These objects are set during initialization, thereafter are read only.

Previously I only want to mark vdso_pages, vdso_spec, vectors_page and
cpu_ops as __read_mostly from performance point of view. Then inspired
by Kees's patch[1] to apply more __ro_after_init for arm, I think it's
better to mark them as __ro_after_init. What's more, I find some more
objects are also read only after init. So apply __ro_after_init to all
of them.

This patch also removes global vdso_pagelist and tries to clean up
vdso_spec[] assignment code.

[1] http://www.spinics.net/lists/arm-kernel/msg523188.htmlAcked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NJisheng Zhang <jszhang@marvell.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When booting an ACPI enabled kernel with 'mem=x', there is the
possibility that ACPI data regions from the firmware will lie above the
memory limit.  Ordinarily these will be removed by
memblock_enforce_memory_limit(.).

Unfortunately, this means that these regions will then be mapped by
acpi_os_ioremap(.) as device memory (instead of normal) thus unaligned
accessess will then provoke alignment faults.

In this patch we adopt memblock_mem_limit_remove_map instead, and this
preserves these ACPI data regions (marked NOMAP) thus ensuring that
these regions are not mapped as device memory.

For example, below is an alignment exception observed on ARM platform
when booting the kernel with 'acpi=on mem=8G':

  ...
  Unable to handle kernel paging request at virtual address ffff0000080521e7
  pgd = ffff000008aa0000
  [ffff0000080521e7] *pgd=000000801fffe003, *pud=000000801fffd003, *pmd=000000801fffc003, *pte=00e80083ff1c1707
  Internal error: Oops: 96000021 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc3-next-20160616+ #172
  Hardware name: AMD Overdrive/Supercharger/Default string, BIOS ROD1001A 02/09/2016
  task: ffff800001ef0000 ti: ffff800001ef8000 task.ti: ffff800001ef8000
  PC is at acpi_ns_lookup+0x520/0x734
  LR is at acpi_ns_lookup+0x4a4/0x734
  pc : [<ffff0000083b8b10>] lr : [<ffff0000083b8a94>] pstate: 60000045
  sp : ffff800001efb8b0
  x29: ffff800001efb8c0 x28: 000000000000001b
  x27: 0000000000000001 x26: 0000000000000000
  x25: ffff800001efb9e8 x24: ffff000008a10000
  x23: 0000000000000001 x22: 0000000000000001
  x21: ffff000008724000 x20: 000000000000001b
  x19: ffff0000080521e7 x18: 000000000000000d
  x17: 00000000000038ff x16: 0000000000000002
  x15: 0000000000000007 x14: 0000000000007fff
  x13: ffffff0000000000 x12: 0000000000000018
  x11: 000000001fffd200 x10: 00000000ffffff76
  x9 : 000000000000005f x8 : ffff000008725fa8
  x7 : ffff000008a8df70 x6 : ffff000008a8df70
  x5 : ffff000008a8d000 x4 : 0000000000000010
  x3 : 0000000000000010 x2 : 000000000000000c
  x1 : 0000000000000006 x0 : 0000000000000000
  ...
    acpi_ns_lookup+0x520/0x734
    acpi_ds_load1_begin_op+0x174/0x4fc
    acpi_ps_build_named_op+0xf8/0x220
    acpi_ps_create_op+0x208/0x33c
    acpi_ps_parse_loop+0x204/0x838
    acpi_ps_parse_aml+0x1bc/0x42c
    acpi_ns_one_complete_parse+0x1e8/0x22c
    acpi_ns_parse_table+0x8c/0x128
    acpi_ns_load_table+0xc0/0x1e8
    acpi_tb_load_namespace+0xf8/0x2e8
    acpi_load_tables+0x7c/0x110
    acpi_init+0x90/0x2c0
    do_one_initcall+0x38/0x12c
    kernel_init_freeable+0x148/0x1ec
    kernel_init+0x10/0xec
    ret_from_fork+0x10/0x40
  Code: b9009fbc 2a00037b 36380057 3219037b (b9400260)
  ---[ end trace 03381e5eb0a24de4 ]---
  Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

With 'efi=debug', we can see those ACPI regions loaded by firmware on
that board as:

  efi:   0x0083ff185000-0x0083ff1b4fff [Reserved           |   |  |  |  |  |  |  |   |WB|WT|WC|UC]*
  efi:   0x0083ff1b5000-0x0083ff1c2fff [ACPI Reclaim Memory|   |  |  |  |  |  |  |   |WB|WT|WC|UC]*
  efi:   0x0083ff223000-0x0083ff224fff [ACPI Memory NVS    |   |  |  |  |  |  |  |   |WB|WT|WC|UC]*

Link: http://lkml.kernel.org/r/1468475036-5852-3-git-send-email-dennis.chen@arm.comAcked-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NDennis Chen <dennis.chen@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Kaly Xin <kaly.xin@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As Kees Cook notes in the ARM counterpart of this patch [0]:

  The _etext position is defined to be the end of the kernel text code,
  and should not include any part of the data segments. This interferes
  with things that might check memory ranges and expect executable code
  up to _etext.

In particular, Kees is referring to the HARDENED_USERCOPY patch set [1],
which rejects attempts to call copy_to_user() on kernel ranges containing
executable code, but does allow access to the .rodata segment. Regardless
of whether one may or may not agree with the distinction, it makes sense
for _etext to have the same meaning across architectures.

So let's put _etext where it belongs, between .text and .rodata, and fix
up existing references to use __init_begin instead, which unlike _end_rodata
includes the exception and notes sections as well.

The _etext references in kaslr.c are left untouched, since its references
to [_stext, _etext) are meant to capture potential jump instruction targets,
and so disregarding .rodata is actually an improvement here.

[0] http://article.gmane.org/gmane.linux.kernel/2245084
[1] http://thread.gmane.org/gmane.linux.kernel.hardened.devel/2502Reported-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

We currently open-code extracting the NUMA node of a memblock region,
which requires an ifdef to cater for !CONFIG_NUMA builds where the
memblock_region::nid field does not exist.

The generic memblock_get_region_node helper is intended to cater for
this. For CONFIG_HAVE_MEMBLOCK_NODE_MAP, builds this returns reg->nid,
and for for !CONFIG_HAVE_MEMBLOCK_NODE_MAP builds this is a static
inline that returns 0. Note that for arm64,
CONFIG_HAVE_MEMBLOCK_NODE_MAP is selected iff CONFIG_NUMA is.

This patch makes use of memblock_get_region_node to simplify the arm64
code. At the same time, we can move the nid variable definition into the
loop, as this is the only place it is used.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NSteve Capper <steve.capper@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

we only initialize swiotlb when swiotlb_force is true or not all system
memory is DMA-able, this trivial optimization saves us 64MB when
swiotlb is not necessary.
Signed-off-by: NJisheng Zhang <jszhang@marvell.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Show the bss segment information as with text and data in Virtual
memory kernel layout.
Acked-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Each line with single pr_cont() in Virtual kernel memory layout,
or the dump of the kernel memory layout in dmesg is not aligned
when PRINTK_TIME enabled, due to the missing time stamps.
Tested-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Attempt to get the memory and CPU NUMA node via of_numa.  If that
fails, default the dummy NUMA node and map all memory and CPUs to node
0.
Tested-by: NShannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: NRobert Richter <rrichter@cavium.com>
Signed-off-by: NGanapatrao Kulkarni <gkulkarni@caviumnetworks.com>
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This moves the vmemmap region right below PAGE_OFFSET, aka the start
of the linear region, and redefines its size to be a power of two.
Due to the placement of PAGE_OFFSET in the middle of the address space,
whose size is a power of two as well, this guarantees that virt to
page conversions and vice versa can be implemented efficiently, by
masking and shifting rather than ordinary arithmetic.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The implementation of free_initmem_default() expects __init_begin
and __init_end to be covered by the linear mapping, which is no
longer the case. So open code it instead, using addresses that are
explicitly translated from kernel virtual to linear virtual.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Instead of going out of our way to relocate the initrd if it turns out
to occupy memory that is not covered by the linear mapping, just add the
initrd to the linear mapping. This puts the burden on the bootloader to
pass initrd= and mem= options that are mutually consistent.

Note that, since the placement of the linear region in the PA space is
also dependent on the placement of the kernel Image, which may reside
anywhere in memory, we may still end up with a situation where the initrd
and the kernel Image are simply too far apart to be covered by the linear
region.

Since we now leave it up to the bootloader to pass the initrd in memory
that is guaranteed to be accessible by the kernel, add a mention of this to
the arm64 boot protocol specification as well.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

After choosing memstart_addr to be the highest multiple of
ARM64_MEMSTART_ALIGN less than or equal to the first usable physical memory
address, we clip the memblocks to the maximum size of the linear region.
Since the kernel may be high up in memory, we take care not to clip the
kernel itself, which means we have to clip some memory from the bottom if
this occurs, to ensure that the distance between the first and the last
usable physical memory address can be covered by the linear region.

However, we fail to update memstart_addr if this clipping from the bottom
occurs, which means that we may still end up with virtual addresses that
wrap into the userland range. So increment memstart_addr as appropriate to
prevent this from happening.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The printk() implementation has a limit of LOG_LINE_MAX (== 1024 - 32)
buffer per call which the arm64 mem_init() breaches when printing the
virtual memory layout with CONFIG_KASAN enabled. The result is that the
last line is no longer printed. This patch splits the call into a
pr_notice() + additional pr_cont() calls.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>

Commit 8439e62a ("arm64: mm: use bit ops rather than arithmetic in
pa/va translations") changed the boundary check against PAGE_OFFSET from
an arithmetic comparison to a bit test. This means we now silently assume
that PAGE_OFFSET is a power of 2 that divides the kernel virtual address
space into two equal halves. So make that assumption explicit.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Commit c031a421 ("arm64: kaslr: randomize the linear region")
implements randomization of the linear region, by subtracting a random
multiple of PUD_SIZE from memstart_addr. This causes the virtual mapping
of system RAM to move upwards in the linear region, and at the same time
causes memstart_addr to assume a value which may be negative if the offset
of system RAM in the physical space is smaller than its offset relative to
PAGE_OFFSET in the virtual space.

Since memstart_addr is effectively an offset now, redefine its type as s64
so that expressions involving shifting or division preserve its sign.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

In the boot log, instead of listing .init first, list .text, .rodata,
.init and .data in the same order they appear in memory
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Commit dd006da2 ("arm64: mm: increase VA range of identity map") made
some changes to the memory mapping code to allow physical memory to reside
at an offset that exceeds the size of the virtual mapping.

However, since the size of the vmemmap area is proportional to the size of
the VA area, but it is populated relative to the physical space, we may
end up with the struct page array being mapped outside of the vmemmap
region. For instance, on my Seattle A0 box, I can see the following output
in the dmesg log.

   vmemmap : 0xffffffbdc0000000 - 0xffffffbfc0000000   (     8 GB maximum)
             0xffffffbfc0000000 - 0xffffffbfd0000000   (   256 MB actual)

We can fix this by deciding that the vmemmap region is not a projection of
the physical space, but of the virtual space above PAGE_OFFSET, i.e., the
linear region. This way, we are guaranteed that the vmemmap region is of
sufficient size, and we can even reduce the size by half.

Cc: <stable@vger.kernel.org>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Currently the .rodata section is actually still executable when DEBUG_RODATA
is enabled. This changes that so the .rodata is actually read only, no execute.
It also adds the .rodata section to the mem_init banner.
Signed-off-by: NJeremy Linton <jeremy.linton@arm.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
[catalin.marinas@arm.com: added vm_struct vmlinux_rodata in map_kernel()]
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Remove the unnecessary boundary check since there is a huge
gap between user and kernel address that they would never overlap.
(arm64 does not have enough levels of page tables to cover 64-bit
virtual address)

See Documentation/arm64/memory.txt
Signed-off-by: NMiles Chen <miles.chen@mediatek.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

When KASLR is enabled (CONFIG_RANDOMIZE_BASE=y), and entropy has been
provided by the bootloader, randomize the placement of RAM inside the
linear region if sufficient space is available. For instance, on a 4KB
granule/3 levels kernel, the linear region is 256 GB in size, and we can
choose any 1 GB aligned offset that is far enough from the top of the
address space to fit the distance between the start of the lowest memblock
and the top of the highest memblock.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This relaxes the kernel Image placement requirements, so that it
may be placed at any 2 MB aligned offset in physical memory.

This is accomplished by ignoring PHYS_OFFSET when installing
memblocks, and accounting for the apparent virtual offset of
the kernel Image. As a result, virtual address references
below PAGE_OFFSET are correctly mapped onto physical references
into the kernel Image regardless of where it sits in memory.

Special care needs to be taken for dealing with memory limits passed
via mem=, since the generic implementation clips memory top down, which
may clip the kernel image itself if it is loaded high up in memory. To
deal with this case, we simply add back the memory covering the kernel
image, which may result in more memory to be retained than was passed
as a mem= parameter.

Since mem= should not be considered a production feature, a panic notifier
handler is installed that dumps the memory limit at panic time if one was
set.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Before deferring the assignment of memstart_addr in a subsequent patch, to
the moment where all memory has been discovered and possibly clipped based
on the size of the linear region and the presence of a mem= command line
parameter, we need to ensure that memstart_addr is not used to perform __va
translations before it is assigned.

One such use is in the generic early DT discovery of the initrd location,
which is recorded as a virtual address in the globals initrd_start and
initrd_end. So wire up the generic support to declare the initrd addresses,
and implement it without __va() translations, and perform the translation
after memstart_addr has been assigned.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This moves the module area to right before the vmalloc area, and moves
the kernel image to the base of the vmalloc area. This is an intermediate
step towards implementing KASLR, which allows the kernel image to be
located anywhere in the vmalloc area.

Since other subsystems such as hibernate may still need to refer to the
kernel text or data segments via their linears addresses, both are mapped
in the linear region as well. The linear alias of the text region is
mapped read-only/non-executable to prevent inadvertent modification or
execution.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Currently we treat the alternatives separately from other data that's
only used during initialisation, using separate .altinstructions and
.altinstr_replacement linker sections. These are freed for general
allocation separately from .init*. This is problematic as:

* We do not remove execute permissions, as we do for .init, leaving the
  memory executable.

* We pad between them, making the kernel Image bianry up to PAGE_SIZE
  bytes larger than necessary.

This patch moves the two sections into the contiguous region used for
.init*. This saves some memory, ensures that we remove execute
permissions, and allows us to remove some code made redundant by this
reorganisation.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
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: NWill Deacon <will.deacon@arm.com>

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: NMatt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

These functions/variables are not needed after booting, so mark them
as __init or __initdata.
Signed-off-by: NJisheng Zhang <jszhang@marvell.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Trying to build with CONFIG_ZONE_DMA=n leaves visible references
to the now-undefined ZONE_DMA, resulting in a syntax error.

Hide the references behind an #ifdef instead of using IS_ENABLED.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This prints out the virtual memory assigned to KASan in the
boot crawl along with other memory assignments, if and only
if KASan is activated.

Example dmesg from the Juno Development board:

Memory: 1691156K/2080768K available (5465K kernel code, 444K rwdata,
2160K rodata, 340K init, 217K bss, 373228K reserved, 16384K cma-reserved)
Virtual kernel memory layout:
    kasan   : 0xffffff8000000000 - 0xffffff9000000000   (    64 GB)
    vmalloc : 0xffffff9000000000 - 0xffffffbdbfff0000   (   182 GB)
    vmemmap : 0xffffffbdc0000000 - 0xffffffbfc0000000   (     8 GB maximum)
              0xffffffbdc2000000 - 0xffffffbdc3fc0000   (    31 MB actual)
    fixed   : 0xffffffbffabfd000 - 0xffffffbffac00000   (    12 KB)
    PCI I/O : 0xffffffbffae00000 - 0xffffffbffbe00000   (    16 MB)
    modules : 0xffffffbffc000000 - 0xffffffc000000000   (    64 MB)
    memory  : 0xffffffc000000000 - 0xffffffc07f000000   (  2032 MB)
      .init : 0xffffffc0007f5000 - 0xffffffc00084a000   (   340 KB)
      .text : 0xffffffc000080000 - 0xffffffc0007f45b4   (  7634 KB)
      .data : 0xffffffc000850000 - 0xffffffc0008bf200   (   445 KB)
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NAndrey Ryabinin <ryabinin.a.a@gmail.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

It is not needed after booting, this patch moves the
free_initrd_mem() function to the __init section.

This patch also make keep_initrd __initdata, to reduce kernel
size.
Signed-off-by: NWang Long <long.wanglong@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The memmap freeing code in free_unused_memmap() computes the end of
each memblock by adding the memblock size onto the base.  However,
if SPARSEMEM is enabled then the value (start) used for the base
may already have been rounded downwards to work out which memmap
entries to free after the previous memblock.

This may cause memmap entries that are in use to get freed.

In general, you're not likely to hit this problem unless there
are at least 2 memblocks and one of them is not aligned to a
sparsemem section boundary.  Note that carve-outs can increase
the number of memblocks by splitting the regions listed in the
device tree.

This problem doesn't occur with SPARSEMEM_VMEMMAP, because the
vmemmap code deals with freeing the unused regions of the memmap
instead of requiring the arch code to do it.

This patch gets the memblock base out of the memblock directly when
computing the block end address to ensure the correct value is used.
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

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: NMark Rutland <mark.rutland@arm.com>
Tested-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This splits off the reservation of the memory occupied by the FDT
binary itself from the processing of the memory reservations it
contains. This is necessary because the physical address of the FDT,
which is needed to perform the reservation, may not be known to the
FDT driver core, i.e., it may be mapped outside the linear direct
mapping, in which case __pa() returns a bogus value.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NRob Herring <robh@kernel.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Add support for memtest command line option.
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Tested-by: NMark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With commit 3690951f (arm64: Use swiotlb late initialisation), the
swiotlb buffer size is limited to MAX_ORDER_NR_PAGES. However, there are
platforms with 32-bit only devices that require bounce buffering via
swiotlb. This patch changes the swiotlb initialisation to an early 64MB
memblock allocation. In order to get the swiotlb buffer correctly
allocated (via memblock_virt_alloc_low_nopanic), this patch also defines
ARCH_LOW_ADDRESS_LIMIT to the maximum physical address capable of 32-bit
DMA.
Reported-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

PCI IO space was intended to be 16MiB, at 32MiB below MODULES_VADDR, but
commit d1e6dc91 ("arm64: Add architectural support for PCI")
extended this to cover the full 32MiB. The final 8KiB of this 32MiB is
also allocated for the fixmap, allowing for potential clashes between
the two.

This change was masked by assumptions in mem_init and the page table
dumping code, which assumed the I/O space to be 16MiB long through
seaparte hard-coded definitions.

This patch changes the definition of the PCI I/O space allocation to
live in asm/memory.h, along with the other VA space allocations. As the
fixmap allocation depends on the number of fixmap entries, this is moved
below the PCI I/O space allocation. Both the fixmap and PCI I/O space
are guarded with 2MB of padding. Sites assuming the I/O space was 16MiB
are moved over use new PCI_IO_{START,END} definitions, which will keep
in sync with the size of the IO space (now restored to 16MiB).

As a useful side effect, the use of the new PCI_IO_{START,END}
definitions prevents a build issue in the dumping code due to a (now
redundant) missing include of io.h for PCI_IOBASE.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
[catalin.marinas@arm.com: reorder FIXADDR and PCI_IO address_markers_idx enum]
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

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: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: NKees Cook <keescook@chromium.org>
Tested-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NLaura Abbott <lauraa@codeaurora.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

When booting with EFI, we acquire the EFI memory map after parsing the
early params. This unfortuantely renders the option useless as we call
memblock_enforce_memory_limit (which uses memblock_remove_range behind
the scenes) before we've added any memblocks. We end up removing
nothing, then adding all of memory later when efi_init calls
reserve_regions.

Instead, we can log the limit and apply this later when we do the rest
of the memblock work in memblock_init, which should work regardless of
the presence of EFI. At the same time we may as well move the early
parameter into arm64's mm/init.c, close to arm64_memblock_init.

Any memory which must be mapped (e.g. for use by EFI runtime services)
must be mapped explicitly reather than relying on the linear mapping,
which may be truncated as a result of a mem= option passed on the kernel
command line.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This patch partially reverts commit 421520ba
(only the arm64 part). There is no guarantee that the boot-loader places other
images like dtb in a different page than initrd start/end, especially when the
kernel is built with 64KB pages. When this happens, such pages must not be
freed. The free_reserved_area() already takes care of rounding up "start" and
rounding down "end" to avoid freeing partially used pages.

Cc: <stable@vger.kernel.org> # 3.17+
Reported-by: NPeter Maydell <Peter.Maydell@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

With a blatant copy of some x86 bits we introduce the alternative
runtime patching "framework" to arm64.
This is quite basic for now and we only provide the functions we need
at this time.
This is connected to the newly introduced feature bits.
Signed-off-by: NAndre Przywara <andre.przywara@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This patch extends the start and end address of initrd to be page aligned,
so that we can free all memory including the un-page aligned head or tail
page of initrd, if the start or end address of initrd are not page
aligned, the page can't be freed by free_initrd_mem() function.
Signed-off-by: NYalin Wang <yalin.wang@sonymobile.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>