On Thu, Dec 8, 2022 at 6:12 PM Björn Töpel <bjorn@xxxxxxxxxx> wrote: > > guoren@xxxxxxxxxx writes: > > > From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > > > > 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. > > > > Tested-by: Jisheng Zhang <jszhang@xxxxxxxxxx> > > Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > > Signed-off-by: Guo Ren <guoren@xxxxxxxxxx> > > --- > > arch/riscv/Kconfig | 7 ++++--- > > arch/riscv/kernel/irq.c | 33 +++++++++++++++++++++++++++++++++ > > 2 files changed, 37 insertions(+), 3 deletions(-) > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > index 0a9d4bdc0338..bd4c4ae4cdc9 100644 > > --- a/arch/riscv/Kconfig > > +++ b/arch/riscv/Kconfig > > @@ -447,12 +447,13 @@ config FPU > > If you don't know what to do here, say Y. > > > > config IRQ_STACKS > > - bool "Independent irq stacks" if EXPERT > > + bool "Independent irq & softirq stacks" if EXPERT > > default y > > select HAVE_IRQ_EXIT_ON_IRQ_STACK > > + select HAVE_SOFTIRQ_ON_OWN_STACK > > HAVE_IRQ_EXIT_ON_IRQ_STACK is used by softirq.c Shouldn't that be > selected introduced in this patch, instead of the previous one? This patch depends on the previous one. And the previous one could work separately. > > > 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. > > Same comment from previous patch. Please use the same wording/config as > other archs. > > > endmenu # "Platform type" > > > > diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c > > index 5d77f692b198..a6406da34937 100644 > > --- a/arch/riscv/kernel/irq.c > > +++ b/arch/riscv/kernel/irq.c > > @@ -11,6 +11,7 @@ > > #include <linux/seq_file.h> > > #include <asm/smp.h> > > #include <asm/vmap_stack.h> > > +#include <asm/softirq_stack.h> > > > > #ifdef CONFIG_IRQ_STACKS > > static DEFINE_PER_CPU(ulong *, irq_stack_ptr); > > @@ -38,6 +39,38 @@ static void init_irq_stacks(void) > > per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu); > > } > > #endif /* CONFIG_VMAP_STACK */ > > + > > +#ifdef CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK > > +void do_softirq_own_stack(void) > > +{ > > +#ifdef CONFIG_IRQ_STACKS > > + if (on_thread_stack()) { > > + ulong *sp = per_cpu(irq_stack_ptr, smp_processor_id()) > > + + IRQ_STACK_SIZE/sizeof(ulong); > > + __asm__ __volatile( > > + "addi sp, sp, -"RISCV_SZPTR "\n" > > + REG_S" ra, (sp) \n" > > + "addi sp, sp, -"RISCV_SZPTR "\n" > > + REG_S" s0, (sp) \n" > > + "addi s0, sp, 2*"RISCV_SZPTR "\n" > > + "move sp, %[sp] \n" > > + "call __do_softirq \n" > > + "addi sp, s0, -2*"RISCV_SZPTR"\n" > > + REG_L" s0, (sp) \n" > > + "addi sp, sp, "RISCV_SZPTR "\n" > > + REG_L" ra, (sp) \n" > > + "addi sp, sp, "RISCV_SZPTR "\n" > > + : > > + : [sp] "r" (sp) > > + : "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7", > > + "t0", "t1", "t2", "t3", "t4", "t5", "t6", > > + "memory"); > > Same as previous patch. Please avoid C&P and have a look at how > call_on_stack is done on x86. Okay. > > > Björn -- Best Regards Guo Ren