From 55dd23eca666876e6028aa35d5e391cfced54871 Mon Sep 17 00:00:00 2001 From: Daniel Hellstrom Date: Mon, 2 May 2011 00:08:54 +0000 Subject: sparc32, sun4d: Implemented SMP IPIs support for SUN4D machines The sun4d does not seem to have a distingstion between soft and hard IRQs. When generating IPIs the generated IRQ looks like a hard IRQ, this patch adds a "IPI check" in the sun4d irq trap handler at a predefined IRQ number (SUN4D_IPI_IRQ). Before generating an IPI a per-cpu memory structure is modified for the "IPI check" to successfully detect a IPI request to a specific processor, the check clears the IPI work requested. All three IPIs (resched, single and cpu-mask) use the same IRQ number. The IPI IRQ should preferrably be on a separate IRQ and definitly not shared with IRQ handlers requesting IRQ with IRQF_SHARED. Signed-off-by: Daniel Hellstrom Signed-off-by: David S. Miller --- arch/sparc/kernel/sun4d_irq.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'arch/sparc/kernel/sun4d_irq.c') diff --git a/arch/sparc/kernel/sun4d_irq.c b/arch/sparc/kernel/sun4d_irq.c index b830914e32d3..a9ea60eb2c10 100644 --- a/arch/sparc/kernel/sun4d_irq.c +++ b/arch/sparc/kernel/sun4d_irq.c @@ -156,6 +156,15 @@ void sun4d_handler_irq(int pil, struct pt_regs *regs) cc_set_iclr(1 << pil); +#ifdef CONFIG_SMP + /* + * Check IPI data structures after IRQ has been cleared. Hard and Soft + * IRQ can happen at the same time, so both cases are always handled. + */ + if (pil == SUN4D_IPI_IRQ) + sun4d_ipi_interrupt(); +#endif + old_regs = set_irq_regs(regs); irq_enter(); if (sbusl == 0) { -- cgit v1.2.3