Re: [PATCH] powerpc/8xx: Reduce time spent in allow_user_access() and friends

2020-06-08 Thread Michael Ellerman
On Wed, 15 Apr 2020 10:06:09 + (UTC), Christophe Leroy wrote: > To enable/disable kernel access to user space, the 8xx has to > modify the properties of access group 1. This is done by writing > predefined values into SPRN_Mx_AP registers. > > As of today, a __put_user() gives: > > 0d64 :

[PATCH] powerpc/8xx: Reduce time spent in allow_user_access() and friends

2020-04-15 Thread Christophe Leroy
To enable/disable kernel access to user space, the 8xx has to modify the properties of access group 1. This is done by writing predefined values into SPRN_Mx_AP registers. As of today, a __put_user() gives: 0d64 : d64: 3d 20 4f ff lis r9,20479 d68: 61 29 ff ff ori r9,r9,