From: Guo Ren <guoren@kernel.org>
To: "Björn Töpel" <bjorn@kernel.org>
Cc: arnd@arndb.de, palmer@rivosinc.com, tglx@linutronix.de,
peterz@infradead.org, luto@kernel.org,
conor.dooley@microchip.com, heiko@sntech.de, jszhang@kernel.org,
lazyparser@gmail.com, falcon@tinylab.org, chenhuacai@kernel.org,
apatel@ventanamicro.com, atishp@atishpatra.org,
palmer@dabbelt.com, paul.walmsley@sifive.com,
mark.rutland@arm.com, zouyipeng@huawei.com,
bigeasy@linutronix.de, David.Laight@aculab.com,
chenzhongjin@huawei.com, greentime.hu@sifive.com,
andy.chiu@sifive.com, linux-arch@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
Guo Ren <guoren@linux.alibaba.com>
Subject: Re: [PATCH -next V8 06/14] riscv: convert to generic entry
Date: Tue, 6 Dec 2022 14:39:58 +0800 [thread overview]
Message-ID: <CAJF2gTRsZMM9vPqRWEwzOOhW2czo8uOJEtTGjixJig1kdQP1hg@mail.gmail.com> (raw)
In-Reply-To: <874jua9lcp.fsf@all.your.base.are.belong.to.us>
On Mon, Dec 5, 2022 at 6:49 PM Björn Töpel <bjorn@kernel.org> wrote:
>
> guoren@kernel.org writes:
>
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > This patch converts riscv to use the generic entry infrastructure from
> > kernel/entry/*. The generic entry makes maintainers' work easier and
> > codes more elegant. Here are the changes than before:
> >
> > - More clear entry.S with handle_exception and ret_from_exception
> > - Get rid of complex custom signal implementation
> > - More readable syscall procedure
> > - Little modification on ret_from_fork & ret_from_kernel_thread
> > - Wrap with irqentry_enter/exit and syscall_enter/exit_from_user_mode
> > - Use the standard preemption code instead of custom
> >
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Signed-off-by: Guo Ren <guoren@kernel.org>
> > Suggested-by: Huacai Chen <chenhuacai@kernel.org>
> > Tested-by: Yipeng Zou <zouyipeng@huawei.com>
> > ---
>
> [...]
>
> > diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c
> > index 5d3f2fbeb33c..c86d0eafdf6a 100644
> > --- a/arch/riscv/kernel/sys_riscv.c
> > +++ b/arch/riscv/kernel/sys_riscv.c
> > @@ -5,8 +5,10 @@
> > * Copyright (C) 2017 SiFive
> > */
> >
> > +#include <linux/entry-common.h>
> > #include <linux/syscalls.h>
> > #include <asm/unistd.h>
> > +#include <asm/syscall.h>
> > #include <asm/cacheflush.h>
> > #include <asm-generic/mman-common.h>
> >
> > @@ -69,3 +71,28 @@ SYSCALL_DEFINE3(riscv_flush_icache, uintptr_t, start, uintptr_t, end,
> >
> > return 0;
> > }
> > +
> > +typedef long (*syscall_t)(ulong, ulong, ulong, ulong, ulong, ulong, ulong);
> > +
> > +asmlinkage void do_sys_ecall_u(struct pt_regs *regs)
> > +{
> > + syscall_t syscall;
> > + ulong nr = regs->a7;
> > +
> > + regs->epc += 4;
> > + regs->orig_a0 = regs->a0;
> > + regs->a0 = -ENOSYS;
> > +
> > + nr = syscall_enter_from_user_mode(regs, nr);
> > +#ifdef CONFIG_COMPAT
> > + if ((regs->status & SR_UXL) == SR_UXL_32)
> > + syscall = compat_sys_call_table[nr];
> > + else
> > +#endif
> > + syscall = sys_call_table[nr];
> > +
> > + if (nr < NR_syscalls)
> > + regs->a0 = syscall(regs->orig_a0, regs->a1, regs->a2,
> > + regs->a3, regs->a4, regs->a5,
> > regs->a6);
>
> Now that we're doing the "pt_regs to call" dance, it would make sense to
> introduce a syscall wrapper (like x86 and arm64) for riscv, so that we
> don't need to unwrap all regs for all syscalls (See __MAP() in
> include/linux/syscalls.h). That would be an optimization, so it could be
> done as a follow-up, and not part of the series.
Thx for the reminder; I will have a look at "pt_regs to call."
>
>
> Björn
--
Best Regards
Guo Ren
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2022-12-06 6:40 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-03 7:50 [PATCH -next V8 00/14] riscv: Add GENERIC_ENTRY support and related features guoren
2022-11-03 7:50 ` [PATCH -next V8 01/14] compiler_types.h: Add __noinstr_section() for noinstr guoren
2022-12-05 9:12 ` Björn Töpel
2022-11-03 7:50 ` [PATCH -next V8 02/14] riscv: elf_kexec: Fixup compile warning guoren
2022-12-05 9:13 ` Björn Töpel
2022-12-06 4:39 ` Guo Ren
2022-11-03 7:50 ` [PATCH -next V8 03/14] riscv: compat_syscall_table: " guoren
2022-12-05 9:13 ` Björn Töpel
2022-11-03 7:50 ` [PATCH -next V8 04/14] riscv: ptrace: Remove duplicate operation guoren
2022-12-05 9:34 ` Björn Töpel
2022-12-06 4:41 ` Guo Ren
2022-11-03 7:50 ` [PATCH -next V8 05/14] riscv: traps: Add noinstr to prevent instrumentation inserted guoren
2022-11-03 7:50 ` [PATCH -next V8 06/14] riscv: convert to generic entry guoren
2022-11-27 16:25 ` Ben Hutchings
2022-11-28 2:42 ` Guo Ren
2022-12-05 10:49 ` Björn Töpel
2022-12-06 6:39 ` Guo Ren [this message]
2022-11-03 7:50 ` [PATCH -next V8 07/14] riscv: Support HAVE_IRQ_EXIT_ON_IRQ_STACK guoren
2022-11-03 7:50 ` [PATCH -next V8 08/14] riscv: Support HAVE_SOFTIRQ_ON_OWN_STACK guoren
2022-11-03 7:50 ` [PATCH -next V8 09/14] riscv: Add config of thread stack size guoren
2022-11-03 7:50 ` [PATCH -next V8 10/14] riscv: Typo fixup for addi -> andi in comment guoren
2022-12-05 9:18 ` Björn Töpel
2022-11-03 7:50 ` [PATCH -next V8 11/14] riscv: Add support for STACKLEAK gcc plugin guoren
2022-11-03 7:50 ` [PATCH -next V8 12/14] riscv: remove extra level wrappers of trace_hardirqs_{on,off} guoren
2022-11-03 7:50 ` [PATCH -next V8 13/14] riscv: consolidate ret_from_kernel_thread into ret_from_fork guoren
2022-11-03 7:50 ` [PATCH -next V8 14/14] riscv: entry: consolidate general regs saving/restoring guoren
2022-11-23 15:26 ` [PATCH -next V8 00/14] riscv: Add GENERIC_ENTRY support and related features Jisheng Zhang
2022-12-05 9:46 ` Björn Töpel
2022-12-06 6:12 ` Guo Ren
2022-12-06 7:03 ` Björn Töpel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAJF2gTRsZMM9vPqRWEwzOOhW2czo8uOJEtTGjixJig1kdQP1hg@mail.gmail.com \
--to=guoren@kernel.org \
--cc=David.Laight@aculab.com \
--cc=andy.chiu@sifive.com \
--cc=apatel@ventanamicro.com \
--cc=arnd@arndb.de \
--cc=atishp@atishpatra.org \
--cc=bigeasy@linutronix.de \
--cc=bjorn@kernel.org \
--cc=chenhuacai@kernel.org \
--cc=chenzhongjin@huawei.com \
--cc=conor.dooley@microchip.com \
--cc=falcon@tinylab.org \
--cc=greentime.hu@sifive.com \
--cc=guoren@linux.alibaba.com \
--cc=heiko@sntech.de \
--cc=jszhang@kernel.org \
--cc=lazyparser@gmail.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=luto@kernel.org \
--cc=mark.rutland@arm.com \
--cc=palmer@dabbelt.com \
--cc=palmer@rivosinc.com \
--cc=paul.walmsley@sifive.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=zouyipeng@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).