| Message ID | 20230601070202.152094-3-nrb@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390x: Add support for running guests without MSO/MSL | expand |
On 6/1/23 09:01, Nico Boehr wrote: > When toggling DAT or switch address space modes, it is likely that s/switch/switching/ > interrupts should be handled in the same DAT or address space mode. > > Add a function which toggles DAT and address space mode for all > interruptions, except restart interrupts. > > Signed-off-by: Nico Boehr <nrb@linux.ibm.com> > --- > lib/s390x/asm/interrupt.h | 4 ++++ > lib/s390x/interrupt.c | 35 +++++++++++++++++++++++++++++++++++ > lib/s390x/mmu.c | 5 +++-- > 3 files changed, 42 insertions(+), 2 deletions(-) > > diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h > index 35c1145f0349..55759002dce2 100644 > --- a/lib/s390x/asm/interrupt.h > +++ b/lib/s390x/asm/interrupt.h > @@ -83,6 +83,10 @@ void expect_ext_int(void); > uint16_t clear_pgm_int(void); > void check_pgm_int_code(uint16_t code); > > +#define IRQ_DAT_ON true > +#define IRQ_DAT_OFF false > +void irq_set_dat_mode(bool dat, uint64_t as); > + > /* Activate low-address protection */ > static inline void low_prot_enable(void) > { > diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c > index 3f993a363ae2..d97b5a3a7e97 100644 > --- a/lib/s390x/interrupt.c > +++ b/lib/s390x/interrupt.c > @@ -9,6 +9,7 @@ > */ > #include <libcflat.h> > #include <asm/barrier.h> > +#include <asm/mem.h> > #include <asm/asm-offsets.h> > #include <sclp.h> > #include <interrupt.h> > @@ -104,6 +105,40 @@ void register_ext_cleanup_func(void (*f)(struct stack_frame_int *)) > THIS_CPU->ext_cleanup_func = f; > } > > +/** > + * irq_set_dat_mode - Set the DAT mode of all interrupt handlers, except for > + * restart. > + * This will update the DAT mode and address space mode of all interrupt new > + * PSWs. > + * > + * Since enabling DAT needs initalized CRs and the restart new PSW is often used s/initalized/initialized/ That seems to be a problematic word. > + * to initalize CRs, the restart new PSW is never touched to avoid the chicken > + * and egg situation. Same here. > + * > + * @dat specifies whether to use DAT or not > + * @as specifies the address space mode to use - one of AS_PRIM, AS_ACCR, > + * AS_SECN or AS_HOME. > + */ > +void irq_set_dat_mode(bool dat, uint64_t as) > +{ > + struct psw* irq_psws[] = { > + OPAQUE_PTR(GEN_LC_EXT_NEW_PSW), > + OPAQUE_PTR(GEN_LC_SVC_NEW_PSW), > + OPAQUE_PTR(GEN_LC_PGM_NEW_PSW), > + OPAQUE_PTR(GEN_LC_MCCK_NEW_PSW), > + OPAQUE_PTR(GEN_LC_IO_NEW_PSW), > + NULL /* sentinel */ > + }; > + > + assert(as == AS_PRIM || as == AS_ACCR || as == AS_SECN || as == AS_HOME); /* There are only 4 spaces */ assert(as < 4); ? > + > + for (struct psw *psw = irq_psws[0]; psw != NULL; psw++) { While this is ok in gnu99/c99 I generally prefer declaring the variable outside of the loop since it's more readable when using structs and unions. > + psw->dat = dat; > + if (dat) > + psw->as = as; Does that check even matter? > + } > +} > + > static void fixup_pgm_int(struct stack_frame_int *stack) > { > /* If we have an error on SIE we directly move to sie_exit */ > diff --git a/lib/s390x/mmu.c b/lib/s390x/mmu.c > index b474d7021d3f..199bd3fbc9c8 100644 > --- a/lib/s390x/mmu.c > +++ b/lib/s390x/mmu.c > @@ -12,6 +12,7 @@ > #include <asm/pgtable.h> > #include <asm/arch_def.h> > #include <asm/barrier.h> > +#include <asm/interrupt.h> > #include <vmalloc.h> > #include "mmu.h" > > @@ -41,8 +42,8 @@ static void mmu_enable(pgd_t *pgtable) > /* enable dat (primary == 0 set as default) */ > enable_dat(); > > - /* we can now also use DAT unconditionally in our PGM handler */ > - lowcore.pgm_new_psw.mask |= PSW_MASK_DAT; > + /* we can now also use DAT in all interrupt handlers */ > + irq_set_dat_mode(IRQ_DAT_ON, AS_PRIM); > } > > /*
Quoting Janosch Frank (2023-06-05 10:42:40) > On 6/1/23 09:01, Nico Boehr wrote: > > When toggling DAT or switch address space modes, it is likely that > > s/switch/switching/ Done [...] > > diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c > > index 3f993a363ae2..d97b5a3a7e97 100644 > > --- a/lib/s390x/interrupt.c > > +++ b/lib/s390x/interrupt.c > > @@ -9,6 +9,7 @@ > > */ > > #include <libcflat.h> > > #include <asm/barrier.h> > > +#include <asm/mem.h> > > #include <asm/asm-offsets.h> > > #include <sclp.h> > > #include <interrupt.h> > > @@ -104,6 +105,40 @@ void register_ext_cleanup_func(void (*f)(struct stack_frame_int *)) > > THIS_CPU->ext_cleanup_func = f; > > } > > > > +/** > > + * irq_set_dat_mode - Set the DAT mode of all interrupt handlers, except for > > + * restart. > > + * This will update the DAT mode and address space mode of all interrupt new > > + * PSWs. > > + * > > + * Since enabling DAT needs initalized CRs and the restart new PSW is often used > > s/initalized/initialized/ fixed > > +void irq_set_dat_mode(bool dat, uint64_t as) > > +{ > > + struct psw* irq_psws[] = { > > + OPAQUE_PTR(GEN_LC_EXT_NEW_PSW), > > + OPAQUE_PTR(GEN_LC_SVC_NEW_PSW), > > + OPAQUE_PTR(GEN_LC_PGM_NEW_PSW), > > + OPAQUE_PTR(GEN_LC_MCCK_NEW_PSW), > > + OPAQUE_PTR(GEN_LC_IO_NEW_PSW), > > + NULL /* sentinel */ > > + }; > > + > > + assert(as == AS_PRIM || as == AS_ACCR || as == AS_SECN || as == AS_HOME); > > /* There are only 4 spaces */ > assert(as < 4); ? Well you won't find that when when grepping for any of the AS_*, so no I don't think that's better. > > + > > + for (struct psw *psw = irq_psws[0]; psw != NULL; psw++) { > > While this is ok in gnu99/c99 I generally prefer declaring the variable > outside of the loop since it's more readable when using structs and unions. OK. > > > + psw->dat = dat; > > + if (dat) > > + psw->as = as; > > Does that check even matter? Well, when DAT is off, AS bacially becomes a don't care. I thought it's a good idea to preserve the AS in this case, but this can certainly be argued about. I updated the comment and clarified that AS is only touched if DAT is on. Let me know if you prefer removal of the if.
diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h index 35c1145f0349..55759002dce2 100644 --- a/lib/s390x/asm/interrupt.h +++ b/lib/s390x/asm/interrupt.h @@ -83,6 +83,10 @@ void expect_ext_int(void); uint16_t clear_pgm_int(void); void check_pgm_int_code(uint16_t code); +#define IRQ_DAT_ON true +#define IRQ_DAT_OFF false +void irq_set_dat_mode(bool dat, uint64_t as); + /* Activate low-address protection */ static inline void low_prot_enable(void) { diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c index 3f993a363ae2..d97b5a3a7e97 100644 --- a/lib/s390x/interrupt.c +++ b/lib/s390x/interrupt.c @@ -9,6 +9,7 @@ */ #include <libcflat.h> #include <asm/barrier.h> +#include <asm/mem.h> #include <asm/asm-offsets.h> #include <sclp.h> #include <interrupt.h> @@ -104,6 +105,40 @@ void register_ext_cleanup_func(void (*f)(struct stack_frame_int *)) THIS_CPU->ext_cleanup_func = f; } +/** + * irq_set_dat_mode - Set the DAT mode of all interrupt handlers, except for + * restart. + * This will update the DAT mode and address space mode of all interrupt new + * PSWs. + * + * Since enabling DAT needs initalized CRs and the restart new PSW is often used + * to initalize CRs, the restart new PSW is never touched to avoid the chicken + * and egg situation. + * + * @dat specifies whether to use DAT or not + * @as specifies the address space mode to use - one of AS_PRIM, AS_ACCR, + * AS_SECN or AS_HOME. + */ +void irq_set_dat_mode(bool dat, uint64_t as) +{ + struct psw* irq_psws[] = { + OPAQUE_PTR(GEN_LC_EXT_NEW_PSW), + OPAQUE_PTR(GEN_LC_SVC_NEW_PSW), + OPAQUE_PTR(GEN_LC_PGM_NEW_PSW), + OPAQUE_PTR(GEN_LC_MCCK_NEW_PSW), + OPAQUE_PTR(GEN_LC_IO_NEW_PSW), + NULL /* sentinel */ + }; + + assert(as == AS_PRIM || as == AS_ACCR || as == AS_SECN || as == AS_HOME); + + for (struct psw *psw = irq_psws[0]; psw != NULL; psw++) { + psw->dat = dat; + if (dat) + psw->as = as; + } +} + static void fixup_pgm_int(struct stack_frame_int *stack) { /* If we have an error on SIE we directly move to sie_exit */ diff --git a/lib/s390x/mmu.c b/lib/s390x/mmu.c index b474d7021d3f..199bd3fbc9c8 100644 --- a/lib/s390x/mmu.c +++ b/lib/s390x/mmu.c @@ -12,6 +12,7 @@ #include <asm/pgtable.h> #include <asm/arch_def.h> #include <asm/barrier.h> +#include <asm/interrupt.h> #include <vmalloc.h> #include "mmu.h" @@ -41,8 +42,8 @@ static void mmu_enable(pgd_t *pgtable) /* enable dat (primary == 0 set as default) */ enable_dat(); - /* we can now also use DAT unconditionally in our PGM handler */ - lowcore.pgm_new_psw.mask |= PSW_MASK_DAT; + /* we can now also use DAT in all interrupt handlers */ + irq_set_dat_mode(IRQ_DAT_ON, AS_PRIM); } /*
When toggling DAT or switch address space modes, it is likely that interrupts should be handled in the same DAT or address space mode. Add a function which toggles DAT and address space mode for all interruptions, except restart interrupts. Signed-off-by: Nico Boehr <nrb@linux.ibm.com> --- lib/s390x/asm/interrupt.h | 4 ++++ lib/s390x/interrupt.c | 35 +++++++++++++++++++++++++++++++++++ lib/s390x/mmu.c | 5 +++-- 3 files changed, 42 insertions(+), 2 deletions(-)