[PATCH v2] of: reserved_mem: Restructure code to call reserved mem init functions earlier

Oreoluwa Babatunde posted 1 patch 1 year, 5 months ago
drivers/of/fdt.c             |  2 +-
drivers/of/of_private.h      |  2 +-
drivers/of/of_reserved_mem.c | 83 +++++++++++++++++++++---------------
3 files changed, 50 insertions(+), 37 deletions(-)
[PATCH v2] of: reserved_mem: Restructure code to call reserved mem init functions earlier
Posted by Oreoluwa Babatunde 1 year, 5 months ago
After all the reserved memory regions have been added to the
reserved_mem array, a region specific initialization function is called
on each of reserved memory regions in a loop to initialize them.

With recent changes made to allow the reserved_mem array be dynamically
allocated, the cma reserved memory regions are not initialized until
after the page tables are setup. This causes the warning seen in the
dump stack below:

	WARNING: CPU: 0 PID: 1 at mm/memory.c:2789 __apply_to_page_range+0x360/0x380
	CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-rc1-00007-ga46cccb0ee2d #1
	Hardware name: Generic DT based system
	Call trace:
	unwind_backtrace from show_stack+0x18/0x1c
	show_stack from dump_stack_lvl+0x54/0x68
	dump_stack_lvl from __warn+0x74/0x114
	__warn from warn_slowpath_fmt+0x13c/0x1c0
	warn_slowpath_fmt from __apply_to_page_range+0x360/0x380
	__apply_to_page_range from apply_to_page_range+0x24/0x2c
	apply_to_page_range from __alloc_from_contiguous+0xc4/0x158
	__alloc_from_contiguous from cma_allocator_alloc+0x3c/0x44
	cma_allocator_alloc from arch_dma_alloc+0x128/0x2b4
	arch_dma_alloc from dma_alloc_attrs+0x90/0x150
	dma_alloc_attrs from drm_gem_dma_create+0xa4/0x13c
	drm_gem_dma_create from drm_gem_dma_create_with_handle+0x24/0xac
	drm_gem_dma_create_with_handle from drm_gem_dma_dumb_create+0x44/0x50
	drm_gem_dma_dumb_create from drm_client_framebuffer_create+0x9c/0x164
	drm_client_framebuffer_create from drm_fbdev_dma_helper_fb_probe+0x84/0x23c
	drm_fbdev_dma_helper_fb_probe from __drm_fb_helper_initial_config_and_unlock+0x2e4/0x4f8
	__drm_fb_helper_initial_config_and_unlock from drm_fbdev_dma_client_hotplug+0x74/0xb8
	drm_fbdev_dma_client_hotplug from drm_client_register+0x5c/0x98
	drm_client_register from aspeed_gfx_probe+0x278/0x3c0
	aspeed_gfx_probe from platform_probe+0x60/0xb8
	platform_probe from really_probe+0xd4/0x3b4
	really_probe from __driver_probe_device+0x90/0x1dc
	__driver_probe_device from driver_probe_device+0x38/0xd0
	driver_probe_device from __driver_attach+0x118/0x1dc
	__driver_attach from bus_for_each_dev+0x84/0xd4
	bus_for_each_dev from bus_add_driver+0xec/0x1f0
	bus_add_driver from driver_register+0x84/0x11c
	driver_register from do_one_initcall+0x84/0x1c8
	do_one_initcall from kernel_init_freeable+0x1a4/0x230
	kernel_init_freeable from kernel_init+0x1c/0x138
	kernel_init from ret_from_fork+0x14/0x28
	Exception stack(0x9f015fb0 to 0x9f015ff8)
	5fa0:                                     00000000 00000000 00000000 00000000
	5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
	5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
	---[ end trace 0000000000000000 ]---
	aspeed_gfx 1e6e6000.display: [drm] fb0: aspeed-gfx-drmd frame buffer device

Hence, restructure the code to initialize the regions as soon as each
of them are added to the reserved_mem array.

Fixes: a46cccb0ee2d ("of: reserved_mem: Restruture how the reserved memory regions are processed")
Signed-off-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com>
---
v2:
- Fix kernel-doc for of_init_reserved_mem_node() in response to the
  below warning from v1:
  https://lore.kernel.org/all/202406181626.126X1Nbz-lkp@intel.com/

v1:
  https://lore.kernel.org/all/20240617193357.3929092-1-quic_obabatun@quicinc.com/

 drivers/of/fdt.c             |  2 +-
 drivers/of/of_private.h      |  2 +-
 drivers/of/of_reserved_mem.c | 83 +++++++++++++++++++++---------------
 3 files changed, 50 insertions(+), 37 deletions(-)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 9cde2abd2fc0..ea2dff0478c7 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -1239,7 +1239,7 @@ void __init unflatten_device_tree(void)
 	unittest_unflatten_overlay_base();
 
 	/* initialize the reserved memory regions */
-	of_init_reserved_mem();
+	of_scan_reserved_mem_reg_nodes();
 }
 
 /**
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 01b33c4b1e9f..7412aed903df 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -181,7 +181,7 @@ static inline struct device_node *__of_get_dma_parent(const struct device_node *
 #endif
 
 int fdt_scan_reserved_mem(void);
-void of_init_reserved_mem(void);
+void of_scan_reserved_mem_reg_nodes(void);
 
 bool of_fdt_device_is_available(const void *blob, unsigned long node);
 
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index eb54490a0a11..b31001728866 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -97,6 +97,8 @@ static void __init alloc_reserved_mem_array(void)
 	reserved_mem = new_array;
 }
 
+static void __init of_init_reserved_mem_node(struct reserved_mem *rmem);
+
 /*
  * of_reserved_mem_save_node() - save fdt node for second pass initialization
  */
@@ -115,6 +117,12 @@ static void __init of_reserved_mem_save_node(struct device_node *node, const cha
 	rmem->base = base;
 	rmem->size = size;
 
+	/*
+	 * Run the region specific initialization function for the rmem
+	 * node.
+	 */
+	of_init_reserved_mem_node(rmem);
+
 	reserved_mem_count++;
 	return;
 }
@@ -201,6 +209,8 @@ static int __init __fdt_reserved_mem_check_root(unsigned long node)
 	return 0;
 }
 
+static void __init __rmem_check_for_overlap(void);
+
 /**
  * of_scan_reserved_mem_reg_nodes() - Store info for the "reg" defined
  * reserved memory regions.
@@ -211,7 +221,7 @@ static int __init __fdt_reserved_mem_check_root(unsigned long node)
  * size are all stored in the reserved_mem array by calling the
  * of_reserved_mem_save_node() function.
  */
-static void __init of_scan_reserved_mem_reg_nodes(void)
+void __init of_scan_reserved_mem_reg_nodes(void)
 {
 	struct device_node *node, *child;
 	phys_addr_t base, size;
@@ -222,6 +232,13 @@ static void __init of_scan_reserved_mem_reg_nodes(void)
 		return;
 	}
 
+	/*
+	 * Before moving forward, allocate the exact size needed for the
+	 * reserved_mem array and copy all previously saved contents
+	 * into the new array if successful.
+	 */
+	alloc_reserved_mem_array();
+
 	for_each_child_of_node(node, child) {
 		int ret = 0;
 		const char *uname;
@@ -246,6 +263,8 @@ static void __init of_scan_reserved_mem_reg_nodes(void)
 		if (size)
 			of_reserved_mem_save_node(child, uname, base, size);
 	}
+	/* check for overlapping reserved regions */
+	__rmem_check_for_overlap();
 }
 
 static int __init __reserved_mem_alloc_size(unsigned long node, const char *uname);
@@ -526,44 +545,38 @@ static void __init __rmem_check_for_overlap(void)
 }
 
 /**
- * of_init_reserved_mem() - allocate and init all saved reserved memory regions
+ * of_init_reserved_mem_node() - Initialize a saved reserved memory region.
+ * @rmem: reserved_mem object of the memory region to be initialized.
+ *
+ * This function is used to call the region specific initialization
+ * function on the rmem object passed as an argument. The rmem object
+ * will contain the base address, size, node name, and device_node of
+ * the reserved memory region to be initialized.
  */
-void __init of_init_reserved_mem(void)
+static void __init of_init_reserved_mem_node(struct reserved_mem *rmem)
 {
-	int i;
-
-	alloc_reserved_mem_array();
-
-	of_scan_reserved_mem_reg_nodes();
+	int err;
+	bool nomap;
+	struct device_node *node = rmem->dev_node;
 
-	/* check for overlapping reserved regions */
-	__rmem_check_for_overlap();
+	nomap = of_property_present(node, "no-map");
 
-	for (i = 0; i < reserved_mem_count; i++) {
-		struct reserved_mem *rmem = &reserved_mem[i];
-		struct device_node *node = rmem->dev_node;
-		int err = 0;
-		bool nomap;
-
-		nomap = of_property_present(node, "no-map");
-
-		err = __reserved_mem_init_node(rmem);
-		if (err != 0 && err != -ENOENT) {
-			pr_info("node %s compatible matching fail\n", rmem->name);
-			if (nomap)
-				memblock_clear_nomap(rmem->base, rmem->size);
-			else
-				memblock_phys_free(rmem->base, rmem->size);
-		} else {
-			phys_addr_t end = rmem->base + rmem->size - 1;
-			bool reusable = of_property_present(node, "reusable");
-
-			pr_info("%pa..%pa (%lu KiB) %s %s %s\n",
-				&rmem->base, &end, (unsigned long)(rmem->size / SZ_1K),
-				nomap ? "nomap" : "map",
-				reusable ? "reusable" : "non-reusable",
-				rmem->name ? rmem->name : "unknown");
-		}
+	err = __reserved_mem_init_node(rmem);
+	if (err != 0 && err != -ENOENT) {
+		pr_info("node %s compatible matching fail\n", rmem->name);
+		if (nomap)
+			memblock_clear_nomap(rmem->base, rmem->size);
+		else
+			memblock_phys_free(rmem->base, rmem->size);
+	} else {
+		phys_addr_t end = rmem->base + rmem->size - 1;
+		bool reusable = of_property_present(node, "reusable");
+
+		pr_info("%pa..%pa (%lu KiB) %s %s %s\n",
+			&rmem->base, &end, (unsigned long)(rmem->size / SZ_1K),
+			nomap ? "nomap" : "map",
+			reusable ? "reusable" : "non-reusable",
+			rmem->name ? rmem->name : "unknown");
 	}
 }
 
-- 
2.34.1
Re: [PATCH v2] of: reserved_mem: Restructure code to call reserved mem init functions earlier
Posted by Rob Herring 1 year, 5 months ago
On Wed, Jun 19, 2024 at 05:10:27PM -0700, Oreoluwa Babatunde wrote:
> After all the reserved memory regions have been added to the
> reserved_mem array, a region specific initialization function is called
> on each of reserved memory regions in a loop to initialize them.
> 
> With recent changes made to allow the reserved_mem array be dynamically
> allocated, the cma reserved memory regions are not initialized until
> after the page tables are setup. This causes the warning seen in the
> dump stack below:
> 
> 	WARNING: CPU: 0 PID: 1 at mm/memory.c:2789 __apply_to_page_range+0x360/0x380
> 	CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-rc1-00007-ga46cccb0ee2d #1
> 	Hardware name: Generic DT based system
> 	Call trace:
> 	unwind_backtrace from show_stack+0x18/0x1c
> 	show_stack from dump_stack_lvl+0x54/0x68
> 	dump_stack_lvl from __warn+0x74/0x114
> 	__warn from warn_slowpath_fmt+0x13c/0x1c0
> 	warn_slowpath_fmt from __apply_to_page_range+0x360/0x380
> 	__apply_to_page_range from apply_to_page_range+0x24/0x2c
> 	apply_to_page_range from __alloc_from_contiguous+0xc4/0x158
> 	__alloc_from_contiguous from cma_allocator_alloc+0x3c/0x44
> 	cma_allocator_alloc from arch_dma_alloc+0x128/0x2b4
> 	arch_dma_alloc from dma_alloc_attrs+0x90/0x150
> 	dma_alloc_attrs from drm_gem_dma_create+0xa4/0x13c
> 	drm_gem_dma_create from drm_gem_dma_create_with_handle+0x24/0xac
> 	drm_gem_dma_create_with_handle from drm_gem_dma_dumb_create+0x44/0x50
> 	drm_gem_dma_dumb_create from drm_client_framebuffer_create+0x9c/0x164
> 	drm_client_framebuffer_create from drm_fbdev_dma_helper_fb_probe+0x84/0x23c
> 	drm_fbdev_dma_helper_fb_probe from __drm_fb_helper_initial_config_and_unlock+0x2e4/0x4f8
> 	__drm_fb_helper_initial_config_and_unlock from drm_fbdev_dma_client_hotplug+0x74/0xb8
> 	drm_fbdev_dma_client_hotplug from drm_client_register+0x5c/0x98
> 	drm_client_register from aspeed_gfx_probe+0x278/0x3c0
> 	aspeed_gfx_probe from platform_probe+0x60/0xb8
> 	platform_probe from really_probe+0xd4/0x3b4
> 	really_probe from __driver_probe_device+0x90/0x1dc
> 	__driver_probe_device from driver_probe_device+0x38/0xd0
> 	driver_probe_device from __driver_attach+0x118/0x1dc
> 	__driver_attach from bus_for_each_dev+0x84/0xd4
> 	bus_for_each_dev from bus_add_driver+0xec/0x1f0
> 	bus_add_driver from driver_register+0x84/0x11c
> 	driver_register from do_one_initcall+0x84/0x1c8
> 	do_one_initcall from kernel_init_freeable+0x1a4/0x230
> 	kernel_init_freeable from kernel_init+0x1c/0x138
> 	kernel_init from ret_from_fork+0x14/0x28
> 	Exception stack(0x9f015fb0 to 0x9f015ff8)
> 	5fa0:                                     00000000 00000000 00000000 00000000
> 	5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 	5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> 	---[ end trace 0000000000000000 ]---
> 	aspeed_gfx 1e6e6000.display: [drm] fb0: aspeed-gfx-drmd frame buffer device
> 
> Hence, restructure the code to initialize the regions as soon as each
> of them are added to the reserved_mem array.
> 
> Fixes: a46cccb0ee2d ("of: reserved_mem: Restruture how the reserved memory regions are processed")
> Signed-off-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com>
> ---
> v2:
> - Fix kernel-doc for of_init_reserved_mem_node() in response to the
>   below warning from v1:
>   https://lore.kernel.org/all/202406181626.126X1Nbz-lkp@intel.com/
> 
> v1:
>   https://lore.kernel.org/all/20240617193357.3929092-1-quic_obabatun@quicinc.com/
> 
>  drivers/of/fdt.c             |  2 +-
>  drivers/of/of_private.h      |  2 +-
>  drivers/of/of_reserved_mem.c | 83 +++++++++++++++++++++---------------
>  3 files changed, 50 insertions(+), 37 deletions(-)

Applied.

In the future, do not send fixes or new versions as replies to previous 
threads. The default behavior of b4 is to apply v6 of the series because 
that is the 'newest' version.

Rob
Re: [PATCH v2] of: reserved_mem: Restructure code to call reserved mem init functions earlier
Posted by Oreoluwa Babatunde 1 year, 5 months ago
On 6/26/2024 8:16 AM, Rob Herring wrote:
> On Wed, Jun 19, 2024 at 05:10:27PM -0700, Oreoluwa Babatunde wrote:
>> After all the reserved memory regions have been added to the
>> reserved_mem array, a region specific initialization function is called
>> on each of reserved memory regions in a loop to initialize them.
>>
>> With recent changes made to allow the reserved_mem array be dynamically
>> allocated, the cma reserved memory regions are not initialized until
>> after the page tables are setup. This causes the warning seen in the
>> dump stack below:
>>
>> 	WARNING: CPU: 0 PID: 1 at mm/memory.c:2789 __apply_to_page_range+0x360/0x380
>> 	CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-rc1-00007-ga46cccb0ee2d #1
>> 	Hardware name: Generic DT based system
>> 	Call trace:
>> 	unwind_backtrace from show_stack+0x18/0x1c
>> 	show_stack from dump_stack_lvl+0x54/0x68
>> 	dump_stack_lvl from __warn+0x74/0x114
>> 	__warn from warn_slowpath_fmt+0x13c/0x1c0
>> 	warn_slowpath_fmt from __apply_to_page_range+0x360/0x380
>> 	__apply_to_page_range from apply_to_page_range+0x24/0x2c
>> 	apply_to_page_range from __alloc_from_contiguous+0xc4/0x158
>> 	__alloc_from_contiguous from cma_allocator_alloc+0x3c/0x44
>> 	cma_allocator_alloc from arch_dma_alloc+0x128/0x2b4
>> 	arch_dma_alloc from dma_alloc_attrs+0x90/0x150
>> 	dma_alloc_attrs from drm_gem_dma_create+0xa4/0x13c
>> 	drm_gem_dma_create from drm_gem_dma_create_with_handle+0x24/0xac
>> 	drm_gem_dma_create_with_handle from drm_gem_dma_dumb_create+0x44/0x50
>> 	drm_gem_dma_dumb_create from drm_client_framebuffer_create+0x9c/0x164
>> 	drm_client_framebuffer_create from drm_fbdev_dma_helper_fb_probe+0x84/0x23c
>> 	drm_fbdev_dma_helper_fb_probe from __drm_fb_helper_initial_config_and_unlock+0x2e4/0x4f8
>> 	__drm_fb_helper_initial_config_and_unlock from drm_fbdev_dma_client_hotplug+0x74/0xb8
>> 	drm_fbdev_dma_client_hotplug from drm_client_register+0x5c/0x98
>> 	drm_client_register from aspeed_gfx_probe+0x278/0x3c0
>> 	aspeed_gfx_probe from platform_probe+0x60/0xb8
>> 	platform_probe from really_probe+0xd4/0x3b4
>> 	really_probe from __driver_probe_device+0x90/0x1dc
>> 	__driver_probe_device from driver_probe_device+0x38/0xd0
>> 	driver_probe_device from __driver_attach+0x118/0x1dc
>> 	__driver_attach from bus_for_each_dev+0x84/0xd4
>> 	bus_for_each_dev from bus_add_driver+0xec/0x1f0
>> 	bus_add_driver from driver_register+0x84/0x11c
>> 	driver_register from do_one_initcall+0x84/0x1c8
>> 	do_one_initcall from kernel_init_freeable+0x1a4/0x230
>> 	kernel_init_freeable from kernel_init+0x1c/0x138
>> 	kernel_init from ret_from_fork+0x14/0x28
>> 	Exception stack(0x9f015fb0 to 0x9f015ff8)
>> 	5fa0:                                     00000000 00000000 00000000 00000000
>> 	5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
>> 	5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
>> 	---[ end trace 0000000000000000 ]---
>> 	aspeed_gfx 1e6e6000.display: [drm] fb0: aspeed-gfx-drmd frame buffer device
>>
>> Hence, restructure the code to initialize the regions as soon as each
>> of them are added to the reserved_mem array.
>>
>> Fixes: a46cccb0ee2d ("of: reserved_mem: Restruture how the reserved memory regions are processed")
>> Signed-off-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com>
>> ---
>> v2:
>> - Fix kernel-doc for of_init_reserved_mem_node() in response to the
>>   below warning from v1:
>>   https://lore.kernel.org/all/202406181626.126X1Nbz-lkp@intel.com/
>>
>> v1:
>>   https://lore.kernel.org/all/20240617193357.3929092-1-quic_obabatun@quicinc.com/
>>
>>  drivers/of/fdt.c             |  2 +-
>>  drivers/of/of_private.h      |  2 +-
>>  drivers/of/of_reserved_mem.c | 83 +++++++++++++++++++++---------------
>>  3 files changed, 50 insertions(+), 37 deletions(-)
> Applied.
>
> In the future, do not send fixes or new versions as replies to previous 
> threads. The default behavior of b4 is to apply v6 of the series because 
> that is the 'newest' version.
>
> Rob
ack.

Thank you!
Re: [PATCH v2] of: reserved_mem: Restructure code to call reserved mem init functions earlier
Posted by Nathan Chancellor 1 year, 5 months ago
On Wed, Jun 19, 2024 at 05:10:27PM -0700, Oreoluwa Babatunde wrote:
> After all the reserved memory regions have been added to the
> reserved_mem array, a region specific initialization function is called
> on each of reserved memory regions in a loop to initialize them.
> 
> With recent changes made to allow the reserved_mem array be dynamically
> allocated, the cma reserved memory regions are not initialized until
> after the page tables are setup. This causes the warning seen in the
> dump stack below:
> 
> 	WARNING: CPU: 0 PID: 1 at mm/memory.c:2789 __apply_to_page_range+0x360/0x380
> 	CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-rc1-00007-ga46cccb0ee2d #1
> 	Hardware name: Generic DT based system
> 	Call trace:
> 	unwind_backtrace from show_stack+0x18/0x1c
> 	show_stack from dump_stack_lvl+0x54/0x68
> 	dump_stack_lvl from __warn+0x74/0x114
> 	__warn from warn_slowpath_fmt+0x13c/0x1c0
> 	warn_slowpath_fmt from __apply_to_page_range+0x360/0x380
> 	__apply_to_page_range from apply_to_page_range+0x24/0x2c
> 	apply_to_page_range from __alloc_from_contiguous+0xc4/0x158
> 	__alloc_from_contiguous from cma_allocator_alloc+0x3c/0x44
> 	cma_allocator_alloc from arch_dma_alloc+0x128/0x2b4
> 	arch_dma_alloc from dma_alloc_attrs+0x90/0x150
> 	dma_alloc_attrs from drm_gem_dma_create+0xa4/0x13c
> 	drm_gem_dma_create from drm_gem_dma_create_with_handle+0x24/0xac
> 	drm_gem_dma_create_with_handle from drm_gem_dma_dumb_create+0x44/0x50
> 	drm_gem_dma_dumb_create from drm_client_framebuffer_create+0x9c/0x164
> 	drm_client_framebuffer_create from drm_fbdev_dma_helper_fb_probe+0x84/0x23c
> 	drm_fbdev_dma_helper_fb_probe from __drm_fb_helper_initial_config_and_unlock+0x2e4/0x4f8
> 	__drm_fb_helper_initial_config_and_unlock from drm_fbdev_dma_client_hotplug+0x74/0xb8
> 	drm_fbdev_dma_client_hotplug from drm_client_register+0x5c/0x98
> 	drm_client_register from aspeed_gfx_probe+0x278/0x3c0
> 	aspeed_gfx_probe from platform_probe+0x60/0xb8
> 	platform_probe from really_probe+0xd4/0x3b4
> 	really_probe from __driver_probe_device+0x90/0x1dc
> 	__driver_probe_device from driver_probe_device+0x38/0xd0
> 	driver_probe_device from __driver_attach+0x118/0x1dc
> 	__driver_attach from bus_for_each_dev+0x84/0xd4
> 	bus_for_each_dev from bus_add_driver+0xec/0x1f0
> 	bus_add_driver from driver_register+0x84/0x11c
> 	driver_register from do_one_initcall+0x84/0x1c8
> 	do_one_initcall from kernel_init_freeable+0x1a4/0x230
> 	kernel_init_freeable from kernel_init+0x1c/0x138
> 	kernel_init from ret_from_fork+0x14/0x28
> 	Exception stack(0x9f015fb0 to 0x9f015ff8)
> 	5fa0:                                     00000000 00000000 00000000 00000000
> 	5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 	5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> 	---[ end trace 0000000000000000 ]---
> 	aspeed_gfx 1e6e6000.display: [drm] fb0: aspeed-gfx-drmd frame buffer device
> 
> Hence, restructure the code to initialize the regions as soon as each
> of them are added to the reserved_mem array.
> 
> Fixes: a46cccb0ee2d ("of: reserved_mem: Restruture how the reserved memory regions are processed")
> Signed-off-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com>

This resolves the warning that I see and I see no other warnings
introduced in any of my virtual boot tests.

Tested-by: Nathan Chancellor <nathan@kernel.org>

> ---
> v2:
> - Fix kernel-doc for of_init_reserved_mem_node() in response to the
>   below warning from v1:
>   https://lore.kernel.org/all/202406181626.126X1Nbz-lkp@intel.com/
> 
> v1:
>   https://lore.kernel.org/all/20240617193357.3929092-1-quic_obabatun@quicinc.com/
> 
>  drivers/of/fdt.c             |  2 +-
>  drivers/of/of_private.h      |  2 +-
>  drivers/of/of_reserved_mem.c | 83 +++++++++++++++++++++---------------
>  3 files changed, 50 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index 9cde2abd2fc0..ea2dff0478c7 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -1239,7 +1239,7 @@ void __init unflatten_device_tree(void)
>  	unittest_unflatten_overlay_base();
>  
>  	/* initialize the reserved memory regions */
> -	of_init_reserved_mem();
> +	of_scan_reserved_mem_reg_nodes();
>  }
>  
>  /**
> diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
> index 01b33c4b1e9f..7412aed903df 100644
> --- a/drivers/of/of_private.h
> +++ b/drivers/of/of_private.h
> @@ -181,7 +181,7 @@ static inline struct device_node *__of_get_dma_parent(const struct device_node *
>  #endif
>  
>  int fdt_scan_reserved_mem(void);
> -void of_init_reserved_mem(void);
> +void of_scan_reserved_mem_reg_nodes(void);
>  
>  bool of_fdt_device_is_available(const void *blob, unsigned long node);
>  
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> index eb54490a0a11..b31001728866 100644
> --- a/drivers/of/of_reserved_mem.c
> +++ b/drivers/of/of_reserved_mem.c
> @@ -97,6 +97,8 @@ static void __init alloc_reserved_mem_array(void)
>  	reserved_mem = new_array;
>  }
>  
> +static void __init of_init_reserved_mem_node(struct reserved_mem *rmem);
> +
>  /*
>   * of_reserved_mem_save_node() - save fdt node for second pass initialization
>   */
> @@ -115,6 +117,12 @@ static void __init of_reserved_mem_save_node(struct device_node *node, const cha
>  	rmem->base = base;
>  	rmem->size = size;
>  
> +	/*
> +	 * Run the region specific initialization function for the rmem
> +	 * node.
> +	 */
> +	of_init_reserved_mem_node(rmem);
> +
>  	reserved_mem_count++;
>  	return;
>  }
> @@ -201,6 +209,8 @@ static int __init __fdt_reserved_mem_check_root(unsigned long node)
>  	return 0;
>  }
>  
> +static void __init __rmem_check_for_overlap(void);
> +
>  /**
>   * of_scan_reserved_mem_reg_nodes() - Store info for the "reg" defined
>   * reserved memory regions.
> @@ -211,7 +221,7 @@ static int __init __fdt_reserved_mem_check_root(unsigned long node)
>   * size are all stored in the reserved_mem array by calling the
>   * of_reserved_mem_save_node() function.
>   */
> -static void __init of_scan_reserved_mem_reg_nodes(void)
> +void __init of_scan_reserved_mem_reg_nodes(void)
>  {
>  	struct device_node *node, *child;
>  	phys_addr_t base, size;
> @@ -222,6 +232,13 @@ static void __init of_scan_reserved_mem_reg_nodes(void)
>  		return;
>  	}
>  
> +	/*
> +	 * Before moving forward, allocate the exact size needed for the
> +	 * reserved_mem array and copy all previously saved contents
> +	 * into the new array if successful.
> +	 */
> +	alloc_reserved_mem_array();
> +
>  	for_each_child_of_node(node, child) {
>  		int ret = 0;
>  		const char *uname;
> @@ -246,6 +263,8 @@ static void __init of_scan_reserved_mem_reg_nodes(void)
>  		if (size)
>  			of_reserved_mem_save_node(child, uname, base, size);
>  	}
> +	/* check for overlapping reserved regions */
> +	__rmem_check_for_overlap();
>  }
>  
>  static int __init __reserved_mem_alloc_size(unsigned long node, const char *uname);
> @@ -526,44 +545,38 @@ static void __init __rmem_check_for_overlap(void)
>  }
>  
>  /**
> - * of_init_reserved_mem() - allocate and init all saved reserved memory regions
> + * of_init_reserved_mem_node() - Initialize a saved reserved memory region.
> + * @rmem: reserved_mem object of the memory region to be initialized.
> + *
> + * This function is used to call the region specific initialization
> + * function on the rmem object passed as an argument. The rmem object
> + * will contain the base address, size, node name, and device_node of
> + * the reserved memory region to be initialized.
>   */
> -void __init of_init_reserved_mem(void)
> +static void __init of_init_reserved_mem_node(struct reserved_mem *rmem)
>  {
> -	int i;
> -
> -	alloc_reserved_mem_array();
> -
> -	of_scan_reserved_mem_reg_nodes();
> +	int err;
> +	bool nomap;
> +	struct device_node *node = rmem->dev_node;
>  
> -	/* check for overlapping reserved regions */
> -	__rmem_check_for_overlap();
> +	nomap = of_property_present(node, "no-map");
>  
> -	for (i = 0; i < reserved_mem_count; i++) {
> -		struct reserved_mem *rmem = &reserved_mem[i];
> -		struct device_node *node = rmem->dev_node;
> -		int err = 0;
> -		bool nomap;
> -
> -		nomap = of_property_present(node, "no-map");
> -
> -		err = __reserved_mem_init_node(rmem);
> -		if (err != 0 && err != -ENOENT) {
> -			pr_info("node %s compatible matching fail\n", rmem->name);
> -			if (nomap)
> -				memblock_clear_nomap(rmem->base, rmem->size);
> -			else
> -				memblock_phys_free(rmem->base, rmem->size);
> -		} else {
> -			phys_addr_t end = rmem->base + rmem->size - 1;
> -			bool reusable = of_property_present(node, "reusable");
> -
> -			pr_info("%pa..%pa (%lu KiB) %s %s %s\n",
> -				&rmem->base, &end, (unsigned long)(rmem->size / SZ_1K),
> -				nomap ? "nomap" : "map",
> -				reusable ? "reusable" : "non-reusable",
> -				rmem->name ? rmem->name : "unknown");
> -		}
> +	err = __reserved_mem_init_node(rmem);
> +	if (err != 0 && err != -ENOENT) {
> +		pr_info("node %s compatible matching fail\n", rmem->name);
> +		if (nomap)
> +			memblock_clear_nomap(rmem->base, rmem->size);
> +		else
> +			memblock_phys_free(rmem->base, rmem->size);
> +	} else {
> +		phys_addr_t end = rmem->base + rmem->size - 1;
> +		bool reusable = of_property_present(node, "reusable");
> +
> +		pr_info("%pa..%pa (%lu KiB) %s %s %s\n",
> +			&rmem->base, &end, (unsigned long)(rmem->size / SZ_1K),
> +			nomap ? "nomap" : "map",
> +			reusable ? "reusable" : "non-reusable",
> +			rmem->name ? rmem->name : "unknown");
>  	}
>  }
>  
> -- 
> 2.34.1
>