Inlined:
On 2022-10-18 05:08, jiadong.zhu@xxxxxxx wrote:
> From: "Jiadong.Zhu" <Jiadong.Zhu@xxxxxxx>
>
> The software ring is created to support priority context while there is only
> one hardware queue for gfx.
>
> Every software ring has its fence driver and could be used as an ordinary ring
> for the GPU scheduler.
> Multiple software rings are bound 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.
> v4: Remove amdgpu_ring_sw_init/fini functions,
> using gtt for sw ring buffer for later dma copy
> optimization.
> v5: Allocate ring entry dynamically in the muxer.
> v6: Update comments for the ring muxer.
> v7: Modify for function naming.
> v8: Combine software ring functions into amdgpu_ring_mux.c
>
> Cc: Christian Koenig <Christian.Koenig@xxxxxxx>
> Cc: Luben Tuikov <Luben.Tuikov@xxxxxxx>
> Cc: Andrey Grodzovsky <Andrey.Grodzovsky@xxxxxxx>
> Cc: Michel Dänzer <michel@xxxxxxxxxxx>
> Signed-off-by: Jiadong.Zhu <Jiadong.Zhu@xxxxxxx>
> Acked-by: Huang Rui <ray.huang@xxxxxxx>
> ---
> drivers/gpu/drm/amd/amdgpu/Makefile | 3 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h | 3 +
> drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 4 +
> drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c | 217 +++++++++++++++++++
> drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.h | 76 +++++++
> 5 files changed, 302 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
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile b/drivers/gpu/drm/amd/amdgpu/Makefile
> index 3e0e2eb7e235..add7da53950c 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_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..9996dadb39f7 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..40b1277b4f0c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> @@ -278,6 +278,10 @@ struct amdgpu_ring {
> bool is_mes_queue;
> uint32_t hw_queue_id;
> struct amdgpu_mes_ctx_data *mes_ctx;
> +
> + bool is_sw_ring;
> + unsigned int entry_index;
> +
> };
>
> #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..43cab8a37754
> --- /dev/null
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c
> @@ -0,0 +1,217 @@
> +/*
> + * 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/slab.h>
> +#include <drm/drm_print.h>
> +
> +#include "amdgpu_ring_mux.h"
> +#include "amdgpu_ring.h"
> +#include "amdgpu.h"
> +
> +#define AMDGPU_MUX_RESUBMIT_JIFFIES_TIMEOUT (HZ / 2)
> +
> +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;
> + spin_lock_init(&mux->lock);
> +
> + return 0;
> +}
> +
> +void amdgpu_ring_mux_fini(struct amdgpu_ring_mux *mux)
> +{
> + kfree(mux->ring_entry);
> + mux->ring_entry = NULL;
> + mux->num_ring_entries = 0;
> + mux->ring_entry_size = 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 >= mux->ring_entry_size) {
> + DRM_ERROR("add sw ring exceeding max entry size\n");
> + return -ENOENT;
> + }
> +
> + e = &mux->ring_entry[mux->num_ring_entries];
> + ring->entry_index = mux->num_ring_entries;
> + e->ring = ring;
> +
> + mux->num_ring_entries += 1;
Why is this all the way down here right next to the "return 0;"?
Move it up, so that it is clearly visible and in context,
right after "ring->entry_index = mux->num_ring_entries;".
IOW, the "adding" of an entry should be clearly visible and in context.
So it should look something like this:
...
e = &mux->ring_entry[mux->num_ring_entries];
ring->entry_index = mux->num_ring_entries;
mux->num_ring_entries += 1;
e->ring = ring;
return 0;
}
With that changed, this patch is Acked-by: Luben Tuikov <luben.tuikov@xxxxxxx>.
Regards.
Luben
> + return 0;
> +}
> +
> +static inline struct amdgpu_mux_entry *amdgpu_ring_mux_sw_entry(struct amdgpu_ring_mux *mux,
> + struct amdgpu_ring *ring)
> +{
> + return ring->entry_index < mux->ring_entry_size ?
> + &mux->ring_entry[ring->entry_index] : NULL;
> +}
> +
> +/* copy packages on sw ring range[begin, end) */
> +static void amdgpu_ring_mux_copy_pkt_from_sw_ring(struct amdgpu_ring_mux *mux,
> + struct amdgpu_ring *ring,
> + u64 s_start, u64 s_end)
> +{
> + u64 start, end;
> + struct amdgpu_ring *real_ring = mux->real_ring;
> +
> + start = s_start & ring->buf_mask;
> + end = s_end & ring->buf_mask;
> +
> + if (start == end) {
> + DRM_ERROR("no more data copied from sw ring\n");
> + return;
> + }
> + if (start > end) {
> + amdgpu_ring_alloc(real_ring, (ring->ring_size >> 2) + end - start);
> + amdgpu_ring_write_multiple(real_ring, (void *)&ring->ring[start],
> + (ring->ring_size >> 2) - start);
> + amdgpu_ring_write_multiple(real_ring, (void *)&ring->ring[0], end);
> + } else {
> + amdgpu_ring_alloc(real_ring, end - start);
> + amdgpu_ring_write_multiple(real_ring, (void *)&ring->ring[start], end - start);
> + }
> +}
> +
> +void amdgpu_ring_mux_set_wptr(struct amdgpu_ring_mux *mux, struct amdgpu_ring *ring, u64 wptr)
> +{
> + struct amdgpu_mux_entry *e;
> +
> + e = amdgpu_ring_mux_sw_entry(mux, ring);
> + if (!e) {
> + DRM_ERROR("cannot find entry for sw ring\n");
> + return;
> + }
> +
> + spin_lock(&mux->lock);
> + e->sw_cptr = e->sw_wptr;
> + e->sw_wptr = wptr;
> + e->start_ptr_in_hw_ring = mux->real_ring->wptr;
> +
> + amdgpu_ring_mux_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);
> +
> + spin_unlock(&mux->lock);
> +}
> +
> +u64 amdgpu_ring_mux_get_wptr(struct amdgpu_ring_mux *mux, struct amdgpu_ring *ring)
> +{
> + struct amdgpu_mux_entry *e;
> +
> + e = amdgpu_ring_mux_sw_entry(mux, ring);
> + if (!e) {
> + DRM_ERROR("cannot find entry for sw ring\n");
> + return 0;
> + }
> +
> + return e->sw_wptr;
> +}
> +
> +/*
> + * The return value of the readptr is not precise while the other rings could
> + * write data onto the real ring buffer.After overwriting on the real ring, we
> + * can not decide if our packages have been excuted or not read yet. However,
> + * this function is only called by the tools such as umr to collect the latest
> + * packages for the hang analysis. We assume the hang happens near our latest
> + * submit. Thus we could use the following logic to give the clue:
> + * If the readptr is between start and end, then we return the copy pointer
> + * plus the distance from start to readptr. If the readptr is before start, we
> + * return the copy pointer. Lastly, if the readptr is past end, we return the
> + * write pointer.
> + */
> +u64 amdgpu_ring_mux_get_rptr(struct amdgpu_ring_mux *mux, struct amdgpu_ring *ring)
> +{
> + struct amdgpu_mux_entry *e;
> + u64 readp, offset, start, end;
> +
> + e = amdgpu_ring_mux_sw_entry(mux, ring);
> + if (!e) {
> + DRM_ERROR("no sw entry found!\n");
> + return 0;
> + }
> +
> + readp = amdgpu_ring_get_rptr(mux->real_ring);
> +
> + 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) {
> + if (readp <= end)
> + readp += mux->real_ring->ring_size >> 2;
> + end += mux->real_ring->ring_size >> 2;
> + }
> +
> + if (start <= readp && readp <= end) {
> + offset = readp - start;
> + e->sw_rptr = (e->sw_cptr + offset) & ring->buf_mask;
> + } else if (readp < start) {
> + e->sw_rptr = e->sw_cptr;
> + } else {
> + /* end < readptr */
> + e->sw_rptr = e->sw_wptr;
> + }
> +
> + return e->sw_rptr;
> +}
> +
> +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;
> +
> + WARN_ON(!ring->is_sw_ring);
> + return amdgpu_ring_mux_get_rptr(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;
> +
> + WARN_ON(!ring->is_sw_ring);
> + return amdgpu_ring_mux_get_wptr(mux, ring);
> +}
> +
> +void amdgpu_sw_ring_set_wptr_gfx(struct amdgpu_ring *ring)
> +{
> + struct amdgpu_device *adev = ring->adev;
> + struct amdgpu_ring_mux *mux = &adev->gfx.muxer;
> +
> + WARN_ON(!ring->is_sw_ring);
> + amdgpu_ring_mux_set_wptr(mux, ring, ring->wptr);
> +}
> +
> +/* Override insert_nop to prevent emitting nops to the software rings */
> +void amdgpu_sw_ring_insert_nop(struct amdgpu_ring *ring, uint32_t count)
> +{
> + WARN_ON(!ring->is_sw_ring);
> +}
> 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..d91629589577
> --- /dev/null
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.h
> @@ -0,0 +1,76 @@
> +/*
> + * 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;
> +/**
> + * struct amdgpu_mux_entry - the entry recording software rings copying information.
> + * @ring: the pointer to the software ring.
> + * @start_ptr_in_hw_ring: last start location copied to in the hardware ring.
> + * @end_ptr_in_hw_ring: last end location copied to in the hardware 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.
> + */
> +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_entry;
> + unsigned int num_ring_entries;
> + unsigned int ring_entry_size;
> + /*the lock for copy data from different software rings*/
> + spinlock_t lock;
> +};
> +
> +int amdgpu_ring_mux_init(struct amdgpu_ring_mux *mux, struct amdgpu_ring *ring,
> + unsigned int entry_size);
> +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_mux_set_wptr(struct amdgpu_ring_mux *mux, struct amdgpu_ring *ring, u64 wptr);
> +u64 amdgpu_ring_mux_get_wptr(struct amdgpu_ring_mux *mux, struct amdgpu_ring *ring);
> +u64 amdgpu_ring_mux_get_rptr(struct amdgpu_ring_mux *mux, 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_insert_nop(struct amdgpu_ring *ring, uint32_t count);
> +void amdgpu_sw_ring_ib_begin(struct amdgpu_ring *ring);
> +void amdgpu_sw_ring_ib_end(struct amdgpu_ring *ring);
> +
> +#endif
