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 #include <asm/kvm_ppc.h> 21 22 #ifdef CONFIG_SMP 23 void doorbell_setup_this_cpu(void) 24 { 25 unsigned long tag = mfspr(SPRN_DOORBELL_CPUTAG) & PPC_DBELL_TAG_MASK; 26 27 smp_muxed_ipi_set_data(smp_processor_id(), tag); 28 } 29 30 void doorbell_cause_ipi(int cpu, unsigned long data) 31 { 32 /* Order previous accesses vs. msgsnd, which is treated as a store */ 33 mb(); 34 ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, data); 35 } 36 37 void doorbell_exception(struct pt_regs *regs) 38 { 39 struct pt_regs *old_regs = set_irq_regs(regs); 40 41 irq_enter(); 42 43 may_hard_irq_enable(); 44 45 kvmppc_set_host_ipi(smp_processor_id(), 0); 46 __this_cpu_inc(irq_stat.doorbell_irqs); 47 48 smp_ipi_demux(); 49 50 irq_exit(); 51 set_irq_regs(old_regs); 52 } 53 #else /* CONFIG_SMP */ 54 void doorbell_exception(struct pt_regs *regs) 55 { 56 printk(KERN_WARNING "Received doorbell on non-smp system\n"); 57 } 58 #endif /* CONFIG_SMP */ 59 60