On Tue, Apr 16, 2024 at 09:06:35PM +0900, skseofh@xxxxxxxxx wrote: > From: Daero Lee <daero_le.lee@xxxxxxxxxxx> > > Like reserved-memory with the 'no-map' property and only 'size' property > (w/o 'reg' property), there are memory regions need to be allocated in > memblock.memory marked with the MEMBLOCK_NOMAP flag, but should not be > allocated in memblock.reserved. This still does not explain why you need such regions. As Wei Yang explained, memblock does not allocate memory from memblock.reserved. The memblock.reserved array represents memory that is in use by firmware or by early kernel allocations and cannot be freed to page allocator. If you have a region that's _NOMAP in memblock.memory and is absent in memblock.reserved it will not be mapped by the kernel page tables, but it will be considered as free memory by the core mm. Is this really what you want? > example : arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi > reserved-memory { > #address-cells = <2>; > #size-cells = <2>; > ranges; > > bman_fbpr: bman-fbpr { > compatible = "shared-dma-pool"; > size = <0 0x1000000>; > alignment = <0 0x1000000>; > no-map; > }; > > qman_fqd: qman-fqd { > compatible = "shared-dma-pool"; > size = <0 0x400000>; > alignment = <0 0x400000>; > no-map; > }; > > qman_pfdr: qman-pfdr { > compatible = "shared-dma-pool"; > size = <0 0x2000000>; > alignment = <0 0x2000000>; > no-map; > }; > }; > -- Sincerely yours, Mike.