drm/amd/display: Add control mechanism for FPU utilization

[linux-2.6-microblaze.git] / drivers / gpu / drm / amd / display / amdgpu_dm / dc_fpu.c

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 d4ab27b..33807d7 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
@@ -33,6 +33,19 @@
 #include <asm/cputable.h>
 #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
@@ -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);
 }