| Message ID | 1582200043-21760-2-git-send-email-pmorel@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390x: Testing the Channel Subsystem I/O | expand |
On 2/20/20 1:00 PM, Pierre Morel wrote: > If we use multiple source of interrupts, for example, using SCLP > console to print information while using I/O interrupts, we need > to have a re-entrant register saving interruption handling. > > Instead of saving at a static memory address, let's save the base > registers and the floating point registers on the stack. > > Note that we keep the static register saving to recover from the > RESET tests. > > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > --- > s390x/cstart64.S | 23 +++++++++++++++++++++-- > 1 file changed, 21 insertions(+), 2 deletions(-) > > diff --git a/s390x/cstart64.S b/s390x/cstart64.S > index 9af6bb3..45da523 100644 > --- a/s390x/cstart64.S > +++ b/s390x/cstart64.S > @@ -118,6 +118,25 @@ memsetxc: > lmg %r0, %r15, GEN_LC_SW_INT_GRS > .endm > > +/* Save registers on the stack, so we can have stacked interrupts. */ > + .macro SAVE_IRQ_REGS > + slgfi %r15, 15 * 8 > + stmg %r0, %r14, 0(%r15) So this is just making some space on the stack and storing r0 - r14, right? Same is done for the floating point registers below. Could you add a comment above slgfi and stmg and explain what they do? A few words are enough. > + slgfi %r15, 16 * 8 > + .irp i, 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 > + std \i, \i * 8(%r15) > + .endr > + .endm > + > + .macro RESTORE_IRQ_REGS > + .irp i, 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 > + ld \i, \i * 8(%r15) > + .endr > + algfi %r15, 16 * 8 > + lmg %r0, %r14, 0(%r15) > + algfi %r15, 15 * 8 > + .endm > + > .section .text > /* > * load_reset calling convention: > @@ -182,9 +201,9 @@ mcck_int: > lpswe GEN_LC_MCCK_OLD_PSW > > io_int: > - SAVE_REGS > + SAVE_IRQ_REGS > brasl %r14, handle_io_int > - RESTORE_REGS > + RESTORE_IRQ_REGS > lpswe GEN_LC_IO_OLD_PSW > > svc_int: >
On 2020-04-22 09:47, Janosch Frank wrote: > On 2/20/20 1:00 PM, Pierre Morel wrote: >> If we use multiple source of interrupts, for example, using SCLP >> console to print information while using I/O interrupts, we need >> to have a re-entrant register saving interruption handling. >> >> Instead of saving at a static memory address, let's save the base >> registers and the floating point registers on the stack. >> >> Note that we keep the static register saving to recover from the >> RESET tests. >> >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> >> --- >> s390x/cstart64.S | 23 +++++++++++++++++++++-- >> 1 file changed, 21 insertions(+), 2 deletions(-) >> >> diff --git a/s390x/cstart64.S b/s390x/cstart64.S >> index 9af6bb3..45da523 100644 >> --- a/s390x/cstart64.S >> +++ b/s390x/cstart64.S >> @@ -118,6 +118,25 @@ memsetxc: >> lmg %r0, %r15, GEN_LC_SW_INT_GRS >> .endm >> >> +/* Save registers on the stack, so we can have stacked interrupts. */ >> + .macro SAVE_IRQ_REGS >> + slgfi %r15, 15 * 8 >> + stmg %r0, %r14, 0(%r15) > > So this is just making some space on the stack and storing r0 - r14, right? > > Same is done for the floating point registers below. > > Could you add a comment above slgfi and stmg and explain what they do? > A few words are enough. OK, thanks Regards, Pierre
diff --git a/s390x/cstart64.S b/s390x/cstart64.S index 9af6bb3..45da523 100644 --- a/s390x/cstart64.S +++ b/s390x/cstart64.S @@ -118,6 +118,25 @@ memsetxc: lmg %r0, %r15, GEN_LC_SW_INT_GRS .endm +/* Save registers on the stack, so we can have stacked interrupts. */ + .macro SAVE_IRQ_REGS + slgfi %r15, 15 * 8 + stmg %r0, %r14, 0(%r15) + slgfi %r15, 16 * 8 + .irp i, 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 + std \i, \i * 8(%r15) + .endr + .endm + + .macro RESTORE_IRQ_REGS + .irp i, 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 + ld \i, \i * 8(%r15) + .endr + algfi %r15, 16 * 8 + lmg %r0, %r14, 0(%r15) + algfi %r15, 15 * 8 + .endm + .section .text /* * load_reset calling convention: @@ -182,9 +201,9 @@ mcck_int: lpswe GEN_LC_MCCK_OLD_PSW io_int: - SAVE_REGS + SAVE_IRQ_REGS brasl %r14, handle_io_int - RESTORE_REGS + RESTORE_IRQ_REGS lpswe GEN_LC_IO_OLD_PSW svc_int:
If we use multiple source of interrupts, for example, using SCLP console to print information while using I/O interrupts, we need to have a re-entrant register saving interruption handling. Instead of saving at a static memory address, let's save the base registers and the floating point registers on the stack. Note that we keep the static register saving to recover from the RESET tests. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> --- s390x/cstart64.S | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-)