Under certain circumstances, we hit a warning in lockdep_register_key:

        if (WARN_ON_ONCE(static_obj(key)))
                return;

This occurs when the key falls into initmem that has since been freed
and can now be reused. This has been observed on boot, and under
memory pressure.

Define arch_is_kernel_initmem_freed(), which allows lockdep to
correctly identify this memory as dynamic.

This fixes a bug picked up by the powerpc64 syzkaller instance where
we hit the WARN via alloc_netdev_mqs.
Reported-by: Qian Cai <cai@lca.pw>
Reported-by: ppc syzbot c/o Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Link: https://lore.kernel.org/r/87lfs4f7d6.fsf@dja-thinkpad.axtens.net

LLVM revision r374662 gives LLVM the ability to convert certain loops
into a reference to bcmp as an optimization; this breaks
prom_init_check.sh:

    CALL    arch/powerpc/kernel/prom_init_check.sh
  Error: External symbol 'bcmp' referenced from prom_init.c
  make[2]: *** [arch/powerpc/kernel/Makefile:196: prom_init_check] Error 1

bcmp is defined in lib/string.c as a wrapper for memcmp so this could
be added to the whitelist. However, commit
450e7dd4 ("powerpc/prom_init: don't use string functions from
lib/") copied memcmp as prom_memcmp to avoid KASAN instrumentation so
having bcmp be resolved to regular memcmp would break that assumption.
Furthermore, because the compiler is the one that inserted bcmp, we
cannot provide something like prom_bcmp.

To prevent LLVM from being clever with optimizations like this, use
-ffreestanding to tell LLVM we are not hosted so it is not free to
make transformations like this.
Reviewed-by: Nick Desaulneris <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191119045712.39633-4-natechancellor@gmail.com

Commit aea44714 ("powerpc: Disable -Wbuiltin-requires-header when
setjmp is used") disabled -Wbuiltin-requires-header because of a
warning about the setjmp and longjmp declarations.

r367387 in clang added another diagnostic around this, complaining
that there is no jmp_buf declaration.

  In file included from ../arch/powerpc/xmon/xmon.c:47:
  ../arch/powerpc/include/asm/setjmp.h:10:13: error: declaration of
  built-in function 'setjmp' requires the declaration of the 'jmp_buf'
  type, commonly provided in the header <setjmp.h>.
  [-Werror,-Wincomplete-setjmp-declaration]
  extern long setjmp(long *);
              ^
  ../arch/powerpc/include/asm/setjmp.h:11:13: error: declaration of
  built-in function 'longjmp' requires the declaration of the 'jmp_buf'
  type, commonly provided in the header <setjmp.h>.
  [-Werror,-Wincomplete-setjmp-declaration]
  extern void longjmp(long *, long);
              ^
  2 errors generated.

We are not using the standard library's longjmp/setjmp implementations
for obvious reasons; make this clear to clang by using -ffreestanding
on these files.

Cc: stable@vger.kernel.org # 4.14+
Suggested-by: Segher Boessenkool <segher@kernel.crashing.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191119045712.39633-3-natechancellor@gmail.com

When building pseries_defconfig, building vdso32 errors out:

  error: unknown target ABI 'elfv1'

This happens because -m32 in clang changes the target to 32-bit,
which does not allow the ABI to be changed.

Commit 4dc831aa ("powerpc: Fix compiling a BE kernel with a
powerpc64le toolchain") added these flags to fix building big endian
kernels with a little endian GCC.

Clang doesn't need -mabi because the target triple controls the
default value. -mlittle-endian and -mbig-endian manipulate the triple
into either powerpc64-* or powerpc64le-*, which properly sets the
default ABI.

Adding a debug print out in the PPC64TargetInfo constructor after line
383 above shows this:

  $ echo | ./clang -E --target=powerpc64-linux -mbig-endian -o /dev/null -
  Default ABI: elfv1

  $ echo | ./clang -E --target=powerpc64-linux -mlittle-endian -o /dev/null -
  Default ABI: elfv2

  $ echo | ./clang -E --target=powerpc64le-linux -mbig-endian -o /dev/null -
  Default ABI: elfv1

  $ echo | ./clang -E --target=powerpc64le-linux -mlittle-endian -o /dev/null -
  Default ABI: elfv2

Don't specify -mabi when building with clang to avoid the build error
with -m32 and not change any code generation.

-mcall-aixdesc is not an implemented flag in clang so it can be safely
excluded as well, see commit 238abecd ("powerpc: Don't use gcc
specific options on clang").

pseries_defconfig successfully builds after this patch and
powernv_defconfig and ppc44x_defconfig don't regress.
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
[mpe: Trim clang links in change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191119045712.39633-2-natechancellor@gmail.com

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
	$ sed -e 's/^        /\t/' -i */Kconfig
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1574306461-7646-1-git-send-email-krzk@kernel.org

fixmap is intended to map things permanently like the IMMR region on
FSL SOC (8xx, 83xx, ...), so don't clear it when initialising paging()
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/41c99bc06394a6bc2888631cb98a3ed2ae281ddb.1568295907.git.christophe.leroy@c-s.fr

The spectre_v2 test must be built 64-bit, it includes hand-written asm
that is 64-bit only, and segfaults if built 32-bit.

Fixes: c790c3d2 ("selftests/powerpc: Add a test of spectre_v2 mitigations")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191120023924.13130-1-mpe@ellerman.id.au

On PowerNV the PCIe topology is (currently) managed by the powernv platform
code in Linux in cooperation with the platform firmware. Linux's native
PCIe port service drivers operate independently of both and this can cause
problems.

The main issue is that the portbus driver will conflict with the platform
specific hotplug driver (pnv_php) over ownership of the MSI used to notify
the host when a hotplug event occurs. The portbus driver claims this MSI on
behalf of the individual port services because the same interrupt is used
for hotplug events, PMEs (on root ports), and link bandwidth change
notifications. The portbus driver will always claim the interrupt even if
the individual port service drivers, such as pciehp, are compiled out.

The second, bigger, problem is that the hotplug port service driver
fundamentally does not work on PowerNV. The platform assumes that all
PCI devices have a corresponding arch-specific handle derived from the DT
node for the device (pci_dn) and without one the platform will not allow
a PCI device to be enabled. This problem is largely due to historical
baggage, but it can't be resolved without significant re-factoring of the
platform PCI support.

We can fix these problems in the interim by setting the
"pcie_ports_disabled" flag during platform initialisation. The flag
indicates the platform owns the PCIe ports which stops the portbus driver
from being registered.

This does have the side effect of disabling all port services drivers
that is: AER, PME, BW notifications, hotplug, and DPC. However, this is
not a huge disadvantage on PowerNV since these services are either unused
or handled through other means.

Fixes: 66725152 ("PCI/hotplug: PowerPC PowerNV PCI hotplug driver")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191118065553.30362-1-oohall@gmail.com

arch/powerpc/kernel/ contains 8 files dedicated to kexec.

Move them into a dedicated subdirectory.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Move to a/p/kexec, drop the 'machine' naming and use 'core' instead]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/afbef97ec6a978574a5cf91a4441000e0a9da42a.1572351221.git.christophe.leroy@c-s.fr

Almost half of misc_32.S is dedicated to kexec.
That's the relocation function for kexec.

Drop it into a dedicated kexec_relocate_32.S
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e235973a1198195763afd3b6baffa548a83f4611.1572351221.git.christophe.leroy@c-s.fr

There is a config item CONFIG_SIMPLE_GPIO which
provides simple memory mapped GPIOs specific to powerpc.

However, the only platform which selects this option is
mpc5200, and this platform doesn't use it.

There are three boards calling simple_gpiochip_init(), but
as they don't select CONFIG_SIMPLE_GPIO, this is just a nop.

Simple_gpio is just redundant with the generic MMIO GPIO
driver which can be found in driver/gpio/ and selected via
CONFIG_GPIO_GENERIC_PLATFORM, so drop simple_gpio driver.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bf930402613b41b42d0441b784e0cc43fc18d1fb.1572529632.git.christophe.leroy@c-s.fr

On mpc83xx with a QE, IMMR is 2Mbytes and aligned on 2Mbytes boundarie.
On mpc83xx without a QE, IMMR is 1Mbyte and 1Mbyte aligned.

Each driver will map a part of it to access the registers it needs.
Some drivers will map the same part of IMMR as other drivers.

In order to reduce TLB misses, map the full IMMR with a BAT. If it is
2Mbytes aligned, map 2Mbytes. If there is no QE, the upper part will
remain unused, but it doesn't harm as it is mapped as guarded memory.

When the IMMR is not aligned on a 2Mbytes boundarie, only map 1Mbyte.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/269a00951328fb6fa1be2fa3cbc76c19745019b7.1568665466.git.christophe.leroy@c-s.fr

If no BAT is given to setbat(), select an available BAT.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a212bd36fbd6179e0929b6c727febc35132ac25c.1568665466.git.christophe.leroy@c-s.fr

Powerpc now has EARLY_IOREMAP.

Next step is to convert all early users of ioremap() to
early_ioremap().

Add a warning to help locate those users.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b4f03a68ee8e68773c8973d74ec35f9c82c72871.1568295907.git.christophe.leroy@c-s.fr

Add support for GENERIC_EARLY_IOREMAP.

Let's define 16 slots of 256Kbytes each for early ioremap.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/412c7eaa6a373d8f82a3c3ee01e6a65a1a6589de.1568295907.git.christophe.leroy@c-s.fr

Modify back __set_fixmap() to using __fix_to_virt() instead
of fix_to_virt() otherwise the following happens because it
seems GCC doesn't see idx as a builtin const.

  CC      mm/early_ioremap.o
In file included from ./include/linux/kernel.h:11:0,
                 from mm/early_ioremap.c:11:
In function ‘fix_to_virt’,
    inlined from ‘__set_fixmap’ at ./arch/powerpc/include/asm/fixmap.h:87:2,
    inlined from ‘__early_ioremap’ at mm/early_ioremap.c:156:4:
./include/linux/compiler.h:350:38: error: call to ‘__compiletime_assert_32’ declared with attribute error: BUILD_BUG_ON failed: idx >= __end_of_fixed_addresses
  _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
                                      ^
./include/linux/compiler.h:331:4: note: in definition of macro ‘__compiletime_assert’
    prefix ## suffix();    \
    ^
./include/linux/compiler.h:350:2: note: in expansion of macro ‘_compiletime_assert’
  _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
  ^
./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
 #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
                                     ^
./include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
  BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
  ^
./include/asm-generic/fixmap.h:32:2: note: in expansion of macro ‘BUILD_BUG_ON’
  BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
  ^
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Fixes: 4cfac2f9 ("powerpc/mm: Simplify __set_fixmap()")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f4984c615f90caa3277775a68849afeea846850d.1568295907.git.christophe.leroy@c-s.fr

Since commit f86ef74e ("powerpc/8xx: Fix vaddr for IMMR early
remap"), the IMMR area has been mapped at startup with fixmap.

Use that fixmap directly instead of calling ioremap(), this
avoids calling ioremap() early before the slab is available.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f816ccdbd15b97cf43c5a8c7cc8dfa8db58ff036.1568294935.git.christophe.leroy@c-s.fr

Functions cpm1_clk_setup(), cpm1_set_pin(), cpm_pic_init() and
mpc8xx_pic_init() are only called from __init functions, so mark
them __init as well.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c27168ef054f3a52edcf0ff91652700d53b3e32d.1568294563.git.christophe.leroy@c-s.fr

SET_MSR_EE() is just use in this file and doesn't provide
any added value compared to mtmsr(). Drop it.

Add a wrtee() inline function to use wrtee/wrteei insn.

Replace #ifdefs by IS_ENABLED()
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a28a20514d5f6df9629c1a117b667e48c4272736.1567068137.git.christophe.leroy@c-s.fr

Most 8xx registers have specific names, so just include
reg_8xx.h all the time in reg.h in order to have them defined
even when CONFIG_PPC_8xx is not selected. This will avoid
the need for #ifdefs in C code.

Guard SPRN_ICTRL in an #ifdef CONFIG_PPC_8xx as this register
has same name but different meaning and different spr number as
another register in the mpc7450.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/dd82934ad91aab607d0eb7e626c14e6ac0d654eb.1567068137.git.christophe.leroy@c-s.fr

mftb() includes a feature fixup for CELL ppc.

Use ASM_FTR_IFSET() macro instead of opencoding the setup
of the fixup sections.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ac19713826fa55e9e7bfe3100c5a7b1712ab9526.1566999711.git.christophe.leroy@c-s.fr

Commit d2f15e09 ("powerpc/32: always populate page tables for
Abatron BDI.") wrongly sets page tables for any PPC32 for using BDI,
and does't update them after init (remove RX on init section, set
text and rodata read-only)

Only the 8xx requires page tables to be populated for using the BDI.
They also need to be populated in order to see the mappings in
/sys/kernel/debug/kernel_page_tables

On BOOK3S_32, pages that are not mapped by page tables are mapped
by BATs. The BDI knows BATs and they can be viewed in
/sys/kernel/debug/powerpc/block_address_translation

Only set pagetables for RAM and IMMR on the 8xx and properly update
them at the end of init.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c8610942203e0d93fcb02ad20c57edd3adb4c9d3.1566554029.git.christophe.leroy@c-s.fr

DSISR (or ESR on some CPUs) has a bit to tell if the fault is due to a
read or a write.

Display it.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4f88d7e6fda53b5f80a71040ab400242f6c8cb93.1566400889.git.christophe.leroy@c-s.fr

powerpc always selects CONFIG_MMU and CONFIG_MMU is not checked
anywhere else in powerpc code.

Drop the #ifdef and the alternative part of is_ioremap_addr()

Fixes: 9bd3bb67 ("mm/nvdimm: add is_ioremap_addr and use that to check ioremap address")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/de395e444fb8dd7a6365c3314d78e15ebb3d7d1b.1566382245.git.christophe.leroy@c-s.fr

BUG(), WARN() and friends are using a similar inline assembly to
implement various traps with various flags.

Lets refactor via a new BUG_ENTRY() macro.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c19a82b37677ace0eebb0dc8c2120373c29c8dd1.1566219503.git.christophe.leroy@c-s.fr

Merge changes from Scott:
  Includes a couple of device tree fixes, a spelling fix, and leftover
  code cleanup.

This removes the warnings about the fact that the 4 pci bridges (i.e.
the 4 pci hosts) don't have any ranges.
Signed-off-by: Valentin Longchamp <valentin@longchamp.me>
Signed-off-by: Scott Wood <oss@buserror.net>

Caching dates is never a good idea ;-)

Fixes: e7affb1d ("powerpc/cache: add cache flush operation for various e500")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Scott Wood <oss@buserror.net>

Since commit 302c059f (QE: use subsys_initcall to init qe),
mpc85xx_qe_init() has done nothing apart from possibly emitting a
pr_err(). As part of reducing the amount of QE-related code in
arch/powerpc/ (and eventually support QE on other architectures),
remove this low-hanging fruit.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Scott Wood <oss@buserror.net>

Change all phy-connection-type properties to phy-mode that are better
supported by the fman driver.

Use the more readable fixed-link node for the 2 sgmii links.

Change the RGMII link to rgmii-id as the clock delays are added by the
phy.
Signed-off-by: Valentin Longchamp <valentin@longchamp.me>
Acked-by: Madalin Bucur <madalin.bucur@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>

On older distributions like Sles12SP5 gcc does not recognize
-no-pie option making the powerpc selftests build to fail

Fixes the following:
gcc: error: unrecognized command line option ‘-no-pie’
Signed-off-by: Harish <harish@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191113094219.14946-1-harish@linux.ibm.com

This is a slight rebase of Scott's next branch, which contained the
KASLR support for book3e 32-bit, to squash in a couple of small fixes.

See the	original pull request:
  https://lore.kernel.org/r/20191022232155.GA26174@home.buserror.net

Add document to explain how we implement KASLR for fsl_booke32.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Scott Wood <oss@buserror.net>
[mpe: Add it to the index as well]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Like all other architectures such as x86 or arm64, include KASLR offset
in VMCOREINFO ELF notes to assist in debugging. After this, we can use
crash --kaslr option to parse vmcore generated from a kaslr kernel.

Note: The crash tool needs to support --kaslr too.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

When kaslr is enabled, the kernel offset is different for every boot.
This brings some difficult to debug the kernel. Dump out the kernel
offset when panic so that we can easily debug the kernel.

This code is derived from x86/arm64 which has similar functionality.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

One may want to disable kaslr when boot, so provide a cmdline parameter
'nokaslr' to support this.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The original kernel still exists in the memory, clear it now.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

After we have the basic support of relocate the kernel in some
appropriate place, we can start to randomize the offset now.

Entropy is derived from the banner and timer, which will change every
build and boot. This not so much safe so additionally the bootloader may
pass entropy via the /chosen/kaslr-seed node in device tree.

We will use the first 512M of the low memory to randomize the kernel
image. The memory will be split in 64M zones. We will use the lower 8
bit of the entropy to decide the index of the 64M zone. Then we chose a
16K aligned offset inside the 64M zone to put the kernel in.

We also check if we will overlap with some areas like the dtb area, the
initrd area or the crashkernel area. If we cannot find a proper area,
kaslr will be disabled and boot from the original kernel.

Some pieces of code are derived from arch/x86/boot/compressed/kaslr.c or
arch/arm64/kernel/kaslr.c such as rotate_xor(). Credit goes to Kees and
Ard.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This patch add support to boot kernel from places other than KERNELBASE.
Since CONFIG_RELOCATABLE has already supported, what we need to do is
map or copy kernel to a proper place and relocate. Freescale Book-E
parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1
entries are not suitable to map the kernel directly in a randomized
region, so we chose to copy the kernel to a proper place and restart to
relocate.

The offset of the kernel was not randomized yet(a fixed 64M is set). We
will randomize it in the next patch.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
[mpe: Use PTRRELOC() in early_init()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add a new helper reloc_kernel_entry() to jump back to the start of the
new kernel. After we put the new kernel in a randomized place we can use
this new helper to enter the kernel and begin to relocate again.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>