kernel/linux.git/arch/arc/include/asm/entry.h, branch v6.12.80

ARC: Fix typos

2024-04-02T01:40:39+00:00

Fix typos, most reported by "codespell arch/arc". Only touches comments, no code changes. Signed-off-by: Bjorn Helgaas Signed-off-by: Vineet Gupta

ARC: entry: move ARCompact specific bits out of entry.h

2023-12-09T00:30:24+00:00

- PUSHAUX/POPAUX helpers to ARCompact entry - use gas provided "push"/pop pseudo instructions Signed-off-by: Vineet Gupta

ARC: entry: SAVE_ABI_CALLEE_REG: ISA/ABI specific helper

2023-12-09T00:30:24+00:00

And for ARcompact variant replace the PUSH/POP macros with gas provided push/pop pseudo-instructions This allows ISA specific implementation e.g. Current ARCv2 PUSH/POP could be replaced with STD/LDL to save 2 registers at a time (w/o bothering with SP update each time) or perhaps use ENTER_S/LEAVE_S to reduce code size For ARCv3 ABI changed so callee regs are now r14-r26 (vs. r13-r25) thus would need a different implementation. 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: -Wmissing-prototype warning fixes

2023-08-13T23:53:02+00:00

Anrd reported [1] new compiler warnings due to -Wmissing-protype. These are for non static functions mostly used in asm code hence not exported already. Fix this by adding the prototypes. [1] https://lore.kernel.org/lkml/20230810141947.1236730-1-arnd@kernel.org Reviewed-by: Arnd Bergmann 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

ARC: use correct offset in pt_regs for saving/restoring user mode r25

2016-08-19T17:44:13+00:00

User mode callee regs are explicitly collected before signal delivery or breakpoint trap. r25 is special for kernel as it serves as task pointer, so user mode value is clobbered very early. It is saved in pt_regs where generally only scratch (aka caller saved) regs are saved. The code to access the corresponding pt_regs location had a subtle bug as it was using load/store with scaling of offset, whereas the offset was already byte wise correct. So fix this by replacing LD.AS with a standard LD Cc: Signed-off-by: Liav Rehana Reviewed-by: Alexey Brodkin [vgupta: rewrote title and commit log] Signed-off-by: Vineet Gupta

ARCv2: STAR 9000808988: signals involving Delay Slot

2015-06-22T08:36:55+00:00

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

: 11908: bl.d 13284 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 Signed-off-by: Vineet Gupta

ARCv2: Support for ARCv2 ISA and HS38x cores

2015-06-22T08:36:55+00:00

The notable features are: - SMP configurations of upto 4 cores with coherency - Optional L2 Cache and IO-Coherency - Revised Interrupt Architecture (multiple priorites, reg banks, auto stack switch, auto regfile save/restore) - MMUv4 (PIPT dcache, Huge Pages) - Instructions for * 64bit load/store: LDD, STD * Hardware assisted divide/remainder: DIV, REM * Function prologue/epilogue: ENTER_S, LEAVE_S * IRQ enable/disable: CLRI, SETI * pop count: FFS, FLS * SETcc, BMSKN, XBFU... Signed-off-by: Vineet Gupta