From: Huacai Chen Date: Fri, 21 Mar 2014 10:44:09 +0000 (+0800) Subject: MIPS: Loongson 3: Add CPU hotplug support X-Git-Tag: v3.15-rc1~125^2~14 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c4a987db1b3cd89207cece4b8121c09cbfbc978a;p=pandora-kernel.git 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 Signed-off-by: Hongliang Tao Signed-off-by: Hua Yan Tested-by: Alex Smith Reviewed-by: Alex Smith Cc: John Crispin Cc: Steven J. Hill Cc: Aurelien Jarno Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang Cc: Zhangjin Wu Patchwork: https://patchwork.linux-mips.org/patch/6639 Signed-off-by: Ralf Baechle --- Reading git-diff-tree failed