For historical reasons, the kernel Image must be loaded into physical
memory at a 512 KB offset above a 2 MB aligned base address. The region
between the base address and the start of the kernel Image has no
significance to the kernel itself, but it is currently mapped explicitly
into the early kernel VMA range for all translation granules.

In some cases (i.e., 4 KB granule), this is unavoidable, due to the 2 MB
granularity of the early kernel mappings. However, in other cases, e.g.,
when running with larger page sizes, or in the future, with more granular
KASLR, there is no reason to map it explicitly like we do currently.

So update the logic so that the region is mapped only if that happens as
a side effect of rounding the start address of the kernel to swapper block
size, and leave it unmapped otherwise.

Since the symbol kernel_img_size now simply resolves to the memory
footprint of the kernel Image, we can drop its definition from image.h
and opencode its calculation.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When building a relocatable kernel, we currently rely on the fact that
early 64-bit literal loads need to be deferred to after the relocation
has been performed only if they involve symbol references, and not if
they involve assemble time constants. While this is not an unreasonable
assumption to make, it is better to switch to movk/movz sequences, since
these are guaranteed to be resolved at link time, simply because there are
no dynamic relocation types to describe them.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Implement a macro mov_q that can be used to move an immediate constant
into a 64-bit register, using between 2 and 4 movz/movk instructions
(depending on the operand)
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Refactor the relocation processing so that the code executes from the
ID map while accessing the relocation tables via the virtual mapping.
This way, we can use literals containing virtual addresses as before,
instead of having to use convoluted absolute expressions.

For symmetry with the secondary code path, the relocation code and the
subsequent jump to the virtual entry point are implemented in a function
called __primary_switch(), and __mmap_switched() is renamed to
__primary_switched(). Also, the call sequence in stext() is aligned with
the one in secondary_startup(), by replacing the awkward 'adr_l lr' and
'b cpu_setup' sequence with a simple branch and link.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

We can simply use a relocated 64-bit literal to store the address of
__secondary_switched(), and the relocation code will ensure that it
holds the correct value at secondary entry time, as long as we make sure
that the literal is not dereferenced until after we have enabled the MMU.

So jump via a small __secondary_switch() function covered by the ID map
that performs the literal load and branch-to-register.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This unexports some symbols from head.S that are only used locally.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

maxcpu=n sets the number of CPUs activated at boot time to a max of n,
but allowing the remaining CPUs to be brought up later if the user
decides to do so. However, on arm64 due to various reasons, we disallowed
hotplugging CPUs beyond n, by marking them not present. Now that
we have checks in place to make sure the hotplugged CPUs have compatible
features with system and requires no new errata, relax the restriction.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

CPU Errata work arounds are detected and applied to the
kernel code at boot time and the data is then freed up.
If a new hotplugged CPU requires a work around which
was not applied at boot time, there is nothing we can
do but simply fail the booting.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When introducing the whole CPU feature detection framework,
we lost the capability to detect a mismatched GIC configuration
(using the GICv2 MMIO interface, but having the system register
interface enabled).

In order to solve this, use the new this_cpu_has_cap() helper.
Also move the check to the CPU interface path in order to catch
systems where the first CPU has been correctly configured,
but the secondaries are not.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Now that the capabilities are only available once all the CPUs
have booted, we're unable to check for a particular feature
in any subsystem that gets initialized before then.

In order to support this, introduce a local_cpu_has_cap() function
that tests for the presence of a given capability independently
of the whole framework.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
[ Added preemptible() check ]
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
[will: remove duplicate initialisation of caps in this_cpu_has_cap]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Add scope parameter to the arm64_cpu_capabilities::matches(), so that
this can be reused for checking the capability on a given CPU vs the
system wide. The system uses the default scope associated with the
capability for initialising the CPU_HWCAPs and ELF_HWCAPs.

Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Improve the readability of dt_scan_depth1_nodes by removing the nested
conditionals.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NStefano Stabellini <sstabellini@kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When it's a Xen domain0 booting with ACPI, it will supply a /chosen and
a /hypervisor node in DT. So check if it needs to enable ACPI.
Signed-off-by: NShannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: NHanjun Guo <hanjun.guo@linaro.org>
Tested-by: NJulien Grall <julien.grall@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Annotate the KASAN shadow region with boundary markers, so that its
mappings stand out in the page table dumper output.
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

There is no need to initialize the vmemmap region boundaries dynamically,
since they are compile time constants. So just add these constants to the
global struct initializer, and drop the dynamic assignment and related code.
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The open coded conversion from struct page address to virtual address in
lowmem_page_address() involves an intermediate conversion step to pfn
number/physical address. Since the placement of the struct page array
relative to the linear mapping may be completely independent from the
placement of physical RAM (as is that case for arm64 after commit
dfd55ad8 'arm64: vmemmap: use virtual projection of linear region'),
the conversion to physical address and back again should factor out of
the equation, but unfortunately, the shifting and pointer arithmetic
involved prevent this from happening, and the resulting calculation
essentially subtracts the address of the start of physical memory and
adds it back again, in a way that prevents the compiler from optimizing
it away.

Since the start of physical memory is not a build time constant on arm64,
the resulting conversion involves an unnecessary memory access, which
we would like to get rid of. So replace the open coded conversion with
a call to page_to_virt(), and use the open coded conversion as its
default definition, to be overriden by the architecture, if desired.
The existing arch specific definitions of page_to_virt are all equivalent
to this default definition, so by itself this patch is a no-op.
Acked-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

To align with generic code and other architectures that expect the macro
page_to_virt to produce an expression whose type is 'void*', drop the
arch specific definition, which is never referenced anyway.
Acked-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

To align with other architectures, the expression produced by expanding
the macro page_to_virt() should be of type void*, since it returns a
virtual address. Fix that, and also fix up an instance where page_to_virt
was expected to return 'unsigned long', and drop another instance that was
entirely unused (page_to_bus)
Acked-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

With the IOMMU core now taking care of default domains for groups
regardless of bus type, we can gleefully rip out this stop-gap, as
slight recompense for having to expand the other one.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

PCI devices now suffer the same hiccup as platform devices, in that they
get their DMA ops configured before they have been added to their bus,
and thus before we know whether they have successfully registered with
an IOMMU or not. Until the necessary driver core changes to reorder
calls during device creation have been worked out, extend our delayed
notifier trick onto the PCI bus so as to avoid broken DMA ops once
IOMMUs get plugged into the PCI code.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Make sure we have AArch32 state available for running COMPAT
binaries and also for switching the personality to PER_LINUX32.
Signed-off-by: NYury Norov <ynorov@caviumnetworks.com>
[ Added cap bit, checks for HWCAP, personality ]
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: NYury Norov <ynorov@caviumnetworks.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Add cpu_hwcap bit for keeping track of the support for 32bit EL0.
Tested-by: NYury Norov <ynorov@caviumnetworks.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

On ARMv8 support for AArch32 state is optional. Hence it is
not safe to check the AArch32 ID registers for sanity, which
could lead to false warnings. This patch makes sure that the
AArch32 state is implemented before we keep track of the 32bit
ID registers.

As per ARM ARM (D.1.21.2 - Support for Exception Levels and
Execution States, DDI0487A.h), checking the support for AArch32
at EL0 is good enough to check the support for AArch32 (i.e,
AArch32 at EL1 => AArch32 at EL0, but not vice versa).
Tested-by: NYury Norov <ynorov@caviumnetworks.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Adds a helper to extract the support for AArch32 at EL0
Tested-by: NYury Norov <ynorov@caviumnetworks.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

In order to handle systems which do not support 32bit at EL0,
split the COMPAT HWCAP entries into a separate table which can
be processed, only if the support is available.
Tested-by: NYury Norov <ynorov@caviumnetworks.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

We use hwcaps for referring to ELF hwcaps capability information.
However this can be confusing with 'cpu_hwcaps' which stands for the
CPU capability bit field. This patch cleans up the names to make it
a bit more readable.
Tested-by: NYury Norov <ynorov@caviumnetworks.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

We haven't used the push/pop macros for a while now, as it's typically
better to use immediate offsets for batches of accesses to the stack, as
we now do in the entry assembly for the kernel and hyp code.

Remove the unused macros.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

HAVE_ARCH_TRANSPARENT_HUGEPAGE has been defined in arch/Kconfig already,
the ARM64 version is identical with it and the default value is Y. So remove
the redundant definition and just select it under CONFIG_ARM64.
Signed-off-by: NYang Shi <yang.shi@linaro.org>
[will: sort into alphabetical order whilst I'm resolving conflicts]
Signed-off-by: NWill Deacon <will.deacon@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>

memblock_remove() takes a phys_addr_t, which may be narrower than 64 bits,
causing a harmless warning:

drivers/firmware/efi/arm-init.c: In function 'reserve_regions':
include/linux/kernel.h:29:20: error: large integer implicitly truncated to unsigned type [-Werror=overflow]
 #define ULLONG_MAX (~0ULL)
                    ^
drivers/firmware/efi/arm-init.c:152:21: note: in expansion of macro 'ULLONG_MAX'
  memblock_remove(0, ULLONG_MAX);

This adds an explicit typecast to avoid the warning

Fixes: 500899c2 ("efi: ARM/arm64: ignore DT memory nodes instead of removing them")
Acked-by Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NMatt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When CPUs are stopped during an abnormal operation like panic
for each CPU a line is printed and the stack trace is dumped.

This information is only interesting for the aborting CPU
and on systems with many CPUs it only makes it harder to
debug if after the aborting CPU the log is flooded with data
about all other CPUs too.

Therefore remove the stack dump and printk of other CPUs
and only print a single line that the other CPUs are going to be
stopped and, in case any CPUs remain online list them.
Signed-off-by: NJan Glauber <jglauber@cavium.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

We already re-enable interrupts where necessary in the entry code, so
there is no need to do it again in do_page fault. This patch removes
the redundant code.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NHuang Shijie <shijie.huang@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When hardware updates of the access and dirty states are enabled, the
default ptep_set_access_flags() implementation based on calling
set_pte_at() directly is potentially racy. This triggers the "racy dirty
state clearing" warning in set_pte_at() because an existing writable PTE
is overridden with a clean entry.

There are two main scenarios for this situation:

1. The CPU getting an access fault does not support hardware updates of
   the access/dirty flags. However, a different agent in the system
   (e.g. SMMU) can do this, therefore overriding a writable entry with a
   clean one could potentially lose the automatically updated dirty
   status

2. A more complex situation is possible when all CPUs support hardware
   AF/DBM:

   a) Initial state: shareable + writable vma and pte_none(pte)
   b) Read fault taken by two threads of the same process on different
      CPUs
   c) CPU0 takes the mmap_sem and proceeds to handling the fault. It
      eventually reaches do_set_pte() which sets a writable + clean pte.
      CPU0 releases the mmap_sem
   d) CPU1 acquires the mmap_sem and proceeds to handle_pte_fault(). The
      pte entry it reads is present, writable and clean and it continues
      to pte_mkyoung()
   e) CPU1 calls ptep_set_access_flags()

   If between (d) and (e) the hardware (another CPU) updates the dirty
   state (clears PTE_RDONLY), CPU1 will override the PTR_RDONLY bit
   marking the entry clean again.

This patch implements an arm64-specific ptep_set_access_flags() function
to perform an atomic update of the PTE flags.

Fixes: 2f4b829c ("arm64: Add support for hardware updates of the access and dirty pte bits")
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Reported-by: NMing Lei <tom.leiming@gmail.com>
Tested-by: NJulien Grall <julien.grall@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org> # 4.3+
[will: reworded comment]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Enable NUMA balancing for arm64 platforms.
Add pte, pmd protnone helpers for use by automatic NUMA balancing.
Reviewed-by: NSteve Capper <steve.capper@arm.com>
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>

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>

In order to extract NUMA information from the device tree, we need to
have the tree in its unflattened form.

Move the call to bootmem_init() in the tail of paging_init() into
setup_arch, and adjust header files so that its declaration is
visible.

Move the unflatten_device_tree() call between the calls to
paging_init() and bootmem_init().  Follow on patches add NUMA handling
to bootmem_init().
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Add device tree parsing for NUMA topology using device
"numa-node-id" property in distance-map and cpu nodes.

This is a complete rewrite of a previous patch by:
   Ganapatrao Kulkarni<gkulkarni@caviumnetworks.com>
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Add DT bindings for numa mapping of memory, CPUs and IOs.
Reviewed-by: NRobert Richter <rrichter@cavium.com>
Signed-off-by: NGanapatrao Kulkarni <gkulkarni@caviumnetworks.com>
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

There are two problems with the UEFI stub DT memory node removal
routine:
- it deletes nodes as it traverses the tree, which happens to work
  but is not supported, as deletion invalidates the node iterator;
- deleting memory nodes entirely may discard annotations in the form
  of additional properties on the nodes.

Since the discovery of DT memory nodes occurs strictly before the
UEFI init sequence, we can simply clear the memblock memory table
before parsing the UEFI memory map. This way, it is no longer
necessary to remove the nodes, so we can remove that logic from the
stub as well.
Reviewed-by: NMatt Fleming <matt@codeblueprint.co.uk>
Acked-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>