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6 years agopowerpc/prom_init: Replace __initdata with __prombss when applicable
Benjamin Herrenschmidt [Mon, 15 Oct 2018 02:49:52 +0000 (13:49 +1100)]
powerpc/prom_init: Replace __initdata with __prombss when applicable

This replaces all occurrences of __initdata for uninitialized
data with a new __prombss

Currently __promdata is defined to be __initdata but we'll
eventually change that.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/pseries: Add driver for PAPR SCM regions
Oliver O'Halloran [Sun, 14 Oct 2018 23:18:28 +0000 (10:18 +1100)]
powerpc/pseries: Add driver for PAPR SCM regions

Adds a driver that implements support for enabling and accessing PAPR
SCM regions. Unfortunately due to how the PAPR interface works we can't
use the existing of_pmem driver (yet) because:

 a) The guest is required to use the H_SCM_BIND_MEM h-call to add
    add the SCM region to it's physical address space, and
 b) There is currently no mechanism for relating a bare of_pmem region
    to the backing DIMM (or not-a-DIMM for our case).

Both of these are easily handled by rolling the functionality into a
seperate driver so here we are...

Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/pseries: PAPR persistent memory support
Oliver O'Halloran [Sun, 14 Oct 2018 23:18:27 +0000 (10:18 +1100)]
powerpc/pseries: PAPR persistent memory support

This patch implements support for discovering storage class memory
devices at boot and for handling hotplug of new regions via RTAS
hotplug events.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Fix CONFIG_MEMORY_HOTPLUG=n build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/traps: fix machine check handlers to use pr_cont()
Christophe Leroy [Mon, 15 Oct 2018 07:20:45 +0000 (07:20 +0000)]
powerpc/traps: fix machine check handlers to use pr_cont()

When printing the machine check cause, the cause appears on the
following line due to bad use of printk without \n:

[   33.663993] Machine check in kernel mode.
[   33.664011] Caused by (from SRR1=9032):
[   33.664036] Data access error at address c90c8000

This patch fixes it by using pr_cont() for the second part:

[  133.258131] Machine check in kernel mode.
[  133.258146] Caused by (from SRR1=9032): Data access error at address c90c8000

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/book3e: redefine pte_mkprivileged() and pte_mkuser()
Christophe Leroy [Wed, 17 Oct 2018 13:03:22 +0000 (13:03 +0000)]
powerpc/book3e: redefine pte_mkprivileged() and pte_mkuser()

Book3e defines both _PAGE_USER and _PAGE_PRIVILEGED, so the nohash
default pte_mkprivileged() and pte_mkuser() are not usable.

This patch redefines them for book3e.

In theorie, only pte_mkprivileged() needs to be redefined because
_PAGE_USER includes _PAGE_PRIVILEGED, but it is less confusing
to redefine both.

Fixes: a0da4bc166f2 ("powerpc/mm: Allow platforms to redefine some helpers")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: Make pte_pgprot return all pte bits
Aneesh Kumar K.V [Wed, 17 Oct 2018 09:39:21 +0000 (15:09 +0530)]
powerpc/mm: Make pte_pgprot return all pte bits

Other archs do the same and instead of adding required pte bits (which
got masked out) in __ioremap_at(), make sure we filter only pfn bits
out.

Fixes: 26973fa5ac0e ("powerpc/mm: use pte helpers in generic code")
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: Increase the max addressable memory to 2PB
Aneesh Kumar K.V [Thu, 20 Sep 2018 08:33:58 +0000 (14:03 +0530)]
powerpc/mm: Increase the max addressable memory to 2PB

Currently we limit the max addressable memory to 128TB. This patch increase the
limit to 2PB. We can have devices like nvdimm which adds memory above 512TB
limit.

We still don't support regular system ram above 512TB. One of the challenge with
that is the percpu allocator, that allocates per node memory and use the max
distance between them as the percpu offsets. This means with large gap in
address space ( system ram above 1PB) we will run out of vmalloc space to map
the percpu allocation.

In order to support addressable memory above 512TB, kernel should be able to
linear map this range. To do that with hash translation we now add 4 context
to kernel linear map region. Our per context addressable range is 512TB. We
still keep VMALLOC and VMEMMAP region to old size. SLB miss handlers is updated
to validate these limit.

We also limit this update to SPARSEMEM_VMEMMAP and SPARSEMEM_EXTREME

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm/hash: Rename get_ea_context to get_user_context
Aneesh Kumar K.V [Thu, 20 Sep 2018 08:33:57 +0000 (14:03 +0530)]
powerpc/mm/hash: Rename get_ea_context to get_user_context

We will be adding get_kernel_context later. Update function name to indicate
this handle context allocation user space address.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/64s/hash: Add some SLB debugging tests
Nicholas Piggin [Tue, 2 Oct 2018 14:27:59 +0000 (00:27 +1000)]
powerpc/64s/hash: Add some SLB debugging tests

This adds CONFIG_DEBUG_VM checks to ensure:
  - The kernel stack is in the SLB after it's flushed and bolted.
  - We don't insert an SLB for an address that is aleady in the SLB.
  - The kernel SLB miss handler does not take an SLB miss.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/64s/hash: Simplify slb_flush_and_rebolt()
Nicholas Piggin [Tue, 2 Oct 2018 14:27:58 +0000 (00:27 +1000)]
powerpc/64s/hash: Simplify slb_flush_and_rebolt()

slb_flush_and_rebolt() is misleading, it is called in virtual mode, so
it can not possibly change the stack, so it should not be touching the
shadow area. And since vmalloc is no longer bolted, it should not
change any bolted mappings at all.

Change the name to slb_flush_and_restore_bolted(), and have it just
load the kernel stack from what's currently in the shadow SLB area.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/64s/hash: Add a SLB preload cache
Nicholas Piggin [Fri, 14 Sep 2018 15:30:56 +0000 (01:30 +1000)]
powerpc/64s/hash: Add a SLB preload cache

When switching processes, currently all user SLBEs are cleared, and a
few (exec_base, pc, and stack) are preloaded. In trivial testing with
small apps, this tends to miss the heap and low 256MB segments, and it
will also miss commonly accessed segments on large memory workloads.

Add a simple round-robin preload cache that just inserts the last SLB
miss into the head of the cache and preloads those at context switch
time. Every 256 context switches, the oldest entry is removed from the
cache to shrink the cache and require fewer slbmte if they are unused.

Much more could go into this, including into the SLB entry reclaim
side to track some LRU information etc, which would require a study of
large memory workloads. But this is a simple thing we can do now that
is an obvious win for common workloads.

With the full series, process switching speed on the context_switch
benchmark on POWER9/hash (with kernel speculation security masures
disabled) increases from 140K/s to 178K/s (27%).

POWER8 does not change much (within 1%), it's unclear why it does not
see a big gain like POWER9.

Booting to busybox init with 256MB segments has SLB misses go down
from 945 to 69, and with 1T segments 900 to 21. These could almost all
be eliminated by preloading a bit more carefully with ELF binary
loading.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/64s/hash: Provide arch_setup_exec() hooks for hash slice setup
Nicholas Piggin [Fri, 14 Sep 2018 15:30:55 +0000 (01:30 +1000)]
powerpc/64s/hash: Provide arch_setup_exec() hooks for hash slice setup

This will be used by the SLB code in the next patch, but for now this
sets the slb_addr_limit to the correct size for 32-bit tasks.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/64s/hash: Add SLB allocation status bitmaps
Nicholas Piggin [Fri, 14 Sep 2018 15:30:53 +0000 (01:30 +1000)]
powerpc/64s/hash: Add SLB allocation status bitmaps

Add 32-entry bitmaps to track the allocation status of the first 32
SLB entries, and whether they are user or kernel entries. These are
used to allocate free SLB entries first, before resorting to the round
robin allocator.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/64s/hash: Convert SLB miss handlers to C
Nicholas Piggin [Fri, 14 Sep 2018 15:30:51 +0000 (01:30 +1000)]
powerpc/64s/hash: Convert SLB miss handlers to C

This patch moves SLB miss handlers completely to C, using the standard
exception handler macros to set up the stack and branch to C.

This can be done because the segment containing the kernel stack is
always bolted, so accessing it with relocation on will not cause an
SLB exception.

Arbitrary kernel memory must not be accessed when handling kernel
space SLB misses, so care should be taken there. However user SLB
misses can access any kernel memory, which can be used to move some
fields out of the paca (in later patches).

User SLB misses could quite easily reconcile IRQs and set up a first
class kernel environment and exit via ret_from_except, however that
doesn't seem to be necessary at the moment, so we only do that if a
bad fault is encountered.

[ Credit to Aneesh for bug fixes, error checks, and improvements to
  bad address handling, etc ]

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Disallow tracing for all of slb.c for now.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/64: Interrupts save PPR on stack rather than thread_struct
Nicholas Piggin [Fri, 12 Oct 2018 13:15:16 +0000 (00:15 +1100)]
powerpc/64: Interrupts save PPR on stack rather than thread_struct

PPR is the odd register out when it comes to interrupt handling, it is
saved in current->thread.ppr while all others are saved on the stack.

The difficulty with this is that accessing thread.ppr can cause a SLB
fault, but the SLB fault handler implementation in C change had
assumed the normal exception entry handlers would not cause an SLB
fault.

Fix this by allocating room in the interrupt stack to save PPR.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/ptrace: Don't use sizeof(struct pt_regs) in ptrace code
Michael Ellerman [Fri, 12 Oct 2018 13:39:31 +0000 (00:39 +1100)]
powerpc/ptrace: Don't use sizeof(struct pt_regs) in ptrace code

Now that we've split the user & kernel versions of pt_regs we need to
be more careful in the ptrace code.

For now we've ensured the location of the fields in both structs is
the same, so most of the ptrace code doesn't need updating.

But there are a few places where we use sizeof(pt_regs), and these
will be wrong as soon as we increase the size of the kernel structure.

So flip them all to use sizeof(user_pt_regs).

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc: Split user/kernel definitions of struct pt_regs
Michael Ellerman [Fri, 12 Oct 2018 12:13:17 +0000 (23:13 +1100)]
powerpc: Split user/kernel definitions of struct pt_regs

We use a shared definition for struct pt_regs in uapi/asm/ptrace.h.
That means the layout of the structure is ABI, ie. we can't change it.

That would be fine if it was only used to describe the user-visible
register state of a process, but it's also the struct we use in the
kernel to describe the registers saved in an interrupt frame.

We'd like more flexibility in the content (and possibly layout) of the
kernel version of the struct, but currently that's not possible.

So split the definition into a user-visible definition which remains
unchanged, and a kernel internal one.

At the moment they're still identical, and we check that at build
time. That's because we have code (in ptrace etc.) that assumes that
they are the same. We will fix that code in future patches, and then
we can break the strict symmetry between the two structs.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/prom_init: Make "default_colors" const
Benjamin Herrenschmidt [Thu, 31 May 2018 04:33:41 +0000 (14:33 +1000)]
powerpc/prom_init: Make "default_colors" const

It's never modified.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/prom_init: Make "fake_elf" const
Benjamin Herrenschmidt [Thu, 31 May 2018 04:33:40 +0000 (14:33 +1000)]
powerpc/prom_init: Make "fake_elf" const

It is never modified

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/prom_init: Make of_workarounds static
Benjamin Herrenschmidt [Thu, 31 May 2018 04:33:39 +0000 (14:33 +1000)]
powerpc/prom_init: Make of_workarounds static

It's not used anywhere else.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/book3s64: Avoid multiple endian conversion in pte helpers
Christophe Leroy [Tue, 9 Oct 2018 13:52:20 +0000 (13:52 +0000)]
powerpc/book3s64: Avoid multiple endian conversion in pte helpers

In the same spirit as already done in pte query helpers,
this patch changes pte setting helpers to perform endian
conversions on the constants rather than on the pte value.

In the meantime, it changes pte_access_permitted() to use
pte helpers for the same reason.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/8xx: change name of a few page flags to avoid confusion
Christophe Leroy [Tue, 9 Oct 2018 13:52:18 +0000 (13:52 +0000)]
powerpc/8xx: change name of a few page flags to avoid confusion

_PAGE_PRIVILEGED corresponds to the SH bit which doesn't protect
against user access but only disables ASID verification on kernel
accesses. User access is controlled with _PMD_USER flag.

Name it _PAGE_SH instead of _PAGE_PRIVILEGED

_PAGE_HUGE corresponds to the SPS bit which doesn't really tells
that's it is a huge page but only that it is not a 4k page.

Name it _PAGE_SPS instead of _PAGE_HUGE

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: Get rid of pte-common.h
Christophe Leroy [Tue, 9 Oct 2018 13:52:16 +0000 (13:52 +0000)]
powerpc/mm: Get rid of pte-common.h

Do not include pte-common.h in nohash/32/pgtable.h

As that was the last includer, get rid of pte-common.h

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: Define platform default caches related flags
Christophe Leroy [Tue, 9 Oct 2018 13:52:14 +0000 (13:52 +0000)]
powerpc/mm: Define platform default caches related flags

Cache related flags like _PAGE_COHERENT and _PAGE_WRITETHRU
are defined on most platforms. The platforms not defining
them don't define any alternative. So we can give them a NUL
value directly for those platforms directly.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: Allow platforms to redefine some helpers
Christophe Leroy [Tue, 9 Oct 2018 13:52:12 +0000 (13:52 +0000)]
powerpc/mm: Allow platforms to redefine some helpers

The 40xx defines _PAGE_HWWRITE while others don't.
The 8xx defines _PAGE_RO instead of _PAGE_RW.
The 8xx defines _PAGE_PRIVILEGED instead of _PAGE_USER.
The 8xx defines _PAGE_HUGE and _PAGE_NA while others don't.

Lets those platforms redefine pte_write(), pte_wrprotect() and
pte_mkwrite() and get _PAGE_RO and _PAGE_HWWRITE off the common
helpers.

Lets the 8xx redefine pte_user(), pte_mkprivileged() and pte_mkuser()
and get rid of _PAGE_PRIVILEGED and _PAGE_USER default values.

Lets the 8xx redefine pte_mkhuge() and get rid of
_PAGE_HUGE default value.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/nohash/64: do not include pte-common.h
Christophe Leroy [Tue, 9 Oct 2018 13:52:10 +0000 (13:52 +0000)]
powerpc/nohash/64: do not include pte-common.h

nohash/64 only uses book3e PTE flags, so it doesn't need pte-common.h

This also allows to drop PAGE_SAO and H_PAGE_4K_PFN from pte_common.h
as they are only used by PPC64

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: Distribute platform specific PAGE and PMD flags and definitions
Christophe Leroy [Tue, 9 Oct 2018 13:52:08 +0000 (13:52 +0000)]
powerpc/mm: Distribute platform specific PAGE and PMD flags and definitions

The base kernel PAGE_XXXX definition sets are more or less platform
specific. Lets distribute them close to platform _PAGE_XXX flags
definition, and customise them to their exact platform flags.

Also defines _PAGE_PSIZE and _PTE_NONE_MASK for each platform
allthough they are defined as 0.

Do the same with _PMD flags like _PMD_USER and _PMD_PRESENT_MASK

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: Move pte_user() into nohash/pgtable.h
Christophe Leroy [Tue, 9 Oct 2018 13:52:06 +0000 (13:52 +0000)]
powerpc/mm: Move pte_user() into nohash/pgtable.h

Now the pte-common.h is only for nohash platforms, lets
move pte_user() helper out of pte-common.h to put it
together with other helpers.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/book3s/32: do not include pte-common.h
Christophe Leroy [Tue, 9 Oct 2018 13:52:04 +0000 (13:52 +0000)]
powerpc/book3s/32: do not include pte-common.h

As done for book3s/64, add necessary flags/defines in
book3s/32/pgtable.h and do not include pte-common.h

It allows in the meantime to remove all related hash
definitions from pte-common.h and to also remove
_PAGE_EXEC default as _PAGE_EXEC is defined on all
platforms except book3s/32.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: move __P and __S tables in the common pgtable.h
Christophe Leroy [Tue, 9 Oct 2018 13:52:02 +0000 (13:52 +0000)]
powerpc/mm: move __P and __S tables in the common pgtable.h

__P and __S flags are the same for all platform and should remain
as is in the future, so avoid duplication.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: drop unused page flags
Christophe Leroy [Tue, 9 Oct 2018 13:52:00 +0000 (13:52 +0000)]
powerpc/mm: drop unused page flags

The following page flags in pte-common.h can be dropped:

_PAGE_ENDIAN is only used in mm/fsl_booke_mmu.c and is defined in
asm/nohash/32/pte-fsl-booke.h

_PAGE_4K_PFN is nowhere defined nor used

_PAGE_READ, _PAGE_WRITE and _PAGE_PTE are only defined and used
in book3s/64

The following page flags in book3s/64/pgtable.h can be dropped as
they are not used on this platform nor by common code.

_PAGE_NA, _PAGE_RO, _PAGE_USER and _PAGE_PSIZE

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: Split dump_pagelinuxtables flag_array table
Christophe Leroy [Tue, 9 Oct 2018 13:51:58 +0000 (13:51 +0000)]
powerpc/mm: Split dump_pagelinuxtables flag_array table

To reduce the complexity of flag_array, and allow the removal of
default 0 value of non existing flags, lets have one flag_array
table for each platform family with only the really existing flags.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: use pte helpers in generic code
Christophe Leroy [Tue, 9 Oct 2018 13:51:56 +0000 (13:51 +0000)]
powerpc/mm: use pte helpers in generic code

Get rid of platform specific _PAGE_XXXX in powerpc common code and
use helpers instead.

mm/dump_linuxpagetables.c will be handled separately

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: don't use _PAGE_EXEC for calling hash_preload()
Christophe Leroy [Tue, 9 Oct 2018 13:51:54 +0000 (13:51 +0000)]
powerpc/mm: don't use _PAGE_EXEC for calling hash_preload()

The 'access' parameter of hash_preload() is either 0 or _PAGE_EXEC.
Among the two versions of hash_preload(), only the PPC64 one is
doing something with this 'access' parameter.

In order to remove the use of _PAGE_EXEC outside platform code,
'access' parameter is replaced by 'is_exec' which will be either
true of false, and the PPC64 version of hash_preload() creates
the access flag based on 'is_exec'.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: add pte helpers to query and change pte flags
Christophe Leroy [Tue, 9 Oct 2018 13:51:52 +0000 (13:51 +0000)]
powerpc/mm: add pte helpers to query and change pte flags

In order to avoid using generic _PAGE_XXX flags in powerpc
core functions, define helpers for all needed flags:
- pte_mkuser() and pte_mkprivileged() to set/unset and/or
unset/set _PAGE_USER and/or _PAGE_PRIVILEGED
- pte_hashpte() to check if _PAGE_HASHPTE is set.
- pte_ci() check if cache is inhibited (already existing on book3s/64)
- pte_exprotect() to protect against execution
- pte_exec() and pte_mkexec() to query and set page execution
- pte_mkpte() to set _PAGE_PTE flag.
- pte_hw_valid() to check _PAGE_PRESENT since pte_present does
something different on book3s/64.

On book3s/32 there is no exec protection, so pte_mkexec() and
pte_exprotect() are nops and pte_exec() returns always true.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: move some nohash pte helpers in nohash/[32:64]/pgtable.h
Christophe Leroy [Tue, 9 Oct 2018 13:51:50 +0000 (13:51 +0000)]
powerpc/mm: move some nohash pte helpers in nohash/[32:64]/pgtable.h

In order to allow their use in nohash/32/pgtable.h, we have to move the
following helpers in nohash/[32:64]/pgtable.h:
- pte_mkwrite()
- pte_mkdirty()
- pte_mkyoung()
- pte_wrprotect()

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: don't use _PAGE_EXEC in book3s/32
Christophe Leroy [Tue, 9 Oct 2018 13:51:47 +0000 (13:51 +0000)]
powerpc/mm: don't use _PAGE_EXEC in book3s/32

book3s/32 doesn't define _PAGE_EXEC, so no need to use it.

All other platforms define _PAGE_EXEC so no need to check
it is not NUL when not book3s/32.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc: handover page flags with a pgprot_t parameter
Christophe Leroy [Tue, 9 Oct 2018 13:51:45 +0000 (13:51 +0000)]
powerpc: handover page flags with a pgprot_t parameter

In order to avoid multiple conversions, handover directly a
pgprot_t to map_kernel_page() as already done for radix.

Do the same for __ioremap_caller() and __ioremap_at().

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/mm: properly set PAGE_KERNEL flags in ioremap()
Christophe Leroy [Tue, 9 Oct 2018 13:51:43 +0000 (13:51 +0000)]
powerpc/mm: properly set PAGE_KERNEL flags in ioremap()

Set PAGE_KERNEL directly in the caller and do not rely on a
hack adding PAGE_KERNEL flags when _PAGE_PRESENT is not set.

As already done for PPC64, use pgprot_cache() helpers instead of
_PAGE_XXX flags in PPC32 ioremap() derived functions.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc: don't use ioremap_prot() nor __ioremap() unless really needed.
Christophe Leroy [Tue, 9 Oct 2018 13:51:41 +0000 (13:51 +0000)]
powerpc: don't use ioremap_prot() nor __ioremap() unless really needed.

In many places, ioremap_prot() and __ioremap() can be replaced with
higher level functions like ioremap(), ioremap_coherent(),
ioremap_cache(), ioremap_wc() ...

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agosoc/fsl/qbman: use ioremap_cache() instead of ioremap_prot(0)
Christophe Leroy [Tue, 9 Oct 2018 13:51:39 +0000 (13:51 +0000)]
soc/fsl/qbman: use ioremap_cache() instead of ioremap_prot(0)

ioremap_prot() with flag set to 0 relies on a hack in
__ioremap_caller() which adds PAGE_KERNEL flags when the
handed flags don't look like a valid set of flags
(ie don't include _PAGE_PRESENT)

The intention being to map cached memory, use ioremap_cache() instead.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agodrivers/block/z2ram: use ioremap_wt() instead of __ioremap(_PAGE_WRITETHRU)
Christophe Leroy [Tue, 9 Oct 2018 13:51:37 +0000 (13:51 +0000)]
drivers/block/z2ram: use ioremap_wt() instead of __ioremap(_PAGE_WRITETHRU)

_PAGE_WRITETHRU is a target specific flag. Prefer generic functions.

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agodrivers/video/fbdev: use ioremap_wc/wt() instead of __ioremap()
Christophe Leroy [Tue, 9 Oct 2018 13:51:35 +0000 (13:51 +0000)]
drivers/video/fbdev: use ioremap_wc/wt() instead of __ioremap()

_PAGE_NO_CACHE is a platform specific flag. In addition, this flag
is misleading because one would think it requests a noncached page
whereas a noncached page is _PAGE_NO_CACHE | _PAGE_GUARDED

_PAGE_NO_CACHE alone means write combined noncached page, so lets
use ioremap_wc() instead.

_PAGE_WRITETHRU is also platform specific flag. Use ioremap_wt()
instead.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/32: Add ioremap_wt() and ioremap_coherent()
Christophe Leroy [Tue, 9 Oct 2018 13:51:33 +0000 (13:51 +0000)]
powerpc/32: Add ioremap_wt() and ioremap_coherent()

Other arches have ioremap_wt() to map IO areas write-through.
Implement it on PPC as well in order to avoid drivers using
__ioremap(_PAGE_WRITETHRU)

Also implement ioremap_coherent() to avoid drivers using
__ioremap(_PAGE_COHERENT)

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/rtas: Fix a potential race between CPU-Offline & Migration
Gautham R. Shenoy [Mon, 1 Oct 2018 10:40:39 +0000 (16:10 +0530)]
powerpc/rtas: Fix a potential race between CPU-Offline & Migration

Live Partition Migrations require all the present CPUs to execute the
H_JOIN call, and hence rtas_ibm_suspend_me() onlines any offline CPUs
before initiating the migration for this purpose.

The commit 85a88cabad57
("powerpc/pseries: Disable CPU hotplug across migrations")
disables any CPU-hotplug operations once all the offline CPUs are
brought online to prevent any further state change. Once the
CPU-Hotplug operation is disabled, the code assumes that all the CPUs
are online.

However, there is a minor window in rtas_ibm_suspend_me() between
onlining the offline CPUs and disabling CPU-Hotplug when a concurrent
CPU-offline operations initiated by the userspace can succeed thereby
nullifying the the aformentioned assumption. In this unlikely case
these offlined CPUs will not call H_JOIN, resulting in a system hang.

Fix this by verifying that all the present CPUs are actually online
after CPU-Hotplug has been disabled, failing which we restore the
state of the offline CPUs in rtas_ibm_suspend_me() and return an
-EBUSY.

Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/cacheinfo: Report the correct shared_cpu_map on big-cores
Gautham R. Shenoy [Thu, 11 Oct 2018 05:33:03 +0000 (11:03 +0530)]
powerpc/cacheinfo: Report the correct shared_cpu_map on big-cores

Currently on POWER9 SMT8 cores systems, in sysfs, we report the
shared_cache_map for L1 caches (both data and instruction) to be the
cpu-ids of the threads in SMT8 cores. This is incorrect since on
POWER9 SMT8 cores there are two groups of threads, each of which
shares its own L1 cache.

This patch addresses this by reporting the shared_cpu_map correctly in
sysfs for L1 caches.

Before the patch
   /sys/devices/system/cpu/cpu0/cache/index0/shared_cpu_map : 000000ff
   /sys/devices/system/cpu/cpu0/cache/index1/shared_cpu_map : 000000ff
   /sys/devices/system/cpu/cpu1/cache/index0/shared_cpu_map : 000000ff
   /sys/devices/system/cpu/cpu1/cache/index1/shared_cpu_map : 000000ff

After the patch
   /sys/devices/system/cpu/cpu0/cache/index0/shared_cpu_map : 00000055
   /sys/devices/system/cpu/cpu0/cache/index1/shared_cpu_map : 00000055
   /sys/devices/system/cpu/cpu1/cache/index0/shared_cpu_map : 000000aa
   /sys/devices/system/cpu/cpu1/cache/index1/shared_cpu_map : 000000aa

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc: Use cpu_smallcore_sibling_mask at SMT level on bigcores
Gautham R. Shenoy [Thu, 11 Oct 2018 05:33:02 +0000 (11:03 +0530)]
powerpc: Use cpu_smallcore_sibling_mask at SMT level on bigcores

POWER9 SMT8 cores consist of two groups of threads, where threads in
each group shares L1-cache. The scheduler is not aware of this
distinction as the current sched-domain hierarchy has all the threads
of the core defined at the SMT domain.

SMT  [Thread siblings of the SMT8 core]
DIE  [CPUs in the same die]
NUMA [All the CPUs in the system]

Due to this, we can observe run-to-run variance when we run a
multi-threaded benchmark bound to a single core based on how the
scheduler spreads the software threads across the two groups in the
core.

We fix this in this patch by defining each group of threads which
share L1-cache to be the SMT level. The group of threads in the SMT8
core is defined to be the CACHE level. The sched-domain hierarchy
after this patch will be :

SMT [Thread siblings in the core that share L1 cache]
CACHE  [Thread siblings that are in the SMT8 core]
DIE   [CPUs in the same die]
NUMA  [All the CPUs in the system]

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc: Detect the presence of big-cores via "ibm, thread-groups"
Gautham R. Shenoy [Thu, 11 Oct 2018 05:33:01 +0000 (11:03 +0530)]
powerpc: Detect the presence of big-cores via "ibm, thread-groups"

On IBM POWER9, the device tree exposes a property array identifed by
"ibm,thread-groups" which will indicate which groups of threads share
a particular set of resources.

As of today we only have one form of grouping identifying the group of
threads in the core that share the L1 cache, translation cache and
instruction data flow.

This patch adds helper functions to parse the contents of
"ibm,thread-groups" and populate a per-cpu variable to cache
information about siblings of each CPU that share the L1, traslation
cache and instruction data-flow.

It also defines a new global variable named "has_big_cores" which
indicates if the cores on this configuration have multiple groups of
threads that share L1 cache.

For each online CPU, it maintains a cpu_smallcore_mask, which
indicates the online siblings which share the L1-cache with it.

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc: Fix stackprotector detection for non-glibc toolchains
Michael Ellerman [Fri, 12 Oct 2018 11:09:09 +0000 (22:09 +1100)]
powerpc: Fix stackprotector detection for non-glibc toolchains

If GCC is not built with glibc support then we must explicitly tell it
which register to use for TLS mode stack protector, otherwise it will
error out and the cc-option check will fail.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/xmon: Show the stack protector canary in xmon
Michael Ellerman [Fri, 12 Oct 2018 02:58:52 +0000 (13:58 +1100)]
powerpc/xmon: Show the stack protector canary in xmon

This is helpful for debugging stack protector crashes.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc: Use SWITCH_FRAME_SIZE for prom and rtas entry
Joel Stanley [Fri, 12 Oct 2018 02:44:06 +0000 (13:14 +1030)]
powerpc: Use SWITCH_FRAME_SIZE for prom and rtas entry

Commit 6c1719942e19 ("powerpc/of: Remove useless register save/restore
when calling OF back") removed the saving of srr0 and srr1 when calling
into OpenFirmware. Commit e31aa453bbc4 ("powerpc: Use LOAD_REG_IMMEDIATE
only for constants on 64-bit") did the same for rtas.

This means we don't need to save the extra stack space and can use
the common SWITCH_FRAME_SIZE.

There were already no users of _SRR0 and _SRR1 so we can remove them
too.

Link: https://github.com/linuxppc/linux/issues/83
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/pseries/mobility: Extend start/stop topology update scope
Michael Bringmann [Tue, 9 Oct 2018 20:12:14 +0000 (15:12 -0500)]
powerpc/pseries/mobility: Extend start/stop topology update scope

The powerpc mobility code may receive RTAS requests to perform PRRN
(Platform Resource Reassignment Notification) topology changes at any
time, including during LPAR migration operations.

In some configurations where the affinity of CPUs or memory is being
changed on that platform, the PRRN requests may apply or refer to
outdated information prior to the complete update of the device-tree.

This patch changes the duration for which topology updates are
suppressed during LPAR migrations from just the rtas_ibm_suspend_me()
/ 'ibm,suspend-me' call(s) to cover the entire migration_store()
operation to allow all changes to the device-tree to be applied prior
to accepting and applying any PRRN requests.

For tracking purposes, pr_info notices are added to the functions
start_topology_update() and stop_topology_update() of 'numa.c'.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/Makefile: Fix PPC_BOOK3S_64 ASFLAGS
Joel Stanley [Thu, 11 Oct 2018 02:43:03 +0000 (13:13 +1030)]
powerpc/Makefile: Fix PPC_BOOK3S_64 ASFLAGS

Ever since commit 15a3204d24a3 ("powerpc/64s: Set assembler machine type
to POWER4") we force -mpower4 to be passed to the assembler
irrespective of the CFLAGS used (for Book3s 64).

When building a powerpc64 kernel with clang, clang will not add -many
to the assembler flags, so any instructions that the compiler has
generated that are not available on power4 will cause an error:

  /usr/bin/as -a64 -mppc64 -mlittle-endian -mpower8 \
   -I ./arch/powerpc/include -I ./arch/powerpc/include/generated \
   -I ./include -I ./arch/powerpc/include/uapi \
   -I ./arch/powerpc/include/generated/uapi -I ./include/uapi \
   -I ./include/generated/uapi -I arch/powerpc -I arch/powerpc \
   -maltivec -mpower4 -o init/do_mounts.o /tmp/do_mounts-3b0a3d.s
  /tmp/do_mounts-51ce54.s:748: Error: unrecognized opcode: `isel'

GCC does include -many, so the GCC driven gas call will succeed:

  as -v -I ./arch/powerpc/include -I ./arch/powerpc/include/generated -I
  ./include -I ./arch/powerpc/include/uapi
  -I ./arch/powerpc/include/generated/uapi -I ./include/uapi
  -I ./include/generated/uapi -I arch/powerpc -I arch/powerpc
   -a64 -mpower8 -many -mlittle -maltivec -mpower4 -o init/do_mounts.o

Note that isel is power7 and above for IBM CPUs. GCC only generates it
for Power9 and above, but the above test was run against the clang
generated assembly.

Peter Bergner explains:

  When using -many -mpower4, gas will first try and find a matching
  power4 mnemonic and failing that, it will then allow any valid
  mnemonic that gas knows about. GCC's use of -many predates me
  though.

  IIRC, Alan looked at trying to remove it, but I forget why he
  didn't. Could be either a gcc or gas issue at the time. I'm not sure
  whether issue still exists or not. He and I have modified how gas
  works internally a fair amount since he tried removing gcc use of
  -many.

  I will also note that when using -many, gas will choose the first
  mnemonic that matches in the mnemonic table and we have (mostly)
  sorted the table so that server mnemonics show up earlier in the
  table than other mnemonics, so they'll be seen/chosen first.

By explicitly setting -many we can build with Clang and GCC while
retaining the -mpower4 option.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/pseries/memory-hotplug: Fix return value type of find_aa_index
YueHaibing [Tue, 9 Oct 2018 13:59:13 +0000 (21:59 +0800)]
powerpc/pseries/memory-hotplug: Fix return value type of find_aa_index

The variable 'aa_index' is defined as an unsigned value in
update_lmb_associativity_index(), but find_aa_index() may return -1
when dlpar_clone_property() fails. So change find_aa_index() to return
a bool, which indicates whether 'aa_index' was found or not.

Fixes: c05a5a40969e ("powerpc/pseries: Dynamic add entires to associativity lookup array")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Nathan Fontenot nfont@linux.vnet.ibm.com>
[mpe: Tweak changelog, rename is_found to just found]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Cleanup control flow in eeh_handle_normal_event()
Sam Bobroff [Wed, 12 Sep 2018 01:23:33 +0000 (11:23 +1000)]
powerpc/eeh: Cleanup control flow in eeh_handle_normal_event()

Rather than mixing "if (state)" blocks and gotos, convert entirely to
"if (state)" blocks to make the state machine behaviour clearer.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Cleanup eeh_ops.wait_state()
Sam Bobroff [Wed, 12 Sep 2018 01:23:32 +0000 (11:23 +1000)]
powerpc/eeh: Cleanup eeh_ops.wait_state()

The wait_state member of eeh_ops does not need to be platform
dependent; it's just logic around eeh_ops.get_state(). Therefore,
merge the two (slightly different!) platform versions into a new
function, eeh_wait_state() and remove the eeh_ops member.

While doing this, also correct:
* The wait logic, so that it never waits longer than max_wait.
* The wait logic, so that it never waits less than
  EEH_STATE_MIN_WAIT_TIME.
* One call site where the result is treated like a bit field before
  it's checked for negative error values.
* In pseries_eeh_get_state(), rename the "state" parameter to "delay"
  because that's what it is.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Cleanup eeh_pe_state_mark()
Sam Bobroff [Wed, 12 Sep 2018 01:23:31 +0000 (11:23 +1000)]
powerpc/eeh: Cleanup eeh_pe_state_mark()

Currently, eeh_pe_state_mark() marks a PE (and it's children) with a
state and then performs additional processing if that state included
EEH_PE_ISOLATED.

The state parameter is always a constant at the call site, so
rearrange eeh_pe_state_mark() into two functions and just call the
appropriate one at each site.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Cleanup unnecessary eeh_pe_state_mark_with_cfg()
Sam Bobroff [Wed, 12 Sep 2018 01:23:30 +0000 (11:23 +1000)]
powerpc/eeh: Cleanup unnecessary eeh_pe_state_mark_with_cfg()

The function eeh_pe_state_mark_with_cfg() just performs the work of
eeh_pe_state_mark() and then, conditionally, the work of
eeh_pe_state_clear(). However it is only ever called with a constant
state such that the condition is always true, so replace it by direct
calls.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Cleanup eeh_enabled()
Sam Bobroff [Wed, 12 Sep 2018 01:23:29 +0000 (11:23 +1000)]
powerpc/eeh: Cleanup eeh_enabled()

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Cleanup logic in eeh_rmv_from_parent_pe()
Sam Bobroff [Wed, 12 Sep 2018 01:23:28 +0000 (11:23 +1000)]
powerpc/eeh: Cleanup logic in eeh_rmv_from_parent_pe()

Move the call to eeh_dev_to_pe() up, so that later it's clear that
"pe" isn't NULL.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Cleanup field names in eeh_rmv_data
Sam Bobroff [Wed, 12 Sep 2018 01:23:27 +0000 (11:23 +1000)]
powerpc/eeh: Cleanup field names in eeh_rmv_data

Change the name of the fields in eeh_rmv_data to clarify their usage.

Change "edev_list" to "removed_vf_list" because it does not contain
generic edevs, but rather only edevs that contain virtual functions
(which need to be removed during recovery).

Similarly, change "removed" to "removed_dev_count" because it is a
count of any removed devices, not just those in the above list.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Cleanup list_head field names
Sam Bobroff [Wed, 12 Sep 2018 01:23:26 +0000 (11:23 +1000)]
powerpc/eeh: Cleanup list_head field names

Instances of struct eeh_pe are placed in a tree structure using the
fields "child_list" and "child", so place these next to each other
in the definition.

The field "child" is a list entry, so remove the unnecessary and
misleading use of the list initializer, LIST_HEAD(), on it.

The eeh_dev struct contains two list entry fields, called "list" and
"rmv_list". Rename them to "entry" and "rmv_entry" and, as above, stop
initializing them with LIST_HEAD().

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Cleanup eeh_add_virt_device()
Sam Bobroff [Wed, 12 Sep 2018 01:23:25 +0000 (11:23 +1000)]
powerpc/eeh: Cleanup eeh_add_virt_device()

Remove the unnecessary cast through void * on the first parameter and
remove the unused second parameter (always NULL).

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Cleanup unused field in eeh_dev
Sam Bobroff [Wed, 12 Sep 2018 01:23:24 +0000 (11:23 +1000)]
powerpc/eeh: Cleanup unused field in eeh_dev

The 'bus' member of struct eeh_dev is assigned to once but never used,
so remove it.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Cleanup EEH_POSTPONED_PROBE
Sam Bobroff [Wed, 12 Sep 2018 01:23:23 +0000 (11:23 +1000)]
powerpc/eeh: Cleanup EEH_POSTPONED_PROBE

Currently a flag, EEH_POSTPONED_PROBE, is used to prevent an incorrect
message "EEH: No capable adapters found" from being displayed during
the boot of powernv systems.

It is necessary because, on powernv, the call to eeh_probe_devices()
made from eeh_init() is too early and EEH can't yet be enabled. A
second call is made later from eeh_pnv_post_init(), which succeeds.

(On pseries, the first call succeeds because PCI devices are set up
early enough and no second call is made.)

This can be simplified by moving the early call to eeh_probe_devices()
from eeh_init() (where it's seen by both platforms) to
pSeries_final_fixup(), so that each platform only calls
eeh_probe_devices() once, at a point where it can succeed.
This is slightly later in the boot sequence, but but still early
enough and it is now in the same place in the sequence for both
platforms (the pcibios_fixup hook).

The display of the message can be cleaned up as well, by moving it
into eeh_probe_devices().

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Fix use of EEH_PE_KEEP on wrong field
Sam Bobroff [Wed, 12 Sep 2018 01:23:22 +0000 (11:23 +1000)]
powerpc/eeh: Fix use of EEH_PE_KEEP on wrong field

eeh_add_to_parent_pe() sometimes removes the EEH_PE_KEEP flag, but it
incorrectly removes it from pe->type, instead of pe->state.

However, rather than clearing it from the correct field, remove it.
Inspection of the code shows that it can't ever have had any effect
(even if it had been cleared from the correct field), because the
field is never tested after it is cleared by the statement in
question.

The clear statement was added by commit 807a827d4e74 ("powerpc/eeh:
Keep PE during hotplug"), but it didn't explain why it was necessary.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Fix null deref for devices removed during EEH
Sam Bobroff [Wed, 12 Sep 2018 01:23:21 +0000 (11:23 +1000)]
powerpc/eeh: Fix null deref for devices removed during EEH

If a device is removed during EEH processing (either by a driver's
handler or as part of recovery), it can lead to a null dereference
in eeh_pe_report_edev().

To handle this, skip devices that have been removed.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/eeh: Fix possible null deref in eeh_dump_dev_log()
Sam Bobroff [Wed, 12 Sep 2018 01:23:20 +0000 (11:23 +1000)]
powerpc/eeh: Fix possible null deref in eeh_dump_dev_log()

If an error occurs during an unplug operation, it's possible for
eeh_dump_dev_log() to be called when edev->pdn is null, which
currently leads to dereferencing a null pointer.

Handle this by skipping the error log for those devices.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/boot: Build boot wrapper with optimisations
Joel Stanley [Wed, 10 Oct 2018 02:45:23 +0000 (13:15 +1030)]
powerpc/boot: Build boot wrapper with optimisations

The boot wrapper is currently built with -Os. By building with O2 we
can meaningfully reduce the time decompressing the kernel.

I tested by comparing 10 runs of each option in Qemu and on hardware.
The kernel is compressed with KERNEL_XZ built with GCC 8.2.0-7ubuntu1.
The values are counts of the timebase.

Qemu TCG powernv Power8:

              Os            O2            O3
 median       10221123889   6201518438    6568186825
 stddev        1361267211    429090641     657930076
 improvement                    39.33%        35.74%

Palmetto Power8:

              Os            O2            O3
 median           50279         50599          35790
 stddev       992144533     627130655      623721078
 improvement                   36.79%         37.13%

Romulus Power9:

              Os            O2            O3
 median       670312391     454733720      448881398
 stddev          157569        107276         108760
 improvement                   32.16%         33.03%

TCG was quite noisy, with every few runs producing an outlier. Even so,
O2 is faster than O3. On hardware the numbers were less noisy and O3 is
slightly faster than O2.

The wrapper size increases when moving from Os. Comparing zImage.epapr
to the existing Os build using bloat-o-meter:

  Before=43401, After=56837 (13KB), chg +30.96%
  Before=43401, After=64305 (20KB), chg +48.16%

I chose O2 for a balance between Qemu and hardware speed up.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/boot: Disable vector instructions
Joel Stanley [Wed, 10 Oct 2018 02:45:22 +0000 (13:15 +1030)]
powerpc/boot: Disable vector instructions

This will avoid auto-vectorisation when building with higher
optimisation levels.

We don't know if the machine can support VSX and even if it's present
it's probably not going to be enabled at this point in boot.

These flag were both added prior to GCC 4.6 which is the minimum
compiler version supported by upstream, thanks to Segher for the
details.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/boot: Fix opal console in boot wrapper
Joel Stanley [Tue, 9 Oct 2018 23:28:03 +0000 (09:58 +1030)]
powerpc/boot: Fix opal console in boot wrapper

As of commit 10c77dba40ff ("powerpc/boot: Fix build failure in 32-bit
boot wrapper") the opal code is hidden behind CONFIG_PPC64_BOOT_WRAPPER,
but the boot wrapper avoids include/linux, so it does not get the normal
Kconfig flags.

We can drop the guard entirely as in commit f8e8e69cea49 ("powerpc/boot:
Only build OPAL code when necessary") the makefile only includes opal.c
in the build if CONFIG_PPC64_BOOT_WRAPPER is set.

Fixes: 10c77dba40ff ("powerpc/boot: Fix build failure in 32-bit boot wrapper")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/boot: Expose Kconfig symbols to wrapper
Joel Stanley [Tue, 9 Oct 2018 23:28:02 +0000 (09:58 +1030)]
powerpc/boot: Expose Kconfig symbols to wrapper

Currently the wrapper is built without including anything in
$(src)/include/, which means there are no CONFIG_ symbols defined.
This means the platform specific serial drivers were never enabled.

We now copy the definitions into the boot directory, so any C file can
now include autoconf.h to depend on configuration options.

Fixes: 866bfc75f40e ("powerpc: conditionally compile platform-specific serial drivers")
Signed-off-by: Joel Stanley <joel@jms.id.au>
[mpe: Fix to use $(objtree) to find autoconf.h]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc: remove redundant 'default n' from Kconfig-s
Bartlomiej Zolnierkiewicz [Tue, 9 Oct 2018 15:39:46 +0000 (17:39 +0200)]
powerpc: remove redundant 'default n' from Kconfig-s

'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.

Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOO
is not set' for visible symbols") the Kconfig behavior is the same
regardless of 'default n' being present or not:

    ...
    One side effect of (and the main motivation for) this change is making
    the following two definitions behave exactly the same:

        config FOO
                bool

        config FOO
                bool
                default n

    With this change, neither of these will generate a
    '# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
    That might make it clearer to people that a bare 'default n' is
    redundant.
    ...

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/rtasd: Improve unknown error logging
Oliver O'Halloran [Wed, 10 Oct 2018 05:23:02 +0000 (16:23 +1100)]
powerpc/rtasd: Improve unknown error logging

Currently when we get an unknown RTAS event it prints the type as
"Unknown" and no other useful information. Add the raw type code to the
log message so that we have something to work off.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc: Disable -Wbuiltin-requires-header when setjmp is used
Joel Stanley [Mon, 17 Sep 2018 07:46:21 +0000 (17:16 +0930)]
powerpc: Disable -Wbuiltin-requires-header when setjmp is used

The powerpc kernel uses setjmp which causes a warning when building
with clang:

  In file included from arch/powerpc/xmon/xmon.c:51:
  ./arch/powerpc/include/asm/setjmp.h:15:13: error: declaration of
  built-in function 'setjmp' requires inclusion of the header <setjmp.h>
        [-Werror,-Wbuiltin-requires-header]
  extern long setjmp(long *);
              ^
  ./arch/powerpc/include/asm/setjmp.h:16:13: error: declaration of
  built-in function 'longjmp' requires inclusion of the header <setjmp.h>
        [-Werror,-Wbuiltin-requires-header]
  extern void longjmp(long *, long);
              ^

This *is* the header and we're not using the built-in setjump but
rather the one in arch/powerpc/kernel/misc.S. As the compiler warning
does not make sense, it for the files where setjmp is used.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
[mpe: Move subdir-ccflags in xmon/Makefile to not clobber -Werror]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc: Fix signedness bug in update_flash_db()
Dan Carpenter [Mon, 1 Oct 2018 16:44:58 +0000 (19:44 +0300)]
powerpc: Fix signedness bug in update_flash_db()

The "count < sizeof(struct os_area_db)" comparison is type promoted to
size_t so negative values of "count" are treated as very high values
and we accidentally return success instead of a negative error code.

This doesn't really change runtime much but it fixes a static checker
warning.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/perf: Quiet IMC PMU registration message
Joel Stanley [Tue, 9 Oct 2018 06:20:38 +0000 (16:50 +1030)]
powerpc/perf: Quiet IMC PMU registration message

On a Power9 box we get a few screens full of these on boot. Drop
them to pr_debug.

  [    5.993645] nest_centaur6_imc performance monitor hardware support registered
  [    5.993728] nest_centaur7_imc performance monitor hardware support registered
  [    5.996510] core_imc performance monitor hardware support registered
  [    5.996569] nest_mba0_imc performance monitor hardware support registered
  [    5.996631] nest_mba1_imc performance monitor hardware support registered
  [    5.996685] nest_mba2_imc performance monitor hardware support registered

Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Reviewed-by: Stewart Smith <stewart@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/process: Constify the number of insns printed by show instructions functions.
Christophe Leroy [Sat, 6 Oct 2018 16:51:16 +0000 (16:51 +0000)]
powerpc/process: Constify the number of insns printed by show instructions functions.

instructions_to_print var is assigned value 16 and there is no
way to change it.

This patch replaces it by a constant.

Reviewed-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/process: Fix interleaved output in show_user_instructions()
Christophe Leroy [Sat, 6 Oct 2018 16:51:14 +0000 (16:51 +0000)]
powerpc/process: Fix interleaved output in show_user_instructions()

When two processes crash at the same time, we sometimes encounter
interleaving in the middle of a line:

  init[1]: segfault (11) at 0 nip 0 lr 0 code 1
  init[1]: code: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
  init[74]: segfault (11) at 10a74 nip 1000c198 lr 100078c8 code 1 in sh[10000000+14000]
  XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
  init[1]: code: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
  init[74]: code: 90010024 bf61000c 91490a7c 3fa01002 3be00000 7d3e4b78 3bbd0c20 3b600000
  init[74]: code: 3b9d0040 7c7fe02e 2f830000 419e0028 <892300002f890000 41be001c 4b7f6e79

This patch fixes it by preparing complete lines in a buffer and
printing it at once.

Fixes: 88b0fe1757359 ("powerpc: Add show_user_instructions()")
Reviewed-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Use seq_buf_printf() not seq_buf_puts() which doesn't NULL terminate]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/process: Add missing include of stacktrace.h
Christophe Leroy [Tue, 9 Oct 2018 05:46:25 +0000 (16:46 +1100)]
powerpc/process: Add missing include of stacktrace.h

As spotted by sparse:

  arch/powerpc/kernel/process.c:1302:6: warning: symbol 'show_user_instructions' was not declared. Should it be static?

Fixes: 88b0fe1757359 ("powerpc: Add show_user_instructions()")
Reviewed-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/process: Fix sparse address space warnings
Christophe Leroy [Sat, 6 Oct 2018 16:51:12 +0000 (16:51 +0000)]
powerpc/process: Fix sparse address space warnings

This patch fixes the following warnings, which are leftovers
from when __get_user() was replaced by probe_kernel_address().

arch/powerpc/kernel/process.c:1287:22: warning: incorrect type in argument 2 (different address spaces)
arch/powerpc/kernel/process.c:1287:22:    expected void const *src
arch/powerpc/kernel/process.c:1287:22:    got unsigned int [noderef] <asn:1>*<noident>
arch/powerpc/kernel/process.c:1319:21: warning: incorrect type in argument 2 (different address spaces)
arch/powerpc/kernel/process.c:1319:21:    expected void const *src
arch/powerpc/kernel/process.c:1319:21:    got unsigned int [noderef] <asn:1>*<noident>

Fixes: 7b051f665c32d ("powerpc: Use probe_kernel_address in show_instructions")
Reviewed-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/64: properly initialise the stackprotector canary on SMP.
Christophe Leroy [Sat, 13 Oct 2018 09:45:12 +0000 (09:45 +0000)]
powerpc/64: properly initialise the stackprotector canary on SMP.

commit 06ec27aea9fc ("powerpc/64: add stack protector support")
doesn't initialise the stack canary on SMP secondary CPU's paca,
leading to the following false positive report from the
stack protector.

smp: Bringing up secondary CPUs ...
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: __schedule+0x978/0xa80
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.0-rc7-next-20181010-autotest-autotest #1
Call Trace:
[c000001fed5b3bf0] [c000000000a0ef3c] dump_stack+0xb0/0xf4 (unreliable)
[c000001fed5b3c30] [c0000000000f9d68] panic+0x140/0x308
[c000001fed5b3cc0] [c0000000000f9844] __stack_chk_fail+0x24/0x30
[c000001fed5b3d20] [c000000000a2c3a8] __schedule+0x978/0xa80
[c000001fed5b3e00] [c000000000a2c9b4] schedule_idle+0x34/0x60
[c000001fed5b3e30] [c00000000013d344] do_idle+0x224/0x3d0
[c000001fed5b3ec0] [c00000000013d6e0] cpu_startup_entry+0x30/0x50
[c000001fed5b3ef0] [c000000000047f34] start_secondary+0x4d4/0x520
[c000001fed5b3f90] [c00000000000b370] start_secondary_prolog+0x10/0x14

This patch properly initialises the stack_canary of the secondary
idle tasks.

Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Fixes: 06ec27aea9fc ("powerpc/64: add stack protector support")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agoMerge branch 'fixes' into next
Michael Ellerman [Tue, 9 Oct 2018 05:51:05 +0000 (16:51 +1100)]
Merge branch 'fixes' into next

Merge our fixes branch. It has a few important fixes that are needed for
futher testing and also some commits that will conflict with content in
next.

6 years agomacintosh/via-macii, macintosh/adb-iop: Clean up whitespace
Finn Thain [Wed, 12 Sep 2018 00:18:44 +0000 (20:18 -0400)]
macintosh/via-macii, macintosh/adb-iop: Clean up whitespace

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agomacintosh/via-macii, macintosh/adb-iop: Modernize printk calls
Finn Thain [Wed, 12 Sep 2018 00:18:44 +0000 (20:18 -0400)]
macintosh/via-macii, macintosh/adb-iop: Modernize printk calls

Add missing severity level to log messages.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agomacintosh/via-macii: Simplify locking
Finn Thain [Wed, 12 Sep 2018 00:18:44 +0000 (20:18 -0400)]
macintosh/via-macii: Simplify locking

Modifying the request queue or changing the current state requires
mutual exclusion. Use local_irq_disable() consistently for this
rather than disabling the ADB interrupt. This simplifies the locking
scheme and brings via-macii into line with the other ADB drivers.

Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agomacintosh/via-macii: Remove BUG_ON assertions
Finn Thain [Wed, 12 Sep 2018 00:18:44 +0000 (20:18 -0400)]
macintosh/via-macii: Remove BUG_ON assertions

The BUG_ON assertions I added to the via-macii driver over a decade ago
haven't fired AFAIK. Some can never fire (by inspection). One assertion
checks for a NULL pointer, but that would merely substitute a BUG crash
for an Oops crash. Remove the pointless BUG_ON assertions and replace
the others with a WARN_ON and an array bounds check.

Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agomacintosh/via-macii: Synchronous bus reset
Finn Thain [Wed, 12 Sep 2018 00:18:44 +0000 (20:18 -0400)]
macintosh/via-macii: Synchronous bus reset

Make the reset operation synchronous, like the other ADB drivers.
The reset request is static data but callers may not know that.
This way the struct is not in use when the reset method returns.

Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agomacintosh/adb: Rework printk output again
Finn Thain [Wed, 12 Sep 2018 00:18:44 +0000 (20:18 -0400)]
macintosh/adb: Rework printk output again

Avoid the KERN_CONT problem by avoiding message fragments. The problem
arises during async ADB bus probing, when ADB messages may get mixed up
with other messages. See also, commit 4bcc595ccd80 ("printk: reinstate
KERN_CONT for printing continuation lines").

Remove a number of printk() continuation lines by logging handler
changes in adb_try_handler_change() instead.

This patch addresses the problematic use of "\n" at the beginning of
pr_cont() messages, which got overlooked in commit f2be6295684b
("macintosh/adb: Properly mark continued kernel messages").

That commit also changed printk(KERN_DEBUG ...) to pr_debug(...), which
hinders work on low-level ADB driver bugs. Revert that change.

Cc: Andreas Schwab <schwab@linux-m68k.org>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agomacintosh: Use common code to access RTC
Finn Thain [Wed, 12 Sep 2018 00:18:44 +0000 (20:18 -0400)]
macintosh: Use common code to access RTC

Now that the 68k Mac port has adopted the via-pmu driver, the same RTC
code can be shared between m68k and powerpc. Replace duplicated code in
arch/powerpc and arch/m68k with common RTC accessors for Cuda and PMU.

Drop the problematic WARN_ON which was introduced in commit 22db552b50fa
("powerpc/powermac: Fix rtc read/write functions").

Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/numa: Skip onlining a offline node in kdump path
Srikar Dronamraju [Fri, 28 Sep 2018 03:47:32 +0000 (09:17 +0530)]
powerpc/numa: Skip onlining a offline node in kdump path

With commit 2ea626306810 ("powerpc/topology: Get topology for shared
processors at boot"), kdump kernel on shared LPAR may crash.

The necessary conditions are
- Shared LPAR with at least 2 nodes having memory and CPUs.
- Memory requirement for kdump kernel must be met by the first N-1
  nodes where there are at least N nodes with memory and CPUs.

Example numactl of such a machine.
  $ numactl -H
  available: 5 nodes (0,2,5-7)
  node 0 cpus:
  node 0 size: 0 MB
  node 0 free: 0 MB
  node 2 cpus:
  node 2 size: 255 MB
  node 2 free: 189 MB
  node 5 cpus: 24 25 26 27 28 29 30 31
  node 5 size: 4095 MB
  node 5 free: 4024 MB
  node 6 cpus: 0 1 2 3 4 5 6 7 16 17 18 19 20 21 22 23
  node 6 size: 6353 MB
  node 6 free: 5998 MB
  node 7 cpus: 8 9 10 11 12 13 14 15 32 33 34 35 36 37 38 39
  node 7 size: 7640 MB
  node 7 free: 7164 MB
  node distances:
  node   0   2   5   6   7
    0:  10  40  40  40  40
    2:  40  10  40  40  40
    5:  40  40  10  40  40
    6:  40  40  40  10  20
    7:  40  40  40  20  10

Steps to reproduce.
1. Load / start kdump service.
2. Trigger a kdump (for example : echo c > /proc/sysrq-trigger)

When booting a kdump kernel with 2048M:

  kexec: Starting switchover sequence.
  I'm in purgatory
  Using 1TB segments
  hash-mmu: Initializing hash mmu with SLB
  Linux version 4.19.0-rc5-master+ (srikar@linux-xxu6) (gcc version 4.8.5 (SUSE Linux)) #1 SMP Thu Sep 27 19:45:00 IST 2018
  Found initrd at 0xc000000009e70000:0xc00000000ae554b4
  Using pSeries machine description
  -----------------------------------------------------
  ppc64_pft_size    = 0x1e
  phys_mem_size     = 0x88000000
  dcache_bsize      = 0x80
  icache_bsize      = 0x80
  cpu_features      = 0x000000ff8f5d91a7
    possible        = 0x0000fbffcf5fb1a7
    always          = 0x0000006f8b5c91a1
  cpu_user_features = 0xdc0065c2 0xef000000
  mmu_features      = 0x7c006001
  firmware_features = 0x00000007c45bfc57
  htab_hash_mask    = 0x7fffff
  physical_start    = 0x8000000
  -----------------------------------------------------
  numa:   NODE_DATA [mem 0x87d5e300-0x87d67fff]
  numa:     NODE_DATA(0) on node 6
  numa:   NODE_DATA [mem 0x87d54600-0x87d5e2ff]
  Top of RAM: 0x88000000, Total RAM: 0x88000000
  Memory hole size: 0MB
  Zone ranges:
    DMA      [mem 0x0000000000000000-0x0000000087ffffff]
    DMA32    empty
    Normal   empty
  Movable zone start for each node
  Early memory node ranges
    node   6: [mem 0x0000000000000000-0x0000000087ffffff]
  Could not find start_pfn for node 0
  Initmem setup node 0 [mem 0x0000000000000000-0x0000000000000000]
  On node 0 totalpages: 0
  Initmem setup node 6 [mem 0x0000000000000000-0x0000000087ffffff]
  On node 6 totalpages: 34816

  Unable to handle kernel paging request for data at address 0x00000060
  Faulting instruction address: 0xc000000008703a54
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 11 PID: 1 Comm: swapper/11 Not tainted 4.19.0-rc5-master+ #1
  NIP:  c000000008703a54 LR: c000000008703a38 CTR: 0000000000000000
  REGS: c00000000b673440 TRAP: 0380   Not tainted  (4.19.0-rc5-master+)
  MSR:  8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24022022  XER: 20000002
  CFAR: c0000000086fc238 IRQMASK: 0
  GPR00: c000000008703a38 c00000000b6736c0 c000000009281900 0000000000000000
  GPR04: 0000000000000000 0000000000000000 fffffffffffff001 c00000000b660080
  GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000220
  GPR12: 0000000000002200 c000000009e51400 0000000000000000 0000000000000008
  GPR16: 0000000000000000 c000000008c152e8 c000000008c152a8 0000000000000000
  GPR20: c000000009422fd8 c000000009412fd8 c000000009426040 0000000000000008
  GPR24: 0000000000000000 0000000000000000 c000000009168bc8 c000000009168c78
  GPR28: c00000000b126410 0000000000000000 c00000000916a0b8 c00000000b126400
  NIP [c000000008703a54] bus_add_device+0x84/0x1e0
  LR [c000000008703a38] bus_add_device+0x68/0x1e0
  Call Trace:
  [c00000000b6736c0] [c000000008703a38] bus_add_device+0x68/0x1e0 (unreliable)
  [c00000000b673740] [c000000008700194] device_add+0x454/0x7c0
  [c00000000b673800] [c00000000872e660] __register_one_node+0xb0/0x240
  [c00000000b673860] [c00000000839a6bc] __try_online_node+0x12c/0x180
  [c00000000b673900] [c00000000839b978] try_online_node+0x58/0x90
  [c00000000b673930] [c0000000080846d8] find_and_online_cpu_nid+0x158/0x190
  [c00000000b673a10] [c0000000080848a0] numa_update_cpu_topology+0x190/0x580
  [c00000000b673c00] [c000000008d3f2e4] smp_cpus_done+0x94/0x108
  [c00000000b673c70] [c000000008d5c00c] smp_init+0x174/0x19c
  [c00000000b673d00] [c000000008d346b8] kernel_init_freeable+0x1e0/0x450
  [c00000000b673dc0] [c0000000080102e8] kernel_init+0x28/0x160
  [c00000000b673e30] [c00000000800b65c] ret_from_kernel_thread+0x5c/0x80
  Instruction dump:
  60000000 60000000 e89e0020 7fe3fb78 4bff87d5 60000000 7c7d1b79 4082008c
  e8bf0050 e93e0098 3b9f0010 2fa50000 <e869006038630018 419e0114 7f84e378
  ---[ end trace 593577668c2daa65 ]---

However a regular kernel with 4096M (2048 gets reserved for crash
kernel) boots properly.

Unlike regular kernels, which mark all available nodes as online,
kdump kernel only marks just enough nodes as online and marks the rest
as offline at boot. However kdump kernel boots with all available
CPUs. With Commit 2ea626306810 ("powerpc/topology: Get topology for
shared processors at boot"), all CPUs are onlined on their respective
nodes at boot time. try_online_node() tries to online the offline
nodes but fails as all needed subsystems are not yet initialized.

As part of fix, detect and skip early onlining of a offline node.

Fixes: 2ea626306810 ("powerpc/topology: Get topology for shared processors at boot")
Reported-by: Pavithra Prakash <pavrampu@in.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc: Don't print kernel instructions in show_user_instructions()
Michael Ellerman [Fri, 5 Oct 2018 06:43:55 +0000 (16:43 +1000)]
powerpc: Don't print kernel instructions in show_user_instructions()

Recently we implemented show_user_instructions() which dumps the code
around the NIP when a user space process dies with an unhandled
signal. This was modelled on the x86 code, and we even went so far as
to implement the exact same bug, namely that if the user process
crashed with its NIP pointing into the kernel we will dump kernel text
to dmesg. eg:

  bad-bctr[2996]: segfault (11) at c000000000010000 nip c000000000010000 lr 12d0b0894 code 1
  bad-bctr[2996]: code: fbe10068 7cbe2b78 7c7f1b78 fb610048 38a10028 38810020 fb810050 7f8802a6
  bad-bctr[2996]: code: 3860001c f8010080 48242371 60000000 <7c7b1b794082002c e8010080 eb610048

This was discovered on x86 by Jann Horn and fixed in commit
342db04ae712 ("x86/dumpstack: Don't dump kernel memory based on usermode RIP").

Fix it by checking the adjusted NIP value (pc) and number of
instructions against USER_DS, and bail if we fail the check, eg:

  bad-bctr[2969]: segfault (11) at c000000000010000 nip c000000000010000 lr 107930894 code 1
  bad-bctr[2969]: Bad NIP, not dumping instructions.

Fixes: 88b0fe175735 ("powerpc: Add show_user_instructions()")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/64s/radix: Explicitly flush ERAT with local LPID invalidation
Nicholas Piggin [Mon, 27 Aug 2018 03:03:02 +0000 (13:03 +1000)]
powerpc/64s/radix: Explicitly flush ERAT with local LPID invalidation

Local radix TLB flush operations that operate on congruence classes
have explicit ERAT flushes for POWER9. The process scoped LPID flush
did not have a flush, so add it.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/64s/hash: Do not use PPC_INVALIDATE_ERAT on CPUs before POWER9
Nicholas Piggin [Mon, 27 Aug 2018 03:03:01 +0000 (13:03 +1000)]
powerpc/64s/hash: Do not use PPC_INVALIDATE_ERAT on CPUs before POWER9

PPC_INVALIDATE_ERAT is slbia IH=7 which is a new variant introduced
with POWER9, and the result is undefined on earlier CPUs.

Commits 7b9f71f974 ("powerpc/64s: POWER9 machine check handler") and
d4748276ae ("powerpc/64s: Improve local TLB flush for boot and MCE on
POWER9") caused POWER7/8 code to use this instruction. Remove it. An
ERAT flush can be made by invalidatig the SLB, but before POWER9 that
requires a flush and rebolt.

Fixes: 7b9f71f974 ("powerpc/64s: POWER9 machine check handler")
Fixes: d4748276ae ("powerpc/64s: Improve local TLB flush for boot and MCE on POWER9")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/time: Add set_state_oneshot_stopped decrementer callback
Anton Blanchard [Mon, 1 Oct 2018 23:01:05 +0000 (09:01 +1000)]
powerpc/time: Add set_state_oneshot_stopped decrementer callback

If CONFIG_PPC_WATCHDOG is enabled we always cap the decrementer to
0x7fffffff:

       if (IS_ENABLED(CONFIG_PPC_WATCHDOG))
                set_dec(0x7fffffff);
        else
                set_dec(decrementer_max);

If there are no future events, we don't reprogram the decrementer
after this and we end up with 0x7fffffff even on a large decrementer
capable system.

As suggested by Nick, add a set_state_oneshot_stopped callback
so we program the decrementer with decrementer_max if there are
no future events.

Signed-off-by: Anton Blanchard <anton@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer
Anton Blanchard [Mon, 1 Oct 2018 23:01:04 +0000 (09:01 +1000)]
powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer

We currently cap the decrementer clockevent at 4 seconds, even on systems
with large decrementer support. Fix this by converting the code to use
clockevents_register_device() which calculates the upper bound based on
the max_delta passed in.

Signed-off-by: Anton Blanchard <anton@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/powernv/npu: Remove atsd_threshold debugfs setting
Mark Hairgrove [Wed, 3 Oct 2018 18:51:34 +0000 (11:51 -0700)]
powerpc/powernv/npu: Remove atsd_threshold debugfs setting

This threshold is no longer used now that all invalidates issue a single
ATSD to each active NPU.

Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/powernv/npu: Use size-based ATSD invalidates
Mark Hairgrove [Wed, 3 Oct 2018 18:51:33 +0000 (11:51 -0700)]
powerpc/powernv/npu: Use size-based ATSD invalidates

Prior to this change only two types of ATSDs were issued to the NPU:
invalidates targeting a single page and invalidates targeting the whole
address space. The crossover point happened at the configurable
atsd_threshold which defaulted to 2M. Invalidates that size or smaller
would issue per-page invalidates for the whole range.

The NPU supports more invalidation sizes however: 64K, 2M, 1G, and all.
These invalidates target addresses aligned to their size. 2M is a common
invalidation size for GPU-enabled applications because that is a GPU
page size, so reducing the number of invalidates by 32x in that case is a
clear improvement.

ATSD latency is high in general so now we always issue a single invalidate
rather than multiple. This will over-invalidate in some cases, but for any
invalidation size over 2M it matches or improves the prior behavior.
There's also an improvement for single-page invalidates since the prior
version issued two invalidates for that case instead of one.

With this change all issued ATSDs now perform a flush, so the flush
parameter has been removed from all the helpers.

To show the benefit here are some performance numbers from a
microbenchmark which creates a 1G allocation then uses mprotect with
PROT_NONE to trigger invalidates in strides across the allocation.

One NPU (1 GPU):

         mprotect rate (GB/s)
Stride   Before      After      Speedup
64K         5.3        5.6           5%
1M         39.3       57.4          46%
2M         49.7       82.6          66%
4M        286.6      285.7           0%

Two NPUs (6 GPUs):

         mprotect rate (GB/s)
Stride   Before      After      Speedup
64K         6.5        7.4          13%
1M         33.4       67.9         103%
2M         38.7       93.1         141%
4M        356.7      354.6          -1%

Anything over 2M is roughly the same as before since both cases issue a
single ATSD.

Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com>
Reviewed-By: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc/powernv/npu: Reduce eieio usage when issuing ATSD invalidates
Mark Hairgrove [Wed, 3 Oct 2018 18:51:32 +0000 (11:51 -0700)]
powerpc/powernv/npu: Reduce eieio usage when issuing ATSD invalidates

There are two types of ATSDs issued to the NPU: invalidates targeting a
specific virtual address and invalidates targeting the whole address
space. In both cases prior to this change, the sequence was:

    for each NPU
        - Write the target address to the XTS_ATSD_AVA register
        - EIEIO
        - Write the launch value to issue the ATSD

First, a target address is not required when invalidating the whole
address space, so that write and the EIEIO have been removed. The AP
(size) field in the launch is not needed either.

Second, for per-address invalidates the above sequence is inefficient in
the common case of multiple NPUs because an EIEIO is issued per NPU. This
unnecessarily forces the launches of later ATSDs to be ordered with the
launches of earlier ones. The new sequence only issues a single EIEIO:

    for each NPU
        - Write the target address to the XTS_ATSD_AVA register
    EIEIO
    for each NPU
        - Write the launch value to issue the ATSD

Performance results were gathered using a microbenchmark which creates a
1G allocation then uses mprotect with PROT_NONE to trigger invalidates in
strides across the allocation.

With only a single NPU active (one GPU) the difference is in the noise for
both types of invalidates (+/-1%).

With two NPUs active (on a 6-GPU system) the effect is more noticeable:

         mprotect rate (GB/s)
Stride   Before      After      Speedup
64K         5.9        6.5          10%
1M         31.2       33.4           7%
2M         36.3       38.7           7%
4M        322.6      356.7          11%

Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
6 years agopowerpc: remove leftover code of old GCC version checks
Masahiro Yamada [Mon, 1 Oct 2018 06:10:24 +0000 (15:10 +0900)]
powerpc: remove leftover code of old GCC version checks

Clean up the leftover of commit f2910f0e6835 ("powerpc: remove old
GCC version checks").

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>