164 lines
4.4 KiB
ArmAsm
164 lines
4.4 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Userland implementation of clock_gettime() for 64 bits processes in a
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* s390 kernel for use in the vDSO
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*
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* Copyright IBM Corp. 2008
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
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*/
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#include <asm/vdso.h>
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#include <asm/asm-offsets.h>
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#include <asm/unistd.h>
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#include <asm/dwarf.h>
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#include <asm/ptrace.h>
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.text
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.align 4
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.globl __kernel_clock_gettime
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.type __kernel_clock_gettime,@function
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__kernel_clock_gettime:
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CFI_STARTPROC
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aghi %r15,-16
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CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16
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CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
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larl %r5,_vdso_data
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cghi %r2,__CLOCK_REALTIME_COARSE
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je 4f
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cghi %r2,__CLOCK_REALTIME
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je 5f
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cghi %r2,-3 /* Per-thread CPUCLOCK with PID=0, VIRT=1 */
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je 9f
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cghi %r2,__CLOCK_MONOTONIC_COARSE
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je 3f
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cghi %r2,__CLOCK_MONOTONIC
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jne 12f
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/* CLOCK_MONOTONIC */
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0: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
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tmll %r4,0x0001 /* pending update ? loop */
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jnz 0b
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stcke 0(%r15) /* Store TOD clock */
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lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
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lg %r0,__VDSO_WTOM_SEC(%r5)
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lg %r1,1(%r15)
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sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
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msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */
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alg %r1,__VDSO_WTOM_NSEC(%r5)
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srlg %r1,%r1,0(%r2) /* >> tk->shift */
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clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */
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jne 0b
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larl %r5,13f
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1: clg %r1,0(%r5)
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jl 2f
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slg %r1,0(%r5)
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aghi %r0,1
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j 1b
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2: stg %r0,0(%r3) /* store tp->tv_sec */
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stg %r1,8(%r3) /* store tp->tv_nsec */
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lghi %r2,0
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aghi %r15,16
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CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD
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CFI_RESTORE 15
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br %r14
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/* CLOCK_MONOTONIC_COARSE */
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CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16
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CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
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3: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
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tmll %r4,0x0001 /* pending update ? loop */
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jnz 3b
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lg %r0,__VDSO_WTOM_CRS_SEC(%r5)
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lg %r1,__VDSO_WTOM_CRS_NSEC(%r5)
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clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */
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jne 3b
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j 2b
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/* CLOCK_REALTIME_COARSE */
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4: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
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tmll %r4,0x0001 /* pending update ? loop */
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jnz 4b
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lg %r0,__VDSO_XTIME_CRS_SEC(%r5)
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lg %r1,__VDSO_XTIME_CRS_NSEC(%r5)
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clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */
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jne 4b
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j 7f
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/* CLOCK_REALTIME */
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5: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
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tmll %r4,0x0001 /* pending update ? loop */
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jnz 5b
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stcke 0(%r15) /* Store TOD clock */
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lg %r1,1(%r15)
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lg %r0,__VDSO_TS_END(%r5) /* TOD steering end time */
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slgr %r0,%r1 /* now - ts_steering_end */
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ltgr %r0,%r0 /* past end of steering ? */
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jm 17f
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srlg %r0,%r0,15 /* 1 per 2^16 */
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tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */
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jz 18f
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lcgr %r0,%r0 /* negative TOD offset */
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18: algr %r1,%r0 /* add steering offset */
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17: lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
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sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
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msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */
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alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */
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srlg %r1,%r1,0(%r2) /* >> tk->shift */
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lg %r0,__VDSO_XTIME_SEC(%r5) /* tk->xtime_sec */
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clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */
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jne 5b
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larl %r5,13f
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6: clg %r1,0(%r5)
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jl 7f
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slg %r1,0(%r5)
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aghi %r0,1
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j 6b
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7: stg %r0,0(%r3) /* store tp->tv_sec */
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stg %r1,8(%r3) /* store tp->tv_nsec */
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lghi %r2,0
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aghi %r15,16
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CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD
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CFI_RESTORE 15
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br %r14
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/* CPUCLOCK_VIRT for this thread */
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CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16
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CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
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9: lghi %r4,0
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icm %r0,15,__VDSO_ECTG_OK(%r5)
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jz 12f
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sacf 256 /* Magic ectg instruction */
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.insn ssf,0xc80100000000,__VDSO_ECTG_BASE(4),__VDSO_ECTG_USER(4),4
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sacf 0
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algr %r1,%r0 /* r1 = cputime as TOD value */
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mghi %r1,1000 /* convert to nanoseconds */
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srlg %r1,%r1,12 /* r1 = cputime in nanosec */
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lgr %r4,%r1
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larl %r5,13f
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srlg %r1,%r1,9 /* divide by 1000000000 */
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mlg %r0,8(%r5)
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srlg %r0,%r0,11 /* r0 = tv_sec */
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stg %r0,0(%r3)
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msg %r0,0(%r5) /* calculate tv_nsec */
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slgr %r4,%r0 /* r4 = tv_nsec */
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stg %r4,8(%r3)
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lghi %r2,0
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aghi %r15,16
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CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD
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CFI_RESTORE 15
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br %r14
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/* Fallback to system call */
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CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16
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CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
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12: lghi %r1,__NR_clock_gettime
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svc 0
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aghi %r15,16
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CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD
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CFI_RESTORE 15
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br %r14
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CFI_ENDPROC
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13: .quad 1000000000
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14: .quad 19342813113834067
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.size __kernel_clock_gettime,.-__kernel_clock_gettime
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