Apart from SRESET, MCE, and syscall (hcall variant), the SRR type
interrupts are not escalated to hypervisor mode, so are delivered to
the OS.

When running PR KVM, the OS is the hypervisor, and the guest runs with
MSR[PR]=1 (ie. usermode), so these interrupts must test if a guest was
running when interrupted. These tests are required at the real-mode
entry points because the PR KVM host runs with LPCR[AIL]=0.

In HV KVM and nested HV KVM, the guest always receives these
interrupts, so there is no need for the host to make this test. So
remove the tests if PR KVM is not configured.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-21-npiggin@gmail.com

A few of the non-standard handlers are left uncommented. Some more
description could be added to some.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-20-npiggin@gmail.com

Remove more magic numbers and replace with nicely named bools.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-19-npiggin@gmail.com

The reduction in interrupt entry size allows some handlers to be
re-inlined.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-18-npiggin@gmail.com

The hdec interrupt handler is reported to sometimes fire in Linux if
KVM leaves it pending after a guest exists. This is harmless, so there
is a no-op handler for it.

The interrupt handler currently uses the regular kernel stack. Change
this to avoid touching the stack entirely.

This should be the last place where the regular Linux stack can be
accessed with asynchronous interrupts (including PMI) soft-masked.
It might be possible to take advantage of this invariant, e.g., to
context switch the kernel stack SLB entry without clearing MSR[EE].
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-17-npiggin@gmail.com

Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-16-npiggin@gmail.com

These are used infrequently enough they don't provide much help, so
inline them.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-15-npiggin@gmail.com

Replace IEARLY=1 and IEARLY=2 with IBRANCH_COMMON, which controls if
the entry code branches to a common handler; and IREALMODE_COMMON,
which controls whether the common handler should remain in real mode.

These special cases no longer avoid loading the SRR registers, there
is no point as most of them load the registers immediately anyway.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-14-npiggin@gmail.com

This allows more code to be moved out of unrelocated regions. The
system call KVMTEST is changed to be open-coded and remain in the
tramp area to avoid having to move it to entry_64.S. The custom nature
of the system call entry code means the hcall case can be made more
streamlined than regular interrupt handlers.

mpe: Incorporate fix from Nick:

Moving KVM test to the common entry code missed the case of HMI and
MCE, which do not do __GEN_COMMON_ENTRY (because they don't want to
switch to virt mode).

This means a MCE or HMI exception that is taken while KVM is running a
guest context will not be switched out of that context, and KVM won't
be notified. Found by running sigfuz in guest with patched host on
POWER9 DD2.3, which causes some TM related HMI interrupts (which are
expected and supposed to be handled by KVM).

This fix adds a __GEN_REALMODE_COMMON_ENTRY for those handlers to add
the KVM test. This makes them look a little more like other handlers
that all use __GEN_COMMON_ENTRY.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-13-npiggin@gmail.com

As well as moving code out of the unrelocated vectors, this allows the
masked handlers to be moved to common code, and allows the soft_nmi
handler to be generated more like a regular handler.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-12-npiggin@gmail.com

The real mode interrupt entry points currently use rfid to branch to
the common handler in virtual mode. This is a significant amount of
code, and forces other code (notably the KVM test) to live in the
real mode handler.

In the interest of minimising the amount of code that runs unrelocated
move the switch to virt mode into the common code, and do it with
mtmsrd, which avoids clobbering SRRs (although the post-KVMTEST
performance of real-mode interrupt handlers is not a big concern these
days).

This requires CTR to always be saved (real-mode needs to reach 0xc...)
but that's not a huge impact these days. It could be optimized away in
future.

mpe: Incorporate fix from Nick:

It's possible for interrupts to be replayed when TM is enabled and
suspended, for example rt_sigreturn, where the mtmsrd MSR_KERNEL in
the real-mode entry point to the common handler causes a TM Bad Thing
exception (due to attempting to clear suspended).

The fix for this is to have replay interrupts go to the _virt entry
point and skip the mtmsrd, which matches what happens before this
patch.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-11-npiggin@gmail.com

Rather than using DAR=2 to select the i-side registers, add an
explicit option.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-10-npiggin@gmail.com

Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-9-npiggin@gmail.com

Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-8-npiggin@gmail.com

Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-7-npiggin@gmail.com

Aside from label names and BUG line numbers, the generated code change
is an additional HMI KVM handler added for the "late" KVM handler,
because early and late HMI generation is achieved by defining two
different interrupt types.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-6-npiggin@gmail.com

These don't provide a large amount of code sharing. Removing them
makes code easier to shuffle around. For example, some of the common
instructions will be moved into the common code gen macro.

No generated code change.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-5-npiggin@gmail.com

No generated code change.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-4-npiggin@gmail.com

No generated code change.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-3-npiggin@gmail.com

The code generation macro arguments are difficult to read, and
defaults can't easily be used.

This introduces a block where parameters can be set for interrupt
handler code generation by the subsequent macros, and adds the first
generation macro for interrupt entry.

One interrupt handler is converted to the new macros to demonstrate
the change, the rest will be coverted all at once.

No generated code change.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-2-npiggin@gmail.com

Before:

  WARNING: CPU: 0 PID: 494 at arch/powerpc/kernel/irq.c:343
  CPU: 0 PID: 494 Comm: a Tainted: G        W
  NIP:  c00000000001ed2c LR: c000000000d13190 CTR: c00000000003f910
  REGS: c0000001fffd3870 TRAP: 0700   Tainted: G        W
  MSR:  8000000000021003 <SF,ME,RI,LE>  CR: 28000488  XER: 00000000
  CFAR: c00000000001ec90 IRQMASK: 0
  GPR00: c000000000aeb12c c0000001fffd3b00 c0000000012ba300 0000000000000000
  GPR04: 0000000000000000 0000000000000000 000000010bd207c8 6b00696e74657272
  GPR08: 0000000000000000 0000000000000000 0000000000000000 efbeadde00000000
  GPR12: 0000000000000000 c0000000014a0000 0000000000000000 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR24: 0000000000000000 0000000000000000 0000000000000000 000000010bd207bc
  GPR28: 0000000000000000 c00000000148a898 0000000000000000 c0000001ffff3f50
  NIP [c00000000001ed2c] arch_local_irq_restore.part.0+0xac/0x100
  LR [c000000000d13190] _raw_spin_unlock_irqrestore+0x50/0xc0
  Call Trace:
  Instruction dump:
  60000000 7d2000a6 71298000 41820068 39200002 7d210164 4bffff9c 60000000
  60000000 7d2000a6 71298000 4c820020 <0fe00000> 4e800020 60000000 60000000

After:

  WARNING: CPU: 0 PID: 499 at arch/powerpc/kernel/irq.c:343
  CPU: 0 PID: 499 Comm: a Not tainted
  NIP:  c00000000001ed2c LR: c000000000d13210 CTR: c00000000003f980
  REGS: c0000001fffd3870 TRAP: 0700   Not tainted
  MSR:  8000000000021003 <SF,ME,RI,LE>  CR: 28000488  XER: 00000000
  CFAR: c00000000001ec90 IRQMASK: 0
  GPR00: c000000000aeb1ac c0000001fffd3b00 c0000000012ba300 0000000000000000
  GPR04: 0000000000000000 0000000000000000 00000001347607c8 6b00696e74657272
  GPR08: 0000000000000000 0000000000000000 0000000000000000 efbeadde00000000
  GPR12: 0000000000000000 c0000000014a0000 0000000000000000 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR24: 0000000000000000 0000000000000000 0000000000000000 00000001347607bc
  GPR28: 0000000000000000 c00000000148a898 0000000000000000 c0000001ffff3f50
  NIP [c00000000001ed2c] arch_local_irq_restore.part.0+0xac/0x100
  LR [c000000000d13210] _raw_spin_unlock_irqrestore+0x50/0xc0
  Call Trace:
  [c0000001fffd3b20] [c000000000aeb1ac] of_find_property+0x6c/0x90
  [c0000001fffd3b70] [c000000000aeb1f0] of_get_property+0x20/0x40
  [c0000001fffd3b90] [c000000000042cdc] rtas_token+0x3c/0x70
  [c0000001fffd3bb0] [c0000000000dc318] fwnmi_release_errinfo+0x28/0x70
  [c0000001fffd3c10] [c0000000000dcd8c] pseries_machine_check_realmode+0x1dc/0x540
  [c0000001fffd3cd0] [c00000000003fe04] machine_check_early+0x54/0x70
  [c0000001fffd3d00] [c000000000008384] machine_check_early_common+0x134/0x1f0
  --- interrupt: 200 at 0x1347607c8
      LR = 0x7fffafbd8328
  Instruction dump:
  60000000 7d2000a6 71298000 41820068 39200002 7d210164 4bffff9c 60000000
  60000000 7d2000a6 71298000 4c820020 <0fe00000> 4e800020 60000000 60000000
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200325104144.158362-1-npiggin@gmail.com

In restore_tm_sigcontexts() we take the trap value directly from the
user sigcontext with no checking:

	err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);

This means we can be in the kernel with an arbitrary regs->trap value.

Although that's not immediately problematic, there is a risk we could
trigger one of the uses of CHECK_FULL_REGS():

	#define CHECK_FULL_REGS(regs)	BUG_ON(regs->trap & 1)

It can also cause us to unnecessarily save non-volatile GPRs again in
save_nvgprs(), which shouldn't be problematic but is still wrong.

It's also possible it could trick the syscall restart machinery, which
relies on regs->trap not being == 0xc00 (see 9a81c16b ("powerpc:
fix double syscall restarts")), though I haven't been able to make
that happen.

Finally it doesn't match the behaviour of the non-TM case, in
restore_sigcontext() which zeroes regs->trap.

So change restore_tm_sigcontexts() to zero regs->trap.

This was discovered while testing Nick's upcoming rewrite of the
syscall entry path. In that series the call to save_nvgprs() prior to
signal handling (do_notify_resume()) is removed, which leaves the
low-bit of regs->trap uncleared which can then trigger the FULL_REGS()
WARNs in setup_tm_sigcontexts().

Fixes: 2b0a576d ("powerpc: Add new transactional memory state to the signal context")
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200401023836.3286664-1-mpe@ellerman.id.au

As per ISA an isync is only needed on instruction cache block
invalidate. Remove the same from dcache invalidate.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320103242.229223-1-aneesh.kumar@linux.ibm.com

.globl sets the symbol binding to STB_GLOBAL while .weak sets the
binding to STB_WEAK. GNU as let .weak override .globl since
binutils-gdb 5ca547dc2399a0a5d9f20626d4bf5547c3ccfddd (1996). Clang
integrated assembler let the last win but it may error in the future.

Since it is a convention that only one binding directive is used, just
delete .globl.

Fixes: ee9d21b3 ("powerpc/boot: Ensure _zimage_start is a weak symbol")
Signed-off-by: NFangrui Song <maskray@google.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200325164257.170229-1-maskray@google.com

memcpy_mcsafe has been implemented for power machines which is used
by pmem infrastructure, so that an UE encountered during memcpy from
pmem devices would not result in panic instead a right error code
is returned. The implementation expects machine check handler to ignore
the event and set nip to continue the execution from fixup code.

Appropriate changes are already made to powernv machine check handler,
make similar changes to pseries machine check handler to ignore the
the event and set nip to continue execution at the fixup entry if we
hit UE at an instruction with a fixup entry.

while we are at it, have a common function which searches the exception
table entry and updates nip with fixup address, and any future common
changes can be made in this function that are valid for both architectures.

powernv changes are made by
commit 895e3dce ("powerpc/mce: Handle UE event for memcpy_mcsafe")
Reviewed-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: NSantosh S <santosh@fossix.org>
Signed-off-by: NGanesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200326184916.31172-1-ganeshgr@linux.ibm.com

We can avoid the #ifdef by using IS_ENABLED() in the existing
condition check.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200313112020.28235-2-mpe@ellerman.id.au

We don't need the NULL check of np, the result is the same because the
OF helpers cope with NULL, of_node_to_nid(NULL) == NUMA_NO_NODE (-1).
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200313112020.28235-1-mpe@ellerman.id.au

It's over 10 years since the last commit from Vitaly, so I suspect
he's moved on to other things.

Christophe has been the primary contributor to 8xx in the last several
years, so anoint him as the maintainer.

Remove the dead penguingppc.org link.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Link: https://lore.kernel.org/r/20200225092534.9587-1-mpe@ellerman.id.au

Scott said he was still maintaining this "sort of", so change the
status to Odd Fixes.

Kumar has long ago moved on to greener pastures.

Remove the dead penguinppc.org link.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NScott Wood <oss@buserror.net>
Link: https://lore.kernel.org/r/20200224233146.23734-8-mpe@ellerman.id.au

Ben is no longer actively maintaining the powermac code, but we know
where to find him if something really needs attention.

The www.penguinppc.org link is dead so remove it.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200224233146.23734-7-mpe@ellerman.id.au

It's several years since the last commit from Anatolij, so mark
MPC5XXX as "Odd Fixes" rather than "Maintained".

Also the git link no longer works so remove it.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NAnatolij Gustschin <agust@denx.de>
Link: https://lore.kernel.org/r/20200224233146.23734-6-mpe@ellerman.id.au

This has been orphaned for ~7 years, remove it.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NGrant Likely <grant.likely@arm.com>
Link: https://lore.kernel.org/r/20200224233146.23734-5-mpe@ellerman.id.au

The 4xx platforms are no longer maintained.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NAlistair Popple <alistair@popple.id.au>
Link: https://lore.kernel.org/r/20200224233146.23734-4-mpe@ellerman.id.au

The PA SEMI entries have been orphaned for 3 ½ years, so fold them
into the main POWERPC entry. The result of get_maintainer.pl is more
or less unchanged.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NOlof Johansson <olof@lixom.net>
Link: https://lore.kernel.org/r/20200224233146.23734-3-mpe@ellerman.id.au

The wiki has moved, update the link.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200224233146.23734-2-mpe@ellerman.id.au

A while back Paul pointed out I'd been maintaining the tree more or
less solo for over five years, so perhaps it's time to update the
MAINTAINERS entry.

Ben & Paul still wrote most of the code, so keep them as Reviewers so
they still get Cc'ed on things. But if you're wondering why your patch
hasn't been merged that's my fault.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200224233146.23734-1-mpe@ellerman.id.au

The reason debuggers add an ASCII dump to other types of memory dumps
is to give the user visual reference points in the case that ASCII
strings are adjacent to other structures or element.  For example,
when examining the task_struct structure one can look for the comm[]
string and use it to locate other important elements.

ASCII strings do not have endianess, they exist in memory in the same
order regardless of CPU endianess. ASCII strings are, by definition,
human readable and so should be presented in a human readable format.

For these reasons, the supplemental ASCII dump does not re-order
the strings from memory to match the endianess of the corresponding
16, 32, or 64 bit words. That would make the ASCII dump much less
useful.
Signed-off-by: NDouglas Miller <dougmill@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1488205694-13337-1-git-send-email-dougmill@linux.vnet.ibm.com

As does XMON, the debugfs file /sys/kernel/debug/powerpc/xive exposes
the XIVE internal state of the machine CPUs and interrupts. Available
on the PowerNV and sPAPR platforms.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
[mpe: Make the debugfs file 0400]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306150143.5551-5-clg@kaod.org

Some firmwares or hypervisors can advertise different source
characteristics. Track their value under XMON. What we are mostly
interested in is the StoreEOI flag.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306150143.5551-4-clg@kaod.org

The PowerNV platform has multiple IRQ chips and the xmon command
dumping the state of the XIVE interrupt should only operate on the
XIVE IRQ chip.

Fixes: 5896163f ("powerpc/xmon: Improve output of XIVE interrupts")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306150143.5551-3-clg@kaod.org