From 6657fca06e3ffab8d0b3f9d8b397f5ee498952d7 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Wed, 14 Feb 2018 21:25:42 +0300 Subject: x86/mm: Allow to boot without LA57 if CONFIG_X86_5LEVEL=y All pieces of the puzzle are in place and we can now allow to boot with CONFIG_X86_5LEVEL=y on a machine without LA57 support. Kernel will detect that LA57 is missing and fold p4d at runtime. Update the documentation and the Kconfig option description to reflect the change. Signed-off-by: Kirill A. Shutemov Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dan Williams Cc: Dave Hansen Cc: David Woodhouse Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180214182542.69302-10-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar --- Documentation/x86/x86_64/5level-paging.txt | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'Documentation') diff --git a/Documentation/x86/x86_64/5level-paging.txt b/Documentation/x86/x86_64/5level-paging.txt index 087251a0d99c..2432a5ef86d9 100644 --- a/Documentation/x86/x86_64/5level-paging.txt +++ b/Documentation/x86/x86_64/5level-paging.txt @@ -20,12 +20,9 @@ Documentation/x86/x86_64/mm.txt CONFIG_X86_5LEVEL=y enables the feature. -So far, a kernel compiled with the option enabled will be able to boot -only on machines that supports the feature -- see for 'la57' flag in -/proc/cpuinfo. - -The plan is to implement boot-time switching between 4- and 5-level paging -in the future. +Kernel with CONFIG_X86_5LEVEL=y still able to boot on 4-level hardware. +In this case additional page table level -- p4d -- will be folded at +runtime. == User-space and large virtual address space == -- cgit v1.2.3 From ef61f8a340fd6d49df6b367785743febc47320c1 Mon Sep 17 00:00:00 2001 From: "Jan H. Schönherr" Date: Sat, 3 Feb 2018 00:10:20 +0100 Subject: x86/boot/e820: Implement a range manipulation operator MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a more versatile memmap= operator, which -- in addition to all the things that were possible before -- allows you to: - redeclare existing ranges -- before, you were limited to adding ranges; - drop any range -- like a mem= for any location; - use any e820 memory type -- not just some predefined ones. The syntax is: memmap=%-+ Size and offset work as usual. The "-" and "+" are optional and their existence determine the behavior: The command works on the specified range of memory limited to type (if specified). This memory is then configured to show up as . If is not specified, the memory is removed from the e820 map. Signed-off-by: Jan H. Schönherr Cc: Andy Lutomirski Cc: Andy Shevchenko Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180202231020.15608-1-jschoenh@amazon.de Signed-off-by: Ingo Molnar --- Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++ arch/x86/kernel/e820.c | 18 ++++++++++++++++++ 2 files changed, 27 insertions(+) (limited to 'Documentation') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 1d1d53f85ddd..5529fa82700b 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2237,6 +2237,15 @@ The memory region may be marked as e820 type 12 (0xc) and is NVDIMM or ADR memory. + memmap=%-+ + [KNL,ACPI] Convert memory within the specified region + from to . If "-" is left + out, the whole region will be marked as , + even if previously unavailable. If "+" is left + out, matching memory will be removed. Types are + specified as e820 types, e.g., 1 = RAM, 2 = reserved, + 3 = ACPI, 12 = PRAM. + memory_corruption_check=0/1 [X86] Some BIOSes seem to corrupt the first 64k of memory when doing things like suspend/resume. diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 71c11ad5643e..6a2cb1442e05 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -924,6 +924,24 @@ static int __init parse_memmap_one(char *p) } else if (*p == '!') { start_at = memparse(p+1, &p); e820__range_add(start_at, mem_size, E820_TYPE_PRAM); + } else if (*p == '%') { + enum e820_type from = 0, to = 0; + + start_at = memparse(p + 1, &p); + if (*p == '-') + from = simple_strtoull(p + 1, &p, 0); + if (*p == '+') + to = simple_strtoull(p + 1, &p, 0); + if (*p != '\0') + return -EINVAL; + if (from && to) + e820__range_update(start_at, mem_size, from, to); + else if (to) + e820__range_add(start_at, mem_size, to); + else if (from) + e820__range_remove(start_at, mem_size, from, 1); + else + e820__range_remove(start_at, mem_size, 0, 0); } else { e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1); } -- cgit v1.2.3