On 11/11/2019 16.33, Janosch Frank wrote: > We need to load cr0 to have access to all fprs during save and restore > of fprs. Saving conditionally on basis of the CR0 AFP bit would be a > pain. > > Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx> > --- > s390x/cstart64.S | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/s390x/cstart64.S b/s390x/cstart64.S > index 8e2b21e..043e34a 100644 > --- a/s390x/cstart64.S > +++ b/s390x/cstart64.S > @@ -94,7 +94,7 @@ memsetxc: > stmg %r0, %r15, GEN_LC_SW_INT_GRS > /* save cr0 */ > stctg %c0, %c0, GEN_LC_SW_INT_CR0 > - /* load initial cr0 again */ > + /* load a cr0 that has the AFP control bit which enables all FPRs */ > larl %r1, initial_cr0 > lctlg %c0, %c0, 0(%r1) > /* save fprs 0-15 + fpc */ > @@ -139,7 +139,7 @@ diag308_load_reset: > xgr %r2, %r2 > br %r14 > /* Success path */ > - /* We lost cr0 due to the reset */ > + /* load a cr0 that has the AFP control bit which enables all FPRs */ > 0: larl %r1, initial_cr0 > lctlg %c0, %c0, 0(%r1) > RESTORE_REGS > Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx>
