diff mbox series

[3/3] riscv: Support HAVE_SOFTIRQ_ON_OWN_STACK

Message ID 20220903163808.1954131-4-guoren@kernel.org (mailing list archive)
State New, archived
Headers show
Series riscv: Add GENERIC_ENTRY & IRQ_STACKS support | expand

Commit Message

Guo Ren Sept. 3, 2022, 4:38 p.m. UTC 
From: Guo Ren <guoren@linux.alibaba.com>

Add the HAVE_SOFTIRQ_ON_OWN_STACK feature for the IRQ_STACKS config. The
irq and softirq use the same independent irq_stack of percpu by time
division multiplexing.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
 arch/riscv/Kconfig      |  7 ++++---
 arch/riscv/kernel/irq.c | 15 +++++++++++++++
 2 files changed, 19 insertions(+), 3 deletions(-)

Comments

kernel test robot Sept. 3, 2022, 5:58 p.m. UTC | #1 
Hi,

I love your patch! Perhaps something to improve:

[auto build test WARNING on soc/for-next]
[also build test WARNING on linus/master v6.0-rc3 next-20220901]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/guoren-kernel-org/riscv-Add-GENERIC_ENTRY-IRQ_STACKS-support/20220904-003954
base:   https://git.kernel.org/pub/scm/linux/kernel/git/soc/soc.git for-next
config: riscv-allyesconfig (https://download.01.org/0day-ci/archive/20220904/202209040118.GmG1Lby1-lkp@intel.com/config)
compiler: riscv64-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/6ed1ef93b372116f7d4586b13bfd352e19453740
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review guoren-kernel-org/riscv-Add-GENERIC_ENTRY-IRQ_STACKS-support/20220904-003954
        git checkout 6ed1ef93b372116f7d4586b13bfd352e19453740
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash arch/riscv/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> arch/riscv/kernel/irq.c:48:6: warning: no previous prototype for 'do_softirq_own_stack' [-Wmissing-prototypes]
      48 | void do_softirq_own_stack(void)
         |      ^~~~~~~~~~~~~~~~~~~~
   arch/riscv/kernel/irq.c:74:25: warning: no previous prototype for 'handle_riscv_irq' [-Wmissing-prototypes]
      74 | asmlinkage void noinstr handle_riscv_irq(struct pt_regs *regs)
         |                         ^~~~~~~~~~~~~~~~
   arch/riscv/kernel/irq.c:85:25: warning: no previous prototype for 'do_riscv_irq' [-Wmissing-prototypes]
      85 | asmlinkage void noinstr do_riscv_irq(struct pt_regs *regs)
         |                         ^~~~~~~~~~~~


vim +/do_softirq_own_stack +48 arch/riscv/kernel/irq.c

    47	
  > 48	void do_softirq_own_stack(void)
    49	{
    50		ulong *sp = per_cpu(irq_stack_ptr, smp_processor_id());
    51	
    52		call_on_stack(NULL, sp, do_riscv_softirq, 0);
    53	}
    54	#endif /* CONFIG_PREEMPT_RT */
    55
Guo Ren Sept. 4, 2022, 12:04 a.m. UTC | #2 
Oops, there is no warning with 6.0-rc3. But it's a bug, I fixed that by:

diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index afc8c030c222..5871eccbbd94 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -12,6 +12,7 @@
 #include <linux/syscalls.h>
 #include <linux/resume_user_mode.h>
 #include <linux/linkage.h>
+#include <linux/entry-common.h>

 #include <asm/ucontext.h>
 #include <asm/vdso.h>
@@ -272,7 +273,7 @@ static void handle_signal(struct ksignal *ksig,
struct pt_regs *regs)
        signal_setup_done(ret, ksig, 0);
 }

-void arch_do_signal_or_restart(struct pt_regs *regs, bool has_signal)
+void arch_do_signal_or_restart(struct pt_regs *regs)
 {
        struct ksignal ksig;

On Sun, Sep 4, 2022 at 1:59 AM kernel test robot <lkp@intel.com> wrote:
>
> Hi,
>
> I love your patch! Perhaps something to improve:
>
> [auto build test WARNING on soc/for-next]
> [also build test WARNING on linus/master v6.0-rc3 next-20220901]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/guoren-kernel-org/riscv-Add-GENERIC_ENTRY-IRQ_STACKS-support/20220904-003954
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/soc/soc.git for-next
> config: riscv-allyesconfig (https://download.01.org/0day-ci/archive/20220904/202209040118.GmG1Lby1-lkp@intel.com/config)
> compiler: riscv64-linux-gcc (GCC) 12.1.0
> reproduce (this is a W=1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # https://github.com/intel-lab-lkp/linux/commit/6ed1ef93b372116f7d4586b13bfd352e19453740
>         git remote add linux-review https://github.com/intel-lab-lkp/linux
>         git fetch --no-tags linux-review guoren-kernel-org/riscv-Add-GENERIC_ENTRY-IRQ_STACKS-support/20220904-003954
>         git checkout 6ed1ef93b372116f7d4586b13bfd352e19453740
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash arch/riscv/
>
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@intel.com>
>
> All warnings (new ones prefixed by >>):
>
> >> arch/riscv/kernel/irq.c:48:6: warning: no previous prototype for 'do_softirq_own_stack' [-Wmissing-prototypes]
>       48 | void do_softirq_own_stack(void)
>          |      ^~~~~~~~~~~~~~~~~~~~
>    arch/riscv/kernel/irq.c:74:25: warning: no previous prototype for 'handle_riscv_irq' [-Wmissing-prototypes]
>       74 | asmlinkage void noinstr handle_riscv_irq(struct pt_regs *regs)
>          |                         ^~~~~~~~~~~~~~~~
>    arch/riscv/kernel/irq.c:85:25: warning: no previous prototype for 'do_riscv_irq' [-Wmissing-prototypes]
>       85 | asmlinkage void noinstr do_riscv_irq(struct pt_regs *regs)
>          |                         ^~~~~~~~~~~~
>
>
> vim +/do_softirq_own_stack +48 arch/riscv/kernel/irq.c
>
>     47
>   > 48  void do_softirq_own_stack(void)
>     49  {
>     50          ulong *sp = per_cpu(irq_stack_ptr, smp_processor_id());
>     51
>     52          call_on_stack(NULL, sp, do_riscv_softirq, 0);
>     53  }
>     54  #endif /* CONFIG_PREEMPT_RT */
>     55
>
> --
> 0-DAY CI Kernel Test Service
> https://01.org/lkp
diff mbox series

Patch

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index a8a12b4ba1a9..da548ed7d107 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -434,12 +434,13 @@  config FPU
 	  If you don't know what to do here, say Y.
 
 config IRQ_STACKS
-	bool "Independent irq stacks"
+	bool "Independent irq & softirq stacks"
 	default y
 	select HAVE_IRQ_EXIT_ON_IRQ_STACK
+	select HAVE_SOFTIRQ_ON_OWN_STACK
 	help
-	  Add independent irq stacks for percpu to prevent kernel stack overflows.
-	  We may save some memory footprint by disabling IRQ_STACKS.
+	  Add independent irq & softirq stacks for percpu to prevent kernel stack
+	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
 
 endmenu # "Platform type"
 
diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
index eec5c38100b6..282acfee7304 100644
--- a/arch/riscv/kernel/irq.c
+++ b/arch/riscv/kernel/irq.c
@@ -38,6 +38,21 @@  static void init_irq_stacks(void)
 		per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
 }
 #endif /* CONFIG_VMAP_STACK */
+
+#ifndef CONFIG_PREEMPT_RT
+static void do_riscv_softirq(struct pt_regs *regs)
+{
+	__do_softirq();
+}
+
+void do_softirq_own_stack(void)
+{
+	ulong *sp = per_cpu(irq_stack_ptr, smp_processor_id());
+
+	call_on_stack(NULL, sp, do_riscv_softirq, 0);
+}
+#endif /* CONFIG_PREEMPT_RT */
+
 #else
 static void init_irq_stacks(void) {}
 #endif /* CONFIG_IRQ_STACKS */