kernel/linux.git/arch/arc/include/asm/entry-compact.h, branch v6.6.134

ARC: entry: Add more common chores to EXCEPTION_PROLOGUE

2023-08-18T17:30:07+00:00

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 Signed-off-by: Vineet Gupta

ARC: entry: rework (non-functional)

2023-08-18T03:31:59+00:00

- comments update - rename syscall_trace_entry - use PT_xxx in entry code Signed-off-by: Vineet Gupta

ARC: entry: use gp to cache task pointer (vs. r25)

2023-08-18T03:31:59+00:00

The motivation is eventual ABI considerations for ARCv3 but even without it this change us worthwhile as diffstat reduces 100 net lines r25 is a callee saved register, normally not saved by entry code in pt_regs. However because of its usage in CONFIG_ARC_CURR_IN_REG it needs to be. This in turn requires a whole bunch of special casing when we need to access r25. Then there is distinction between user mode r25 vs. kernel mode r25 - hence distinct SAVE_CALLEE_SAVED_{USER,KERNEL} Instead use gp which is a scratch register and thus saved already in entry code. This cleans things up significantly and much nocer on eyes: - SAVE_CALLEE_SAVED_{USER,KERNEL} are now exactly same - no special user_r25 slot in pt_reggs Note that typical global asm registers are callee-saved (r25), but gp is not callee-saved thus needs additional -ffixed- toggle Signed-off-by: Vineet Gupta

ARC: Fix comment typo

2022-10-17T23:32:11+00:00

Change 'seperate' to 'separate'. Signed-off-by: Zhang Jiaming Signed-off-by: Vineet Gupta

ARC: mm: use SCRATCH_DATA0 register for caching pgdir in ARCv2 only

2021-08-24T21:25:48+00:00

MMU SCRATCH_DATA0 register is intended to cache task pgd. However in ARC700 SMP port, it has to be repurposed for re-entrant interrupt handling, while UP port doesn't. We currently handle these use-cases using a fabricated #define which has usual issues of dependency nesting and obvious ugliness. So clean this up: for ARC700 don't use to cache pgd (even in UP) and do the opposite for ARCv2. And while here, switch to canonical pgd_offset(). Acked-by: Mike Rapoport Signed-off-by: Vineet Gupta

ARC: [plat-eznps]: Drop support for EZChip NPS platform

2020-10-06T04:02:29+00:00

NPS customers are no longer doing active development, as evident from rand config build failures reported in recent times, so drop support for NPS platform. Tested-by: kernel test robot Signed-off-by: Vineet Gupta

ARCv2: mm: TLB Miss optim: SMP builds can cache pgd pointer in mmu scratch reg

2019-10-28T19:12:31+00:00

ARC700 exception (and intr handling) didn't have auto stack switching thus had to rely on stashing a reg temporarily (to free it up) at a known place in memory, allowing to code up the low level stack switching. This however was not re-entrant in SMP which thus had to repurpose the per-cpu MMU SCRATCH DATA register otherwise used to "cache" the task pdg pointer (vs. reading it from mm struct) The newer HS cores do have auto-stack switching and thus even SMP builds can use the MMU SCRATCH reg as originally intended. This patch fixes the restriction to ARC700 SMP builds only Signed-off-by: Vineet Gupta

ARC: entry: EV_Trap expects r10 (vs. r9) to have exception cause

2019-07-08T08:24:44+00:00

avoids 1 MOV instruction in light of double load/store code Signed-off-by: Vineet Gupta

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

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 Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman

ARC: [arcompact] entry.S: minor code movement

2018-07-09T18:25:45+00:00

This is a non functional code changw, which moves r25 restore from macro into the caller of macro Signed-off-by: Vineet Gupta