[PATCH 1/6] lib: utils/timer: Add ACLINT MTIMER library
Anup Patel
anup.patel at wdc.com
Sat Jun 12 09:03:16 PDT 2021
We add common ACLINT MTIMER library similar to the CLINT library
so that OpenSBI platforms can use it.
Signed-off-by: Anup Patel <anup.patel at wdc.com>
---
include/sbi_utils/timer/aclint_mtimer.h | 41 ++++++
lib/utils/timer/aclint_mtimer.c | 180 ++++++++++++++++++++++++
lib/utils/timer/objects.mk | 1 +
3 files changed, 222 insertions(+)
create mode 100644 include/sbi_utils/timer/aclint_mtimer.h
create mode 100644 lib/utils/timer/aclint_mtimer.c
diff --git a/include/sbi_utils/timer/aclint_mtimer.h b/include/sbi_utils/timer/aclint_mtimer.h
new file mode 100644
index 0000000..510bfa9
--- /dev/null
+++ b/include/sbi_utils/timer/aclint_mtimer.h
@@ -0,0 +1,41 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ * Anup Patel <anup.patel at wdc.com>
+ */
+
+#ifndef __TIMER_ACLINT_MTIMER_H__
+#define __TIMER_ACLINT_MTIMER_H__
+
+#include <sbi/sbi_types.h>
+
+#define ACLINT_MTIMER_ALIGN 0x1000
+#define ACLINT_MTIMER_SIZE 0x8000
+#define ACLINT_MTIMER_MAX_HARTS 4095
+
+#define CLINT_MTIMER_OFFSET 0x4000
+
+struct aclint_mtimer_data {
+ /* Public details */
+ unsigned long addr;
+ unsigned long size;
+ u32 first_hartid;
+ u32 hart_count;
+ bool has_64bit_mmio;
+ /* Private details (initialized and used by ACLINT MTIMER library) */
+ struct aclint_mtimer_data *time_delta_reference;
+ unsigned long time_delta_computed;
+ u64 time_delta;
+ u64 (*time_rd)(volatile u64 *addr);
+ void (*time_wr)(u64 value, volatile u64 *addr);
+};
+
+int aclint_mtimer_warm_init(void);
+
+int aclint_mtimer_cold_init(struct aclint_mtimer_data *mt,
+ struct aclint_mtimer_data *reference);
+
+#endif
diff --git a/lib/utils/timer/aclint_mtimer.c b/lib/utils/timer/aclint_mtimer.c
new file mode 100644
index 0000000..2c64ca8
--- /dev/null
+++ b/lib/utils/timer/aclint_mtimer.c
@@ -0,0 +1,180 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ * Anup Patel <anup.patel at wdc.com>
+ */
+
+#include <sbi/riscv_asm.h>
+#include <sbi/riscv_atomic.h>
+#include <sbi/riscv_io.h>
+#include <sbi/sbi_domain.h>
+#include <sbi/sbi_error.h>
+#include <sbi/sbi_hartmask.h>
+#include <sbi/sbi_ipi.h>
+#include <sbi/sbi_timer.h>
+#include <sbi_utils/timer/aclint_mtimer.h>
+
+#define MTIMER_CMP_OFF 0x0000
+#define MTIMER_VAL_OFF 0x7ff8
+
+static struct aclint_mtimer_data *mtimer_hartid2data[SBI_HARTMASK_MAX_BITS];
+
+#if __riscv_xlen != 32
+static u64 mtimer_time_rd64(volatile u64 *addr)
+{
+ return readq_relaxed(addr);
+}
+
+static void mtimer_time_wr64(u64 value, volatile u64 *addr)
+{
+ writeq_relaxed(value, addr);
+}
+#endif
+
+static u64 mtimer_time_rd32(volatile u64 *addr)
+{
+ u32 lo, hi;
+
+ do {
+ hi = readl_relaxed((u32 *)addr + 1);
+ lo = readl_relaxed((u32 *)addr);
+ } while (hi != readl_relaxed((u32 *)addr + 1));
+
+ return ((u64)hi << 32) | (u64)lo;
+}
+
+static void mtimer_time_wr32(u64 value, volatile u64 *addr)
+{
+ u32 mask = -1U;
+
+ writel_relaxed(value & mask, (void *)(addr));
+ writel_relaxed(value >> 32, (void *)(addr) + 0x04);
+}
+
+static u64 mtimer_value(void)
+{
+ struct aclint_mtimer_data *mt = mtimer_hartid2data[current_hartid()];
+ u64 *time_val = ((void *)mt->addr) + MTIMER_VAL_OFF;
+
+ /* Read MTIMER Time Value */
+ return mt->time_rd(time_val) + mt->time_delta;
+}
+
+static void mtimer_event_stop(void)
+{
+ u32 target_hart = current_hartid();
+ struct aclint_mtimer_data *mt = mtimer_hartid2data[target_hart];
+ u64 *time_cmp = (void *)mt->addr + MTIMER_CMP_OFF;
+
+ /* Clear MTIMER Time Compare */
+ mt->time_wr(-1ULL, &time_cmp[target_hart - mt->first_hartid]);
+}
+
+static void mtimer_event_start(u64 next_event)
+{
+ u32 target_hart = current_hartid();
+ struct aclint_mtimer_data *mt = mtimer_hartid2data[target_hart];
+ u64 *time_cmp = (void *)mt->addr + MTIMER_CMP_OFF;
+
+ /* Program MTIMER Time Compare */
+ mt->time_wr(next_event - mt->time_delta,
+ &time_cmp[target_hart - mt->first_hartid]);
+}
+
+static struct sbi_timer_device mtimer = {
+ .name = "aclint-mtimer",
+ .timer_value = mtimer_value,
+ .timer_event_start = mtimer_event_start,
+ .timer_event_stop = mtimer_event_stop
+};
+
+int aclint_mtimer_warm_init(void)
+{
+ u64 v1, v2, mv;
+ u32 target_hart = current_hartid();
+ struct aclint_mtimer_data *reference;
+ u64 *mt_time_val, *mt_time_cmp, *ref_time_val;
+ struct aclint_mtimer_data *mt = mtimer_hartid2data[target_hart];
+
+ if (!mt)
+ return SBI_ENODEV;
+
+ /*
+ * Compute delta if reference available
+ *
+ * We deliberately compute time_delta in warm init so that time_delta
+ * is computed on a HART which is going to use given MTIMER. We use
+ * atomic flag timer_delta_computed to ensure that only one HART does
+ * time_delta computation.
+ */
+ if (mt->time_delta_reference) {
+ reference = mt->time_delta_reference;
+ mt_time_val = (void *)mt->addr + MTIMER_VAL_OFF;
+ ref_time_val = (void *)reference->addr + MTIMER_VAL_OFF;
+ if (!atomic_raw_xchg_ulong(&mt->time_delta_computed, 1)) {
+ v1 = mt->time_rd(mt_time_val);
+ mv = reference->time_rd(ref_time_val);
+ v2 = mt->time_rd(mt_time_val);
+ mt->time_delta = mv - ((v1 / 2) + (v2 / 2));
+ }
+ }
+
+ /* Clear Time Compare */
+ mt_time_cmp = (void *)mt->addr + MTIMER_CMP_OFF;
+ mt->time_wr(-1ULL, &mt_time_cmp[target_hart - mt->first_hartid]);
+
+ return 0;
+}
+
+int aclint_mtimer_cold_init(struct aclint_mtimer_data *mt,
+ struct aclint_mtimer_data *reference)
+{
+ u32 i;
+ int rc;
+ unsigned long pos, region_size;
+ struct sbi_domain_memregion reg;
+
+ /* Sanity checks */
+ if (!mt || (mt->addr & (ACLINT_MTIMER_ALIGN - 1)) ||
+ (mt->size < ACLINT_MTIMER_SIZE) ||
+ (mt->first_hartid >= SBI_HARTMASK_MAX_BITS) ||
+ (mt->hart_count > ACLINT_MTIMER_MAX_HARTS))
+ return SBI_EINVAL;
+
+ /* Initialize private data */
+ mt->time_delta_reference = reference;
+ mt->time_delta_computed = 0;
+ mt->time_delta = 0;
+ mt->time_rd = mtimer_time_rd32;
+ mt->time_wr = mtimer_time_wr32;
+
+ /* Override read/write accessors for 64bit MMIO */
+#if __riscv_xlen != 32
+ if (mt->has_64bit_mmio) {
+ mt->time_rd = mtimer_time_rd64;
+ mt->time_wr = mtimer_time_wr64;
+ }
+#endif
+
+ /* Update MTIMER hartid table */
+ for (i = 0; i < mt->hart_count; i++)
+ mtimer_hartid2data[mt->first_hartid + i] = mt;
+
+ /* Add MTIMER regions to the root domain */
+ for (pos = 0; pos < mt->size; pos += ACLINT_MTIMER_ALIGN) {
+ region_size = ((mt->size - pos) < ACLINT_MTIMER_ALIGN) ?
+ (mt->size - pos) : ACLINT_MTIMER_ALIGN;
+ sbi_domain_memregion_init(mt->addr + pos, region_size,
+ SBI_DOMAIN_MEMREGION_MMIO, ®);
+ rc = sbi_domain_root_add_memregion(®);
+ if (rc)
+ return rc;
+ }
+
+ sbi_timer_set_device(&mtimer);
+
+ return 0;
+}
diff --git a/lib/utils/timer/objects.mk b/lib/utils/timer/objects.mk
index 1b84e92..f8e3931 100644
--- a/lib/utils/timer/objects.mk
+++ b/lib/utils/timer/objects.mk
@@ -9,3 +9,4 @@
libsbiutils-objs-y += timer/fdt_timer.o
libsbiutils-objs-y += timer/fdt_timer_clint.o
+libsbiutils-objs-y += timer/aclint_mtimer.o
--
2.25.1
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