diff options
| -rw-r--r-- | drivers/of/Kconfig | 5 | ||||
| -rw-r--r-- | drivers/of/Makefile | 2 | ||||
| -rw-r--r-- | drivers/of/empty_root.dts | 6 | ||||
| -rw-r--r-- | drivers/of/fdt.c | 32 | ||||
| -rw-r--r-- | drivers/of/platform.c | 3 | ||||
| -rw-r--r-- | include/linux/of.h | 25 |
6 files changed, 55 insertions, 18 deletions
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index da9826accb1b..d738fbad9c36 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -14,9 +14,8 @@ if OF config OF_UNITTEST bool "Device Tree runtime unit tests" - depends on !SPARC + depends on OF_EARLY_FLATTREE select IRQ_DOMAIN - select OF_EARLY_FLATTREE select OF_RESOLVE help This option builds in test cases for the device tree infrastructure @@ -54,7 +53,7 @@ config OF_FLATTREE select CRC32 config OF_EARLY_FLATTREE - bool + def_bool OF && !(SPARC || ALPHA || HEXAGON || M68K || PARISC || S390) select DMA_DECLARE_COHERENT if HAS_DMA && HAS_IOMEM select OF_FLATTREE diff --git a/drivers/of/Makefile b/drivers/of/Makefile index eff624854575..df305348d1cb 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -2,7 +2,7 @@ obj-y = base.o cpu.o device.o module.o platform.o property.o obj-$(CONFIG_OF_KOBJ) += kobj.o obj-$(CONFIG_OF_DYNAMIC) += dynamic.o -obj-$(CONFIG_OF_FLATTREE) += fdt.o +obj-$(CONFIG_OF_FLATTREE) += fdt.o empty_root.dtb.o obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o obj-$(CONFIG_OF_PROMTREE) += pdt.o obj-$(CONFIG_OF_ADDRESS) += address.o diff --git a/drivers/of/empty_root.dts b/drivers/of/empty_root.dts new file mode 100644 index 000000000000..cf9e97a60f48 --- /dev/null +++ b/drivers/of/empty_root.dts @@ -0,0 +1,6 @@ +// SPDX-License-Identifier: GPL-2.0-only +/dts-v1/; + +/ { + +}; diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index dfeba8b8ce94..e5a385285149 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -8,6 +8,7 @@ #define pr_fmt(fmt) "OF: fdt: " fmt +#include <linux/acpi.h> #include <linux/crash_dump.h> #include <linux/crc32.h> #include <linux/kernel.h> @@ -33,6 +34,13 @@ #include "of_private.h" /* + * __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by + * cmd_dt_S_dtb in scripts/Makefile.lib + */ +extern uint8_t __dtb_empty_root_begin[]; +extern uint8_t __dtb_empty_root_end[]; + +/* * of_fdt_limit_memory - limit the number of regions in the /memory node * @limit: maximum entries * @@ -1343,7 +1351,29 @@ static void *__init copy_device_tree(void *fdt) */ void __init unflatten_device_tree(void) { - __unflatten_device_tree(initial_boot_params, NULL, &of_root, + void *fdt = initial_boot_params; + + /* Don't use the bootloader provided DTB if ACPI is enabled */ + if (!acpi_disabled) + fdt = NULL; + + /* + * Populate an empty root node when ACPI is enabled or bootloader + * doesn't provide one. + */ + if (!fdt) { + fdt = (void *) __dtb_empty_root_begin; + /* fdt_totalsize() will be used for copy size */ + if (fdt_totalsize(fdt) > + __dtb_empty_root_end - __dtb_empty_root_begin) { + pr_err("invalid size in dtb_empty_root\n"); + return; + } + of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt)); + fdt = copy_device_tree(fdt); + } + + __unflatten_device_tree(fdt, NULL, &of_root, early_init_dt_alloc_memory_arch, false); /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ diff --git a/drivers/of/platform.c b/drivers/of/platform.c index ba964df6b6db..389d4ea6bfc1 100644 --- a/drivers/of/platform.c +++ b/drivers/of/platform.c @@ -512,9 +512,6 @@ static int __init of_platform_default_populate_init(void) device_links_supplier_sync_state_pause(); - if (!of_have_populated_dt()) - return -ENODEV; - if (IS_ENABLED(CONFIG_PPC)) { struct device_node *boot_display = NULL; struct platform_device *dev; diff --git a/include/linux/of.h b/include/linux/of.h index a3e8e429ad7f..d5e7acdc8c8e 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -180,11 +180,6 @@ static inline bool is_of_node(const struct fwnode_handle *fwnode) &__of_fwnode_handle_node->fwnode : NULL; \ }) -static inline bool of_have_populated_dt(void) -{ - return of_root != NULL; -} - static inline bool of_node_is_root(const struct device_node *node) { return node && (node->parent == NULL); @@ -546,11 +541,6 @@ static inline struct device_node *of_find_node_with_property( #define of_fwnode_handle(node) NULL -static inline bool of_have_populated_dt(void) -{ - return false; -} - static inline struct device_node *of_get_compatible_child(const struct device_node *parent, const char *compatible) { @@ -1634,6 +1624,21 @@ static inline bool of_device_is_system_power_controller(const struct device_node return of_property_read_bool(np, "system-power-controller"); } +/** + * of_have_populated_dt() - Has DT been populated by bootloader + * + * Return: True if a DTB has been populated by the bootloader and it isn't the + * empty builtin one. False otherwise. + */ +static inline bool of_have_populated_dt(void) +{ +#ifdef CONFIG_OF + return of_property_present(of_root, "compatible"); +#else + return false; +#endif +} + /* * Overlay support */ |