x86/microcode: Rework microcode loading
Yeah, I know, I know, this is a huuge patch and reviewing it is hard. Sorry but this is the only way I could think of in which I can rewrite the microcode patches loading procedure without breaking (knowingly) the driver. So maybe this patch is easier to review if one looks at the files after the patch has been applied instead at the diff. Because then it becomes pretty obvious: * The BSP-loading path - load_ucode_bsp() is working independently from the AP path now and it doesn't save any pointers or patches anymore - it solely parses the builtin or initrd microcode and applies the patch. That's it. This fixes the CONFIG_RANDOMIZE_MEMORY offset fun more solidly. * The AP-loading path - load_ucode_ap() then goes and scans builtin/initrd *again* for the microcode patches but it caches them this time so that we don't have to do that scan on each AP but only once. This simplifies the code considerably. Then, when we save the microcode from the initrd/builtin, we go and add the relevant patches to our own cache. The AMD side did do that and now the Intel side does it too. So no more pointer copying and blabla, we save the microcode patches ourselves and are independent from initrd/builtin. This whole conversion gives us other benefits like unifying the initrd parsing into a single function: find_microcode_in_initrd() is used by both. The diffstat speaks for itself: 456 insertions(+), 695 deletions(-) Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161025095522.11964-12-bp@alien8.deSigned-off-by: Ingo Molnar <mingo@kernel.org>
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