On Wed, Apr 05, 2017 at 02:36:24PM +0300, Kirill A. Shutemov wrote: > On Mon, Mar 13, 2017 at 08:18:10AM +0100, Ingo Molnar wrote: > > > > * Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> wrote: > > > > > This patch adds support for 5-level paging during early boot. > > > It generalizes boot for 4- and 5-level paging on 64-bit systems with > > > compile-time switch between them. > > > > > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > > > --- > > > arch/x86/boot/compressed/head_64.S | 23 +++++++++-- > > > arch/x86/include/asm/pgtable.h | 2 +- > > > arch/x86/include/asm/pgtable_64.h | 6 ++- > > > arch/x86/include/uapi/asm/processor-flags.h | 2 + > > > arch/x86/kernel/espfix_64.c | 2 +- > > > arch/x86/kernel/head64.c | 40 +++++++++++++----- > > > arch/x86/kernel/head_64.S | 63 +++++++++++++++++++++-------- > > > > Ok, here I'd like to have a C version instead of further complicating an already > > complex assembly version... > > Just head up: I work on this. > > It's great deal of frustration (I can't really read assembly), but I'm > slowly moving forward. > > Most of logic in startup_64 in arch/x86/kernel/head_64.S is converted > to C. Dealing with secondary_startup_64 now. I'm stuck with secondary_startup_64 too. Stack breaks as soon as we switch to new page tables when onlining secondary CPUs. I don't know how to get around this. Would it be sufficient if I only convert startup_64 in arch/x86/kernel/head_64.S to C? -- Kirill A. Shutemov