diff options
| author | Huacai Chen <chenhc@lemote.com> | 2014-03-21 18:44:09 +0800 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2014-03-31 18:17:12 +0200 |
| commit | c4a987db1b3cd89207cece4b8121c09cbfbc978a (patch) | |
| tree | d9dc9db58b7259ac9e986b948e8b9c0abbebff39 /arch/mips/include/asm/smp.h | |
| parent | 300459d558725cdada5ddebbe52c24ef6e1853d3 (diff) | |
MIPS: Loongson 3: Add CPU hotplug support
Tips of Loongson's CPU hotplug:
1, To fully shutdown a core in Loongson 3, the target core should go to
CKSEG1 and flush all L1 cache entries at first. Then, another core
(usually Core 0) can safely disable the clock of the target core. So
play_dead() call loongson3_play_dead() via CKSEG1 (both uncached and
unmmaped).
2, The default clocksource of Loongson is MIPS. Since clock source is a
global device, timekeeping need the CP0' Count registers of each core
be synchronous. Thus, when a core is up, we use a SMP_ASK_C0COUNT IPI
to ask Core-0's Count.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Hongliang Tao <taohl@lemote.com>
Signed-off-by: Hua Yan <yanh@lemote.com>
Tested-by: Alex Smith <alex.smith@imgtec.com>
Reviewed-by: Alex Smith <alex.smith@imgtec.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/6639
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/include/asm/smp.h')
| -rw-r--r-- | arch/mips/include/asm/smp.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h index eb6008758484..efa02acd3dd5 100644 --- a/arch/mips/include/asm/smp.h +++ b/arch/mips/include/asm/smp.h @@ -42,6 +42,7 @@ extern int __cpu_logical_map[NR_CPUS]; #define SMP_ICACHE_FLUSH 0x4 /* Used by kexec crashdump to save all cpu's state */ #define SMP_DUMP 0x8 +#define SMP_ASK_C0COUNT 0x10 extern volatile cpumask_t cpu_callin_map; |