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![Andre Przywara](/assets/img/avatar_default.png)
For 64-bit ARM systems we provide just a timer_read_counter() implementation and rely on the generic non-uclass get_ticks() function in lib/time.c to call the former. However this function is actually not 64-bit safe, as it assumes a "long" to be 32-bit. Beside the fact that the resulting uint64_t isn't bigger than "long" on 64-bit architectures and thus combining two counters makes no sense, we get all kind of weird results when we try to OR in the high value shifted by _32_ bits. So let's avoid that function at all and provide a straight forward get_ticks() implementation for ARMv8, which also is in line with ARMv7. This fixes occasional immediate time-out expiration issues I see on the Pine64 board. The root cause of this needs to be investigated, but this fix looks like the right thing anyway. Signed-off-by: Andre Przywara <andre.przywara@arm.com>
65 lines
1.3 KiB
C
65 lines
1.3 KiB
C
/*
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* (C) Copyright 2013
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* David Feng <fenghua@phytium.com.cn>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <command.h>
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#include <asm/system.h>
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DECLARE_GLOBAL_DATA_PTR;
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/*
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* Generic timer implementation of get_tbclk()
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*/
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unsigned long get_tbclk(void)
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{
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unsigned long cntfrq;
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asm volatile("mrs %0, cntfrq_el0" : "=r" (cntfrq));
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return cntfrq;
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}
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/*
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* Generic timer implementation of timer_read_counter()
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*/
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unsigned long timer_read_counter(void)
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{
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unsigned long cntpct;
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#ifdef CONFIG_SYS_FSL_ERRATUM_A008585
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/* This erratum number needs to be confirmed to match ARM document */
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unsigned long temp;
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#endif
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isb();
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asm volatile("mrs %0, cntpct_el0" : "=r" (cntpct));
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#ifdef CONFIG_SYS_FSL_ERRATUM_A008585
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asm volatile("mrs %0, cntpct_el0" : "=r" (temp));
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while (temp != cntpct) {
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asm volatile("mrs %0, cntpct_el0" : "=r" (cntpct));
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asm volatile("mrs %0, cntpct_el0" : "=r" (temp));
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}
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#endif
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return cntpct;
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}
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unsigned long long get_ticks(void)
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{
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unsigned long ticks = timer_read_counter();
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gd->arch.tbl = ticks;
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return ticks;
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}
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unsigned long usec2ticks(unsigned long usec)
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{
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ulong ticks;
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if (usec < 1000)
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ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
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else
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ticks = ((usec / 10) * (get_tbclk() / 100000));
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return ticks;
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}
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