diff options
Diffstat (limited to 'arch/s390/kernel/vdso32/clock_gettime.S')
| -rw-r--r-- | arch/s390/kernel/vdso32/clock_gettime.S | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/arch/s390/kernel/vdso32/clock_gettime.S b/arch/s390/kernel/vdso32/clock_gettime.S new file mode 100644 index 000000000..ada5c11a1 --- /dev/null +++ b/arch/s390/kernel/vdso32/clock_gettime.S @@ -0,0 +1,179 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Userland implementation of clock_gettime() for 32 bits processes in a + * s390 kernel for use in the vDSO + * + * Copyright IBM Corp. 2008 + * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) + */ +#include <asm/vdso.h> +#include <asm/asm-offsets.h> +#include <asm/unistd.h> +#include <asm/dwarf.h> +#include <asm/ptrace.h> + + .text + .align 4 + .globl __kernel_clock_gettime + .type __kernel_clock_gettime,@function +__kernel_clock_gettime: + CFI_STARTPROC + ahi %r15,-16 + CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16 + CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD + basr %r5,0 +0: al %r5,21f-0b(%r5) /* get &_vdso_data */ + chi %r2,__CLOCK_REALTIME_COARSE + je 10f + chi %r2,__CLOCK_REALTIME + je 11f + chi %r2,__CLOCK_MONOTONIC_COARSE + je 9f + chi %r2,__CLOCK_MONOTONIC + jne 19f + + /* CLOCK_MONOTONIC */ +1: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */ + tml %r4,0x0001 /* pending update ? loop */ + jnz 1b + stcke 0(%r15) /* Store TOD clock */ + lm %r0,%r1,1(%r15) + s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ + sl %r1,__VDSO_XTIME_STAMP+4(%r5) + brc 3,2f + ahi %r0,-1 +2: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */ + lr %r2,%r0 + l %r0,__VDSO_TK_MULT(%r5) + ltr %r1,%r1 + mr %r0,%r0 + jnm 3f + a %r0,__VDSO_TK_MULT(%r5) +3: alr %r0,%r2 + al %r0,__VDSO_WTOM_NSEC(%r5) + al %r1,__VDSO_WTOM_NSEC+4(%r5) + brc 12,5f + ahi %r0,1 +5: l %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ + srdl %r0,0(%r2) /* >> tk->shift */ + l %r2,__VDSO_WTOM_SEC+4(%r5) + cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */ + jne 1b + basr %r5,0 +6: ltr %r0,%r0 + jnz 7f + cl %r1,20f-6b(%r5) + jl 8f +7: ahi %r2,1 + sl %r1,20f-6b(%r5) + brc 3,6b + ahi %r0,-1 + j 6b +8: st %r2,0(%r3) /* store tp->tv_sec */ + st %r1,4(%r3) /* store tp->tv_nsec */ + lhi %r2,0 + ahi %r15,16 + CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD + CFI_RESTORE 15 + br %r14 + + /* CLOCK_MONOTONIC_COARSE */ + CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16 + CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD +9: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */ + tml %r4,0x0001 /* pending update ? loop */ + jnz 9b + l %r2,__VDSO_WTOM_CRS_SEC+4(%r5) + l %r1,__VDSO_WTOM_CRS_NSEC+4(%r5) + cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */ + jne 9b + j 8b + + /* CLOCK_REALTIME_COARSE */ +10: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */ + tml %r4,0x0001 /* pending update ? loop */ + jnz 10b + l %r2,__VDSO_XTIME_CRS_SEC+4(%r5) + l %r1,__VDSO_XTIME_CRS_NSEC+4(%r5) + cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */ + jne 10b + j 17f + + /* CLOCK_REALTIME */ +11: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */ + tml %r4,0x0001 /* pending update ? loop */ + jnz 11b + stcke 0(%r15) /* Store TOD clock */ + lm %r0,%r1,__VDSO_TS_END(%r5) /* TOD steering end time */ + s %r0,1(%r15) /* no - ts_steering_end */ + sl %r1,5(%r15) + brc 3,22f + ahi %r0,-1 +22: ltr %r0,%r0 /* past end of steering? */ + jm 24f + srdl %r0,15 /* 1 per 2^16 */ + tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */ + jz 23f + lcr %r0,%r0 /* negative TOD offset */ + lcr %r1,%r1 + je 23f + ahi %r0,-1 +23: a %r0,1(%r15) /* add TOD timestamp */ + al %r1,5(%r15) + brc 12,25f + ahi %r0,1 + j 25f +24: lm %r0,%r1,1(%r15) /* load TOD timestamp */ +25: s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ + sl %r1,__VDSO_XTIME_STAMP+4(%r5) + brc 3,12f + ahi %r0,-1 +12: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */ + lr %r2,%r0 + l %r0,__VDSO_TK_MULT(%r5) + ltr %r1,%r1 + mr %r0,%r0 + jnm 13f + a %r0,__VDSO_TK_MULT(%r5) +13: alr %r0,%r2 + al %r0,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */ + al %r1,__VDSO_XTIME_NSEC+4(%r5) + brc 12,14f + ahi %r0,1 +14: l %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ + srdl %r0,0(%r2) /* >> tk->shift */ + l %r2,__VDSO_XTIME_SEC+4(%r5) + cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */ + jne 11b + basr %r5,0 +15: ltr %r0,%r0 + jnz 16f + cl %r1,20f-15b(%r5) + jl 17f +16: ahi %r2,1 + sl %r1,20f-15b(%r5) + brc 3,15b + ahi %r0,-1 + j 15b +17: st %r2,0(%r3) /* store tp->tv_sec */ + st %r1,4(%r3) /* store tp->tv_nsec */ + lhi %r2,0 + ahi %r15,16 + CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD + CFI_RESTORE 15 + br %r14 + + /* Fallback to system call */ + CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16 + CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD +19: lhi %r1,__NR_clock_gettime + svc 0 + ahi %r15,16 + CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD + CFI_RESTORE 15 + br %r14 + CFI_ENDPROC + +20: .long 1000000000 +21: .long _vdso_data - 0b + .size __kernel_clock_gettime,.-__kernel_clock_gettime |