[PATCH] drm/amdgpu: invalidate mmhub semphore workaround in gmc9/gmc10
Zhu, Changfeng
Changfeng.Zhu at amd.com
Fri Nov 22 10:12:34 UTC 2019
Thanks, Ray
I 'll submit the patch and continue to see the gfxhub semaphore problem.
BR,
Changfeng.
-----Original Message-----
From: Huang, Ray <Ray.Huang at amd.com>
Sent: Friday, November 22, 2019 5:16 PM
To: Zhu, Changfeng <Changfeng.Zhu at amd.com>
Cc: Koenig, Christian <Christian.Koenig at amd.com>; Xiao, Jack <Jack.Xiao at amd.com>; Zhou1, Tao <Tao.Zhou1 at amd.com>; Huang, Shimmer <Xinmei.Huang at amd.com>; amd-gfx at lists.freedesktop.org
Subject: Re: [PATCH] drm/amdgpu: invalidate mmhub semphore workaround in gmc9/gmc10
[AMD Official Use Only - Internal Distribution Only]
On Thu, Nov 21, 2019 at 11:47:15PM +0800, Zhu, Changfeng wrote:
> From: changzhu <Changfeng.Zhu at amd.com>
>
> It may lose gpuvm invalidate acknowldege state across power-gating off
> cycle. To avoid this issue in gmc9/gmc10 invalidation, add semaphore
> acquire before invalidation and semaphore release after invalidation.
>
> After adding semaphore acquire before invalidation, the semaphore
> register become read-only if another process try to acquire semaphore.
> Then it will not be able to release this semaphore. Then it may cause
> deadlock problem. If this deadlock problem happens, it needs a
> semaphore firmware fix.
>
> Change-Id: I9942a2f451265c1f1038ccfe2f70042c7c8118af
Please remove the chang-id, we don't do gerrit review.
> Signed-off-by: changzhu <Changfeng.Zhu at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c | 52
> ++++++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c | 52 ++++++++++++++++++++++++++
> drivers/gpu/drm/amd/amdgpu/soc15.h | 4 +-
> 3 files changed, 106 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
> b/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
> index af2615ba52aa..e0104b985c42 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
> @@ -234,6 +234,27 @@ static void gmc_v10_0_flush_vm_hub(struct amdgpu_device *adev, uint32_t vmid,
> const unsigned eng = 17;
> unsigned int i;
>
> + spin_lock(&adev->gmc.invalidate_lock);
> + /*
> + * It may lose gpuvm invalidate acknowldege state across power-gating
> + * off cycle, add semaphore acquire before invalidation and semaphore
> + * release after invalidation to avoid entering power gated state
> + * to WA the Issue
> + */
Please add the TODO here, and mention you will continue working on debugging with semaphore for GFXHUB as well. And remove the checking once you addressed the issue with CP designer.
And the comments should be added before all checking here for "MMHUB".
With that fixed, the patch is Acked-by: Huang Rui <ray.huang at amd.com>
> + if (vmhub == AMDGPU_MMHUB_0 ||
> + vmhub == AMDGPU_MMHUB_1) {
> + for (i = 0; i < adev->usec_timeout; i++) {
> + /* a read return value of 1 means semaphore acuqire */
> + tmp = RREG32_NO_KIQ(hub->vm_inv_eng0_sem + eng);
> + if (tmp & 0x1)
> + break;
> + udelay(1);
> + }
> +
> + if (i >= adev->usec_timeout)
> + DRM_ERROR("Timeout waiting for sem acquire in VM flush!\n");
> + }
> +
> WREG32_NO_KIQ(hub->vm_inv_eng0_req + eng, tmp);
>
> /*
> @@ -253,6 +274,16 @@ static void gmc_v10_0_flush_vm_hub(struct amdgpu_device *adev, uint32_t vmid,
> udelay(1);
> }
>
> + /*
> + * add semaphore release after invalidation,
> + * write with 0 means semaphore release
> + */
> + if (vmhub == AMDGPU_MMHUB_0 ||
> + vmhub == AMDGPU_MMHUB_1)
> + WREG32_NO_KIQ(hub->vm_inv_eng0_sem + eng, 0);
> +
> + spin_unlock(&adev->gmc.invalidate_lock);
> +
> if (i < adev->usec_timeout)
> return;
>
> @@ -338,6 +369,19 @@ static uint64_t gmc_v10_0_emit_flush_gpu_tlb(struct amdgpu_ring *ring,
> uint32_t req = gmc_v10_0_get_invalidate_req(vmid, 0);
> unsigned eng = ring->vm_inv_eng;
>
> + /*
> + * It may lose gpuvm invalidate acknowldege state across power-gating
> + * off cycle, add semaphore acquire before invalidation and semaphore
> + * release after invalidation to avoid entering power gated state
> + * to WA the Issue
> + */
> +
> + /* a read return value of 1 means semaphore acuqire */
> + if (ring->funcs->vmhub == AMDGPU_MMHUB_0 ||
> + ring->funcs->vmhub == AMDGPU_MMHUB_1)
> + amdgpu_ring_emit_reg_wait(ring,
> + hub->vm_inv_eng0_sem + eng, 0x1, 0x1);
> +
> amdgpu_ring_emit_wreg(ring, hub->ctx0_ptb_addr_lo32 + (2 * vmid),
> lower_32_bits(pd_addr));
>
> @@ -348,6 +392,14 @@ static uint64_t gmc_v10_0_emit_flush_gpu_tlb(struct amdgpu_ring *ring,
> hub->vm_inv_eng0_ack + eng,
> req, 1 << vmid);
>
> + /*
> + * add semaphore release after invalidation,
> + * write with 0 means semaphore release
> + */
> + if (ring->funcs->vmhub == AMDGPU_MMHUB_0 ||
> + ring->funcs->vmhub == AMDGPU_MMHUB_1)
> + amdgpu_ring_emit_wreg(ring, hub->vm_inv_eng0_sem + eng, 0);
> +
> return pd_addr;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> index b7f2b184e9b8..816fdd602c85 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> @@ -455,6 +455,27 @@ static void gmc_v9_0_flush_gpu_tlb(struct amdgpu_device *adev, uint32_t vmid,
> }
>
> spin_lock(&adev->gmc.invalidate_lock);
> +
> + /*
> + * It may lose gpuvm invalidate acknowldege state across power-gating
> + * off cycle, add semaphore acquire before invalidation and semaphore
> + * release after invalidation to avoid entering power gated state
> + * to WA the Issue
> + */
> + if (vmhub == AMDGPU_MMHUB_0 ||
> + vmhub == AMDGPU_MMHUB_1) {
> + for (j = 0; j < adev->usec_timeout; j++) {
> + /* a read return value of 1 means semaphore acuqire */
> + tmp = RREG32_NO_KIQ(hub->vm_inv_eng0_sem + eng);
> + if (tmp & 0x1)
> + break;
> + udelay(1);
> + }
> +
> + if (j >= adev->usec_timeout)
> + DRM_ERROR("Timeout waiting for sem acquire in VM flush!\n");
> + }
> +
> WREG32_NO_KIQ(hub->vm_inv_eng0_req + eng, tmp);
>
> /*
> @@ -470,7 +491,17 @@ static void gmc_v9_0_flush_gpu_tlb(struct amdgpu_device *adev, uint32_t vmid,
> break;
> udelay(1);
> }
> +
> + /*
> + * add semaphore release after invalidation,
> + * write with 0 means semaphore release
> + */
> + if (vmhub == AMDGPU_MMHUB_0 ||
> + vmhub == AMDGPU_MMHUB_1)
> + WREG32_NO_KIQ(hub->vm_inv_eng0_sem + eng, 0);
> +
> spin_unlock(&adev->gmc.invalidate_lock);
> +
> if (j < adev->usec_timeout)
> return;
>
> @@ -485,6 +516,19 @@ static uint64_t gmc_v9_0_emit_flush_gpu_tlb(struct amdgpu_ring *ring,
> uint32_t req = gmc_v9_0_get_invalidate_req(vmid, 0);
> unsigned eng = ring->vm_inv_eng;
>
> + /*
> + * It may lose gpuvm invalidate acknowldege state across power-gating
> + * off cycle, add semaphore acquire before invalidation and semaphore
> + * release after invalidation to avoid entering power gated state
> + * to WA the Issue
> + */
> +
> + /* a read return value of 1 means semaphore acuqire */
> + if (ring->funcs->vmhub == AMDGPU_MMHUB_0 ||
> + ring->funcs->vmhub == AMDGPU_MMHUB_1)
> + amdgpu_ring_emit_reg_wait(ring,
> + hub->vm_inv_eng0_sem + eng, 0x1, 0x1);
> +
> amdgpu_ring_emit_wreg(ring, hub->ctx0_ptb_addr_lo32 + (2 * vmid),
> lower_32_bits(pd_addr));
>
> @@ -495,6 +539,14 @@ static uint64_t gmc_v9_0_emit_flush_gpu_tlb(struct amdgpu_ring *ring,
> hub->vm_inv_eng0_ack + eng,
> req, 1 << vmid);
>
> + /*
> + * add semaphore release after invalidation,
> + * write with 0 means semaphore release
> + */
> + if (ring->funcs->vmhub == AMDGPU_MMHUB_0 ||
> + ring->funcs->vmhub == AMDGPU_MMHUB_1)
> + amdgpu_ring_emit_wreg(ring, hub->vm_inv_eng0_sem + eng, 0);
> +
> return pd_addr;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/soc15.h
> b/drivers/gpu/drm/amd/amdgpu/soc15.h
> index 344280b869c4..d0fb7a67c1a3 100644
> --- a/drivers/gpu/drm/amd/amdgpu/soc15.h
> +++ b/drivers/gpu/drm/amd/amdgpu/soc15.h
> @@ -28,8 +28,8 @@
> #include "nbio_v7_0.h"
> #include "nbio_v7_4.h"
>
> -#define SOC15_FLUSH_GPU_TLB_NUM_WREG 4
> -#define SOC15_FLUSH_GPU_TLB_NUM_REG_WAIT 1
> +#define SOC15_FLUSH_GPU_TLB_NUM_WREG 6
> +#define SOC15_FLUSH_GPU_TLB_NUM_REG_WAIT 3
>
> extern const struct amd_ip_funcs soc15_common_ip_funcs;
>
> --
> 2.17.1
>
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