<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> </head> <body> <div> <div> <div style="color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" dir="ltr"> Ping…</div> </div> <div id="ms-outlook-mobile-signature"> <div></div> </div> </div> <hr style="display:inline-block;width:98%" tabindex="-1"> <div id="divRplyFwdMsg" dir="ltr">From: ricetons@gmail.com <ricetons@gmail.com> Sent: Saturday, April 30, 2022 3:34:00 PM To: amd-gfx@lists.freedesktop.org <amd-gfx@lists.freedesktop.org> Cc: lang.yu@amd.com <lang.yu@amd.com>; ckoenig.leichtzumerken@gmail.com <ckoenig.leichtzumerken@gmail.com>; Guchun.Chen@amd.com <Guchun.Chen@amd.com>; yifan1.zhang@amd.com <yifan1.zhang@amd.com>; Hawking.Zhang@amd.com <Hawking.Zhang@amd.com>; Haohui Mai <ricetons@gmail.com> Subject: [PATCH v6] drm/amdgpu: Ensure the DMA engine is deactivated during set ups <div> </div> </div> <div class="BodyFragment"> <div class="PlainText">From: Haohui Mai <ricetons@gmail.com> The patch fully deactivates the DMA engine before setting up the ring buffer to avoid potential data races and crashes. Signed-off-by: Haohui Mai <ricetons@gmail.com> --- drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c | 109 +++++++++++++++---------- 1 file changed, 64 insertions(+), 45 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c b/drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c index 013d2dec81d0..1fac9d8e99de 100644 --- a/drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c +++ b/drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c @@ -459,7 +459,6 @@ static void sdma_v5_2_ring_emit_fence(struct amdgpu_ring *ring, u64 addr, u64 se } } - /** * sdma_v5_2_gfx_stop - stop the gfx async dma engines * @@ -505,17 +504,21 @@ static void sdma_v5_2_rlc_stop(struct amdgpu_device *adev) } /** - * sdma_v5_2_ctx_switch_enable - stop the async dma engines context switch + * sdma_v5_2_ctx_switch_enable_for_instance - start the async dma engines + * context switch for an instance * * @adev: amdgpu_device pointer - * @enable: enable/disable the DMA MEs context switch. + * @instance_idx: the index of the SDMA instance * - * Halt or unhalt the async dma engines context switch. + * Unhalt the async dma engines context switch. */ -static void sdma_v5_2_ctx_switch_enable(struct amdgpu_device *adev, bool enable) +static void sdma_v5_2_ctx_switch_enable_for_instance(struct amdgpu_device *adev, int instance_idx) { u32 f32_cntl, phase_quantum = 0; - int i; + + if (WARN_ON(instance_idx >= adev->sdma.num_instances)) { + return; + } if (amdgpu_sdma_phase_quantum) { unsigned value = amdgpu_sdma_phase_quantum; @@ -539,50 +542,68 @@ static void sdma_v5_2_ctx_switch_enable(struct amdgpu_device *adev, bool enable) phase_quantum = value << SDMA0_PHASE0_QUANTUM__VALUE__SHIFT | unit << SDMA0_PHASE0_QUANTUM__UNIT__SHIFT; - } - - for (i = 0; i < adev->sdma.num_instances; i++) { - if (enable && amdgpu_sdma_phase_quantum) { - WREG32_SOC15_IP(GC, sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_PHASE0_QUANTUM), - phase_quantum); - WREG32_SOC15_IP(GC, sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_PHASE1_QUANTUM), - phase_quantum); - WREG32_SOC15_IP(GC, sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_PHASE2_QUANTUM), - phase_quantum); - } - if (!amdgpu_sriov_vf(adev)) { - f32_cntl = RREG32(sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_CNTL)); - f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL, - AUTO_CTXSW_ENABLE, enable ? 1 : 0); - WREG32(sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_CNTL), f32_cntl); - } + WREG32_SOC15_IP(GC, + sdma_v5_2_get_reg_offset(adev, instance_idx, mmSDMA0_PHASE0_QUANTUM), + phase_quantum); + WREG32_SOC15_IP(GC, + sdma_v5_2_get_reg_offset(adev, instance_idx, mmSDMA0_PHASE1_QUANTUM), + phase_quantum); + WREG32_SOC15_IP(GC, + sdma_v5_2_get_reg_offset(adev, instance_idx, mmSDMA0_PHASE2_QUANTUM), + phase_quantum); } + if (!amdgpu_sriov_vf(adev)) { + f32_cntl = RREG32(sdma_v5_2_get_reg_offset(adev, instance_idx, mmSDMA0_CNTL)); + f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL, + AUTO_CTXSW_ENABLE, 1); + WREG32(sdma_v5_2_get_reg_offset(adev, instance_idx, mmSDMA0_CNTL), f32_cntl); + } } /** - * sdma_v5_2_enable - stop the async dma engines + * sdma_v5_2_ctx_switch_disable_all - stop the async dma engines context switch * * @adev: amdgpu_device pointer - * @enable: enable/disable the DMA MEs. * - * Halt or unhalt the async dma engines. + * Halt the async dma engines context switch. */ -static void sdma_v5_2_enable(struct amdgpu_device *adev, bool enable) +static void sdma_v5_2_ctx_switch_disable_all(struct amdgpu_device *adev) { u32 f32_cntl; int i; - if (!enable) { - sdma_v5_2_gfx_stop(adev); - sdma_v5_2_rlc_stop(adev); + if (amdgpu_sriov_vf(adev)) + return; + + for (i = 0; i < adev->sdma.num_instances; i++) { + f32_cntl = RREG32(sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_CNTL)); + f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL, + AUTO_CTXSW_ENABLE, 0); + WREG32(sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_CNTL), f32_cntl); } +} + +/** + * sdma_v5_2_halt - stop the async dma engines + * + * @adev: amdgpu_device pointer + * + * Halt the async dma engines. + */ +static void sdma_v5_2_halt(struct amdgpu_device *adev) +{ + int i; + u32 f32_cntl; + + sdma_v5_2_gfx_stop(adev); + sdma_v5_2_rlc_stop(adev); if (!amdgpu_sriov_vf(adev)) { for (i = 0; i < adev->sdma.num_instances; i++) { f32_cntl = RREG32(sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_F32_CNTL)); - f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_F32_CNTL, HALT, enable ? 0 : 1); + f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_F32_CNTL, HALT, 1); WREG32(sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_F32_CNTL), f32_cntl); } } @@ -594,6 +615,9 @@ static void sdma_v5_2_enable(struct amdgpu_device *adev, bool enable) * @adev: amdgpu_device pointer * * Set up the gfx DMA ring buffers and enable them. + * It assumes that the dma engine is stopped for each instance. + * The function enables the engine and preemptions sequentially for each instance. + * * Returns 0 for success, error for failure. */ static int sdma_v5_2_gfx_resume(struct amdgpu_device *adev) @@ -737,10 +761,7 @@ static int sdma_v5_2_gfx_resume(struct amdgpu_device *adev) ring->sched.ready = true; - if (amdgpu_sriov_vf(adev)) { /* bare-metal sequence doesn't need below to lines */ - sdma_v5_2_ctx_switch_enable(adev, true); - sdma_v5_2_enable(adev, true); - } + sdma_v5_2_ctx_switch_enable_for_instance(adev, i); r = amdgpu_ring_test_ring(ring); if (r) { @@ -784,7 +805,7 @@ static int sdma_v5_2_load_microcode(struct amdgpu_device *adev) int i, j; /* halt the MEs */ - sdma_v5_2_enable(adev, false); + sdma_v5_2_halt(adev); for (i = 0; i < adev->sdma.num_instances; i++) { if (!adev->sdma.instance[i].fw) @@ -856,8 +877,8 @@ static int sdma_v5_2_start(struct amdgpu_device *adev) int r = 0; if (amdgpu_sriov_vf(adev)) { - sdma_v5_2_ctx_switch_enable(adev, false); - sdma_v5_2_enable(adev, false); + sdma_v5_2_ctx_switch_disable_all(adev); + sdma_v5_2_halt(adev); /* set RB registers */ r = sdma_v5_2_gfx_resume(adev); @@ -881,12 +902,10 @@ static int sdma_v5_2_start(struct amdgpu_device *adev) amdgpu_gfx_off_ctrl(adev, false); sdma_v5_2_soft_reset(adev); - /* unhalt the MEs */ - sdma_v5_2_enable(adev, true); - /* enable sdma ring preemption */ - sdma_v5_2_ctx_switch_enable(adev, true); - /* start the gfx rings and rlc compute queues */ + /* Soft reset supposes to disable the dma engine and preemption. + * Now start the gfx rings and rlc compute queues. + */ r = sdma_v5_2_gfx_resume(adev); if (adev->in_s0ix) amdgpu_gfx_off_ctrl(adev, true); @@ -1340,8 +1359,8 @@ static int sdma_v5_2_hw_fini(void *handle) if (amdgpu_sriov_vf(adev)) return 0; - sdma_v5_2_ctx_switch_enable(adev, false); - sdma_v5_2_enable(adev, false); + sdma_v5_2_ctx_switch_disable_all(adev); + sdma_v5_2_halt(adev); return 0; } -- 2.25.1 </div> </div> </body> </html>