Arch maintainers, please ack/review patches.
This is a resend of a series from Frank last year[1]. I worked in Rob's review comments to unconditionally call unflatten_device_tree() and fixup/audit calls to of_have_populated_dt() so that behavior doesn't change.
I need this series so I can add DT based tests in the clk framework. Either I can merge it through the clk tree once everyone is happy, or Rob can merge it through the DT tree and provide some branch so I can base clk patches on it.
Changes from Frank's series[1]: * Add a DTB loaded kunit test * Make of_have_populated_dt() return false if the DTB isn't from the bootloader * Architecture calls made unconditional so that a root node is always made
Changes from v1 (https://lore.kernel.org/r/20240112200750.4062441-1-sboyd@kernel.org): * x86 patch included * arm64 knocks out initial dtb if acpi is in use * keep Kconfig hidden but def_bool enabled otherwise
Frank Rowand (2): of: Create of_root if no dtb provided by firmware of: unittest: treat missing of_root as error instead of fixing up
Stephen Boyd (5): arm64: Unconditionally call unflatten_device_tree() um: Unconditionally call unflatten_device_tree() x86/of: Unconditionally call unflatten_and_copy_device_tree() of: Always unflatten in unflatten_and_copy_device_tree() of: Add KUnit test to confirm DTB is loaded
arch/arm64/kernel/setup.c | 7 +++-- arch/um/kernel/dtb.c | 14 +++++----- arch/x86/kernel/devicetree.c | 24 +++++++++-------- drivers/of/.kunitconfig | 3 +++ drivers/of/Kconfig | 11 +++++++- drivers/of/Makefile | 4 ++- drivers/of/empty_root.dts | 6 +++++ drivers/of/fdt.c | 52 +++++++++++++++++++++++++----------- drivers/of/of_test.c | 48 +++++++++++++++++++++++++++++++++ drivers/of/platform.c | 3 --- drivers/of/unittest.c | 16 +++-------- include/linux/of.h | 25 ++++++++++------- 12 files changed, 151 insertions(+), 62 deletions(-) create mode 100644 drivers/of/.kunitconfig create mode 100644 drivers/of/empty_root.dts create mode 100644 drivers/of/of_test.c
Cc: Anton Ivanov anton.ivanov@cambridgegreys.com Cc: Brendan Higgins brendan.higgins@linux.dev Cc: Catalin Marinas catalin.marinas@arm.com Cc: David Gow davidgow@google.com Cc: Frank Rowand frowand.list@gmail.com Cc: Johannes Berg johannes@sipsolutions.net Cc: Richard Weinberger richard@nod.at Cc: Rob Herring robh+dt@kernel.org Cc: Will Deacon will@kernel.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Ingo Molnar mingo@redhat.com Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: x86@kernel.org Cc: "H. Peter Anvin" hpa@zytor.com Cc: Saurabh Sengar ssengar@linux.microsoft.com
[1] https://lore.kernel.org/r/20230317053415.2254616-1-frowand.list@gmail.com
base-commit: 0dd3ee31125508cd67f7e7172247f05b7fd1753a
Call this function unconditionally so that we can populate an empty DTB on platforms that don't boot with a firmware provided or builtin DTB. Override 'initial_boot_params' to NULL when ACPI is in use but the bootloader has loaded a DTB so that we don't allow both ACPI and DT to be used during boot. If there isn't a valid initial_boot_params dtb then unflatten_device_tree() returns early so this is fine.
Cc: Rob Herring robh+dt@kernel.org Cc: Frank Rowand frowand.list@gmail.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Stephen Boyd sboyd@kernel.org --- arch/arm64/kernel/setup.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 417a8a86b2db..ffb1942724ae 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -351,8 +351,11 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) /* Parse the ACPI tables for possible boot-time configuration */ acpi_boot_table_init();
- if (acpi_disabled) - unflatten_device_tree(); + /* Don't use the FDT from boot if ACPI is in use */ + if (!acpi_disabled) + initial_boot_params = NULL; + + unflatten_device_tree();
bootmem_init();
On Mon, Jan 29, 2024 at 04:45:00PM -0800, Stephen Boyd wrote:
Call this function unconditionally so that we can populate an empty DTB on platforms that don't boot with a firmware provided or builtin DTB. Override 'initial_boot_params' to NULL when ACPI is in use but the bootloader has loaded a DTB so that we don't allow both ACPI and DT to be used during boot. If there isn't a valid initial_boot_params dtb then unflatten_device_tree() returns early so this is fine.
Cc: Rob Herring robh+dt@kernel.org Cc: Frank Rowand frowand.list@gmail.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Stephen Boyd sboyd@kernel.org
arch/arm64/kernel/setup.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 417a8a86b2db..ffb1942724ae 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -351,8 +351,11 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) /* Parse the ACPI tables for possible boot-time configuration */ acpi_boot_table_init();
- if (acpi_disabled)
unflatten_device_tree();
- /* Don't use the FDT from boot if ACPI is in use */
- if (!acpi_disabled)
initial_boot_params = NULL;
I still think this is a problem for kexec. See of_kexec_alloc_and_setup_fdt(). You see it uses initial_boot_params. At first glance it looks like it would just write out everything we need. But for UEFI boot, I think we need all the chosen properties like linux,uefi-mmap-start preserved from the current boot for the next kernel we kexec.
I think you'll have to check acpi_disabled in unflatten_device_tree() and unflatten the empty tree leaving initial_boot_params alone. That means our FDT and unflattened tree will be different DTs, but I think that's fine.
Rob
Quoting Rob Herring (2024-01-31 12:54:05)
On Mon, Jan 29, 2024 at 04:45:00PM -0800, Stephen Boyd wrote:
Call this function unconditionally so that we can populate an empty DTB on platforms that don't boot with a firmware provided or builtin DTB. Override 'initial_boot_params' to NULL when ACPI is in use but the bootloader has loaded a DTB so that we don't allow both ACPI and DT to be used during boot. If there isn't a valid initial_boot_params dtb then unflatten_device_tree() returns early so this is fine.
Cc: Rob Herring robh+dt@kernel.org Cc: Frank Rowand frowand.list@gmail.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Stephen Boyd sboyd@kernel.org
arch/arm64/kernel/setup.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 417a8a86b2db..ffb1942724ae 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -351,8 +351,11 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) /* Parse the ACPI tables for possible boot-time configuration */ acpi_boot_table_init();
if (acpi_disabled)unflatten_device_tree();
/* Don't use the FDT from boot if ACPI is in use */if (!acpi_disabled)initial_boot_params = NULL;I still think this is a problem for kexec. See of_kexec_alloc_and_setup_fdt(). You see it uses initial_boot_params. At first glance it looks like it would just write out everything we need. But for UEFI boot, I think we need all the chosen properties like linux,uefi-mmap-start preserved from the current boot for the next kernel we kexec.
Ok, got it.
I think you'll have to check acpi_disabled in unflatten_device_tree() and unflatten the empty tree leaving initial_boot_params alone. That means our FDT and unflattened tree will be different DTs, but I think that's fine.
It's sort of scary given that 'initial_boot_params' is an exported global. Maybe that should be hidden away and accessed with a function instead so that this mismatch doesn't break something later on?
On Wed, Jan 31, 2024 at 02:59:53PM -0800, Stephen Boyd wrote:
Quoting Rob Herring (2024-01-31 12:54:05)
On Mon, Jan 29, 2024 at 04:45:00PM -0800, Stephen Boyd wrote:
Call this function unconditionally so that we can populate an empty DTB on platforms that don't boot with a firmware provided or builtin DTB. Override 'initial_boot_params' to NULL when ACPI is in use but the bootloader has loaded a DTB so that we don't allow both ACPI and DT to be used during boot. If there isn't a valid initial_boot_params dtb then unflatten_device_tree() returns early so this is fine.
Cc: Rob Herring robh+dt@kernel.org Cc: Frank Rowand frowand.list@gmail.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Stephen Boyd sboyd@kernel.org
arch/arm64/kernel/setup.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 417a8a86b2db..ffb1942724ae 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -351,8 +351,11 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) /* Parse the ACPI tables for possible boot-time configuration */ acpi_boot_table_init();
if (acpi_disabled)unflatten_device_tree();
/* Don't use the FDT from boot if ACPI is in use */if (!acpi_disabled)initial_boot_params = NULL;I still think this is a problem for kexec. See of_kexec_alloc_and_setup_fdt(). You see it uses initial_boot_params. At first glance it looks like it would just write out everything we need. But for UEFI boot, I think we need all the chosen properties like linux,uefi-mmap-start preserved from the current boot for the next kernel we kexec.
Ok, got it.
I think you'll have to check acpi_disabled in unflatten_device_tree() and unflatten the empty tree leaving initial_boot_params alone. That means our FDT and unflattened tree will be different DTs, but I think that's fine.
It's sort of scary given that 'initial_boot_params' is an exported global. Maybe that should be hidden away and accessed with a function instead so that this mismatch doesn't break something later on?
What you see now is after I did a pass of minimizing the number of users.
BTW, I've now got another use for unconditionally calling unflatten_device_tree() with this[1].
Rob
[1] https://lore.kernel.org/all/20240201194653.GA1328565-robh@kernel.org/
Call this function unconditionally so that we can populate an empty DTB on platforms that don't boot with a command line provided DTB. There's no harm in calling unflatten_device_tree() unconditionally. If there isn't a valid initial_boot_params dtb then unflatten_device_tree() returns early.
Cc: Rob Herring robh+dt@kernel.org Cc: Frank Rowand frowand.list@gmail.com Cc: Richard Weinberger richard@nod.at Cc: Anton Ivanov anton.ivanov@cambridgegreys.com Cc: Johannes Berg johannes@sipsolutions.net Cc: linux-um@lists.infradead.org Signed-off-by: Stephen Boyd sboyd@kernel.org --- arch/um/kernel/dtb.c | 14 +++++++------- drivers/of/unittest.c | 4 ---- 2 files changed, 7 insertions(+), 11 deletions(-)
diff --git a/arch/um/kernel/dtb.c b/arch/um/kernel/dtb.c index 484141b06938..4954188a6a09 100644 --- a/arch/um/kernel/dtb.c +++ b/arch/um/kernel/dtb.c @@ -16,16 +16,16 @@ void uml_dtb_init(void) void *area;
area = uml_load_file(dtb, &size); - if (!area) - return; + if (area) { + if (!early_init_dt_scan(area)) { + pr_err("invalid DTB %s\n", dtb); + memblock_free(area, size); + return; + }
- if (!early_init_dt_scan(area)) { - pr_err("invalid DTB %s\n", dtb); - memblock_free(area, size); - return; + early_init_fdt_scan_reserved_mem(); }
- early_init_fdt_scan_reserved_mem(); unflatten_device_tree(); }
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c index e9e90e96600e..a8b27dd16ecf 100644 --- a/drivers/of/unittest.c +++ b/drivers/of/unittest.c @@ -4075,10 +4075,6 @@ static int __init of_unittest(void) add_taint(TAINT_TEST, LOCKDEP_STILL_OK);
/* adding data for unittest */ - - if (IS_ENABLED(CONFIG_UML)) - unittest_unflatten_overlay_base(); - res = unittest_data_add(); if (res) return res;
Call this function unconditionally so that we can populate an empty DTB on platforms that don't boot with a firmware provided or builtin DTB.
Cc: Rob Herring robh+dt@kernel.org Cc: Frank Rowand frowand.list@gmail.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Ingo Molnar mingo@redhat.com Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: x86@kernel.org Cc: "H. Peter Anvin" hpa@zytor.com Cc: Saurabh Sengar ssengar@linux.microsoft.com Signed-off-by: Stephen Boyd sboyd@kernel.org --- arch/x86/kernel/devicetree.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c index afd09924094e..650752d112a6 100644 --- a/arch/x86/kernel/devicetree.c +++ b/arch/x86/kernel/devicetree.c @@ -283,22 +283,24 @@ void __init x86_flattree_get_config(void) u32 size, map_len; void *dt;
- if (!initial_dtb) - return; + if (initial_dtb) { + map_len = max(PAGE_SIZE - (initial_dtb & ~PAGE_MASK), (u64)128);
- map_len = max(PAGE_SIZE - (initial_dtb & ~PAGE_MASK), (u64)128); + dt = early_memremap(initial_dtb, map_len); + size = fdt_totalsize(dt); + if (map_len < size) { + early_memunmap(dt, map_len); + dt = early_memremap(initial_dtb, size); + map_len = size; + }
- dt = early_memremap(initial_dtb, map_len); - size = fdt_totalsize(dt); - if (map_len < size) { - early_memunmap(dt, map_len); - dt = early_memremap(initial_dtb, size); - map_len = size; + early_init_dt_verify(dt); }
- early_init_dt_verify(dt); unflatten_and_copy_device_tree(); - early_memunmap(dt, map_len); + + if (initial_dtb) + early_memunmap(dt, map_len); } #endif
On Mon, Jan 29, 2024 at 04:45:02PM -0800, Stephen Boyd wrote:
Call this function unconditionally so that we can populate an empty DTB on platforms that don't boot with a firmware provided or builtin DTB.
Cc: Rob Herring robh+dt@kernel.org Cc: Frank Rowand frowand.list@gmail.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Ingo Molnar mingo@redhat.com Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: x86@kernel.org Cc: "H. Peter Anvin" hpa@zytor.com Cc: Saurabh Sengar ssengar@linux.microsoft.com Signed-off-by: Stephen Boyd sboyd@kernel.org
arch/x86/kernel/devicetree.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c index afd09924094e..650752d112a6 100644 --- a/arch/x86/kernel/devicetree.c +++ b/arch/x86/kernel/devicetree.c @@ -283,22 +283,24 @@ void __init x86_flattree_get_config(void) u32 size, map_len; void *dt;
- if (!initial_dtb)
return;
- if (initial_dtb) {
map_len = max(PAGE_SIZE - (initial_dtb & ~PAGE_MASK), (u64)128);
- map_len = max(PAGE_SIZE - (initial_dtb & ~PAGE_MASK), (u64)128);
dt = early_memremap(initial_dtb, map_len);size = fdt_totalsize(dt);if (map_len < size) {early_memunmap(dt, map_len);dt = early_memremap(initial_dtb, size);map_len = size;}
- dt = early_memremap(initial_dtb, map_len);
- size = fdt_totalsize(dt);
- if (map_len < size) {
early_memunmap(dt, map_len);dt = early_memremap(initial_dtb, size);map_len = size;
early_init_dt_verify(dt);
- early_init_dt_verify(dt); unflatten_and_copy_device_tree();
- early_memunmap(dt, map_len);
- if (initial_dtb)
early_memunmap(dt, map_len);} #endif -- https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/ https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git
Tested the series in Hyper-V environment. Please feel free to add: Tested-by: Saurabh Sengar ssengar@linux.microsoft.com
We want to populate an empty DT whenever CONFIG_OF is enabled so that overlays can be applied and the DT unit tests can be run. Make unflatten_and_copy_device_tree() stop printing a warning if the 'initial_boot_params' pointer is NULL. Instead, simply copy the dtb if there is one and then unflatten it. If there isn't a DT to copy, then the call to unflatten_device_tree() is largely a no-op, so nothing really changes here.
Cc: Rob Herring robh+dt@kernel.org Cc: Frank Rowand frowand.list@gmail.com Signed-off-by: Stephen Boyd sboyd@kernel.org --- drivers/of/fdt.c | 32 +++++++++++++++++--------------- 1 file changed, 17 insertions(+), 15 deletions(-)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index bf502ba8da95..b488ad86d456 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -1318,6 +1318,21 @@ bool __init early_init_dt_scan(void *params) return true; }
+static void __init copy_device_tree(void) +{ + int size; + void *dt; + + size = fdt_totalsize(initial_boot_params); + dt = early_init_dt_alloc_memory_arch(size, + roundup_pow_of_two(FDT_V17_SIZE)); + + if (dt) { + memcpy(dt, initial_boot_params, size); + initial_boot_params = dt; + } +} + /** * unflatten_device_tree - create tree of device_nodes from flat blob * @@ -1350,22 +1365,9 @@ void __init unflatten_device_tree(void) */ void __init unflatten_and_copy_device_tree(void) { - int size; - void *dt; + if (initial_boot_params) + copy_device_tree();
- if (!initial_boot_params) { - pr_warn("No valid device tree found, continuing without\n"); - return; - } - - size = fdt_totalsize(initial_boot_params); - dt = early_init_dt_alloc_memory_arch(size, - roundup_pow_of_two(FDT_V17_SIZE)); - - if (dt) { - memcpy(dt, initial_boot_params, size); - initial_boot_params = dt; - } unflatten_device_tree(); }
From: Frank Rowand frowand.list@gmail.com
When enabling CONFIG_OF on a platform where 'of_root' is not populated by firmware, we end up without a root node. In order to apply overlays and create subnodes of the root node, we need one. Create this root node by unflattening an empty builtin dtb.
If firmware provides a flattened device tree (FDT) then the FDT is unflattened via setup_arch(). Otherwise, the call to unflatten(_and_copy)?_device_tree() will create an empty root node.
We make of_have_populated_dt() return true only if the DTB was loaded by firmware so that existing callers don't change behavior after this patch. The call in the of platform code is removed because it prevents overlays from creating platform devices when the platform bus isn't fully initialized.
Signed-off-by: Frank Rowand frowand.list@gmail.com Link: https://lore.kernel.org/r/20230317053415.2254616-2-frowand.list@gmail.com Cc: Rob Herring robh+dt@kernel.org [sboyd@kernel.org: Update of_have_populated_dt() to treat this empty dtb as not populated. Drop setup_of() initcall] Signed-off-by: Stephen Boyd sboyd@kernel.org --- drivers/of/Kconfig | 2 +- drivers/of/Makefile | 2 +- drivers/of/empty_root.dts | 6 ++++++ drivers/of/fdt.c | 20 ++++++++++++++++++++ drivers/of/platform.c | 3 --- include/linux/of.h | 25 +++++++++++++++---------- 6 files changed, 43 insertions(+), 15 deletions(-) create mode 100644 drivers/of/empty_root.dts
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index da9826accb1b..17733285b415 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -54,7 +54,7 @@ config OF_FLATTREE select CRC32
config OF_EARLY_FLATTREE - bool + def_bool OF && !SPARC 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 b488ad86d456..f7dd7fd68d4d 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -32,6 +32,13 @@
#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 @@ -1343,6 +1350,19 @@ static void __init copy_device_tree(void) */ void __init unflatten_device_tree(void) { + if (!initial_boot_params) { + initial_boot_params = (void *) __dtb_empty_root_begin; + /* fdt_totalsize() will be used for copy size */ + if (fdt_totalsize(initial_boot_params) > + __dtb_empty_root_end - __dtb_empty_root_begin) { + pr_err("invalid size in dtb_empty_root\n"); + return; + } + of_fdt_crc32 = crc32_be(~0, initial_boot_params, + fdt_totalsize(initial_boot_params)); + copy_device_tree(); + } + __unflatten_device_tree(initial_boot_params, NULL, &of_root, early_init_dt_alloc_memory_arch, false);
diff --git a/drivers/of/platform.c b/drivers/of/platform.c index 126d265aa7d8..20087bb8a46b 100644 --- a/drivers/of/platform.c +++ b/drivers/of/platform.c @@ -549,9 +549,6 @@ 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 6a9ddf20e79a..52f6ad6a1c8c 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); @@ -549,11 +544,6 @@ 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 */
From: Frank Rowand frowand.list@gmail.com
unflatten_device_tree() now ensures that the 'of_root' node is populated with the root of a default empty devicetree. Remove the unittest code that created 'of_root' if it was missing. Verify that 'of_root' is valid before attempting to attach the testcase-data subtree. Remove the unittest code that unflattens the unittest overlay base if architecture is UML because that is always done now.
Signed-off-by: Frank Rowand frowand.list@gmail.com Link: https://lore.kernel.org/r/20230317053415.2254616-3-frowand.list@gmail.com Cc: Rob Herring robh+dt@kernel.org Signed-off-by: Stephen Boyd sboyd@kernel.org --- drivers/of/unittest.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c index a8b27dd16ecf..742d919e8ab4 100644 --- a/drivers/of/unittest.c +++ b/drivers/of/unittest.c @@ -1732,20 +1732,16 @@ static int __init unittest_data_add(void) return -EINVAL; }
+ /* attach the sub-tree to live tree */ if (!of_root) { - of_root = unittest_data_node; - for_each_of_allnodes(np) - __of_attach_node_sysfs(np); - of_aliases = of_find_node_by_path("/aliases"); - of_chosen = of_find_node_by_path("/chosen"); - of_overlay_mutex_unlock(); - return 0; + pr_warn("%s: no live tree to attach sub-tree\n", __func__); + kfree(unittest_data); + return -ENODEV; }
EXPECT_BEGIN(KERN_INFO, "Duplicate name in testcase-data, renamed to "duplicate-name#1"");
- /* attach the sub-tree to live tree */ np = unittest_data_node->child; while (np) { struct device_node *next = np->sibling;
Add a KUnit test that confirms a DTB has been loaded, i.e. there is a root node, and that the of_have_populated_dt() API works properly.
Cc: Rob Herring robh+dt@kernel.org Cc: Frank Rowand frowand.list@gmail.com Cc: David Gow davidgow@google.com Cc: Brendan Higgins brendan.higgins@linux.dev Signed-off-by: Stephen Boyd sboyd@kernel.org --- drivers/of/.kunitconfig | 3 +++ drivers/of/Kconfig | 9 ++++++++ drivers/of/Makefile | 2 ++ drivers/of/of_test.c | 48 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 62 insertions(+) create mode 100644 drivers/of/.kunitconfig create mode 100644 drivers/of/of_test.c
diff --git a/drivers/of/.kunitconfig b/drivers/of/.kunitconfig new file mode 100644 index 000000000000..5a8fee11978c --- /dev/null +++ b/drivers/of/.kunitconfig @@ -0,0 +1,3 @@ +CONFIG_KUNIT=y +CONFIG_OF=y +CONFIG_OF_KUNIT_TEST=y diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index 17733285b415..53d1b5dd89e8 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -37,6 +37,15 @@ config OF_UNITTEST
If unsure, say N here. This option is not safe to enable.
+config OF_KUNIT_TEST + tristate "Devicetree KUnit Test" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS + help + This option builds KUnit unit tests for device tree infrastructure. + + If unsure, say N here, but this option is safe to enable. + config OF_ALL_DTBS bool "Build all Device Tree Blobs" depends on COMPILE_TEST diff --git a/drivers/of/Makefile b/drivers/of/Makefile index df305348d1cb..251d33532148 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -19,4 +19,6 @@ obj-y += kexec.o endif endif
+obj-$(CONFIG_OF_KUNIT_TEST) += of_test.o + obj-$(CONFIG_OF_UNITTEST) += unittest-data/ diff --git a/drivers/of/of_test.c b/drivers/of/of_test.c new file mode 100644 index 000000000000..71a767b42b43 --- /dev/null +++ b/drivers/of/of_test.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KUnit tests for OF APIs + */ +#include <linux/module.h> +#include <linux/of.h> + +#include <kunit/test.h> + +/* + * Test that the root node "/" can be found by path. + */ +static void dtb_root_node_found_by_path(struct kunit *test) +{ + struct device_node *np; + + np = of_find_node_by_path("/"); + KUNIT_EXPECT_NOT_ERR_OR_NULL(test, np); + of_node_put(np); +} + +/* + * Test that the 'of_root' global variable is always populated when DT code is + * enabled. + */ +static void dtb_root_node_populates_of_root(struct kunit *test) +{ + KUNIT_EXPECT_NOT_ERR_OR_NULL(test, of_root); +} + +static struct kunit_case dtb_test_cases[] = { + KUNIT_CASE(dtb_root_node_found_by_path), + KUNIT_CASE(dtb_root_node_populates_of_root), + {} +}; + +/* + * Test suite to confirm a DTB is loaded. + */ +static struct kunit_suite dtb_suite = { + .name = "dtb", + .test_cases = dtb_test_cases, +}; + +kunit_test_suites( + &dtb_suite, +); +MODULE_LICENSE("GPL");
linux-kselftest-mirror@lists.linaro.org
-
Rob Herring -
Saurabh Singh Sengar -
Stephen Boyd