arc/kernel/smp.c

1 // SPDX-License-Identifier: GPL-2.0-only
3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
6  *   -- Added support for Inter Processor Interrupts
9  *    -- Initial Write (Borrowed heavily from ARM)
54 		return -EINVAL;  in arc_get_cpu_map()
57 		return -EINVAL;  in arc_get_cpu_map()
64  * "possible-cpus" property in DeviceTree pretend all [0..NR_CPUS-1] exist.
70 	if (arc_get_cpu_map("possible-cpus", &cpumask)) {  in arc_init_cpu_possible()
71 		pr_warn("Failed to get possible-cpus from dtb, pretending all %u cpus exist\n",  in arc_init_cpu_possible()
86  * - Initialise the CPU possible map early - this describes the CPUs
88  * - Call early smp init hook. This can initialize a specific multi-core
117  * Default smp boot helper for Run-on-reset case where all cores start off
118  * together. Non-masters need to wait for Master to start running.
119  * This is implemented using a flag in memory, which Non-masters spin-wait on.
120  * Master sets it to cpu-id of core to "ungate" it.
145 	/* for halt-on-reset, we've waited already */  in arc_platform_smp_wait_to_boot()
175 	current->active_mm = mm;  in start_kernel_secondary()
178 	/* Some SMP H/w setup - for each cpu */  in start_kernel_secondary()
182 	if (machine_desc->init_per_cpu)  in start_kernel_secondary()
183 		machine_desc->init_per_cpu(cpu);  in start_kernel_secondary()
195  * Called from kernel_init( ) -> smp_init( ) - for each CPU
198  *  -It booted, but was halted in head.S
199  *  -It was configured to halt-on-reset
228 		return -1;  in __cpu_up()
248  * In arches with IRQ for each msg type (above), receiver can use IRQ-id  to
249  * figure out what msg was sent. For those which don't (ARC has dedicated IPI
250  * IRQ), the msg-type needs to be conveyed via per-cpu data
275 	 * Call the platform specific IPI kick function, but avoid if possible:  in ipi_send_msg_one()
278 	 * IPI corresponding to that msg. This is true, even if it is already in  in ipi_send_msg_one()
279 	 * IPI handler, because !@old means it has not yet dequeued the msg(s)  in ipi_send_msg_one()
280 	 * so @new msg can be a free-loader  in ipi_send_msg_one()
320  * ipi_cpu_stop - handle IPI from smp_send_stop()
352  * arch-common ISR to handle for inter-processor interrupts
353  * Has hooks for platform specific IPI
360 	pr_debug("IPI [%ld] received on cpu %d\n",  in do_IPI()
367 	 * "dequeue" the msg corresponding to this IPI (and possibly other  in do_IPI()
378 			pr_info("IPI with bogus msg %ld in %ld\n", msg, copy);  in do_IPI()
386  * API called by platform code to hookup arch-common ISR to their IPI IRQ
388  * Note: If IPI is provided by platform (vs. say ARC MCIP), their intc setup/map
389  * function needs to call irq_set_percpu_devid() for IPI IRQ, otherwise
406 		rc = request_percpu_irq(virq, do_IPI, "IPI Interrupt", dev);  in smp_ipi_irq_setup()