Commit Graph

57 Commits

Author SHA1 Message Date
Will Deacon
129b985cc3 Merge branch 'aarch64/efi' into aarch64/for-next/core
Merge in EFI memblock changes from Ard, which form the preparatory work
for UEFI support on 32-bit ARM.
2015-12-15 10:59:03 +00:00
Will Deacon
32d6397805 arm64: mm: ensure that the zero page is visible to the page table walker
In paging_init, we allocate the zero page, memset it to zero and then
point TTBR0 to it in order to avoid speculative fetches through the
identity mapping.

In order to guarantee that the freshly zeroed page is indeed visible to
the page table walker, we need to execute a dsb instruction prior to
writing the TTBR.

Cc: <stable@vger.kernel.org> # v3.14+, for older kernels need to drop the 'ishst'
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-11 17:33:22 +00:00
Mark Rutland
e2c30ee320 arm64: mm: remove pointless PAGE_MASKing
As pgd_offset{,_k} shift the input address by PGDIR_SHIFT, the sub-page
bits will always be shifted out. There is no need to apply PAGE_MASK
before this.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-10 17:36:08 +00:00
Ard Biesheuvel
68709f4538 arm64: only consider memblocks with NOMAP cleared for linear mapping
Take the new memblock attribute MEMBLOCK_NOMAP into account when
deciding whether a certain region is or should be covered by the
kernel direct mapping.

Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-09 16:57:23 +00:00
Mark Rutland
9c4e08a302 arm64: mm: allow sections for unaligned bases
Callees of __create_mapping may decide to create section mappings if
sufficient low bits of the physical and virtual addresses they were
passed are zero. While __create_mapping rounds the virtual base address
down, it does not similarly round the physical base address down, and
hence non-zero bits in the physical address can prevent use of a section
mapping, even where a whole next-level table would be used instead.

Round down the physical base address in __create_mapping to enable all
callees to always create section mappings when such a mapping is
possible.

Cc: Laura Abbott <labbott@fedoraproject.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-01 09:47:03 +00:00
Mark Rutland
cc5d2b3b95 arm64: mm: detect bad __create_mapping uses
If a caller of __create_mapping provides a PA and VA which have
different sub-page offsets, it is not clear which offset they expect to
apply to the mapping, and is indicative of a bad caller.

In some cases, the region we wish to map may validly have a sub-page
offset in the physical and virtual addresses. For example, EFI runtime
regions have 4K granularity, yet may be mapped by a 64K page kernel. So
long as the physical and virtual offsets are the same, the region will
be mapped at the expected VAs.

Disallow calls with differing sub-page offsets, and WARN when they are
encountered, so that we can detect and fix such cases.

Cc: Laura Abbott <labbott@fedoraproject.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-01 09:47:03 +00:00
Catalin Marinas
667c27597c Revert "arm64: Mark kernel page ranges contiguous"
This reverts commit 348a65cdcb.

Incorrect page table manipulation that does not respect the ARM ARM
recommended break-before-make sequence may lead to TLB conflicts. The
contiguous PTE patch makes the system even more susceptible to such
errors by changing the mapping from a single page to a contiguous range
of pages. An additional TLB invalidation would reduce the risk window,
however, the correct fix is to switch to a temporary swapper_pg_dir.
Once the correct workaround is done, the reverted commit will be
re-applied.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Jeremy Linton <jeremy.linton@arm.com>
2015-11-26 15:42:41 +00:00
Suzuki K. Poulose
7142392dca arm64: early_alloc: Fix check for allocation failure
In early_alloc we check if the memblock_alloc failed by checking
the virtual address of the result, which will never fail. This patch
fixes it to check the actual result for failure.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-25 12:14:25 +00:00
Laura Abbott
0b2aa5b80b arm64: Fix R/O permissions in mark_rodata_ro
The permissions in mark_rodata_ro trigger a build error
with STRICT_MM_TYPECHECKS. Fix this by introducing
PAGE_KERNEL_ROX for the same reasons as PAGE_KERNEL_RO.
From Ard:

"PAGE_KERNEL_EXEC has PTE_WRITE set as well, making the range
writeable under the ARMv8.1 DBM feature, that manages the
dirty bit in hardware (writing to a page with the PTE_RDONLY
and PTE_WRITE bits both set will clear the PTE_RDONLY bit in that case)"

Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-18 12:11:36 +00:00
Ard Biesheuvel
4fee9f364b arm64: mm: use correct mapping granularity under DEBUG_RODATA
When booting a 64k pages kernel that is built with CONFIG_DEBUG_RODATA
and resides at an offset that is not a multiple of 512 MB, the rounding
that occurs in __map_memblock() and fixup_executable() results in
incorrect regions being mapped.

The following snippet from /sys/kernel/debug/kernel_page_tables shows
how, when the kernel is loaded 2 MB above the base of DRAM at 0x40000000,
the first 2 MB of memory (which may be inaccessible from non-secure EL1
or just reserved by the firmware) is inadvertently mapped into the end of
the module region.

  ---[ Modules start ]---
  0xfffffdffffe00000-0xfffffe0000000000     2M RW NX ... UXN MEM/NORMAL
  ---[ Modules end ]---
  ---[ Kernel Mapping ]---
  0xfffffe0000000000-0xfffffe0000090000   576K RW NX ... UXN MEM/NORMAL
  0xfffffe0000090000-0xfffffe0000200000  1472K ro x  ... UXN MEM/NORMAL
  0xfffffe0000200000-0xfffffe0000800000     6M ro x  ... UXN MEM/NORMAL
  0xfffffe0000800000-0xfffffe0000810000    64K ro x  ... UXN MEM/NORMAL
  0xfffffe0000810000-0xfffffe0000a00000  1984K RW NX ... UXN MEM/NORMAL
  0xfffffe0000a00000-0xfffffe00ffe00000  4084M RW NX ... UXN MEM/NORMAL

The same issue is likely to occur on 16k pages kernels whose load
address is not a multiple of 32 MB (i.e., SECTION_SIZE). So round to
SWAPPER_BLOCK_SIZE instead of SECTION_SIZE.

Fixes: da141706ae ("arm64: add better page protections to arm64")
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Cc: <stable@vger.kernel.org> # 4.0+
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-17 12:05:18 +00:00
Jisheng Zhang
9a17a21334 arm64: mmu: make split_pud and fixup_executable static
split_pud and fixup_executable are only called from within mmu.c, so
they can be declared static.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-12 15:18:14 +00:00
Ard Biesheuvel
fb226c3d7c arm64: fix R/O permissions of FDT mapping
The mapping permissions of the FDT are set to 'PAGE_KERNEL | PTE_RDONLY'
in an attempt to map the FDT as read-only. However, not only does this
break at build time under STRICT_MM_TYPECHECKS (since the two terms are
of different types in that case), it also results in both the PTE_WRITE
and PTE_RDONLY attributes to be set, which means the region is still
writable under ARMv8.1 DBM (and an attempted write will simply clear the
PT_RDONLY bit).

So instead, define PAGE_KERNEL_RO (which already has an established
meaning across architectures) and use that instead.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-09 14:26:36 +00:00
Ard Biesheuvel
b219545e96 arm64: fix STRICT_MM_TYPECHECKS issue in PTE_CONT manipulation
The new page table code that manipulates the PTE_CONT flags does so
in a way that is inconsistent with STRICT_MM_TYPECHECKS. Fix it by
using the correct combination of __pgprot() and pgprot_val().

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-09 14:23:16 +00:00
Suzuki K. Poulose
b433dce056 arm64: Handle section maps for swapper/idmap
We use section maps with 4K page size to create the swapper/idmaps.
So far we have used !64K or 4K checks to handle the case where we
use the section maps.
This patch adds a new symbol, ARM64_SWAPPER_USES_SECTION_MAPS, to
handle cases where we use section maps, instead of using the page size
symbols.

Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-19 17:52:36 +01:00
Jeremy Linton
348a65cdcb arm64: Mark kernel page ranges contiguous
With 64k pages, the next larger segment size is 512M. The linux
kernel also uses different protection flags to cover its code and data.
Because of this requirement, the vast majority of the kernel code and
data structures end up being mapped with 64k pages instead of the larger
pages common with a 4k page kernel.

Recent ARM processors support a contiguous bit in the
page tables which allows the a TLB to cover a range larger than a
single PTE if that range is mapped into physically contiguous
ram.

So, for the kernel its a good idea to set this flag. Some basic
micro benchmarks show it can significantly reduce the number of
L1 dTLB refills.

Add boot option to enable/disable CONT marking, as well as fix a
bug found by Steve Capper.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
[catalin.marinas@arm.com: remove CONFIG_ARM64_CONT_PTE altogether]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-08 18:44:14 +01:00
Will Deacon
8e63d38876 arm64: flush: use local TLB and I-cache invalidation
There are a number of places where a single CPU is running with a
private page-table and we need to perform maintenance on the TLB and
I-cache in order to ensure correctness, but do not require the operation
to be broadcast to other CPUs.

This patch adds local variants of tlb_flush_all and __flush_icache_all
to support these use-cases and updates the callers respectively.
__local_flush_icache_all also implies an isb, since it is intended to be
used synchronously.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: David Daney <david.daney@cavium.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-07 11:45:27 +01:00
Mark Rutland
c53e0baa6f arm64: mm: mark create_mapping as __init
Currently create_mapping is marked with __ref, apparently because it
refers to early_alloc. However, create_mapping has no logic to prevent
erroneous use of early_alloc after it has been freed, and is only ever
called by __init functions anyway. Thus the __ref marker is misleading
and unnecessary.

Instead, this patch marks create_mapping as __init, resulting in
warnings if it is used from a a non __init functions, and allowing its
memory to be reclaimed.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-28 11:36:09 +01:00
Mark Salter
b08d4640a3 arm64: remove dead code
Commit 68234df4ea ("arm64: kill flush_cache_all()") removed
soft_reset() from the kernel. This was the only caller of
setup_mm_for_reboot(), so remove that also.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 11:08:39 +01:00
Ard Biesheuvel
1e43ba9cd8 arm64: fix incorrect use of pgprot_t variable
This fixes a build failure under STRICT_MM_TYPECHECKS, by adding
a missing pgprot_val() around a pgport_t reference.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-30 18:03:37 +01:00
Ard Biesheuvel
61bd93ce80 arm64: use fixmap region for permanent FDT mapping
Currently, the FDT blob needs to be in the same 512 MB region as
the kernel, so that it can be mapped into the kernel virtual memory
space very early on using a minimal set of statically allocated
translation tables.

Now that we have early fixmap support, we can relax this restriction,
by moving the permanent FDT mapping to the fixmap region instead.
This way, the FDT blob may be anywhere in memory.

This also moves the vetting of the FDT to mmu.c, since the early
init code in head.S does not handle mapping of the FDT anymore.
At the same time, fix up some comments in head.S that have gone stale.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-02 16:31:33 +01:00
Linus Torvalds
714d8e7e27 arm64 updates for 4.1:
The main change here is a significant head.S rework that allows us to
 boot on machines with physical memory at a really high address without
 having to increase our mapped VA range. Other changes include:
 
 - AES performance boost for Cortex-A57
 - AArch32 (compat) userspace with 64k pages
 - Cortex-A53 erratum workaround for #845719
 - defconfig updates (new platforms, PCI, ...)
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "Here are the core arm64 updates for 4.1.

  Highlights include a significant rework to head.S (allowing us to boot
  on machines with physical memory at a really high address), an AES
  performance boost on Cortex-A57 and the ability to run a 32-bit
  userspace with 64k pages (although this requires said userspace to be
  built with a recent binutils).

  The head.S rework spilt over into KVM, so there are some changes under
  arch/arm/ which have been acked by Marc Zyngier (KVM co-maintainer).
  In particular, the linker script changes caused us some issues in
  -next, so there are a few merge commits where we had to apply fixes on
  top of a stable branch.

  Other changes include:

   - AES performance boost for Cortex-A57
   - AArch32 (compat) userspace with 64k pages
   - Cortex-A53 erratum workaround for #845719
   - defconfig updates (new platforms, PCI, ...)"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (39 commits)
  arm64: fix midr range for Cortex-A57 erratum 832075
  arm64: errata: add workaround for cortex-a53 erratum #845719
  arm64: Use bool function return values of true/false not 1/0
  arm64: defconfig: updates for 4.1
  arm64: Extract feature parsing code from cpu_errata.c
  arm64: alternative: Allow immediate branch as alternative instruction
  arm64: insn: Add aarch64_insn_decode_immediate
  ARM: kvm: round HYP section to page size instead of log2 upper bound
  ARM: kvm: assert on HYP section boundaries not actual code size
  arm64: head.S: ensure idmap_t0sz is visible
  arm64: pmu: add support for interrupt-affinity property
  dt: pmu: extend ARM PMU binding to allow for explicit interrupt affinity
  arm64: head.S: ensure visibility of page tables
  arm64: KVM: use ID map with increased VA range if required
  arm64: mm: increase VA range of identity map
  ARM: kvm: implement replacement for ld's LOG2CEIL()
  arm64: proc: remove unused cpu_get_pgd macro
  arm64: enforce x1|x2|x3 == 0 upon kernel entry as per boot protocol
  arm64: remove __calc_phys_offset
  arm64: merge __enable_mmu and __turn_mmu_on
  ...
2015-04-16 13:58:29 -05:00
Kirill A. Shutemov
9f25e6ad58 arm64: expose number of page table levels on Kconfig level
We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

ARM64_PGTABLE_LEVELS is renamed to PGTABLE_LEVELS and defined before
sourcing init/Kconfig: arch/Kconfig will define default value and it's
sourced from init/Kconfig.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:49:01 -07:00
Ard Biesheuvel
dd006da216 arm64: mm: increase VA range of identity map
The page size and the number of translation levels, and hence the supported
virtual address range, are build-time configurables on arm64 whose optimal
values are use case dependent. However, in the current implementation, if
the system's RAM is located at a very high offset, the virtual address range
needs to reflect that merely because the identity mapping, which is only used
to enable or disable the MMU, requires the extended virtual range to map the
physical memory at an equal virtual offset.

This patch relaxes that requirement, by increasing the number of translation
levels for the identity mapping only, and only when actually needed, i.e.,
when system RAM's offset is found to be out of reach at runtime.

Tested-by: Laura Abbott <lauraa@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-23 11:35:29 +00:00
Mark Rutland
b63dbef93f arm64: fixmap: check idx is definitely valid
Fixmap indices are in the interval (FIX_HOLE, __end_of_fixed_addresses),
but in __set_fixmap we only check idx <= __end_of_fixed_addresses, and
therefore indices <= FIX_HOLE are erroneously accepted. If called with
such an idx, __set_fixmap may corrupt page tables outside of the fixmap
region.

This patch ensures that we validate the idx against both endpoints of
the interval.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-19 10:43:57 +00:00
Catalin Marinas
41089357e1 arm64: Fix section mismatch on alloc_init_p[mu]d()
Commit 523d6e9fae (arm64:mm: free the useless initial page table)
introduced a BUG_ON checking for the allocation type but it was
referring the early_alloc() function in the __init section. This patch
changes the check to slab_is_available() and also relaxes the BUG to a
WARN_ON_ONCE.

Reported-by: Will Deacon <will.deacon@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-29 17:33:35 +00:00
Mark Rutland
a1c76574f3 arm64: mm: use *_sect to check for section maps
The {pgd,pud,pmd}_bad family of macros have slightly fuzzy
cross-architecture semantics, and seem to imply a populated entry that
is not a next-level table, rather than a particular type of entry (e.g.
a section map).

In arm64 code, for those cases where we care about whether an entry is a
section mapping, we can instead use the {pud,pmd}_sect macros to
explicitly check for this case. This helps to document precisely what we
care about, making the code easier to read, and allows for future
relaxation of the *_bad macros to check for other "bad" entries.

To that end this patch updates the table dumping and initial table setup
to check for section mappings with {pud,pmd}_sect, and adds/restores
BUG_ON(*_bad((*p)) checks after we've handled the *_sect and *_none
cases so as to catch remaining "bad" cases.

In the fault handling code, show_pte is left with *_bad checks as it
only cares about whether it can walk the next level table, and this path
is used for both kernel and userspace fault handling. The former case
will be followed by a die() where we'll report the address that
triggered the fault, which can be useful context for debugging.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Steve Capper <steve.capper@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-28 14:27:43 +00:00
Mark Rutland
a3bba370c2 arm64: drop unnecessary cache+tlb maintenance
In paging_init, we call flush_cache_all, but this is backed by Set/Way
operations which may not achieve anything in the presence of cache line
migration and/or system caches. If the caches are already in an
inconsistent state at this point, there is nothing we can do (short of
flushing the entire physical address space by VA) to empty architected
and system caches. As such, flush_cache_all only serves to mask other
potential bugs. Hence, this patch removes the boot-time call to
flush_cache_all.

Immediately after the cache maintenance we flush the TLBs, but this is
also unnecessary. Before enabling the MMU, the TLBs are invalidated, and
thus are initially clean. When changing the contents of active tables
(e.g. in fixup_executable() for DEBUG_RODATA) we perform the required
TLB maintenance following the update, and therefore no additional
maintenance is required to ensure the new table entries are in effect.
Since activating the MMU we will not have modified system register
fields permitted to be cached in a TLB, and therefore do not need
maintenance for any cached system register fields. Hence, the TLB flush
is unnecessary.

Shortly after the unnecessary TLB flush, we update TTBR0 to point to an
empty zero page rather than the idmap, and flush the TLBs. This
maintenance is necessary to remove the global idmap entries from the
TLBs (as they would conflict with userspace mappings), and is retained.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Steve Capper <steve.capper@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-28 14:26:48 +00:00
zhichang.yuan
523d6e9fae arm64:mm: free the useless initial page table
For 64K page system, after mapping a PMD section, the corresponding initial
page table is not needed any more. That page can be freed.

Signed-off-by: Zhichang Yuan <zhichang.yuan@linaro.org>
[catalin.marinas@arm.com: added BUG_ON() to catch late memblock freeing]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-28 12:07:28 +00:00
Ard Biesheuvel
60305db988 arm64/efi: move virtmap init to early initcall
Now that the create_mapping() code in mm/mmu.c is able to support
setting up kernel page tables at initcall time, we can move the whole
virtmap creation to arm64_enable_runtime_services() instead of having
a distinct stage during early boot. This also allows us to drop the
arm64-specific EFI_VIRTMAP flag.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-22 14:59:25 +00:00
Laura Abbott
da141706ae arm64: add better page protections to arm64
Add page protections for arm64 similar to those in arm.
This is for security reasons to prevent certain classes
of exploits. The current method:

- Map all memory as either RWX or RW. We round to the nearest
  section to avoid creating page tables before everything is mapped
- Once everything is mapped, if either end of the RWX section should
  not be X, we split the PMD and remap as necessary
- When initmem is to be freed, we change the permissions back to
  RW (using stop machine if necessary to flush the TLB)
- If CONFIG_DEBUG_RODATA is set, the read only sections are set
  read only.

Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-22 14:54:29 +00:00
Mark Rutland
26a945caf3 arm64: remove broken cachepolicy code
The cachepolicy kernel parameter was intended to aid in the debugging of
coherency issues, but it is fundamentally broken for several reasons:

 * On SMP platforms, only the boot CPU's tcr_el1 is altered. Secondary
   CPUs may therefore use differ w.r.t. the attributes they apply to
   MT_NORMAL memory, resulting in a loss of coherency.

 * The cache maintenance using flush_dcache_all (based on Set/Way
   operations) is not guaranteed to empty a given CPU's cache hierarchy
   while said CPU has caches enabled, it cannot empty the caches of
   other coherent PEs, nor is it guaranteed to flush data to the PoC
   even when caches are disabled.

 * The TLBs are not invalidated around the modification of MAIR_EL1 and
   TCR_EL1, as required by the architecture (as both are permitted to be
   cached in a TLB). This may result in CPUs using attributes other than
   those expected for some memory accesses, resulting in a loss of
   coherency.

 * Exclusive accesses are not architecturally guaranteed to function as
   expected on memory marked as Write-Through or Non-Cacheable. Thus
   changing the attributes of MT_NORMAL away from the (architecurally
   safe) defaults may cause uses of these instructions (e.g. atomics) to
   behave erratically.

Given this, the cachepolicy code cannot be used for debugging purposes
as it alone is likely to cause coherency issues. This patch removes the
broken cachepolicy code.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-13 22:50:47 +00:00
Ard Biesheuvel
9679be1031 arm64/efi: remove idmap manipulations from UEFI code
Now that we have moved the call to SetVirtualAddressMap() to the stub,
UEFI has no use for the ID map, so we can drop the code that installs
ID mappings for UEFI memory regions.

Acked-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2015-01-12 16:29:32 +00:00
Ard Biesheuvel
8ce837cee8 arm64/mm: add create_pgd_mapping() to create private page tables
For UEFI, we need to install the memory mappings used for Runtime Services
in a dedicated set of page tables. Add create_pgd_mapping(), which allows
us to allocate and install those page table entries early.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2015-01-12 08:16:52 +00:00
Ard Biesheuvel
e1e1fddae7 arm64/mm: add explicit struct_mm argument to __create_mapping()
Currently, swapper_pg_dir and idmap_pg_dir share the init_mm mm_struct
instance. To allow the introduction of other pg_dir instances, for instance,
for UEFI's mapping of Runtime Services, make the struct_mm instance an
explicit argument that gets passed down to the pmd and pte instantiation
functions. Note that the consumers (pmd_populate/pgd_populate) of the
mm_struct argument don't actually inspect it, but let's fix it for
correctness' sake.

Acked-by: Steve Capper <steve.capper@linaro.org>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2015-01-12 08:16:42 +00:00
Laura Abbott
af86e5974d arm64: Factor out fixmap initialization from ioremap
The fixmap API was originally added for arm64 for
early_ioremap purposes. It can be used for other purposes too
so move the initialization from ioremap to somewhere more
generic. This makes it obvious where the fixmap is being set
up and allows for a cleaner implementation of __set_fixmap.

Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-25 15:56:45 +00:00
Min-Hua Chen
4ee2098081 arm64: fix data type for physical address
Use phys_addr_t for physical address in alloc_init_pud. Although
phys_addr_t and unsigned long are 64 bit in arm64, it is better
to use phys_addr_t to describe physical addresses.

Signed-off-by: Min-Hua Chen <orca.chen@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-06 17:25:27 +00:00
Catalin Marinas
3dec0fe48a arm64: Fix memblock current_limit with 64K pages and 48-bit VA
With 48-bit VA space, the 64K page configuration uses 3 levels instead
of 2 and PUD_SIZE != PMD_SIZE. Since with 64K pages we only cover
PMD_SIZE with the initial swapper_pg_dir populated in head.S, the
memblock current_limit needs to be set accordingly in map_mem() to avoid
allocating unmapped memory. The memblock current_limit is progressively
increased as more blocks are mapped.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-10-24 18:16:47 +01:00
Mark Charlebois
fe184066ab arm64: LLVMLinux: Fix inline arm64 assembly for use with clang
Remove '#' from immediate parameter in AARCH64 inline assembly in mmu.

This code now works with both gcc and clang.

Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-09-15 17:56:39 +01:00
Jungseok Lee
c79b954bf6 arm64: mm: Implement 4 levels of translation tables
This patch implements 4 levels of translation tables since 3 levels
of page tables with 4KB pages cannot support 40-bit physical address
space described in [1] due to the following issue.

It is a restriction that kernel logical memory map with 4KB + 3 levels
(0xffffffc000000000-0xffffffffffffffff) cannot cover RAM region from
544GB to 1024GB in [1]. Specifically, ARM64 kernel fails to create
mapping for this region in map_mem function since __phys_to_virt for
this region reaches to address overflow.

If SoC design follows the document, [1], over 32GB RAM would be placed
from 544GB. Even 64GB system is supposed to use the region from 544GB
to 576GB for only 32GB RAM. Naturally, it would reach to enable 4 levels
of page tables to avoid hacking __virt_to_phys and __phys_to_virt.

However, it is recommended 4 levels of page table should be only enabled
if memory map is too sparse or there is about 512GB RAM.

References
----------
[1]: Principles of ARM Memory Maps, White Paper, Issue C

Signed-off-by: Jungseok Lee <jays.lee@samsung.com>
Reviewed-by: Sungjinn Chung <sungjinn.chung@samsung.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Steve Capper <steve.capper@linaro.org>
[catalin.marinas@arm.com: MEMBLOCK_INITIAL_LIMIT removed, same as PUD_SIZE]
[catalin.marinas@arm.com: early_ioremap_init() updated for 4 levels]
[catalin.marinas@arm.com: 48-bit VA depends on BROKEN until KVM is fixed]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Jungseok Lee <jungseoklee85@gmail.com>
2014-07-23 15:27:40 +01:00
Linus Torvalds
cc07aabc53 - Optimised assembly string/memory routines (based on the AArch64 Cortex
Strings library contributed to glibc but re-licensed under GPLv2)
 - Optimised crypto algorithms making use of the ARMv8 crypto extensions
   (together with kernel API for using FPSIMD instructions in interrupt
   context)
 - Ftrace support
 - CPU topology parsing from DT
 - ESR_EL1 (Exception Syndrome Register) exposed to user space signal
   handlers for SIGSEGV/SIGBUS (useful to emulation tools like Qemu)
 - 1GB section linear mapping if applicable
 - Barriers usage clean-up
 - Default pgprot clean-up
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into next

Pull arm64 updates from Catalin Marinas:
 - Optimised assembly string/memory routines (based on the AArch64
   Cortex Strings library contributed to glibc but re-licensed under
   GPLv2)
 - Optimised crypto algorithms making use of the ARMv8 crypto extensions
   (together with kernel API for using FPSIMD instructions in interrupt
   context)
 - Ftrace support
 - CPU topology parsing from DT
 - ESR_EL1 (Exception Syndrome Register) exposed to user space signal
   handlers for SIGSEGV/SIGBUS (useful to emulation tools like Qemu)
 - 1GB section linear mapping if applicable
 - Barriers usage clean-up
 - Default pgprot clean-up

Conflicts as per Catalin.

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (57 commits)
  arm64: kernel: initialize broadcast hrtimer based clock event device
  arm64: ftrace: Add system call tracepoint
  arm64: ftrace: Add CALLER_ADDRx macros
  arm64: ftrace: Add dynamic ftrace support
  arm64: Add ftrace support
  ftrace: Add arm64 support to recordmcount
  arm64: Add 'notrace' attribute to unwind_frame() for ftrace
  arm64: add __ASSEMBLY__ in asm/insn.h
  arm64: Fix linker script entry point
  arm64: lib: Implement optimized string length routines
  arm64: lib: Implement optimized string compare routines
  arm64: lib: Implement optimized memcmp routine
  arm64: lib: Implement optimized memset routine
  arm64: lib: Implement optimized memmove routine
  arm64: lib: Implement optimized memcpy routine
  arm64: defconfig: enable a few more common/useful options in defconfig
  ftrace: Make CALLER_ADDRx macros more generic
  arm64: Fix deadlock scenario with smp_send_stop()
  arm64: Fix machine_shutdown() definition
  arm64: Support arch_irq_work_raise() via self IPIs
  ...
2014-06-06 10:43:28 -07:00
Linus Torvalds
c3c55a0720 Merge branch 'arm64-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull ARM64 EFI update from Peter Anvin:
 "By agreement with the ARM64 EFI maintainers, we have agreed to make
  -tip the upstream for all EFI patches.  That is why this patchset
  comes from me :)

  This patchset enables EFI stub support for ARM64, like we already have
  on x86"

* 'arm64-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arm64: efi: only attempt efi map setup if booting via EFI
  efi/arm64: ignore dtb= when UEFI SecureBoot is enabled
  doc: arm64: add description of EFI stub support
  arm64: efi: add EFI stub
  doc: arm: add UEFI support documentation
  arm64: add EFI runtime services
  efi: Add shared FDT related functions for ARM/ARM64
  arm64: Add function to create identity mappings
  efi: add helper function to get UEFI params from FDT
  doc: efi-stub.txt updates for ARM
  lib: add fdt_empty_tree.c
2014-06-05 13:15:32 -07:00
Steve Capper
206a2a73a6 arm64: mm: Create gigabyte kernel logical mappings where possible
We have the capability to map 1GB level 1 blocks when using a 4K
granule.

This patch adjusts the create_mapping logic s.t. when mapping physical
memory on boot, we attempt to use a 1GB block if both the VA and PA
start and end are 1GB aligned. This both reduces the levels of lookup
required to resolve a kernel logical address, as well as reduces TLB
pressure on cores that support 1GB TLB entries.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Tested-by: Jungseok Lee <jays.lee@samsung.com>
[catalin.marinas@arm.com: s/prot_sect_kernel/PROT_SECT_NORMAL_EXEC/]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-05-09 16:10:58 +01:00
Catalin Marinas
a501e32430 arm64: Clean up the default pgprot setting
The primary aim of this patchset is to remove the pgprot_default and
prot_sect_default global variables and rely strictly on predefined
values. The original goal was to be able to run SMP kernels on UP
hardware by not setting the Shareability bit. However, it is unlikely to
see UP ARMv8 hardware and even if we do, the Shareability bit is no
longer assumed to disable cacheable accesses.

A side effect is that the device mappings now have the Shareability
attribute set. The hardware, however, should ignore it since Device
accesses are always Outer Shareable.

Following the removal of the two global variables, there is some PROT_*
macro reshuffling and cleanup, including the __PAGE_* macros (replaced
by PAGE_*).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
2014-05-09 15:53:37 +01:00
Dave Anderson
da6e4cb67c arm64: Fix for the arm64 kern_addr_valid() function
Fix for the arm64 kern_addr_valid() function to recognize
virtual addresses in the kernel logical memory map.  The
function fails as written because it does not check whether
the addresses in that region are mapped at the pmd level to
2MB or 512MB pages, continues the page table walk to the
pte level, and issues a garbage value to pfn_valid().

Tested on 4K-page and 64K-page kernels.

Signed-off-by: Dave Anderson <anderson@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-05-03 22:20:29 +01:00
Mark Salter
d7ecbddf4c arm64: Add function to create identity mappings
At boot time, before switching to a virtual UEFI memory map, firmware
expects UEFI memory and IO regions to be identity mapped whenever
kernel makes runtime services calls. The existing early boot code
creates an identity map of kernel text/data but this is not sufficient
for UEFI. This patch adds a create_id_mapping() function which reuses
the core code of the existing create_mapping().

Signed-off-by: Mark Salter <msalter@redhat.com>
[ Fixed error message formatting (%pa). ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-04-30 19:49:52 +01:00
Mark Salter
bf4b558eba arm64: add early_ioremap support
Add support for early IO or memory mappings which are needed before the
normal ioremap() is usable.  This also adds fixmap support for permanent
fixed mappings such as that used by the earlyprintk device register
region.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:15 -07:00
Mark Salter
0bf757c73d arm64: initialize pgprot info earlier in boot
Presently, paging_init() calls init_mem_pgprot() to initialize pgprot
values used by macros such as PAGE_KERNEL, PAGE_KERNEL_EXEC, etc.

The new fixmap and early_ioremap support also needs to use these macros
before paging_init() is called.  This patch moves the init_mem_pgprot()
call out of paging_init() and into setup_arch() so that pgprot_default
gets initialized in time for fixmap and early_ioremap.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:15 -07:00
Catalin Marinas
a55f9929a9 arm64: Invalidate the TLB when replacing pmd entries during boot
With the 64K page size configuration, __create_page_tables in head.S
maps enough memory to get started but using 64K pages rather than 512M
sections with a single pgd/pud/pmd entry pointing to a pte table.
create_mapping() may override the pgd/pud/pmd table entry with a block
(section) one if the RAM size is more than 512MB and aligned correctly.
For the end of this block to be accessible, the old TLB entry must be
invalidated.

Cc: <stable@vger.kernel.org>
Reported-by: Mark Salter <msalter@redhat.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05 10:30:51 +00:00
Catalin Marinas
e25208f77c arm64: Fix mapping of memory banks not ending on a PMD_SIZE boundary
The map_mem() function limits the current memblock limit to PGDIR_SIZE
(the initial swapper_pg_dir mapping) to avoid create_mapping()
allocating memory from unmapped areas. However, if the first block is
within PGDIR_SIZE and not ending on a PMD_SIZE boundary, when 4K page
configuration is enabled, create_mapping() will try to allocate a pte
page. Such page may be returned by memblock_alloc() from the end of such
bank (or any subsequent bank within PGDIR_SIZE) which is not mapped yet.

The patch limits the current memblock limit to the aligned end of the
first bank and gradually increases it as more memory is mapped. It also
ensures that the start of the first bank is aligned to PMD_SIZE to avoid
pte page allocation for this mapping.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: "Leizhen (ThunderTown, Euler)" <thunder.leizhen@huawei.com>
Tested-by: "Leizhen (ThunderTown, Euler)" <thunder.leizhen@huawei.com>
2013-08-28 10:47:00 +01:00
Catalin Marinas
aa729dccb5 Merge branch 'for-next/hugepages' of git://git.linaro.org/people/stevecapper/linux into upstream-hugepages
* 'for-next/hugepages' of git://git.linaro.org/people/stevecapper/linux:
  ARM64: mm: THP support.
  ARM64: mm: Raise MAX_ORDER for 64KB pages and THP.
  ARM64: mm: HugeTLB support.
  ARM64: mm: Move PTE_PROT_NONE bit.
  ARM64: mm: Make PAGE_NONE pages read only and no-execute.
  ARM64: mm: Restore memblock limit when map_mem finished.
  mm: thp: Correct the HPAGE_PMD_ORDER check.
  x86: mm: Remove general hugetlb code from x86.
  mm: hugetlb: Copy general hugetlb code from x86 to mm.
  x86: mm: Remove x86 version of huge_pmd_share.
  mm: hugetlb: Copy huge_pmd_share from x86 to mm.

Conflicts:
	arch/arm64/Kconfig
	arch/arm64/include/asm/pgtable-hwdef.h
	arch/arm64/include/asm/pgtable.h
2013-07-01 11:20:58 +01:00