[PATCH 1/4] drm/amdgpu: Introduce gfx software ring(v3)

Zhu, Jiadong Jiadong.Zhu at amd.com
Tue Sep 13 01:44:00 UTC 2022


[AMD Official Use Only - General]

-----Original Message-----
From: Grodzovsky, Andrey <Andrey.Grodzovsky at amd.com>
Sent: Tuesday, September 13, 2022 12:45 AM
To: Christian König <ckoenig.leichtzumerken at gmail.com>; Zhu, Jiadong <Jiadong.Zhu at amd.com>; amd-gfx at lists.freedesktop.org
Cc: Huang, Ray <Ray.Huang at amd.com>
Subject: Re: [PATCH 1/4] drm/amdgpu: Introduce gfx software ring(v3)


On 2022-09-12 12:22, Christian König wrote:
> Am 12.09.22 um 17:34 schrieb Andrey Grodzovsky:
>> On 2022-09-12 09:27, Christian König wrote:
>>
>>> Am 12.09.22 um 15:22 schrieb Andrey Grodzovsky:
>>>>
>>>> On 2022-09-12 06:20, Christian König wrote:
>>>>> Am 09.09.22 um 18:45 schrieb Andrey Grodzovsky:
>>>>>>
>>>>>> On 2022-09-08 21:50, jiadong.zhu at amd.com wrote:
>>>>>>> From: "Jiadong.Zhu" <Jiadong.Zhu at amd.com>
>>>>>>>
>>>>>>> The software ring is created to support priority context while
>>>>>>> there is only one hardware queue for gfx.
>>>>>>>
>>>>>>> Every software rings has its fence driver and could be used as
>>>>>>> an ordinary ring for the gpu_scheduler.
>>>>>>> Multiple software rings are binded to a real ring with the ring
>>>>>>> muxer. The packages committed on the software ring are copied to
>>>>>>> the real ring.
>>>>>>>
>>>>>>> v2: use array to store software ring entry.
>>>>>>> v3: remove unnecessary prints.
>>>>>>>
>>>>>>> Signed-off-by: Jiadong.Zhu <Jiadong.Zhu at amd.com>
>>>>>>> ---
>>>>>>>   drivers/gpu/drm/amd/amdgpu/Makefile          |   3 +-
>>>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h      |   3 +
>>>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h     |   3 +
>>>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c | 182
>>>>>>> +++++++++++++++++
>>>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.h |  67 ++++++
>>>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.c  | 204
>>>>>>> +++++++++++++++++++
>>>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.h  |  48 +++++
>>>>>>>   7 files changed, 509 insertions(+), 1 deletion(-)
>>>>>>>   create mode 100644
>>>>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c
>>>>>>>   create mode 100644
>>>>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.h
>>>>>>>   create mode 100644 drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.c
>>>>>>>   create mode 100644 drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.h
>>>>>>>
>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile
>>>>>>> b/drivers/gpu/drm/amd/amdgpu/Makefile
>>>>>>> index 3e0e2eb7e235..85224bc81ce5 100644
>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/Makefile
>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/Makefile
>>>>>>> @@ -58,7 +58,8 @@ amdgpu-y += amdgpu_device.o amdgpu_kms.o \
>>>>>>>       amdgpu_vm_sdma.o amdgpu_discovery.o amdgpu_ras_eeprom.o
>>>>>>> amdgpu_nbio.o \
>>>>>>>       amdgpu_umc.o smu_v11_0_i2c.o amdgpu_fru_eeprom.o
>>>>>>> amdgpu_rap.o \
>>>>>>>       amdgpu_fw_attestation.o amdgpu_securedisplay.o \
>>>>>>> -    amdgpu_eeprom.o amdgpu_mca.o amdgpu_psp_ta.o amdgpu_lsdma.o
>>>>>>> +    amdgpu_eeprom.o amdgpu_mca.o amdgpu_psp_ta.o amdgpu_lsdma.o
>>>>>>> +\
>>>>>>> +    amdgpu_sw_ring.o amdgpu_ring_mux.o
>>>>>>>     amdgpu-$(CONFIG_PROC_FS) += amdgpu_fdinfo.o
>>>>>>>   diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
>>>>>>> index 53526ffb2ce1..0de8e3cd0f1c 100644
>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
>>>>>>> @@ -33,6 +33,7 @@
>>>>>>>   #include "amdgpu_imu.h"
>>>>>>>   #include "soc15.h"
>>>>>>>   #include "amdgpu_ras.h"
>>>>>>> +#include "amdgpu_ring_mux.h"
>>>>>>>     /* GFX current status */
>>>>>>>   #define AMDGPU_GFX_NORMAL_MODE 0x00000000L @@ -346,6 +347,8 @@
>>>>>>> struct amdgpu_gfx {
>>>>>>>       struct amdgpu_gfx_ras        *ras;
>>>>>>>         bool                is_poweron;
>>>>>>> +
>>>>>>> +    struct amdgpu_ring_mux            muxer;
>>>>>>>   };
>>>>>>>     #define amdgpu_gfx_get_gpu_clock_counter(adev)
>>>>>>> (adev)->gfx.funcs->get_gpu_clock_counter((adev))
>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
>>>>>>> index 7d89a52091c0..fe33a683bfba 100644
>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
>>>>>>> @@ -278,6 +278,9 @@ struct amdgpu_ring {
>>>>>>>       bool            is_mes_queue;
>>>>>>>       uint32_t        hw_queue_id;
>>>>>>>       struct amdgpu_mes_ctx_data *mes_ctx;
>>>>>>> +
>>>>>>> +    bool            is_sw_ring;
>>>>>>> +
>>>>>>>   };
>>>>>>>     #define amdgpu_ring_parse_cs(r, p, job, ib)
>>>>>>> ((r)->funcs->parse_cs((p), (job), (ib))) diff --git
>>>>>>> a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c
>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c
>>>>>>> new file mode 100644
>>>>>>> index 000000000000..ea4a3c66119a
>>>>>>> --- /dev/null
>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c
>>>>>>> @@ -0,0 +1,182 @@
>>>>>>> +/*
>>>>>>> + * Copyright 2022 Advanced Micro Devices, Inc.
>>>>>>> + *
>>>>>>> + * Permission is hereby granted, free of charge, to any person
>>>>>>> obtaining a
>>>>>>> + * copy of this software and associated documentation files
>>>>>>> (the "Software"),
>>>>>>> + * to deal in the Software without restriction, including
>>>>>>> without limitation
>>>>>>> + * the rights to use, copy, modify, merge, publish, distribute,
>>>>>>> sublicense,
>>>>>>> + * and/or sell copies of the Software, and to permit persons to
>>>>>>> whom the
>>>>>>> + * Software is furnished to do so, subject to the following
>>>>>>> conditions:
>>>>>>> + *
>>>>>>> + * The above copyright notice and this permission notice shall
>>>>>>> be included in
>>>>>>> + * all copies or substantial portions of the Software.
>>>>>>> + *
>>>>>>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
>>>>>>> KIND, EXPRESS OR
>>>>>>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
>>>>>>> MERCHANTABILITY,
>>>>>>> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO
>>>>>>> EVENT SHALL
>>>>>>> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY
>>>>>>> CLAIM, DAMAGES OR
>>>>>>> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
>>>>>>> OTHERWISE,
>>>>>>> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
>>>>>>> THE USE OR
>>>>>>> + * OTHER DEALINGS IN THE SOFTWARE.
>>>>>>> + *
>>>>>>> + */
>>>>>>> +
>>>>>>> +#include <drm/drm_print.h>
>>>>>>> +
>>>>>>> +#include "amdgpu_ring_mux.h"
>>>>>>> +#include "amdgpu_ring.h"
>>>>>>> +
>>>>>>> +#define AMDGPU_MUX_RESUBMIT_JIFFIES_TIMEOUT (HZ/2)
>>>>>>> +
>>>>>>> +static int copy_pkt_from_sw_ring(struct amdgpu_ring_mux *mux,
>>>>>>> struct amdgpu_ring *ring,
>>>>>>> +    u64 s_begin, u64 s_end);
>>>>>>> +
>>>>>>> +int amdgpu_ring_mux_init(struct amdgpu_ring_mux *mux, struct
>>>>>>> amdgpu_ring *ring)
>>>>>>> +{
>>>>>>> +    mux->real_ring = ring;
>>>>>>> +    memset(mux->ring_entries, 0, sizeof(mux->ring_entries));
>>>>>>> +    mux->num_ring_entries = 0;
>>>>>>> +    spin_lock_init(&mux->lock);
>>>>>>> +    return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +void amdgpu_ring_mux_fini(struct amdgpu_ring_mux *mux) {
>>>>>>> +    memset(mux->ring_entries, 0, sizeof(mux->ring_entries));
>>>>>>> +    mux->num_ring_entries = 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +int amdgpu_ring_mux_add_sw_ring(struct amdgpu_ring_mux *mux,
>>>>>>> struct amdgpu_ring *ring)
>>>>>>> +{
>>>>>>> +    struct amdgpu_mux_entry *e;
>>>>>>> +
>>>>>>> +    if (mux->num_ring_entries == AMDGPU_MAX_GFX_RINGS) {
>>>>>>> +        DRM_ERROR("adding sw ring exceeds max gfx num\n");
>>>>>>> +        return -ENOMEM;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    e = &mux->ring_entries[mux->num_ring_entries++];
>>>>>>> +
>>>>>>> +    e->ring = ring;
>>>>>>> +    e->start_ptr_in_hw_ring = 0;
>>>>>>> +    e->end_ptr_in_hw_ring = 0;
>>>>>>> +    e->sw_cptr = 0;
>>>>>>> +    e->sw_rptr = 0;
>>>>>>> +    e->sw_wptr = 0;
>>>>>>> +
>>>>>>> +    return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +static struct amdgpu_mux_entry *amdgpu_get_sw_entry(struct
>>>>>>> amdgpu_ring_mux *mux,
>>>>>>> +                struct amdgpu_ring *ring) {
>>>>>>> +    struct amdgpu_mux_entry *e;
>>>>>>> +    int i;
>>>>>>> +
>>>>>>> +    e = NULL;
>>>>>>> +    for (i = 0; i < mux->num_ring_entries; i++) {
>>>>>>> +        if (mux->ring_entries[i].ring == ring) {
>>>>>>> +            e = &mux->ring_entries[i];
>>>>>>> +            break;
>>>>>>> +        }
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    return e;
>>>>>>> +}
>>>>>>> +
>>>>>>> +void amdgpu_ring_set_wptr_to_mux(struct amdgpu_ring_mux *mux,
>>>>>>> struct amdgpu_ring *ring, u64 wptr)
>>>>>>> +{
>>>>>>> +    struct amdgpu_mux_entry *e;
>>>>>>> +
>>>>>>> +    e = amdgpu_get_sw_entry(mux, ring);
>>>>>>> +    if (!e) {
>>>>>>> +        DRM_ERROR("cannot find entry for sw ring\n");
>>>>>>> +        return;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    spin_lock(&mux->lock);
>>>>>>
>>>>>>
>>>>>> A bit more generic question, I assume the spinlock here protects
>>>>>> from concurrent runs of amdgpu_ib_schedule. For them to be even
>>>>>> theoretically concurrent it must be from direct submissions to HW
>>>>>> (because any scheduler mediated submission is serialized though
>>>>>> the dedicated scheduler worker thread). But in such case why we
>>>>>> protect only here ? If i am not missing something there is no
>>>>>> total per HW ring lock when calling amdgpu_ib_schedule today and
>>>>>> we do a lot of HW accesses there to ring  which should probably
>>>>>> be protected from concurrent accesses.
>>>>>>
>>>>>> So if any one can answer this question ?
>>>>>
>>>>> Well what we have is in general two schedulers which push their
>>>>> work into one hardware ring.
>>>>>
>>>>> So we need a lock to make sure that only one is modifying the hw
>>>>> ring at the same time.
>>>>>
>>>>> From the implementation I think we first write the commands into a
>>>>> shadow ring buffer and then copy them over to the real hw ring here.
>>>>>
>>>>> So this is the only place where we actually touch the hw ring
>>>>> buffer and to need to grab the lock.
>>>>>
>>>>> Did I get this right?
>>>>>
>>>>> Thanks,
>>>>> Christian.
>>>>
>>>>
>>>> For the case of the sw ring yes, but I was asking in general,
>>>> accesses to real HW rings, amdgpu_ib_schedule writes to HW rings,
>>>> we may be accessing same HW ring from 2 different contexts when
>>>> doing direct submissions (i.e. calling amdgpu_ib_schedule directly
>>>> from 2 threads concurrently) this opens possibility to concurrent
>>>> access to HW. Or am i missing something here ?
>>>
>>> No, that's pretty much correct.
>>>
>>> The general idea is that amdgpu_ib_schedule() first writes into a
>>> separate software ring buffer for each scheduler. So no locking
>>> needed for that.
>>>
>>> Then when the set_wptr callback is called we grab the lock and copy
>>> the software ring content to the real hw ring and telling the hw to
>>> execute it.
>>>
>>> The spin_lock is to protect from concurrent hw access.
>>>
>>> Regards,
>>> Christian.
>>
>>
>> Look at
>> amdgpu_copy_buffer->amdgpu_job_submit_direct->amdgpu_ib_schedule->amd
>> gpu_ring_commit->amdgpu_ring_set_wptr,
>> at no point there lock is taken. The only lock i see that resembles
>> what you describe is for amdgpu_kiq.ring_lock. So this applies only
>> to some of the code but not to all cases.
>
> Sounds like we have a misunderstanding here.
>
> The case we look at should be this:
>
> amdgpu_job_run()->amdgpu_ib_schedule()->amdgpu_ring_commit()->amdgpu_r
> ing_set_wptr()...amdgpu_ring_set_wptr_to_mux()
>
>
> Then amdgpu_ring_set_wptr_to_mux() we then grab the lock, copy over
> the commands, commit them to the hw and then drop the lock.


> Yes, misunderstanding - I am asking for the general case not related to this patch-set. When we work with HW rings directly from direct submissions.
> Nothing prevents in that case from 2 concurrent accesses to HW the way i showed above, or is there something ?

> Andrey

drm_sched_init creates the thread of drm_sched_main once per ring, thus every amdgpu_ib_schedule on a certain ring should be executed in the same thread. Please correct me if I am wrong.

Thanks,
Jiadong
>
> Christian.
>
>>
>> Andrey
>>
>>
>>>
>>>
>>>>
>>>> Andrey
>>>>
>>>>
>>>>>
>>>>>>
>>>>>>
>>>>>>> +    e->sw_cptr = e->sw_wptr;
>>>>>>> +    e->sw_wptr = wptr;
>>>>>>> +    e->start_ptr_in_hw_ring = mux->real_ring->wptr;
>>>>>>> +
>>>>>>> +    if (copy_pkt_from_sw_ring(mux, ring, e->sw_cptr, wptr) ==
>>>>>>> +0) {
>>>>>>> +        e->end_ptr_in_hw_ring = mux->real_ring->wptr;
>>>>>>> +        amdgpu_ring_commit(mux->real_ring);
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    spin_unlock(&mux->lock);
>>>>>>> +}
>>>>>>> +
>>>>>>> +u64 amdgpu_ring_get_wptr_from_mux(struct amdgpu_ring_mux *mux,
>>>>>>> struct amdgpu_ring *ring)
>>>>>>> +{
>>>>>>> +    struct amdgpu_mux_entry *e;
>>>>>>> +
>>>>>>> +    e = amdgpu_get_sw_entry(mux, ring);
>>>>>>> +    if (!e) {
>>>>>>> +        DRM_ERROR("cannot find entry for sw ring\n");
>>>>>>> +        return 0;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    return e->sw_wptr;
>>>>>>> +}
>>>>>>> +
>>>>>>> +u64 amdgpu_ring_get_rptr_from_mux(struct amdgpu_ring_mux *mux,
>>>>>>> struct amdgpu_ring *ring)
>>>>>>> +{
>>>>>>> +    struct amdgpu_mux_entry *e;
>>>>>>> +    u64 r_rptr, r_wptr, offset, start, end;
>>>>>>> +
>>>>>>> +    e = amdgpu_get_sw_entry(mux, ring);
>>>>>>> +    if (!e) {
>>>>>>> +        DRM_ERROR("no sw entry found!\n");
>>>>>>> +        return 0;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    r_rptr = amdgpu_ring_get_rptr(mux->real_ring);
>>>>>>> +    r_wptr = amdgpu_ring_get_wptr(mux->real_ring);
>>>>>>> +
>>>>>>> +    if (r_wptr < r_rptr)
>>>>>>> +        r_wptr += mux->real_ring->ring_size >> 2;
>>>>>>> +
>>>>>>> +    start = e->start_ptr_in_hw_ring & mux->real_ring->buf_mask;
>>>>>>> +    end = e->end_ptr_in_hw_ring & mux->real_ring->buf_mask;
>>>>>>> +    if (start > end)
>>>>>>> +        end += mux->real_ring->ring_size >> 2;
>>>>>>> +    if (r_rptr <= end && r_rptr >= start) {
>>>>>>> +        offset = r_rptr - start;
>>>>>>> +        e->sw_rptr = (e->sw_cptr + offset) & ring->buf_mask;
>>>>>>> +    } else if (r_rptr < start) {
>>>>>>> +        e->sw_rptr = e->sw_cptr;
>>>>>>> +    } else {
>>>>>>> +        e->sw_rptr = e->sw_wptr;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    return e->sw_rptr;
>>>>>>> +}
>>>>>>> +
>>>>>>> +/*copy packages on sw ring range[begin, end) */ static int
>>>>>>> +copy_pkt_from_sw_ring(struct amdgpu_ring_mux *mux,
>>>>>>> struct amdgpu_ring *ring,
>>>>>>> +    u64 s_begin, u64 s_end)
>>>>>>> +{
>>>>>>> +    u64 begin, end, r_begin, r_end;
>>>>>>> +    struct amdgpu_ring *real_ring = mux->real_ring;
>>>>>>> +
>>>>>>> +    begin = s_begin & ring->buf_mask;
>>>>>>> +    end = s_end & ring->buf_mask;
>>>>>>> +
>>>>>>> +    r_begin = real_ring->wptr & real_ring->buf_mask;
>>>>>>> +    if (begin == end)
>>>>>>> +        return -ERANGE;
>>>>>>> +    if (begin > end) {
>>>>>>> +        amdgpu_ring_alloc(real_ring, (ring->ring_size >> 2) +
>>>>>>> end - begin);
>>>>>>> +        amdgpu_ring_write_multiple(real_ring, (void
>>>>>>> *)&ring->ring[begin],
>>>>>>> +            (ring->ring_size >> 2) - begin);
>>>>>>> +        amdgpu_ring_write_multiple(real_ring, (void
>>>>>>> *)&ring->ring[0], end);
>>>>>>> +    } else {
>>>>>>> +        amdgpu_ring_alloc(real_ring, end - begin);
>>>>>>> +        amdgpu_ring_write_multiple(real_ring, (void
>>>>>>> *)&ring->ring[begin], end - begin);
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    r_end = real_ring->wptr & real_ring->buf_mask;
>>>>>>> +
>>>>>>> +    return 0;
>>>>>>> +}
>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.h
>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.h
>>>>>>> new file mode 100644
>>>>>>> index 000000000000..d058c43bb063
>>>>>>> --- /dev/null
>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.h
>>>>>>> @@ -0,0 +1,67 @@
>>>>>>> +/*
>>>>>>> + * Copyright 2022 Advanced Micro Devices, Inc.
>>>>>>> + *
>>>>>>> + * Permission is hereby granted, free of charge, to any person
>>>>>>> obtaining a
>>>>>>> + * copy of this software and associated documentation files
>>>>>>> (the "Software"),
>>>>>>> + * to deal in the Software without restriction, including
>>>>>>> without limitation
>>>>>>> + * the rights to use, copy, modify, merge, publish, distribute,
>>>>>>> sublicense,
>>>>>>> + * and/or sell copies of the Software, and to permit persons to
>>>>>>> whom the
>>>>>>> + * Software is furnished to do so, subject to the following
>>>>>>> conditions:
>>>>>>> + *
>>>>>>> + * The above copyright notice and this permission notice shall
>>>>>>> be included in
>>>>>>> + * all copies or substantial portions of the Software.
>>>>>>> + *
>>>>>>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
>>>>>>> KIND, EXPRESS OR
>>>>>>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
>>>>>>> MERCHANTABILITY,
>>>>>>> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO
>>>>>>> EVENT SHALL
>>>>>>> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY
>>>>>>> CLAIM, DAMAGES OR
>>>>>>> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
>>>>>>> OTHERWISE,
>>>>>>> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
>>>>>>> THE USE OR
>>>>>>> + * OTHER DEALINGS IN THE SOFTWARE.
>>>>>>> + *
>>>>>>> + */
>>>>>>> +
>>>>>>> +#ifndef __AMDGPU_RING_MUX__
>>>>>>> +#define __AMDGPU_RING_MUX__
>>>>>>> +
>>>>>>> +#include <linux/timer.h>
>>>>>>> +#include <linux/spinlock.h>
>>>>>>> +#include "amdgpu_ring.h"
>>>>>>> +
>>>>>>> +struct amdgpu_ring;
>>>>>>> +/*
>>>>>>> + * start_ptr_in_hw_ring - last copied start loc on hw ring
>>>>>>> + * end_ptr_in_hw_ring - last copied end loc on hw ring
>>>>>>> +*sw_cptr -the begin of copy ptr in sw ring  *sw_rptr; the read
>>>>>>> +ptr in sw ring  *sw_wptr; the write ptr in sw ring  */ struct
>>>>>>> +amdgpu_mux_entry {
>>>>>>> +    struct amdgpu_ring    *ring;
>>>>>>> +    u64 start_ptr_in_hw_ring;
>>>>>>> +    u64 end_ptr_in_hw_ring;
>>>>>>> +
>>>>>>> +    u64 sw_cptr;
>>>>>>> +    u64 sw_rptr;
>>>>>>> +    u64 sw_wptr;
>>>>>>> +};
>>>>>>> +
>>>>>>> +struct amdgpu_ring_mux {
>>>>>>> +    struct amdgpu_ring *real_ring;
>>>>>>> +
>>>>>>> +    struct amdgpu_mux_entry ring_entries[AMDGPU_MAX_GFX_RINGS];
>>>>>>> +
>>>>>>> +    unsigned num_ring_entries;
>>>>>>> +
>>>>>>> +    spinlock_t            lock;
>>>>>>> +
>>>>>>> +};
>>>>>>> +
>>>>>>> +int amdgpu_ring_mux_init(struct amdgpu_ring_mux *mux, struct
>>>>>>> amdgpu_ring *ring);
>>>>>>> +void amdgpu_ring_mux_fini(struct amdgpu_ring_mux *mux); int
>>>>>>> +amdgpu_ring_mux_add_sw_ring(struct amdgpu_ring_mux *mux,
>>>>>>> struct amdgpu_ring *ring);
>>>>>>> +void amdgpu_ring_set_wptr_to_mux(struct amdgpu_ring_mux *mux,
>>>>>>> struct amdgpu_ring *ring, u64 wptr);
>>>>>>> +u64 amdgpu_ring_get_wptr_from_mux(struct amdgpu_ring_mux *mux,
>>>>>>> struct amdgpu_ring *ring);
>>>>>>> +u64 amdgpu_ring_get_rptr_from_mux(struct amdgpu_ring_mux *mux,
>>>>>>> struct amdgpu_ring *ring);
>>>>>>> +
>>>>>>> +#endif
>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.c
>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.c
>>>>>>> new file mode 100644
>>>>>>> index 000000000000..452d0ff37758
>>>>>>> --- /dev/null
>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.c
>>>>>>> @@ -0,0 +1,204 @@
>>>>>>> +/*
>>>>>>> + * Copyright 2022 Advanced Micro Devices, Inc.
>>>>>>> + * All Rights Reserved.
>>>>>>> + *
>>>>>>> + * Permission is hereby granted, free of charge, to any person
>>>>>>> obtaining a
>>>>>>> + * copy of this software and associated documentation files
>>>>>>> + (the
>>>>>>> + * "Software"), to deal in the Software without restriction,
>>>>>>> including
>>>>>>> + * without limitation the rights to use, copy, modify, merge,
>>>>>>> publish,
>>>>>>> + * distribute, sub license, and/or sell copies of the Software,
>>>>>>> and to
>>>>>>> + * permit persons to whom the Software is furnished to do so,
>>>>>>> subject to
>>>>>>> + * the following conditions:
>>>>>>> + *
>>>>>>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
>>>>>>> KIND, EXPRESS OR
>>>>>>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
>>>>>>> MERCHANTABILITY,
>>>>>>> + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO
>>>>>>> EVENT SHALL
>>>>>>> + * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE
>>>>>>> LIABLE FOR ANY CLAIM,
>>>>>>> + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
>>>>>>> CONTRACT, TORT OR
>>>>>>> + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
>>>>>>> SOFTWARE OR THE
>>>>>>> + * USE OR OTHER DEALINGS IN THE SOFTWARE.
>>>>>>> + *
>>>>>>> + * The above copyright notice and this permission notice
>>>>>>> (including the
>>>>>>> + * next paragraph) shall be included in all copies or
>>>>>>> substantial portions
>>>>>>> + * of the Software.
>>>>>>> + *
>>>>>>> + */
>>>>>>> +
>>>>>>> +#include "amdgpu_sw_ring.h"
>>>>>>> +#include "amdgpu_ring_mux.h"
>>>>>>> +
>>>>>>> +#define amdgpu_ring_get_gpu_addr(ring, offset) \
>>>>>>> +    (ring->is_mes_queue ?                        \
>>>>>>> +     (ring->mes_ctx->meta_data_gpu_addr + offset) :
>>>>>>> +\
>>>>>>> +     (ring->adev->wb.gpu_addr + offset * 4))
>>>>>>> +
>>>>>>> +#define amdgpu_ring_get_cpu_addr(ring, offset) \
>>>>>>> +    (ring->is_mes_queue ?                        \
>>>>>>> +     (void *)((uint8_t *)(ring->mes_ctx->meta_data_ptr) +
>>>>>>> offset) : \
>>>>>>> +     (&ring->adev->wb.wb[offset]))
>>>>>>> +
>>>>>>> +
>>>>>>> +int amdgpu_sw_ring_init(struct amdgpu_device *adev, struct
>>>>>>> amdgpu_ring *ring,
>>>>>>> +             unsigned int max_dw, struct amdgpu_irq_src
>>>>>>> +*irq_src,
>>>>>>> +             unsigned int irq_type, unsigned int hw_prio,
>>>>>>> +             atomic_t *sched_score) {
>>>>>>> +    int r;
>>>>>>> +    int sched_hw_submission = amdgpu_sched_hw_submission;
>>>>>>> +    u32 *num_sched;
>>>>>>> +    u32 hw_ip;
>>>>>>> +
>>>>>>> +    BUG_ON(!ring->is_sw_ring);
>>>>>>> +
>>>>>>> +    if (ring->adev == NULL) {
>>>>>>> +        if (adev->num_rings >= AMDGPU_MAX_RINGS)
>>>>>>> +            return -EINVAL;
>>>>>>> +
>>>>>>> +        ring->adev = adev;
>>>>>>> +        ring->num_hw_submission = sched_hw_submission;
>>>>>>> +        ring->sched_score = sched_score;
>>>>>>> +        ring->vmid_wait = dma_fence_get_stub();
>>>>>>> +
>>>>>>> +        if (!ring->is_mes_queue) {
>>>>>>> +            ring->idx = adev->num_rings++;
>>>>>>> +            adev->rings[ring->idx] = ring;
>>>>>>> +        }
>>>>>>> +
>>>>>>> +        r = amdgpu_fence_driver_init_ring(ring);
>>>>>>> +        if (r)
>>>>>>> +            return r;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    r = amdgpu_device_wb_get(adev, &ring->fence_offs);
>>>>>>> +    if (r) {
>>>>>>> +        dev_err(adev->dev, "(%d) ring fence_offs wb alloc
>>>>>>> failed\n", r);
>>>>>>> +        return r;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    r = amdgpu_device_wb_get(adev, &ring->fence_offs);
>>>>>>> +    if (r) {
>>>>>>> +        dev_err(adev->dev, "(%d) ring fence_offs wb alloc
>>>>>>> failed\n", r);
>>>>>>> +        return r;
>>>>>>> +    }
>>>>>>
>>>>>>
>>>>>> Looks like a typo copy pase duplicate of the above
>>>>>>
>>>>>>> +
>>>>>>> +    r = amdgpu_device_wb_get(adev, &ring->trail_fence_offs);
>>>>>>> +    if (r) {
>>>>>>> +        dev_err(adev->dev, "(%d) ring trail_fence_offs wb alloc
>>>>>>> failed\n", r);
>>>>>>> +        return r;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    r = amdgpu_device_wb_get(adev, &ring->cond_exe_offs);
>>>>>>> +    if (r) {
>>>>>>> +        dev_err(adev->dev, "(%d) ring cond_exec_polling wb
>>>>>>> alloc failed\n", r);
>>>>>>> +        return r;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    ring->fence_gpu_addr =
>>>>>>> +        amdgpu_ring_get_gpu_addr(ring, ring->fence_offs);
>>>>>>> +    ring->fence_cpu_addr =
>>>>>>> +        amdgpu_ring_get_cpu_addr(ring, ring->fence_offs);
>>>>>>> +
>>>>>>> +    ring->trail_fence_gpu_addr =
>>>>>>> +        amdgpu_ring_get_gpu_addr(ring, ring->trail_fence_offs);
>>>>>>> +    ring->trail_fence_cpu_addr =
>>>>>>> +        amdgpu_ring_get_cpu_addr(ring, ring->trail_fence_offs);
>>>>>>> +
>>>>>>> +    ring->cond_exe_gpu_addr =
>>>>>>> +        amdgpu_ring_get_gpu_addr(ring, ring->cond_exe_offs);
>>>>>>> +    ring->cond_exe_cpu_addr =
>>>>>>> +        amdgpu_ring_get_cpu_addr(ring, ring->cond_exe_offs);
>>>>>>> +
>>>>>>> +    /* always set cond_exec_polling to CONTINUE */
>>>>>>> +    *ring->cond_exe_cpu_addr = 1;
>>>>>>> +
>>>>>>> +    r = amdgpu_fence_driver_start_ring(ring, irq_src,
>>>>>>> +irq_type);
>>>>>>> +    if (r) {
>>>>>>> +        dev_err(adev->dev, "failed initializing fences
>>>>>>> (%d).\n", r);
>>>>>>> +        return r;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    ring->ring_size = roundup_pow_of_two(max_dw * 4 *
>>>>>>> sched_hw_submission);
>>>>>>> +
>>>>>>> +    ring->buf_mask = (ring->ring_size / 4) - 1;
>>>>>>> +    ring->ptr_mask = ring->funcs->support_64bit_ptrs ?
>>>>>>> +        0xffffffffffffffff : ring->buf_mask;
>>>>>>> +
>>>>>>> +    /* Allocate ring buffer */
>>>>>>> +    if (ring->ring == NULL) {
>>>>>>> +        ring->ring = kzalloc(ring->ring_size +
>>>>>>> ring->funcs->extra_dw, GFP_KERNEL);
>>>>>>> +        if (!ring->ring) {
>>>>>>> +            dev_err(adev->dev, "(%d) swring create failed\n",
>>>>>>> +r);
>>>>>>> +            return r;
>>>>>>> +        }
>>>>>>> +
>>>>>>> +        amdgpu_ring_clear_ring(ring);
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    ring->max_dw = max_dw;
>>>>>>> +    ring->hw_prio = hw_prio;
>>>>>>> +
>>>>>>> +    if (!ring->no_scheduler) {
>>>>>>> +        hw_ip = ring->funcs->type;
>>>>>>> +        num_sched =
>>>>>>> +&adev->gpu_sched[hw_ip][hw_prio].num_scheds;
>>>>>>> + adev->gpu_sched[hw_ip][hw_prio].sched[(*num_sched)++] =
>>>>>>> +            &ring->sched;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    return 0;
>>>>>>> +}
>>>>>>
>>>>>>
>>>>>> In general i see this function is a big one to one subset of
>>>>>> amdgpu_ring_init.
>>>>>> Could you maybe see a way to refactor such that this function is
>>>>>> the base and for HW related code that different (like BO
>>>>>> allocation for ring buffer) you maybe can add if
>>>>>> (!ring->sw_ring)... and add those code snippets ? To avoid
>>>>>> substantial code duplication.
>>>>>>
>>>>>> Andrey
>>>>>>
>>>>>>
>>>>>>> +
>>>>>>> +u64 amdgpu_sw_ring_get_rptr_gfx(struct amdgpu_ring *ring) {
>>>>>>> +    struct amdgpu_device *adev = ring->adev;
>>>>>>> +    struct amdgpu_ring_mux *mux = &adev->gfx.muxer;
>>>>>>> +
>>>>>>> +    BUG_ON(!ring->is_sw_ring);
>>>>>>> +    return amdgpu_ring_get_rptr_from_mux(mux, ring); }
>>>>>>> +
>>>>>>> +u64 amdgpu_sw_ring_get_wptr_gfx(struct amdgpu_ring *ring) {
>>>>>>> +    struct amdgpu_device *adev = ring->adev;
>>>>>>> +    struct amdgpu_ring_mux *mux = &adev->gfx.muxer;
>>>>>>> +
>>>>>>> +    BUG_ON(!ring->is_sw_ring);
>>>>>>> +    return amdgpu_ring_get_wptr_from_mux(mux, ring); }
>>>>>>> +
>>>>>>> +void amdgpu_sw_ring_set_wptr_gfx(struct amdgpu_ring *ring) {
>>>>>>> +    BUG_ON(!ring->is_sw_ring);
>>>>>>> +}
>>>>>>> +
>>>>>>> +void amdgpu_sw_ring_commit(struct amdgpu_ring *ring) {
>>>>>>> +    struct amdgpu_device *adev = ring->adev;
>>>>>>> +    struct amdgpu_ring_mux *mux = &adev->gfx.muxer;
>>>>>>> +
>>>>>>> +    BUG_ON(!ring->is_sw_ring);
>>>>>>> +    amdgpu_ring_set_wptr_to_mux(mux, ring, ring->wptr); }
>>>>>>> +
>>>>>>> +void amdgpu_sw_ring_fini(struct amdgpu_ring *ring) {
>>>>>>> +    BUG_ON(!ring->is_sw_ring);
>>>>>>> +
>>>>>>> +    /* Not to finish a ring which is not initialized */
>>>>>>> +    if (!(ring->adev) ||
>>>>>>> +        (!ring->is_mes_queue &&
>>>>>>> +!(ring->adev->rings[ring->idx])))
>>>>>>> +        return;
>>>>>>> +
>>>>>>> +    ring->sched.ready = false;
>>>>>>> +
>>>>>>> +    amdgpu_device_wb_free(ring->adev, ring->cond_exe_offs);
>>>>>>> +    amdgpu_device_wb_free(ring->adev, ring->fence_offs);
>>>>>>> +
>>>>>>> +    kfree((void *)ring->ring);
>>>>>>> +
>>>>>>> +    dma_fence_put(ring->vmid_wait);
>>>>>>> +    ring->vmid_wait = NULL;
>>>>>>> +    ring->me = 0;
>>>>>>> +
>>>>>>> +    ring->adev->rings[ring->idx] = NULL; }
>>>>>>> +
>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.h
>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.h
>>>>>>> new file mode 100644
>>>>>>> index 000000000000..c05d8a94ad0c
>>>>>>> --- /dev/null
>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.h
>>>>>>> @@ -0,0 +1,48 @@
>>>>>>> +/*
>>>>>>> + * Copyright 2012 Advanced Micro Devices, Inc.
>>>>>>> + *
>>>>>>> + * Permission is hereby granted, free of charge, to any person
>>>>>>> obtaining a
>>>>>>> + * copy of this software and associated documentation files
>>>>>>> (the "Software"),
>>>>>>> + * to deal in the Software without restriction, including
>>>>>>> without limitation
>>>>>>> + * the rights to use, copy, modify, merge, publish, distribute,
>>>>>>> sublicense,
>>>>>>> + * and/or sell copies of the Software, and to permit persons to
>>>>>>> whom the
>>>>>>> + * Software is furnished to do so, subject to the following
>>>>>>> conditions:
>>>>>>> + *
>>>>>>> + * The above copyright notice and this permission notice shall
>>>>>>> be included in
>>>>>>> + * all copies or substantial portions of the Software.
>>>>>>> + *
>>>>>>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
>>>>>>> KIND, EXPRESS OR
>>>>>>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
>>>>>>> MERCHANTABILITY,
>>>>>>> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO
>>>>>>> EVENT SHALL
>>>>>>> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY
>>>>>>> CLAIM, DAMAGES OR
>>>>>>> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
>>>>>>> OTHERWISE,
>>>>>>> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
>>>>>>> THE USE OR
>>>>>>> + * OTHER DEALINGS IN THE SOFTWARE.
>>>>>>> + *
>>>>>>> + */
>>>>>>> +
>>>>>>> +#include <drm/amdgpu_drm.h>
>>>>>>> +#include <drm/gpu_scheduler.h>
>>>>>>> +#include <drm/drm_print.h>
>>>>>>> +
>>>>>>> +#include "amdgpu_irq.h"
>>>>>>> +#include "amdgpu_ring.h"
>>>>>>> +#include "amdgpu.h"
>>>>>>> +
>>>>>>> +#ifndef __AMDGPU_SWRING_H__
>>>>>>> +#define __AMDGPU_SWRING_H__
>>>>>>> +
>>>>>>> +int amdgpu_sw_ring_init(struct amdgpu_device *adev, struct
>>>>>>> amdgpu_ring *sw_ring,
>>>>>>> +             unsigned int max_dw, struct amdgpu_irq_src
>>>>>>> +*irq_src,
>>>>>>> +             unsigned int irq_type, unsigned int hw_prio,
>>>>>>> +             atomic_t *sched_score); void
>>>>>>> +amdgpu_sw_ring_fini(struct amdgpu_ring *ring);
>>>>>>> +u64 amdgpu_sw_ring_get_rptr_gfx(struct amdgpu_ring *ring);
>>>>>>> +u64 amdgpu_sw_ring_get_wptr_gfx(struct amdgpu_ring *ring); void
>>>>>>> +amdgpu_sw_ring_set_wptr_gfx(struct amdgpu_ring *ring); void
>>>>>>> +amdgpu_sw_ring_commit(struct amdgpu_ring *ring);
>>>>>>> +
>>>>>>> +void amdgpu_sw_ring_ib_begin(struct amdgpu_ring *ring); void
>>>>>>> +amdgpu_sw_ring_ib_end(struct amdgpu_ring *ring);
>>>>>>> +
>>>>>>> +#endif
>>>>>
>>>
>


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