diff options
author | Rodrigo Siqueira <Rodrigo.Siqueira@amd.com> | 2021-07-26 20:52:47 -0400 |
---|---|---|
committer | Alex Deucher <alexander.deucher@amd.com> | 2021-08-05 21:17:59 -0400 |
commit | 2d8471dc371f36fd6ba3b5a4716b39555169df3d (patch) | |
tree | cbb6b48333aab9b8d55ba1e287f3f0edf7f37798 | |
parent | 96ee63730fa30614e943ac352ef772be49a712d9 (diff) | |
download | linux-stable-2d8471dc371f36fd6ba3b5a4716b39555169df3d.tar.gz linux-stable-2d8471dc371f36fd6ba3b5a4716b39555169df3d.tar.bz2 linux-stable-2d8471dc371f36fd6ba3b5a4716b39555169df3d.zip |
drm/amd/display: Add control mechanism for FPU utilization
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 or
exit too early. For avoiding this situation, this commit adds a
mechanism where dc_fpu_begin/end manages the access to
kernel_fpu_begin/end.
Change since V3:
- Rebase
Change since V2:
- Christian: Do not use this_cpu_* between get/put_cpu_ptr().
Change since V1:
- Use a better variable names
- Use get_cpu_ptr and put_cpu_ptr to better balance preemption enable
and disable
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Anson Jacob <Anson.Jacob@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Hersen Wu <hersenxs.wu@amd.com>
Cc: Aric Cyr <aric.cyr@amd.com>
Cc: Jun Lei <jun.lei@amd.com>
Cc: Dmytro Laktyushkin <dmytro.laktyushkin@amd.com>
Cc: Qingqing Zhuo <qingqing.zhuo@amd.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
-rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_trace.h | 13 | ||||
-rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c | 77 | ||||
-rw-r--r-- | drivers/gpu/drm/amd/display/dc/dc_trace.h | 4 |
3 files changed, 63 insertions, 31 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..fdcaea22b456 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 recursion_depth), + TP_ARGS(begin, function, line, recursion_depth), TP_STRUCT__entry( __field(bool, begin) __field(const char *, function) __field(int, line) + __field(int, recursion_depth) ), TP_fast_assign( __entry->begin = begin; __entry->function = function; __entry->line = line; + __entry->recursion_depth = recursion_depth; ), - TP_printk("%s()+%d: %s", + TP_printk("%s: recursion_depth: %d: %s()+%d:", + __entry->begin ? "begin" : "end", + __entry->recursion_depth, __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 d4ab27bf8d04..33807d746e76 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c @@ -34,6 +34,19 @@ #endif /** + * DOC: DC FPU manipulation 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(int, fpu_recursion_depth); + +/** * dc_fpu_begin - Enables FPU protection * @function_name: A string containing the function name for debug purposes * (usually __func__) @@ -48,22 +61,30 @@ */ void dc_fpu_begin(const char *function_name, const int line) { - TRACE_DCN_FPU(true, function_name, line); + int *pcpu; + + pcpu = get_cpu_ptr(&fpu_recursion_depth); + *pcpu += 1; + if (*pcpu == 1) { #if defined(CONFIG_X86) - kernel_fpu_begin(); + kernel_fpu_begin(); #elif defined(CONFIG_PPC64) - if (cpu_has_feature(CPU_FTR_VSX_COMP)) { - preempt_disable(); - enable_kernel_vsx(); - } else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { - preempt_disable(); - enable_kernel_altivec(); - } else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { - preempt_disable(); - enable_kernel_fp(); - } + if (cpu_has_feature(CPU_FTR_VSX_COMP)) { + preempt_disable(); + enable_kernel_vsx(); + } else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { + preempt_disable(); + enable_kernel_altivec(); + } else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { + preempt_disable(); + enable_kernel_fp(); + } #endif + } + + TRACE_DCN_FPU(true, function_name, line, *pcpu); + put_cpu_ptr(&fpu_recursion_depth); } /** @@ -78,19 +99,27 @@ 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); + int *pcpu; + + pcpu = get_cpu_ptr(&fpu_recursion_depth); + *pcpu -= 1; + if (*pcpu <= 0) { #if defined(CONFIG_X86) - kernel_fpu_end(); + kernel_fpu_end(); #elif defined(CONFIG_PPC64) - if (cpu_has_feature(CPU_FTR_VSX_COMP)) { - disable_kernel_vsx(); - preempt_enable(); - } else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { - disable_kernel_altivec(); - preempt_enable(); - } else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { - disable_kernel_fp(); - preempt_enable(); - } + if (cpu_has_feature(CPU_FTR_VSX_COMP)) { + disable_kernel_vsx(); + preempt_enable(); + } else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { + disable_kernel_altivec(); + preempt_enable(); + } else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { + disable_kernel_fp(); + preempt_enable(); + } #endif + } + + TRACE_DCN_FPU(false, function_name, line, *pcpu); + put_cpu_ptr(&fpu_recursion_depth); } 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) |