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@xxxxxxxxxxx>
>> ---
>> 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@xxxxxxxxx/
>>
>> v1:
>> https://lore.kernel.org/all/20240617193357.3929092-1-quic_obabatun@xxxxxxxxxxx/
>>
>> 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!
