On Fri, 3 Nov 2023 10:29:31 +0100
Nico Boehr <nrb@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
> Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx>
> Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
> ---
> lib/s390x/asm/arch_def.h | 10 ++++++----
> lib/s390x/asm/interrupt.h | 2 ++
> lib/s390x/interrupt.c | 35 +++++++++++++++++++++++++++++++++++
> lib/s390x/mmu.c | 5 +++--
> 4 files changed, 46 insertions(+), 6 deletions(-)
>
> diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
> index f629b6d0a17f..5beaf15b57e7 100644
> --- a/lib/s390x/asm/arch_def.h
> +++ b/lib/s390x/asm/arch_def.h
> @@ -84,10 +84,12 @@ struct cpu {
> bool in_interrupt_handler;
> };
>
> -#define AS_PRIM 0
> -#define AS_ACCR 1
> -#define AS_SECN 2
> -#define AS_HOME 3
> +enum address_space {
> + AS_PRIM = 0,
> + AS_ACCR = 1,
> + AS_SECN = 2,
> + AS_HOME = 3
> +};
>
> #define PSW_MASK_DAT 0x0400000000000000UL
> #define PSW_MASK_IO 0x0200000000000000UL
> diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
> index 35c1145f0349..d01f8a89641a 100644
> --- a/lib/s390x/asm/interrupt.h
> +++ b/lib/s390x/asm/interrupt.h
> @@ -83,6 +83,8 @@ void expect_ext_int(void);
> uint16_t clear_pgm_int(void);
> void check_pgm_int_code(uint16_t code);
>
> +void irq_set_dat_mode(bool use_dat, enum address_space 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..e0a1713349f6 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.
(here)
> + * This will update the DAT mode and address space mode of all interrupt new
> + * PSWs.
> + *
> + * Since enabling DAT needs initialized CRs and the restart new PSW is often used
> + * to initialize CRs, the restart new PSW is never touched to avoid the chicken
> + * and egg situation.
> + *
> + * @use_dat specifies whether to use DAT or not
> + * @as specifies the address space mode to use. Not set if use_dat is false.
add the colon
* @use_dat:
* @as:
and move them up there ^
with that fixed:
Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
> + */
> +void irq_set_dat_mode(bool use_dat, enum address_space 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),
> + };
> + struct psw *psw;
> +
> + assert(as == AS_PRIM || as == AS_ACCR || as == AS_SECN || as == AS_HOME);
> +
> + for (size_t i = 0; i < ARRAY_SIZE(irq_psws); i++) {
> + psw = irq_psws[i];
> + psw->dat = use_dat;
> + if (use_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..9a179d6b8ec5 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(true, AS_PRIM);
> }
>
> /*
