On Wed, 2024-01-24 at 14:55 +0200, Kirill A. Shutemov wrote: > MADT Multiprocessor Wakeup structure version 1 brings support of CPU > offlining: BIOS provides a reset vector where the CPU has to jump to > for offlining itself. The new TEST mailbox command can be used to test > whether the CPU offlined itself which means the BIOS has control over > the CPU and can online it again via the ACPI MADT wakeup method. > > Add CPU offling support for the ACPI MADT wakeup method by implementing > custom cpu_die(), play_dead() and stop_this_cpu() SMP operations. > > CPU offlining makes is possible to hand over secondary CPUs over kexec, > not limiting the second kernel to a single CPU. > > The change conforms to the approved ACPI spec change proposal. See the > Link. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > Link: https://lore.kernel.org/all/13356251.uLZWGnKmhe@kreacher FWIW: Acked-by: Kai Huang <kai.huang@xxxxxxxxx> [...] > + > +static int __init acpi_mp_setup_reset(u64 reset_vector) > +{ > + pgd_t *pgd; > + struct x86_mapping_info info = { > + .alloc_pgt_page = alloc_pgt_page, > + .free_pgt_page = free_pgt_page, > + .page_flag = __PAGE_KERNEL_LARGE_EXEC, > + .kernpg_flag = _KERNPG_TABLE_NOENC, > + }; Nit: Reverse Christmas-tree style [...] > > -#define ACPI_MP_WAKE_COMMAND_WAKEUP 1 > +#define ACPI_MP_WAKE_COMMAND_WAKEUP 1 Nit: Is this change intended? > +#define ACPI_MP_WAKE_COMMAND_TEST 2 > _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
