Messages in this thread Patch in this message | | | From | Anup Patel <> | Subject | [PATCH v2 1/5] RISC-V: self-contained IPI handling routine | Date | Thu, 6 Sep 2018 18:06:47 +0530 |
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Currently, the IPI handling routine riscv_software_interrupt() does not take any argument and also does not perform irq_enter()/irq_exit().
This patch makes IPI handling routine more self-contained by: 1. Passing "pt_regs *" argument 2. Explicitly doing irq_enter()/irq_exit() 3. Explicitly save/restore "pt_regs *" using set_irq_regs()
With above changes, IPI handling routine does not depend on caller function to perform irq_enter()/irq_exit() and save/restore of "pt_regs *" hence its more self-contained. This also enables us to call IPI handling routine from IRQCHIP drivers.
Signed-off-by: Anup Patel <anup@brainfault.org> --- arch/riscv/include/asm/irq.h | 1 - arch/riscv/include/asm/smp.h | 3 +++ arch/riscv/kernel/irq.c | 16 ++++++++++------ arch/riscv/kernel/smp.c | 11 +++++++++-- 4 files changed, 22 insertions(+), 9 deletions(-)
diff --git a/arch/riscv/include/asm/irq.h b/arch/riscv/include/asm/irq.h index a873a72d0f00..8d5d1a9f7fae 100644 --- a/arch/riscv/include/asm/irq.h +++ b/arch/riscv/include/asm/irq.h @@ -18,7 +18,6 @@ #define NR_IRQS 0 void riscv_timer_interrupt(void); -void riscv_software_interrupt(void); void wait_for_software_interrupt(void); #include <asm-generic/irq.h> diff --git a/arch/riscv/include/asm/smp.h b/arch/riscv/include/asm/smp.h index 8145b8657d20..d7c3da05f200 100644 --- a/arch/riscv/include/asm/smp.h +++ b/arch/riscv/include/asm/smp.h @@ -51,6 +51,9 @@ void send_ipi_message(const struct cpumask *to_whom, /* SMP initialization hook for setup_arch */ void __init setup_smp(void); +/* Called from C code, this handles an IPI. */ +void handle_IPI(struct pt_regs *regs); + /* Hook for the generic smp_call_function_many() routine. */ void arch_send_call_function_ipi_mask(struct cpumask *mask); diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c index 7e14b0d9a71d..f5073dcbc560 100644 --- a/arch/riscv/kernel/irq.c +++ b/arch/riscv/kernel/irq.c @@ -26,12 +26,15 @@ asmlinkage void __irq_entry do_IRQ(struct pt_regs *regs, unsigned long cause) { - struct pt_regs *old_regs = set_irq_regs(regs); + struct pt_regs *old_regs; - irq_enter(); switch (cause & ~INTERRUPT_CAUSE_FLAG) { case INTERRUPT_CAUSE_TIMER: + old_regs = set_irq_regs(regs); + irq_enter(); riscv_timer_interrupt(); + irq_exit(); + set_irq_regs(old_regs); break; #ifdef CONFIG_SMP case INTERRUPT_CAUSE_SOFTWARE: @@ -39,18 +42,19 @@ asmlinkage void __irq_entry do_IRQ(struct pt_regs *regs, unsigned long cause) * We only use software interrupts to pass IPIs, so if a non-SMP * system gets one, then we don't know what to do. */ - riscv_software_interrupt(); + handle_IPI(regs); break; #endif case INTERRUPT_CAUSE_EXTERNAL: + old_regs = set_irq_regs(regs); + irq_enter(); handle_arch_irq(regs); + irq_exit(); + set_irq_regs(old_regs); break; default: panic("unexpected interrupt cause"); } - irq_exit(); - - set_irq_regs(old_regs); } /* diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c index 629456bb6122..9e7bcf705946 100644 --- a/arch/riscv/kernel/smp.c +++ b/arch/riscv/kernel/smp.c @@ -58,10 +58,13 @@ int setup_profiling_timer(unsigned int multiplier) return -EINVAL; } -void riscv_software_interrupt(void) +void handle_IPI(struct pt_regs *regs) { + struct pt_regs *old_regs = set_irq_regs(regs); unsigned long *pending_ipis = &ipi_data[smp_processor_id()].bits; + irq_enter(); + /* Clear pending IPI */ csr_clear(sip, SIE_SSIE); @@ -73,7 +76,7 @@ void riscv_software_interrupt(void) ops = xchg(pending_ipis, 0); if (ops == 0) - return; + goto done; if (ops & (1 << IPI_RESCHEDULE)) scheduler_ipi(); @@ -86,6 +89,10 @@ void riscv_software_interrupt(void) /* Order data access and bit testing. */ mb(); } + +done: + irq_exit(); + set_irq_regs(old_regs); } void -- 2.17.1
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