linux-stable.git/arch/mips/kernel/sync-r4k.c, branch linux-3.6.y Linux kernel stable tree MIPS: Synchronize MIPS count one CPU at a time 2012-08-17T08:57:28+00:00 Jayachandran C jchandra@broadcom.com 2012-08-14T13:26:13+00:00 cf9bfe55f24973a8f40e2c922a7e82cf09e486fd 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> 
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>
MIPS: sync-r4k: remove redundant irq operation 2012-07-19T09:23:44+00:00 Yong Zhang yong.zhang@windriver.com 2012-07-19T07:13:54+00:00 f2b88d65aa7adaa3996088e86ae497fe705e96f3 Since we have delayed irq enabling to ->smp_finish() Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Cc: Sergei Shtylyov <sshtylyov@mvista.com> Cc: David Daney <david.daney@cavium.com> Acked-by: David Daney <david.daney@cavium.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Since we have delayed irq enabling to ->smp_finish()

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Sergei Shtylyov <sshtylyov@mvista.com>
Cc: David Daney <david.daney@cavium.com>
Acked-by: David Daney <david.daney@cavium.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
atomic: use <linux/atomic.h> 2011-07-26T23:49:47+00:00 Arun Sharma asharma@fb.com 2011-07-26T23:09:06+00:00 60063497a95e716c9a689af3be2687d261f115b4 This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MIPS: CMP: Update sync-r4k for current kernel 2009-07-03T14:45:27+00:00 Tim Anderson tanderson@mvista.com 2009-06-17T23:40:34+00:00 eb9b5141a9815ef898ef6b6441f733e81c272600 This revises the sync-4k so it will boot and operate since the removal of expirelo from the timer code. Signed-off-by: Tim Anderson <tanderson@mvista.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
This revises the sync-4k so it will boot and operate since the removal of
expirelo from the timer code.

Signed-off-by: Tim Anderson <tanderson@mvista.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
[MIPS] Add support for MIPS CMP platform. 2008-04-28T16:14:26+00:00 Ralf Baechle ralf@linux-mips.org 2008-04-28T16:14:26+00:00 39b8d5254246ac56342b72f812255c8f7a74dca9 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> 
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>