Commit Graph

15 Commits

Author SHA1 Message Date
Vineet Gupta
13347c1039 ARC: entry: Add more common chores to EXCEPTION_PROLOGUE
THe high level structure of most ARC exception handlers is
 1. save regfile with EXCEPTION_PROLOGUE
 2. setup r0: EFA (not part of pt_regs)
 3. setup r1: pointer to pt_regs (SP)
 4. drop down to pure kernel mode (from exception)
 5. call the Linux "C" handler

Remove the boiler plate code by moving #2, #3, #4 into #1.

The exceptions to most exceptions are syscall Trap and Machine check
which don't do some of above for various reasons, so call a newly
introduced variant EXCEPTION_PROLOGUE_KEEP_AE (same as original
EXCEPTION_PROLOGUE)

Tested-by: Pavel Kozlov <Pavel.Kozlov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2023-08-18 10:30:07 -07:00
Vineet Gupta
6b606c8d66 ARC: entry: ARcompact EV_ProtV to use r10 directly
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2023-08-17 20:31:59 -07:00
Vineet Gupta
68e5c6f073 ARC: entry: EV_Trap expects r10 (vs. r9) to have exception cause
avoids 1 MOV instruction in light of double load/store code

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-07-08 09:24:44 +01:00
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Liav Rehana
9405530469 ARC: typos fix in kernel/entry-compact.S
Signed-off-by: Liav Rehana <liavr@mellanox.com>
Signed-off-by: Noam Camus <noamca@mellanox.com>
Reviewed-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-08-28 15:17:36 -07:00
Vineet Gupta
f5f3bde4f6 ARC: ARCompact entry: elide re-reading ECR in ProtV handler
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-12-13 13:16:11 -08:00
Vineet Gupta
60f2b4b8af ARC: [intc-compact] simplify code for 2 priority levels
ARC700 support for 2 interrupt priorities historically allowed even slow
perpherals such as emac and uart to setup high priority interrupts
which was wrong from the beginning as they could possibly delay the more
critical timer interrupt.

The hardware support for 2 level interrupts in ARCompact is less than
ideal anyways (judging from the "hacks" in low level entry code and thus
is not used in productions systems I know of.

So reduce the scope of this to timer only, thereby reducing a bunch of
complexity.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-05-30 22:45:04 +05:30
Evgeny Voevodin
d9676fa152 ARCv2: Enable LOCKDEP
- The asm helpers for calling into irq tracer were missing

- Add calls to above helpers in low level assembly entry code for ARCv2

- irq_save() uses CLRI to disable interrupts and returns the prev interrupt
  state (in STATUS32) in a specific encoding (and not the raw value of
  STATUS32). This is usable with SETI in irq_restore(). However
  save_flags() reads the raw value of STATUS32 which doesn't pair with
  irq_save/restore() and thus needs fixing.

Signed-off-by: Evgeny Voevodin <evgeny.voevodin@intel.com>
[vgupta: updated changelog and also added some comments]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-04-22 18:12:31 +05:30
Vineet Gupta
541366da6a ARC: [arcompact] Handle bus error from userspace as Interrupt not exception
Bus errors from userspace on ARCompact based cores are handled by core
as a high priority L2 interrupt but current code treated it as interrupt
Handling an interrupt like exception is certainly not going to go unnoticed.
(and it worked so far as we never saw a Bus error from userspace until
IPPK guys tested a DDR controller with ECC error detection etc hence
needed to explicitly trigger/handle such errors)

 - So move mem_service exception handler from common code into ARCv2 code.
 - In ARCompact code, define  mem_service as L2 interrupt handler which
   just drops down to pure kernel mode and goes of to enqueue SIGBUS

Reported-by: Nelson Pereira <npereira@synopsys.com>
Tested-by: Ana Martins <amartins@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-14 13:12:20 +05:30
Vineet Gupta
3971cdc202 ARC: boot: Support Halt-on-reset and Run-on-reset SMP booting modes
For Run-on-reset, non masters need to spin wait. For Halt-on-reset they
can jump to entry point directly.

Also while at it, made reset vector handler as "the" entry point for
kernel including host debugger based boot (which uses the ELF header
entry point)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:08:17 +05:30
Vineet Gupta
9fabcc636b ARC: [arcompact] entry.S: Elide extra check/branch in exception ret path
This is done by improving the laddering logic !

Before:

   if Exception
      goto excep_or_pure_k_ret

   if !Interrupt(L2)
      goto l1_chk
   else
      INTERRUPT_EPILOGUE 2

 l1_chk:
   if !Interrupt(L1)  (i.e. pure kernel mode)
      goto excep_or_pure_k_ret
   else
      INTERRUPT_EPILOGUE 1

 excep_or_pure_k_ret:
   EXCEPTION_EPILOGUE

Now:

   if !Interrupt(L1 or L2) (i.e. exception or pure kernel mode)
      goto excep_or_pure_k_ret

  ; guaranteed to be an interrupt
   if !Interrupt(L2)
      goto l1_ret
   else
      INTERRUPT_EPILOGUE 2

 ; by virtue of above, no need to chk for L1 active
 l1_ret:
    INTERRUPT_EPILOGUE 1

 excep_or_pure_k_ret:
    EXCEPTION_EPILOGUE

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:23 +05:30
Vineet Gupta
5f88808745 ARC: [arcompact] entry.S: Document preemption games for L2 intr
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:23 +05:30
Vineet Gupta
c80417b612 ARC: entry.S: use single EXCEPTION_PROLOGUE
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>
2015-06-19 18:09:39 +05:30
Vineet Gupta
c7e6d79204 ARC: entry.S: move some code around for cache locality in return path
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:38 +05:30
Vineet Gupta
6d1a20b1d2 ARC: entry.S: split into ARCompact ISA specific, common bits
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:38 +05:30