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linux/arch/mips/include/asm/r4k-timer.h

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[MIPS] Add support for MIPS CMP platform. Signed-off-by: Chris Dearman <chris@mips.com> Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-04-29 00:14:26 +08:00
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2008 by Ralf Baechle (ralf@linux-mips.org)
*/
#ifndef __ASM_R4K_TYPES_H
#define __ASM_R4K_TYPES_H
#include <linux/compiler.h>
#ifdef CONFIG_SYNC_R4K
MIPS: Synchronize MIPS count one CPU at a time The current implementation of synchronise_count_{master,slave} blocks slave CPUs in early boot until all of them come up. This no longer works because blocking a CPU with interrupts off after notifying the CPU to be online causes problems with the current kernel. Specifically, after the workqueue changes (commit a08489c569dc1 "Pull workqueue changes from Tejun Heo") the CPU_ONLINE notification callback workqueue_cpu_up_callback() will hang on wait_for_completion(&idle_rebind.done), if the slave CPUs are blocked for synchronize_count_slave(). The changes are to update synchronize_count_{master,slave}() to handle one CPU at a time and to call synchronise_count_master() in __cpu_up() so that the CPU_ONLINE notification goes out only after the COP0 COUNT register is synchronized. [ralf@linux-mips.org: This matter only to those few platforms which are using the cp0 counter as their clocksource which are XLP, XLR and MIPS' CMP solution.] Signed-off-by: Jayachandran C <jchandra@broadcom.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/4216/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-08-14 21:26:13 +08:00
extern void synchronise_count_master(int cpu);
extern void synchronise_count_slave(int cpu);
[MIPS] Add support for MIPS CMP platform. Signed-off-by: Chris Dearman <chris@mips.com> Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-04-29 00:14:26 +08:00
#else
MIPS: Synchronize MIPS count one CPU at a time The current implementation of synchronise_count_{master,slave} blocks slave CPUs in early boot until all of them come up. This no longer works because blocking a CPU with interrupts off after notifying the CPU to be online causes problems with the current kernel. Specifically, after the workqueue changes (commit a08489c569dc1 "Pull workqueue changes from Tejun Heo") the CPU_ONLINE notification callback workqueue_cpu_up_callback() will hang on wait_for_completion(&idle_rebind.done), if the slave CPUs are blocked for synchronize_count_slave(). The changes are to update synchronize_count_{master,slave}() to handle one CPU at a time and to call synchronise_count_master() in __cpu_up() so that the CPU_ONLINE notification goes out only after the COP0 COUNT register is synchronized. [ralf@linux-mips.org: This matter only to those few platforms which are using the cp0 counter as their clocksource which are XLP, XLR and MIPS' CMP solution.] Signed-off-by: Jayachandran C <jchandra@broadcom.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/4216/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-08-14 21:26:13 +08:00
static inline void synchronise_count_master(int cpu)
[MIPS] Add support for MIPS CMP platform. Signed-off-by: Chris Dearman <chris@mips.com> Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-04-29 00:14:26 +08:00
{
}
MIPS: Synchronize MIPS count one CPU at a time The current implementation of synchronise_count_{master,slave} blocks slave CPUs in early boot until all of them come up. This no longer works because blocking a CPU with interrupts off after notifying the CPU to be online causes problems with the current kernel. Specifically, after the workqueue changes (commit a08489c569dc1 "Pull workqueue changes from Tejun Heo") the CPU_ONLINE notification callback workqueue_cpu_up_callback() will hang on wait_for_completion(&idle_rebind.done), if the slave CPUs are blocked for synchronize_count_slave(). The changes are to update synchronize_count_{master,slave}() to handle one CPU at a time and to call synchronise_count_master() in __cpu_up() so that the CPU_ONLINE notification goes out only after the COP0 COUNT register is synchronized. [ralf@linux-mips.org: This matter only to those few platforms which are using the cp0 counter as their clocksource which are XLP, XLR and MIPS' CMP solution.] Signed-off-by: Jayachandran C <jchandra@broadcom.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/4216/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-08-14 21:26:13 +08:00
static inline void synchronise_count_slave(int cpu)
[MIPS] Add support for MIPS CMP platform. Signed-off-by: Chris Dearman <chris@mips.com> Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-04-29 00:14:26 +08:00
{
}
#endif
#endif /* __ASM_R4K_TYPES_H */