2 * SMP initialisation and IPI support
3 * Based on arch/arm64/kernel/smp.c
5 * Copyright (C) 2012 ARM Ltd.
6 * Copyright (C) 2015 Regents of the University of California
7 * Copyright (C) 2017 SiFive
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
22 #include <linux/interrupt.h>
23 #include <linux/smp.h>
24 #include <linux/sched.h>
27 #include <asm/tlbflush.h>
28 #include <asm/cacheflush.h>
30 /* A collection of single bit ipi messages. */
32 unsigned long bits ____cacheline_aligned;
33 } ipi_data[NR_CPUS] __cacheline_aligned;
35 enum ipi_message_type {
41 irqreturn_t handle_ipi(void)
43 unsigned long *pending_ipis = &ipi_data[smp_processor_id()].bits;
45 /* Clear pending IPI */
46 csr_clear(sip, SIE_SSIE);
51 /* Order bit clearing and data access. */
54 ops = xchg(pending_ipis, 0);
58 if (ops & (1 << IPI_RESCHEDULE))
61 if (ops & (1 << IPI_CALL_FUNC))
62 generic_smp_call_function_interrupt();
64 BUG_ON((ops >> IPI_MAX) != 0);
66 /* Order data access and bit testing. */
74 send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation)
79 for_each_cpu(i, to_whom)
80 set_bit(operation, &ipi_data[i].bits);
83 sbi_send_ipi(cpumask_bits(to_whom));
86 void arch_send_call_function_ipi_mask(struct cpumask *mask)
88 send_ipi_message(mask, IPI_CALL_FUNC);
91 void arch_send_call_function_single_ipi(int cpu)
93 send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC);
96 static void ipi_stop(void *unused)
102 void smp_send_stop(void)
104 on_each_cpu(ipi_stop, NULL, 1);
107 void smp_send_reschedule(int cpu)
109 send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);