| Message ID | 20200715094045.381984-8-frankja@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | pc-bios: s390x: Cleanup part 2 | expand |
On 7/15/20 11:40 AM, Janosch Frank wrote: > Absolutely no need to set them up every time before we enable our > interrupt masks. > > Signed-off-by: Janosch Frank <frankja@linux.ibm.com> So, this one doesn't seem to be a great idea as a kernel loaded to 0x0 will overwrite the ext/io new PSWs and we'll then try to load a zero PSW when an IRQ hits. We have two options: * Add a piece of code that fixes the low core after a kernel has been loaded * Leave the code as is and add a comment, so other people don't fall into this trap. I'd be fine with both and for now I'd settle for the second option. > --- > pc-bios/s390-ccw/start.S | 30 +++++++++++++----------------- > 1 file changed, 13 insertions(+), 17 deletions(-) > > diff --git a/pc-bios/s390-ccw/start.S b/pc-bios/s390-ccw/start.S > index 01c4c21b26..0059a15d21 100644 > --- a/pc-bios/s390-ccw/start.S > +++ b/pc-bios/s390-ccw/start.S > @@ -34,6 +34,12 @@ loop: > remainder: > larl %r2,memsetxc > ex %r3,0(%r2) > + /* Store io new PSW */ > + larl %r1,io_new_psw > + mvc 0x1f0(16),0(%r1) > + /* Store ext new PSW */ > + larl %r1,external_new_psw > + mvc 0x1b0(16),0(%r1) > done: > j main /* And call C */ > > @@ -64,11 +70,6 @@ consume_sclp_int: > stctg %c0,%c0,0(%r15) > oi 6(%r15),0x2 > lctlg %c0,%c0,0(%r15) > - /* prepare external call handler */ > - larl %r1, external_new_code > - stg %r1, 0x1b8 > - larl %r1, external_new_mask > - mvc 0x1b0(8),0(%r1) > /* load enabled wait PSW */ > larl %r1, enabled_wait_psw > lpswe 0(%r1) > @@ -81,14 +82,9 @@ consume_sclp_int: > .globl consume_io_int > consume_io_int: > /* enable I/O interrupts in cr6 */ > - stctg %c6,%c6,0(%r15) > - oi 4(%r15), 0xff > - lctlg %c6,%c6,0(%r15) > - /* prepare i/o call handler */ > - larl %r1, io_new_code > - stg %r1, 0x1f8 > - larl %r1, io_new_mask > - mvc 0x1f0(8),0(%r1) > + stctg %c6, %c6, 0(%r15) > + oi 4(%r15), 0xff > + lctlg %c6, %c6, 0(%r15) > /* load enabled wait PSW */ > larl %r1, enabled_wait_psw > lpswe 0(%r1) > @@ -112,7 +108,7 @@ disabled_wait_psw: > .quad PSW_MASK_DWAIT, 0x0000000000000000 > enabled_wait_psw: > .quad PSW_MASK_EWAIT, 0x0000000000000000 > -external_new_mask: > - .quad PSW_MASK_64 > -io_new_mask: > - .quad PSW_MASK_64 > +external_new_psw: > + .quad PSW_MASK_64, external_new_code > +io_new_psw: > + .quad PSW_MASK_64, io_new_code >
On 15.07.20 15:13, Janosch Frank wrote: > On 7/15/20 11:40 AM, Janosch Frank wrote: >> Absolutely no need to set them up every time before we enable our >> interrupt masks. >> >> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> > > So, this one doesn't seem to be a great idea as a kernel loaded to 0x0 > will overwrite the ext/io new PSWs and we'll then try to load a zero PSW > when an IRQ hits. > > We have two options: > * Add a piece of code that fixes the low core after a kernel has been loaded > * Leave the code as is and add a comment, so other people don't fall > into this trap. > > I'd be fine with both and for now I'd settle for the second option. Yes, leave it as is and add a comment. > >> --- >> pc-bios/s390-ccw/start.S | 30 +++++++++++++----------------- >> 1 file changed, 13 insertions(+), 17 deletions(-) >> >> diff --git a/pc-bios/s390-ccw/start.S b/pc-bios/s390-ccw/start.S >> index 01c4c21b26..0059a15d21 100644 >> --- a/pc-bios/s390-ccw/start.S >> +++ b/pc-bios/s390-ccw/start.S >> @@ -34,6 +34,12 @@ loop: >> remainder: >> larl %r2,memsetxc >> ex %r3,0(%r2) >> + /* Store io new PSW */ >> + larl %r1,io_new_psw >> + mvc 0x1f0(16),0(%r1) >> + /* Store ext new PSW */ >> + larl %r1,external_new_psw >> + mvc 0x1b0(16),0(%r1) >> done: >> j main /* And call C */ >> >> @@ -64,11 +70,6 @@ consume_sclp_int: >> stctg %c0,%c0,0(%r15) >> oi 6(%r15),0x2 >> lctlg %c0,%c0,0(%r15) >> - /* prepare external call handler */ >> - larl %r1, external_new_code >> - stg %r1, 0x1b8 >> - larl %r1, external_new_mask >> - mvc 0x1b0(8),0(%r1) >> /* load enabled wait PSW */ >> larl %r1, enabled_wait_psw >> lpswe 0(%r1) >> @@ -81,14 +82,9 @@ consume_sclp_int: >> .globl consume_io_int >> consume_io_int: >> /* enable I/O interrupts in cr6 */ >> - stctg %c6,%c6,0(%r15) >> - oi 4(%r15), 0xff >> - lctlg %c6,%c6,0(%r15) >> - /* prepare i/o call handler */ >> - larl %r1, io_new_code >> - stg %r1, 0x1f8 >> - larl %r1, io_new_mask >> - mvc 0x1f0(8),0(%r1) >> + stctg %c6, %c6, 0(%r15) >> + oi 4(%r15), 0xff >> + lctlg %c6, %c6, 0(%r15) >> /* load enabled wait PSW */ >> larl %r1, enabled_wait_psw >> lpswe 0(%r1) >> @@ -112,7 +108,7 @@ disabled_wait_psw: >> .quad PSW_MASK_DWAIT, 0x0000000000000000 >> enabled_wait_psw: >> .quad PSW_MASK_EWAIT, 0x0000000000000000 >> -external_new_mask: >> - .quad PSW_MASK_64 >> -io_new_mask: >> - .quad PSW_MASK_64 >> +external_new_psw: >> + .quad PSW_MASK_64, external_new_code >> +io_new_psw: >> + .quad PSW_MASK_64, io_new_code >> > >
diff --git a/pc-bios/s390-ccw/start.S b/pc-bios/s390-ccw/start.S index 01c4c21b26..0059a15d21 100644 --- a/pc-bios/s390-ccw/start.S +++ b/pc-bios/s390-ccw/start.S @@ -34,6 +34,12 @@ loop: remainder: larl %r2,memsetxc ex %r3,0(%r2) + /* Store io new PSW */ + larl %r1,io_new_psw + mvc 0x1f0(16),0(%r1) + /* Store ext new PSW */ + larl %r1,external_new_psw + mvc 0x1b0(16),0(%r1) done: j main /* And call C */ @@ -64,11 +70,6 @@ consume_sclp_int: stctg %c0,%c0,0(%r15) oi 6(%r15),0x2 lctlg %c0,%c0,0(%r15) - /* prepare external call handler */ - larl %r1, external_new_code - stg %r1, 0x1b8 - larl %r1, external_new_mask - mvc 0x1b0(8),0(%r1) /* load enabled wait PSW */ larl %r1, enabled_wait_psw lpswe 0(%r1) @@ -81,14 +82,9 @@ consume_sclp_int: .globl consume_io_int consume_io_int: /* enable I/O interrupts in cr6 */ - stctg %c6,%c6,0(%r15) - oi 4(%r15), 0xff - lctlg %c6,%c6,0(%r15) - /* prepare i/o call handler */ - larl %r1, io_new_code - stg %r1, 0x1f8 - larl %r1, io_new_mask - mvc 0x1f0(8),0(%r1) + stctg %c6, %c6, 0(%r15) + oi 4(%r15), 0xff + lctlg %c6, %c6, 0(%r15) /* load enabled wait PSW */ larl %r1, enabled_wait_psw lpswe 0(%r1) @@ -112,7 +108,7 @@ disabled_wait_psw: .quad PSW_MASK_DWAIT, 0x0000000000000000 enabled_wait_psw: .quad PSW_MASK_EWAIT, 0x0000000000000000 -external_new_mask: - .quad PSW_MASK_64 -io_new_mask: - .quad PSW_MASK_64 +external_new_psw: + .quad PSW_MASK_64, external_new_code +io_new_psw: + .quad PSW_MASK_64, io_new_code
Absolutely no need to set them up every time before we enable our interrupt masks. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> --- pc-bios/s390-ccw/start.S | 30 +++++++++++++----------------- 1 file changed, 13 insertions(+), 17 deletions(-)