From 48cf12d88969bd4238b8769767eb476970319d93 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Fri, 19 Mar 2021 06:34:43 +0000 Subject: powerpc/irq: Inline call_do_irq() and call_do_softirq() call_do_irq() and call_do_softirq() are simple enough to be worth inlining. Inlining them avoids an mflr/mtlr pair plus a save/reload on stack. This is inspired from S390 arch. Several other arches do more or less the same. The way sparc arch does seems odd thought. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210320122227.345427-1-mpe@ellerman.id.au --- arch/powerpc/kernel/irq.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) (limited to 'arch/powerpc/kernel/irq.c') diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 5b72abbff96c..260effc0a435 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -667,6 +667,47 @@ static inline void check_stack_overflow(void) } } +static __always_inline void call_do_softirq(const void *sp) +{ + /* Temporarily switch r1 to sp, call __do_softirq() then restore r1. */ + asm volatile ( + PPC_STLU " %%r1, %[offset](%[sp]) ;" + "mr %%r1, %[sp] ;" + "bl %[callee] ;" + PPC_LL " %%r1, 0(%%r1) ;" + : // Outputs + : // Inputs + [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_OVERHEAD), + [callee] "i" (__do_softirq) + : // Clobbers + "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6", + "cr7", "r0", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", + "r11", "r12" + ); +} + +static __always_inline void call_do_irq(struct pt_regs *regs, void *sp) +{ + register unsigned long r3 asm("r3") = (unsigned long)regs; + + /* Temporarily switch r1 to sp, call __do_irq() then restore r1. */ + asm volatile ( + PPC_STLU " %%r1, %[offset](%[sp]) ;" + "mr %%r1, %[sp] ;" + "bl %[callee] ;" + PPC_LL " %%r1, 0(%%r1) ;" + : // Outputs + "+r" (r3) + : // Inputs + [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_OVERHEAD), + [callee] "i" (__do_irq) + : // Clobbers + "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6", + "cr7", "r0", "r4", "r5", "r6", "r7", "r8", "r9", "r10", + "r11", "r12" + ); +} + void __do_irq(struct pt_regs *regs) { unsigned int irq; -- cgit v1.2.3