Add generic fixmap.h

Many architectures provide an asm/fixmap.h which defines support for
compile-time 'special' virtual mappings which need to be made before
paging_init() has run. This support is also used for early ioremap
on x86. Much of this support is identical across the architectures.
This patch consolidates all of the common bits into asm-generic/fixmap.h
which is intended to be included from arch/*/include/asm/fixmap.h.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
CC: linux-arch@vger.kernel.org
CC: Russell King <linux@arm.linux.org.uk>
CC: linux-arm-kernel@lists.infradead.org
CC: Richard Kuo <rkuo@codeaurora.org>
CC: linux-hexagon@vger.kernel.org
CC: James Hogan <james.hogan@imgtec.com>
CC: linux-metag@vger.kernel.org
CC: Michal Simek <monstr@monstr.eu>
CC: microblaze-uclinux@itee.uq.edu.au
CC: linux-mips@linux-mips.org
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
CC: linuxppc-dev@lists.ozlabs.org
mm: create generic early_ioremap() support

This patch creates a generic implementation of early_ioremap() support
based on the existing x86 implementation. early_ioremp() is useful for
early boot code which needs to temporarily map I/O or memory regions
before normal mapping functions such as ioremap() are available.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
CC: x86@kernel.org
CC: linux-arm-kernel@lists.infradead.org
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Ingo Molnar <mingo@kernel.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
arm64: initialize pgprot info earlier in boot

Presently, paging_init() calls init_mem_pgprot() to initialize pgprot
values used by macros such as PAGE_KERNEL, PAGE_KERNEL_EXEC, etc. The
new fixmap and early_ioremap support also needs to use these macros
before paging_init() is called. This patch moves the init_mem_pgprot()
call out of paging_init() and into setup_arch() so that pgprot_default
gets initialized in time for fixmap and early_ioremap.

Signed-off-by: Mark Salter <msalter@redhat.com>
CC: linux-arm-kernel@lists.infradead.org
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
arm64: add early_ioremap support

Add support for early IO or memory mappings which are needed
before the normal ioremap() is usable. This also adds fixmap
support for permanent fixed mappings such as that used by the
earlyprintk device register region.

Signed-off-by: Mark Salter <msalter@redhat.com>
CC: linux-arm-kernel@lists.infradead.org
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
efi-stub.txt updates for ARM

Update efi-stub.txt documentation to be more general
and not x86 specific.  Add ARM only "dtb=" command
line option description.

Signed-off-by: Roy Franz <roy.franz@linaro.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
Add shared printk wrapper for consistent prefixing

Add a wrapper for printk to standardize the prefix for informational and
error messages from the EFI stub.

Signed-off-by: Roy Franz <roy.franz@linaro.org>
Add helper function to get and convert EFI command line

Add an EFI stub helper function to retrieve the EFI command line using
the LOADED_IMAGE_PROTOCOL, and convert it to ASCII.  This function will
be shared by the various EFI stub implementations.

Signed-off-by: Roy Franz <roy.franz@linaro.org>
Add shared FDT related functions for ARM/ARM64

Both ARM and ARM64 stubs will update the device tree that they pass to
the kernel.  In both cases they primarily need to add the same UEFI
related information, so the function can be shared.  Create a new FDT
related file for this to avoid use of architecture #ifdefs in
efi-stub-helper.c.

Signed-off-by: Roy Franz <roy.franz@linaro.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
efi: create memory map iteration helper

There are a lot of places in the kernel which iterate through an
EFI memory map. Most of these places use essentially the same
for-loop code. This patch adds a for_each_efi_memory_desc()
helper to clean up all of the existing duplicate code and avoid
more in the future.

Signed-off-by: Mark Salter <msalter@redhat.com>
arm64: Add function to create identity mappings

At boot time, UEFI runtime support needs to call into the UEFI firmware
to switch to a virtual address map. This call must be made with UEFI
memory regions identity mapped. The exisitng early boot code creates
an identity map of kernel text/data but this is not sufficient for UEFI.
This patch adds a create_id_mapping() function which reuses the core
code of create_mapping() used to create the kernel RAM mappings.

Signed-off-by: Mark Salter <msalter@redhat.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
CC: linux-arm-kernel@lists.infradead.org
efi: add helper function to get UEFI params from FDT

ARM and ARM64 architectures use the device tree to pass UEFI parameters
from stub to kernel. These parameters are things known to the stub but
not discoverable by the kernel after the stub calls ExitBootSerives().
There is a helper function in:

   drivers/firmware/efi/fdt.c

which the stub uses to add the UEFI parameters to the device tree.
This patch adds a complimentary helper function which UEFI runtime
support may use to retrieve the parameters from the device tree.
If an architecture wants to use this helper, it should select
CONFIG_UEFI_PARAMS_FROM_FDT.

Signed-off-by: Mark Salter <msalter@redhat.com>
arm64: add EFI stub

This patch adds PE/COFF header fields to the start of the Image
so that it appears as an EFI application to EFI firmware. An EFI
stub is included to allow direct booting of the kernel Image. Due
to EFI firmware limitations, only little endian kernels with 4K
page sizes are supported at this time. Support in the COFF header
for signed images was provided by Ard Biesheuvel.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
doc: arm64: add description of EFI stub support

Add explanation of arm64 EFI stub and kernel image header changes
needed to masquerade as a PE/COFF application.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
CC: linux-doc@vger.kernel.org
CC: Rob Landley <rob@landley.net>
arm64: add EFI runtime services

This patch adds EFI runtime support for arm64. The runtime support allows
the kernel to access various EFI runtime services provided by EFI firmware.
Things like reboot, real time clock, EFI boot variables, and others.

Signed-off-by: Mark Salter <msalter@redhat.com>
get DT from configuration table
arm64: efi: add support for FDT in system table

UEFI firmware or secondary UEFI boot loaders may install a device
tree in the UEFI system table. This patch looks for a device tree
in the system table and uses it if found. If not found, the current
method of parsing command line for dtb= parameter is used.

Signed-off-by: Mark Salter <msalter@redhat.com>
arm64: efi-stub: cmdline hack

Some UEFI firmware is broken and doesn't pass a command line
via loaded image protocol in some boot scenarios. This is
only a problem when boot directly from the UEFI firmware (no
secondary loader such as grub). This patch is a convenience
hack to work around the problem. It is not intended for upstream
and is purely temporary.

Signed-off-by: Mark Salter <msalter@redhat.com>