drm/amd/display: Fix unsafe uses of kernel mode FPU

The point of isolating code that uses kernel mode FPU in separate
compilation units is to ensure that even implicit uses of, e.g., SIMD
registers for spilling occur only in a context where this is permitted,
i.e., from inside a kernel_fpu_begin/end block.

This is important on arm64, which uses -mgeneral-regs-only to build all
kernel code, with the exception of such compilation units where FP or
SIMD registers are expected to be used. Given that the compiler may
invent uses of FP/SIMD anywhere in such a unit, none of its code may be
accessible from outside a kernel_fpu_begin/end block.

This means that all callers into such compilation units must use the
DC_FP start/end macros, which must not occur there themselves. For
robustness, all functions with external linkage that reside there should
call dc_assert_fp_enabled() to assert that the FPU context was set up
correctly.

Fix this for the DCN35, DCN351 and DCN36 implementations.

Cc: Austin Zheng <austin.zheng@amd.com>
Cc: Jun Lei <jun.lei@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Rodrigo Siqueira <siqueira@igalia.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn31/dcn31_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn31/dcn31_fpu.c
index 17a21bcbde17220225f6a932027a18c49a5fb000..1a28061bb9ff77d431352a4663afc73627552b3b 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn31/dcn31_fpu.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn31/dcn31_fpu.c
@@ -808,6 +808,8 @@ void dcn316_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_param
 
 int dcn_get_max_non_odm_pix_rate_100hz(struct _vcs_dpi_soc_bounding_box_st *soc)
 {
+       dc_assert_fp_enabled();
+
        return soc->clock_limits[0].dispclk_mhz * 10000.0 / (1.0 + soc->dcn_downspread_percent / 100.0);
 }
 
@@ -815,6 +817,8 @@ int dcn_get_approx_det_segs_required_for_pstate(
                struct _vcs_dpi_soc_bounding_box_st *soc,
                int pix_clk_100hz, int bpp, int seg_size_kb)
 {
+       dc_assert_fp_enabled();
+
        /* Roughly calculate required crb to hide latency. In practice there is slightly
         * more buffer available for latency hiding
         */

diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn35/dcn35_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn35/dcn35_fpu.c
index c9dd920744c92893b682098501de4a33b10adb65..817a370e80a7704fc74210321acd67dfde5e7cb7 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn35/dcn35_fpu.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn35/dcn35_fpu.c
@@ -445,6 +445,8 @@ int dcn35_populate_dml_pipes_from_context_fpu(struct dc *dc,
        bool upscaled = false;
        const unsigned int max_allowed_vblank_nom = 1023;
 
+       dc_assert_fp_enabled();
+
        dcn31_populate_dml_pipes_from_context(dc, context, pipes,
                                              validate_mode);
 
@@ -498,9 +500,7 @@ int dcn35_populate_dml_pipes_from_context_fpu(struct dc *dc,
 
                pipes[pipe_cnt].pipe.src.unbounded_req_mode = false;
 
-               DC_FP_START();
                dcn31_zero_pipe_dcc_fraction(pipes, pipe_cnt);
-               DC_FP_END();
 
                pipes[pipe_cnt].pipe.dest.vfront_porch = timing->v_front_porch;
                pipes[pipe_cnt].pipe.src.dcc_rate = 3;
@@ -581,6 +581,8 @@ void dcn35_decide_zstate_support(struct dc *dc, struct dc_state *context)
        unsigned int i, plane_count = 0;
        DC_LOGGER_INIT(dc->ctx->logger);
 
+       dc_assert_fp_enabled();
+
        for (i = 0; i < dc->res_pool->pipe_count; i++) {
                if (context->res_ctx.pipe_ctx[i].plane_state)
                        plane_count++;

diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn351/dcn351_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn351/dcn351_fpu.c
index 8cda18ce1a760be816427feb130480b1dbc392e9..77023b619f1e0ba58b6c3127e6c5e9782a0882bc 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn351/dcn351_fpu.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn351/dcn351_fpu.c
@@ -478,6 +478,8 @@ int dcn351_populate_dml_pipes_from_context_fpu(struct dc *dc,
        bool upscaled = false;
        const unsigned int max_allowed_vblank_nom = 1023;
 
+       dc_assert_fp_enabled();
+
        dcn31_populate_dml_pipes_from_context(dc, context, pipes,
                                              validate_mode);
 
@@ -531,9 +533,7 @@ int dcn351_populate_dml_pipes_from_context_fpu(struct dc *dc,
 
                pipes[pipe_cnt].pipe.src.unbounded_req_mode = false;
 
-               DC_FP_START();
                dcn31_zero_pipe_dcc_fraction(pipes, pipe_cnt);
-               DC_FP_END();
 
                pipes[pipe_cnt].pipe.dest.vfront_porch = timing->v_front_porch;
                pipes[pipe_cnt].pipe.src.dcc_rate = 3;

diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c
index 07552445e424f895c8b0dd3787a011a28115f185..fff57f23f4f7ab3bb867b7bfa70fd5430e98ebb5 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c
@@ -1760,6 +1760,20 @@ enum dc_status dcn35_patch_unknown_plane_state(struct dc_plane_state *plane_stat
 }
 
 
+static int populate_dml_pipes_from_context_fpu(struct dc *dc,
+                                              struct dc_state *context,
+                                              display_e2e_pipe_params_st *pipes,
+                                              enum dc_validate_mode validate_mode)
+{
+       int ret;
+
+       DC_FP_START();
+       ret = dcn35_populate_dml_pipes_from_context_fpu(dc, context, pipes, validate_mode);
+       DC_FP_END();
+
+       return ret;
+}
+
 static struct resource_funcs dcn35_res_pool_funcs = {
        .destroy = dcn35_destroy_resource_pool,
        .link_enc_create = dcn35_link_encoder_create,
@@ -1770,7 +1784,7 @@ static struct resource_funcs dcn35_res_pool_funcs = {
        .validate_bandwidth = dcn35_validate_bandwidth,
        .calculate_wm_and_dlg = NULL,
        .update_soc_for_wm_a = dcn31_update_soc_for_wm_a,
-       .populate_dml_pipes = dcn35_populate_dml_pipes_from_context_fpu,
+       .populate_dml_pipes = populate_dml_pipes_from_context_fpu,
        .acquire_free_pipe_as_secondary_dpp_pipe = dcn20_acquire_free_pipe_for_layer,
        .release_pipe = dcn20_release_pipe,
        .add_stream_to_ctx = dcn30_add_stream_to_ctx,

diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c
index cb0478a9a34da50d339ae2650d4e752e348adae9..0abd163b425e53bec9eceab7edaffae775d03960 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c
@@ -1732,6 +1732,21 @@ static enum dc_status dcn351_validate_bandwidth(struct dc *dc,
        return out ? DC_OK : DC_FAIL_BANDWIDTH_VALIDATE;
 }
 
+static int populate_dml_pipes_from_context_fpu(struct dc *dc,
+                                              struct dc_state *context,
+                                              display_e2e_pipe_params_st *pipes,
+                                              enum dc_validate_mode validate_mode)
+{
+       int ret;
+
+       DC_FP_START();
+       ret = dcn351_populate_dml_pipes_from_context_fpu(dc, context, pipes, validate_mode);
+       DC_FP_END();
+
+       return ret;
+
+}
+
 static struct resource_funcs dcn351_res_pool_funcs = {
        .destroy = dcn351_destroy_resource_pool,
        .link_enc_create = dcn35_link_encoder_create,
@@ -1742,7 +1757,7 @@ static struct resource_funcs dcn351_res_pool_funcs = {
        .validate_bandwidth = dcn351_validate_bandwidth,
        .calculate_wm_and_dlg = NULL,
        .update_soc_for_wm_a = dcn31_update_soc_for_wm_a,
-       .populate_dml_pipes = dcn351_populate_dml_pipes_from_context_fpu,
+       .populate_dml_pipes = populate_dml_pipes_from_context_fpu,
        .acquire_free_pipe_as_secondary_dpp_pipe = dcn20_acquire_free_pipe_for_layer,
        .release_pipe = dcn20_release_pipe,
        .add_stream_to_ctx = dcn30_add_stream_to_ctx,

diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn36/dcn36_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dcn36/dcn36_resource.c
index 126090c9bb8a84a290ce48d1c74a7a30c5f28c2e..ca125ee6c2fb35665adf95d8dec997544a70e5d3 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn36/dcn36_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn36/dcn36_resource.c
@@ -1734,6 +1734,20 @@ static enum dc_status dcn35_validate_bandwidth(struct dc *dc,
 }
 
 
+static int populate_dml_pipes_from_context_fpu(struct dc *dc,
+                                              struct dc_state *context,
+                                              display_e2e_pipe_params_st *pipes,
+                                              enum dc_validate_mode validate_mode)
+{
+       int ret;
+
+       DC_FP_START();
+       ret = dcn35_populate_dml_pipes_from_context_fpu(dc, context, pipes, validate_mode);
+       DC_FP_END();
+
+       return ret;
+}
+
 static struct resource_funcs dcn36_res_pool_funcs = {
        .destroy = dcn36_destroy_resource_pool,
        .link_enc_create = dcn35_link_encoder_create,
@@ -1744,7 +1758,7 @@ static struct resource_funcs dcn36_res_pool_funcs = {
        .validate_bandwidth = dcn35_validate_bandwidth,
        .calculate_wm_and_dlg = NULL,
        .update_soc_for_wm_a = dcn31_update_soc_for_wm_a,
-       .populate_dml_pipes = dcn35_populate_dml_pipes_from_context_fpu,
+       .populate_dml_pipes = populate_dml_pipes_from_context_fpu,
        .acquire_free_pipe_as_secondary_dpp_pipe = dcn20_acquire_free_pipe_for_layer,
        .release_pipe = dcn20_release_pipe,
        .add_stream_to_ctx = dcn30_add_stream_to_ctx,