Commit Graph

6395 Commits

Author SHA1 Message Date
Firoz Khan
ab66dcc76d powerpc: generate uapi header and system call table files
System call table generation script must be run to gener-
ate unistd_32/64.h and syscall_table_32/64/c32/spu.h files.
This patch will have changes which will invokes the script.

This patch will generate unistd_32/64.h and syscall_table-
_32/64/c32/spu.h files by the syscall table generation
script invoked by parisc/Makefile and the generated files
against the removed files must be identical.

The generated uapi header file will be included in uapi/-
asm/unistd.h and generated system call table header file
will be included by kernel/systbl.S file.

Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 14:46:50 +11:00
Firoz Khan
aff8503932 powerpc: add system call table generation support
The system call tables are in different format in all
architecture and it will be difficult to manually add or
modify the system calls in the respective files. To make
it easy by keeping a script and which will generate the
uapi header and syscall table file. This change will also
help to unify the implementation across all architectures.

The system call table generation script is added in
syscalls directory which contain the script to generate
both uapi header file and system call table files.
The syscall.tbl file will be the input for the scripts.

syscall.tbl contains the list of available system calls
along with system call number and corresponding entry point.
Add a new system call in this architecture will be possible
by adding new entry in the syscall.tbl file.

Adding a new table entry consisting of:
  	- System call number.
	- ABI.
	- System call name.
	- Entry point name.
	- Compat entry name, if required.

syscallhdr.sh and syscalltbl.sh will generate uapi header-
unistd_32/64.h and syscall_table_32/64/c32/spu.h files
respectively. File syscall_table_32/64/c32/spu.h is incl-
uded by syscall.S - the real system call table. Both *.sh
files will parse the content syscall.tbl to generate the
header and table files.

ARM, s390 and x86 architecuture does have similar support.
I leverage their implementation to come up with a generic
solution.

Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 14:46:50 +11:00
Firoz Khan
fbf508da74 powerpc: split compat syscall table out from native table
PowerPC uses a syscall table with native and compat calls
interleaved, which is a slightly simpler way to define two
matching tables.

As we move to having the tables generated, that advantage
is no longer important, but the interleaved table gets in
the way of using the same scripts as on the other archit-
ectures.

Split out a new compat_sys_call_table symbol that contains
all the compat calls, and leave the main table for the nat-
ive calls, to more closely match the method we use every-
where else.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 14:46:50 +11:00
Firoz Khan
a11b763d61 powerpc: move macro definition from asm/systbl.h
Move the macro definition for compat_sys_sigsuspend from
asm/systbl.h to the file which it is getting included.

One of the patch in this patch series is generating uapi
header and syscall table files. In order to come up with
a common implimentation across all architecture, we need
to do this change.

This change will simplify the implementation of system
call table generation script and help to come up a common
implementation across all architecture.

Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 14:46:50 +11:00
Breno Leitao
6f5b9f018f powerpc/tm: Unset MSR[TS] if not recheckpointing
There is a TM Bad Thing bug that can be caused when you return from a
signal context in a suspended transaction but with ucontext MSR[TS] unset.

This forces regs->msr[TS] to be set at syscall entrance (since the CPU
state is transactional). It also calls treclaim() to flush the transaction
state, which is done based on the live (mfmsr) MSR state.

Since user context MSR[TS] is not set, then restore_tm_sigcontexts() is not
called, thus, not executing recheckpoint, keeping the CPU state as not
transactional. When calling rfid, SRR1 will have MSR[TS] set, but the CPU
state is non transactional, causing the TM Bad Thing with the following
stack:

	[   33.862316] Bad kernel stack pointer 3fffd9dce3e0 at c00000000000c47c
	cpu 0x8: Vector: 700 (Program Check) at [c00000003ff7fd40]
	    pc: c00000000000c47c: fast_exception_return+0xac/0xb4
	    lr: 00003fff865f442c
	    sp: 3fffd9dce3e0
	   msr: 8000000102a03031
	  current = 0xc00000041f68b700
	  paca    = 0xc00000000fb84800   softe: 0        irq_happened: 0x01
	    pid   = 1721, comm = tm-signal-sigre
	Linux version 4.9.0-3-powerpc64le (debian-kernel@lists.debian.org) (gcc version 6.3.0 20170516 (Debian 6.3.0-18) ) #1 SMP Debian 4.9.30-2+deb9u2 (2017-06-26)
	WARNING: exception is not recoverable, can't continue

The same problem happens on 32-bits signal handler, and the fix is very
similar, if tm_recheckpoint() is not executed, then regs->msr[TS] should be
zeroed.

This patch also fixes a sparse warning related to lack of indentation when
CONFIG_PPC_TRANSACTIONAL_MEM is set.

Fixes: 2b0a576d15 ("powerpc: Add new transactional memory state to the signal context")
CC: Stable <stable@vger.kernel.org>	# 3.10+
Signed-off-by: Breno Leitao <leitao@debian.org>
Tested-by: Michal Suchánek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 14:46:50 +11:00
Breno Leitao
11be39584a powerpc/tm: Print scratch value
Usually a TM Bad Thing exception is raised due to three different problems.
a) touching SPRs in an active transaction; b) using TM instruction with the
facility disabled and c) setting a wrong MSR/SRR1 at RFID.

The two initial cases are easy to identify by looking at the instructions.
The latter case is harder, because the MSR is masked after RFID, so, it is
very useful to look at the previous MSR (SRR1) before RFID as also the
current and masked MSR.

Since MSR is saved at paca just before RFID, this patch prints it if a TM
Bad thing happen, helping to understand what is the invalid TM transition
that is causing the exception.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 14:46:50 +11:00
Breno Leitao
63a0d6b03b powerpc/tm: Save MSR to PACA before RFID
As other exit points, move SRR1 (MSR) into paca->tm_scratch, so, if
there is a TM Bad Thing in RFID, it is easy to understand what was the
SRR1 value being used.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 14:46:50 +11:00
Breno Leitao
e1c3743e1a powerpc/tm: Set MSR[TS] just prior to recheckpoint
On a signal handler return, the user could set a context with MSR[TS] bits
set, and these bits would be copied to task regs->msr.

At restore_tm_sigcontexts(), after current task regs->msr[TS] bits are set,
several __get_user() are called and then a recheckpoint is executed.

This is a problem since a page fault (in kernel space) could happen when
calling __get_user(). If it happens, the process MSR[TS] bits were
already set, but recheckpoint was not executed, and SPRs are still invalid.

The page fault can cause the current process to be de-scheduled, with
MSR[TS] active and without tm_recheckpoint() being called.  More
importantly, without TEXASR[FS] bit set also.

Since TEXASR might not have the FS bit set, and when the process is
scheduled back, it will try to reclaim, which will be aborted because of
the CPU is not in the suspended state, and, then, recheckpoint. This
recheckpoint will restore thread->texasr into TEXASR SPR, which might be
zero, hitting a BUG_ON().

	kernel BUG at /build/linux-sf3Co9/linux-4.9.30/arch/powerpc/kernel/tm.S:434!
	cpu 0xb: Vector: 700 (Program Check) at [c00000041f1576d0]
	    pc: c000000000054550: restore_gprs+0xb0/0x180
	    lr: 0000000000000000
	    sp: c00000041f157950
	   msr: 8000000100021033
	  current = 0xc00000041f143000
	  paca    = 0xc00000000fb86300	 softe: 0	 irq_happened: 0x01
	    pid   = 1021, comm = kworker/11:1
	kernel BUG at /build/linux-sf3Co9/linux-4.9.30/arch/powerpc/kernel/tm.S:434!
	Linux version 4.9.0-3-powerpc64le (debian-kernel@lists.debian.org) (gcc version 6.3.0 20170516 (Debian 6.3.0-18) ) #1 SMP Debian 4.9.30-2+deb9u2 (2017-06-26)
	enter ? for help
	[c00000041f157b30] c00000000001bc3c tm_recheckpoint.part.11+0x6c/0xa0
	[c00000041f157b70] c00000000001d184 __switch_to+0x1e4/0x4c0
	[c00000041f157bd0] c00000000082eeb8 __schedule+0x2f8/0x990
	[c00000041f157cb0] c00000000082f598 schedule+0x48/0xc0
	[c00000041f157ce0] c0000000000f0d28 worker_thread+0x148/0x610
	[c00000041f157d80] c0000000000f96b0 kthread+0x120/0x140
	[c00000041f157e30] c00000000000c0e0 ret_from_kernel_thread+0x5c/0x7c

This patch simply delays the MSR[TS] set, so, if there is any page fault in
the __get_user() section, it does not have regs->msr[TS] set, since the TM
structures are still invalid, thus avoiding doing TM operations for
in-kernel exceptions and possible process reschedule.

With this patch, the MSR[TS] will only be set just before recheckpointing
and setting TEXASR[FS] = 1, thus avoiding an interrupt with TM registers in
invalid state.

Other than that, if CONFIG_PREEMPT is set, there might be a preemption just
after setting MSR[TS] and before tm_recheckpoint(), thus, this block must
be atomic from a preemption perspective, thus, calling
preempt_disable/enable() on this code.

It is not possible to move tm_recheckpoint to happen earlier, because it is
required to get the checkpointed registers from userspace, with
__get_user(), thus, the only way to avoid this undesired behavior is
delaying the MSR[TS] set.

The 32-bits signal handler seems to be safe this current issue, but, it
might be exposed to the preemption issue, thus, disabling preemption in
this chunk of code.

Changes from v2:
 * Run the critical section with preempt_disable.

Fixes: 87b4e5393a ("powerpc/tm: Fix return of active 64bit signals")
Cc: stable@vger.kernel.org (v3.9+)
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 14:46:50 +11:00
Mahesh Salgaonkar
0db6896ff6 powerpc/fadump: Do not allow hot-remove memory from fadump reserved area.
For fadump to work successfully there should not be any holes in reserved
memory ranges where kernel has asked firmware to move the content of old
kernel memory in event of crash. Now that fadump uses CMA for reserved
area, this memory area is now not protected from hot-remove operations
unless it is cma allocated. Hence, fadump service can fail to re-register
after the hot-remove operation, if hot-removed memory belongs to fadump
reserved region. To avoid this make sure that memory from fadump reserved
area is not hot-removable if fadump is registered.

However, if user still wants to remove that memory, he can do so by
manually stopping fadump service before hot-remove operation.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Mahesh Salgaonkar
f86593be1e powerpc/fadump: Throw proper error message on fadump registration failure
fadump fails to register when there are holes in reserved memory area.
This can happen if user has hot-removed a memory that falls in the
fadump reserved memory area. Throw a meaningful error message to the
user in such case.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
[mpe: is_reserved_memory_area_contiguous() returns bool, unsplit string]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
Mahesh Salgaonkar
a4e92ce8e4 powerpc/fadump: Reservationless firmware assisted dump
One of the primary issues with Firmware Assisted Dump (fadump) on Power
is that it needs a large amount of memory to be reserved. On large
systems with TeraBytes of memory, this reservation can be quite
significant.

In some cases, fadump fails if the memory reserved is insufficient, or
if the reserved memory was DLPAR hot-removed.

In the normal case, post reboot, the preserved memory is filtered to
extract only relevant areas of interest using the makedumpfile tool.
While the tool provides flexibility to determine what needs to be part
of the dump and what memory to filter out, all supported distributions
default this to "Capture only kernel data and nothing else".

We take advantage of this default and the Linux kernel's Contiguous
Memory Allocator (CMA) to fundamentally change the memory reservation
model for fadump.

Instead of setting aside a significant chunk of memory nobody can use,
this patch uses CMA instead, to reserve a significant chunk of memory
that the kernel is prevented from using (due to MIGRATE_CMA), but
applications are free to use it. With this fadump will still be able
to capture all of the kernel memory and most of the user space memory
except the user pages that were present in CMA region.

Essentially, on a P9 LPAR with 2 cores, 8GB RAM and current upstream:
[root@zzxx-yy10 ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:           7557         193        6822          12         541        6725
Swap:          4095           0        4095

With this patch:
[root@zzxx-yy10 ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:           8133         194        7464          12         475        7338
Swap:          4095           0        4095

Changes made here are completely transparent to how fadump has
traditionally worked.

Thanks to Aneesh Kumar and Anshuman Khandual for helping us understand
CMA and its usage.

TODO:
- Handle case where CMA reservation spans nodes.

Signed-off-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
YueHaibing
8c6c942d33 powerpc/eeh: Fix debugfs_simple_attr.cocci warnings
Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE
for debugfs files.

Semantic patch information:
Rationale: DEFINE_SIMPLE_ATTRIBUTE + debugfs_create_file()
imposes some significant overhead as compared to
DEFINE_DEBUGFS_ATTRIBUTE + debugfs_create_file_unsafe().

Generated by: scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
dfa88658fb powerpc/fsl: Update Spectre v2 reporting
Report branch predictor state flush as a mitigation for
Spectre variant 2.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
3bc8ea8603 powerpc/fsl: Enable runtime patching if nospectre_v2 boot arg is used
If the user choses not to use the mitigations, replace
the code sequence with nops.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
7fef436295 powerpc/fsl: Flush the branch predictor at each kernel entry (32 bit)
In order to protect against speculation attacks on
indirect branches, the branch predictor is flushed at
kernel entry to protect for the following situations:
- userspace process attacking another userspace process
- userspace process attacking the kernel
Basically when the privillege level change (i.e.the kernel
is entered), the branch predictor state is flushed.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
10c5e83afd powerpc/fsl: Flush the branch predictor at each kernel entry (64bit)
In order to protect against speculation attacks on
indirect branches, the branch predictor is flushed at
kernel entry to protect for the following situations:
- userspace process attacking another userspace process
- userspace process attacking the kernel
Basically when the privillege level change (i.e. the
kernel is entered), the branch predictor state is flushed.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
f633a8ad63 powerpc/fsl: Add nospectre_v2 command line argument
When the command line argument is present, the Spectre variant 2
mitigations are disabled.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
7d8bad99ba powerpc/fsl: Fix spectre_v2 mitigations reporting
Currently for CONFIG_PPC_FSL_BOOK3E the spectre_v2 file is incorrect:

  $ cat /sys/devices/system/cpu/vulnerabilities/spectre_v2
  "Mitigation: Software count cache flush"

Which is wrong. Fix it to report vulnerable for now.

Fixes: ee13cb249f ("powerpc/64s: Add support for software count cache flush")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Diana Craciun
76a5eaa38b powerpc/fsl: Add infrastructure to fixup branch predictor flush
In order to protect against speculation attacks (Spectre
variant 2) on NXP PowerPC platforms, the branch predictor
should be flushed when the privillege level is changed.
This patch is adding the infrastructure to fixup at runtime
the code sections that are performing the branch predictor flush
depending on a boot arg parameter which is added later in a
separate patch.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:53:39 +11:00
Christophe Leroy
f242e0ac95 powerpc/prom: move the device tree if not in declared memory.
If the device tree doesn't reside in the memory which is declared
inside it, it has to be moved as well as this memory will not be
mapped by the kernel.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Arnd Bergmann
2fea82db11 powerpc: eeh_event: convert semaphore to completion
For this use case, completions and semaphores are equivalent,
but semaphores are an awkward interface that should generally
be avoided, so use the completion instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Dmitry V. Levin
8dbdec0bcb powerpc/ptrace: Combine SYSCALL_EMU & SYSCALL_TRACE handling
Combine the SYSCALL_EMU and SYSCALL_TRACE handling so that we only
call tracehook_report_syscall_entry() in one place.

Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
[mpe: Flesh out change log, s/cached_flags/flags/, reflow comments]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Christoph Hellwig
25078dc1f7 powerpc: use mm zones more sensibly
Powerpc has somewhat odd usage where ZONE_DMA is used for all memory on
common 64-bit configfs, and ZONE_DMA32 is used for 31-bit schemes.

Move to a scheme closer to what other architectures use (and I dare to
say the intent of the system):

 - ZONE_DMA: optionally for memory < 31-bit (64-bit embedded only)
 - ZONE_NORMAL: everything addressable by the kernel
 - ZONE_HIGHMEM: memory > 32-bit for 32-bit kernels

Also provide information on how ZONE_DMA is used by defining
ARCH_ZONE_DMA_BITS.

Contains various fixes from Benjamin Herrenschmidt.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Christoph Hellwig
44a0337b32 powerpc/dma: split the two __dma_alloc_coherent implementations
The implemementation for the CONFIG_NOT_COHERENT_CACHE case doesn't share
any code with the one for systems with coherent caches.  Split it off
and merge it with the helpers in dma-noncoherent.c that have no other
callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Christoph Hellwig
9c15a87cfc powerpc/dma: remove the unused dma_iommu_ops export
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Christoph Hellwig
acddff9dc4 powerpc/dma: remove the unused ISA_DMA_THRESHOLD export
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Christoph Hellwig
0aeba2d0d2 powerpc/dma: properly wire up the unmap_page and unmap_sg methods
The unmap methods need to transfer memory ownership back from the
device to the cpu by identical means as dma_sync_*_to_cpu. I'm not
sure powerpc needs to do any work in this transfer direction, but
given that it does invalidate the caches in dma_sync_*_to_cpu already
we should make sure we also do so on unmapping.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[mpe: s/dir/direction in dma_nommu_unmap_page()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Christophe Leroy
b18f0ae92b powerpc/prom: fix early DEBUG messages
This patch fixes early DEBUG messages in prom.c:
- Use %px instead of %p to see the addresses
- Cast memblock_phys_mem_size() with (unsigned long long) to
avoid build failure when phys_addr_t is not 64 bits.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:21:20 +11:00
Christophe Leroy
385e89d5b2 powerpc/mm: add exec protection on powerpc 603
The 603 doesn't have a HASH table, TLB misses are handled by
software. It is then possible to generate page fault when
_PAGE_EXEC is not set like in nohash/32.

There is one "reserved" PTE bit available, this patch uses
it for _PAGE_EXEC.

In order to support it, set_pte_filter() and
set_access_flags_filter() are made common, and the handling
is made dependent on MMU_FTR_HPTE_TABLE

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-19 18:56:32 +11:00
Christophe Leroy
c62ce9ef97 powerpc: remove remaining bits from CONFIG_APUS
commit f21f49ea63 ("[POWERPC] Remove the dregs of APUS support from
arch/powerpc") removed CONFIG_APUS, but forgot to remove the logic
which adapts tophys() and tovirt() for it.

This patch removes the last stale pieces.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-19 18:56:32 +11:00
Christophe Leroy
0ed5b55884 powerpc/8xx: add exception frame marker
This patch adds STACK_FRAME_REGS_MARKER in the stack at exception entry
in order to see interrupts in call traces as below:

[    0.013964] Call Trace:
[    0.014014] [c0745db0] [c007a9d4] tick_periodic.constprop.5+0xd8/0x104 (unreliable)
[    0.014086] [c0745dc0] [c007aa20] tick_handle_periodic+0x20/0x9c
[    0.014181] [c0745de0] [c0009cd0] timer_interrupt+0xa0/0x264
[    0.014258] [c0745e10] [c000e484] ret_from_except+0x0/0x14
[    0.014390] --- interrupt: 901 at console_unlock.part.7+0x3f4/0x528
[    0.014390]     LR = console_unlock.part.7+0x3f0/0x528
[    0.014455] [c0745ee0] [c0050334] console_unlock.part.7+0x114/0x528 (unreliable)
[    0.014542] [c0745f30] [c00524e0] register_console+0x3d8/0x44c
[    0.014625] [c0745f60] [c0675aac] cpm_uart_console_init+0x18/0x2c
[    0.014709] [c0745f70] [c06614f4] console_init+0x114/0x1cc
[    0.014795] [c0745fb0] [c0658b68] start_kernel+0x300/0x3d8
[    0.014864] [c0745ff0] [c00022cc] start_here+0x44/0x98

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-19 18:56:32 +11:00
Christophe Leroy
6c16816b91 powerpc/44x: use patch_sites for TLB handlers patching
Use patch sites and associated helpers to manage TLB handlers
patching instead of hardcoding.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-19 18:56:32 +11:00
Christophe Leroy
d16952a629 powerpc/signal: Use code patching instead of hardcoding
Instead of hardcoding code modifications, use code patching functions.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-19 18:56:32 +11:00
Christophe Leroy
4a3a224c5a powerpc/book3s/32: Use MMU_FTR_HPTE_TABLE in head_32.S
Instead of manually patching a blr at hash_page() entry in
MMU_init_hw(), this patch adds a features section in head_32.S

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-19 18:56:32 +11:00
Christophe Leroy
04b0a72f28 powerpc/32: use patch_site_addr() in machine_init()
Use patch_site_addr() instead of hardcoding the
address calculation in machine_init()

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-19 18:56:32 +11:00
Michael Ellerman
4d6a198273 Merge branch 'fixes' into next
Merge our fixes branch again, this has a couple of build fixes and also
a change to do_syscall_trace_enter() that will conflict with a patch we
want to apply in next.
2018-12-17 22:11:54 +11:00
Elvira Khabirova
a225f15674 powerpc/ptrace: replace ptrace_report_syscall() with a tracehook call
Arch code should use tracehook_*() helpers, as documented in
include/linux/tracehook.h, ptrace_report_syscall() is not expected to
be used outside that file.

The patch does not look very nice, but at least it is correct
and opens the way for PTRACE_GET_SYSCALL_INFO API.

Co-authored-by: Dmitry V. Levin <ldv@altlinux.org>
Fixes: 5521eb4bca ("powerpc/ptrace: Add support for PTRACE_SYSEMU")
Signed-off-by: Elvira Khabirova <lineprinter@altlinux.org>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
[mpe: Take this as a minimal fix for 4.20, we'll rework it later]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-10 15:19:58 +11:00
Christophe Leroy
b14fc50266 powerpc/8xx: regroup TLB handler routines
As this is running with MMU off, the CPU only does speculative
fetch for code in the same page.

Following the significant size reduction of TLB handler routines,
the side handlers can be brought back close to the main part,
ie in the same page.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-04 19:45:01 +11:00
Christophe Leroy
74fabcadfd powerpc/8xx: don't use r12/SPRN_SPRG_SCRATCH2 in TLB Miss handlers
This patch reworks the TLB Miss handler in order to not use r12
register, hence avoiding having to save it into SPRN_SPRG_SCRATCH2.

In the DAR Fixup code we can now use SPRN_M_TW, freeing
SPRN_SPRG_SCRATCH2.

Then SPRN_SPRG_SCRATCH2 may be used for something else in the future.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-04 19:45:01 +11:00
Christophe Leroy
6a8f911b50 powerpc/8xx: Use hardware assistance in TLB handlers
Today, on the 8xx the TLB handlers do SW tablewalk by doing all
the calculation in ASM, in order to match with the Linux page
table structure.

The 8xx offers hardware assistance which allows significant size
reduction of the TLB handlers, hence also reduces the time spent
in the handlers.

However, using this HW assistance implies some constraints on the
page table structure:
- Regardless of the main page size used (4k or 16k), the
level 1 table (PGD) contains 1024 entries and each PGD entry covers
a 4Mbytes area which is managed by a level 2 table (PTE) containing
also 1024 entries each describing a 4k page.
- 16k pages require 4 identifical entries in the L2 table
- 512k pages PTE have to be spread every 128 bytes in the L2 table
- 8M pages PTE are at the address pointed by the L1 entry and each
8M page require 2 identical entries in the PGD.

This patch modifies the TLB handlers to use HW assistance for 4K PAGES.

Before that patch, the mean time spent in TLB miss handlers is:
- ITLB miss: 80 ticks
- DTLB miss: 62 ticks
After that patch, the mean time spent in TLB miss handlers is:
- ITLB miss: 72 ticks
- DTLB miss: 54 ticks
So the improvement is 10% for ITLB and 13% for DTLB misses

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-04 19:45:01 +11:00
Christophe Leroy
5af543be14 powerpc/8xx: Temporarily disable 16k pages and hugepages
In preparation of making use of hardware assistance in TLB handlers,
this patch temporarily disables 16K pages and hugepages. The reason
is that when using HW assistance in 4K pages mode, the linux model
fit with the HW model for 4K pages and 8M pages.

However for 16K pages and 512K mode some additional work is needed
to get linux model fit with HW model.
For the 8M pages, they will naturaly come back when we switch to
HW assistance, without any additional handling.
In order to keep the following patch smaller, the removal of the
current special handling for 8M pages gets removed here as well.

Therefore the 4K pages mode will be implemented first and without
support for 512k hugepages. Then the 512k hugepages will be brought
back. And the 16K pages will be implemented in the following step.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-04 19:45:01 +11:00
Christophe Leroy
8cfe4f5242 powerpc/8xx: Move SW perf counters in first 32kb of memory
In order to simplify time critical exceptions handling 8xx
specific SW perf counters, this patch moves the counters into
the beginning of memory. This is possible because .text is readable
and the counters are never modified outside of the handlers.

By doing this, we avoid having to set a second register with
the upper part of the address of the counters.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-04 19:45:01 +11:00
Christophe Leroy
994da93d19 powerpc/mm: move platform specific mmu-xxx.h in platform directories
The purpose of this patch is to move platform specific
mmu-xxx.h files in platform directories like pte-xxx.h files.

In the meantime this patch creates common nohash and
nohash/32 + nohash/64 mmu.h files for future common parts.

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>
2018-12-04 19:45:01 +11:00
Stephen Rothwell
8ad940217c powerpc: annotate implicit fall throughs
There is a plan to build the kernel with -Wimplicit-fallthrough and these
places in the code produced warnings, but because we build arch/powerpc
with -Werror, they became errors.  Fix them up.

This patch produces no change in behaviour, but should be reviewed in
case these are actually bugs not intentional fallthoughs.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-04 19:45:01 +11:00
Benjamin Herrenschmidt
bf3d6afbb2 powerpc: Look for "stdout-path" when setting up legacy consoles
Commit 78e5dfea84 ("powerpc: dts: replace 'linux,stdout-path' with
'stdout-path'") broke the default console on a number of embedded
PowerPC systems, because it failed to also update the code in
arch/powerpc/kernel/legacy_serial.c to look for that property in
addition to the old one.

This fixes it.

Fixes: 78e5dfea84 ("powerpc: dts: replace 'linux,stdout-path' with 'stdout-path'")
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-01 14:37:36 +11:00
Radu Rendec
78e7b15e17 powerpc/msi: Fix NULL pointer access in teardown code
The arch_teardown_msi_irqs() function assumes that controller ops
pointers were already checked in arch_setup_msi_irqs(), but this
assumption is wrong: arch_teardown_msi_irqs() can be called even when
arch_setup_msi_irqs() returns an error (-ENOSYS).

This can happen in the following scenario:
  - msi_capability_init() calls pci_msi_setup_msi_irqs()
  - pci_msi_setup_msi_irqs() returns -ENOSYS
  - msi_capability_init() notices the error and calls free_msi_irqs()
  - free_msi_irqs() calls pci_msi_teardown_msi_irqs()

This is easier to see when CONFIG_PCI_MSI_IRQ_DOMAIN is not set and
pci_msi_setup_msi_irqs() and pci_msi_teardown_msi_irqs() are just
aliases to arch_setup_msi_irqs() and arch_teardown_msi_irqs().

The call to free_msi_irqs() upon pci_msi_setup_msi_irqs() failure
seems legit, as it does additional cleanup; e.g.
list_del(&entry->list) and kfree(entry) inside free_msi_irqs() do
happen (MSI descriptors are allocated before pci_msi_setup_msi_irqs()
is called and need to be cleaned up if that fails).

Fixes: 6b2fd7efeb ("PCI/MSI/PPC: Remove arch_msi_check_device()")
Cc: stable@vger.kernel.org # v3.18+
Signed-off-by: Radu Rendec <radu.rendec@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-11-29 23:49:11 +11:00
Christophe Leroy
68289ae935 powerpc: change CONFIG_PPC_STD_MMU_32 to CONFIG_PPC_BOOK3S_32
Today we have:

config PPC_BOOK3S_32
        bool "512x/52xx/6xx/7xx/74xx/82xx/83xx/86xx"
        [depends on PPC32 within a choice]

config PPC_BOOK3S
        def_bool y
        depends on PPC_BOOK3S_32 || PPC_BOOK3S_64

config PPC_STD_MMU
	def_bool y
	depends on PPC_BOOK3S

config PPC_STD_MMU_32
	def_bool y
	depends on PPC_STD_MMU && PPC32

PPC_STD_MMU_32 is therefore redundant with PPC_BOOK3S_32.

In order to make the code clearer, lets use preferably PPC_BOOK3S_32.
This will allow to remove CONFIG_PPC_STD_MMU_32 in a later patch.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-11-26 22:33:37 +11:00
Christophe Leroy
d7cceda96b powerpc: change CONFIG_6xx to CONFIG_PPC_BOOK3S_32
Today we have:

config PPC_BOOK3S_32
	bool "512x/52xx/6xx/7xx/74xx/82xx/83xx/86xx"
	[depends on PPC32 within a choice]

config PPC_BOOK3S
	def_bool y
	depends on PPC_BOOK3S_32 || PPC_BOOK3S_64

config 6xx
	def_bool y
	depends on PPC32 && PPC_BOOK3S

6xx is therefore redundant with PPC_BOOK3S_32.

In order to make the code clearer, lets use preferably PPC_BOOK3S_32.
This will allow to remove CONFIG_6xx in a later patch.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-11-26 22:33:37 +11:00
Rob Herring
e5480bdcc4 powerpc: Use device_type helpers to access the node type
Remove directly accessing device_node.type pointer and use the
accessors instead. This will eventually allow removing the type
pointer.

Replace the open coded iterating over child nodes with
for_each_child_of_node() while we're here.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-11-26 22:33:37 +11:00
Rob Herring
5b8d6be7b8 powerpc: Rework btext_find_display to use of_stdout and device_type helpers
Remove directly accessing device_node.type pointer and use the
accessors instead. This will eventually allow removing the type
pointer.

In the process, the of_stdout pointer can be used instead of finding
the stdout node again.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-11-26 22:33:37 +11:00