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authorLinus Torvalds <torvalds@linux-foundation.org>2023-09-04 15:38:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-09-04 15:38:24 -0700
commit3f86ed6ec0b390c033eae7f9c487a3fea268e027 (patch)
treea0a1fa3e5c04e146bf9414833da9bc634df10b95 /arch/arc/kernel/ctx_sw.c
parentea4f9c37f75271d8256a326c938c95733e1fec35 (diff)
parentc40cad3b0aa47d6d0995637178fb6607ac3d45c1 (diff)
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Merge tag 'arc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC updates from Vineet Gupta: - fixes for -Wmissing-prototype warnings - missing compiler barrier in relaxed atomics - some uaccess simplification, declutter - removal of massive glocal struct cpuinfo_arc from bootlog code - __switch_to consolidation (removal of inline asm variant) - use GP to cache task pointer (vs. r25) - misc rework of entry code * tag 'arc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (24 commits) ARC: boot log: fix warning arc: Explicitly include correct DT includes ARC: pt_regs: create seperate type for ecr ARCv2: entry: rearrange pt_regs slightly ARC: entry: replace 8 byte ADD.ne with 4 byte ADD2.ne ARC: entry: replace 8 byte OR with 4 byte BSET ARC: entry: Add more common chores to EXCEPTION_PROLOGUE ARC: entry: EV_MachineCheck dont re-read ECR ARC: entry: ARcompact EV_ProtV to use r10 directly ARC: entry: rework (non-functional) ARC: __switch_to: move ksp to thread_info from thread_struct ARC: __switch_to: asm with dwarf ops (vs. inline asm) ARC: kernel stack: INIT_THREAD need not setup @init_stack in @ksp ARC: entry: use gp to cache task pointer (vs. r25) ARC: boot log: eliminate struct cpuinfo_arc #4: boot log per ISA ARC: boot log: eliminate struct cpuinfo_arc #3: don't export ARC: boot log: eliminate struct cpuinfo_arc #2: cache ARC: boot log: eliminate struct cpuinfo_arc #1: mm ARCv2: memset: don't prefetch for len == 0 which happens a alot ARC: uaccess: elide unaliged handling if hardware supports ...
Diffstat (limited to 'arch/arc/kernel/ctx_sw.c')
-rw-r--r--arch/arc/kernel/ctx_sw.c112
1 files changed, 0 insertions, 112 deletions
diff --git a/arch/arc/kernel/ctx_sw.c b/arch/arc/kernel/ctx_sw.c
deleted file mode 100644
index 1a76f2d6f694..000000000000
--- a/arch/arc/kernel/ctx_sw.c
+++ /dev/null
@@ -1,112 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
- *
- * Vineetg: Aug 2009
- * -"C" version of lowest level context switch asm macro called by schedular
- * gcc doesn't generate the dward CFI info for hand written asm, hence can't
- * backtrace out of it (e.g. tasks sleeping in kernel).
- * So we cheat a bit by writing almost similar code in inline-asm.
- * -This is a hacky way of doing things, but there is no other simple way.
- * I don't want/intend to extend unwinding code to understand raw asm
- */
-
-#include <asm/asm-offsets.h>
-#include <linux/sched.h>
-#include <linux/sched/debug.h>
-
-#define KSP_WORD_OFF ((TASK_THREAD + THREAD_KSP) / 4)
-
-struct task_struct *__sched
-__switch_to(struct task_struct *prev_task, struct task_struct *next_task)
-{
- unsigned int tmp;
- unsigned int prev = (unsigned int)prev_task;
- unsigned int next = (unsigned int)next_task;
-
- __asm__ __volatile__(
- /* FP/BLINK save generated by gcc (standard function prologue */
- "st.a r13, [sp, -4] \n\t"
- "st.a r14, [sp, -4] \n\t"
- "st.a r15, [sp, -4] \n\t"
- "st.a r16, [sp, -4] \n\t"
- "st.a r17, [sp, -4] \n\t"
- "st.a r18, [sp, -4] \n\t"
- "st.a r19, [sp, -4] \n\t"
- "st.a r20, [sp, -4] \n\t"
- "st.a r21, [sp, -4] \n\t"
- "st.a r22, [sp, -4] \n\t"
- "st.a r23, [sp, -4] \n\t"
- "st.a r24, [sp, -4] \n\t"
-#ifndef CONFIG_ARC_CURR_IN_REG
- "st.a r25, [sp, -4] \n\t"
-#else
- "sub sp, sp, 4 \n\t" /* usual r25 placeholder */
-#endif
-
- /* set ksp of outgoing task in tsk->thread.ksp */
-#if KSP_WORD_OFF <= 255
- "st.as sp, [%3, %1] \n\t"
-#else
- /*
- * Workaround for NR_CPUS=4k
- * %1 is bigger than 255 (S9 offset for st.as)
- */
- "add2 r24, %3, %1 \n\t"
- "st sp, [r24] \n\t"
-#endif
-
- /*
- * setup _current_task with incoming tsk.
- * optionally, set r25 to that as well
- * For SMP extra work to get to &_current_task[cpu]
- * (open coded SET_CURR_TASK_ON_CPU)
- */
-#ifndef CONFIG_SMP
- "st %2, [@_current_task] \n\t"
-#else
- "lr r24, [identity] \n\t"
- "lsr r24, r24, 8 \n\t"
- "bmsk r24, r24, 7 \n\t"
- "add2 r24, @_current_task, r24 \n\t"
- "st %2, [r24] \n\t"
-#endif
-#ifdef CONFIG_ARC_CURR_IN_REG
- "mov r25, %2 \n\t"
-#endif
-
- /* get ksp of incoming task from tsk->thread.ksp */
- "ld.as sp, [%2, %1] \n\t"
-
- /* start loading it's CALLEE reg file */
-
-#ifndef CONFIG_ARC_CURR_IN_REG
- "ld.ab r25, [sp, 4] \n\t"
-#else
- "add sp, sp, 4 \n\t"
-#endif
- "ld.ab r24, [sp, 4] \n\t"
- "ld.ab r23, [sp, 4] \n\t"
- "ld.ab r22, [sp, 4] \n\t"
- "ld.ab r21, [sp, 4] \n\t"
- "ld.ab r20, [sp, 4] \n\t"
- "ld.ab r19, [sp, 4] \n\t"
- "ld.ab r18, [sp, 4] \n\t"
- "ld.ab r17, [sp, 4] \n\t"
- "ld.ab r16, [sp, 4] \n\t"
- "ld.ab r15, [sp, 4] \n\t"
- "ld.ab r14, [sp, 4] \n\t"
- "ld.ab r13, [sp, 4] \n\t"
-
- /* last (ret value) = prev : although for ARC it mov r0, r0 */
- "mov %0, %3 \n\t"
-
- /* FP/BLINK restore generated by gcc (standard func epilogue */
-
- : "=r"(tmp)
- : "n"(KSP_WORD_OFF), "r"(next), "r"(prev)
- : "blink"
- );
-
- return (struct task_struct *)tmp;
-}