[PATCH] drm/amdgpu: fix a kcq hang issue for SRIOV
Alex Deucher
alexdeucher at gmail.com
Tue Mar 27 15:15:48 UTC 2018
On Tue, Mar 27, 2018 at 1:58 AM, Emily Deng <Emily.Deng at amd.com> wrote:
> issue:
> the vmflush in KCQ could be preempted (not like GFX ring
> which doesn't allow preemption in ring buffer) and this lead
> to vm flush fail when there is a world switch during
> the vm flush procedure (between write invalidate request
> and query invalidate ack)
>
> fix:
> separate vm flush for gfx and compute ring, and use
> the new format command in compute's vm flush which
> use only one package so no preemption could allowed
>
> Signed-off-by: Monk Liu <Monk.Liu at amd.com>
> Signed-off-by: Emily Deng <Emily.Deng at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 +
> drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 2 ++
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 10 +++++++++-
> drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c | 18 +++++++++++++-----
> 4 files changed, 25 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index a7e2229..986659f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -1790,6 +1790,7 @@ amdgpu_get_sdma_instance(struct amdgpu_ring *ring)
> #define amdgpu_ring_emit_rreg(r, d) (r)->funcs->emit_rreg((r), (d))
> #define amdgpu_ring_emit_wreg(r, d, v) (r)->funcs->emit_wreg((r), (d), (v))
> #define amdgpu_ring_emit_reg_wait(r, d, v, m) (r)->funcs->emit_reg_wait((r), (d), (v), (m))
> +#define amdgpu_ring_emit_reg_wait1(r, d0, d1, v, m) (r)->funcs->emit_reg_wait1((r), (d0), (d1), (v), (m))
> #define amdgpu_ring_emit_tmz(r, b) (r)->funcs->emit_tmz((r), (b))
> #define amdgpu_ring_pad_ib(r, ib) ((r)->funcs->pad_ib((r), (ib)))
> #define amdgpu_ring_init_cond_exec(r) (r)->funcs->init_cond_exec((r))
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> index 1d0d250..d85df5d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> @@ -152,6 +152,8 @@ struct amdgpu_ring_funcs {
> void (*emit_wreg)(struct amdgpu_ring *ring, uint32_t reg, uint32_t val);
> void (*emit_reg_wait)(struct amdgpu_ring *ring, uint32_t reg,
> uint32_t val, uint32_t mask);
> + void (*emit_reg_wait1)(struct amdgpu_ring *ring, uint32_t reg0,
> + uint32_t reg1, uint32_t val, uint32_t mask);
This is pretty ugly. We don't need a new callback for this
workaround. It will just confuse things for other IPs. Just call
gfx_v9_0_wait_reg_mem() directly if you need it in
gmc_v9_0_emit_flush_gpu_tlb().
Alex
> void (*emit_tmz)(struct amdgpu_ring *ring, bool start);
> /* priority functions */
> void (*set_priority) (struct amdgpu_ring *ring,
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> index 1ae3de1..509c9d2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> @@ -4078,6 +4078,13 @@ static void gfx_v9_0_ring_emit_reg_wait(struct amdgpu_ring *ring, uint32_t reg,
> gfx_v9_0_wait_reg_mem(ring, 0, 0, 0, reg, 0, val, mask, 0x20);
> }
>
> +static void gfx_v9_0_ring_emit_reg_wait_compute(struct amdgpu_ring *ring,
> + uint32_t reg0, uint32_t reg1,
> + uint32_t val, uint32_t mask)
> +{
> + gfx_v9_0_wait_reg_mem(ring, 0, 0, 1, reg0, reg1, val, mask, 0x20);
> +}
> +
> static void gfx_v9_0_set_gfx_eop_interrupt_state(struct amdgpu_device *adev,
> enum amdgpu_interrupt_state state)
> {
> @@ -4415,7 +4422,7 @@ static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_compute = {
> 7 + /* gfx_v9_0_ring_emit_hdp_flush */
> 5 + /* hdp invalidate */
> 7 + /* gfx_v9_0_ring_emit_pipeline_sync */
> - SOC15_FLUSH_GPU_TLB_NUM_WREG * 5 +
> + (SOC15_FLUSH_GPU_TLB_NUM_WREG - 1) * 5 +
> SOC15_FLUSH_GPU_TLB_NUM_REG_WAIT * 7 +
> 2 + /* gfx_v9_0_ring_emit_vm_flush */
> 8 + 8 + 8, /* gfx_v9_0_ring_emit_fence x3 for user fence, vm fence */
> @@ -4433,6 +4440,7 @@ static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_compute = {
> .set_priority = gfx_v9_0_ring_set_priority_compute,
> .emit_wreg = gfx_v9_0_ring_emit_wreg,
> .emit_reg_wait = gfx_v9_0_ring_emit_reg_wait,
> + .emit_reg_wait1 = gfx_v9_0_ring_emit_reg_wait_compute,
> };
>
> static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_kiq = {
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> index e687363..968447d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> @@ -385,11 +385,19 @@ static uint64_t gmc_v9_0_emit_flush_gpu_tlb(struct amdgpu_ring *ring,
> amdgpu_ring_emit_wreg(ring, hub->ctx0_ptb_addr_hi32 + (2 * vmid),
> upper_32_bits(pd_addr));
>
> - amdgpu_ring_emit_wreg(ring, hub->vm_inv_eng0_req + eng, req);
> -
> - /* wait for the invalidate to complete */
> - amdgpu_ring_emit_reg_wait(ring, hub->vm_inv_eng0_ack + eng,
> - 1 << vmid, 1 << vmid);
> + /* The world switch cannot be allowed to occur while
> + some invalidation controller code is waiting for an ack.
> + To workaround the hardware restriction, replace the original
> + two command with one command for compute ring */
> + if (ring->funcs->type == AMDGPU_RING_TYPE_COMPUTE && amdgpu_sriov_vf(adev)) {
> + amdgpu_ring_emit_reg_wait1(ring, hub->vm_inv_eng0_req + eng,
> + hub->vm_inv_eng0_ack + eng, req, 1 << vmid);
> + } else {
> + amdgpu_ring_emit_wreg(ring, hub->vm_inv_eng0_req + eng, req);
> + /* wait for the invalidate to complete */
> + amdgpu_ring_emit_reg_wait(ring, hub->vm_inv_eng0_ack + eng,
> + 1 << vmid, 1 << vmid);
> + }
>
> return pd_addr;
> }
> --
> 2.7.4
>
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