GFP_TEMPORARY was introduced by commit e12ba74d8f ("Group short-lived
and reclaimable kernel allocations") along with __GFP_RECLAIMABLE. It's
primary motivation was to allow users to tell that an allocation is
short lived and so the allocator can try to place such allocations close
together and prevent long term fragmentation. As much as this sounds
like a reasonable semantic it becomes much less clear when to use the
highlevel GFP_TEMPORARY allocation flag. How long is temporary? Can the
context holding that memory sleep? Can it take locks? It seems there is
no good answer for those questions.
The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
__GFP_RECLAIMABLE which in itself is tricky because basically none of
the existing caller provide a way to reclaim the allocated memory. So
this is rather misleading and hard to evaluate for any benefits.
I have checked some random users and none of them has added the flag
with a specific justification. I suspect most of them just copied from
other existing users and others just thought it might be a good idea to
use without any measuring. This suggests that GFP_TEMPORARY just
motivates for cargo cult usage without any reasoning.
I believe that our gfp flags are quite complex already and especially
those with highlevel semantic should be clearly defined to prevent from
confusion and abuse. Therefore I propose dropping GFP_TEMPORARY and
replace all existing users to simply use GFP_KERNEL. Please note that
SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
so they will be placed properly for memory fragmentation prevention.
I can see reasons we might want some gfp flag to reflect shorterm
allocations but I propose starting from a clear semantic definition and
only then add users with proper justification.
This was been brought up before LSF this year by Matthew [1] and it
turned out that GFP_TEMPORARY really doesn't have a clear semantic. It
seems to be a heuristic without any measured advantage for most (if not
all) its current users. The follow up discussion has revealed that
opinions on what might be temporary allocation differ a lot between
developers. So rather than trying to tweak existing users into a
semantic which they haven't expected I propose to simply remove the flag
and start from scratch if we really need a semantic for short term
allocations.
[1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org
[akpm@linux-foundation.org: fix typo]
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: drm/i915: fix up]
Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some of the boot printing code had printk() w/o explicit log level.
This patch introduces consistency allowing platforms to switch to less
verbose console logging using cmdline.
NPS400 with 4K CPUs needs to avoid the cpu info printing for faster
bootup.
Signed-off-by: Noam Camus <noamca@mellanox.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The function name is now renamed to 'timer_probe' for consistency with
the CLOCKSOURCE_OF_DECLARE => TIMER_OF_DECLARE change.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Accumulator is present in configs with FPU and/or DSP MPY (mpy > 6)
Instead of doing this in pt_regs (and thus every kernel entry/exit),
this could have been done in context switch (and for user task only) as
currently kernel doesn't clobber these registers for its own accord.
However we will soon start using 64-bit multiply instructions for kernel
which can clobber these. Also gcc folks also plan to start using these
as GPRs, hence better to always save/restore them
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
We were reading clock rate directly from device tree "clock-frequency"
property of corresponding clock node in show_cpuinfo function.
Such approach is correct only in case cpu is always clocked by
"fixed-clock". If we use clock driver that allows rate to be changed
this won't work as rate may change during the time or even
"clock-frequency" property may not be presented at all.
So this commit replaces reading device tree with getting rate from clock
driver. This approach is much more flexible and will work for both fixed
and mutable clocks.
Signed-off-by: Vlad Zakharov <vzakhar@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
to allow future git mv of the driver into drivers/clocksource
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The original distinction was done as they were developed at different
times and primarily because they are specific to UP (RTC) and SMP (GFRC).
But given that driver handles that at runtime, (i.e. not allowing
RTC as clocksource in SMP), we can simplify things a bit.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The motivation is to identify ARC750 vs. ARC770 (we currently print
generic "ARC700").
A given ARC700 release could be 750 or 770, with same ARCNUM (or family
identifier which is unfortunate). The existing arc_cpu_tbl[] kept a single
concatenated string for core name and release which thus doesn't work
for 750 vs. 770 identification.
So split this into 2 tables, one with core names and other with release.
And while we are at it, get rid of the range checking for family numbers.
We just document the known to exist cores running Linux and ditch
others.
With this in place, we add detection of ARC750 which is
- cores 0x33 and before
- cores 0x34 and later with MMUv2
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This came to light when helping a customer with oldish ARC750 core who
were getting instruction errors because of lack of SWAPE but boot log
was incorrectly printing it as being present
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
On older arc700 cores, some of the features configured were not present
in Build config registers. To print about them at boot, we just use the
Kconfig option i.e. whether linux is built to use them or not.
So yes this seems bogus, but what else can be done. Moreover if linux is
booting with these enabled, then the Kconfig info is a good indicator
anyways.
Over time these "hacks" accumulated in read_arc_build_cfg_regs() as well
as arc_cpu_mumbojumbo(). so refactor and move all of those in a single
place: read_arc_build_cfg_regs(). This causes some code redcution too:
| bloat-o-meter2 arch/arc/kernel/setup.o.0 arch/arc/kernel/setup.o.1
| add/remove: 0/0 grow/shrink: 2/1 up/down: 64/-132 (-68)
| function old new delta
| setup_processor 610 670 +60
| cpuinfo_arc700 76 80 +4
| arc_cpu_mumbojumbo 752 620 -132
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Previously we would not print the case when IOC existed but was not
enabled.
And while at it, reduce one line off boot printing by consolidating
the Peripheral address space and IO-Coherency which in a way
applies to them
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
num_possible_cpus() returns how many CPUs may be present on system.
However we want the highest possible CPU number.
This may be differ in a sparsed possible CPUs map.
Such map achived by OF for plat-eznps.
For example if we have:
possible cpus mask 0,3
Then:
num_possible_cpus() is equal 2
while
nr_cpu_ids is equal 4.
Only for value 4 c_start() will provide correct cpuinfo at procfs.
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
HS release 3.0 provides for even more flexibility in specifying the
volatile address space for mapping peripherals.
With HS 2.1 @start was made flexible / programmable - with HS 3.0 even
@end can be setup (vs. fixed to 0xFFFF_FFFF before).
So add code to reflect that and while at it remove an unused struct
defintion
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The syscall ABI includes the gcc functional calling ABI since a syscall
implies userland caller and kernel callee.
The current gcc ABI (v3) for ARCv2 ISA required 64-bit data be passed in
even-odd register pairs, (potentially punching reg holes when passing such
values as args). This was partly driven by the fact that the double-word
LDD/STD instructions in ARCv2 expect the register alignment and thus gcc
forcing this avoids extra MOV at the cost of a few unused register (which we
have plenty anyways).
This however was rejected as part of upstreaming gcc port to HS. So the new
ABI v4 doesn't enforce the even-odd reg restriction.
Do note that for ARCompact ISA builds v3 and v4 are practically the same in
terms of gcc code generation.
In terms of change management, we infer the new ABI if gcc 6.x onwards
is used for building the kernel.
This also needs a stable backport to enable older kernels to work with
new tools/user-space
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
- Removal of most of_platform_populate() calls in arch code. Now the DT
core code calls it in the default case and platforms only need to call
it if they have special needs.
- Use pr_fmt on all the DT core print statements.
- CoreSight binding doc improvements to block name descriptions.
- Add dt_to_config script which can parse dts files and list
corresponding kernel config options.
- Fix memory leak hit with a PowerMac DT.
- Correct a bunch of STMicro compatible strings to use the correct
vendor prefix.
- Fix DA9052 PMIC binding doc to match what is actually used in dts
files.
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Merge tag 'devicetree-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull DeviceTree updates from Rob Herring:
- remove most of_platform_populate() calls in arch code. Now the DT
core code calls it in the default case and platforms only need to
call it if they have special needs
- use pr_fmt on all the DT core print statements
- CoreSight binding doc improvements to block name descriptions
- add dt_to_config script which can parse dts files and list
corresponding kernel config options
- fix memory leak hit with a PowerMac DT
- correct a bunch of STMicro compatible strings to use the correct
vendor prefix
- fix DA9052 PMIC binding doc to match what is actually used in dts
files
* tag 'devicetree-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (35 commits)
documentation: da9052: Update regulator bindings names to match DA9052/53 DTS expectations
xtensa: Partially Revert "xtensa: Remove unnecessary of_platform_populate with default match table"
xtensa: Fix build error due to missing include file
MIPS: ath79: Add missing include file
Fix spelling errors in Documentation/devicetree
ARM: dts: fix STMicroelectronics compatible strings
powerpc/dts: fix STMicroelectronics compatible strings
Documentation: dt: i2c: use correct STMicroelectronics vendor prefix
scripts/dtc: dt_to_config - kernel config options for a devicetree
of: fdt: mark unflattened tree as detached
of: overlay: add resolver error prints
coresight: document binding acronyms
Documentation/devicetree: document cavium-pip rx-delay/tx-delay properties
of: use pr_fmt prefix for all console printing
of/irq: Mark initialised interrupt controllers as populated
of: fix memory leak related to safe_name()
Revert "of/platform: export of_default_bus_match_table"
of: unittest: use of_platform_default_populate() to populate default bus
memory: omap-gpmc: use of_platform_default_populate() to populate default bus
bus: uniphier-system-bus: use of_platform_default_populate() to populate default bus
...
After patch "of/platform: Add common method to populate default bus",
it is possible for arch code to remove unnecessary callers of
of_platform_populate with default match table.
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Rob Herring <robh@kernel.org>
We no longer use it and instead a real clk device such as fixed-clk
instance is fed to timers etc.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
[vgupta: broken out of a bigger patch, rewrote changelog]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
- Remove explicit clocksource setup and let it be done by OF framework
by defining CLOCKSOURCE_OF_DECLARE() for various timers
- This allows multiple clocksources to be potentially registered
simultaneouly: previously we could only do one - as all of them had
same arc_counter_setup() routine for registration
- Setup routines also ensure that the underlying timer actually exists.
- Remove some of the panic() calls if underlying timer is NOT detected as
fallback clocksource might still be available
1. If GRFC doesn't exist, jiffies clocksource gets registered anyways
2. if RTC doesn't exist, TIMER1 can take over (as it is always
present)
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
- call clocksource_probe()
- This in turns needs of_clk_init() to be called earlier
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Noam Camus <noamc@ezchip.com>
[vgupta: broken off from a bigger patch]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The peripheral address space is architectural address window which is
uncached and typically used to wire up peripherals.
For ARC700 cores (ARCompact ISA based) this was fixed to 1GB region
0xC000_0000 - 0xFFFF_FFFF.
For ARCv2 based HS38 cores the start address is flexible and can be
0xC, 0xD, 0xE, 0xF 000_000 by programming AUX_NON_VOLATILE_LIMIT reg
(typically done in bootloader)
Further in cas of PAE, the physical address can extend beyond 4GB so
need to confine this check, otherwise all pages beyond 4GB will be
treated as uncached
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Use helper of_platform_default_populate() in linux/of_platform
when possible, instead of calling of_platform_populate() with
the default match table.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
- ARCv2 uses a seperate BCR for {I,D}CCM base address:
ARCompact encoded both base/size in same BCR
- Size encoding in common BCR is different for ARCompact/ARCv2
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
It is unlikely that designs running Linux will not have multiplier.
Further the current support is not complete as tool don't generate a
multilib w/o multiplier.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The fix which removed linear searching of dwarf (because binary lookup
data always exists) missed out on the fact that modules don't get the
binary lookup tables info. This caused unwinding out of modules to stop
working.
So add binary lookup header setup (equivalent of eh_frame_hdr setup) to
modules as well.
While at it, confine the header setup to within unwinder code,
reducing one API exposed out of unwinder code.
Fixes: 2e22502c08 ARC: dw2 unwind: Remove falllback linear search thru FDE entries
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This adds a platform agnostic early SMP init hook which is called on
Master core before calling setup_processor()
setup_arch()
smp_init_cpus()
smp_ops.init_early_smp()
...
setup_processor()
How this helps:
- Used for one time init of certain SMP centric IP blocks, before
calling setup_processor() which probes various bits of core,
possibly including this block
- Currently platforms need to call this IP block init from their
init routines, which doesn't make sense as this is specific to ARC
core and not platform and otherwise requires copy/paste in all
(and hence a possible point of failure)
e.g. MCIP init is called from 2 platforms currently (axs10x and sim)
which will go away once we have this.
This change only adds the hooks but they are empty for now. Next commit
will populate them and remove the explicit init calls from platforms.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This is to workaround the llock/scond livelock
HS38x4 could get into a LLOCK/SCOND livelock in case of multiple overlapping
coherency transactions in the SCU. The exclusive line state keeps rotating
among contenting cores leading to a never ending cycle. So break the cycle
by deferring the retry of failed exclusive access (SCOND). The actual delay
needed is function of number of contending cores as well as the unrelated
coherency traffic from other cores. To keep the code simple, start off with
small delay of 1 which would suffice most cases and in case of contention
double the delay. Eventually the delay is sufficient such that the coherency
pipeline is drained, thus a subsequent exclusive access would succeed.
Link: http://lkml.kernel.org/r/1438612568-28265-1-git-send-email-vgupta@synopsys.com
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
With HS 2.1 release, the peripheral space register no longer contains
the uncached space specifics, causing the kernel to panic early on.
So read the newer NON VOLATILE AUX register to get that info.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* No active users of this flag anymore
* flag itself was no longer usable with new simualtor which acts just like
hardware, not providing the special chip-id = 0xffff which good old
ISS used to do.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
All the platforms do the same thing in init_machine callback so move it
out of callback into caller of callback
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
In light of recent SNAFU with SMP build, allow simple platform to build
as SMP but run UP.
* Remove the dependence on simulation SMP extension to enable quick
build/test iterations of SMP kernel.
* In absence of platform SMP registration, prevent the NULL smp feature
name from borkign the system
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Michal Hocko