2021-09-09 01:05:41

by Harry Wentland

[permalink] [raw]
Subject: [PATCH 4/4] drm/amd/display: Allocate structs needed by dcn_bw_calc_rq_dlg_ttu in pipe_ctx

[Why & How]
dcn_bw_calc_rq_dlg_ttu uses a stack frame great than 1024. To solve this
we could allocate the rq_param, dlg_sys_param, and input structs
dynamically. Since this function is inside a kernel_fpu_begin()/end()
call we want to avoid memory allocation. Instead it's much
safer to pre-allocate these on the pipe_ctx.

Signed-off-by: Harry Wentland <[email protected]>
Fixes: 3fe617ccafd6 ("Enable '-Werror' by default for all kernel builds")
Cc: Nick Desaulniers <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: [email protected]
Cc: Linux Kernel Mailing List <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Leo Li <[email protected]>
Cc: Alex Deucher <[email protected]>
Cc: Christian König <[email protected]>
Cc: Xinhui Pan <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: [email protected]
---
.../gpu/drm/amd/display/dc/calcs/dcn_calcs.c | 61 ++++++++++---------
.../gpu/drm/amd/display/dc/inc/core_types.h | 3 +
2 files changed, 35 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/calcs/dcn_calcs.c b/drivers/gpu/drm/amd/display/dc/calcs/dcn_calcs.c
index 8e3a9294be3a..6b248cd2a461 100644
--- a/drivers/gpu/drm/amd/display/dc/calcs/dcn_calcs.c
+++ b/drivers/gpu/drm/amd/display/dc/calcs/dcn_calcs.c
@@ -459,9 +459,9 @@ static void dcn_bw_calc_rq_dlg_ttu(
struct _vcs_dpi_display_dlg_regs_st *dlg_regs = &pipe->dlg_regs;
struct _vcs_dpi_display_ttu_regs_st *ttu_regs = &pipe->ttu_regs;
struct _vcs_dpi_display_rq_regs_st *rq_regs = &pipe->rq_regs;
- struct _vcs_dpi_display_rq_params_st rq_param = {0};
- struct _vcs_dpi_display_dlg_sys_params_st dlg_sys_param = {0};
- struct _vcs_dpi_display_e2e_pipe_params_st input = { { { 0 } } };
+ struct _vcs_dpi_display_rq_params_st *rq_param = &pipe->dml_rq_param;
+ struct _vcs_dpi_display_dlg_sys_params_st *dlg_sys_param = &pipe->dml_dlg_sys_param;
+ struct _vcs_dpi_display_e2e_pipe_params_st *input = &pipe->dml_input;
float total_active_bw = 0;
float total_prefetch_bw = 0;
int total_flip_bytes = 0;
@@ -470,47 +470,50 @@ static void dcn_bw_calc_rq_dlg_ttu(
memset(dlg_regs, 0, sizeof(*dlg_regs));
memset(ttu_regs, 0, sizeof(*ttu_regs));
memset(rq_regs, 0, sizeof(*rq_regs));
+ memset(rq_param, 0, sizeof(*rq_param));
+ memset(dlg_sys_param, 0, sizeof(*dlg_sys_param));
+ memset(input, 0, sizeof(*input));

for (i = 0; i < number_of_planes; i++) {
total_active_bw += v->read_bandwidth[i];
total_prefetch_bw += v->prefetch_bandwidth[i];
total_flip_bytes += v->total_immediate_flip_bytes[i];
}
- dlg_sys_param.total_flip_bw = v->return_bw - dcn_bw_max2(total_active_bw, total_prefetch_bw);
- if (dlg_sys_param.total_flip_bw < 0.0)
- dlg_sys_param.total_flip_bw = 0;
-
- dlg_sys_param.t_mclk_wm_us = v->dram_clock_change_watermark;
- dlg_sys_param.t_sr_wm_us = v->stutter_enter_plus_exit_watermark;
- dlg_sys_param.t_urg_wm_us = v->urgent_watermark;
- dlg_sys_param.t_extra_us = v->urgent_extra_latency;
- dlg_sys_param.deepsleep_dcfclk_mhz = v->dcf_clk_deep_sleep;
- dlg_sys_param.total_flip_bytes = total_flip_bytes;
-
- pipe_ctx_to_e2e_pipe_params(pipe, &input.pipe);
- input.clks_cfg.dcfclk_mhz = v->dcfclk;
- input.clks_cfg.dispclk_mhz = v->dispclk;
- input.clks_cfg.dppclk_mhz = v->dppclk;
- input.clks_cfg.refclk_mhz = dc->res_pool->ref_clocks.dchub_ref_clock_inKhz / 1000.0;
- input.clks_cfg.socclk_mhz = v->socclk;
- input.clks_cfg.voltage = v->voltage_level;
+ dlg_sys_param->total_flip_bw = v->return_bw - dcn_bw_max2(total_active_bw, total_prefetch_bw);
+ if (dlg_sys_param->total_flip_bw < 0.0)
+ dlg_sys_param->total_flip_bw = 0;
+
+ dlg_sys_param->t_mclk_wm_us = v->dram_clock_change_watermark;
+ dlg_sys_param->t_sr_wm_us = v->stutter_enter_plus_exit_watermark;
+ dlg_sys_param->t_urg_wm_us = v->urgent_watermark;
+ dlg_sys_param->t_extra_us = v->urgent_extra_latency;
+ dlg_sys_param->deepsleep_dcfclk_mhz = v->dcf_clk_deep_sleep;
+ dlg_sys_param->total_flip_bytes = total_flip_bytes;
+
+ pipe_ctx_to_e2e_pipe_params(pipe, &input->pipe);
+ input->clks_cfg.dcfclk_mhz = v->dcfclk;
+ input->clks_cfg.dispclk_mhz = v->dispclk;
+ input->clks_cfg.dppclk_mhz = v->dppclk;
+ input->clks_cfg.refclk_mhz = dc->res_pool->ref_clocks.dchub_ref_clock_inKhz / 1000.0;
+ input->clks_cfg.socclk_mhz = v->socclk;
+ input->clks_cfg.voltage = v->voltage_level;
// dc->dml.logger = pool->base.logger;
- input.dout.output_format = (v->output_format[in_idx] == dcn_bw_420) ? dm_420 : dm_444;
- input.dout.output_type = (v->output[in_idx] == dcn_bw_hdmi) ? dm_hdmi : dm_dp;
+ input->dout.output_format = (v->output_format[in_idx] == dcn_bw_420) ? dm_420 : dm_444;
+ input->dout.output_type = (v->output[in_idx] == dcn_bw_hdmi) ? dm_hdmi : dm_dp;
//input[in_idx].dout.output_standard;

/*todo: soc->sr_enter_plus_exit_time??*/
- dlg_sys_param.t_srx_delay_us = dc->dcn_ip->dcfclk_cstate_latency / v->dcf_clk_deep_sleep;
+ dlg_sys_param->t_srx_delay_us = dc->dcn_ip->dcfclk_cstate_latency / v->dcf_clk_deep_sleep;

- dml1_rq_dlg_get_rq_params(dml, &rq_param, &input.pipe.src);
- dml1_extract_rq_regs(dml, rq_regs, &rq_param);
+ dml1_rq_dlg_get_rq_params(dml, rq_param, &input->pipe.src);
+ dml1_extract_rq_regs(dml, rq_regs, rq_param);
dml1_rq_dlg_get_dlg_params(
dml,
dlg_regs,
ttu_regs,
- &rq_param.dlg,
- &dlg_sys_param,
- &input,
+ &rq_param->dlg,
+ dlg_sys_param,
+ input,
true,
true,
v->pte_enable == dcn_bw_yes,
diff --git a/drivers/gpu/drm/amd/display/dc/inc/core_types.h b/drivers/gpu/drm/amd/display/dc/inc/core_types.h
index 45a6216dfa2a..4dca14b598dd 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/core_types.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/core_types.h
@@ -366,6 +366,9 @@ struct pipe_ctx {
struct _vcs_dpi_display_ttu_regs_st ttu_regs;
struct _vcs_dpi_display_rq_regs_st rq_regs;
struct _vcs_dpi_display_pipe_dest_params_st pipe_dlg_param;
+ struct _vcs_dpi_display_rq_params_st dml_rq_param;
+ struct _vcs_dpi_display_dlg_sys_params_st dml_dlg_sys_param;
+ struct _vcs_dpi_display_e2e_pipe_params_st dml_input;
int det_buffer_size_kb;
bool unbounded_req;
#endif
--
2.33.0