Remove an unused local variable from head.S.  It seems this was never
used even from the initial commit
9703d9d7f77ce129621f7d80a844822e2daa7008 (arm64: Kernel booting and
initialisation), and is a left over from a previous implementation
of __calc_phys_offset.

Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

When booting via UEFI, the kernel Image is loaded at a 4 kB boundary and
the embedded EFI stub is executed in place. The EFI stub relocates the
Image to reside TEXT_OFFSET bytes above a 2 MB boundary, and jumps into
the kernel proper.

In AArch64, PC relative symbol references are emitted using adrp/add or
adrp/ldr pairs, where the offset into a 4 kB page is resolved using a
separate :lo12: relocation. This implicitly assumes that the code will
always be executed at the same relative offset with respect to a 4 kB
boundary, or the references will point to the wrong address.

This means we should link the kernel at a 4 kB aligned base address in
order to remain compatible with the base address the UEFI loader uses
when doing the initial load of Image. So update the code that generates
TEXT_OFFSET to choose a multiple of 4 kB.

At the same time, update the code so it chooses from the interval [0..2MB)
as the author originally intended.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

GICv3 introduces new system registers accessible with the full msr/mrs
syntax (e.g. mrs x0, Sop0_op1_CRm_CRn_op2). However, only recent
binutils understand the new syntax. This patch introduces msr_s/mrs_s
assembly macros which generate the equivalent instructions above and
converts the existing GICv3 code (both drivers/irqchip/ and
arch/arm64/kernel/).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Olof Johansson <olof@lixom.net>
Tested-by: Olof Johansson <olof@lixom.net>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>

* tag 'deps-irqchip-gic-3.17' of git://git.infradead.org/users/jcooper/linux:
  irqchip: gic-v3: Initial support for GICv3
  irqchip: gic: Move some bits of GICv2 to a library-type file

Conflicts:
	arch/arm64/Kconfig

This patch allows support for 3 levels of page tables with 64KB page
configuration allowing 48-bit VA space. The pgd is no longer a full
PAGE_SIZE (PTRS_PER_PGD is 64) and (swapper|idmap)_pg_dir are not fully
populated (pgd_alloc falls back to kzalloc).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Jungseok Lee <jungseoklee85@gmail.com>

This patch adds a create_table_entry macro which is used to populate pgd
and pud entries, also reducing the number of arguments for
create_pgd_entry.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Jungseok Lee <jungseoklee85@gmail.com>

Rather than having several Kconfig options, define int
ARM64_PGTABLE_LEVELS which will be also useful in converting some of the
pgtable macros.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Jungseok Lee <jungseoklee85@gmail.com>

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>

The early_ioremap_init() function already handles fixmap pte
initialisation, so upgrade this to cover all of pud/pmd/pte and remove
one page from swapper_pg_dir.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Jungseok Lee <jungseoklee85@gmail.com>

The arm64 Image header contains a text_offset field which bootloaders
are supposed to read to determine the offset (from a 2MB aligned "start
of memory" per booting.txt) at which to load the kernel. The offset is
not well respected by bootloaders at present, and due to the lack of
variation there is little incentive to support it. This is unfortunate
for the sake of future kernels where we may wish to vary the text offset
(even zeroing it).

This patch adds options to arm64 to enable fuzz-testing of text_offset.
CONFIG_ARM64_RANDOMIZE_TEXT_OFFSET forces the text offset to a random
16-byte aligned value value in the range [0..2MB) upon a build of the
kernel. It is recommended that distribution kernels enable randomization
to test bootloaders such that any compliance issues can be fixed early.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Tom Rini <trini@ti.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>