_root(unsigned long node, const char *uname, 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, -- cgit v0.10.2 From 704033cee2e5b3c1c6eaf5bb398e465a9c3667b5 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 15 Jul 2014 10:03:35 -0700 Subject: of: Add memory limiting function for flattened devicetrees MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Buggy bootloaders may pass bogus memory entries in the devicetree. Add of_fdt_limit_memory to add an upper bound on the number of entries that can be present in the devicetree. Signed-off-by: Laura Abbott Tested-by: Andreas Färber Signed-off-by: Grant Likely diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index ecc7a02..9aa012e 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -26,6 +26,54 @@ #include /* for COMMAND_LINE_SIZE */ #include +/* + * 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 diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index ebb2449..0ff360d 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -86,6 +86,7 @@ extern void unflatten_and_copy_device_tree(void); 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; } -- cgit v0.10.2 From 5a12a597a8627b91fd9d94365853f9f69a4f399c Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 15 Jul 2014 10:03:36 -0700 Subject: arm: Add devicetree fixup machine function MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Tested-by: Andreas Färber [glikely: Added a comment and fixed up function name] Signed-off-by: Grant Likely 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 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 e94a157..11c54de 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 46d893f..66c9b96 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 -- cgit v0.10.2