PARISC defines /proc/sys/kernel/unaligned-trap to runtime toggle
unaligned access emulation.
The exact mechanics of enablig/disabling are still arch specific, we can
make the sysctl usable by other arches.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
-Originally written by Rajeshwar Ranga
-Derived off of generic unwinder in 2.6.19 and adapted to ARC
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>
ARC common code to enable a SMP system + ISS provided SMP extensions.
ARC700 natively lacks SMP support, hence some of the core features are
are only enabled if SoCs have the necessary h/w pixie-dust. This
includes:
-Inter Processor Interrupts (IPI)
-Cache coherency
-load-locked/store-conditional
...
The low level exception handling would be completely broken in SMP
because we don't have hardware assisted stack switching. Thus a fair bit
of this code is repurposing the MMU_SCRATCH reg for event handler
prologues to keep them re-entrant.
Many thanks to Rajeshwar Ranga for his initial "major" contributions to
SMP Port (back in 2008), and to Noam Camus and Gilad Ben-Yossef for help
with resurrecting that in 3.2 kernel (2012).
Note that this platform code is again singleton design pattern - so
multiple SMP platforms won't build at the moment - this deficiency is
addressed in subsequent patches within this series.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
There is a bit of hack/kludge right now where we disable preemption if a
L2 (High prio) IRQ is taken while L1 (Low prio) is active.
Need to revisit this
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This was part of port buildup strategy from Arnd to have a minimal kernel
at first and then add optional features (stacktracing, ptrace, smp,
kprobes, oprofile....)
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* arc-uart platform device now populated dynamically, using
of_platform_populate() - applies to any other device whatsoever.
* uart in turn requires incore arc-intc to be also present in DT
* A irq-domain needs to be instantiated for IRQ requests by DT probed
device (e.g. arc-uart)
TODO: switch over to linear irq domain once all devs have been
transitioned to DT
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
This is minimal infrastructure needed for devicetree work.
It uses an a sample "skeleton" devicetree - embedded in kernel image -
to print the board, manufacturer by parsing the top-level "compatible"
string.
As of now we don't need any additional "board" specific "machine_desc".
TODO: support interpreting the command line as boot-loader passed dtb
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
N.B. This is old style of hardcoding platform device specific info
in code and it's instantiation thererof using platform_add_devices().
Subsequent patches replace this with DeviceTree based runtime probe.
This patch has been retained just as an example of "don't-do-this" for
newer kernel ports.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
This includes recent changes to make handler "retry" and/or "killable"
The killable (early exit) logic is loosely based on how SH implements it
return if SIGKILL + either of VM_FAULT_OOM or VM_FAULT_RETRY
which is different from Hexagon implementation which would NOT early
exit for
SIGKILL + VM_FAULT_OOM + !VM_FAULT_RETRY
credits: Non executable stack support from Simon Spooner
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC700 MMU provides for tagging TLB entries with a 8-bit ASID to avoid
having to flush the TLB every task switch.
It also allows for a quick way to invalidate all the TLB entries for
task useful for:
* COW sementics during fork()
* task exit()ing
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC700 has VIPT L1 Caches
* Caches don't snoop and are not coherent
* Given the PAGE_SIZE and Cache associativity, we don't support aliasing
D$ configurations (yet), but do allow aliasing I$ configs
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Per Al Viro's "signals for dummies" https://lkml.org/lkml/2012/12/6/366
there are 3 golden rules for (not) restarting syscalls:
" What we need to guarantee is
* restarts do not happen on signals caught in interrupts or exceptions
* restarts do not happen on signals caught in sigreturn()
* restart should happen only once, even if we get through do_signal()
many times."
ARC Port already handled #1, this patch fixes#2 and #3.
We use the additional state in pt_regs->orig_r8 to ckh if restarting
has already been done once.
Thanks to Al Viro for spotting this.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
To avoid multiple syscall restarts (multiple signals) or no restart at
all (sigreturn), we need just an extra bit of state "literally 1 bit" in
struct pt_regs. orig_r8 is the best place to do this, however given the
way it is encoded currently, we can't add anything simplistically.
Current orig_r8:
* syscalls -> 1 to NR_SYSCALLS
* Exceptions -> NR_SYSCALLS + 1
* Break-point-> NR_SYSCALLS + 2
In new scheme it is a bit-field
* lower short word contains the exact event type (and a new bit to represent
restart semantics : if syscall was already / can't be restarted)
* upper short word optionally containing the syscall num - needed by
likes of tracehooks etc
This patch only changes how orig_r8 is organised and nothing should
change behaviourily.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Includes following fixes courtesy review by Al-Viro
* Tracer poke to Callee-regs were lost
Before going off into do_signal( ) we save the user-mode callee regs
(as they are not saved by default as part of pt_regs). This is to make
sure that that a Tracer (if tracing related signal) is able to do likes
of PEEKUSR(callee-reg).
However in return path we were simply discarding the user-mode callee
regs, which would break a POKEUSR(callee-reg) from a tracer.
* Issue related to multiple syscall restarts are addressed in next patch
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Jonas Bonn <jonas@southpole.se>
ARC700 includes 2 in-core 32bit timers TIMER0 and TIMER1.
Both have exactly same capabilies.
* programmable to count from TIMER<n>_CNT to TIMER<n>_LIMIT
* for count 0 and LIMIT ~1, provides a free-running counter by
auto-wrapping when limit is reached.
* optionally interrupt when LIMIT is reached (oneshot event semantics)
* rearming the interrupt provides periodic semantics
* run at CPU clk
ARC Linux uses TIMER0 for clockevent (periodic/oneshot) and TIMER1 for
clocksource (free-running clock).
Newer cores provide RTSC insn which gives a 64bit cpu clk snapshot hence
is more apt for clocksource when available.
SMP poses a bit of challenge for global timekeeping clocksource /
sched_clock() backend:
-TIMER1 based local clocks are out-of-sync hence can't be used
(thus we default to jiffies based cs as well as sched_clock() one/both
of which platform can override with it's specific hardware assist)
-RTSC is only allowed in SMP if it's cross-core-sync (Kconfig glue
ensures that) and thus usable for both requirements.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
This includes support for generic clone/for/vfork/execve
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Hand optimised asm code for ARC700 pipeline.
Originally written/optimized by Joern Rennecke
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Joern Rennecke <joern.rennecke@embecosm.com>
* L1_CACHE_SHIFT
* PAGE_SIZE, PAGE_OFFSET
* struct pt_regs, struct user_regs_struct
* struct thread_struct, cpu_relax(), task_pt_regs(), start_thread(), ...
* struct thread_info, THREAD_SIZE, INIT_THREAD_INFO(), TIF_*, ...
* BUG()
* ELF_*
* Elf_*
To disallow user-space visibility into some of the core kernel data-types
such as struct pt_regs, #ifdef __KERNEL__ which also makes the UAPI header
spit (further patch in the series) to NOT export it to asm/uapi/ptrace.h
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Jonas Bonn <jonas.bonn@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Override asm-generic implementations. We basically gain on 2 fronts
* checks for alignment no longer needed as we are only doing "unit"
sized copies.
(Careful observer could argue that While the kernel buffers are aligned,
the user buffer in theory might not be - however in that case the
user space is already broken when it tries to deref a hword/word
straddling word boundary - so we are not making it any worse).
* __copy_{to,from}_user( ) returns bytes that couldn't be copied,
whereas get_user() returns 0 for success or -EFAULT (not size). Thus
the code to do leftover bytes calculation can be avoided as well.
The savings were significant: ~17k of code.
bloat-o-meter vmlinux_uaccess_pre vmlinux_uaccess_post
add/remove: 0/4 grow/shrink: 8/118 up/down: 1262/-18758 (-17496)
^^^^^^^^^
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
This covers the UP / SMP (with no hardware assist for atomic r-m-w) as
well as ARC700 LLOCK/SCOND insns based.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC700 has an in-core intc which provides 2 priorities (a.k.a.) "levels"
of interrupts (per IRQ) hencforth referred to as L1/L2 interrupts.
CPU flags register STATUS32 has Interrupt Enable bits per level (E1/E2)
to globally enable (or disable) all IRQs at a level. Hence the
implementation of arch_local_irq_{save,restore,enable,disable}( )
The STATUS32 reg can be r/w only using the AUX Interface of ARC, hence
the use of LR/SR instructions. Further, E1/E2 bits in there can only be
updated using the FLAG insn.
The intc supports 32 interrupts - and per IRQ enabling is controlled by
a bit in the AUX_IENABLE register, hence the implmentation of
arch_{,un}mask_irq( ) routines.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Arnd in his review pointed out that arch Kconfig organisation has several
deficiencies:
* Build time entries for things which can be runtime extracted from DT
(e.g. SDRAM size, core clk frequency..)
* Not multi-platform-image-build friendly (choice .. endchoice constructs)
* cpu variants support (750/770) is exclusive.
The first 2 have been fixed in subsequent patches.
Due to the nature of the 750 and 770, it is not possible to build for
both together, w/o special runtime glue code which would hurt
performance.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Pull ARM fixes from Russell King:
"A number of fixes:
Patrik found a problem with preempt counting in the VFP assembly
functions which can cause the preempt count to be upset.
Nicolas fixed a problem with the parsing of the DT when it straddles a
1MB boundary.
Subhash Jadavani reported a problem with sparsemem and our highmem
support for cache maintanence for DMA areas, and TI found a bug in
their strongly ordered memory mapping type.
Also, three fixes by way of Will Deacon's tree from Dave Martin for
instruction compatibility and Marc Zyngier to fix hypervisor boot mode
issues."
* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
ARM: 7629/1: mm: Fix missing XN flag for for MT_MEMORY_SO
ARM: DMA: Fix struct page iterator in dma_cache_maint() to work with sparsemem
ARM: 7628/1: head.S: map one extra section for the ATAG/DTB area
ARM: 7627/1: Predicate preempt logic on PREEMP_COUNT not PREEMPT alone
ARM: virt: simplify __hyp_stub_install epilog
ARM: virt: boot secondary CPUs through the right entry point
ARM: virt: Avoid bx instruction for compatibility with <=ARMv4
Here's a long-pending fixes pull request for arm-soc (I didn't send one
in the -rc4 cycle).
The larger deltas are from:
- A fixup of error paths in the mvsdio driver
- Header file move for a driver that hadn't been properly converted to
multiplatform on i.MX, which was causing build failures when included
- Device tree updates for at91 dealing mostly with their new
pinctrl setup merged in 3.8 and mistakes in those initial configs
The rest are the normal mix of small fixes all over the place; sunxi,
omap, imx, mvebu, etc, etc.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=YDHs
-----END PGP SIGNATURE-----
Merge tag 'fixes-for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Olof Johansson:
"Here's a long-pending fixes pull request for arm-soc (I didn't send
one in the -rc4 cycle).
The larger deltas are from:
- A fixup of error paths in the mvsdio driver
- Header file move for a driver that hadn't been properly converted
to multiplatform on i.MX, which was causing build failures when
included
- Device tree updates for at91 dealing mostly with their new pinctrl
setup merged in 3.8 and mistakes in those initial configs
The rest are the normal mix of small fixes all over the place; sunxi,
omap, imx, mvebu, etc, etc."
* tag 'fixes-for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (40 commits)
mfd: vexpress-sysreg: Don't skip initialization on probe
ARM: vexpress: Enable A7 cores in V2P-CA15_A7's Device Tree
ARM: vexpress: extend the MPIDR range used for pen release check
ARM: at91/dts: correct comment in at91sam9x5.dtsi for mii
ARM: at91/at91_dt_defconfig: add at91sam9n12 SoC to DT defconfig
ARM: at91/at91_dt_defconfig: remove memory specification to cmdline
ARM: at91/dts: add macb mii pinctrl config for kizbox
ARM: at91: rm9200: remake the BGA as default version
ARM: at91: fix gpios on i2c-gpio for RM9200 DT
ARM: at91/at91sam9x5 DTS: add SCK USART pins
ARM: at91/at91sam9x5 DTS: correct wrong PIO BANK values on u(s)arts
ARM: at91/at91-pinctrl documentation: fix typo and add some details
ARM: kirkwood: fix missing #interrupt-cells property
mmc: mvsdio: use devm_ API to simplify/correct error paths.
clk: mvebu/clk-cpu.c: fix memory leakage
ARM: OMAP2+: omap4-panda: add UART2 muxing for WiLink shared transport
ARM: OMAP2+: DT node Timer iteration fix
ARM: OMAP2+: Fix section warning for omap_init_ocp2scp()
ARM: OMAP2+: fix build break for omapdrm
ARM: OMAP2: Fix missing omap2xxx_clkt_vps_late_init function calls
...
From Pawel Moll:
- makes the V2P-CA15_A7 (a.k.a. TC2) work with 3.8 kernels
- improves vexpress-sysreg.c behaviour on arm64 platforms
* 'vexpress/fixes' of git://git.linaro.org/people/pawelmoll/linux:
mfd: vexpress-sysreg: Don't skip initialization on probe
ARM: vexpress: Enable A7 cores in V2P-CA15_A7's Device Tree
ARM: vexpress: extend the MPIDR range used for pen release check
Vineet Gupta
Linus Torvalds
Olof Johansson