POWER9 adds form 1 scoms. The form of the indirection is specified in
the top nibble of the scom address.

Currently we do some (ugly) bit mangling so that we can fit a 64 bit
scom address into the debugfs interface. The current code only shifts
the top bit (indirect bit).

This patch changes it to shift the whole top nibble so that the form
of the indirection is also shifted.

This patch is backwards compatible with older scoms.

(This change isn't required in the arch/powerpc/platforms/powernv/opal-prd.c
scom interface as it passes the whole 64bit scom address without any bit
mangling)

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Currently the code to perform an OPAL call is duplicated between the
normal path and path taken when tracepoints are enabled. There's no
real need for this and combining them makes opal_tracepoint_entry
considerably easier to understand.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Currently the xmon debugger is set only via kernel boot command-line.
It's disabled by default, and can be enabled with "xmon=on" on the
command-line. Also, xmon may be accessed via sysrq mechanism.
But we cannot enable/disable xmon in runtime, it needs kernel reload.

This patch introduces a debugfs entry for xmon, allowing user to query
its current state and change it if desired. Basically, the "xmon" file
to read from/write to is under the debugfs mount point, on powerpc
directory. It's a simple attribute, value 0 meaning xmon is disabled
and value 1 the opposite. Writing these states to the file will take
immediate effect in the debugger.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The xmon parameter nobt was added long time ago, by commit 26c8af5f
("[POWERPC] print backtrace when entering xmon"). The problem that time
was that during a crash in a machine with USB keyboard, xmon wouldn't
respond to commands from the keyboard, so printing the backtrace wouldn't
be possible.

Idea then was to show automatically the backtrace on xmon crash for the
first time it's invoked (if it recovers, next time xmon won't show
backtrace automatically). The nobt parameter was added _only_ to prevent
this automatic trace show. Seems long time ago USB keyboards didn't work
that well!

We don't need this parameter anymore, the feature of auto showing the
backtrace is interesting (imagine a case of auto-reboot script),
so this patch extends the functionality, by always showing the backtrace
automatically when xmon is invoked; it removes the nobt parameter too.

Also, this patch fixes __initdata placement on xmon_early and replaces
__initcall() with modern device_initcall() on sysrq handler.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Once xmon is triggered by sysrq-x, it is enabled always afterwards even
if it is disabled during boot. This will cause a system reset interrupt
fail to dump. So keep xmon in its original state after exit.

We have several ways to set xmon on or off.
1) by a build config CONFIG_XMON_DEFAULT.
2) by a boot cmdline with xmon or xmon=early or xmon=on to enable xmon
and xmon=off to disable xmon. This value will override that in step 1.
3) by a debugfs interface, as proposed in this patchset.
And this value can override those in step 1 and 2.

Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

POWER8 uses bit 36 in SRR1 like POWER9 for i-side machine checks, and
contains several conditions for link timeouts that are not currently
handled.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Move the handling (corrective action) of machine checks to the table
based evaluation.

This changes P7 and P8 ERAT flushing from using SLB flush to using ERAT
flush.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Have machine types define i-side and d-side tables to describe their
machine check encodings, and match entries to evaluate (for reporting)
machine checks.

Functionality is mostly unchanged (tested with a userspace harness), but
it does make a change in that it no longer records DAR as the effective
address for those errors where it is specified to be invalid (which is a
reporting change only).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Use the flush function introduced with the POWER9 machine check handler
for POWER7 and 8, rather than open coding it multiple times in callers.

There is a specific ERAT flush type introduced for POWER9, but the
POWER7-8 ERAT errors continue to do SLB flushing (which also flushes
ERAT), so as not to introduce functional changes with this cleanup
patch.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Print the faulting address of the machine check that may help with
debugging. The effective address reported can be a target memory address
rather than the faulting instruction address.

Fix up a dangling bracket while here.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add declarations for:
  - __mfdcr, __mtdcr (if CONFIG_PPC_DCR_NATIVE=y; through <asm/dcr.h>)
  - switch_mmu_context (if CONFIG_PPC_BOOK3S_64=n; through <asm/mmu_context.h>)

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The symbols exported for use by MOL/rtlinux aren't getting CRCs and I
was about to fix that. But MOL is dead upstream, and the latest work on
it was to make it use KVM instead of its own kernel module. So remove
them instead.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Since the fault retry is now handled earlier, we can release the
mmap_sem lock earlier too and remove later unlocking previously done in
mm_fault_error().

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

In do_page_fault() if handle_mm_fault() returns VM_FAULT_RETRY, retry
the page fault handling before anything else.

This would simplify the handling of the mmap_sem lock in this part of
the code.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Move mmap_sem releasing in the do_sigbus()'s unique caller : mm_fault_error()

No functional changes.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

PNV_IODA_PE_DEV is only used for NPU devices (emulated PCI bridges
representing NVLink). These are added to IOMMU groups with corresponding
NVIDIA devices after all non-NPU PEs are setup; a special helper -
pnv_pci_ioda_setup_iommu_api() - handles this in pnv_pci_ioda_fixup().

The pnv_pci_ioda2_setup_dma_pe() helper sets up DMA for a PE. It is called
for VFs (so it does not handle NPU case) and PCI bridges but only
IODA1 and IODA2 types. An NPU bridge has its own type id (PNV_PHB_NPU)
so pnv_pci_ioda2_setup_dma_pe() cannot be called on NPU and therefore
(pe->flags & PNV_IODA_PE_DEV) is always "false".

This removes not used iommu_add_device(). This should not cause any
behavioral change.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The iommu_table_ops callbacks are declared CPU endian as they take and
return "unsigned long"; underlying hardware tables are big-endian.

However get() was missing be64_to_cpu(), this adds the missing conversion.

The only caller of this is crash dump at arch/powerpc/kernel/iommu.c,
iommu_table_clear() which only compares TCE to zero so this change
should not cause behavioral change.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Sparse emits a warning: symbol 'prepare_ftrace_return' was not
declared. Should it be static? prepare_ftrace_return() is called from
assembler and should not be static.

Add a prototype for it to asm-prototypes.h and include that in ftrace.c.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Sparse emits two symbol not declared warnings for swsusp.c. The two
functions, save_processor_state() and restore_processor_state() are
declared already in suspend.h, so include it.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

struct hcall_stats is only used in hvCall_inst.c, so move it there.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Fix an assembler error when the THREAD_SIZE is greater than 16k.

Signed-off-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Shift the logic for defining THREAD_SHIFT logic to Kconfig in order to
allow override by users.

Signed-off-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

As of commit 438cc81a ("powerpc/pseries: Automatically resize HPT
for memory hot add/remove"), when running on the pseries platform, we
always attempt to use the PAPR extension to resize the hashed page
table (HPT) when we add or remove memory.

This is fine, but when the extension is not available we'll give a
harmless, but scary warning. Instead check if the firmware supports HPT
resizing before populating the mmu_hash_ops.resize_hpt pointer.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Test runs on a ppc64 BE guest succeeded. linux/samples/statx/test-statx
program was executed on the following file types,

1. Regular file
2. Directory
3. device file
4. symlink
5. Named pipe

The test run also included invoking test-statx with the runtime options
provided in the main() function of test-statx.c

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The purgatory code defines global variables which are referenced via a
symbol lookup in the kexec code (core and arch).

A recent commit addressing sparse warnings made these static and thereby
broke kexec_file.

Why did this happen? Simply because the whole machinery is undocumented and
lacks any form of forward declarations. The variable names are unspecific
and lack a prefix, so adding forward declarations creates shadow variables
in the core code. Aside of that the code relies on magic constants and
duplicate struct definitions with no way to ensure that these things stay
in sync. The section placement of the purgatory variables happened by
chance and not by design.

Unbreak kexec and cleanup the mess:

 - Add proper forward declarations and document the usage
 - Use common struct definition
 - Use the proper common defines instead of magic constants
 - Add a purgatory_ prefix to have a proper name space
 - Use ARRAY_SIZE() instead of a homebrewn reimplementation
 - Add proper sections to the purgatory variables [ From Mike ]

Fixes: 72042a8c ("x86/purgatory: Make functions and variables static")
Reported-by: Mike Galbraith <&lt;efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Nicholas Mc Guire <der.herr@hofr.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Tobin C. Harding" <me@tobin.cc>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1703101315140.3681@nanos


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Add POWER9 machine check handler. There are several new types of errors
added, so logging messages for those are also added.

This doesn't attempt to reuse any of the P7/8 defines or functions,
because that becomes too complex. The better option in future is to use
a table driven approach.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Currently severity and initiator are always set to MCE_SEV_ERROR_SYNC and
MCE_INITIATOR_CPU in the core mce code. Allow them to be set by the
machine specific mce handlers.

No functional change for existing handlers.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

A synchronous machine check is an exception raised by the attempt to
execute the current instruction. If the error can't be corrected, it
can make sense to SIGBUS the currently running process.

In other cases, the error condition is not related to the current
instruction, so killing the current process is not the right thing to
do.

Today, all machine checks are MCE_SEV_ERROR_SYNC, so this has no
practical change. It will be used to handle POWER9 asynchronous
machine checks.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

We use pte_write() to check whethwer the pte entry is writable.  This is
mostly used to later mark the pte read only if it is writable.  The other
use of pte_write() is to check whether the pte_entry is writable so that
hardware page table entry can be marked accordingly.  This is used in kvm
where we look at qemu page table entry and update hardware hash page table
for the guest with correct write enable bit.

With the above, for the first usage we should also check the savedwrite
bit so that we can correctly clear the savedwite bit.  For the later, we
add a new variant __pte_write().

With this we can revert write_protect_page part of 595cd8f2 ("mm/ksm:
handle protnone saved writes when making page write protect").  But I left
it as it is as an example code for savedwrite check.

Fixes: c137a275 ("powerpc/mm/autonuma: switch ppc64 to its own implementation of saved write")
Link: http://lkml.kernel.org/r/1488203787-17849-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com


Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We need to mark pages of parent process read only on fork.  Numa fault
pte needs a protnone ptes variant with saved write flag set.  On fork we
need to make sure we remove the saved write bit.  Instead of adding the
protnone check in the caller update ptep_set_wrprotect variants to clear
savedwrite bit.

Without this we see random segfaults in application on fork.

Fixes: c137a275 ("powerpc/mm/autonuma: switch ppc64 to its own implementation of saved write")
Link: http://lkml.kernel.org/r/1488203787-17849-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com


Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If an architecture uses 4level-fixup.h we don't need to do anything as
it includes 5level-fixup.h.

If an architecture uses pgtable-nop*d.h, define __ARCH_USE_5LEVEL_HACK
before inclusion of the header. It makes asm-generic code to use
5level-fixup.h.

If an architecture has 4-level paging or folds levels on its own,
include 5level-fixup.h directly.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

On POWERNV platform, in order to do DMA via IOMMU (i.e. 32bit DMA in
our case), a device needs an iommu_table pointer set via
set_iommu_table_base().

The codeflow is:
- pnv_pci_ioda2_setup_dma_pe()
	- pnv_pci_ioda2_setup_default_config()
	- pnv_ioda_setup_bus_dma() [1]

pnv_pci_ioda2_setup_dma_pe() creates IOMMU groups,
pnv_pci_ioda2_setup_default_config() does default DMA setup,
pnv_ioda_setup_bus_dma() takes a bus PE (on IODA2, all physical function
PEs as bus PEs except NPU), walks through all underlying buses and
devices, adds all devices to an IOMMU group and sets iommu_table.

On IODA2, when VFIO is used, it takes ownership over a PE which means it
removes all tables and creates new ones (with a possibility of sharing
them among PEs). So when the ownership is returned from VFIO to
the kernel, the iommu_table pointer written to a device at [1] is
stale and needs an update.

This adds an "add_to_group" parameter to pnv_ioda_setup_bus_dma()
(in fact re-adds as it used to be there a while ago for different
reasons) to tell the helper if a device needs to be added to
an IOMMU group with an iommu_table update or just the latter.

This calls pnv_ioda_setup_bus_dma(..., false) from
pnv_ioda2_release_ownership() so when the ownership is restored,
32bit DMA can work again for a device. This does the same thing
on obtaining ownership as the iommu_table point is stale at this point
anyway and it is safer to have NULL there.

We did not hit this earlier as all tested devices in recent years were
only using 64bit DMA; the rare exception for this is MPT3 SAS adapter
which uses both 32bit and 64bit DMA access and it has not been tested
with VFIO much.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The IODA2 specification says that a 64 DMA address cannot use top 4 bits
(3 are reserved and one is a "TVE select"); bottom page_shift bits
cannot be used for multilevel table addressing either.

The existing IODA2 table allocation code aligns the minimum TCE table
size to PAGE_SIZE so in the case of 64K system pages and 4K IOMMU pages,
we have 64-4-12=48 bits. Since 64K page stores 8192 TCEs, i.e. needs
13 bits, the maximum number of levels is 48/13 = 3 so we physically
cannot address more and EEH happens on DMA accesses.

This adds a check that too many levels were requested.

It is still possible to have 5 levels in the case of 4K system page size.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

MMCRA[SDAR_MODE] specifices how the SDAR should be updated in
continous sampling mode. On P9 it must be set to 0b00 when
MMCRA[63] is set.

Fixes: c7c3f568 ('powerpc/perf: macros for power9 format encoding')
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Power9 DD1 do not support PMU_HAS_SIER flag and sdsync in
perf_get_data_addr() defaults to MMCRA_SDSYNC which is wrong. Since
power9 MMCRA does not support SDSYNC bit, patch includes PPMU_NO_SIAR
flag to the check and set the sdsync with MMCRA_SAMPLE_ENABLE;

Fixes: 27593d72 ("powerpc/perf: Use MSR to report privilege level on P9 DD1")
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

It is invalid to call del_gendisk() when disk->queue is NULL. Fix error
handling in axon_ram_probe() to avoid doing that.

Also del_gendisk() does not drop a reference to gendisk allocated by
alloc_disk(). That has to be done by put_disk(). Add that call where
needed.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

Turning on crypto self-tests on a POWER8 shows:

    alg: hash: Test 1 failed for crc32c-vpmsum
    00000000: ff ff ff ff

Comparing the code with the Intel CRC32c implementation on which
ours is based shows that we are doing an init with 0, not ~0
as CRC32c requires.

This probably wasn't caught because btrfs does its own weird
open-coded initialisation.

Initialise our internal context to ~0 on init.

This makes the self-tests pass, and btrfs continues to work.

Fixes: 6dd7a82c ("crypto: powerpc - Add POWER8 optimised crc32c")
Cc: Anton Blanchard <anton@samba.org>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Axtens <dja@axtens.net>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Recent toolchains force the TOC to be 256 byte aligned. We need to
enforce this alignment in the zImage linker script, otherwise pointers
to our TOC variables (__toc_start) could be incorrect. If the actual
start of the TOC and __toc_start don't have the same value we crash
early in the zImage wrapper.

Cc: stable@vger.kernel.org
Suggested-by: Alan Modra <amodra@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

We have a big list of selects under CONFIG_PPC, and currently they're
completely unsorted. This means people tend to add new selects at the
bottom of the list, and so two commits which both add a new select will
often conflict.

Instead sort it alphabetically. This is nicer in and of itself, but also
means two commits that add a new select will have a greater chance of
not conflicting.

Add a note at the top and bottom asking people to keep it sorted.

And while we're here pad out the 'if' expressions to make them stand
out.

Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>