Set a configurable SDMA phase quantum when enabling SDMA context switching. The default value significantly reduces SDMA latency in page table updates when user-mode SDMA queues have concurrent activity, compared to the initial HW setting.
Signed-off-by: Felix Kuehling <[email protected]> --- drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 + drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 4 ++++ drivers/gpu/drm/amd/amdgpu/cik_sdma.c | 32 ++++++++++++++++++++++++++++++- drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c | 32 ++++++++++++++++++++++++++++++- drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c | 34 ++++++++++++++++++++++++++++++++- 5 files changed, 100 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 810796a..2129fbb 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -106,6 +106,7 @@ extern unsigned amdgpu_pcie_lane_cap; extern unsigned amdgpu_cg_mask; extern unsigned amdgpu_pg_mask; +extern unsigned amdgpu_sdma_phase_quantum; extern char *amdgpu_disable_cu; extern char *amdgpu_virtual_display; extern unsigned amdgpu_pp_feature_mask; diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 4bf4a80..02cf24e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -107,6 +107,7 @@ unsigned amdgpu_pcie_lane_cap = 0; unsigned amdgpu_cg_mask = 0xffffffff; unsigned amdgpu_pg_mask = 0xffffffff; +unsigned amdgpu_sdma_phase_quantum = 32; char *amdgpu_disable_cu = NULL; char *amdgpu_virtual_display = NULL; unsigned amdgpu_pp_feature_mask = 0xffffffff; @@ -223,6 +224,9 @@ MODULE_PARM_DESC(pg_mask, "Powergating flags mask (0 = disable power gating)"); module_param_named(pg_mask, amdgpu_pg_mask, uint, 0444); +MODULE_PARM_DESC(sdma_phase_quantum, "SDMA context switch phase quantum (x 1K GPU clock cycles, 0 = no change (default 32))"); +module_param_named(sdma_phase_quantum, amdgpu_sdma_phase_quantum, uint, 0444); + MODULE_PARM_DESC(disable_cu, "Disable CUs (se.sh.cu,...)"); module_param_named(disable_cu, amdgpu_disable_cu, charp, 0444); diff --git a/drivers/gpu/drm/amd/amdgpu/cik_sdma.c b/drivers/gpu/drm/amd/amdgpu/cik_sdma.c index 4a9cea0..f508f4d 100644 --- a/drivers/gpu/drm/amd/amdgpu/cik_sdma.c +++ b/drivers/gpu/drm/amd/amdgpu/cik_sdma.c @@ -351,14 +351,44 @@ static void cik_sdma_rlc_stop(struct amdgpu_device *adev) */ static void cik_ctx_switch_enable(struct amdgpu_device *adev, bool enable) { - u32 f32_cntl; + u32 f32_cntl, phase_quantum = 0; int i; + if (amdgpu_sdma_phase_quantum) { + unsigned value = amdgpu_sdma_phase_quantum; + unsigned unit = 0; + + while (value > (SDMA0_PHASE0_QUANTUM__VALUE_MASK >> + SDMA0_PHASE0_QUANTUM__VALUE__SHIFT)) { + value = (value + 1) >> 1; + unit++; + } + if (unit > (SDMA0_PHASE0_QUANTUM__UNIT_MASK >> + SDMA0_PHASE0_QUANTUM__UNIT__SHIFT)) { + value = (SDMA0_PHASE0_QUANTUM__VALUE_MASK >> + SDMA0_PHASE0_QUANTUM__VALUE__SHIFT); + unit = (SDMA0_PHASE0_QUANTUM__UNIT_MASK >> + SDMA0_PHASE0_QUANTUM__UNIT__SHIFT); + WARN_ONCE(1, + "clamping sdma_phase_quantum to %uK clock cycles\n", + value << unit); + } + phase_quantum = + value << SDMA0_PHASE0_QUANTUM__VALUE__SHIFT | + unit << SDMA0_PHASE0_QUANTUM__UNIT__SHIFT; + } + for (i = 0; i < adev->sdma.num_instances; i++) { f32_cntl = RREG32(mmSDMA0_CNTL + sdma_offsets[i]); if (enable) { f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL, AUTO_CTXSW_ENABLE, 1); + if (amdgpu_sdma_phase_quantum) { + WREG32(mmSDMA0_PHASE0_QUANTUM + sdma_offsets[i], + phase_quantum); + WREG32(mmSDMA0_PHASE1_QUANTUM + sdma_offsets[i], + phase_quantum); + } } else { f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL, AUTO_CTXSW_ENABLE, 0); diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c b/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c index 67a29fb..b1de44f 100644 --- a/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c +++ b/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c @@ -551,9 +551,33 @@ static void sdma_v3_0_rlc_stop(struct amdgpu_device *adev) */ static void sdma_v3_0_ctx_switch_enable(struct amdgpu_device *adev, bool enable) { - u32 f32_cntl; + u32 f32_cntl, phase_quantum = 0; int i; + if (amdgpu_sdma_phase_quantum) { + unsigned value = amdgpu_sdma_phase_quantum; + unsigned unit = 0; + + while (value > (SDMA0_PHASE0_QUANTUM__VALUE_MASK >> + SDMA0_PHASE0_QUANTUM__VALUE__SHIFT)) { + value = (value + 1) >> 1; + unit++; + } + if (unit > (SDMA0_PHASE0_QUANTUM__UNIT_MASK >> + SDMA0_PHASE0_QUANTUM__UNIT__SHIFT)) { + value = (SDMA0_PHASE0_QUANTUM__VALUE_MASK >> + SDMA0_PHASE0_QUANTUM__VALUE__SHIFT); + unit = (SDMA0_PHASE0_QUANTUM__UNIT_MASK >> + SDMA0_PHASE0_QUANTUM__UNIT__SHIFT); + WARN_ONCE(1, + "clamping sdma_phase_quantum to %uK clock cycles\n", + value << unit); + } + phase_quantum = + value << SDMA0_PHASE0_QUANTUM__VALUE__SHIFT | + unit << SDMA0_PHASE0_QUANTUM__UNIT__SHIFT; + } + for (i = 0; i < adev->sdma.num_instances; i++) { f32_cntl = RREG32(mmSDMA0_CNTL + sdma_offsets[i]); if (enable) { @@ -561,6 +585,12 @@ static void sdma_v3_0_ctx_switch_enable(struct amdgpu_device *adev, bool enable) AUTO_CTXSW_ENABLE, 1); f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL, ATC_L1_ENABLE, 1); + if (amdgpu_sdma_phase_quantum) { + WREG32(mmSDMA0_PHASE0_QUANTUM + sdma_offsets[i], + phase_quantum); + WREG32(mmSDMA0_PHASE1_QUANTUM + sdma_offsets[i], + phase_quantum); + } } else { f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL, AUTO_CTXSW_ENABLE, 0); diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c index 4a65697..591f3e7 100644 --- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c +++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c @@ -493,13 +493,45 @@ static void sdma_v4_0_rlc_stop(struct amdgpu_device *adev) */ static void sdma_v4_0_ctx_switch_enable(struct amdgpu_device *adev, bool enable) { - u32 f32_cntl; + u32 f32_cntl, phase_quantum = 0; int i; + if (amdgpu_sdma_phase_quantum) { + unsigned value = amdgpu_sdma_phase_quantum; + unsigned unit = 0; + + while (value > (SDMA0_PHASE0_QUANTUM__VALUE_MASK >> + SDMA0_PHASE0_QUANTUM__VALUE__SHIFT)) { + value = (value + 1) >> 1; + unit++; + } + if (unit > (SDMA0_PHASE0_QUANTUM__UNIT_MASK >> + SDMA0_PHASE0_QUANTUM__UNIT__SHIFT)) { + value = (SDMA0_PHASE0_QUANTUM__VALUE_MASK >> + SDMA0_PHASE0_QUANTUM__VALUE__SHIFT); + unit = (SDMA0_PHASE0_QUANTUM__UNIT_MASK >> + SDMA0_PHASE0_QUANTUM__UNIT__SHIFT); + WARN_ONCE(1, + "clamping sdma_phase_quantum to %uK clock cycles\n", + value << unit); + } + phase_quantum = + value << SDMA0_PHASE0_QUANTUM__VALUE__SHIFT | + unit << SDMA0_PHASE0_QUANTUM__UNIT__SHIFT; + } + for (i = 0; i < adev->sdma.num_instances; i++) { f32_cntl = RREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_CNTL)); f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL, AUTO_CTXSW_ENABLE, enable ? 1 : 0); + if (enable && amdgpu_sdma_phase_quantum) { + WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_PHASE0_QUANTUM), + phase_quantum); + WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_PHASE1_QUANTUM), + phase_quantum); + WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_PHASE2_QUANTUM), + phase_quantum); + } WREG32(sdma_v4_0_get_reg_offset(i, mmSDMA0_CNTL), f32_cntl); } -- 1.9.1 _______________________________________________ amd-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/amd-gfx
