Caveats about cache flush on ARCv2 based cores
- dcache is PIPT so paddr is sufficient for cache maintenance ops (no
need to setup PTAG reg
- icache is still VIPT but only aliasing configs need PTAG setup
So basically this is departure from MMU-v3 which always need vaddr in
line ops registers (DC_IVDL, DC_FLDL, IC_IVIL) but paddr in DC_PTAG,
IC_PTAG respectively.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The issue was, on HS when interrupt is taken, IRQ_ACT is set and that is
NOT cleared unless we do RTIE (or manually clear it). Linux interrupt
handling has top and bottom halves. Latter lead to softirqs (which can
reschedule) AND expect interrupts to be REALLY re-enabled which was NOT
happening for us since we only SETI, dont clear IRQ_ACT
So we can have a state when both cores have taken interrupt (IRQ_ACT set),
get rescheduled, both send IPI and wait in CSD lock which will never be
cleared as cores can't take the pending IPI IRQ due to existing IRQ_ACT
set.
So local_irq_enable() now drops the IRQ_ACT.act bit to re-enable IRQs.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reported by Anton as LTP:munmap01 failing with Illegal Instruction
Exception.
--------------------->8--------------------------------------
mmap2(NULL, 24576, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) = 0x200d2000
munmap(0x200d2000, 24576) = 0
--- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x200d2000}
---
potentially unexpected fatal signal 4.
Path: /munmap01
CPU: 0 PID: 61 Comm: munmap01 Not tainted 3.13.0-g5d5c46d9a556 #8
task: 9f1a8000 ti: 9f154000 task.ti: 9f154000
[ECR ]: 0x00020100 => Illegal Insn
[EFA ]: 0x0001354c
[BLINK ]: 0x200515d4
[ERET ]: 0x1354c
@off 0x1354c in [/munmap01]
VMA: 0x00010000 to 0x00018000
[STAT32]: 0x800802c0
...
--------------------->8--------------------------------------
The issue was
1. munmap01 accessed unmapped memory (on purpose) with signal handler
installed for SIGSEGV
2. The faulting instruction happened to be in Delay Slot
00011864 <main>:
11908: bl.d 13284 <tst_resm>
1190c: stb r16,[r2]
3. kernel sets up the reg file for signal handler and correctly clears
the DE bit in pt_regs->status32 placeholder
4. However RESTORE_CALLEE_SAVED_USER macro is not adjusted for ARCv2,
and it over-writes the above with orig/stale value of status32
5. After RTIE, userspace signal handler executes a non branch
instruction with DE bit set, triggering Illegal Instruction Exception.
Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
These have been register compatible so far. However ARCv2 mandates
different pt_regs layout (due to h/w auto save). To keep pt_regs same
for both, we start by removing the assumption - used mainly for block
copies between the 2 structs in signal handling and ptrace
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Previously this macro was overloaded with stack switching, saving SP at right
slot in pt_regs, saving/setup of r25 and setting SP baseline to where
pt_regs->sp is saved (vs. bottom of pt_regs)
Now it only does SP switch, and leaves SP pointing to bottom of pt_regs.
r25 saving is no longer done here to allow for future reordering of
regfile in pt_regs w/o touching this macro
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Returning from pure kernel mode and exception mode use the same code
anyways. Remove one the duplicate blocks
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Elide the need to re-read ECR in Trap handler by ensuring that
EXCEPTION_PROLOGUE does that at the very end just before returning
to Trap handler
ARCv2 EXCEPTION_PROLOGUE already did that, so same for ARcompact and the
common trap handler adjusted to use cached ECR
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This fixes the possible link/relo errors, since restore_regs will be
provided by ISA code, but called from ARC common code.
The .L prefix reassures binutils that it will be in same compilation
unit.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
- Remove the ifdef'ery and write distinct versions for each mmu ver even
if there is some code duplication
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
That is because __after_dc_op() already reads it for status check, so it
is better anyways to use that "newer" value.
Also reduces the clutter in callers for passing from/to these routines.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
As DW Mobile Storage databook says it's required to use "Hold Register"
if card is enumerated in SDR12 or SDR25 modes.
It means we need to act in the same way as in Altera's Socfpga
implementation - set "use hold reg" bit in commad.
Note that for upstream proper solution would be to remove
dw_mci_pltfm_prepare_command() at all and set the bit right in
dw_mci_prepare_command() for all platforms.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Earlycon calculates UART clock as "BASE_BAUD * 16". In case of ARC
"BASE_BAUD" is calculated dynamically in runtime, basically it is an
alias to arc_early_base_baud(), which in turn just does
"arc_base_baud/16".
8250 UART on AXS/SDP board uses 33.3MHz clock source which is set in
"arc_base_baud" with this change.
Additional compatibility string "snps,arc-sdp" is introduced as well
because there're different flavours of AXS boards but they all share the
same motherboard and so it's possible to re-use the same code for
motherbord even if CPU daughterboard changes.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The AXS10x platforms consist of a mainboard with peripherals,
on which several daughter cards can be placed. The daughter cards
typically contain a CPU and memory.
Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Currently, it doesn't invoke the callback but continues to unwind
Also while at it - simplify the code a bit
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Directly return the result of perf_pmu_register() in
arc_pmu_device_probe() instead of assigning and returning variable ret.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
static arc_pmu in the arch/arc/kernel/perf_event.c is not initialized as
it's shadowed by a local variable of the same name in the
arc_pmu_device_probe.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Fixes: 03c94fcf95 "ARC: perf: make @arc_pmu static global"
CC: <stable@vger.kernel.org> # 4.1
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* Remove remanants of legacy ARC FPGA platforms (AA4, ML509...)
* Only nsim simulation platform is left, rename platform accordingly
* AA4 DT stuff is compatible with nsim for ARC700 so rename it too
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Back when ARC700 4.10 was released, the related kernel features were
tied to this config item so they could be disabled in one shot (i.e.
LLOCK/SCOND, SWAPE, RTSC..)
That having happened a while back, all new ARC customers weill get 4.11+
so those features can be assumed to be present and need not be tied to a
top-level (we still retain the ability to individually disable them).
Further, since ARCv2 also shares some of those feautes, removing it
simplifies things a bit in Kconfig
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC GNU tools have had support for arc-linux-* driver for some time now.
This is functionally similar to arc-linux-uclibc-* but uclibc prefix
seemed weird at best when trying to compile the kernel itself.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Two watchdog changes that came through different trees had a non
conflicting conflict, that is, one changed the semantics of a variable
but no actual code conflict happened. So the merge appeared fine, but
the resulting code did not behave as expected.
Commit 195daf665a ("watchdog: enable the new user interface of the
watchdog mechanism") changes the semantics of watchdog_user_enabled,
which thereafter is only used by the functions introduced by
b3738d2932 ("watchdog: Add watchdog enable/disable all functions").
There further appears to be a distinct lack of serialization between
setting and using watchdog_enabled, so perhaps we should wrap the
{en,dis}able_all() things in watchdog_proc_mutex.
This patch fixes a s2r failure reported by Michal; which I cannot
readily explain. But this does make the code internally consistent
again.
Reported-and-tested-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
