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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)
- {
- u64 *time_delta = sbi_scratch_offset_ptr(sbi_scratch_thishart_ptr(),
- time_delta_off);
- *time_delta = (u64)delta;
- }
- void sbi_timer_set_delta_upper(ulong delta_upper)
- {
- u64 *time_delta = sbi_scratch_offset_ptr(sbi_scratch_thishart_ptr(),
- time_delta_off);
- *time_delta &= 0xffffffffULL;
- *time_delta |= ((u64)delta_upper << 32);
- }
- 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)) {
- #if __riscv_xlen == 32
- csr_write(CSR_STIMECMP, next_event & 0xFFFFFFFF);
- csr_write(CSR_STIMECMPH, next_event >> 32);
- #else
- csr_write(CSR_STIMECMP, next_event);
- #endif
- } 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);
- if (cold_boot) {
- time_delta_off = sbi_scratch_alloc_offset(sizeof(*time_delta));
- if (!time_delta_off)
- return SBI_ENOMEM;
- if (sbi_hart_has_extension(scratch, SBI_HART_EXT_TIME))
- get_time_val = get_ticks;
- } else {
- if (!time_delta_off)
- return SBI_ENOMEM;
- }
- time_delta = sbi_scratch_offset_ptr(scratch, time_delta_off);
- *time_delta = 0;
- return sbi_platform_timer_init(plat, cold_boot);
- }
- 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);
- sbi_platform_timer_exit(sbi_platform_ptr(scratch));
- }
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