Pull powerpc fix from Michael Ellerman:
 "One fix from Paul: we can not use the radix MMU under a hypervisor for
  now.

  Although the code checked if the processor supports radix, that is not
  sufficient"

* tag 'powerpc-4.10-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64: Disable use of radix under a hypervisor

Currently, if the kernel is running on a POWER9 processor under a
hypervisor, it may try to use the radix MMU even though it doesn't have
the necessary code to do so (it doesn't negotiate use of radix, and it
doesn't do the H_REGISTER_PROC_TBL hcall).  If the hypervisor supports
both radix and HPT, then it will set up the guest to use HPT (since the
guest doesn't request radix in the CAS call), but if the radix feature
bit is set in the ibm,pa-features property (which is valid, since
ibm,pa-features is defined to represent the capabilities of the
processor) the guest will try to use radix, resulting in a crash when
it turns the MMU on.

This makes the minimal fix for the current code, which is to disable
radix unless we are running in hypervisor mode.

Fixes: 2bfd65e45e87 ("powerpc/mm/radix: Add radix callbacks for early init routines")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Pull powerpc fixes friom Michael Ellerman:
 "Apologies for the late pull request, but Ben has been busy finding bugs.

   - Userspace was semi-randomly segfaulting on radix due to us
     incorrectly handling a fault triggered by autonuma, caused by a
     patch we merged earlier in v4.10 to prevent the kernel executing
     userspace.

   - We weren't marking host IPIs properly for KVM in the OPAL ICP
     backend.

   - The ERAT flushing on radix was missing an isync and was incorrectly
     marked as DD1 only.

   - The powernv CPU hotplug code was missing a wakeup type and failing
     to flush the interrupt correctly when using OPAL ICP

  Thanks to Benjamin Herrenschmidt"

* tag 'powerpc-4.10-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/powernv: Properly set "host-ipi" on IPIs
  powerpc/powernv: Fix CPU hotplug to handle waking on HVI
  powerpc/mm/radix: Update ERAT flushes when invalidating TLB
  powerpc/mm: Fix spurrious segfaults on radix with autonuma

Otherwise KVM will fail to pass them through to the host

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The IPIs come in as HVI not EE, so we need to test the appropriate
SRR1 bits. The encoding is such that it won't have false positives
on P7 and P8 so we can just test it like that. We also need to handle
the icp-opal variant of the flush.

Fixes: d74361881f0d ("powerpc/xics: Add ICP OPAL backend")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Three tiny changes to the ERAT flushing logic: First don't make
it depend on DD1. It hasn't been decided yet but we might run
DD2 in a mode that also requires explicit flushes for performance
reasons so make it unconditional. We also add a missing isync, and
finally remove the flush from _tlbiel_va as it is only necessary
for congruence-class invalidations (PID, LPID and full TLB), not
targetted invalidations.

Fixes: 96ed1fe511a8 ("powerpc/mm/radix: Invalidate ERAT on tlbiel for POWER9 DD1")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

When autonuma (Automatic NUMA balancing) marks a PTE inaccessible it
clears all the protection bits but leave the PTE valid.

With the Radix MMU, an attempt at executing from such a PTE will
take a fault with bit 35 of SRR1 set "SRR1_ISI_N_OR_G".

It is thus incorrect to treat all such faults as errors. We should
pass them to handle_mm_fault() for autonuma to deal with. The case
of pages that are really not executable is handled by the existing
test for VM_EXEC further down.

That leaves us with catching the kernel attempts at executing user
pages. We can catch that earlier, even before we do find_vma.

It is never valid on powerpc for the kernel to take an exec fault
to begin with. So fold that test with the existing test for the
kernel faulting on kernel addresses to bail out early.

Fixes: 1d18ad026844 ("powerpc/mm: Detect instruction fetch denied and report")
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Pull powerpc fixes from Michael Ellerman:
 "The main change is we're reverting the initial stack protector support
  we merged this cycle. It turns out to not work on toolchains built
  with libc support, and fixing it will be need to wait for another
  release.

  And the rest are all fairly minor:

   - Some pasemi machines were not booting due to a missing error check
     in prom_find_boot_cpu()

   - In EEH we were checking a pointer rather than the bool it pointed
     to

   - The clang build was broken by a BUILD_BUG_ON() we added.

   - The radix (Power9 only) version of map_kernel_page() was broken if
     our memory size was a multiple of 2MB, which it generally isn't

  Thanks to: Darren Stevens, Gavin Shan, Reza Arbab"

* tag 'powerpc-4.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm: Use the correct pointer when setting a 2MB pte
  powerpc: Fix build failure with clang due to BUILD_BUG_ON()
  powerpc: Revert the initial stack protector support
  powerpc/eeh: Fix wrong flag passed to eeh_unfreeze_pe()
  powerpc: Add missing error check to prom_find_boot_cpu()

The modversion symbol CRCs are emitted as ELF symbols, which allows us
to easily populate the kcrctab sections by relying on the linker to
associate each kcrctab slot with the correct value.

This has a couple of downsides:

 - Given that the CRCs are treated as memory addresses, we waste 4 bytes
   for each CRC on 64 bit architectures,

 - On architectures that support runtime relocation, a R_<arch>_RELATIVE
   relocation entry is emitted for each CRC value, which identifies it
   as a quantity that requires fixing up based on the actual runtime
   load offset of the kernel. This results in corrupted CRCs unless we
   explicitly undo the fixup (and this is currently being handled in the
   core module code)

 - Such runtime relocation entries take up 24 bytes of __init space
   each, resulting in a x8 overhead in [uncompressed] kernel size for
   CRCs.

Switching to explicit 32 bit values on 64 bit architectures fixes most
of these issues, given that 32 bit values are not treated as quantities
that require fixing up based on the actual runtime load offset.  Note
that on some ELF64 architectures [such as PPC64], these 32-bit values
are still emitted as [absolute] runtime relocatable quantities, even if
the value resolves to a build time constant.  Since relative relocations
are always resolved at build time, this patch enables MODULE_REL_CRCS on
powerpc when CONFIG_RELOCATABLE=y, which turns the absolute CRC
references into relative references into .rodata where the actual CRC
value is stored.

So redefine all CRC fields and variables as u32, and redefine the
__CRC_SYMBOL() macro for 64 bit builds to emit the CRC reference using
inline assembler (which is necessary since 64-bit C code cannot use
32-bit types to hold memory addresses, even if they are ultimately
resolved using values that do not exceed 0xffffffff).  To avoid
potential problems with legacy 32-bit architectures using legacy
toolchains, the equivalent C definition of the kcrctab entry is retained
for 32-bit architectures.

Note that this mostly reverts commit d4703aefdbc8 ("module: handle ppc64
relocating kcrctabs when CONFIG_RELOCATABLE=y")

Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When setting a 2MB pte, radix__map_kernel_page() is using the address

	ptep = (pte_t *)pudp;

Fix this conversion to use pmdp instead. Use pmdp_ptep() to do this
instead of casting the pointer.

Fixes: 2bfd65e45e87 ("powerpc/mm/radix: Add radix callbacks for early init routines")
Cc: stable@vger.kernel.org # v4.7+
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>