asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.
auto-generated by the following:
for i in `git grep -l -w asm/unaligned.h`; do
sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
Declarations local to arch/*/kernel/*.c are better off *not* in a public
header - arch/arc/kernel/unaligned.h is just fine for those
bits.
Unlike the parisc case, here we have an extra twist - asm/mmu.h
has an implicit dependency on struct pt_regs, and in some users
that used to be satisfied by include of asm/ptrace.h from
asm/unaligned.h (note that asm/mmu.h itself did _not_ pull asm/unaligned.h
- it relied upon the users having pulled asm/unaligned.h before asm/mmu.h
got there).
Seeing that asm/mmu.h only wants struct pt_regs * arguments in
an extern, just pre-declare it there - less brittle that way.
With that done _all_ asm/unaligned.h instances are reduced to include
of asm-generic/unaligned.h and can be removed - unaligned.h is in
mandatory-y in include/asm-generic/Kbuild.
What's more, we can move asm-generic/unaligned.h to linux/unaligned.h
and switch includes of <asm/unaligned.h> to <linux/unaligned.h>; that's
better off as an auto-generated commit, though, to be done by Linus
at -rc1 time next cycle.
Acked-by: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The uapi/asm/unistd_32.h and asm/syscall_table_32.h headers can now be
generated from scripts/syscall.tbl, which makes this consistent with
the other architectures that have their own syscall.tbl.
arc has a couple of architecture specific system calls, which I add to the
generic table. This for some reason includes the deprecated sys_sysfs()
syscall that was presumably added by accident.
The time32, renameat, stat64 and rlimit entries in the syscall_abis_32
entry are for system calls that were part of the generic ABI when arch/arc
got added but are no longer enabled by default for new architectures.
Both the user visible side of asm/unistd.h and the internal syscall
table in the kernel should have the same effective contents after this.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
There is no point in having seven architectures implementing the same empty
stub.
Provide a weak function in the init code and remove the stubs.
This also allows to utilize the function on UP which is required to
sanitize the per CPU handling on X86 UP.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240304005104.567671691@linutronix.de
Overlayfs uses backing files with "fake" overlayfs f_path and "real"
underlying f_inode, in order to use underlying inode aops for mapped
files and to display the overlayfs path in /proc/<pid>/maps.
In preparation for storing the overlayfs "fake" path instead of the
underlying "real" path in struct backing_file, define a noop helper
file_user_path() that returns f_path for now.
Use the new helper in procfs and kernel logs whenever a path of a
mapped file is displayed to users.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231009153712.1566422-3-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Instead of r26,fp,sp,r12,r30 order as fp,r30,r12,r26,sp
- keeps SP at well known position (right abive hardware autosave)
- r26,r12 saved specifically for ARCv2 (and not in ARCv3) kept
closer for easy ifdef'ry later
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
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>
task's arch specific bits are carried in 2 places
- embedded thread_struct in task_struct
- associated thread_info (hoisted in task's stack page) and
syntactically: (thread_info *)(task_struct->stack)
ksp (dynamic kernel stack top) currently lives in thread_struct but
given its deep location in task struct likely to cache miss when
accessed from __switch_to(). Moving it to thread_info would be more
efficient given proximity to frequently accessed items such as
preempt_count thus very likely to be in cache, specially in schedular
code.
Note however that currently tsk.thread.ksp takes 1 memory access (off
of tsk pointer) while new code tsk->stack.ksp would take 2, but likely
to be in cache. Moreover if task is current the 2nd reference can be
elided and instead derived from SP as (SP & ~(THREAD_SIZE - 1))
All of this also makes __switch_to() code simpler and we can see the 2
ways of retirving ksp (descrobed above) in new code.
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
__switch_to() is final step of context switch, swapping kernel modes
stack (and callee regs) of outgoing task with next task.
It is also the starting point of stack unwinging of a sleeping task and
captures SP, FP, BLINK and the corresponding dwarf info. Back when
dinosaurs still roamed around, ARC gas didn't support CFI pseudo ops and
gcc was responsible for generating dwarf info. Thus it had to be written
in "C" with inline asm to do the hand crafting of stack. The function
prologue (and crucial saving of blink etc) was still gcc generated but
not visible in code. Likewise dwarf info was missing.
Now with modern tools, we can make things more obvious by writing the
code in asm and adding approproate dwarf cfi pseudo ops.
This is mostly non functional change, except for slight chnages to asm
- ARCompact doesn't support MOV_S fp, sp, so we use MOV
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
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-<reg> toggle
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
This is first step in eliminating struct cpuinfo_arc[NR_CPUS]
Back when we had just ARCompact ISA, the idea was to read/bit-fiddle
the BCRs once and and cache decoded information in a global struct ready
to use.
With ARCv2 it was modified to contained abstract / ISA agnostic
information.
However with ARCv3 there 's too much disparity to abstract in common
structures. So drop the entire decode once and store paradigm. Afterall
there's only 2 users of this machinery anyways: boot printing and
cat /proc/cpuinfo. None is performance critical to warrant locking away
resident memory per cpu.
This patch is first step in that direction
- decouples struct cpuinfo_arc_mmu from global struct cpuinfo_arc
- mmu code still has a trimmed down static version of
struct cpuinfo_arc_mmu to cache information needed in performance
critical code such as tlb flush routines
- folds read_decode_mmu_bcr() into arc_mmu_mumbojumbo()
- setup_processor() directly calls arc_mmu_init() and not via
arc_cpu_init()
Tested-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308151213.qKZPMiyz-lkp@intel.com/
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
Pull SMP cross-CPU function-call updates from Ingo Molnar:
- Remove diagnostics and adjust config for CSD lock diagnostics
- Add a generic IPI-sending tracepoint, as currently there's no easy
way to instrument IPI origins: it's arch dependent and for some major
architectures it's not even consistently available.
* tag 'smp-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
trace,smp: Trace all smp_function_call*() invocations
trace: Add trace_ipi_send_cpu()
sched, smp: Trace smp callback causing an IPI
smp: reword smp call IPI comment
treewide: Trace IPIs sent via smp_send_reschedule()
irq_work: Trace self-IPIs sent via arch_irq_work_raise()
smp: Trace IPIs sent via arch_send_call_function_ipi_mask()
sched, smp: Trace IPIs sent via send_call_function_single_ipi()
trace: Add trace_ipi_send_cpumask()
kernel/smp: Make csdlock_debug= resettable
locking/csd_lock: Remove per-CPU data indirection from CSD lock debugging
locking/csd_lock: Remove added data from CSD lock debugging
locking/csd_lock: Add Kconfig option for csd_debug default
