| Message ID | 20230516130456.256205-2-nrb@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390x: Add support for running guests without MSO/MSL | expand |
On Tue, 16 May 2023 15:04:51 +0200 Nico Boehr <nrb@linux.ibm.com> wrote: > 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 | 38 ++++++++++++++++++++++++++++++++++++++ > lib/s390x/mmu.c | 5 +++-- > 3 files changed, 45 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..1180ec44d72f 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 +105,43 @@ 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 *irq_psw = irq_psws[0]; irq_psw != NULL; irq_psw++) { just call it psw, or cur_psw, it's a little confusing otherwise add in arch_def.c: #define PSW_MASK_AS 0x0000C00000000000UL > + if (!dat) > + irq_psw->mask &= ~PSW_MASK_DAT; cur_psw->mask &= ~(PSW_MASK_DAT | PSW_MASK_AS); if (dat) cur_psw->mask |= PSW_MASK_DAT | BIT_ULL(63 - 16); alternatively, you can redefine psw with a bitfield (as you mentioned offline): cur_psw->mask.dat = dat; if (dat) cur_psw->mask.as = as; > + else > + irq_psw->mask |= PSW_MASK_DAT | as << (63 - 16); otherwise here you're ORing stuff to other stuff, if you had 3 and you OR 0 you get 3, but you actually want 0 > + } > + > + mb(); what's the purpose of this? > +} > + > 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 Claudio Imbrenda (2023-05-16 19:17:24) [...] > > diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c > > index 3f993a363ae2..1180ec44d72f 100644 > > --- a/lib/s390x/interrupt.c > > +++ b/lib/s390x/interrupt.c [...] > > +void irq_set_dat_mode(bool dat, uint64_t as) > > +{ [...] > > + for (struct psw *irq_psw = irq_psws[0]; irq_psw != NULL; irq_psw++) { > > just call it psw, or cur_psw, it's a little confusing otherwise will do. [...] > alternatively, you can redefine psw with a bitfield (as you mentioned > offline): > > cur_psw->mask.dat = dat; > if (dat) > cur_psw->mask.as = as; Yep, I'll go with that. > > > + else > > + irq_psw->mask |= PSW_MASK_DAT | as << (63 - 16); > > otherwise here you're ORing stuff to other stuff, if you had 3 and you > OR 0 you get 3, but you actually want 0 And that's the advantage of the bitfield. :) > > > + } > > + > > + mb(); > > what's the purpose of this? Make sure that the lowcore really has been written, but I think it's quite useless, since a function is a sequence point, right?
On Wed, 17 May 2023 14:25:01 +0200 Nico Boehr <nrb@linux.ibm.com> wrote: > Quoting Claudio Imbrenda (2023-05-16 19:17:24) > [...] > > > diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c > > > index 3f993a363ae2..1180ec44d72f 100644 > > > --- a/lib/s390x/interrupt.c > > > +++ b/lib/s390x/interrupt.c > [...] > > > +void irq_set_dat_mode(bool dat, uint64_t as) > > > +{ > [...] > > > + for (struct psw *irq_psw = irq_psws[0]; irq_psw != NULL; irq_psw++) { > > > > just call it psw, or cur_psw, it's a little confusing otherwise > > will do. > > [...] > > alternatively, you can redefine psw with a bitfield (as you mentioned > > offline): > > > > cur_psw->mask.dat = dat; > > if (dat) > > cur_psw->mask.as = as; > > Yep, I'll go with that. > > > > > > + else > > > + irq_psw->mask |= PSW_MASK_DAT | as << (63 - 16); > > > > otherwise here you're ORing stuff to other stuff, if you had 3 and you > > OR 0 you get 3, but you actually want 0 > > And that's the advantage of the bitfield. :) > > > > > > + } > > > + > > > + mb(); > > > > what's the purpose of this? > > Make sure that the lowcore really has been written, but I think it's quite > useless, since a function is a sequence point, right? yes
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..1180ec44d72f 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 +105,43 @@ 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 *irq_psw = irq_psws[0]; irq_psw != NULL; irq_psw++) { + if (!dat) + irq_psw->mask &= ~PSW_MASK_DAT; + else + irq_psw->mask |= PSW_MASK_DAT | as << (63 - 16); + } + + mb(); +} + 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 | 38 ++++++++++++++++++++++++++++++++++++++ lib/s390x/mmu.c | 5 +++-- 3 files changed, 45 insertions(+), 2 deletions(-)