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. Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx> Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx> Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20231106163738.1116942-3-nrb@xxxxxxxxxxxxx Signed-off-by: Nico Boehr <nrb@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 f629b6d..5beaf15 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 35c1145..d01f8a8 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 3f993a3..e990c18 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. + * @use_dat: specifies whether to use DAT or not + * @as: specifies the address space mode to use. Not set if use_dat is false. + * + * 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. + */ +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 b474d70..9a179d6 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); } /* -- 2.41.0
