diff mbox series

[1/6] lib: utils/timer: Add ACLINT MTIMER library

Message ID 20210612160321.330638-2-anup.patel@wdc.com
State Superseded
Headers show
Series RISC-V ACLINT Support | expand

Commit Message

Anup Patel June 12, 2021, 4:03 p.m. UTC
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@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

Comments

Bin Meng June 14, 2021, 1:04 p.m. UTC | #1
On Sun, Jun 13, 2021 at 12:04 AM Anup Patel <anup.patel@wdc.com> wrote:
>
> 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@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@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@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, &reg);
> +               rc = sbi_domain_root_add_memregion(&reg);
> +               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

nits: insert this by following the alphabetical order

Otherwise,
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Xiang W June 14, 2021, 2:47 p.m. UTC | #2
在 2021-06-12星期六的 21:33 +0530,Anup Patel写道:
> 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@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@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@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);
I recommend writing like this
	writel_relaxed(0, (void *)(addr));
	writel_relaxed(value >> 32, (void *)(addr) + 0x04);
	writel_relaxed(value & mask, (void *)(addr));

Reviewed-by: Xiang W <wxjstz@126.com>
> +}
> +
> +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,
> &reg);
> +               rc = sbi_domain_root_add_memregion(&reg);
> +               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
> 
>
Anup Patel June 23, 2021, 5:01 a.m. UTC | #3
On Mon, Jun 14, 2021 at 6:34 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> On Sun, Jun 13, 2021 at 12:04 AM Anup Patel <anup.patel@wdc.com> wrote:
> >
> > 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@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@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@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, &reg);
> > +               rc = sbi_domain_root_add_memregion(&reg);
> > +               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
>
> nits: insert this by following the alphabetical order

Okay, will update.

>
> Otherwise,
> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

Regards,
Anup
Anup Patel June 23, 2021, 5:05 a.m. UTC | #4
On Mon, Jun 14, 2021 at 8:17 PM Xiang W <wxjstz@126.com> wrote:
>
> 在 2021-06-12星期六的 21:33 +0530,Anup Patel写道:
> > 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@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@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@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);
> I recommend writing like this
>         writel_relaxed(0, (void *)(addr));
>         writel_relaxed(value >> 32, (void *)(addr) + 0x04);
>         writel_relaxed(value & mask, (void *)(addr));

Yes, certainly this is more appropriate sequence but the
RISC-V privilege spec says to write -1U instead of 0 in
the first write.

Refer, "section 3.2.1 Machine Timer Registers (mtime and
mtimecmp)" in the RISC-V privilege spec.

>
> Reviewed-by: Xiang W <wxjstz@126.com>

Regards,
Anup

> > +}
> > +
> > +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,
> > &reg);
> > +               rc = sbi_domain_root_add_memregion(&reg);
> > +               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
> >
> >
>
>
Xiang W June 23, 2021, 8:47 a.m. UTC | #5
在 2021-06-23星期三的 10:35 +0530,Anup Patel写道:
> On Mon, Jun 14, 2021 at 8:17 PM Xiang W <wxjstz@126.com> wrote:
> > 
> > 在 2021-06-12星期六的 21:33 +0530,Anup Patel写道:
> > > 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@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@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@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);
> > I recommend writing like this
> >         writel_relaxed(0, (void *)(addr));
> >         writel_relaxed(value >> 32, (void *)(addr) + 0x04);
> >         writel_relaxed(value & mask, (void *)(addr));
> 
> Yes, certainly this is more appropriate sequence but the
> RISC-V privilege spec says to write -1U instead of 0 in
> the first write.
> 
> Refer, "section 3.2.1 Machine Timer Registers (mtime and
> mtimecmp)" in the RISC-V privilege spec.
> 
Low 32bit write 0 is to prevent low 32bit carry to high 32bit. Write -1
will make this situation easier

Regards,
Xiang W
> > 
> > Reviewed-by: Xiang W <wxjstz@126.com>
> 
> Regards,
> Anup
> 
> > > +}
> > > +
> > > +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,
> > > &reg);
> > > +               rc = sbi_domain_root_add_memregion(&reg);
> > > +               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
> > > 
> > > 
> > 
> >
Xiang W June 23, 2021, 9:06 a.m. UTC | #6
在 2021-06-23星期三的 10:35 +0530,Anup Patel写道:
> On Mon, Jun 14, 2021 at 8:17 PM Xiang W <wxjstz@126.com> wrote:
> > 
> > 在 2021-06-12星期六的 21:33 +0530,Anup Patel写道:
> > > 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@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@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@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);
> > I recommend writing like this
> >         writel_relaxed(0, (void *)(addr));
> >         writel_relaxed(value >> 32, (void *)(addr) + 0x04);
> >         writel_relaxed(value & mask, (void *)(addr));
> 
> Yes, certainly this is more appropriate sequence but the
> RISC-V privilege spec says to write -1U instead of 0 in
> the first write.
> 
> Refer, "section 3.2.1 Machine Timer Registers (mtime and
> mtimecmp)" in the RISC-V privilege spec.
> 
The example in the manual is to prevent MTIMECMP from less than the
original value or less than the value to be written. And MTIMECMP is
not a counter and does not change. My suggestion is to prevent changes
during write, causing the value of the counter and expected
inconsistency after writing completion.

Regards,
Xiang W
> > 
> > Reviewed-by: Xiang W <wxjstz@126.com>
> 
> Regards,
> Anup
> 
> > > +}
> > > +
> > > +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,
> > > &reg);
> > > +               rc = sbi_domain_root_add_memregion(&reg);
> > > +               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
> > > 
> > > 
> > 
> >
Anup Patel June 24, 2021, 3:56 a.m. UTC | #7
On Wed, Jun 23, 2021 at 2:36 PM Xiang W <wxjstz@126.com> wrote:
>
> 在 2021-06-23星期三的 10:35 +0530,Anup Patel写道:
> > On Mon, Jun 14, 2021 at 8:17 PM Xiang W <wxjstz@126.com> wrote:
> > >
> > > 在 2021-06-12星期六的 21:33 +0530,Anup Patel写道:
> > > > 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@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@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@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);
> > > I recommend writing like this
> > >         writel_relaxed(0, (void *)(addr));
> > >         writel_relaxed(value >> 32, (void *)(addr) + 0x04);
> > >         writel_relaxed(value & mask, (void *)(addr));
> >
> > Yes, certainly this is more appropriate sequence but the
> > RISC-V privilege spec says to write -1U instead of 0 in
> > the first write.
> >
> > Refer, "section 3.2.1 Machine Timer Registers (mtime and
> > mtimecmp)" in the RISC-V privilege spec.
> >
> The example in the manual is to prevent MTIMECMP from less than the
> original value or less than the value to be written. And MTIMECMP is
> not a counter and does not change. My suggestion is to prevent changes
> during write, causing the value of the counter and expected
> inconsistency after writing completion.

Yes, the RISC-V privilege spec sequence is for MTIMECMP and
we need to do things differently for MTIME.

Regards,
Anup

>
> Regards,
> Xiang W
> > >
> > > Reviewed-by: Xiang W <wxjstz@126.com>
> >
> > Regards,
> > Anup
> >
> > > > +}
> > > > +
> > > > +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,
> > > > &reg);
> > > > +               rc = sbi_domain_root_add_memregion(&reg);
> > > > +               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
> > > >
> > > >
> > >
> > >
>
>
diff mbox series

Patch

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@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@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, &reg);
+		rc = sbi_domain_root_add_memregion(&reg);
+		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