mem_init() currently relies on knowing the boundaries of the crashkernel
reservation to map such region with page granularity for later
unmapping via set_memory_valid(..., 0). If the crashkernel reservation
is deferred, such boundaries are not known when the linear mapping is
created. Simply parse the command line for "crashkernel" and, if found,
create the linear map with NO_BLOCK_MAPPINGS.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Acked-by: NJames Morse <james.morse@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20201119175556.18681-1-catalin.marinas@arm.comSigned-off-by: NCatalin Marinas <catalin.marinas@arm.com>

When section mappings are enabled, we allocate vmemmap pages from
physically continuous memory of size PMD_SIZE using
vmemmap_alloc_block_buf(). Section mappings are good to reduce TLB
pressure. But when system is highly fragmented and memory blocks are
being hot-added at runtime, its possible that such physically continuous
memory allocations can fail. Rather than failing the memory hot-add
procedure, add a fallback option to allocate vmemmap pages from
discontinuous pages using vmemmap_populate_basepages().
Signed-off-by: NSudarshan Rajagopalan <sudaraja@codeaurora.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Reviewed-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Acked-by: NWill Deacon <will@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/d6c06f2ef39bbe6c715b2f6db76eb16155fdcee6.1602722808.git.sudaraja@codeaurora.orgSigned-off-by: NCatalin Marinas <catalin.marinas@arm.com>

In a previous patch, we increased the size of the EFI PE/COFF header
to 64 KB, which resulted in the _stext symbol to appear at a fixed
offset of 64 KB into the image.

Since 64 KB is also the largest page size we support, this completely
removes the need to map the first 64 KB of the kernel image, given that
it only contains the arm64 Image header and the EFI header, neither of
which we ever access again after booting the kernel. More importantly,
we should avoid an executable mapping of non-executable and not entirely
predictable data, to deal with the unlikely event that we inadvertently
emitted something that looks like an opcode that could be used as a
gadget for speculative execution.

So let's limit the kernel mapping of .text to the [_stext, _etext)
region, which matches the view of generic code (such as kallsyms) when
it reasons about the boundaries of the kernel's .text section.
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>
Acked-by: NWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201117124729.12642-2-ardb@kernel.orgSigned-off-by: NCatalin Marinas <catalin.marinas@arm.com>

During memory hotplug process, the linear mapping should not be created for
a given memory range if that would fall outside the maximum allowed linear
range. Else it might cause memory corruption in the kernel virtual space.

Maximum linear mapping region is [PAGE_OFFSET..(PAGE_END -1)] accommodating
both its ends but excluding PAGE_END. Max physical range that can be mapped
inside this linear mapping range, must also be derived from its end points.

This ensures that arch_add_memory() validates memory hot add range for its
potential linear mapping requirements, before creating it with
__create_pgd_mapping().

Fixes: 4ab21506 ("arm64: Add memory hotplug support")
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: NArd Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/1605252614-761-1-git-send-email-anshuman.khandual@arm.comSigned-off-by: NWill Deacon <will@kernel.org>

This adds a validation function that scans the entire boot memory and makes
sure that all early memory sections are online. This check is essential for
the memory notifier to work properly, as it cannot prevent any boot memory
from offlining, if all sections are not online to begin with. Although the
boot section scanning is selectively enabled with DEBUG_VM.
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/1604896137-16644-4-git-send-email-anshuman.khandual@arm.comSigned-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This enables MEM_OFFLINE memory event handling. It will help intercept any
possible error condition such as if boot memory some how still got offlined
even after an explicit notifier failure, potentially by a future change in
generic hot plug framework. This would help detect such scenarios and help
debug further. While here, also call out the first section being attempted
for offline or got offlined.
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/1604896137-16644-3-git-send-email-anshuman.khandual@arm.comSigned-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This moves memory notifier registration earlier in the boot process from
device_initcall() to early_initcall() which will help in guarding against
potential early boot memory offline requests. Even though there should not
be any actual offlinig requests till memory block devices are initialized
with memory_dev_init() but then generic init sequence might just change in
future. Hence an early registration for the memory event notifier would be
helpful. While here, just skip the registration if CONFIG_MEMORY_HOTREMOVE
is not enabled and also call out when memory notifier registration fails.
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/1604896137-16644-2-git-send-email-anshuman.khandual@arm.comSigned-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.plSigned-off-by: NJoe Perches <joe@perches.com>
Reviewed-by: NNick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: NMiguel Ojeda <ojeda@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are several occurrences of the following pattern:

	for_each_memblock(memory, reg) {
		start = __pfn_to_phys(memblock_region_memory_base_pfn(reg);
		end = __pfn_to_phys(memblock_region_memory_end_pfn(reg));

		/* do something with start and end */
	}

Using for_each_mem_range() iterator is more appropriate in such cases and
allows simpler and cleaner code.

[akpm@linux-foundation.org: fix arch/arm/mm/pmsa-v7.c build]
[rppt@linux.ibm.com: mips: fix cavium-octeon build caused by memblock refactoring]
  Link: http://lkml.kernel.org/r/20200827124549.GD167163@linux.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Emil Renner Berthing <kernel@esmil.dk>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20200818151634.14343-13-rppt@kernel.orgSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Once user space is given access to tagged memory, the kernel must be
able to clear/save/restore tags visible to the user. This is done via
the linear mapping, therefore map it as such. The new MT_NORMAL_TAGGED
index for MAIR_EL1 is initially mapped as Normal memory and later
changed to Normal Tagged via the cpufeature infrastructure. From a
mismatched attribute aliases perspective, the Tagged memory is
considered a permission and it won't lead to undefined behaviour.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>

Fix a case of needless quotes in __section(), which Clang doesn't like.
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Acked-by: NWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200821194310.3089815-9-keescook@chromium.org

Device memory ranges when getting hot added into ZONE_DEVICE, might
require their vmemmap mapping's backing memory to be allocated from their
own range instead of consuming system memory.  This prevents large system
memory usage for potentially large device memory ranges.  Device driver
communicates this request via vmem_altmap structure.  Architecture needs
to take this request into account while creating and tearing down vemmmap
mappings.

This enables vmem_altmap support in vmemmap_populate() and vmemmap_free()
which includes vmemmap_populate_basepages() used for ARM64_16K_PAGES and
ARM64_64K_PAGES configs.
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NJia He <justin.he@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1594004178-8861-4-git-send-email-anshuman.khandual@arm.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are many instances where vmemap allocation is often switched between
regular memory and device memory just based on whether altmap is available
or not.  vmemmap_alloc_block_buf() is used in various platforms to
allocate vmemmap mappings.  Lets also enable it to handle altmap based
device memory allocation along with existing regular memory allocations.
This will help in avoiding the altmap based allocation switch in many
places.  To summarize there are two different methods to call
vmemmap_alloc_block_buf().

vmemmap_alloc_block_buf(size, node, NULL)   /* Allocate from system RAM */
vmemmap_alloc_block_buf(size, node, altmap) /* Allocate from altmap */

This converts altmap_alloc_block_buf() into a static function, drops it's
entry from the header and updates Documentation/vm/memory-model.rst.
Suggested-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NJia He <justin.he@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Will Deacon <will@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yu Zhao <yuzhao@google.com>
Link: http://lkml.kernel.org/r/1594004178-8861-3-git-send-email-anshuman.khandual@arm.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "arm64: Enable vmemmap mapping from device memory", v4.

This series enables vmemmap backing memory allocation from device memory
ranges on arm64.  But before that, it enables vmemmap_populate_basepages()
and vmemmap_alloc_block_buf() to accommodate struct vmem_altmap based
alocation requests.

This patch (of 3):

vmemmap_populate_basepages() is used across platforms to allocate backing
memory for vmemmap mapping.  This is used as a standard default choice or
as a fallback when intended huge pages allocation fails.  This just
creates entire vmemmap mapping with base pages (PAGE_SIZE).

On arm64 platforms, vmemmap_populate_basepages() is called instead of the
platform specific vmemmap_populate() when ARM64_SWAPPER_USES_SECTION_MAPS
is not enabled as in case for ARM64_16K_PAGES and ARM64_64K_PAGES configs.

At present vmemmap_populate_basepages() does not support allocating from
driver defined struct vmem_altmap while trying to create vmemmap mapping
for a device memory range.  It prevents ARM64_16K_PAGES and
ARM64_64K_PAGES configs on arm64 from supporting device memory with
vmemap_altmap request.

This enables vmem_altmap support in vmemmap_populate_basepages() unlocking
device memory allocation for vmemap mapping on arm64 platforms with 16K or
64K base page configs.

Each architecture should evaluate and decide on subscribing device memory
based base page allocation through vmemmap_populate_basepages().  Hence
lets keep it disabled on all archs in order to preserve the existing
semantics.  A subsequent patch enables it on arm64.
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NJia He <justin.he@arm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NWill Deacon <will@kernel.org>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Link: http://lkml.kernel.org/r/1594004178-8861-1-git-send-email-anshuman.khandual@arm.com
Link: http://lkml.kernel.org/r/1594004178-8861-2-git-send-email-anshuman.khandual@arm.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm: cleanup usage of <asm/pgalloc.h>"

Most architectures have very similar versions of pXd_alloc_one() and
pXd_free_one() for intermediate levels of page table.  These patches add
generic versions of these functions in <asm-generic/pgalloc.h> and enable
use of the generic functions where appropriate.

In addition, functions declared and defined in <asm/pgalloc.h> headers are
used mostly by core mm and early mm initialization in arch and there is no
actual reason to have the <asm/pgalloc.h> included all over the place.
The first patch in this series removes unneeded includes of
<asm/pgalloc.h>

In the end it didn't work out as neatly as I hoped and moving
pXd_alloc_track() definitions to <asm-generic/pgalloc.h> would require
unnecessary changes to arches that have custom page table allocations, so
I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local
to mm/.

This patch (of 8):

In most cases <asm/pgalloc.h> header is required only for allocations of
page table memory.  Most of the .c files that include that header do not
use symbols declared in <asm/pgalloc.h> and do not require that header.

As for the other header files that used to include <asm/pgalloc.h>, it is
possible to move that include into the .c file that actually uses symbols
from <asm/pgalloc.h> and drop the include from the header file.

The process was somewhat automated using

	sed -i -E '/[<"]asm\/pgalloc\.h/d' \
                $(grep -L -w -f /tmp/xx \
                        $(git grep -E -l '[<"]asm/pgalloc\.h'))

where /tmp/xx contains all the symbols defined in
arch/*/include/asm/pgalloc.h.

[rppt@linux.ibm.com: fix powerpc warning]
Signed-off-by: NMike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NPekka Enberg <penberg@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.orgSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

KASAN sw tagging sets a random tag of 8 bits in the top byte of the pointer
returned by the memory allocating functions. So for the functions unaware
of this change, the top 8 bits of the address must be reset which is done
by the function arch_kasan_reset_tag().
Signed-off-by: NShyam Thombre <sthombre@codeaurora.org>
Link: https://lore.kernel.org/r/1591787384-5823-1-git-send-email-sthombre@codeaurora.orgSigned-off-by: NWill Deacon <will@kernel.org>

All architectures define pte_index() as

	(address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)

and all architectures define pte_offset_kernel() as an entry in the array
of PTEs indexed by the pte_index().

For the most architectures the pte_offset_kernel() implementation relies
on the availability of pmd_page_vaddr() that converts a PMD entry value to
the virtual address of the page containing PTEs array.

Let's move x86 definitions of the PTE accessors to the generic place in
<linux/pgtable.h> and then simply drop the respective definitions from the
other architectures.

The architectures that didn't provide pmd_page_vaddr() are updated to have
that defined.

The generic implementation of pte_offset_kernel() can be overridden by an
architecture and alpha makes use of this because it has special ordering
requirements for its version of pte_offset_kernel().

[rppt@linux.ibm.com: v2]
  Link: http://lkml.kernel.org/r/20200514170327.31389-11-rppt@kernel.org
[rppt@linux.ibm.com: update]
  Link: http://lkml.kernel.org/r/20200514170327.31389-12-rppt@kernel.org
[rppt@linux.ibm.com: update]
  Link: http://lkml.kernel.org/r/20200514170327.31389-13-rppt@kernel.org
[akpm@linux-foundation.org: fix x86 warning]
[sfr@canb.auug.org.au: fix powerpc build]
  Link: http://lkml.kernel.org/r/20200607153443.GB738695@linux.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-10-rppt@kernel.orgSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Implement primitives necessary for the 4th level folding, add walks of p4d
level where appropriate, replace 5level-fixup.h with pgtable-nop4d.h and
remove __ARCH_USE_5LEVEL_HACK.

[arnd@arndb.de: fix gcc-10 shift warning]
  Link: http://lkml.kernel.org/r/20200429185657.4085975-1-arnd@arndb.deSigned-off-by: NMike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: James Morse <james.morse@arm.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200414153455.21744-4-rppt@kernel.orgSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that the kernel is built with BTI annotations enable the feature by
setting the GP bit in the stage 1 translation tables.  This is done
based on the features supported by the boot CPU so that we do not need
to rewrite the translation tables.

In order to avoid potential issues on big.LITTLE systems when there are
a mix of BTI and non-BTI capable CPUs in the system when we have enabled
kernel mode BTI we change BTI to be a _STRICT_BOOT_CPU_FEATURE when we
have kernel BTI.  This will prevent any CPUs that don't support BTI
being started if the boot CPU supports BTI rather than simply not using
BTI as we do when supporting BTI only in userspace.  The main concern is
the possibility of BTYPE being preserved by a CPU that does not
implement BTI when a thread is migrated to it resulting in an incorrect
state which could generate an exception when the thread migrates back to
a CPU that does support BTI.  If we encounter practical systems which
mix BTI and non-BTI CPUs we will need to revisit this implementation.

Since we currently do not generate landing pads in the BPF JIT we only
map the base kernel text in this way.
Signed-off-by: NMark Brown <broonie@kernel.org>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200506195138.22086-5-broonie@kernel.orgSigned-off-by: NWill Deacon <will@kernel.org>

devm_memremap_pages() is currently used by the PCI P2PDMA code to create
struct page mappings for IO memory.  At present, these mappings are
created with PAGE_KERNEL which implies setting the PAT bits to be WB.
However, on x86, an mtrr register will typically override this and force
the cache type to be UC-.  In the case firmware doesn't set this
register it is effectively WB and will typically result in a machine
check exception when it's accessed.

Other arches are not currently likely to function correctly seeing they
don't have any MTRR registers to fall back on.

To solve this, provide a way to specify the pgprot value explicitly to
arch_add_memory().

Of the arches that support MEMORY_HOTPLUG: x86_64, and arm64 need a
simple change to pass the pgprot_t down to their respective functions
which set up the page tables.  For x86_32, set the page tables
explicitly using _set_memory_prot() (seeing they are already mapped).

For ia64, s390 and sh, reject anything but PAGE_KERNEL settings -- this
should be fine, for now, seeing these architectures don't support
ZONE_DEVICE.

A check in __add_pages() is also added to ensure the pgprot parameter
was set for all arches.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NDan Williams <dan.j.williams@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Badger <ebadger@gigaio.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200306170846.9333-7-logang@deltatee.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The mhp_restrictions struct really doesn't specify anything resembling a
restriction anymore so rename it to be mhp_params as it is a list of
extended parameters.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Badger <ebadger@gigaio.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200306170846.9333-3-logang@deltatee.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The arch code for hot-remove must tear down portions of the linear map and
vmemmap corresponding to memory being removed. In both cases the page
tables mapping these regions must be freed, and when sparse vmemmap is in
use the memory backing the vmemmap must also be freed.

This patch adds unmap_hotplug_range() and free_empty_tables() helpers which
can be used to tear down either region and calls it from vmemmap_free() and
___remove_pgd_mapping(). The free_mapped argument determines whether the
backing memory will be freed.

It makes two distinct passes over the kernel page table. In the first pass
with unmap_hotplug_range() it unmaps, invalidates applicable TLB cache and
frees backing memory if required (vmemmap) for each mapped leaf entry. In
the second pass with free_empty_tables() it looks for empty page table
sections whose page table page can be unmapped, TLB invalidated and freed.

While freeing intermediate level page table pages bail out if any of its
entries are still valid. This can happen for partially filled kernel page
table either from a previously attempted failed memory hot add or while
removing an address range which does not span the entire page table page
range.

The vmemmap region may share levels of table with the vmalloc region.
There can be conflicts between hot remove freeing page table pages with
a concurrent vmalloc() walking the kernel page table. This conflict can
not just be solved by taking the init_mm ptl because of existing locking
scheme in vmalloc(). So free_empty_tables() implements a floor and ceiling
method which is borrowed from user page table tear with free_pgd_range()
which skips freeing page table pages if intermediate address range is not
aligned or maximum floor-ceiling might not own the entire page table page.

Boot memory on arm64 cannot be removed. Hence this registers a new memory
hotplug notifier which prevents boot memory offlining and it's removal.

While here update arch_add_memory() to handle __add_pages() failures by
just unmapping recently added kernel linear mapping. Now enable memory hot
remove on arm64 platforms by default with ARCH_ENABLE_MEMORY_HOTREMOVE.

This implementation is overall inspired from kernel page table tear down
procedure on X86 architecture and user page table tear down method.

[Mike and Catalin added P4D page table level support]
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Now walk_page_range() can walk kernel page tables, we can switch the arm64
ptdump code over to using it, simplifying the code.

Link: http://lkml.kernel.org/r/20191218162402.45610-22-steven.price@arm.comSigned-off-by: NSteven Price <steven.price@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zong Li <zong.li@sifive.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We currently try to shrink a single zone when removing memory.  We use
the zone of the first page of the memory we are removing.  If that
memmap was never initialized (e.g., memory was never onlined), we will
read garbage and can trigger kernel BUGs (due to a stale pointer):

    BUG: unable to handle page fault for address: 000000000000353d
    #PF: supervisor write access in kernel mode
    #PF: error_code(0x0002) - not-present page
    PGD 0 P4D 0
    Oops: 0002 [#1] SMP PTI
    CPU: 1 PID: 7 Comm: kworker/u8:0 Not tainted 5.3.0-rc5-next-20190820+ #317
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.4
    Workqueue: kacpi_hotplug acpi_hotplug_work_fn
    RIP: 0010:clear_zone_contiguous+0x5/0x10
    Code: 48 89 c6 48 89 c3 e8 2a fe ff ff 48 85 c0 75 cf 5b 5d c3 c6 85 fd 05 00 00 01 5b 5d c3 0f 1f 840
    RSP: 0018:ffffad2400043c98 EFLAGS: 00010246
    RAX: 0000000000000000 RBX: 0000000200000000 RCX: 0000000000000000
    RDX: 0000000000200000 RSI: 0000000000140000 RDI: 0000000000002f40
    RBP: 0000000140000000 R08: 0000000000000000 R09: 0000000000000001
    R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000140000
    R13: 0000000000140000 R14: 0000000000002f40 R15: ffff9e3e7aff3680
    FS:  0000000000000000(0000) GS:ffff9e3e7bb00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 000000000000353d CR3: 0000000058610000 CR4: 00000000000006e0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    Call Trace:
     __remove_pages+0x4b/0x640
     arch_remove_memory+0x63/0x8d
     try_remove_memory+0xdb/0x130
     __remove_memory+0xa/0x11
     acpi_memory_device_remove+0x70/0x100
     acpi_bus_trim+0x55/0x90
     acpi_device_hotplug+0x227/0x3a0
     acpi_hotplug_work_fn+0x1a/0x30
     process_one_work+0x221/0x550
     worker_thread+0x50/0x3b0
     kthread+0x105/0x140
     ret_from_fork+0x3a/0x50
    Modules linked in:
    CR2: 000000000000353d

Instead, shrink the zones when offlining memory or when onlining failed.
Introduce and use remove_pfn_range_from_zone(() for that.  We now
properly shrink the zones, even if we have DIMMs whereby

 - Some memory blocks fall into no zone (never onlined)

 - Some memory blocks fall into multiple zones (offlined+re-onlined)

 - Multiple memory blocks that fall into different zones

Drop the zone parameter (with a potential dubious value) from
__remove_pages() and __remove_section().

Link: http://lkml.kernel.org/r/20191006085646.5768-6-david@redhat.com
Fixes: f1dd2cd1 ("mm, memory_hotplug: do not associate hotadded memory to zones until online")	[visible after d0dc12e8]
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: <stable@vger.kernel.org>	[5.0+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the
interpretation of the EFI Memory Types as "reserved for a specific
purpose".

The proposed Linux behavior for specific purpose memory is that it is
reserved for direct-access (device-dax) by default and not available for
any kernel usage, not even as an OOM fallback.  Later, through udev
scripts or another init mechanism, these device-dax claimed ranges can
be reconfigured and hot-added to the available System-RAM with a unique
node identifier. This device-dax management scheme implements "soft" in
the "soft reserved" designation by allowing some or all of the
reservation to be recovered as typical memory. This policy can be
disabled at compile-time with CONFIG_EFI_SOFT_RESERVE=n, or runtime with
efi=nosoftreserve.

For this patch, update the ARM paths that consider
EFI_CONVENTIONAL_MEMORY to optionally take the EFI_MEMORY_SP attribute
into account as a reservation indicator. Publish the soft reservation as
IORES_DESC_SOFT_RESERVED memory, similar to x86.

(Based on an original patch by Ard)
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Calculate the page-aligned end address more simply.

The local variable, "length" is unneeded.
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.

To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().

These changes were generated with the following shell script:

----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
    sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
    sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----

... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.

There should be no functional change as a result of this patch.

Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.comSigned-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NMike Rapoport <rppt@linux.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With 16K pages and 48-bit VAs, the PGD level of table has two entries,
and so the fixmap shares a PGD with the kernel image. Since commit:

  f9040773 ("arm64: move kernel image to base of vmalloc area")

... we copy the existing fixmap to the new fine-grained page tables at
the PUD level in this case. When walking to the new PUD, we forgot to
offset the PGD entry and always used the PGD entry at index 0, but this
worked as the kernel image and fixmap were in the low half of the TTBR1
address space.

As of commit:

  14c127c9 ("arm64: mm: Flip kernel VA space")

... the kernel image and fixmap are in the high half of the TTBR1
address space, and hence use the PGD at index 1, but we didn't update
the fixmap copying code to account for this.

Thus, we'll erroneously try to copy the fixmap slots into a PUD under
the PGD entry at index 0. At the point we do so this PGD entry has not
been initialised, and thus we'll try to write a value to a small offset
from physical address 0, causing a number of potential problems.

Fix this be correctly offsetting the PGD. This is split over a few steps
for legibility.

Fixes: 14c127c9 ("arm64: mm: Flip kernel VA space")
Reported-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NMarc Zyngier <maz@kernel.org>
Tested-by: NMarc Zyngier <maz@kernel.org>
Acked-by: NSteve Capper <Steve.Capper@arm.com>
Tested-by: NSteve Capper <Steve.Capper@arm.com>
Tested-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

Currently in arm64, FDT is mapped to RO before it's passed to
early_init_dt_scan(). However, there might be some codes
(eg. commit "fdt: add support for rng-seed") that need to modify FDT
during init. Map FDT to RO after early fixups are done.
Signed-off-by: NHsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: NStephen Boyd <swboyd@chromium.org>
Reviewed-by: NMike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

Prior to commit:

  14c127c9 ("arm64: mm: Flip kernel VA space")

... VA_START described the start of the TTBR1 address space for a given
VA size described by VA_BITS, where all kernel mappings began.

Since that commit, VA_START described a portion midway through the
address space, where the linear map ends and other kernel mappings
begin.

To avoid confusion, let's rename VA_START to PAGE_END, making it clear
that it's not the start of the TTBR1 address space and implying that
it's related to PAGE_OFFSET. Comments and other mnemonics are updated
accordingly, along with a typo fix in the decription of VMEMMAP_SIZE.

There should be no functional change as a result of this patch.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: NSteve Capper <steve.capper@arm.com>
Reviewed-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

Previous patches have enabled 52-bit kernel + user VAs and there is no
longer any scenario where user VA != kernel VA size.

This patch removes the, now redundant, vabits_user variable and replaces
usage with vabits_actual where appropriate.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

In order to support 52-bit kernel addresses detectable at boot time, one
needs to know the actual VA_BITS detected. A new variable vabits_actual
is introduced in this commit and employed for the KVM hypervisor layout,
KASAN, fault handling and phys-to/from-virt translation where there
would normally be compile time constants.

In order to maintain performance in phys_to_virt, another variable
physvirt_offset is introduced.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

In order to allow for a KASAN shadow that changes size at boot time, one
must fix the KASAN_SHADOW_END for both 48 & 52-bit VAs and "grow" the
start address. Also, it is highly desirable to maintain the same
function addresses in the kernel .text between VA sizes. Both of these
requirements necessitate us to flip the kernel address space halves s.t.
the direct linear map occupies the lower addresses.

This patch puts the direct linear map in the lower addresses of the
kernel VA range and everything else in the higher ranges.

We need to adjust:
 *) KASAN shadow region placement logic,
 *) KASAN_SHADOW_OFFSET computation logic,
 *) virt_to_phys, phys_to_virt checks,
 *) page table dumper.

These are all small changes, that need to take place atomically, so they
are bundled into this commit.

As part of the re-arrangement, a guard region of 2MB (to preserve
alignment for fixed map) is added after the vmemmap. Otherwise the
vmemmap could intersect with IS_ERR pointers.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

We want to improve error handling while adding memory by allowing to use
arch_remove_memory() and __remove_pages() even if
CONFIG_MEMORY_HOTREMOVE is not set to e.g., implement something like:

	arch_add_memory()
	rc = do_something();
	if (rc) {
		arch_remove_memory();
	}

We won't get rid of CONFIG_MEMORY_HOTREMOVE for now, as it will require
quite some dependencies for memory offlining.

Link: http://lkml.kernel.org/r/20190527111152.16324-7-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NPavel Tatashin <pasha.tatashin@soleen.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jun Yao <yaojun8558363@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A proper arch_remove_memory() implementation is on its way, which also
cleanly removes page tables in arch_add_memory() in case something goes
wrong.

As we want to use arch_remove_memory() in case something goes wrong
during memory hotplug after arch_add_memory() finished, let's add a
temporary hack that is sufficient enough until we get a proper
implementation that cleans up page table entries.

We will remove CONFIG_MEMORY_HOTREMOVE around this code in follow up
patches.

Link: http://lkml.kernel.org/r/20190527111152.16324-5-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jun Yao <yaojun8558363@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Finish up what commit c2febafc ("mm: convert generic code to 5-level
paging") started while levelling up P4D huge mapping support at par with
PUD and PMD.  A new arch call back arch_ioremap_p4d_supported() is added
which just maintains status quo (P4D huge map not supported) on x86,
arm64 and powerpc.

When HAVE_ARCH_HUGE_VMAP is enabled its just a simple check from the
arch about the support, hence runtime effects are minimal.

Link: http://lkml.kernel.org/r/1561699231-20991-1-git-send-email-anshuman.khandual@arm.comSigned-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The PTE allocations in arm64 are identical to the generic ones modulo the
GFP flags.

Using the generic pte_alloc_one() functions ensures that the user page
tables are allocated with __GFP_ACCOUNT set.

The arm64 definition of PGALLOC_GFP is removed and replaced with
GFP_PGTABLE_USER for p[gum]d_alloc_one() for the user page tables and
GFP_PGTABLE_KERNEL for the kernel page tables. The KVM memory cache is now
using GFP_PGTABLE_USER.

The mappings created with create_pgd_mapping() are now using
GFP_PGTABLE_KERNEL.

The conversion to the generic version of pte_free_kernel() removes the NULL
check for pte.

The pte_free() version on arm64 is identical to the generic one and
can be simply dropped.

[cai@lca.pw: fix a bogus GFP flag in pgd_alloc()]
  Link: https://lore.kernel.org/r/1559656836-24940-1-git-send-email-cai@lca.pw/
[and fix it more]
  Link: https://lore.kernel.org/linux-mm/20190617151252.GF16810@rapoport-lnx/
Link: http://lkml.kernel.org/r/1557296232-15361-5-git-send-email-rppt@linux.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.ibm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Guo Ren <ren_guo@c-sky.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Creasey <sammy@sammy.net>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAlexios Zavras <alexios.zavras@intel.com>
Reviewed-by: NAllison Randal <allison@lohutok.net>
Reviewed-by: NEnrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The config value used in the if was changed in
b433dce0, but the comment on the
corresponding end was not changed.
Signed-off-by: NOdin Ugedal <odin@ugedal.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

There are no callers for the functions which will pass unaligned physical
addresses. Hence just change these BUG_ON() checks into VM_BUG_ON() which
gets compiled out unless CONFIG_VM_DEBUG is enabled.
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>