DC invokes DC_FPU_START/END in multiple parts of the code; this can create a situation where we invoke this FPU operation in a nested way. For avoiding this situation, this commit adds a mechanism where dc_fpu_begin/end manages the access to kernel_fpu_begin/end.
Signed-off-by: Rodrigo Siqueira Rodrigo.Siqueira@amd.com Acked-by: Rodrigo Siqueira Rodrigo.Siqueira@amd.com --- .../amd/display/amdgpu_dm/amdgpu_dm_trace.h | 13 ++++--- .../gpu/drm/amd/display/amdgpu_dm/dc_fpu.c | 34 ++++++++++++++++--- drivers/gpu/drm/amd/display/dc/dc_trace.h | 4 +-- 3 files changed, 40 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_trace.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_trace.h index 230bb12c405e..cd4f0d3f37fb 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_trace.h +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_trace.h @@ -638,23 +638,26 @@ TRACE_EVENT(amdgpu_refresh_rate_track, );
TRACE_EVENT(dcn_fpu, - TP_PROTO(bool begin, const char *function, const int line), - TP_ARGS(begin, function, line), + TP_PROTO(bool begin, const char *function, const int line, const int ref_count), + TP_ARGS(begin, function, line, ref_count),
TP_STRUCT__entry( __field(bool, begin) __field(const char *, function) __field(int, line) + __field(int, ref_count) ), TP_fast_assign( __entry->begin = begin; __entry->function = function; __entry->line = line; + __entry->ref_count = ref_count; ), - TP_printk("%s()+%d: %s", + TP_printk("%s: ref_count: %d: %s()+%d:", + __entry->begin ? "begin" : "end", + __entry->ref_count, __entry->function, - __entry->line, - __entry->begin ? "begin" : "end" + __entry->line ) );
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c index ff34007509de..5dcefe193523 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c @@ -28,6 +28,19 @@
#include <asm/fpu/api.h>
+/** + * DOC: Overview + * + * DC core uses FPU operations in multiple parts of the code, which requires a + * more specialized way to manage these areas' entrance. To fulfill this + * requirement, we created some wrapper functions that encapsulate + * kernel_fpu_begin/end to better fit our need in the display component. In + * summary, in this file, you can find functions related to FPU operation + * management. + */ + +static DEFINE_PER_CPU(atomic_t, fpu_ref); + /** * dc_fpu_begin - Enables FPU protection * @function_name: A string containing the function name for debug purposes @@ -40,8 +53,14 @@ */ void dc_fpu_begin(const char *function_name, const int line) { - TRACE_DCN_FPU(true, function_name, line); - kernel_fpu_begin(); + int ret; + atomic_t *local_fpu_ref = this_cpu_ptr(&fpu_ref); + + ret = atomic_inc_return(local_fpu_ref); + TRACE_DCN_FPU(true, function_name, line, ret); + + if (ret == 1) + kernel_fpu_begin(); }
/** @@ -56,6 +75,13 @@ void dc_fpu_begin(const char *function_name, const int line) */ void dc_fpu_end(const char *function_name, const int line) { - TRACE_DCN_FPU(false, function_name, line); - kernel_fpu_end(); + + int ret; + atomic_t *local_fpu_ref = this_cpu_ptr(&fpu_ref); + + ret = atomic_dec_return(local_fpu_ref); + TRACE_DCN_FPU(false, function_name, line, ret); + + if (!ret) + kernel_fpu_end(); } diff --git a/drivers/gpu/drm/amd/display/dc/dc_trace.h b/drivers/gpu/drm/amd/display/dc/dc_trace.h index d598ba697e45..c711797e5c9e 100644 --- a/drivers/gpu/drm/amd/display/dc/dc_trace.h +++ b/drivers/gpu/drm/amd/display/dc/dc_trace.h @@ -38,5 +38,5 @@ #define TRACE_DCN_CLOCK_STATE(dcn_clocks) \ trace_amdgpu_dm_dc_clocks_state(dcn_clocks)
-#define TRACE_DCN_FPU(begin, function, line) \ - trace_dcn_fpu(begin, function, line) +#define TRACE_DCN_FPU(begin, function, line, ref_count) \ + trace_dcn_fpu(begin, function, line, ref_count)