current_stack_frame() doesn't return the stack pointer, but the
caller's stack frame. See commit bfe9a2cfe91a ("powerpc: Reimplement
__get_SP() as a function not a define") and commit
acf620ecf56c ("powerpc: Rename __get_SP() to current_stack_pointer()")
for details.

In some cases this is overkill or incorrect, as it doesn't return the
current value of r1.

So add a current_stack_pointer register global to get the value of r1
directly.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Split out of other patch, tweak change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200220115141.2707-2-mpe@ellerman.id.au

current_stack_pointer(), which was called __get_SP(), used to just
return the value in r1.

But that caused problems in some cases, so it was turned into a
function in commit bfe9a2cfe91a ("powerpc: Reimplement __get_SP() as a
function not a define").

Because it's a function in a separate compilation unit to all its
callers, it has the effect of causing a stack frame to be created, and
then returns the address of that frame. This is good in some cases
like those described in the above commit, but in other cases it's
overkill, we just need to know what stack page we're on.

On some other arches current_stack_pointer is just a register global
giving the stack pointer, and we'd like to do that too. So rename our
current_stack_pointer() to current_stack_frame() to make that
possible.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Link: https://lore.kernel.org/r/20200220115141.2707-1-mpe@ellerman.id.au

Pull powerpc updates from Michael Ellerman:
 "Highlights:

   - Infrastructure for secure boot on some bare metal Power9 machines.
     The firmware support is still in development, so the code here
     won't actually activate secure boot on any existing systems.

   - A change to xmon (our crash handler / pseudo-debugger) to restrict
     it to read-only mode when the kernel is lockdown'ed, otherwise it's
     trivial to drop into xmon and modify kernel data, such as the
     lockdown state.

   - Support for KASLR on 32-bit BookE machines (Freescale / NXP).

   - Fixes for our flush_icache_range() and __kernel_sync_dicache()
     (VDSO) to work with memory ranges >4GB.

   - Some reworks of the pseries CMM (Cooperative Memory Management)
     driver to make it behave more like other balloon drivers and enable
     some cleanups of generic mm code.

   - A series of fixes to our hardware breakpoint support to properly
     handle unaligned watchpoint addresses.

  Plus a bunch of other smaller improvements, fixes and cleanups.

  Thanks to: Alastair D'Silva, Andrew Donnellan, Aneesh Kumar K.V,
  Anthony Steinhauser, Cédric Le Goater, Chris Packham, Chris Smart,
  Christophe Leroy, Christopher M. Riedl, Christoph Hellwig, Claudio
  Carvalho, Daniel Axtens, David Hildenbrand, Deb McLemore, Diana
  Craciun, Eric Richter, Geert Uytterhoeven, Greg Kroah-Hartman, Greg
  Kurz, Gustavo L. F. Walbon, Hari Bathini, Harish, Jason Yan, Krzysztof
  Kozlowski, Leonardo Bras, Mathieu Malaterre, Mauro S. M. Rodrigues,
  Michal Suchanek, Mimi Zohar, Nathan Chancellor, Nathan Lynch, Nayna
  Jain, Nick Desaulniers, Oliver O'Halloran, Qian Cai, Rasmus Villemoes,
  Ravi Bangoria, Sam Bobroff, Santosh Sivaraj, Scott Wood, Thomas Huth,
  Tyrel Datwyler, Vaibhav Jain, Valentin Longchamp, YueHaibing"

* tag 'powerpc-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (144 commits)
  powerpc/fixmap: fix crash with HIGHMEM
  x86/efi: remove unused variables
  powerpc: Define arch_is_kernel_initmem_freed() for lockdep
  powerpc/prom_init: Use -ffreestanding to avoid a reference to bcmp
  powerpc: Avoid clang warnings around setjmp and longjmp
  powerpc: Don't add -mabi= flags when building with Clang
  powerpc: Fix Kconfig indentation
  powerpc/fixmap: don't clear fixmap area in paging_init()
  selftests/powerpc: spectre_v2 test must be built 64-bit
  powerpc/powernv: Disable native PCIe port management
  powerpc/kexec: Move kexec files into a dedicated subdir.
  powerpc/32: Split kexec low level code out of misc_32.S
  powerpc/sysdev: drop simple gpio
  powerpc/83xx: map IMMR with a BAT.
  powerpc/32s: automatically allocate BAT in setbat()
  powerpc/ioremap: warn on early use of ioremap()
  powerpc: Add support for GENERIC_EARLY_IOREMAP
  powerpc/fixmap: Use __fix_to_virt() instead of fix_to_virt()
  powerpc/8xx: use the fixmapped IMMR in cpm_reset()
  powerpc/8xx: add __init to cpm1 init functions
  ...

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

Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Currently the reserved bits of the Processor Compatibility
Register (PCR) are cleared as per the Programming Note in Section
1.3.3 of version 3.0B of the Power ISA. This causes all new
architecture features to be made available when running on newer
processors with new architecture features added to the PCR as bits
must be set to disable a given feature.

For example to disable new features added as part of Version 2.07 of
the ISA the corresponding bit in the PCR needs to be set.

As new processor features generally require explicit kernel support
they should be disabled until such support is implemented. Therefore
kernels should set all unknown/reserved bits in the PCR such that any
new architecture features which the kernel does not currently know
about get disabled.

An update is planned to the ISA to clarify that the PCR is an
exception to the Programming Note on reserved bits in Section 1.3.3.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190917004605.22471-2-alistair@popple.id.au

Commit 388cc6e133132 ("KVM: PPC: Book3S HV: Support POWER6
compatibility mode on POWER7") introduced new macros defining the PCR
bits. When used from assembly files these definitions lead to build
errors using older versions of binutils that don't support the 'ul'
suffix. This fixes the build errors by updating the definitions to use
the __MASK() macro which selects the appropriate suffix.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190917004605.22471-1-alistair@popple.id.au

Protected Execution Facility (PEF) is an architectural change for
POWER 9 that enables Secure Virtual Machines (SVMs). When enabled,
PEF adds a new higher privileged mode, called Ultravisor mode, to
POWER architecture.

The hardware changes include the following:

  * There is a new bit in the MSR that determines whether the current
    process is running in secure mode, MSR(S) bit 41. MSR(S)=1, process
    is in secure mode, MSR(s)=0 process is in normal mode.

  * The MSR(S) bit can only be set by the Ultravisor.

  * HRFID cannot be used to set the MSR(S) bit. If the hypervisor needs
    to return to a SVM it must use an ultracall. It can determine if
    the VM it is returning to is secure.

  * The privilege of a process is now determined by three MSR bits,
    MSR(S, HV, PR). In each of the tables below the modes are listed
    from least privilege to highest privilege. The higher privilege
    modes can access all the resources of the lower privilege modes.

    **Secure Mode MSR Settings**

       +---+---+---+---------------+
       | S | HV| PR|Privilege      |
       +===+===+===+===============+
       | 1 | 0 | 1 | Problem       |
       +---+---+---+---------------+
       | 1 | 0 | 0 | Privileged(OS)|
       +---+---+---+---------------+
       | 1 | 1 | 0 | Ultravisor    |
       +---+---+---+---------------+
       | 1 | 1 | 1 | Reserved      |
       +---+---+---+---------------+

    **Normal Mode MSR Settings**

       +---+---+---+---------------+
       | S | HV| PR|Privilege      |
       +===+===+===+===============+
       | 0 | 0 | 1 | Problem       |
       +---+---+---+---------------+
       | 0 | 0 | 0 | Privileged(OS)|
       +---+---+---+---------------+
       | 0 | 1 | 0 | Hypervisor    |
       +---+---+---+---------------+
       | 0 | 1 | 1 | Problem (HV)  |
       +---+---+---+---------------+

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[ cclaudio: Update the commit message ]
Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820021326.6884-7-bauerman@linux.ibm.com