C-SKY MMU would pre-fetch invalid pte entries, and it could work with
flush_tlb_fix_spurious_fault, but the additional page fault exceptions
would reduce performance. So flushing the entry of the TLB would prevent
the following spurious page faults. Here is the test code:
define DATA_LEN 4096
define COPY_NUM (504*100)
unsigned char src[DATA_LEN*COPY_NUM] = {0};
unsigned char dst[DATA_LEN*COPY_NUM] = {0};
unsigned char func_src[DATA_LEN*COPY_NUM] = {0};
unsigned char func_dst[DATA_LEN*COPY_NUM] = {0};
void main(void)
{
int j;
for (j = 0; j < COPY_NUM; j++)
memcpy(&dst[j*DATA_LEN], &src[j*DATA_LEN], 4);
}
perf stat -e page-faults ./main.elf
The amount of page fault traps would be reduced in half with the patch.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the
offset. This reduces the maximum swap space per file to 16 GiB (was 32
GiB).
We might actually be able to reuse one of the other software bits
(_PAGE_READ / PAGE_WRITE) instead, because we only have to keep
pte_present(), pte_none() and HW happy. For now, let's keep it simple
because there might be something non-obvious.
Link: https://lkml.kernel.org/r/20230113171026.582290-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Guo Ren <guoren@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Try to access RAM with the largest bit width possible, but without
doing unaligned accesses.
A further improvement could be to use multiple read and writes as the
assembly version was trying to do.
Tested on a BeagleV Starlight with a SiFive U74 core, where the
improvement is noticeable.
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Co-developed-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
: error: C++ style comments are not allowed in ISO C90
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
^
error: (this will be reported only once per input file)
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
It could help to reduce the latency of the time-related functions
in user space.
We have referenced arm's and riscv's implementation for the patch.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Vincent Chen <vincent.chen@sifive.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Current csky's swappon is broken by wrong swap PTE entry format.
Now redesign the new format for abiv1 & abiv2 and make swappon +
zram work properly on csky machines.
C-SKY PTE has VALID, DIRTY to emulate PRESENT, READ, WRITE, EXEC
attributes. GLOBAL bit is shared by two pages in the same tlb
entry. So we need to keep GLOBAL, VALID, PRESENT zero in swp_pte.
To distinguish PAGE_NONE and swp_pte, we need to use an additional
bit (abiv1 is _PAGE_READ, abiv2 is _PAGE_WRITE).
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Reconstruct vdso framework to support future vsyscall,
vgettimeofday features. These are very important features to reduce
system calls into the kernel for performance improvement.
The patch is reference RISC-V's
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
The function update_mmu_cache could be called by user-io mapping.
There is no space of struct page in mem_map for the pte. Just
ignore the user-io mmaping in update_mmu_cache.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
TLB invalidate didn't contain a barrier operation in csky cpu and
we need to prevent previous PTW response after TLB invalidation
instruction. Of cause, the ASID changing also needs to take care
of the issue.
CPU0 CPU1
=============== ===============
set_pte
sync_is() -> See the previous set_pte for all harts
tlbi.vas -> Invalidate all harts TLB entry & flush pipeline
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
There are two ways for translating va to pa for csky:
- Use TLB(Translate Lookup Buffer) and PTW (Page Table Walk)
- Use SSEG0/1 (Simple Segment Mapping)
We use tlb mapping 0-2G and 3G-4G virtual address area and SSEG0/1
are for 2G-2.5G and 2.5G-3G translation. We could disable SSEG0
to use 2G-2.5G as TLB user mapping.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
The "Changing Execution Path" section in the Documentation/kprobes.txt
said:
Since kprobes can probe into a running kernel code, it can change the
register set, including instruction pointer.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
There is no user return for RESTORE_REGS_FTRACE, so it's no need to
save sp into ss0 as RESTORE_REGS_ALL.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
There is no fixup or feature in the patch, we only cleanup with:
- Remove unnecessary reg used (r11, r12), just use r9 & r10 &
syscallid regs as temp useage.
- Add _TIF_SYSCALL_WORK and _TIF_WORK_MASK to gather macros.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Current implementation could destory a4 & a5 when strace, so we need to get them
from pt_regs by SAVE_ALL.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Just as comment mentioned, the msa format:
cr<30/31, 15> MSA register format:
31 - 29 | 28 - 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
BA Reserved SH WA B SO SEC C D V
So we should shift 29 bits not 28 bits for mask
Signed-off-by: Liu Yibin <jiulong@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
When CONFIG_DYNAMIC_FTRACE is enabled, static ftrace will fail to
boot up and compile. It's a carelessness when developing "dynamic
ftrace" and "ftrace with regs".
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
For the memory size ( > 512MB, < 1GB), the MSA setting is:
- SSEG0: PHY_START , PHY_START + 512MB
- SSEG1: PHY_START + 512MB, PHY_START + 1GB
But the real memory is no more than 1GB, there is a gap between the
end size of memory and border of 1GB. CPU could speculatively
execute to that gap and if the gap of the bus couldn't respond to
the CPU request, then the crash will happen.
Now make the setting with:
- SSEG0: PHY_START , PHY_START + 512MB (no change)
- SSEG1: Disabled (We use highmem to use the memory of 512MB~1GB)
We also deprecated zhole_szie[] settings, it's only used by arm
style CPUs. All memory gap should use Reserved setting of dts in
csky system.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
This patch implements FTRACE_WITH_REGS for csky, which allows a traced
function's arguments (and some other registers) to be captured into a
struct pt_regs, allowing these to be inspected and/or modified.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
WARNING: vmlinux.o(.text+0x2366): Section mismatch in reference from the
function csky_start_secondary() to the function .init.text:init_fpu()
The function csky_start_secondary() references
the function __init init_fpu().
This is often because csky_start_secondary lacks a __init
annotation or the annotation of init_fpu is wrong.
Reported-by: Lu Chongzhi <chongzhi.lcz@alibaba-inc.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Some CPUs don't support icache.va instruction to maintain the whole
smp cores' icache. Using icache.all + IPI casue a lot on performace
and using defer mechanism could reduce the number of calling icache
_flush_all functions.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Only when vma is for VM_EXEC, we need sync dcache & icache. eg:
- gdb ptrace modify user space instruction code area.
Add VM_EXEC condition to reduce unnecessary cache flush.
The abiv1 cpus' cache are all VIPT, so we still need to deal with
dcache aliasing problem. But there is optimized way to use cache
color, just like what's done in arch/csky/abiv1/inc/abi/page.h.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Instead of flushing cache per update_mmu_cache() called, we use
flush_dcache_page to reduce the frequency of flashing the cache.
As abiv2 cpus are all PIPT for icache & dcache, we needn't handle
dcache aliasing problem. But their icache can't snoop dcache, so
we still need sync_icache_dcache in update_mmu_cache().
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
The abiv2 CPUs are all PIPT cache, so there is no need to implement
flush_icache_page function.
The function flush_icache_user_range hasn't been used, so just
remove it.
The function flush_cache_range is not necessary for PIPT cache when
tlb mapping changed.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
In the past, we didn't care about kernel sp when saving pt_reg. But in some
cases, we still need pt_reg->usp to represent the kernel stack before enter
exception.
For cmpxhg in atomic.S, we need save and restore usp for above.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
This round of csky subsystem gives two features (ASID algorithm update,
Perf pmu record support) and some fixups.
Feature:
- csky: Revert mmu ASID mechanism
- csky: Add new asid lib code from arm
- csky: Use generic asid algorithm to implement switch_mm
- csky: Improve tlb operation with help of asid
- csky: Init pmu as a device
- csky: Add count-width property for csky pmu
- csky: Add pmu interrupt support
- csky: Fix perf record in kernel/user space
- dt-bindings: csky: Add csky PMU bindings
Fixup:
- csky: Fixup no panic in kernel for some traps
- csky: Fixup some error count in 810 & 860.
- csky: Fixup abiv1 memset error
CI-Tested: https://gitlab.com/c-sky/buildroot/pipelines/68656845
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Merge tag 'csky-for-linus-5.3-rc1' of git://github.com/c-sky/csky-linux
Pull arch/csky pupdates from Guo Ren:
"This round of csky subsystem gives two features (ASID algorithm
update, Perf pmu record support) and some fixups.
ASID updates:
- Revert mmu ASID mechanism
- Add new asid lib code from arm
- Use generic asid algorithm to implement switch_mm
- Improve tlb operation with help of asid
Perf pmu record support:
- Init pmu as a device
- Add count-width property for csky pmu
- Add pmu interrupt support
- Fix perf record in kernel/user space
- dt-bindings: Add csky PMU bindings
Fixes:
- Fixup no panic in kernel for some traps
- Fixup some error count in 810 & 860.
- Fixup abiv1 memset error"
* tag 'csky-for-linus-5.3-rc1' of git://github.com/c-sky/csky-linux:
csky: Fixup abiv1 memset error
csky: Improve tlb operation with help of asid
csky: Use generic asid algorithm to implement switch_mm
csky: Add new asid lib code from arm
csky: Revert mmu ASID mechanism
dt-bindings: csky: Add csky PMU bindings
dt-bindings: interrupt-controller: Update csky mpintc
csky: Fixup some error count in 810 & 860.
csky: Fix perf record in kernel/user space
csky: Add pmu interrupt support
csky: Add count-width property for csky pmu
csky: Init pmu as a device
csky: Fixup no panic in kernel for some traps
csky: Select intc & timer drivers
Use linux generic asid/vmid algorithm to implement csky
switch_mm function. The algorithm is from arm and it could
work with SMP system. It'll help reduce tlb flush for
switch_mm in task/vm switch.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Pull force_sig() argument change from Eric Biederman:
"A source of error over the years has been that force_sig has taken a
task parameter when it is only safe to use force_sig with the current
task.
The force_sig function is built for delivering synchronous signals
such as SIGSEGV where the userspace application caused a synchronous
fault (such as a page fault) and the kernel responded with a signal.
Because the name force_sig does not make this clear, and because the
force_sig takes a task parameter the function force_sig has been
abused for sending other kinds of signals over the years. Slowly those
have been fixed when the oopses have been tracked down.
This set of changes fixes the remaining abusers of force_sig and
carefully rips out the task parameter from force_sig and friends
making this kind of error almost impossible in the future"
* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
signal: Remove the signal number and task parameters from force_sig_info
signal: Factor force_sig_info_to_task out of force_sig_info
signal: Generate the siginfo in force_sig
signal: Move the computation of force into send_signal and correct it.
signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
signal: Remove the task parameter from force_sig_fault
signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
signal: Explicitly call force_sig_fault on current
signal/unicore32: Remove tsk parameter from __do_user_fault
signal/arm: Remove tsk parameter from __do_user_fault
signal/arm: Remove tsk parameter from ptrace_break
signal/nds32: Remove tsk parameter from send_sigtrap
signal/riscv: Remove tsk parameter from do_trap
signal/sh: Remove tsk parameter from force_sig_info_fault
signal/um: Remove task parameter from send_sigtrap
signal/x86: Remove task parameter from send_sigtrap
signal: Remove task parameter from force_sig_mceerr
signal: Remove task parameter from force_sig
signal: Remove task parameter from force_sigsegv
...
As synchronous exceptions really only make sense against the current
task (otherwise how are you synchronous) remove the task parameter
from from force_sig_fault to make it explicit that is what is going
on.
The two known exceptions that deliver a synchronous exception to a
stopped ptraced task have already been changed to
force_sig_fault_to_task.
The callers have been changed with the following emacs regular expression
(with obvious variations on the architectures that take more arguments)
to avoid typos:
force_sig_fault[(]\([^,]+\)[,]\([^,]+\)[,]\([^,]+\)[,]\W+current[)]
->
force_sig_fault(\1,\2,\3)
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The name of phys_offset is so common for global export and it may
conflict with some local name. So change phys_offset to va_pa_offset
which also used by riscv.
Also use __pa() and __va() instead of using phys_offset directly.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Modify SETUP_MMU macro to fit on both MMU-on or MMU-off enviornment
and vmlinux could bootup from MMU off enviornment for some cases.
Unify the style of _start and _start_smp_secondary in head.S to make
head.S looks more concise and easy to understand.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
In trace events as tracepoints context are not able to
be retrieve with task_pt_regs. Without arch caller regs
support the pt_regs context will be all zero, perf can
not parsing the callchain and resolving the symbols
correctly, some time will even get into deadlock
while handling the page fault, eg:
perf kmem —page record ls
Changelog
- Add test case cmd in comment
- Use regs_fp(regs) which is defined in abi/regdef.h
Signed-off-by: Mao Han <han_mao@c-sky.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
In our stress test, we found some crash problem caused by:
if (!(vma->vm_flags & VM_EXEC))
return;
in update_mmu_cache().
Seems current update_mmu_cache implementation is wrong and we retread
to the conservative implementation.
Also the usage of kmap_atomic in update_mmu_cache is risky, page-virtual
may be scheduled out and changed, so we must use preempt_disable &
pagefault_disable which is called by kmap_atomic().
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Before this patch csky-linux need CONFIG_RAM_BASE to determine start
physical address. Now we use phys_offset variable to replace the macro
of PHYS_OFFSET and we setup phys_offset with real physical address which
is determined during startup in head.S.
With this patch we needn't re-compile kernel for different start
physical address. ie: 0x0 / 0xc0000000 start physical address could use
the same vmlinux, be care different start address must be 512MB aligned.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Linux kernel has provided some apis for arch signal's implementation.
For example:
restore_saved_sigmask()
set_current_blocked()
restore_altstack()
But in last version of csky signal.c didn't use them and some codes are
confusing, so reconstruct signal.c with reference to riscv's code.
Now csky signal.c implementation are very close to riscv and we can
get the following benefits:
- Clear code structure
- The signal code of riscv and csky can be reviewed together
- Promoting the unification of arch's signal implementation
Also modified the related code in entry.S
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
We could use regs->sr 16-24 bits to detect syscall: VEC_TRAP0 and
r11_sig is no necessary for current implementation.
In this patch, we implement the in_syscall and forget_syscall which are
inspired from arm & nds32, but csky pt_regs has no syscall_num element
and we just set zero to regs->sr's vector-bits-field instead.
For ret_from_fork, current task was forked from parent which is in syscall
progress and its regs->sr has been already setted with VEC_TRAP0. See:
arch/csky/kernel/process.c: copy_thread()
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Previous syscall_trace implementation couldn't support AUDITSYSCALL and
SYSCALL_TRACEPOINTS. Now we redesign it to support audit_syscall
and syscall_tracepoints just like other archs'.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Dmitry V. Levin <ldv@altlinux.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Support dynamic ftrace including dynamic graph tracer. Gcc-csky with -pg
will produce call site in every function prologue and we can use these
call site to hook trace function.
gcc with -pg origin call site:
push lr
jbsr _mcount
nop32
nop32
If the (callee - caller)'s offset is in range of bsr instruction, we'll
modify code with:
push lr
bsr _mcount
nop32
nop32
Else if the (callee - caller)'s offset is out of bsr instrunction, we'll
modify code with:
push lr
movih r26, ...
ori r26, ...
jsr r26
(r26 is reserved for jsr link reg in csky abiv2 spec.)
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
This fixup is continue to commit 35ff802af1 (csky: fixup remove
vdsp implement for kernel.) and in that patch I didn't finish the
job. We must forbid gcc to generate any vdsp & fpu instructions
and remove vdsp asm in memmove.S.
eg: For GCC it's -mcpu=ck860 and For AS it's -Wa,-mcpu=ck860fv
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
When gcc with -pg, it'll add _mcount stub in every function. We need
implement the _mcount in kernel and ftrace depends on stackstrace.
To do: call-graph, dynamic ftrace
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
HI, LO, DSPCR registers are 807/810 related regs and no need for 610/860.
All of the regs must be saved in pt_regs and switch_stack. This patch
fixup saving dspcr reg in switch_stack and pt_regs.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
The vr regs for vdsp only saved in task_switch not in every
exception trap-in. The memcpy with vdsp instructions will
destroy the vr regs for user space applications.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Glibc function mmap(... O_SYNC) will make page to _PAGE_UNCACHE +
_PAGE_SO and strong-order page couldn't support unalignment access.
So remove _PAGE_SO from _PAGE_UNCACHE, also sync abiv1 with the macro
of _PAGE_SO.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reported-by: Liu Renwei <Renwei.Liu@verisilicon.com>
Tested-by: Yuan Qiyun <qiyun_yuan@c-sky.com>
This patch adds files related to VDSO and our VDSO only support
rt_sigreturn.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
