| | 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 | |
| | 24 | /* |
| | 25 | * Doorbells must only be used if CPU_FTR_DBELL is available. |
| | 26 | * msgsnd is used in HV, and msgsndp is used in !HV. |
| | 27 | * |
| | 28 | * These should be used by platform code that is aware of restrictions. |
| | 29 | * Other arch code should use ->cause_ipi. |
| | 30 | * |
| | 31 | * doorbell_global_ipi() sends a dbell to any target CPU. |
| | 32 | * Must be used only by architectures that address msgsnd target |
| | 33 | * by PIR/get_hard_smp_processor_id. |
| | 34 | */ |
| | 35 | void doorbell_global_ipi(int cpu) |
| | 36 | { |
| | 37 | u32 tag = get_hard_smp_processor_id(cpu); |
| | 38 | |
| | 39 | kvmppc_set_host_ipi(cpu, 1); |
| | 40 | /* Order previous accesses vs. msgsnd, which is treated as a store */ |
| | 41 | ppc_msgsnd_sync(); |
| | 42 | ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag); |
| | 43 | } |
| | 44 | |
| | 45 | /* |
| | 46 | * doorbell_core_ipi() sends a dbell to a target CPU in the same core. |
| | 47 | * Must be used only by architectures that address msgsnd target |
| | 48 | * by TIR/cpu_thread_in_core. |
| | 49 | */ |
| | 50 | void doorbell_core_ipi(int cpu) |
| | 51 | { |
| | 52 | u32 tag = cpu_thread_in_core(cpu); |
| | 53 | |
| | 54 | kvmppc_set_host_ipi(cpu, 1); |
| | 55 | /* Order previous accesses vs. msgsnd, which is treated as a store */ |
| | 56 | ppc_msgsnd_sync(); |
| | 57 | ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag); |
| | 58 | } |
| | 59 | |
| | 60 | /* |
| | 61 | * Attempt to cause a core doorbell if destination is on the same core. |
| | 62 | * Returns 1 on success, 0 on failure. |
| | 63 | */ |
| | 64 | int doorbell_try_core_ipi(int cpu) |
| | 65 | { |
| | 66 | int this_cpu = get_cpu(); |
| | 67 | int ret = 0; |
| | 68 | |
| | 69 | if (cpumask_test_cpu(cpu, cpu_sibling_mask(this_cpu))) { |
| | 70 | doorbell_core_ipi(cpu); |
| | 71 | ret = 1; |
| | 72 | } |
| | 73 | |
| | 74 | put_cpu(); |
| | 75 | |
| | 76 | return ret; |
| | 77 | } |
| | 78 | |
| | 79 | void doorbell_exception(struct pt_regs *regs) |
| | 80 | { |
| | 81 | struct pt_regs *old_regs = set_irq_regs(regs); |
| | 82 | |
| | 83 | irq_enter(); |
| | 84 | |
| | 85 | ppc_msgsync(); |
| | 86 | |
| | 87 | may_hard_irq_enable(); |
| | 88 | |
| | 89 | kvmppc_set_host_ipi(smp_processor_id(), 0); |
| | 90 | __this_cpu_inc(irq_stat.doorbell_irqs); |
| | 91 | |
| | 92 | smp_ipi_demux_relaxed(); /* already performed the barrier */ |
| | 93 | |
| | 94 | irq_exit(); |
| | 95 | set_irq_regs(old_regs); |
| | 96 | } |
| | 97 | #else /* CONFIG_SMP */ |
| | 98 | void doorbell_exception(struct pt_regs *regs) |
| | 99 | { |
| | 100 | printk(KERN_WARNING "Received doorbell on non-smp system\n"); |
| | 101 | } |
| | 102 | #endif /* CONFIG_SMP */ |
| | 103 | |
projects / linux-2.6-block.git / blame_incremental