According to the loongson spec
(http://www.loongson.cn/uploadfile/cpu/3B1500/Loongson_3B1500_cpu_user_1.pdf

)
and the macro definition(#define R_PERCORE_ISR(x) (0x40 + 0x8 * x)), we know
that the ISR size per CORE is 8, so here we need to divide
(addr - R_PERCORE_ISR(0)) by 8, not 4.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Alex Chen <alex.chen@huawei.com>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <5FA12391.8090400@huawei.com>
[PMD: Shortened subject]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>