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 lauraa@codeaurora.org --- drivers/of/fdt.c | 18 +++++++++++++++++- include/linux/of_fdt.h | 2 ++ 2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index c4cddf0..55bfca9 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -922,7 +922,7 @@ 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; @@ -936,6 +936,12 @@ bool __init early_init_dt_scan(void *params) return false; }
+ return true; +} + + +void __init early_init_dt_scan_all(void) +{ /* Retrieve various information from the /chosen node */ of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
@@ -944,7 +950,17 @@ 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_all(); return true; }
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index 0511789..d600993 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_all(void);
extern const char *of_flat_dt_get_machine_name(void); extern const void *of_flat_dt_match_machine(const void *default_match,
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 lauraa@codeaurora.org --- drivers/of/fdt.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_fdt.h | 1 + 2 files changed, 49 insertions(+)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 55bfca9..fd5db5a 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 diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index d600993..1aea25c 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; }
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 --- arch/arm/include/asm/mach/arch.h | 1 + arch/arm/kernel/devtree.c | 7 ++++++- arch/arm/mach-exynos/exynos.c | 10 ++++++++++ 3 files changed, 17 insertions(+), 1 deletion(-)
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..893db60 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 +237,11 @@ const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys) dump_machine_table(); /* does not return */ }
+ if (mdesc->dt_fixup) + mdesc->dt_fixup(); + + early_init_dt_scan_all(); + /* 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 f38cf7c..5a7b5c3 100644 --- a/arch/arm/mach-exynos/exynos.c +++ b/arch/arm/mach-exynos/exynos.c @@ -337,6 +337,15 @@ 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 */ @@ -350,4 +359,5 @@ 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
On 07/02/2014 07:33 AM, Laura Abbott wrote:
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 lauraa@codeaurora.org
Tested the patchset on top of Linus' tree.
Verified after enabling following debug message. --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -865,7 +865,7 @@ int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
endp = reg + (l / sizeof(__be32));
- pr_debug("memory scan node %s, reg size %d, data: %x %x %x %x,\n", + pr_err("memory scan node %s, reg size %d, data: %x %x %x %x,\n",
Output before: memory scan node memory, reg size 96, data: 20 10 30 10,
Output after: memory scan node memory, reg size 64, data: 20 10 30 10,
Tested-by: Tushar Behera trblinux@gmail.com
One minor nit below ...
drivers/of/fdt.c | 18 +++++++++++++++++- include/linux/of_fdt.h | 2 ++ 2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index c4cddf0..55bfca9 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -922,7 +922,7 @@ 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; @@ -936,6 +936,12 @@ bool __init early_init_dt_scan(void *params) return false; }
- return true;
+}
Extra blank line here. Can be removed.
On 7/1/2014 7:03 PM, Laura Abbott wrote:
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 lauraa@codeaurora.org
I haven't heard anything more on this series but the holiday weekend in the US probably affected that.
Grant/Rob are you okay with taking this through the devicetree tree if this gets a few more acks or would you rather this go through an ARM tree?
Thanks, Laura
linaro-kernel@lists.linaro.org
-
Laura Abbott -
Tushar Behera