There is some code that exposes physical addresses of certain parts of
the EFI firmware implementation via sysfs nodes. These nodes are only
used on x86, and are of dubious value to begin with, so let's move
their handling into the x86 arch code.

Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>

config_parse_tables() is a jumble of pointer arithmetic, due to the
fact that on x86, we may be dealing with firmware whose native word
size differs from the kernel's.

This is not a concern on other architectures, and doesn't quite
justify the state of the code, so let's clean it up by adding a
non-x86 code path, constifying statically allocated tables and
replacing preprocessor conditionals with IS_ENABLED() checks.

Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>

We have three different versions of the code that checks the EFI system
table revision and copies the firmware vendor string, and they are
mostly equivalent, with the exception of the use of early_memremap_ro
vs. __va() and the lowest major revision to warn about. Let's move this
into common code and factor out the commonalities.

Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>

The new of_devlink support breaks PCIe probing on ARM platforms booting
via UEFI if the firmware exposes a EFI framebuffer that is backed by a
PCI device. The reason is that the probing order gets reversed,
resulting in a resource conflict on the framebuffer memory window when
the PCIe probes last, causing it to give up entirely.

Given that we rely on PCI quirks to deal with EFI framebuffers that get
moved around in memory, we cannot simply drop the memory reservation, so
instead, let's use the device link infrastructure to register this
dependency, and force the probing to occur in the expected order.
Co-developed-by: NSaravana Kannan <saravanak@google.com>
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>
Signed-off-by: NSaravana Kannan <saravanak@google.com>
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200113172245.27925-9-ardb@kernel.org

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

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

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

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

Replace all GPL license blurbs with an equivalent SPDX header (most
files are GPLv2, some are GPLv2+). While at it, drop some outdated
header changelogs as well.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Alexander Graf <agraf@suse.de>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Jeffrey Hugo <jhugo@codeaurora.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190202094119.13230-7-ard.biesheuvel@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Commit:

  3ea86495 ("efi/arm: preserve early mapping of UEFI memory map longer for BGRT")

deferred the unmap of the early mapping of the UEFI memory map to
accommodate the ACPI BGRT code, which looks up the memory type that
backs the BGRT table to validate it against the requirements of the UEFI spec.

Unfortunately, this causes problems on ARM, which does not permit
early mappings to persist after paging_init() is called, resulting
in a WARN() splat. Since we don't support the BGRT table on ARM anway,
let's revert ARM to the old behaviour, which is to take down the
early mapping at the end of efi_init().
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 3ea86495 ("efi/arm: preserve early mapping of UEFI memory ...")
Link: http://lkml.kernel.org/r/20181114175544.12860-3-ard.biesheuvel@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

The BGRT code validates the contents of the table against the UEFI
memory map, and so it expects it to be mapped when the code runs.

On ARM, this is currently not the case, since we tear down the early
mapping after efi_init() completes, and only create the permanent
mapping in arm_enable_runtime_services(), which executes as an early
initcall, but still leaves a window where the UEFI memory map is not
mapped.

So move the call to efi_memmap_unmap() from efi_init() to
arm_enable_runtime_services().
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
[will: fold in EFI_MEMMAP attribute check from Ard]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

With PHYS_ADDR_MAX there is now a type safe variant for all bits set.
Make use of it.

Patch created using a semantic patch as follows:

// <smpl>
@@
typedef phys_addr_t;
@@
-(phys_addr_t)ULLONG_MAX
+PHYS_ADDR_MAX
// </smpl>

Link: http://lkml.kernel.org/r/20180419214204.19322-1-stefan@agner.chSigned-off-by: NStefan Agner <stefan@agner.ch>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ARM EFI init code never assigns the config_table member of the
efi struct, which means the sysfs device node is missing, and other
in-kernel users will not work correctly. So add the missing assignment.

Note that, for now, the runtime and fw_vendor members are still
omitted. This is deliberate: exposing physical addresses via sysfs nodes
encourages behavior that we would like to avoid on ARM (given how it is
more finicky about using correct memory attributes when mapping memory
in userland that may be mapped by the kernel already as well).
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170818194947.19347-6-ard.biesheuvel@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

On ARM, regions of memory that are described by UEFI as having special
significance to the firmware itself are omitted from the linear mapping.
This is necessary since we cannot guarantee that alternate mappings of
the same physical region will use attributes that are compatible with
the ones we use for the linear mapping, and aliases with mismatched
attributes are prohibited by the architecture.

The above does not apply to ACPI reclaim regions: such regions have no
special significance to the firmware, and it is up to the OS to decide
whether or not to preserve them after it has consumed their contents,
and for how long, after which time the OS can use the memory in any way
it likes. In the Linux case, such regions are preserved indefinitely,
and are simply treated the same way as other 'reserved' memory types.

Punching holes into the linear mapping causes page table fragmentation,
which increases TLB pressure, and so we should avoid doing so if we can.
So add a special case for regions of type EFI_ACPI_RECLAIM_MEMORY, and
memblock_reserve() them instead of marking them MEMBLOCK_NOMAP.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170818194947.19347-2-ard.biesheuvel@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Since EFI_PROPERTIES_TABLE and EFI_MEMORY_ATTRIBUTES_TABLE deal with
updating memory region attributes, it makes sense to call
EFI_MEMORY_ATTRIBUTES_TABLE initialization function from the same place
as EFI_PROPERTIES_TABLE. This also moves the EFI_MEMORY_ATTRIBUTES_TABLE
initialization code to a more generic efi initialization path rather
than ARM specific efi initialization. This is important because
EFI_MEMORY_ATTRIBUTES_TABLE will be supported by x86 as well.
Signed-off-by: NSai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NLee, Chun-Yi <jlee@suse.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1485868902-20401-4-git-send-email-ard.biesheuvel@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

There's an early memmap() leak in the efi_init() error path, fix it.
Signed-off-by: NYisheng Xie <xieyisheng1@huawei.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20161018143318.15673-4-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>

Currently, memory regions are only recorded in the memblock memory table
if they have the EFI_MEMORY_WB memory type attribute set. In case the
region is of a reserved type, it is also marked as MEMBLOCK_NOMAP, which
will leave it out of the linear mapping.

However, memory regions may legally have the EFI_MEMORY_WT or EFI_MEMORY_WC
attributes set, and the EFI_MEMORY_WB cleared, in which case the region in
question is obviously backed by normal memory, but is not recorded in the
memblock memory table at all. Since it would be useful to be able to
identify any UEFI reported memory region using memblock_is_memory(), it
makes sense to add all memory to the memblock memory table, and simply mark
it as MEMBLOCK_NOMAP if it lacks the EFI_MEMORY_WB attribute.

While implementing this, let's refactor the code slightly to make it easier
to understand: replace is_normal_ram() with is_memory(), and make it return
true for each region that has any of the WB|WT|WC bits set. (This follows
the AArch64 bindings in the UEFI spec, which state that those are the
attributes that map to normal memory)

Also, replace is_reserve_region() with is_usable_memory(), and only invoke
it if the region in question was identified as memory by is_memory() in the
first place. The net result is the same (only reserved regions that are
backed by memory end up in the memblock memory table with the MEMBLOCK_NOMAP
flag set) but carried out in a more straightforward way.

Finally, we remove the trailing asterisk in the EFI debug output. Keeping it
clutters the code, and it serves no real purpose now that we no longer
temporarily reserve BootServices code and data regions like we did in the
early days of EFI support on arm64 Linux (which it inherited from the x86
implementation)
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NLeif Lindholm <leif.lindholm@linaro.org>
Tested-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>

ESRT support is built by default for all architectures that define
CONFIG_EFI. However, this support was not wired up yet for ARM/arm64,
since efi_esrt_init() was never called. So add the missing call.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Jones <pjones@redhat.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>

Every EFI architecture apart from ia64 needs to setup the EFI memory
map at efi.memmap, and the code for doing that is essentially the same
across all implementations. Therefore, it makes sense to factor this
out into the common code under drivers/firmware/efi/.

The only slight variation is the data structure out of which we pull
the initial memory map information, such as physical address, memory
descriptor size and version, etc. We can address this by passing a
generic data structure (struct efi_memory_map_data) as the argument to
efi_memmap_init_early() which contains the minimum info required for
initialising the memory map.

In the process, this patch also fixes a few undesirable implementation
differences:

 - ARM and arm64 were failing to clear the EFI_MEMMAP bit when
   unmapping the early EFI memory map. EFI_MEMMAP indicates whether
   the EFI memory map is mapped (not the regions contained within) and
   can be traversed.  It's more correct to set the bit as soon as we
   memremap() the passed in EFI memmap.

 - Rename efi_unmmap_memmap() to efi_memmap_unmap() to adhere to the
   regular naming scheme.

This patch also uses a read-write mapping for the memory map instead
of the read-only mapping currently used on ARM and arm64. x86 needs
the ability to update the memory map in-place when assigning virtual
addresses to regions (efi_map_region()) and tagging regions when
reserving boot services (efi_reserve_boot_services()).

There's no way for the generic fake_mem code to know which mapping to
use without introducing some arch-specific constant/hook, so just use
read-write since read-only is of dubious value for the EFI memory map.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>

When both EFI and memblock debugging is enabled on the kernel command line:

  'efi=debug memblock=debug'

.. the debug messages for early_con look the following way:

 [    0.000000] efi:   0x0000e1050000-0x0000e105ffff [Memory Mapped I/O  |RUN|  |  |  |  |  |  |   |  |  |  |UC]
 [    0.000000] efi:   0x0000e1300000-0x0000e1300fff [Memory Mapped I/O  |RUN|  |  |  |  |  |  |   |  |  |  |UC]
 [    0.000000] efi:   0x0000e8200000-0x0000e827ffff [Memory Mapped I/O  |RUN|  |  |  |  |  |  |   |  |  |  |UC]
 [    0.000000] efi:   0x008000000000-0x008001e7ffff [Runtime Data       |RUN|  |  |  |  |  |  |   |WB|WT|WC|UC]
 [    0.000000] memblock_add: [0x00008000000000-0x00008001e7ffff] flags 0x0 early_init_dt_add_memory_arch+0x54/0x5c
 [    0.000000] *
 ...

Note the misplaced '*' line, which happened because the memblock debug message
was printed while the EFI debug message was still being constructed..

This patch fixes the output to be the expected:

 [    0.000000] efi:   0x0000e1050000-0x0000e105ffff [Memory Mapped I/O  |RUN|  |  |  |  |  |  |   |  |  |  |UC]
 [    0.000000] efi:   0x0000e1300000-0x0000e1300fff [Memory Mapped I/O  |RUN|  |  |  |  |  |  |   |  |  |  |UC]
 [    0.000000] efi:   0x0000e8200000-0x0000e827ffff [Memory Mapped I/O  |RUN|  |  |  |  |  |  |   |  |  |  |UC]
 [    0.000000] efi:   0x008000000000-0x008001e7ffff [Runtime Data       |RUN|  |  |  |  |  |  |   |WB|WT|WC|UC]*
 [    0.000000] memblock_add: [0x00008000000000-0x00008001e7ffff] flags 0x0 early_init_dt_add_memory_arch+0x54/0x5c
 ...

Note how the '*' is now in the proper EFI debug message line.
Signed-off-by: NDennis Chen <dennis.chen@arm.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Steve McIntyre <steve@einval.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1464690224-4503-3-git-send-email-matt@codeblueprint.co.uk
[ Made the changelog more readable. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Now that ARM has a fully functional memremap() implementation, there is
no longer a need to remove the UEFI memory map from the linear mapping
in order to be able to create a permanent mapping for it using generic
code.

So remove the 'IS_ENABLED(CONFIG_ARM)' conditional we added in:

7cc8cbcf ("efi/arm64: Don't apply MEMBLOCK_NOMAP to UEFI memory map mapping")

... and revert to using memblock_reserve() for both ARM and arm64.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-31-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>

This adds code to the ARM and arm64 EFI init routines to expose a platform
device of type 'efi-framebuffer' if 'struct screen_info' has been populated
appropriately from the GOP protocol by the stub. Since the framebuffer may
potentially be located in system RAM, make sure that the region is reserved
and marked MEMBLOCK_NOMAP.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-24-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>

In order to hand over the framebuffer described by the GOP protocol and
discovered by the UEFI stub, make struct screen_info accessible by the
stub. This involves allocating a loader data buffer and passing it to the
kernel proper via a UEFI Configuration Table, since the UEFI stub executes
in the context of the decompressor, and cannot access the kernel's copy of
struct screen_info directly.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-22-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>

Call into the generic memory attributes table support code at the
appropriate times during the init sequence so that the UEFI Runtime
Services region are mapped according to the strict permissions it
specifies.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-15-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>

Our efi_memory_desc_t type is based on EFI_MEMORY_DESCRIPTOR version 1 in
the UEFI spec. No version updates are expected, but since we are about to
introduce support for new firmware tables that use the same descriptor
type, it makes sense to at least warn if we encounter other versions.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-9-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>

Abolish the poorly named EFI memory map, 'memmap'. It is shadowed by a
bunch of local definitions in various files and having two ways to
access the EFI memory map ('efi.memmap' vs. 'memmap') is rather
confusing.

Furthermore, IA64 doesn't even provide this global object, which has
caused issues when trying to write generic EFI memmap code.

Replace all occurrences with efi.memmap, and convert the remaining
iterator code to use for_each_efi_mem_desc().
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Luck, Tony <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-8-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>

Most of the users of for_each_efi_memory_desc() are equally happy
iterating over the EFI memory map in efi.memmap instead of 'memmap',
since the former is usually a pointer to the latter.

For those users that want to specify an EFI memory map other than
efi.memmap, that can be done using for_each_efi_memory_desc_in_map().
One such example is in the libstub code where the firmware is queried
directly for the memory map, it gets iterated over, and then freed.

This change goes part of the way toward deleting the global 'memmap'
variable, which is not universally available on all architectures
(notably IA64) and is rather poorly named.
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-7-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>

Commit:

  2eec5ded ("efi/arm-init: Use read-only early mappings")

updated the early ARM UEFI init code to create the temporary, early
mapping of the UEFI System table using read-only attributes, as a
hardening measure against inadvertent modification.

However, this still leaves the permanent, writable mapping of the UEFI
System table, which is only ever referenced during invocations of UEFI
Runtime Services, at which time the UEFI virtual mapping is available,
which also covers the system table. (This is guaranteed by the fact that
SetVirtualAddressMap(), which is a runtime service itself, converts
various entries in the table to their virtual equivalents, which implies
that the table must be covered by a RuntimeServicesData region that has
the EFI_MEMORY_RUNTIME attribute.)

So instead of creating this permanent mapping, record the virtual address
of the system table inside the UEFI virtual mapping, and dereference that
when accessing the table. This protects the contents of the system table
from inadvertent (or deliberate) modification when no UEFI Runtime
Services calls are in progress.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-3-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>

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>

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>

Commit 4dffbfc4 ("arm64/efi: mark UEFI reserved regions as
MEMBLOCK_NOMAP") updated the mapping logic of both the RuntimeServices
regions as well as the kernel's copy of the UEFI memory map to set the
MEMBLOCK_NOMAP flag, which causes these regions to be omitted from the
kernel direct mapping, and from being covered by a struct page.
For the RuntimeServices regions, this is an obvious win, since the contents
of these regions have significance to the firmware executable code itself,
and are mapped in the EFI page tables using attributes that are described in
the UEFI memory map, and which may differ from the attributes we use for
mapping system RAM. It also prevents the contents from being modified
inadvertently, since the EFI page tables are only live during runtime
service invocations.

None of these concerns apply to the allocation that covers the UEFI memory
map, since it is entirely owned by the kernel. Setting the MEMBLOCK_NOMAP on
the region did allow us to use ioremap_cache() to map it both on arm64 and
on ARM, since the latter does not allow ioremap_cache() to be used on
regions that are covered by a struct page.

The ioremap_cache() on ARM restriction will be lifted in the v4.7 timeframe,
but in the mean time, it has been reported that commit 4dffbfc4 causes
a regression on 64k granule kernels. This is due to the fact that, given
the 64 KB page size, the region that we end up removing from the kernel
direct mapping is rounded up to 64 KB, and this 64 KB page frame may be
shared with the initrd when booting via GRUB (which does not align its
EFI_LOADER_DATA allocations to 64 KB like the stub does). This will crash
the kernel as soon as it tries to access the initrd.

Since the issue is specific to arm64, revert back to memblock_reserve()'ing
the UEFI memory map when running on arm64. This is a temporary fix for v4.5
and v4.6, and will be superseded in the v4.7 timeframe when we will be able
to move back to memblock_reserve() unconditionally.

Fixes: 4dffbfc4 ("arm64/efi: mark UEFI reserved regions as MEMBLOCK_NOMAP")
Reported-by: NMark Salter <msalter@redhat.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Mark Langsdorf <mlangsdo@redhat.com>
Cc: <stable@vger.kernel.org> # v4.5
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>

The early mappings of the EFI system table contents and the UEFI memory
map are read-only from the OS point of view. So map them read-only to
protect them from inadvertent modification.
Tested-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1455712566-16727-8-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>

This refactors the EFI init and runtime code that will be shared
between arm64 and ARM so that it can be built for both archs.
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>

This splits off the early EFI init and runtime code that
- discovers the EFI params and the memory map from the FDT, and installs
  the memblocks and config tables.
- prepares and installs the EFI page tables so that UEFI Runtime Services
  can be invoked at the virtual address installed by the stub.

This will allow it to be reused for 32-bit ARM.
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>

Change the EFI memory reservation logic to use memblock_mark_nomap()
rather than memblock_reserve() to mark UEFI reserved regions as
occupied. In addition to reserving them against allocations done by
memblock, this will also prevent them from being covered by the linear
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>

Even though initcall return values are typically ignored, the
prototype is to return 0 on success or a negative errno value on
error. So fix the arm_enable_runtime_services() implementation to
return 0 on conditions that are not in fact errors, and return a
meaningful error code otherwise.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NMatt Fleming <matt@codeblueprint.co.uk>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Add NULL return value checks to two invocations of early_memremap()
in the UEFI init code. For the UEFI configuration tables, we just
warn since we have a better chance of being able to report the issue
in a way that can actually be noticed by a human operator if we don't
abort right away. For the UEFI memory map, however, all we can do is
panic() since we cannot proceed without a description of memory.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NMatt Fleming <matt@codeblueprint.co.uk>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The kernel may use a page granularity of 4K, 16K, or 64K depending on
configuration.

When mapping EFI runtime regions, we use memrange_efi_to_native to round
the physical base address of a region down to a kernel page boundary,
and round the size up to a kernel page boundary, adding the residue left
over from rounding down the physical base address. We do not round down
the virtual base address.

In __create_mapping we account for the offset of the virtual base from a
granule boundary, adding the residue to the size before rounding the
base down to said granule boundary.

Thus we account for the residue twice, and when the residue is non-zero
will cause __create_mapping to map an additional page at the end of the
region. Depending on the memory map, this page may be in a region we are
not intended/permitted to map, or may clash with a different region that
we wish to map. In typical cases, mapping the next item in the memory
map will overwrite the erroneously created entry, as we sort the memory
map in the stub.

As __create_mapping can cope with base addresses which are not page
aligned, we can instead rely on it to map the region appropriately, and
simplify efi_virtmap_init by removing the unnecessary code.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-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>

As pointed out by Russell King in response to the proposed ARM version
of this code, the sequence to switch between the UEFI runtime mapping
and current's actual userland mapping (and vice versa) is potentially
unsafe, since it leaves a time window between the switch to the new
page tables and the TLB flush where speculative accesses may hit on
stale global TLB entries.

So instead, use non-global mappings, and perform the switch via the
ordinary ASID-aware context switch routines.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

We have been getting away with using a void* for the physical
address of the UEFI memory map, since, even on 32-bit platforms
with 64-bit physical addresses, no truncation takes place if the
memory map has been allocated by the firmware (which only uses
1:1 virtually addressable memory), which is usually the case.

However, commit:

  0f96a99d ("efi: Add "efi_fake_mem" boot option")

adds code that clones and modifies the UEFI memory map, and the
clone may live above 4 GB on 32-bit platforms.

This means our use of void* for struct efi_memory_map::phys_map has
graduated from 'incorrect but working' to 'incorrect and
broken', and we need to fix it.

So redefine struct efi_memory_map::phys_map as phys_addr_t, and
get rid of a bunch of casts that are now unneeded.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: izumi.taku@jp.fujitsu.com
Cc: kamezawa.hiroyu@jp.fujitsu.com
Cc: linux-efi@vger.kernel.org
Cc: matt.fleming@intel.com
Link: http://lkml.kernel.org/r/1445593697-1342-1-git-send-email-ard.biesheuvel@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

As we now have a common debug infrastructure between core and arm64 efi,
drop the bit of the interface passing verbose output flags around.
Signed-off-by: NLeif Lindholm <leif.lindholm@linaro.org>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Now that we have an efi=debug command line option in the core code, use
this instead of the arm64-specific uefi_debug option.
Signed-off-by: NLeif Lindholm <leif.lindholm@linaro.org>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Our current switch_mm implementation suffers from a number of problems:

  (1) The ASID allocator relies on IPIs to synchronise the CPUs on a
      rollover event

  (2) Because of (1), we cannot allocate ASIDs with interrupts disabled
      and therefore make use of a TIF_SWITCH_MM flag to postpone the
      actual switch to finish_arch_post_lock_switch

  (3) We run context switch with a reserved (invalid) TTBR0 value, even
      though the ASID and pgd are updated atomically

  (4) We take a global spinlock (cpu_asid_lock) during context-switch

  (5) We use h/w broadcast TLB operations when they are not required
      (e.g. in flush_context)

This patch addresses these problems by rewriting the ASID algorithm to
match the bitmap-based arch/arm/ implementation more closely. This in
turn allows us to remove much of the complications surrounding switch_mm,
including the ugly thread flag.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>