From: Sebastian Andrzej Siewior Date: Thu, 21 Sep 2023 16:15:16 +0200 Subject: [PATCH 5/5] drm/amd/display: Move the memory allocation out of dcn20_validate_bandwidth_fp(). Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz dcn20_validate_bandwidth_fp() is invoked while FPU access has been enabled. FPU access requires disabling preemption even on PREEMPT_RT. It is not possible to allocate memory with disabled preemption even with GFP_ATOMIC on PREEMPT_RT. Move the memory allocation before FPU access is enabled. To preserve previous "clean" state of "pipes" add a memset() before the second invocation of dcn20_validate_bandwidth_internal() where the variable is used. Link: https://lore.kernel.org/r/20230921141516.520471-6-bigeasy@linutronix.de Signed-off-by: Sebastian Andrzej Siewior --- drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c | 10 +++++++++- drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.c | 16 +++++++--------- drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.h | 5 ++--- 3 files changed, 18 insertions(+), 13 deletions(-) --- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c +++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c @@ -2141,9 +2141,17 @@ bool dcn20_validate_bandwidth(struct dc bool fast_validate) { bool voltage_supported; + display_e2e_pipe_params_st *pipes; + + pipes = kcalloc(dc->res_pool->pipe_count, sizeof(display_e2e_pipe_params_st), GFP_KERNEL); + if (!pipes) + return false; + DC_FP_START(); - voltage_supported = dcn20_validate_bandwidth_fp(dc, context, fast_validate); + voltage_supported = dcn20_validate_bandwidth_fp(dc, context, fast_validate, pipes); DC_FP_END(); + + kfree(pipes); return voltage_supported; } --- a/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.c +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.c @@ -1910,7 +1910,7 @@ void dcn20_patch_bounding_box(struct dc } static bool dcn20_validate_bandwidth_internal(struct dc *dc, struct dc_state *context, - bool fast_validate) + bool fast_validate, display_e2e_pipe_params_st *pipes) { bool out = false; @@ -1919,7 +1919,6 @@ static bool dcn20_validate_bandwidth_int int vlevel = 0; int pipe_split_from[MAX_PIPES]; int pipe_cnt = 0; - display_e2e_pipe_params_st *pipes = kzalloc(dc->res_pool->pipe_count * sizeof(display_e2e_pipe_params_st), GFP_ATOMIC); DC_LOGGER_INIT(dc->ctx->logger); BW_VAL_TRACE_COUNT(); @@ -1954,16 +1953,14 @@ static bool dcn20_validate_bandwidth_int out = false; validate_out: - kfree(pipes); BW_VAL_TRACE_FINISH(); return out; } -bool dcn20_validate_bandwidth_fp(struct dc *dc, - struct dc_state *context, - bool fast_validate) +bool dcn20_validate_bandwidth_fp(struct dc *dc, struct dc_state *context, + bool fast_validate, display_e2e_pipe_params_st *pipes) { bool voltage_supported = false; bool full_pstate_supported = false; @@ -1982,11 +1979,11 @@ bool dcn20_validate_bandwidth_fp(struct ASSERT(context != dc->current_state); if (fast_validate) { - return dcn20_validate_bandwidth_internal(dc, context, true); + return dcn20_validate_bandwidth_internal(dc, context, true, pipes); } // Best case, we support full UCLK switch latency - voltage_supported = dcn20_validate_bandwidth_internal(dc, context, false); + voltage_supported = dcn20_validate_bandwidth_internal(dc, context, false, pipes); full_pstate_supported = context->bw_ctx.bw.dcn.clk.p_state_change_support; if (context->bw_ctx.dml.soc.dummy_pstate_latency_us == 0 || @@ -1998,7 +1995,8 @@ bool dcn20_validate_bandwidth_fp(struct // Fallback: Try to only support G6 temperature read latency context->bw_ctx.dml.soc.dram_clock_change_latency_us = context->bw_ctx.dml.soc.dummy_pstate_latency_us; - voltage_supported = dcn20_validate_bandwidth_internal(dc, context, false); + memset(pipes, 0, dc->res_pool->pipe_count * sizeof(display_e2e_pipe_params_st)); + voltage_supported = dcn20_validate_bandwidth_internal(dc, context, false, pipes); dummy_pstate_supported = context->bw_ctx.bw.dcn.clk.p_state_change_support; if (voltage_supported && (dummy_pstate_supported || !(context->stream_count))) { --- a/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.h +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.h @@ -61,9 +61,8 @@ void dcn20_update_bounding_box(struct dc unsigned int num_states); void dcn20_patch_bounding_box(struct dc *dc, struct _vcs_dpi_soc_bounding_box_st *bb); -bool dcn20_validate_bandwidth_fp(struct dc *dc, - struct dc_state *context, - bool fast_validate); +bool dcn20_validate_bandwidth_fp(struct dc *dc, struct dc_state *context, + bool fast_validate, display_e2e_pipe_params_st *pipes); void dcn20_fpu_set_wm_ranges(int i, struct pp_smu_wm_range_sets *ranges, struct _vcs_dpi_soc_bounding_box_st *loaded_bb);