diff options
| author | Will Deacon <will.deacon@arm.com> | 2012-11-29 22:19:01 (GMT) |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2012-12-05 11:20:03 (GMT) |
| commit | d91fb5c2677db90460611fce72e6a0af8f6c2a73 (patch) | |
| tree | 408562a6274dacea273c2df11f5513d2ad6b8938 /arch | |
| parent | f84a935db47d7f261c025ba9eaa7700261257469 (diff) | |
| download | linux-d91fb5c2677db90460611fce72e6a0af8f6c2a73.tar.xz | |
arm64: vdso: rework __do_get_tspec register allocation and return shift
In preparation for sub-ns precision in the vdso timespec maths, change
the __do_get_tspec register allocation so that we return the clocksource
shift value instead of the unused xtime tspec.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/kernel/vdso/gettimeofday.S | 88 |
1 files changed, 44 insertions, 44 deletions
diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S index 3a7bdcd..99b7d40 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -62,18 +62,18 @@ ENTRY(__kernel_gettimeofday) /* If tv is NULL, skip to the timezone code. */ cbz x0, 2f bl __do_get_tspec - seqcnt_check w13, 1b + seqcnt_check w9, 1b /* Convert ns to us. */ - mov x11, #1000 - udiv x10, x10, x11 - stp x9, x10, [x0, #TVAL_TV_SEC] + mov x13, #1000 + udiv x11, x11, x13 + stp x10, x11, [x0, #TVAL_TV_SEC] 2: /* If tz is NULL, return 0. */ cbz x1, 3f ldp w4, w5, [vdso_data, #VDSO_TZ_MINWEST] - seqcnt_read w13 - seqcnt_check w13, 1b + seqcnt_read w9 + seqcnt_check w9, 1b stp w4, w5, [x1, #TZ_MINWEST] 3: mov x0, xzr @@ -102,17 +102,17 @@ ENTRY(__kernel_clock_gettime) cbnz use_syscall, 7f bl __do_get_tspec - seqcnt_check w13, 1b + seqcnt_check w9, 1b cmp w0, #CLOCK_MONOTONIC b.ne 6f /* Get wtm timespec. */ - ldp x14, x15, [vdso_data, #VDSO_WTM_CLK_SEC] + ldp x13, x14, [vdso_data, #VDSO_WTM_CLK_SEC] /* Check the sequence counter. */ - seqcnt_read w13 - seqcnt_check w13, 1b + seqcnt_read w9 + seqcnt_check w9, 1b b 4f 2: cmp w0, #CLOCK_REALTIME_COARSE @@ -122,37 +122,37 @@ ENTRY(__kernel_clock_gettime) /* Get coarse timespec. */ adr vdso_data, _vdso_data 3: seqcnt_acquire - ldp x9, x10, [vdso_data, #VDSO_XTIME_CRS_SEC] + ldp x10, x11, [vdso_data, #VDSO_XTIME_CRS_SEC] /* Get wtm timespec. */ - ldp x14, x15, [vdso_data, #VDSO_WTM_CLK_SEC] + ldp x13, x14, [vdso_data, #VDSO_WTM_CLK_SEC] /* Check the sequence counter. */ - seqcnt_read w13 - seqcnt_check w13, 3b + seqcnt_read w9 + seqcnt_check w9, 3b cmp w0, #CLOCK_MONOTONIC_COARSE b.ne 6f 4: /* Add on wtm timespec. */ - add x9, x9, x14 - add x10, x10, x15 + add x10, x10, x13 + add x11, x11, x14 /* Normalise the new timespec. */ - mov x14, #NSEC_PER_SEC_LO16 - movk x14, #NSEC_PER_SEC_HI16, lsl #16 - cmp x10, x14 + mov x15, #NSEC_PER_SEC_LO16 + movk x15, #NSEC_PER_SEC_HI16, lsl #16 + cmp x11, x15 b.lt 5f - sub x10, x10, x14 - add x9, x9, #1 + sub x11, x11, x15 + add x10, x10, #1 5: - cmp x10, #0 + cmp x11, #0 b.ge 6f - add x10, x10, x14 - sub x9, x9, #1 + add x11, x11, x15 + sub x10, x10, #1 6: /* Store to the user timespec. */ - stp x9, x10, [x1, #TSPEC_TV_SEC] + stp x10, x11, [x1, #TSPEC_TV_SEC] mov x0, xzr ret x2 7: @@ -203,39 +203,39 @@ ENDPROC(__kernel_clock_getres) * Expects vdso_data to be initialised. * Clobbers the temporary registers (x9 - x15). * Returns: - * - (x9, x10) = (ts->tv_sec, ts->tv_nsec) - * - (x11, x12) = (xtime->tv_sec, xtime->tv_nsec) - * - w13 = vDSO sequence counter + * - w9 = vDSO sequence counter + * - (x10, x11) = (ts->tv_sec, ts->tv_nsec) + * - w12 = cs_shift */ ENTRY(__do_get_tspec) .cfi_startproc /* Read from the vDSO data page. */ ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST] - ldp x11, x12, [vdso_data, #VDSO_XTIME_CLK_SEC] - ldp w14, w15, [vdso_data, #VDSO_CS_MULT] - seqcnt_read w13 + ldp x13, x14, [vdso_data, #VDSO_XTIME_CLK_SEC] + ldp w11, w12, [vdso_data, #VDSO_CS_MULT] + seqcnt_read w9 /* Read the physical counter. */ isb - mrs x9, cntpct_el0 + mrs x15, cntpct_el0 /* Calculate cycle delta and convert to ns. */ - sub x10, x9, x10 + sub x10, x15, x10 /* We can only guarantee 56 bits of precision. */ - movn x9, #0xff00, lsl #48 - and x10, x9, x10 - mul x10, x10, x14 - lsr x10, x10, x15 + movn x15, #0xff00, lsl #48 + and x10, x15, x10 + mul x10, x10, x11 + lsr x10, x10, x12 /* Use the kernel time to calculate the new timespec. */ - add x10, x12, x10 - mov x14, #NSEC_PER_SEC_LO16 - movk x14, #NSEC_PER_SEC_HI16, lsl #16 - udiv x15, x10, x14 - add x9, x15, x11 - mul x14, x14, x15 - sub x10, x10, x14 + mov x11, #NSEC_PER_SEC_LO16 + movk x11, #NSEC_PER_SEC_HI16, lsl #16 + add x15, x10, x14 + udiv x14, x15, x11 + add x10, x13, x14 + mul x13, x14, x11 + sub x11, x15, x13 ret .cfi_endproc |