Commit graph

752803 commits

Author SHA1 Message Date
Aneesh Kumar K.V 59879d542a powerpc/mm/book3s64: Move book3s64 code to pgtable-book3s64
Only code movement and avoid #ifdef.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15 22:29:09 +10:00
Michael Ellerman a42ae34f71 Merge branch 'topic/ppc-kvm' into next
This brings in one commit that we may want to share with the kvm-ppc
tree, to avoid merge conflicts and get wider testing.
2018-05-15 22:28:19 +10:00
Aneesh Kumar K.V 21828c99ee powerpc/kvm: Switch kvm pmd allocator to custom allocator
In the next set of patches, we will switch pmd allocator to use page fragments
and the locking will be updated to split pmd ptlock. We want to avoid using
fragments for partition-scoped table. Use slab cache similar to level 4 table

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15 22:27:06 +10:00
Souptick Joarder e807f02c5c powerpc/cell/spufs: Change return type to vm_fault_t
Use new return type vm_fault_t for fault handler. For now, this is
just documenting that the function returns a VM_FAULT value rather
than an errno. Once all instances are converted, vm_fault_t will
become a distinct type. See commit 1c8f422059 ("mm: change return
type to vm_fault_t").

We are fixing a minor bug, that the error from vm_insert_pfn() was
being ignored and the effect of this is likely to be only felt in OOM
situations.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-14 23:10:34 +10:00
Colin Ian King 942cc40ae4 macintosh/windfarm: fix spelling mistake: "ttarged" -> "ttarget"
Trivial fix to spelling mistake in debug messages of a structure
field name

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-14 23:10:33 +10:00
Nicholas Piggin c906d2c74e selftests/powerpc: fix exec benchmark
The exec_target binary could segfault calling _exit(2) because r13
is not set up properly (and libc looks at that when performing a
syscall). Call SYS_exit using syscall(2) which doesn't seem to
have this problem.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-14 23:10:33 +10:00
Alexey Kardashevskiy 7ef73cd39b powerpc/ioda: Use ibm, supported-tce-sizes for IOMMU page size mask
At the moment we assume that IODA2 and newer PHBs can always do 4K/64K/16M
IOMMU pages, however this is not the case for POWER9 and now skiboot
advertises the supported sizes via the device so we use that instead
of hard coding the mask.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-14 23:10:33 +10:00
Michael Ellerman 8ccb442dec powerpc/powernv: Fix memtrace build when NUMA=n
Currently memtrace doesn't build if NUMA=n:

  In function ‘memtrace_alloc_node’:
  arch/powerpc/platforms/powernv/memtrace.c:134:6:
  error: the address of ‘contig_page_data’ will always evaluate as ‘true’
    if (!NODE_DATA(nid) || !node_spanned_pages(nid))
        ^

This is because for NUMA=n NODE_DATA(nid) points to an always
allocated structure, contig_page_data.

But even in the NUMA=y case memtrace_alloc_node() is only called for
online nodes, and we should always have a NODE_DATA() allocated for an
online node. So remove the (hopefully) overly paranoid check, which
also means we can build when NUMA=n.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-14 19:25:43 +10:00
Michael Ellerman 89c1906272 powerpc/prom: Drop support for old FDT versions
In commit e6a6928c3e ("of/fdt: Convert FDT functions to use
libfdt") (Apr 2014), the generic flat device tree code dropped support
for flat device tree's older than version 0x10 (16).

We still have code in our CPU scanning to cope with flat device tree
versions earlier than 2, which can now never trigger, so drop it.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-11 23:29:04 +10:00
Michael Ellerman 6158faed7c powerpc/lib: Add alt patching test of branching past the last instruction
Add a test of the relative branch patching logic in the alternate
section feature fixup code. This tests that if we branch past the last
instruction of the alternate section, the branch is not patched.
That's because the assembler will have created a branch that already
points to the first instruction after the patched section, which is
correct and needs no further patching.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-11 23:29:03 +10:00
Michael Ellerman b58e798796 powerpc/lib: Rename ftr_fixup_test7 to ftr_fixup_test_too_big
We want this to remain the last test (because it's disabled by
default), so give it a non-numbered name so we don't have to renumber
it when adding new tests before it.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-11 23:29:03 +10:00
Michael Ellerman cad0e39023 powerpc/lib: Fix the feature fixup tests to actually work
The code patching code has always been a bit confused about whether
it's best to use void *, unsigned int *, char *, etc. to point to
instructions. In fact in the feature fixups tests we use both unsigned
int[] and u8[] in different places.

Unfortunately the tests that use unsigned int[] calculate the size of
the code blocks using subtraction of those unsigned int pointers, and
then pass the result to memcmp(). This means we're only comparing 1/4
of the bytes we need to, because we need to multiply by
sizeof(unsigned int) to get the number of *bytes*.

The result is that the tests do all the patching and then only compare
some of the resulting code, so patching bugs that only effect that
last 3/4 of the code could slip through undetected. It turns out that
hasn't been happening, although one test had a bad expected case (see
previous commit).

Fix it for now by multiplying the size by 4 in the affected functions.

Fixes: 362e7701fd ("powerpc: Add self-tests of the feature fixup code")
Epic-brown-paper-bag-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-11 23:29:02 +10:00
Michael Ellerman 32810d9132 powerpc/lib: Fix feature fixup test of external branch
The expected case for this test was wrong, the source of the alternate
code sequence is:

  FTR_SECTION_ELSE
  2:	or	2,2,2
  	PPC_LCMPI	r3,1
  	beq	3f
  	blt	2b
  	b	3f
  	b	1b
  ALT_FTR_SECTION_END(0, 1)
  3:	or	1,1,1
  	or	2,2,2
  4:	or	3,3,3

So when it's patched the '3' label should still be on the 'or 1,1,1',
and the 4 label is irrelevant and can be removed.

Fixes: 362e7701fd ("powerpc: Add self-tests of the feature fixup code")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-11 23:29:02 +10:00
Michael Ellerman 53da14d083 powerpc: Make it clearer that systbl check errors are errors
If the systbl_chk.sh checks fail we print a message, but with no
indication that it's an error. That makes it hard to find in build
logs with eg. grep.

So prefix any output with "Error:".

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:16 +10:00
Al Viro 4c1481ae60 powerpc/syscalls: timer_create can be handle by perfectly normal COMPAT_SYS_SPU
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:16 +10:00
Al Viro 28b9c34aa6 powerpc/syscalls: kill ppc32_select()
it had always been pointless - compat_sys_select() sign-extends
the first argument just fine on its own.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[mpe: Use COMPAT_SPU_NEW() to keep systbl_chk.sh happy]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:15 +10:00
Michael Ellerman 454d7ef81a powerpc/syscalls: Add COMPAT_SPU_NEW() macro
Currently the select system call is wired up with the SYSX_SPU()
macro. The SYSX_SPU() is not handled by systbl_chk.c, which means the
syscall number for select is not checked.

That hides the fact that the syscall number for select is actually
__NR__newselect not __NR_select.

In a following patch we'd like to drop ppc32_select() which means
select will become a regular COMPAT_SYS_SPU() syscall. But
COMPAT_SYS_SPU() can't deal with the fact that the syscall number is
actually __NR__newselect. We also can't just redefine __NR_select
because that's still used for the old select call.

So add a new COMPAT_NEW_SPU() that does the same thing as
COMPAT_SYS_SPU() except it encodes that we're using the new number.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:14 +10:00
Al Viro 4c392e6591 powerpc/syscalls: switch rtas(2) to SYSCALL_DEFINE
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[mpe: Update sys_ni.c for s/ppc_rtas/sys_rtas/]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:14 +10:00
Al Viro f3675644e1 powerpc/syscalls: signal_{32, 64} - switch to SYSCALL_DEFINE
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[mpe: Fix sys_debug_setcontext() prototype to return long]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:13 +10:00
Al Viro 3691d61455 powerpc/syscalls: Switch trivial cases to SYSCALL_DEFINE
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:12 +10:00
Torsten Duwe df78d3f614 powerpc/livepatch: Implement reliable stack tracing for the consistency model
The "Power Architecture 64-Bit ELF V2 ABI" says in section 2.3.2.3:

[...] There are several rules that must be adhered to in order to ensure
reliable and consistent call chain backtracing:

* Before a function calls any other function, it shall establish its
  own stack frame, whose size shall be a multiple of 16 bytes.

 – In instances where a function’s prologue creates a stack frame, the
   back-chain word of the stack frame shall be updated atomically with
   the value of the stack pointer (r1) when a back chain is implemented.
   (This must be supported as default by all ELF V2 ABI-compliant
   environments.)
[...]
 – The function shall save the link register that contains its return
   address in the LR save doubleword of its caller’s stack frame before
   calling another function.

To me this sounds like the equivalent of HAVE_RELIABLE_STACKTRACE.
This patch may be unneccessarily limited to ppc64le, but OTOH the only
user of this flag so far is livepatching, which is only implemented on
PPCs with 64-LE, a.k.a. ELF ABI v2.

Feel free to add other ppc variants, but so far only ppc64le got tested.

This change also implements save_stack_trace_tsk_reliable() for ppc64le
that checks for the above conditions, where possible.

Signed-off-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Nicolai Stange <nstange@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:12 +10:00
Nicholas Piggin 4e49226ea8 powerpc/watchdog: provide more data in watchdog messages
Provide timebase and timebase of last heartbeat in watchdog lockup
messages. Also provide a stack trace of when a CPU becomes un-stuck,
which can be useful -- it could be where irqs are re-enabled, so it
may be the end of the critical section which is responsible for the
latency which is useful information.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:11 +10:00
Nicholas Piggin 5a951c4e7e powerpc/watchdog: don't update the watchdog timestamp if a lockup is detected
The watchdog heartbeat timestamp is updated when the local heartbeat
timer fires (or touch_nmi_watchdog() is called).

This is an interesting data point, so don't overwrite it when the
soft-NMI interrupt detects a hard lockup. That code came from a pre-
merge version to prevent hard lockup messages flood, but that's taken
care of with the stuck CPU logic now, so there is no reason to
update the heartbeat timestamp here.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:11 +10:00
Cédric Le Goater 282498d65f powerpc/xive: prepare all hcalls to support long busy delays
This is not the case for the moment, but future releases of pHyp might
need to introduce some synchronisation routines under the hood which
would make the XIVE hcalls longer to complete.

As this was done for H_INT_RESET, let's wrap the other hcalls in a
loop catching the H_LONG_BUSY_* codes.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:10 +10:00
Cédric Le Goater 72224846fb powerpc/xive: shutdown XIVE when kexec or kdump is performed
The hcall H_INT_RESET should be called to make sure XIVE is fully
reseted.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:09 +10:00
Cédric Le Goater 028555a590 powerpc/xive: fix hcall H_INT_RESET to support long busy delays
The hcall H_INT_RESET can take some time to complete and in such cases
it returns H_LONG_BUSY_* codes requiring the machine to sleep for a
while before retrying.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:09 +10:00
Cédric Le Goater d2b04b0c78 powerpc/64/kexec: fix race in kexec when XIVE is shutdown
The kexec_state KEXEC_STATE_IRQS_OFF barrier is reached by all
secondary CPUs before the kexec_cpu_down() operation is called on
secondaries. This can raise conflicts and provoque errors in the XIVE
hcalls when XIVE is shutdown with H_INT_RESET on the primary CPU.

To synchronize the kexec_cpu_down() operations and make sure the
secondaries have completed their task before the primary starts doing
the same, let's move the primary kexec_cpu_down() after the
KEXEC_STATE_REAL_MODE barrier.

This change of the ending sequence of kexec is mostly useful on the
pseries platform but it impacts also the powernv, ps3 and 85xx
platforms. powernv can be easily tested and fixed but some caution is
required for the other two.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:08 +10:00
Nicholas Piggin 9a018fb1e1 powerpc/config: powernv_defconfig updates
For consideration:

* Add NVDIMM support - Enables greater testing, mambo device.
* Add IPv6 support built in + additional modules - Because it's 2018 maan.
* Add DEFERRED_STRUCT_PAGE_INIT - Let's see what breaks.
* Add PPC_MEMTRACE - Small powernv debugfs driver for getting hardware traces.
* Add MEMORY_FAILURE - Machine check exceptions can now drive memory failure.
* Turn on FANOTIFY - This is the current filesystem notification feature.
* Turn on SCOM_DEBUGFS - Handy for hardware/firmware debugging, security risk?
* Turn on async SCSI scanning - Let's see what breaks.
* Add MLX5 driver as a module - Popular demand.
* Add CRYPTO_CRCT10DIF_VPMSUM - POWER8 T10DIF acceleration.

* Make a bunch of USB hid drivers modules.
* Make SCSI SG, SR, and FC modules - FC is huge.
* Make video drivers except AST GPU modules - Also huge.
* Make PCI serial driver a module - Uncommon.
* Make more things modules, NFS FS, RAM disk, netconsole, MS-DOS fs.

* Get rid of /dev/port - Not used.
* Remove PPS and PTP subsystms - Unusual.
* Remove legacy BSD ttys - Long dead.
* Remove IDE - Deprecated and replaced with ATA.
* Remove WIRELESS - Until we get POWER9 laptops.
* Remove RAW - Long deprecated in favour of direct IO.
* Remove floppy, parport, and PS2 input devices - not supported.
* Remove virtio drivers, ballooning - We're host only.
* Remove PPP - Sorry Paulus.

This results in a significantly smaller vmlinux:

    text      data       bss        dec   filename
13143383   5277944   1317856   19739183   vanilla
12263281   4852074   1341720   18457075   patched

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:07 +10:00
Jonathan Neuschäfer c4c19684fa powerpc: wii_defconfig: Disable BCMA support
The B43 driver only needs CONFIG_SSB to support the WLAN card found in
the Wii. Configure it accordingly, and disable BCMA bus support to save
a bit of space.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:07 +10:00
Jonathan Neuschäfer 1a6d51f499 powerpc: wii_defconfig: Enable Wii SDHCI driver
This allows access to the SD card and the BCM4318 Wifi module.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:06 +10:00
Jonathan Neuschäfer d75f98dd24 powerpc: wii_defconfig: Enable GPIO-related options
Now that there's a GPIO driver for the Wii, let's enable the following
drivers:

- the GPIO driver itself
- gpio-keys
- gpio-poweroff
- gpio-leds and a few LED triggers

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:06 +10:00
Jonathan Neuschäfer a84813f5bf powerpc: wii_defconfig: Disable Ethernet driver support code
The Wii doesn't have built-in Ethernet and USB Ethernet adapters are in
a different menu. Disable CONFIG_ETHERNET to save some space in support
code for Ethernet drivers.

Note that this patch doesn't disable any Ethernet drivers, because they
are not enabled by default.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:05 +10:00
Wolfram Sang 7c18659dd4 powerpc/watchdog: fix typo 'can by' to 'can be'
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:05 +10:00
Michael Ellerman 8f2133cc0e powerpc/pseries: hcall_exit tracepoint retval should be signed
The hcall_exit() tracepoint has retval defined as unsigned long. That
leads to humours results like:

  bash-3686  [009] d..2   854.134094: hcall_entry: opcode=24
  bash-3686  [009] d..2   854.134095: hcall_exit: opcode=24 retval=18446744073709551609

It's normal for some hcalls to return negative values, displaying them
as unsigned isn't very helpful. So change it to signed.

  bash-3711  [001] d..2   471.691008: hcall_entry: opcode=24
  bash-3711  [001] d..2   471.691008: hcall_exit: opcode=24 retval=-7

Which can be more easily compared to H_NOT_FOUND in hvcall.h

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
2018-05-10 23:17:43 +10:00
Balbir Singh 7acf50e4ef Revert "powerpc/powernv: Increase memory block size to 1GB on radix"
This commit was a stop-gap to prevent crashes on hotunplug, caused by
the mismatch between the 1G mappings used for the linear mapping and the
memory block size. Those issues are now resolved because we split the
linear mapping at hotunplug time if necessary, as implemented in commit
4dd5f8a99e ("powerpc/mm/radix: Split linear mapping on hot-unplug").

Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Tested-by: Rashmica Gupta <rashmica.g@gmail.com>
Tested-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-07 21:22:02 +10:00
Christophe Leroy d5808ffaec powerpc/nohash: Use IS_ENABLED() to simplify __set_pte_at()
By using IS_ENABLED() we can simplify __set_pte_at() by removing
redundant *ptep = pte.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-07 20:37:47 +10:00
Christophe Leroy 0d594aa75f powerpc/nohash: Remove _PAGE_BUSY
_PAGE_BUSY is always 0, remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-07 20:37:46 +10:00
Christophe Leroy 45201c8794 powerpc/nohash: Remove hash related code from nohash headers.
When nohash and book3s header were split, some hash related stuff
remained in the nohash header. This patch removes them.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Duplicate pte_young() to avoid circular header dependency]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-07 20:37:46 +10:00
Mahesh Salgaonkar 722cde76d6 powerpc/fadump: Unregister fadump on kexec down path.
Unregister fadump on kexec down path otherwise the fadump registration
in new kexec-ed kernel complains that fadump is already registered.
This makes new kernel to continue using fadump registered by previous
kernel which may lead to invalid vmcore generation. Hence this patch
fixes this issue by un-registering fadump in fadump_cleanup() which is
called during kexec path so that new kernel can register fadump with
new valid values.

Fixes: b500afff11 ("fadump: Invalidate registration and release reserved memory for general use.")
Cc: stable@vger.kernel.org # v3.4+
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 23:19:30 +10:00
Hari Bathini 8597538712 powerpc/fadump: Do not use hugepages when fadump is active
FADump capture kernel boots in restricted memory environment preserving
the context of previous kernel to save vmcore. Supporting hugepages in
such environment makes things unnecessarily complicated, as hugepages
need memory set aside for them. This means most of the capture kernel's
memory is used in supporting hugepages. In most cases, this results in
out-of-memory issues while booting FADump capture kernel. But hugepages
are not of much use in capture kernel whose only job is to save vmcore.
So, disabling hugepages support, when fadump is active, is a reliable
solution for the out of memory issues. Introducing a flag variable to
disable HugeTLB support when fadump is active.

Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 23:09:25 +10:00
Mahesh Salgaonkar b71a693d3d powerpc/fadump: exclude memory holes while reserving memory in second kernel
The second kernel, during early boot after the crash, reserves rest of
the memory above boot memory size to make sure it does not touch any of the
dump memory area. It uses memblock_reserve() that reserves the specified
memory region irrespective of memory holes present within that region.
There are chances where previous kernel would have hot removed some of
its memory leaving memory holes behind. In such cases fadump kernel reports
incorrect number of reserved pages through arch_reserved_kernel_pages()
hook causing kernel to hang or panic.

Fix this by excluding memory holes while reserving rest of the memory
above boot memory size during second kernel boot after crash.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 23:09:24 +10:00
Michael Ellerman 0ea5ee0351 tracing: Remove PPC32 wart from config TRACING_SUPPORT
config TRACING_SUPPORT has an exception for PPC32, because PPC32
didn't have irqflags tracing support.

But that hasn't been true since commit 5d38902c48 ("powerpc: Add
irqtrace support for 32-bit powerpc") (Jun 2009).

So remove the exception for PPC32 and the comment.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 23:08:29 +10:00
Paul Gortmaker 3bc6cf5a86 powerpc: remove retired sbc834x support
I no longer have a functional version of this board for even the most
basic sanity boot testing, and they have not been available for purchase
for quite some years now.

There is no point in adding a burden to testing coverage that does
walk all the possible defconfigs, so with all the above in mind, it
makes sense to remove it.  Of course it will remain in the git history
for anyone who happens to stumble on one and wants to tinker with it.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:30 +10:00
Michael Ellerman 0c0c52306f powerpc: Only support DYNAMIC_FTRACE not static
We've had dynamic ftrace support for over 9 years since Steve first
wrote it, all the distros use dynamic, and static is basically
untested these days, so drop support for static ftrace.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:29 +10:00
Naveen N. Rao ae30cc05be powerpc64/ftrace: Implement support for ftrace_regs_caller()
With -mprofile-kernel, we always save the full register state in
ftrace_caller(). While this works, this is inefficient if we're not
interested in the register state, such as when we're using the function
tracer.

Rename the existing ftrace_caller() as ftrace_regs_caller() and provide
a simpler implementation for ftrace_caller() that is used when registers
are not required to be saved.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:29 +10:00
Naveen N. Rao 9ef4042364 powerpc64/ftrace: Use the generic version of ftrace_replace_code()
Our implementation matches that of the generic version, which also
handles FTRACE_UPDATE_MODIFY_CALL. So, remove our implementation in
favor of the generic version.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:28 +10:00
Naveen N. Rao 250122baed powerpc64/module: Tighten detection of mcount call sites with -mprofile-kernel
For R_PPC64_REL24 relocations, we suppress emitting instructions for TOC
load/restore in the relocation stub if the relocation is for _mcount()
call when using -mprofile-kernel ABI.

To detect this, we check if the preceding instructions are per the
standard set of instructions emitted by gcc: either the two instruction
sequence of 'mflr r0; std r0,16(r1)', or the more optimized variant of a
single 'mflr r0'. This is not sufficient since nothing prevents users
from hand coding sequences involving a 'mflr r0' followed by a 'bl'.

For removing the toc save instruction from the stub, we additionally
check if the symbol is "_mcount". Add the same check here as well.

Also rename is_early_mcount_callsite() to is_mprofile_mcount_callsite()
since that is what is being checked. The use of "early" is misleading
since there is nothing involving this function that qualifies as early.

Fixes: 153086644f ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:28 +10:00
Naveen N. Rao 88b1a8547f powerpc64/kexec: Hard disable ftrace before switching to the new kernel
If function_graph tracer is enabled during kexec, we see the below
exception in the simulator:
	root@(none):/# kexec -e
	kvm: exiting hardware virtualization
	kexec_core: Starting new kernel
	[   19.262020070,5] OPAL: Switch to big-endian OS
	kexec: Starting switchover sequence.
	Interrupt to 0xC000000000004380 from 0xC000000000004380
	** Execution stopped: Continuous Interrupt, Instruction caused exception,  **

Now that we have a more effective way to completely disable ftrace on
ppc64, let's also use that before switching to a new kernel during
kexec.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:27 +10:00
Naveen N. Rao a4bc64d305 powerpc64/ftrace: Disable ftrace during kvm entry/exit
During guest entry/exit, we switch over to/from the guest MMU context
and we cannot take exceptions in the hypervisor code.

Since ftrace may be enabled and since it can result in us taking a trap,
disable ftrace by setting paca->ftrace_enabled to zero. There are two
paths through which we enter/exit a guest:
1. If we are the vcore runner, then we enter the guest via
__kvmppc_vcore_entry() and we disable ftrace around this. This is always
the case for Power9, and for the primary thread on Power8.
2. If we are a secondary thread in Power8, then we would be in nap due
to SMT being disabled. We are woken up by an IPI to enter the guest. In
this scenario, we enter the guest through kvm_start_guest(). We disable
ftrace at this point. In this scenario, ftrace would only get re-enabled
on the secondary thread when SMT is re-enabled (via start_secondary()).

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:27 +10:00
Naveen N. Rao 424ef0160f powerpc64/ftrace: Disable ftrace during hotplug
Disable ftrace when a cpu is about to go offline. When the cpu is woken
up, ftrace will get enabled in start_secondary().

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:27 +10:00