[AMD Official Use Only - General]
>> + return need_preempt && !mux->s_resubmit;
>> Well what exactly are you trying to do here? Finding if a lower priority ring has unsignaled fences?
> Yes, we are peeking the fence_drv data at the time high priority ibs are going to emit. The result is not necessarily accurate because we would check the fence after preemption complete.
>Please use amdgpu_fence_count_emitted() for this instead.
amdgpu_fence_count_emitted calls amdgpu_fence_process in it. We are in high priority ring schedule task while calling amdgpu_mcbp_scan, amdgpu_fence_process on both rings might lower the performance.
Maybe we could add a function in amdgpu_fence.c to count_emmited without amdgpu_fence_process?
>Also what is the check of s_resubmit state good for here?
The resubmission happens on the low priority ring shed task. Thinking of the situation that two high prio ib requests from high priority calling amdgpu_mcbp_scan, we don’t want to trigger preemption twice when low priority ring has not resubmitted packages.
Thanks,
Jiadong
-----Original Message-----
From: Koenig, Christian <Christian.Koenig@xxxxxxx>
Sent: Friday, September 23, 2022 6:13 PM
To: Zhu, Jiadong <Jiadong.Zhu@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
Cc: Tuikov, Luben <Luben.Tuikov@xxxxxxx>; Grodzovsky, Andrey <Andrey.Grodzovsky@xxxxxxx>
Subject: Re: [PATCH 4/5] drm/amdgpu: Implement OS triggered MCBP (v5)
Am 23.09.22 um 11:24 schrieb Zhu, Jiadong:
> [AMD Official Use Only - General]
>
> Inlined.
>
> Thanks,
> Jiadong
>
> -----Original Message-----
> From: Koenig, Christian <Christian.Koenig@xxxxxxx>
> Sent: Wednesday, September 21, 2022 9:01 PM
> To: Zhu, Jiadong <Jiadong.Zhu@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: Tuikov, Luben <Luben.Tuikov@xxxxxxx>; Grodzovsky, Andrey
> <Andrey.Grodzovsky@xxxxxxx>
> Subject: Re: [PATCH 4/5] drm/amdgpu: Implement OS triggered MCBP (v5)
>
> Am 21.09.22 um 11:41 schrieb jiadong.zhu@xxxxxxx:
>> From: "Jiadong.Zhu" <Jiadong.Zhu@xxxxxxx>
>>
>> Trigger Mid-Command Buffer Preemption according to the priority of
>> the software rings and the hw fence signalling condition.
>>
>> The muxer saves the locations of the indirect buffer frames from the
>> software ring together with the fence sequence number in its fifo
>> queue, and pops out those records when the fences are signalled. The
>> locations are used to resubmit packages in preemption scenarios by coping the chunks from the software ring.
> Maybe change the subject a bit. The MCBP is not really triggered by the core Linux kernel.
>
> Maybe write instead "MCBP based on DRM scheduler".
>
>> v2: Update comment style.
>> v3: Fix conflict caused by previous modifications.
>> v4: Remove unnecessary prints.
>> v5: Fix corner cases for resubmission cases.
>>
>> Cc: Christian Koenig <Christian.Koenig@xxxxxxx>
>> Cc: Luben Tuikov <Luben.Tuikov@xxxxxxx>
>> Cc: Andrey Grodzovsky <Andrey.Grodzovsky@xxxxxxx>
>> Acked-by: Luben Tuikov <luben.tuikov@xxxxxxx>
>> Signed-off-by: Jiadong.Zhu <Jiadong.Zhu@xxxxxxx>
>> ---
>> drivers/gpu/drm/amd/amdgpu/Makefile | 2 +-
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c | 2 +
>> drivers/gpu/drm/amd/amdgpu/amdgpu_mcbp.c | 91 +++++++++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_mcbp.h | 29 +++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 12 ++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 3 +
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c | 186 ++++++++++++++++++-
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.h | 24 +++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.c | 27 +++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 2 +
>> 10 files changed, 372 insertions(+), 6 deletions(-)
>> create mode 100644 drivers/gpu/drm/amd/amdgpu/amdgpu_mcbp.c
>> create mode 100644 drivers/gpu/drm/amd/amdgpu/amdgpu_mcbp.h
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile
>> b/drivers/gpu/drm/amd/amdgpu/Makefile
>> index 85224bc81ce5..24c5aa19bbf2 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/Makefile
>> +++ b/drivers/gpu/drm/amd/amdgpu/Makefile
>> @@ -59,7 +59,7 @@ amdgpu-y += amdgpu_device.o amdgpu_kms.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_sw_ring.o amdgpu_ring_mux.o
>> + amdgpu_sw_ring.o amdgpu_ring_mux.o amdgpu_mcbp.o
> This functionality is spread over to many files. Probably better to move this into the amdgpu_ring_mux.c as well.
>
>> amdgpu-$(CONFIG_PROC_FS) += amdgpu_fdinfo.o
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
>> index 258cffe3c06a..af86d87e2f3b 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
>> @@ -211,6 +211,7 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned num_ibs,
>> }
>> }
>>
>> + amdgpu_ring_ib_begin(ring);
>> if (job && ring->funcs->init_cond_exec)
>> patch_offset = amdgpu_ring_init_cond_exec(ring);
>>
>> @@ -285,6 +286,7 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned num_ibs,
>> ring->hw_prio == AMDGPU_GFX_PIPE_PRIO_HIGH)
>> ring->funcs->emit_wave_limit(ring, false);
>>
>> + amdgpu_ring_ib_end(ring);
>> amdgpu_ring_commit(ring);
>> return 0;
>> }
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mcbp.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_mcbp.c
>> new file mode 100644
>> index 000000000000..121b1a4e0f04
>> --- /dev/null
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mcbp.c
>> @@ -0,0 +1,91 @@
>> +/*
>> + * 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 <linux/delay.h>
>> +#include <linux/kernel.h>
>> +#include <linux/firmware.h>
>> +#include <linux/module.h>
>> +#include <linux/pci.h>
>> +#include <drm/gpu_scheduler.h>
>> +
>> +#include "amdgpu.h"
>> +#include "amdgpu_mcbp.h"
>> +#include "amdgpu_ring.h"
>> +
>> +/* Trigger Mid-Command Buffer Preemption (MCBP) and find if we need
>> +to resubmit. */ int amdgpu_mcbp_trigger_preempt(struct
>> +amdgpu_ring_mux *mux) {
>> + struct amdgpu_mux_entry *e;
>> + struct amdgpu_ring *ring = NULL;
>> + int i;
>> +
>> + spin_lock(&mux->lock);
>> +
>> + amdgpu_ring_preempt_ib(mux->real_ring);
>> +
>> + for (i = 0; i < mux->num_ring_entries; i++) {
>> + e = &mux->ring_entry[i];
>> + if (e->ring->hw_prio <= AMDGPU_RING_PRIO_DEFAULT) {
>> + ring = e->ring;
>> + break;
>> + }
>> + }
>> +
>> + if (!ring) {
>> + DRM_ERROR("cannot find low priority ring\n");
>> + spin_unlock(&mux->lock);
>> + return -ENOENT;
>> + }
>> +
>> + amdgpu_fence_process(ring);
>> That's usually and extremely bad idea since fence processing should only be kicked of from the interrupt handler.
>> Otherwise you have interrupt handler and this thread here racing to signaling fences.
> We have to block low priority ibs copied to the real ring and check the seq no signaled here.
> I will refactor to use the trailing fence irq to handle this.
>
>> +
>> + if (atomic_read(&ring->fence_drv.last_seq) !=
>> + ring->fence_drv.sync_seq) {
>> + mux->s_resubmit = true;
>> + mux->seq_no_resubmit = ring->fence_drv.sync_seq;
>> Don't touch any fence handling internals here. If you need to know
>> which fences are signaled and which aren't look into amdgpu_fence.c
> I would use amdgpu_fence_count_emitted in irq hander to meet this.
>
>
>> + amdgpu_ring_mux_schedule_resubmit(mux);
>> + }
>> +
>> + spin_unlock(&mux->lock);
>> + return 0;
>> +}
>> +
>> +/*scan on low prio rings to have unsignaled fence and high ring has
>> +no fence.*/
> What exactly should that comment mean?
>
>> +int amdgpu_mcbp_scan(struct amdgpu_ring_mux *mux) {
>> + struct amdgpu_ring *ring;
>> + uint32_t seq, last_seq;
>> + int i, need_preempt;
>> +
>> + need_preempt = 0;
>> + for (i = 0; i < mux->num_ring_entries; i++) {
>> + ring = mux->ring_entry[i].ring;
>> + last_seq = atomic_read(&ring->fence_drv.last_seq);
>> + seq = READ_ONCE(ring->fence_drv.sync_seq);
>> + if (ring->hw_prio > AMDGPU_RING_PRIO_DEFAULT && last_seq < seq)
>> + return 0;
>> + if (ring->hw_prio <= AMDGPU_RING_PRIO_DEFAULT && last_seq < seq)
>> + need_preempt = 1;
>> + }
>> + return need_preempt && !mux->s_resubmit;
>> Well what exactly are you trying to do here? Finding if a lower priority ring has unsignaled fences?
> Yes, we are peeking the fence_drv data at the time high priority ibs are going to emit. The result is not necessarily accurate because we would check the fence after preemption complete.
Please use amdgpu_fence_count_emitted() for this instead.
Also what is the check of s_resubmit state good for here?
Regards,
Christian.
>
> Regards,
> Christian.
>
>> +}
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mcbp.h
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_mcbp.h
>> new file mode 100644
>> index 000000000000..0033bcba8d03
>> --- /dev/null
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mcbp.h
>> @@ -0,0 +1,29 @@
>> +/*
>> + * 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_MCBP_H__
>> +#define __AMDGPU_MCBP_H__
>> +
>> +int amdgpu_mcbp_trigger_preempt(struct amdgpu_ring_mux *mux); int
>> +amdgpu_mcbp_scan(struct amdgpu_ring_mux *mux); #endif
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
>> index 4eaf3bd332f7..94362c39b73e 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
>> @@ -574,3 +574,15 @@ int amdgpu_ring_init_mqd(struct amdgpu_ring
>> *ring)
>>
>> return mqd_mgr->init_mqd(adev, ring->mqd_ptr, &prop);
>> }
>> +
>> +void amdgpu_ring_ib_begin(struct amdgpu_ring *ring) {
>> + if (ring->is_sw_ring)
>> + amdgpu_sw_ring_ib_begin(ring); }
>> +
>> +void amdgpu_ring_ib_end(struct amdgpu_ring *ring) {
>> + if (ring->is_sw_ring)
>> + amdgpu_sw_ring_ib_end(ring); }
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
>> index aeb48cc3666c..36726c28a806 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
>> @@ -312,6 +312,9 @@ struct amdgpu_ring {
>> #define amdgpu_ring_preempt_ib(r) (r)->funcs->preempt_ib(r)
>>
>> int amdgpu_ring_alloc(struct amdgpu_ring *ring, unsigned ndw);
>> +void amdgpu_ring_ib_begin(struct amdgpu_ring *ring); void
>> +amdgpu_ring_ib_end(struct amdgpu_ring *ring);
>> +
>> void amdgpu_ring_insert_nop(struct amdgpu_ring *ring, uint32_t count);
>> void amdgpu_ring_generic_pad_ib(struct amdgpu_ring *ring, struct amdgpu_ib *ib);
>> void amdgpu_ring_commit(struct amdgpu_ring *ring); diff --git
>> a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c
>> index d6b30db27104..70dd725432d4 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c
>> @@ -24,30 +24,59 @@
>> #include <drm/drm_print.h>
>>
>> #include "amdgpu_ring_mux.h"
>> +#include "amdgpu_mcbp.h"
>> #include "amdgpu_ring.h"
>>
>> #define AMDGPU_MUX_RESUBMIT_JIFFIES_TIMEOUT (HZ / 2)
>>
>> +static struct kmem_cache *amdgpu_mux_chunk_slab;
>> +
>> static void copy_pkt_from_sw_ring(struct amdgpu_ring_mux *mux, struct amdgpu_ring *ring,
>> u64 s_start, u64 s_end);
>> +static void amdgpu_mux_resubmit_chunks(struct amdgpu_ring_mux *mux,
>> +bool is_fallback); static void amdgpu_mux_resubmit_fallback(struct
>> +timer_list *t);
>>
>> int amdgpu_ring_mux_init(struct amdgpu_ring_mux *mux, struct amdgpu_ring *ring,
>> unsigned int entry_size)
>> {
>> mux->real_ring = ring;
>> mux->num_ring_entries = 0;
>> +
>> mux->ring_entry = kcalloc(entry_size, sizeof(struct amdgpu_mux_entry), GFP_KERNEL);
>> if (!mux->ring_entry)
>> return -ENOMEM;
>>
>> mux->ring_entry_size = entry_size;
>> + mux->s_resubmit = false;
>> +
>> + amdgpu_mux_chunk_slab = kmem_cache_create("amdgpu_mux_chunk",
>> + sizeof(struct amdgpu_mux_chunk), 0,
>> + SLAB_HWCACHE_ALIGN, NULL);
>> + if (!amdgpu_mux_chunk_slab) {
>> + DRM_ERROR("create amdgpu_mux_chunk cache failed\n");
>> + return -ENOMEM;
>> + }
>> +
>> spin_lock_init(&mux->lock);
>> + timer_setup(&mux->resubmit_timer, amdgpu_mux_resubmit_fallback,
>> + 0);
>>
>> return 0;
>> }
>>
>> void amdgpu_ring_mux_fini(struct amdgpu_ring_mux *mux)
>> {
>> + struct amdgpu_mux_entry *e;
>> + struct amdgpu_mux_chunk *chunk, *chunk2;
>> + int i;
>> +
>> + for (i = 0; i < mux->num_ring_entries; i++) {
>> + e = &mux->ring_entry[i];
>> + list_for_each_entry_safe(chunk, chunk2, &e->list, entry) {
>> + list_del(&chunk->entry);
>> + kmem_cache_free(amdgpu_mux_chunk_slab, chunk);
>> + }
>> + }
>> + kmem_cache_destroy(amdgpu_mux_chunk_slab);
>> kfree(mux->ring_entry);
>> mux->ring_entry = NULL;
>> mux->num_ring_entries = 0;
>> @@ -67,6 +96,7 @@ int amdgpu_ring_mux_add_sw_ring(struct amdgpu_ring_mux *mux, struct amdgpu_ring
>> ring->entry_index = mux->num_ring_entries;
>> e->ring = ring;
>>
>> + INIT_LIST_HEAD(&e->list);
>> mux->num_ring_entries += 1;
>> return 0;
>> }
>> @@ -82,6 +112,9 @@ void amdgpu_ring_set_wptr_to_mux(struct amdgpu_ring_mux *mux, struct amdgpu_ring
>> {
>> struct amdgpu_mux_entry *e;
>>
>> + if (ring->hw_prio <= AMDGPU_RING_PRIO_DEFAULT)
>> + amdgpu_mux_resubmit_chunks(mux, false);
>> +
>> e = amdgpu_get_sw_entry(mux, ring);
>> if (!e) {
>> DRM_ERROR("cannot find entry for sw ring\n"); @@
>> -90,13 +123,19 @@ void amdgpu_ring_set_wptr_to_mux(struct
>> amdgpu_ring_mux *mux, struct amdgpu_ring
>>
>> spin_lock(&mux->lock);
>> e->sw_cptr = e->sw_wptr;
>> + if (ring->hw_prio <= AMDGPU_RING_PRIO_DEFAULT && e->sw_cptr < mux->wptr_resubmit)
>> + e->sw_cptr = mux->wptr_resubmit;
>> e->sw_wptr = wptr;
>> e->start_ptr_in_hw_ring = mux->real_ring->wptr;
>>
>> - copy_pkt_from_sw_ring(mux, ring, e->sw_cptr, wptr);
>> - e->end_ptr_in_hw_ring = mux->real_ring->wptr;
>> - amdgpu_ring_commit(mux->real_ring);
>> -
>> + /* donnot copy the ibs which have been resubmitted*/
>> + if (ring->hw_prio > AMDGPU_RING_PRIO_DEFAULT || mux->wptr_resubmit < wptr) {
>> + copy_pkt_from_sw_ring(mux, ring, e->sw_cptr, wptr);
>> + e->end_ptr_in_hw_ring = mux->real_ring->wptr;
>> + amdgpu_ring_commit(mux->real_ring);
>> + } else {
>> + e->end_ptr_in_hw_ring = mux->real_ring->wptr;
>> + }
>> spin_unlock(&mux->lock);
>> }
>>
>> @@ -159,7 +198,7 @@ u64 amdgpu_ring_get_rptr_from_mux(struct amdgpu_ring_mux *mux, struct amdgpu_rin
>> return e->sw_rptr;
>> }
>>
>> -/* copy packages on sw ring range[begin, end) */
>> +/* copy packages on sw ring range[start, end) */
>> static void copy_pkt_from_sw_ring(struct amdgpu_ring_mux *mux, struct amdgpu_ring *ring,
>> u64 s_start, u64 s_end)
>> {
>> @@ -183,3 +222,140 @@ static void copy_pkt_from_sw_ring(struct amdgpu_ring_mux *mux, struct amdgpu_rin
>> amdgpu_ring_write_multiple(real_ring, (void *)&ring->ring[start], end - start);
>> }
>> }
>> +
>> +void amdgpu_ring_mux_schedule_resubmit(struct amdgpu_ring_mux *mux) {
>> + mod_timer(&mux->resubmit_timer, jiffies +
>> +AMDGPU_MUX_RESUBMIT_JIFFIES_TIMEOUT);
>> +}
>> +
>> +void amdgpu_ring_mux_start_ib(struct amdgpu_ring_mux *mux, struct
>> +amdgpu_ring *ring) {
>> + struct amdgpu_mux_entry *e;
>> + struct amdgpu_mux_chunk *chunk;
>> +
>> + amdgpu_mux_resubmit_chunks(mux, false);
>> +
>> + e = amdgpu_get_sw_entry(mux, ring);
>> + if (!e) {
>> + DRM_ERROR("cannot find entry!\n");
>> + return;
>> + }
>> +
>> + chunk = kmem_cache_alloc(amdgpu_mux_chunk_slab, GFP_KERNEL);
>> + if (!chunk) {
>> + DRM_ERROR("alloc amdgpu_mux_chunk_slab failed\n");
>> + return;
>> + }
>> +
>> + chunk->start = ring->wptr;
>> + list_add_tail(&chunk->entry, &e->list); }
>> +
>> +static void scan_and_remove_signaled_chunk(struct amdgpu_ring_mux
>> +*mux, struct amdgpu_ring *ring) {
>> + uint32_t last_seq, size = 0;
>> + struct amdgpu_mux_entry *e;
>> + struct amdgpu_mux_chunk *chunk, *tmp;
>> +
>> + e = amdgpu_get_sw_entry(mux, ring);
>> + if (!e) {
>> + DRM_ERROR("cannot find entry!\n");
>> + return;
>> + }
>> +
>> + last_seq = atomic_read(&ring->fence_drv.last_seq);
>> +
>> + list_for_each_entry_safe(chunk, tmp, &e->list, entry) {
>> + if (chunk->sync_seq <= last_seq) {
>> + list_del(&chunk->entry);
>> + kmem_cache_free(amdgpu_mux_chunk_slab, chunk);
>> + } else {
>> + size++;
>> + }
>> + }
>> +}
>> +
>> +void amdgpu_ring_mux_end_ib(struct amdgpu_ring_mux *mux, struct
>> +amdgpu_ring *ring) {
>> + struct amdgpu_mux_entry *e;
>> + struct amdgpu_mux_chunk *chunk;
>> +
>> + e = amdgpu_get_sw_entry(mux, ring);
>> + if (!e) {
>> + DRM_ERROR("cannot find entry!\n");
>> + return;
>> + }
>> +
>> + chunk = list_last_entry(&e->list, struct amdgpu_mux_chunk, entry);
>> + if (!chunk) {
>> + DRM_ERROR("cannot find chunk!\n");
>> + return;
>> + }
>> +
>> + chunk->end = ring->wptr;
>> + chunk->sync_seq = READ_ONCE(ring->fence_drv.sync_seq);
>> +
>> + scan_and_remove_signaled_chunk(mux, ring); }
>> +
>> +static void amdgpu_mux_resubmit_chunks(struct amdgpu_ring_mux *mux,
>> +bool is_fallback) {
>> + struct amdgpu_mux_entry *e = NULL;
>> + struct amdgpu_mux_chunk *chunk;
>> + uint32_t seq, last_seq;
>> + int i;
>> +
>> + if (is_fallback) {
>> + if (!spin_trylock(&mux->lock)) {
>> + amdgpu_ring_mux_schedule_resubmit(mux);
>> + DRM_ERROR("reschedule resubmit\n");
>> + return;
>> + }
>> + } else {
>> + spin_lock(&mux->lock);
>> + }
>> +
>> + /*find low priority entries:*/
>> + if (!mux->s_resubmit) {
>> + spin_unlock(&mux->lock);
>> + return;
>> + }
>> +
>> + for (i = 0; i < mux->num_ring_entries; i++) {
>> + if (mux->ring_entry[i].ring->hw_prio <= AMDGPU_RING_PRIO_DEFAULT) {
>> + e = &mux->ring_entry[i];
>> + break;
>> + }
>> + }
>> +
>> + if (!e) {
>> + DRM_ERROR("%s no low priority ring found\n", __func__);
>> + spin_unlock(&mux->lock);
>> + return;
>> + }
>> +
>> + last_seq = atomic_read(&e->ring->fence_drv.last_seq);
>> + seq = mux->seq_no_resubmit;
>> + if (last_seq < seq) {
>> + /*resubmit all the fences between (last_seq, seq]*/
>> + list_for_each_entry(chunk, &e->list, entry) {
>> + if (chunk->sync_seq > last_seq && chunk->sync_seq <= seq) {
>> + copy_pkt_from_sw_ring(mux, e->ring, chunk->start, chunk->end);
>> + mux->wptr_resubmit = chunk->end;
>> + amdgpu_ring_commit(mux->real_ring);
>> + }
>> + }
>> + }
>> +
>> + del_timer(&mux->resubmit_timer);
>> + mux->s_resubmit = false;
>> + spin_unlock(&mux->lock);
>> +}
>> +
>> +static void amdgpu_mux_resubmit_fallback(struct timer_list *t) {
>> + struct amdgpu_ring_mux *mux = from_timer(mux, t,
>> +resubmit_timer);
>> +
>> + DRM_INFO("calling %s\n", __func__);
>> + amdgpu_mux_resubmit_chunks(mux, true); }
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.h
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.h
>> index e8ee34e6b9a5..f6fc0afa3cc7 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.h
>> @@ -35,6 +35,7 @@ struct amdgpu_ring;
>> * sw_cptr -- the position of the copy pointer in the sw ring
>> * sw_rptr -- the read pointer in software ring
>> * sw_wptr -- the write pointer in software ring
>> + * list -- list head for amdgpu_mux_chunk
>> */
>> struct amdgpu_mux_entry {
>> struct amdgpu_ring *ring;
>> @@ -43,6 +44,7 @@ struct amdgpu_mux_entry {
>> u64 sw_cptr;
>> u64 sw_rptr;
>> u64 sw_wptr;
>> + struct list_head list;
>> };
>>
>> struct amdgpu_ring_mux {
>> @@ -53,6 +55,24 @@ struct amdgpu_ring_mux {
>> unsigned int ring_entry_size;
>> /*the lock for copy data from different software rings*/
>> spinlock_t lock;
>> + bool s_resubmit;
>> + uint32_t seq_no_resubmit;
>> + u64 wptr_resubmit;
>> + struct timer_list resubmit_timer;
>> +};
>> +
>> +/*
>> + * amdgpu_munx_chunk -- save the location of indirect buffer's
>> +package on softare rings
>> + * entry -- the list entry.
>> + * sync_seq -- the fence seqno related with the saved IB.
>> + * start -- start location on the software ring.
>> + * end -- end location on the software ring.
>> + */
>> +struct amdgpu_mux_chunk {
>> + struct list_head entry;
>> + uint32_t sync_seq;
>> + u64 start;
>> + u64 end;
>> };
>>
>> int amdgpu_ring_mux_init(struct amdgpu_ring_mux *mux, struct
>> amdgpu_ring *ring, @@ -63,4 +83,8 @@ void amdgpu_ring_set_wptr_to_mux(struct amdgpu_ring_mux *mux, struct amdgpu_ring
>> 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);
>>
>> +void amdgpu_ring_mux_start_ib(struct amdgpu_ring_mux *mux, struct
>> +amdgpu_ring *ring); void amdgpu_ring_mux_end_ib(struct
>> +amdgpu_ring_mux *mux, struct amdgpu_ring *ring); void
>> +amdgpu_ring_mux_schedule_resubmit(struct amdgpu_ring_mux *mux);
>> +
>> #endif
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.c
>> index ec50793aa54d..4809ecf76180 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sw_ring.c
>> @@ -26,6 +26,7 @@
>>
>> #include "amdgpu_sw_ring.h"
>> #include "amdgpu_ring_mux.h"
>> +#include "amdgpu_mcbp.h"
>>
>> u64 amdgpu_sw_ring_get_rptr_gfx(struct amdgpu_ring *ring)
>> {
>> @@ -58,3 +59,29 @@ void amdgpu_sw_ring_commit(struct amdgpu_ring *ring)
>> WARN_ON(!ring->is_sw_ring);
>> amdgpu_ring_set_wptr_to_mux(mux, ring, ring->wptr);
>> }
>> +
>> +void amdgpu_sw_ring_ib_begin(struct amdgpu_ring *ring) {
>> + struct amdgpu_device *adev = ring->adev;
>> + struct amdgpu_ring_mux *mux = &adev->gfx.muxer;
>> +
>> + WARN_ON(!ring->is_sw_ring);
>> + if (ring->hw_prio > AMDGPU_RING_PRIO_DEFAULT) {
>> + if (amdgpu_mcbp_scan(mux) > 0)
>> + amdgpu_mcbp_trigger_preempt(mux);
>> + return;
>> + }
>> +
>> + amdgpu_ring_mux_start_ib(mux, ring); }
>> +
>> +void amdgpu_sw_ring_ib_end(struct amdgpu_ring *ring) {
>> + struct amdgpu_device *adev = ring->adev;
>> + struct amdgpu_ring_mux *mux = &adev->gfx.muxer;
>> +
>> + WARN_ON(!ring->is_sw_ring);
>> + if (ring->hw_prio > AMDGPU_RING_PRIO_DEFAULT)
>> + return;
>> + amdgpu_ring_mux_end_ib(mux, ring); }
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> index 9596c22fded6..b7e94553f4fb 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> @@ -601,6 +601,7 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
>> if (!vm_flush_needed && !gds_switch_needed && !need_pipe_sync)
>> return 0;
>>
>> + amdgpu_ring_ib_begin(ring);
>> if (ring->funcs->init_cond_exec)
>> patch_offset = amdgpu_ring_init_cond_exec(ring);
>>
>> @@ -661,6 +662,7 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
>> amdgpu_ring_emit_switch_buffer(ring);
>> amdgpu_ring_emit_switch_buffer(ring);
>> }
>> + amdgpu_ring_ib_end(ring);
>> return 0;
>> }
>>
