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/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2019 Western Digital Corporation or its affiliates.
*
* Authors:
* Anup Patel <anup.patel@wdc.com>
*/
#include <sbi/riscv_asm.h>
#include <sbi/riscv_barrier.h>
#include <sbi/riscv_encoding.h>
#include <sbi/sbi_console.h>
#include <sbi/sbi_error.h>
#include <sbi/sbi_hart.h>
#include <sbi/sbi_platform.h>
#include <sbi/sbi_pmu.h>
#include <sbi/sbi_scratch.h>
#include <sbi/sbi_timer.h>
static unsigned long time_delta_off;
static u64 (*get_time_val)(void);
static const struct sbi_timer_device *timer_dev = NULL;
#if __riscv_xlen == 32
static u64 get_ticks(void)
{
u32 lo, hi, tmp;
__asm__ __volatile__("1:\n"
"rdtimeh %0\n"
"rdtime %1\n"
"rdtimeh %2\n"
"bne %0, %2, 1b"
: "=&r"(hi), "=&r"(lo), "=&r"(tmp));
return ((u64)hi << 32) | lo;
}
#else
static u64 get_ticks(void)
{
unsigned long n;
__asm__ __volatile__("rdtime %0" : "=r"(n));
return n;
}
#endif
static void nop_delay_fn(void *opaque)
{
cpu_relax();
}
void sbi_timer_delay_loop(ulong units, u64 unit_freq,
void (*delay_fn)(void *), void *opaque)
{
u64 start_val, delta;
/* Do nothing if we don't have timer device */
if (!timer_dev || !get_time_val) {
sbi_printf("%s: called without timer device\n", __func__);
return;
}
/* Save starting timer value */
start_val = get_time_val();
/* Compute desired timer value delta */
delta = ((u64)timer_dev->timer_freq * (u64)units);
delta = delta / unit_freq;
/* Use NOP delay function if delay function not available */
if (!delay_fn)
delay_fn = nop_delay_fn;
/* Busy loop until desired timer value delta reached */
while ((get_time_val() - start_val) < delta)
delay_fn(opaque);
}
bool sbi_timer_waitms_until(bool (*predicate)(void *), void *arg,
uint64_t timeout_ms)
{
uint64_t start_time = sbi_timer_value();
uint64_t ticks =
(sbi_timer_get_device()->timer_freq / 1000) *
timeout_ms;
while(!predicate(arg))
if (sbi_timer_value() - start_time >= ticks)
return false;
return true;
}
u64 sbi_timer_value(void)
{
if (get_time_val)
return get_time_val();
return 0;
}
u64 sbi_timer_virt_value(void)
{
u64 *time_delta = sbi_scratch_offset_ptr(sbi_scratch_thishart_ptr(),
time_delta_off);
return sbi_timer_value() + *time_delta;
}
u64 sbi_timer_get_delta(void)
{
u64 *time_delta = sbi_scratch_offset_ptr(sbi_scratch_thishart_ptr(),
time_delta_off);
return *time_delta;
}
void sbi_timer_set_delta(ulong delta)
{
ulong *time_delta = sbi_scratch_offset_ptr(sbi_scratch_thishart_ptr(),
time_delta_off);
*time_delta = delta;
}
#if __riscv_xlen == 32
void sbi_timer_set_delta_upper(ulong delta_upper)
{
ulong *time_delta = sbi_scratch_offset_ptr(sbi_scratch_thishart_ptr(),
time_delta_off);
*(time_delta + 1) = delta_upper;
}
#endif
void sbi_timer_event_start(u64 next_event)
{
sbi_pmu_ctr_incr_fw(SBI_PMU_FW_SET_TIMER);
/**
* Update the stimecmp directly if available. This allows
* the older software to leverage sstc extension on newer hardware.
*/
if (sbi_hart_has_extension(sbi_scratch_thishart_ptr(), SBI_HART_EXT_SSTC)) {
csr_write64(CSR_STIMECMP, next_event);
} else if (timer_dev && timer_dev->timer_event_start) {
timer_dev->timer_event_start(next_event);
csr_clear(CSR_MIP, MIP_STIP);
}
csr_set(CSR_MIE, MIP_MTIP);
}
void sbi_timer_process(void)
{
csr_clear(CSR_MIE, MIP_MTIP);
/*
* If sstc extension is available, supervisor can receive the timer
* directly without M-mode come in between. This function should
* only invoked if M-mode programs the timer for its own purpose.
*/
if (!sbi_hart_has_extension(sbi_scratch_thishart_ptr(), SBI_HART_EXT_SSTC))
csr_set(CSR_MIP, MIP_STIP);
}
const struct sbi_timer_device *sbi_timer_get_device(void)
{
return timer_dev;
}
void sbi_timer_set_device(const struct sbi_timer_device *dev)
{
if (!dev || timer_dev)
return;
timer_dev = dev;
if (!get_time_val && timer_dev->timer_value)
get_time_val = timer_dev->timer_value;
}
int sbi_timer_init(struct sbi_scratch *scratch, bool cold_boot)
{
u64 *time_delta;
const struct sbi_platform *plat = sbi_platform_ptr(scratch);
int ret;
if (cold_boot) {
time_delta_off = sbi_scratch_alloc_offset(sizeof(*time_delta));
if (!time_delta_off)
return SBI_ENOMEM;
if (sbi_hart_has_csr(scratch, SBI_HART_CSR_TIME))
get_time_val = get_ticks;
ret = sbi_platform_timer_init(plat);
if (ret)
return ret;
} else {
if (!time_delta_off)
return SBI_ENOMEM;
}
time_delta = sbi_scratch_offset_ptr(scratch, time_delta_off);
*time_delta = 0;
if (timer_dev && timer_dev->warm_init) {
ret = timer_dev->warm_init();
if (ret)
return ret;
}
return 0;
}
void sbi_timer_exit(struct sbi_scratch *scratch)
{
if (timer_dev && timer_dev->timer_event_stop)
timer_dev->timer_event_stop();
csr_clear(CSR_MIP, MIP_STIP);
csr_clear(CSR_MIE, MIP_MTIP);
}
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