From dd69d07a5a6c5a9ada85321ab0695e7978fc6f3e Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Tue, 13 Jun 2023 21:30:17 -0400 Subject: [PATCH] riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK Add the HAVE_SOFTIRQ_ON_OWN_STACK feature for the IRQ_STACKS config, and the irq and softirq use the same irq_stack of percpu. Tested-by: Jisheng Zhang Signed-off-by: Guo Ren Signed-off-by: Guo Ren Link: https://lore.kernel.org/r/20230614013018.2168426-3-guoren@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 6 ++++-- arch/riscv/kernel/irq.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+), 2 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index a8368fe..f515cb10 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -591,11 +591,13 @@ 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 help - Add independent irq stacks for percpu to prevent kernel stack overflows. + 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 a1dcf8e..d0577cc 100644 --- a/arch/riscv/kernel/irq.c +++ b/arch/riscv/kernel/irq.c @@ -11,6 +11,9 @@ #include #include #include +#include +#include +#include static struct fwnode_handle *(*__get_intc_node)(void); @@ -56,6 +59,38 @@ 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"); + } else +#endif + __do_softirq(); +} +#endif /* CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK */ + #else static void init_irq_stacks(void) {} #endif /* CONFIG_IRQ_STACKS */ -- 2.7.4