From: Paul Burton Date: Fri, 11 Jul 2014 15:44:34 +0000 (+0100) Subject: MIPS: ensure MSA gets disabled during boot X-Git-Tag: Ubuntu-snapdragon-4.4.0-1050.54~9865^2~15 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;ds=sidebyside;h=3587ea888b8ed0a3d7e792738b4db687d9e7f73b;p=mirror_ubuntu-artful-kernel.git MIPS: ensure MSA gets disabled during boot The kernel relies upon MSA being disabled when a task begins running, so that it can initialise or restore context in response to the resulting MSA disabled exception. Previously the state of MSA following boot was left as it was before the kernel ran, where MSA could potentially have been enabled. Explicitly disable it during boot to prevent any problems. As a nice side effect the code reads a little better too. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7306/ Signed-off-by: Ralf Baechle --- diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index cd252fd684b7..66b8fe97f739 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -144,14 +144,13 @@ static inline int __cpu_has_fpu(void) static inline unsigned long cpu_get_msa_id(void) { - unsigned long status, conf5, msa_id; + unsigned long status, msa_id; status = read_c0_status(); __enable_fpu(FPU_64BIT); - conf5 = read_c0_config5(); enable_msa(); msa_id = read_msa_ir(); - write_c0_config5(conf5); + disable_msa(); write_c0_status(status); return msa_id; }