Hi Julien, > On Sep 26, 2023, at 03:13, Julien Grall <[email protected]> wrote: > > Hi Henry, > > On 28/08/2023 02:32, Henry Wang wrote: >> Move the code related to secondary page table initialization, clear >> boot page tables and the global variable definitions of these boot >> page tables from arch/arm/mm.c to arch/arm/mmu/smpboot.c >> Drop the "static" attribute of arm32 global variable cpu0_pgtable, >> and declare it in the arm32 mm.h header, because this variable >> will be used by both arch/arm/mm.c and arch/arm/mmu/smpboot.c. > > I don't think you need to export cpu0_pgtable. You can instead replace use > with per_cpu(xen_pgtable, 0).
You mean using ``` memcpy(first, per_cpu(xen_pgtable, 0), PAGE_SIZE); ``` in the arm32 implementation of prepare_secondary_mm() in mmu/smpboot.c? That sounds good to me and I will fix in v7. > >> + */ >> +DEFINE_BOOT_PAGE_TABLE(boot_pgtable); >> +#ifdef CONFIG_ARM_64 >> +DEFINE_BOOT_PAGE_TABLE(boot_first); >> +DEFINE_BOOT_PAGE_TABLE(boot_first_id); >> +#endif >> +DEFINE_BOOT_PAGE_TABLE(boot_second_id); >> +DEFINE_BOOT_PAGE_TABLE(boot_third_id); >> +DEFINE_BOOT_PAGE_TABLE(boot_second); >> +DEFINE_BOOT_PAGE_TABLES(boot_third, XEN_NR_ENTRIES(2)); > > Strictly speaking, boot_* are also used for CPU0 but not in C code. That > said, I am ok if there are moved here. > > In the longer term, I would actually like to remove boot_*. This should > already be possible for arm64 (in fact they are not used for secondary CPU > bring-up). For arm32, it requires a bit more work. > > Anyway, that's not a request for your series. :) Let’s see if we can do that in 4.19 dev cycle then :) > >> + /* Set init_ttbr for this CPU coming up */ >> + init_ttbr = __pa(first); > > init_ttbr will only be used by smpboot.c and assembly code. So I think the > declaration needs to also be moved and the prototype moved to mmu/mm.h. Ok, will do in v7. Kind regards, Henry > > Cheers, > > -- > Julien Grall
