From 43ca8efa46d9b1c4defa1b27c4dd1ef3866aaad9 Mon Sep 17 00:00:00 2001 From: pding Date: Fri, 13 Oct 2017 15:38:35 +0800 Subject: [PATCH] drm/amdgpu: busywait KIQ register accessing (v4) MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Register accessing is performed when IRQ is disabled. Never sleep in this function. Known issue: dead sleep in many use cases of index/data registers. v2: - wrap polling fence functions. - don't trigger IRQ for polling in case of wrongly fence signal. v3: - handle wrap round gracefully. - add comments for polling function v4: - don't return negative timeout confused with error code Signed-off-by: pding Reviewed-by: Christian König Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 8 +--- drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 50 ++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 4 ++ drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c | 30 ++++++------- 6 files changed, 71 insertions(+), 25 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index b8ba1f5ae5e7..cbcb6a153aba 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -879,7 +879,7 @@ struct amdgpu_mec { struct amdgpu_kiq { u64 eop_gpu_addr; struct amdgpu_bo *eop_obj; - struct mutex ring_mutex; + spinlock_t ring_lock; struct amdgpu_ring ring; struct amdgpu_irq_src irq; }; diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index 3a6ce6386ad0..0b9332e65a4c 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -109,10 +109,8 @@ uint32_t amdgpu_mm_rreg(struct amdgpu_device *adev, uint32_t reg, { uint32_t ret; - if (!(acc_flags & AMDGPU_REGS_NO_KIQ) && amdgpu_sriov_runtime(adev)) { - BUG_ON(in_interrupt()); + if (!(acc_flags & AMDGPU_REGS_NO_KIQ) && amdgpu_sriov_runtime(adev)) return amdgpu_virt_kiq_rreg(adev, reg); - } if ((reg * 4) < adev->rmmio_size && !(acc_flags & AMDGPU_REGS_IDX)) ret = readl(((void __iomem *)adev->rmmio) + (reg * 4)); @@ -137,10 +135,8 @@ void amdgpu_mm_wreg(struct amdgpu_device *adev, uint32_t reg, uint32_t v, adev->last_mm_index = v; } - if (!(acc_flags & AMDGPU_REGS_NO_KIQ) && amdgpu_sriov_runtime(adev)) { - BUG_ON(in_interrupt()); + if (!(acc_flags & AMDGPU_REGS_NO_KIQ) && amdgpu_sriov_runtime(adev)) return amdgpu_virt_kiq_wreg(adev, reg, v); - } if ((reg * 4) < adev->rmmio_size && !(acc_flags & AMDGPU_REGS_IDX)) writel(v, ((void __iomem *)adev->rmmio) + (reg * 4)); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index 7bdedd788f5a..fb9f88ef6059 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -168,6 +168,32 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f) return 0; } +/** + * amdgpu_fence_emit_polling - emit a fence on the requeste ring + * + * @ring: ring the fence is associated with + * @s: resulting sequence number + * + * Emits a fence command on the requested ring (all asics). + * Used For polling fence. + * Returns 0 on success, -ENOMEM on failure. + */ +int amdgpu_fence_emit_polling(struct amdgpu_ring *ring, uint32_t *s) +{ + uint32_t seq; + + if (!s) + return -EINVAL; + + seq = ++ring->fence_drv.sync_seq; + amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr, + seq, AMDGPU_FENCE_FLAG_INT); + + *s = seq; + + return 0; +} + /** * amdgpu_fence_schedule_fallback - schedule fallback check * @@ -281,6 +307,30 @@ int amdgpu_fence_wait_empty(struct amdgpu_ring *ring) return r; } +/** + * amdgpu_fence_wait_polling - busy wait for givn sequence number + * + * @ring: ring index the fence is associated with + * @wait_seq: sequence number to wait + * @timeout: the timeout for waiting in usecs + * + * Wait for all fences on the requested ring to signal (all asics). + * Returns left time if no timeout, 0 or minus if timeout. + */ +signed long amdgpu_fence_wait_polling(struct amdgpu_ring *ring, + uint32_t wait_seq, + signed long timeout) +{ + uint32_t seq; + + do { + seq = amdgpu_fence_read(ring); + udelay(5); + timeout -= 5; + } while ((int32_t)(wait_seq - seq) > 0 && timeout > 0); + + return timeout > 0 ? timeout : 0; +} /** * amdgpu_fence_count_emitted - get the count of emitted fences * diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index 83435ccbad44..ef043361009f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -201,7 +201,7 @@ int amdgpu_gfx_kiq_init_ring(struct amdgpu_device *adev, struct amdgpu_kiq *kiq = &adev->gfx.kiq; int r = 0; - mutex_init(&kiq->ring_mutex); + spin_lock_init(&kiq->ring_lock); r = amdgpu_wb_get(adev, &adev->virt.reg_val_offs); if (r) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h index 0d9ce141404c..b18c2b96691f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h @@ -90,8 +90,12 @@ int amdgpu_fence_driver_start_ring(struct amdgpu_ring *ring, void amdgpu_fence_driver_suspend(struct amdgpu_device *adev); void amdgpu_fence_driver_resume(struct amdgpu_device *adev); int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **fence); +int amdgpu_fence_emit_polling(struct amdgpu_ring *ring, uint32_t *s); void amdgpu_fence_process(struct amdgpu_ring *ring); int amdgpu_fence_wait_empty(struct amdgpu_ring *ring); +signed long amdgpu_fence_wait_polling(struct amdgpu_ring *ring, + uint32_t wait_seq, + signed long timeout); unsigned amdgpu_fence_count_emitted(struct amdgpu_ring *ring); /* diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c index ed7be2eb24b0..e97f80f86005 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c @@ -22,7 +22,7 @@ */ #include "amdgpu.h" -#define MAX_KIQ_REG_WAIT 100000 +#define MAX_KIQ_REG_WAIT 100000000 /* in usecs */ int amdgpu_allocate_static_csa(struct amdgpu_device *adev) { @@ -114,27 +114,24 @@ void amdgpu_virt_init_setting(struct amdgpu_device *adev) uint32_t amdgpu_virt_kiq_rreg(struct amdgpu_device *adev, uint32_t reg) { signed long r; - uint32_t val; - struct dma_fence *f; + uint32_t val, seq; struct amdgpu_kiq *kiq = &adev->gfx.kiq; struct amdgpu_ring *ring = &kiq->ring; BUG_ON(!ring->funcs->emit_rreg); - mutex_lock(&kiq->ring_mutex); + spin_lock(&kiq->ring_lock); amdgpu_ring_alloc(ring, 32); amdgpu_ring_emit_rreg(ring, reg); - amdgpu_fence_emit(ring, &f); + amdgpu_fence_emit_polling(ring, &seq); amdgpu_ring_commit(ring); - mutex_unlock(&kiq->ring_mutex); + spin_unlock(&kiq->ring_lock); - r = dma_fence_wait_timeout(f, false, msecs_to_jiffies(MAX_KIQ_REG_WAIT)); - dma_fence_put(f); + r = amdgpu_fence_wait_polling(ring, seq, MAX_KIQ_REG_WAIT); if (r < 1) { - DRM_ERROR("wait for kiq fence error: %ld.\n", r); + DRM_ERROR("wait for kiq fence error: %ld\n", r); return ~0; } - val = adev->wb.wb[adev->virt.reg_val_offs]; return val; @@ -143,23 +140,22 @@ uint32_t amdgpu_virt_kiq_rreg(struct amdgpu_device *adev, uint32_t reg) void amdgpu_virt_kiq_wreg(struct amdgpu_device *adev, uint32_t reg, uint32_t v) { signed long r; - struct dma_fence *f; + uint32_t seq; struct amdgpu_kiq *kiq = &adev->gfx.kiq; struct amdgpu_ring *ring = &kiq->ring; BUG_ON(!ring->funcs->emit_wreg); - mutex_lock(&kiq->ring_mutex); + spin_lock(&kiq->ring_lock); amdgpu_ring_alloc(ring, 32); amdgpu_ring_emit_wreg(ring, reg, v); - amdgpu_fence_emit(ring, &f); + amdgpu_fence_emit_polling(ring, &seq); amdgpu_ring_commit(ring); - mutex_unlock(&kiq->ring_mutex); + spin_unlock(&kiq->ring_lock); - r = dma_fence_wait_timeout(f, false, msecs_to_jiffies(MAX_KIQ_REG_WAIT)); + r = amdgpu_fence_wait_polling(ring, seq, MAX_KIQ_REG_WAIT); if (r < 1) - DRM_ERROR("wait for kiq fence error: %ld.\n", r); - dma_fence_put(f); + DRM_ERROR("wait for kiq fence error: %ld\n", r); } /** -- 2.30.2