1 /* 2 * Author: Kumar Gala <galak@kernel.crashing.org> 3 * 4 * Copyright 2009 Freescale Semiconductor Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published by the 8 * Free Software Foundation; either version 2 of the License, or (at your 9 * option) any later version. 10 */ 11 12 #include <linux/stddef.h> 13 #include <linux/kernel.h> 14 #include <linux/smp.h> 15 #include <linux/threads.h> 16 #include <linux/hardirq.h> 17 18 #include <asm/dbell.h> 19 #include <asm/irq_regs.h> 20 21 #ifdef CONFIG_SMP 22 void doorbell_setup_this_cpu(void) 23 { 24 unsigned long tag = mfspr(SPRN_PIR) & 0x3fff; 25 26 smp_muxed_ipi_set_data(smp_processor_id(), tag); 27 } 28 29 void doorbell_cause_ipi(int cpu, unsigned long data) 30 { 31 /* Order previous accesses vs. msgsnd, which is treated as a store */ 32 mb(); 33 ppc_msgsnd(PPC_DBELL, 0, data); 34 } 35 36 void doorbell_exception(struct pt_regs *regs) 37 { 38 struct pt_regs *old_regs = set_irq_regs(regs); 39 40 irq_enter(); 41 42 may_hard_irq_enable(); 43 44 smp_ipi_demux(); 45 46 irq_exit(); 47 set_irq_regs(old_regs); 48 } 49 #else /* CONFIG_SMP */ 50 void doorbell_exception(struct pt_regs *regs) 51 { 52 printk(KERN_WARNING "Received doorbell on non-smp system\n"); 53 } 54 #endif /* CONFIG_SMP */ 55 56