Commit Graph

1247 Commits

Author SHA1 Message Date
Evgeniy Didin
099df531a4 ARC: [plat-hsdk]: Switch ethernet phy-mode to rgmii-id
[ Upstream commit 26907eb605 ]

HSDK board has Micrel KSZ9031, recent commit
bcf3440c6d ("net: phy: micrel: add phy-mode support for the KSZ9031 PHY")
caused a breakdown of Ethernet.
Using 'phy-mode = "rgmii"' is not correct because accodring RGMII
specification it is necessary to have delay on RX (PHY to MAX)
which is not generated in case of "rgmii".
Using "rgmii-id" adds necessary delay and solves the issue.

Also adding name of PHY placed on HSDK board.

Signed-off-by: Evgeniy Didin <Evgeniy.Didin@synopsys.com>
Cc: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-17 13:45:25 +02:00
Vineet Gupta
10d4f8d200 irqchip/eznps: Fix build error for !ARC700 builds
[ Upstream commit 89d29997f1 ]

eznps driver is supposed to be platform independent however it ends up
including stuff from inside arch/arc headers leading to rand config
build errors.

The quick hack to fix this (proper fix is too much chrun for non active
user-base) is to add following to nps platform agnostic header.
 - copy AUX_IENABLE from arch/arc header
 - move CTOP_AUX_IACK from arch/arc/plat-eznps/*/**

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lkml.kernel.org/r/20200824095831.5lpkmkafelnvlpi2@linutronix.de
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-17 13:45:25 +02:00
Vineet Gupta
281c6d2050 ARC: HSDK: wireup perf irq
[ Upstream commit fe81d927b7 ]

Newer version of HSDK aka HSDK-4xD (with dual issue HS48x4 CPU) wired up
the perf interrupt, so enable that in DT.
This is OK for old HSDK where this irq is ignored because pct irq is not
wired up in hardware.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-17 13:45:23 +02:00
Vineet Gupta
391a502e5f ARC: elf: use right ELF_ARCH
commit b7faf97108 upstream.

Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-16 08:17:27 +02:00
Vineet Gupta
01b636cbc4 ARC: entry: fix potential EFA clobber when TIF_SYSCALL_TRACE
commit 00fdec98d9 upstream.

Trap handler for syscall tracing reads EFA (Exception Fault Address),
in case strace wants PC of trap instruction (EFA is not part of pt_regs
as of current code).

However this EFA read is racy as it happens after dropping to pure
kernel mode (re-enabling interrupts). A taken interrupt could
context-switch, trigger a different task's trap, clobbering EFA for this
execution context.

Fix this by reading EFA early, before re-enabling interrupts. A slight
side benefit is de-duplication of FAKE_RET_FROM_EXCPN in trap handler.
The trap handler is common to both ARCompact and ARCv2 builds too.

This just came out of code rework/review and no real problem was reported
but is clearly a potential problem specially for strace.

Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-16 08:17:27 +02:00
Vineet Gupta
ad722cf7ca ARC: [plat-eznps]: Restrict to CONFIG_ISA_ARCOMPACT
[ Upstream commit 799587d573 ]

Elide invalid configuration EZNPS + ARCv2, triggered by a
make allyesconfig build.

Granted the root cause is in source code (asm/barrier.h) where we check
for ARCv2 before PLAT_EZNPS, but it is better to avoid such combinations
at onset rather then baking subtle nuances into code.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-07 13:17:55 +02:00
Eugeniy Paltsev
c9c1ef681a ARC: Fix ICCM & DCCM runtime size checks
[ Upstream commit 43900edf67 ]

As of today the ICCM and DCCM size checks are incorrectly using
mismatched units (KiB checked against bytes). The CONFIG_ARC_DCCM_SZ
and CONFIG_ARC_ICCM_SZ are in KiB, but the size calculated in
runtime and stored in cpu->dccm.sz and cpu->iccm.sz is in bytes.

Fix that.

Reported-by: Paul Greco <pmgreco@us.ibm.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-07 13:17:55 +02:00
Eugeniy Paltsev
2345c4d769 ARC: define __ALIGN_STR and __ALIGN symbols for ARC
commit 8d92e992a7 upstream.

The default defintions use fill pattern 0x90 for padding which for ARC
generates unintended "ldh_s r12,[r0,0x20]" corresponding to opcode 0x9090

So use ".align 4" which insert a "nop_s" instruction instead.

Cc: stable@vger.kernel.org
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-18 07:14:21 +01:00
Jose Abreu
f2b5542920 ARC: [plat-axs10x]: Add missing multicast filter number to GMAC node
commit 7980dff398 upstream.

Add a missing property to GMAC node so that multicast filtering works
correctly.

Fixes: 556cc1c5f5 ("ARC: [axs101] Add support for AXS101 SDP (software development platform)")
Acked-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:33:25 -05:00
Randy Dunlap
a520839cc6 arc: eznps: fix allmodconfig kconfig warning
[ Upstream commit 1928b36cfa ]

Fix kconfig warning for arch/arc/plat-eznps/Kconfig allmodconfig:

WARNING: unmet direct dependencies detected for CLKSRC_NPS
  Depends on [n]: GENERIC_CLOCKEVENTS [=y] && !PHYS_ADDR_T_64BIT [=y]
  Selected by [y]:
  - ARC_PLAT_EZNPS [=y]

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Ofer Levi <oferle@mellanox.com>
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-01 09:37:06 +00:00
Eugeniy Paltsev
705d1e7331 ARC: IOC: panic if kernel was started with previously enabled IOC
[ Upstream commit 3624379d90 ]

If IOC was already enabled (due to bootloader) it technically needs to
be reconfigured with aperture base,size corresponding to Linux memory map
which will certainly be different than uboot's. But disabling and
reenabling IOC when DMA might be potentially active is tricky business.
To avoid random memory issues later, just panic here and ask user to
upgrade bootloader to one which doesn't enable IOC

This was actually seen as issue on some of the HSDK board with a version
of uboot which enabled IOC. There were random issues later with starting
of X or peripherals etc.

Also while I'm at it, replace hardcoded bits in ARC_REG_IO_COH_PARTIAL
and ARC_REG_IO_COH_ENABLE registers by definitions.

Inspired by: https://lkml.org/lkml/2018/1/19/557
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-13 08:51:12 +01:00
Alexey Brodkin
99b933bbc7 ARC: perf: Accommodate big-endian CPU
commit 5effc09c49 upstream.

8-letter strings representing ARC perf events are stores in two
32-bit registers as ASCII characters like that: "IJMP", "IALL", "IJMPTAK" etc.

And the same order of bytes in the word is used regardless CPU endianness.

Which means in case of big-endian CPU core we need to swap bytes to get
the same order as if it was on little-endian CPU.

Otherwise we're seeing the following error message on boot:
------------------------->8----------------------
ARC perf        : 8 counters (32 bits), 40 conditions, [overflow IRQ support]
sysfs: cannot create duplicate filename '/devices/arc_pct/events/pmji'
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.18 #3
Stack Trace:
  arc_unwind_core+0xd4/0xfc
  dump_stack+0x64/0x80
  sysfs_warn_dup+0x46/0x58
  sysfs_add_file_mode_ns+0xb2/0x168
  create_files+0x70/0x2a0
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at kernel/events/core.c:12144 perf_event_sysfs_init+0x70/0xa0
Failed to register pmu: arc_pct, reason -17
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.18 #3
Stack Trace:
  arc_unwind_core+0xd4/0xfc
  dump_stack+0x64/0x80
  __warn+0x9c/0xd4
  warn_slowpath_fmt+0x22/0x2c
  perf_event_sysfs_init+0x70/0xa0
---[ end trace a75fb9a9837bd1ec ]---
------------------------->8----------------------

What happens here we're trying to register more than one raw perf event
with the same name "PMJI". Why? Because ARC perf events are 4 to 8 letters
and encoded into two 32-bit words. In this particular case we deal with 2
events:
 * "IJMP____" which counts all jump & branch instructions
 * "IJMPC___" which counts only conditional jumps & branches

Those strings are split in two 32-bit words this way "IJMP" + "____" &
"IJMP" + "C___" correspondingly. Now if we read them swapped due to CPU core
being big-endian then we read "PMJI" + "____" & "PMJI" + "___C".

And since we interpret read array of ASCII letters as a null-terminated string
on big-endian CPU we end up with 2 events of the same name "PMJI".

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-01 09:17:37 +01:00
Eugeniy Paltsev
cacbc85376 ARC: mm: SIGSEGV userspace trying to access kernel virtual memory
[ Upstream commit a8c715b4dd ]

As of today if userspace process tries to access a kernel virtual addres
(0x7000_0000 to 0x7ffff_ffff) such that a legit kernel mapping already
exists, that process hangs instead of being killed with SIGSEGV

Fix that by ensuring that do_page_fault() handles kenrel vaddr only if
in kernel mode.

And given this, we can also simplify the code a bit. Now a vmalloc fault
implies kernel mode so its failure (for some reason) can reuse the
@no_context label and we can remove @bad_area_nosemaphore.

Reproduce user test for original problem:

------------------------>8-----------------
 #include <stdlib.h>
 #include <stdint.h>

 int main(int argc, char *argv[])
 {
 	volatile uint32_t temp;

 	temp = *(uint32_t *)(0x70000000);
 }
------------------------>8-----------------

Cc: <stable@vger.kernel.org>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16 08:22:14 +02:00
Eugeniy Paltsev
7edfa9c99d ARC: mm: fix uninitialised signal code in do_page_fault
[ Upstream commit 121e38e5ac ]

Commit 15773ae938 ("signal/arc: Use force_sig_fault where
appropriate") introduced undefined behaviour by leaving si_code
unitiailized and leaking random kernel values to user space.

Fixes: 15773ae938 ("signal/arc: Use force_sig_fault where appropriate")
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16 08:22:14 +02:00
Eric W. Biederman
0828438e52 signal/arc: Use force_sig_fault where appropriate
[ Upstream commit 15773ae938 ]

Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16 08:22:14 +02:00
Vineet Gupta
8c6fb55abf ARC: mm: do_page_fault fixes #1: relinquish mmap_sem if signal arrives while handle_mm_fault
[ Upstream commit 4d447455e7 ]

do_page_fault() forgot to relinquish mmap_sem if a signal came while
handling handle_mm_fault() - due to say a ctl+c or oom etc.
This would later cause a deadlock by acquiring it twice.

This came to light when running libc testsuite tst-tls3-malloc test but
is likely also the cause for prior seen LTP failures. Using lockdep
clearly showed what the issue was.

| # while true; do ./tst-tls3-malloc ; done
| Didn't expect signal from child: got `Segmentation fault'
| ^C
| ============================================
| WARNING: possible recursive locking detected
| 4.17.0+ #25 Not tainted
| --------------------------------------------
| tst-tls3-malloc/510 is trying to acquire lock:
| 606c7728 (&mm->mmap_sem){++++}, at: __might_fault+0x28/0x5c
|
|but task is already holding lock:
|606c7728 (&mm->mmap_sem){++++}, at: do_page_fault+0x9c/0x2a0
|
| other info that might help us debug this:
|  Possible unsafe locking scenario:
|
|       CPU0
|       ----
|  lock(&mm->mmap_sem);
|  lock(&mm->mmap_sem);
|
| *** DEADLOCK ***
|

------------------------------------------------------------
What the change does is not obvious (note to myself)

prior code was

| do_page_fault
|
|   down_read()		<-- lock taken
|   handle_mm_fault	<-- signal pending as this runs
|   if fatal_signal_pending
|       if VM_FAULT_ERROR
|           up_read
|       if user_mode
|          return	<-- lock still held, this was the BUG

New code

| do_page_fault
|
|   down_read()		<-- lock taken
|   handle_mm_fault	<-- signal pending as this runs
|   if fatal_signal_pending
|       if VM_FAULT_RETRY
|          return       <-- not same case as above, but still OK since
|                           core mm already relinq lock for FAULT_RETRY
|    ...
|
|   < Now falls through for bug case above >
|
|   up_read()		<-- lock relinquished

Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16 08:22:02 +02:00
Vineet Gupta
96af7d92d8 ARC: show_regs: lockdep: re-enable preemption
[ Upstream commit f731a8e89f ]

signal handling core calls show_regs() with preemption disabled which
on ARC takes mmap_sem for mm/vma access, causing lockdep splat.

| [ARCLinux]# ./segv-null-ptr
| potentially unexpected fatal signal 11.
| BUG: sleeping function called from invalid context at kernel/fork.c:1011
| in_atomic(): 1, irqs_disabled(): 0, pid: 70, name: segv-null-ptr
| no locks held by segv-null-ptr/70.
| CPU: 0 PID: 70 Comm: segv-null-ptr Not tainted 4.18.0+ #69
|
| Stack Trace:
|  arc_unwind_core+0xcc/0x100
|  ___might_sleep+0x17a/0x190
|  mmput+0x16/0xb8
|  show_regs+0x52/0x310
|  get_signal+0x5ee/0x610
|  do_signal+0x2c/0x218
|  resume_user_mode_begin+0x90/0xd8

Workaround by re-enabling preemption temporarily.

Note that the preemption disabling in core code around show_regs()
was introduced by commit 3a9f84d354 ("signals, debug: fix BUG: using
smp_processor_id() in preemptible code in print_fatal_signal()")

to silence a differnt lockdep seen on x86 bakc in 2009.

Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16 08:22:02 +02:00
Eugeniy Paltsev
89f3896b65 ARC: enable uboot support unconditionally
commit 493a2f8124 upstream.

After reworking U-boot args handling code and adding paranoid
arguments check we can eliminate CONFIG_ARC_UBOOT_SUPPORT and
enable uboot support unconditionally.

For JTAG case we can assume that core registers will come up
reset value of 0 or in worst case we rely on user passing
'-on=clear_regs' to Metaware debugger.

Cc: stable@vger.kernel.org
Tested-by: Corentin LABBE <clabbe@baylibre.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-06 19:06:57 +02:00
Arnd Bergmann
9db915738e ARC: hide unused function unw_hdr_alloc
commit fd5de2721e upstream.

As kernelci.org reports, this function is not used in
vdk_hs38_defconfig:

arch/arc/kernel/unwind.c:188:14: warning: 'unw_hdr_alloc' defined but not used [-Wunused-function]

Fixes: bc79c9a721 ("ARC: dw2 unwind: Reinstante unwinding out of modules")
Link: https://kernelci.org/build/id/5d1cae3f59b514300340c132/logs/
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-21 09:03:14 +02:00
Jose Abreu
7b2145e222 ARC: [plat-hsdk]: Add missing FIFO size entry in GMAC node
[ Upstream commit 4c70850aeb ]

Add the binding for RX/TX fifo size of GMAC node.

Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Tested-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Acked-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-25 11:35:55 +08:00
Jose Abreu
15004afd98 ARC: [plat-hsdk]: Add missing multicast filter bins number to GMAC node
[ Upstream commit ecc906a11c ]

GMAC controller on HSDK boards supports 256 Hash Table size so we need to
add the multicast filter bins property. This allows for the Hash filter
to work properly using stmmac driver.

Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Acked-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-25 11:35:55 +08:00
Vineet Gupta
4c21b761b4 ARC: fix build warnings
[ Upstream commit 89c92142f7 ]

| arch/arc/mm/tlb.c:914:2: warning: variable length array 'pd0' is used [-Wvla]
| arch/arc/include/asm/cmpxchg.h:95:29: warning: value computed is not used [-Wunused-value]

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-25 11:35:55 +08:00
Corentin Labbe
618490ba58 arc: hsdk_defconfig: Enable CONFIG_BLK_DEV_RAM
[ Upstream commit 0728aeb7ea ]

We have now a HSDK device in our kernelci lab, but kernel builded via
the hsdk_defconfig lacks ramfs supports, so it cannot boot kernelci jobs
yet.

So this patch enable CONFIG_BLK_DEV_RAM in hsdk_defconfig.

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Acked-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-20 09:15:54 +02:00
Eugeniy Paltsev
2296eedef0 ARC: u-boot args: check that magic number is correct
[ Upstream commit edb64bca50 ]

In case of devboards we really often disable bootloader and load
Linux image in memory via JTAG. Even if kernel tries to verify
uboot_tag and uboot_arg there is sill a chance that we treat some
garbage in registers as valid u-boot arguments in JTAG case.
E.g. it is enough to have '1' in r0 to treat any value in r2 as
a boot command line.

So check that magic number passed from u-boot is correct and drop
u-boot arguments otherwise. That helps to reduce the possibility
of using garbage as u-boot arguments in JTAG case.

We can safely check U-boot magic value (0x0) in linux passed via
r1 register as U-boot pass it from the beginning. So there is no
backward-compatibility issues.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-20 09:15:54 +02:00
Vineet Gupta
8b9187e7df ARCv2: don't assume core 0x54 has dual issue
[ Upstream commit 7b2e932f63 ]

The first release of core4 (0x54) was dual issue only (HS4x).
Newer releases allow hardware to be configured as single issue (HS3x)
or dual issue.

Prevent accessing a HS4x only aux register in HS3x, which otherwise
leads to illegal instruction exceptions

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-23 20:09:51 +01:00
Vineet Gupta
3220aa9b00 ARCv2: support manual regfile save on interrupts
[ Upstream commit e494239a00 ]

There's a hardware bug which affects the HSDK platform, triggered by
micro-ops for auto-saving regfile on taken interrupt. The workaround is
to inhibit autosave.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-23 20:09:51 +01:00
Vineet Gupta
74b4dcea67 ARC: uacces: remove lp_start, lp_end from clobber list
[ Upstream commit d5e3c55e01 ]

Newer ARC gcc handles lp_start, lp_end in a different way and doesn't
like them in the clobber list.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-23 20:09:51 +01:00
Eugeniy Paltsev
2fc69e55f3 ARCv2: lib: memcpy: fix doing prefetchw outside of buffer
[ Upstream commit f8a15f9766 ]

ARCv2 optimized memcpy uses PREFETCHW instruction for prefetching the
next cache line but doesn't ensure that the line is not past the end of
the buffer. PRETECHW changes the line ownership and marks it dirty,
which can cause data corruption if this area is used for DMA IO.

Fix the issue by avoiding the PREFETCHW. This leads to performance
degradation but it is OK as we'll introduce new memcpy implementation
optimized for unaligned memory access using.

We also cut off all PREFETCH instructions at they are quite useless
here:
 * we call PREFETCH right before LOAD instruction call.
 * we copy 16 or 32 bytes of data (depending on CONFIG_ARC_HAS_LL64)
   in a main logical loop. so we call PREFETCH 4 times (or 2 times)
   for each L1 cache line (in case of 64B L1 cache Line which is
   default case). Obviously this is not optimal.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-23 20:09:51 +01:00
Vineet Gupta
4749ffdfbb ARC: show_regs: lockdep: avoid page allocator...
[ Upstream commit ab6c03676c ]

and use smaller/on-stack buffer instead

The motivation for this change was lockdep splat like below.

| potentially unexpected fatal signal 11.
| BUG: sleeping function called from invalid context at ../mm/page_alloc.c:4317
| in_atomic(): 1, irqs_disabled(): 0, pid: 57, name: segv
| no locks held by segv/57.
| Preemption disabled at:
| [<8182f17e>] get_signal+0x4a6/0x7c4
| CPU: 0 PID: 57 Comm: segv Not tainted 4.17.0+ #23
|
| Stack Trace:
|  arc_unwind_core.constprop.1+0xd0/0xf4
|  __might_sleep+0x1f6/0x234
|  __get_free_pages+0x174/0xca0
|  show_regs+0x22/0x330
|  get_signal+0x4ac/0x7c4     # print_fatal_signals() -> preempt_disable()
|  do_signal+0x30/0x224
|  resume_user_mode_begin+0x90/0xd8

So signal handling core calls show_regs() with preemption disabled but
an ensuing GFP_KERNEL page allocator call is flagged by lockdep.

We could have switched to GFP_NOWAIT, but turns out that is not enough
anways and eliding page allocator call leads to less code and
instruction traces to sift thru when debugging pesky crashes.

FWIW, this patch doesn't cure the lockdep splat (which next patch does).

Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-05 17:58:48 +01:00
Eugeniy Paltsev
4e34dd3794 ARC: fix __ffs return value to avoid build warnings
[ Upstream commit 4e868f8419 ]

|  CC      mm/nobootmem.o
|In file included from ./include/asm-generic/bug.h:18:0,
|                 from ./arch/arc/include/asm/bug.h:32,
|                 from ./include/linux/bug.h:5,
|                 from ./include/linux/mmdebug.h:5,
|                 from ./include/linux/gfp.h:5,
|                 from ./include/linux/slab.h:15,
|                 from mm/nobootmem.c:14:
|mm/nobootmem.c: In function '__free_pages_memory':
|./include/linux/kernel.h:845:29: warning: comparison of distinct pointer types lacks a cast
|   (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
|                             ^
|./include/linux/kernel.h:859:4: note: in expansion of macro '__typecheck'
|   (__typecheck(x, y) && __no_side_effects(x, y))
|    ^~~~~~~~~~~
|./include/linux/kernel.h:869:24: note: in expansion of macro '__safe_cmp'
|  __builtin_choose_expr(__safe_cmp(x, y), \
|                        ^~~~~~~~~~
|./include/linux/kernel.h:878:19: note: in expansion of macro '__careful_cmp'
| #define min(x, y) __careful_cmp(x, y, <)
|                   ^~~~~~~~~~~~~
|mm/nobootmem.c:104:11: note: in expansion of macro 'min'
|   order = min(MAX_ORDER - 1UL, __ffs(start));

Change __ffs return value from 'int' to 'unsigned long' as it
is done in other implementations (like asm-generic, x86, etc...)
to avoid build-time warnings in places where type is strictly
checked.

As __ffs may return values in [0-31] interval changing return
type to unsigned is valid.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-05 17:58:48 +01:00
Alexey Brodkin
95aed87b9e ARC: define ARCH_SLAB_MINALIGN = 8
commit b6835ea777 upstream.

The default value of ARCH_SLAB_MINALIGN in "include/linux/slab.h" is
"__alignof__(unsigned long long)" which for ARC unexpectedly turns out
to be 4. This is not a compiler bug, but as defined by ARC ABI [1]

Thus slab allocator would allocate a struct which is 32-bit aligned,
which is generally OK even if struct has long long members.
There was however potetial problem when it had any atomic64_t which
use LLOCKD/SCONDD instructions which are required by ISA to take
64-bit addresses. This is the problem we ran into

[    4.015732] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)
[    4.167881] Misaligned Access
[    4.172356] Path: /bin/busybox.nosuid
[    4.176004] CPU: 2 PID: 171 Comm: rm Not tainted 4.19.14-yocto-standard #1
[    4.182851]
[    4.182851] [ECR   ]: 0x000d0000 => Check Programmer's Manual
[    4.190061] [EFA   ]: 0xbeaec3fc
[    4.190061] [BLINK ]: ext4_delete_entry+0x210/0x234
[    4.190061] [ERET  ]: ext4_delete_entry+0x13e/0x234
[    4.202985] [STAT32]: 0x80080002 : IE K
[    4.207236] BTA: 0x9009329c   SP: 0xbe5b1ec4  FP: 0x00000000
[    4.212790] LPS: 0x9074b118  LPE: 0x9074b120 LPC: 0x00000000
[    4.218348] r00: 0x00000040  r01: 0x00000021 r02: 0x00000001
...
...
[    4.270510] Stack Trace:
[    4.274510]   ext4_delete_entry+0x13e/0x234
[    4.278695]   ext4_rmdir+0xe0/0x238
[    4.282187]   vfs_rmdir+0x50/0xf0
[    4.285492]   do_rmdir+0x9e/0x154
[    4.288802]   EV_Trap+0x110/0x114

The fix is to make sure slab allocations are 64-bit aligned.

Do note that atomic64_t is __attribute__((aligned(8)) which means gcc
does generate 64-bit aligned references, relative to beginning of
container struct. However the issue is if the container itself is not
64-bit aligned, atomic64_t ends up unaligned which is what this patch
ensures.

[1] https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/wiki/files/ARCv2_ABI.pdf

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: <stable@vger.kernel.org> # 4.8+
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: reworked changelog, added dependency on LL64+LLSC]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-27 10:09:00 +01:00
Eugeniy Paltsev
7779566abb ARC: U-boot: check arguments paranoidly
commit a66f2e57bd upstream.

Handle U-boot arguments paranoidly:
 * don't allow to pass unknown tag.
 * try to use external device tree blob only if corresponding tag
   (TAG_DTB) is set.
 * don't check uboot_tag if kernel build with no ARC_UBOOT_SUPPORT.

NOTE:
If U-boot args are invalid we skip them and try to use embedded device
tree blob. We can't panic on invalid U-boot args as we really pass
invalid args due to bug in U-boot code.
This happens if we don't provide external DTB to U-boot and
don't set 'bootargs' U-boot environment variable (which is default
case at least for HSDK board) In that case we will pass
{r0 = 1 (bootargs in r2); r1 = 0; r2 = 0;} to linux which is invalid.

While I'm at it refactor U-boot arguments handling code.

Cc: stable@vger.kernel.org
Tested-by: Corentin LABBE <clabbe@baylibre.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-27 10:09:00 +01:00
Eugeniy Paltsev
5f7814c0ae ARCv2: Enable unaligned access in early ASM code
commit 252f6e8eae upstream.

It is currently done in arc_init_IRQ() which might be too late
considering gcc 7.3.1 onwards (GNU 2018.03) generates unaligned
memory accesses by default

Cc: stable@vger.kernel.org #4.4+
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: rewrote changelog]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-27 10:09:00 +01:00
Eugeniy Paltsev
8cbca17381 ARC: perf: map generic branches to correct hardware condition
commit 3affbf0e15 upstream.

So far we've mapped branches to "ijmp" which also counts conditional
branches NOT taken. This makes us different from other architectures
such as ARM which seem to be counting only taken branches.

So use "ijmptak" hardware condition which only counts (all jump
instructions that are taken)

'ijmptak' event is available on both ARCompact and ARCv2 ISA based
cores.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: reworked changelog]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-31 08:14:35 +01:00
Eugeniy Paltsev
2f0d2f3ace ARC: adjust memblock_reserve of kernel memory
commit a3010a0465 upstream.

In setup_arch_memory we reserve the memory area wherein the kernel
is located. Current implementation may reserve more memory than
it actually required in case of CONFIG_LINUX_LINK_BASE is not
equal to CONFIG_LINUX_RAM_BASE. This happens because we calculate
start of the reserved region relatively to the CONFIG_LINUX_RAM_BASE
and end of the region relatively to the CONFIG_LINUX_RAM_BASE.

For example in case of HSDK board we wasted 256MiB of physical memory:
------------------->8------------------------------
Memory: 770416K/1048576K available (5496K kernel code,
    240K rwdata, 1064K rodata, 2200K init, 275K bss,
    278160K reserved, 0K cma-reserved)
------------------->8------------------------------

Fix that.

Fixes: 9ed68785f7 ("ARC: mm: Decouple RAM base address from kernel link addr")
Cc: stable@vger.kernel.org	#4.14+
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-31 08:14:35 +01:00
Eugeniy Paltsev
7bb78e62f7 ARCv2: lib: memeset: fix doing prefetchw outside of buffer
commit e6a72b7dae upstream.

ARCv2 optimized memset uses PREFETCHW instruction for prefetching the
next cache line but doesn't ensure that the line is not past the end of
the buffer. PRETECHW changes the line ownership and marks it dirty,
which can cause issues in SMP config when next line was already owned by
other core. Fix the issue by avoiding the PREFETCHW

Some more details:

The current code has 3 logical loops (ignroing the unaligned part)
  (a) Big loop for doing aligned 64 bytes per iteration with PREALLOC
  (b) Loop for 32 x 2 bytes with PREFETCHW
  (c) any left over bytes

loop (a) was already eliding the last 64 bytes, so PREALLOC was
safe. The fix was removing PREFETCW from (b).

Another potential issue (applicable to configs with 32 or 128 byte L1
cache line) is that PREALLOC assumes 64 byte cache line and may not do
the right thing specially for 32b. While it would be easy to adapt,
there are no known configs with those lie sizes, so for now, just
compile out PREALLOC in such cases.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Cc: stable@vger.kernel.org #4.4+
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: rewrote changelog, used asm .macro vs. "C" macro]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-31 08:14:35 +01:00
Alexey Brodkin
bf75d9382b clocksource/drivers/arc_timer: Utilize generic sched_clock
commit bf287607c8 upstream.

It turned out we used to use default implementation of sched_clock()
from kernel/sched/clock.c which was as precise as 1/HZ, i.e.
by default we had 10 msec granularity of time measurement.

Now given ARC built-in timers are clocked with the same frequency as
CPU cores we may get much higher precision of time tracking.

Thus we switch to generic sched_clock which really reads ARC hardware
counters.

This is especially helpful for measuring short events.
That's what we used to have:
------------------------------>8------------------------
$ perf stat /bin/sh -c /root/lmbench-master/bin/arc/hello > /dev/null

 Performance counter stats for '/bin/sh -c /root/lmbench-master/bin/arc/hello':

         10.000000      task-clock (msec)         #    2.832 CPUs utilized
                 1      context-switches          #    0.100 K/sec
                 1      cpu-migrations            #    0.100 K/sec
                63      page-faults               #    0.006 M/sec
           3049480      cycles                    #    0.305 GHz
           1091259      instructions              #    0.36  insn per cycle
            256828      branches                  #   25.683 M/sec
             27026      branch-misses             #   10.52% of all branches

       0.003530687 seconds time elapsed

       0.000000000 seconds user
       0.010000000 seconds sys
------------------------------>8------------------------

And now we'll see:
------------------------------>8------------------------
$ perf stat /bin/sh -c /root/lmbench-master/bin/arc/hello > /dev/null

 Performance counter stats for '/bin/sh -c /root/lmbench-master/bin/arc/hello':

          3.004322      task-clock (msec)         #    0.865 CPUs utilized
                 1      context-switches          #    0.333 K/sec
                 1      cpu-migrations            #    0.333 K/sec
                63      page-faults               #    0.021 M/sec
           2986734      cycles                    #    0.994 GHz
           1087466      instructions              #    0.36  insn per cycle
            255209      branches                  #   84.947 M/sec
             26002      branch-misses             #   10.19% of all branches

       0.003474829 seconds time elapsed

       0.003519000 seconds user
       0.000000000 seconds sys
------------------------------>8------------------------

Note how much more meaningful is the second output - time spent for
execution pretty much matches number of cycles spent (we're runnign
@ 1GHz here).

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09 17:38:42 +01:00
Jose Abreu
bf69dc3cb1 ARC: io.h: Implement reads{x}()/writes{x}()
[ Upstream commit 10d443431d ]

Some ARC CPU's do not support unaligned loads/stores. Currently, generic
implementation of reads{b/w/l}()/writes{b/w/l}() is being used with ARC.
This can lead to misfunction of some drivers as generic functions do a
plain dereference of a pointer that can be unaligned.

Let's use {get/put}_unaligned() helpers instead of plain dereference of
pointer in order to fix. The helpers allow to get and store data from an
unaligned address whilst preserving the CPU internal alignment.
According to [1], the use of these helpers are costly in terms of
performance so we added an initial check for a buffer already aligned so
that the usage of the helpers can be avoided, when possible.

[1] Documentation/unaligned-memory-access.txt

Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Tested-by: Vitor Soares <soares@synopsys.com>
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-21 14:15:16 +01:00
Alexey Brodkin
4e84cccacb arc: [devboards] Add support of NFSv3 ACL
commit 6b04114f6f upstream.

By default NFSv3 doesn't support ACL (Access Control Lists)
which might be quite convenient to have so that
mounted NFS behaves exactly as any other local file-system.

In particular missing support of ACL makes umask useless.
This among other thigs fixes Glibc's "nptl/tst-umask1".

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Cupertino Miranda <cmiranda@synopsys.com>
Cc: stable@vger.kernel.org	#4.14+
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-08 12:59:10 +01:00
Kevin Hilman
41e0254d32 ARC: change defconfig defaults to ARCv2
commit b7cc40c32a upstream.

Change the default defconfig (used with 'make defconfig') to the ARCv2
nsim_hs_defconfig, and also switch the default Kconfig ISA selection to
ARCv2.

This allows several default defconfigs (e.g. make defconfig, make
allnoconfig, make tinyconfig) to all work with ARCv2 by default.

Note since we change default architecture from ARCompact to ARCv2
it's required to explicitly mention architecture type in ARCompact
defconfigs otherwise ARCv2 will be implied and binaries will be
generated for ARCv2.

Cc: <stable@vger.kernel.org> # 4.4.x
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-08 12:59:10 +01:00
Vineet Gupta
c58a584f05 ARC: clone syscall to setp r25 as thread pointer
Per ARC TLS ABI, r25 is designated TP (thread pointer register).
However so far kernel didn't do any special treatment, like setting up
usermode r25, even for CLONE_SETTLS. We instead relied on libc runtime
to do this, in say clone libc wrapper [1]. This was deliberate to keep
kernel ABI agnostic (userspace could potentially change TP, specially
for different ARC ISA say ARCompact vs. ARCv2 with different spare
registers etc)

However userspace setting up r25, after clone syscall opens a race, if
child is not scheduled and gets a signal instead. It starts off in
userspace not in clone but in a signal handler and anything TP sepcific
there such as pthread_self() fails which showed up with uClibc
testsuite nptl/tst-kill6 [2]

Fix this by having kernel populate r25 to TP value. So this locks in
ABI, but it was not going to change anyways, and fwiw is same for both
ARCompact (arc700 core) and ARCvs (HS3x cores)

[1] https://cgit.uclibc-ng.org/cgi/cgit/uclibc-ng.git/tree/libc/sysdeps/linux/arc/clone.S
[2] https://github.com/wbx-github/uclibc-ng-test/blob/master/test/nptl/tst-kill6.c

Fixes: ARC STAR 9001378481
Cc: stable@vger.kernel.org
Reported-by: Nikita Sobolev <sobolev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2018-10-05 14:33:29 -07:00
Alexey Brodkin
40660f1fce ARC: build: Don't set CROSS_COMPILE in arch's Makefile
There's not much sense in doing that because if user or
his build-system didn't set CROSS_COMPILE we still may
very well make incorrect guess.

But as it turned out setting CROSS_COMPILE is not as harmless
as one may think: with recent changes that implemented automatic
discovery of __host__ gcc features unconditional setup of
CROSS_COMPILE leads to failures on execution of "make xxx_defconfig"
with absent cross-compiler, for more info see [1].

Set CROSS_COMPILE as well gets in the way if we want only to build
.dtb's (again with absent cross-compiler which is not really needed
for building .dtb's), see [2].

Note, we had to change LIBGCC assignment type from ":=" to "="
so that is is resolved on its usage, otherwise if it is resolved
at declaration time with missing CROSS_COMPILE we're getting this
error message from host GCC:

| gcc: error: unrecognized command line option -mmedium-calls
| gcc: error: unrecognized command line option -mno-sdata

[1] http://lists.infradead.org/pipermail/linux-snps-arc/2018-September/004308.html
[2] http://lists.infradead.org/pipermail/linux-snps-arc/2018-September/004320.html

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2018-09-18 13:24:34 -07:00
Colin Ian King
7c2020c302 ARC: fix spelling mistake "entires" -> "entries"
Trivial fix to spelling mistake in Kconfig

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2018-09-14 10:32:49 -07:00
Alexey Brodkin
615f64458a ARC: build: Get rid of toolchain check
This check is very naive: we simply test if GCC invoked without
"-mcpu=XXX" has ARC700 define set. In that case we think that GCC
was built with "--with-cpu=arc700" and has libgcc built for ARC700.

Otherwise if ARC700 is not defined we think that everythng was built
for ARCv2.

But in reality our life is much more interesting.

1. Regardless of GCC configuration (i.e. what we pass in "--with-cpu"
   it may generate code for any ARC core).

2. libgcc might be built with explicitly specified "--mcpu=YYY"

That's exactly what happens in case of multilibbed toolchains:
 - GCC is configured with default settings
 - All the libs built for many different CPU flavors

I.e. that check gets in the way of usage of multilibbed
toolchains. And even non-multilibbed toolchains are affected.
OpenEmbedded also builds GCC without "--with-cpu" because
each and every target component later is compiled with explicitly
set "-mcpu=ZZZ".

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2018-09-13 14:48:05 -07:00
Vineet Gupta
00a99339f0 ARCv2: build: use mcpu=hs38 iso generic mcpu=archs
helps gcc with better instruction selections such as 64-bit multiply MPYD

before
------
82c34b58 <sched_clock>:
82c34b58:	ld	r2,[0x83068d00]
82c34b60:	add_s	r2,r2,0x7530
82c34b66:	mov_s	r0,0x989680
82c34b6c:	mpymu	r5,r2,r0
82c34b70:	mpy	r4,r2,r0
82c34b74:	mov_s	r0,r4
82c34b76:	j_s.d	[blink]
82c34b78:	mov_s	r1,r5
82c34b7a:	nop_s

after
------
82c34b7c <sched_clock>:
82c34b7c:	ld	r0,[0x83064d00]
82c34b84:	add_s	r0,r0,0x7530
82c34b8a:	mpydu	r0,r0,0x989680
82c34b92:	j_s	[blink]

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2018-09-10 09:25:38 -07:00
Eugeniy Paltsev
dd45210b6d ARC: don't check for HIGHMEM pages in arch_dma_alloc
__GFP_HIGHMEM flag is cleared by upper layer functions
(in include/linux/dma-mapping.h) so we'll never get a
__GFP_HIGHMEM flag in arch_dma_alloc gfp argument.
That's why alloc_pages will never return highmem page
here.

Get rid of highmem pages handling and cleanup arch_dma_alloc
and arch_dma_free functions.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2018-09-04 13:21:38 -07:00
Eugeniy Paltsev
2b720e99a1 ARC: IOC: panic if both IOC and ZONE_HIGHMEM enabled
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2018-09-04 13:21:37 -07:00
Eugeniy Paltsev
2820a708d5 ARC: dma [IOC] Enable per device io coherency
So far the IOC treatment was global on ARC, being turned on (or off)
for all devices in the system. With this patch, this can now be done
per device using the "dma-coherent" DT property; IOW with this patch
we can use both HW-coherent and regular DMA peripherals simultaneously.

The changes involved are too many so enlisting the summary below:

1. common code calls ARC arch_setup_dma_ops() per device.

2. For coherent dma (IOC) it plugs in generic @dma_direct_ops which
   doesn't need any arch specific backend: No need for any explicit
   cache flushes or MMU mappings to provide for uncached access

   - dma_(map|sync)_single* return early as corresponding dma ops callbacks
     are NULL in generic code.
     So arch_sync_dma_*() -> dma_cache_*() need not handle the coherent
     dma case, hence drop ARC __dma_cache_*_ioc() which were no-op anyways

3. For noncoherent dma (non IOC) generic @dma_noncoherent_ops is used
   which in turns calls ARC specific routines

   - arch_dma_alloc() no longer checks for @ioc_enable since this is
     called only for !IOC case.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: rewrote changelog]
2018-09-04 13:21:37 -07:00
Eugeniy Paltsev
678c8110d2 ARC: dma [IOC]: mark DMA devices connected as dma-coherent
Mark DMA devices on AXS103 and HSDK boards connected through IOC
port as dma-coherent.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2018-08-31 12:47:26 -07:00
Will Deacon
3fcbb8260a ARC: atomics: unbork atomic_fetch_##op()
In 4.19-rc1, Eugeniy reported weird boot and IO errors on ARC HSDK

| INFO: task syslogd:77 blocked for more than 10 seconds.
|       Not tainted 4.19.0-rc1-00007-gf213acea4e88 #40
| "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
| message.
| syslogd         D    0    77     76 0x00000000
|
| Stack Trace:
|  __switch_to+0x0/0xac
|  __schedule+0x1b2/0x730
|  io_schedule+0x5c/0xc0
|  __lock_page+0x98/0xdc
|  find_lock_entry+0x38/0x100
|  shmem_getpage_gfp.isra.3+0x82/0xbfc
|  shmem_fault+0x46/0x138
|  handle_mm_fault+0x5bc/0x924
|  do_page_fault+0x100/0x2b8
|  ret_from_exception+0x0/0x8

He bisected to 84c6591103 ("locking/atomics,
asm-generic/bitops/lock.h: Rewrite using atomic_fetch_*()")

This commit however only unmasked the real issue introduced by commit
4aef66c8ae ("locking/atomic, arch/arc: Fix build") which missed the
retry-if-scond-failed branch in atomic_fetch_##op() macros.

The bisected commit started using atomic_fetch_##op() macros for building
the rest of atomics.

Fixes: 4aef66c8ae ("locking/atomic, arch/arc: Fix build")
Reported-by: Eugeniy Paltsev <paltsev@synopsys.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: wrote changelog]
2018-08-31 10:14:51 -07:00