Commit 96ee6373 authored by Rodrigo Siqueira's avatar Rodrigo Siqueira Committed by Alex Deucher
Browse files

drm/amd/display: Add control mechanism for FPU 



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:
- Christian: Move PPC64 code to dc_fpu_begin/end.

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>
Signed-off-by: default avatarRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent c8b3538d

drivers/gpu/drm/amd/display/amdgpu_dm/Makefile

+4 −0
Original line number Diff line number Diff line
@@ -27,6 +27,10 @@ 


AMDGPUDM = amdgpu_dm.o amdgpu_dm_irq.o amdgpu_dm_mst_types.o amdgpu_dm_color.o



ifdef CONFIG_DRM_AMD_DC_DCN

AMDGPUDM += dc_fpu.o

endif



ifneq ($(CONFIG_DRM_AMD_DC),)

AMDGPUDM += amdgpu_dm_services.o amdgpu_dm_helpers.o amdgpu_dm_pp_smu.o amdgpu_dm_psr.o

endif

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_trace.h

+21 −0
Original line number Diff line number Diff line
@@ -637,6 +637,27 @@ TRACE_EVENT(amdgpu_refresh_rate_track, 
		  __entry->refresh_rate_ns)

);



TRACE_EVENT(dcn_fpu,

	    TP_PROTO(bool begin, const char *function, const int line),

	    TP_ARGS(begin, function, line),



	    TP_STRUCT__entry(

			     __field(bool, begin)

			     __field(const char *, function)

			     __field(int, line)

	    ),

	    TP_fast_assign(

			   __entry->begin = begin;

			   __entry->function = function;

			   __entry->line = line;

	    ),

	    TP_printk("%s()+%d: %s",

		      __entry->function,

		      __entry->line,

		      __entry->begin ? "begin" : "end"

	    )

);



#endif /* _AMDGPU_DM_TRACE_H_ */



#undef TRACE_INCLUDE_PATH

drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c

0 → 100644
+96 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: MIT

/*

 * Copyright 2021 Advanced Micro Devices, Inc.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the "Software"),

 * to deal in the Software without restriction, including without limitation

 * the rights to use, copy, modify, merge, publish, distribute, sublicense,

 * and/or sell copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL

 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR

 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,

 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

 * OTHER DEALINGS IN THE SOFTWARE.

 *

 * Authors: AMD

 *

 */



#include "dc_trace.h"



#if defined(CONFIG_X86)

#include <asm/fpu/api.h>

#elif defined(CONFIG_PPC64)

#include <asm/switch_to.h>

#include <asm/cputable.h>

#endif



/**

 * dc_fpu_begin - Enables FPU protection

 * @function_name: A string containing the function name for debug purposes

 *   (usually __func__)

 *

 * @line: A line number where DC_FP_START was invoked for debug purpose

 *   (usually __LINE__)

 *

 * This function is responsible for managing the use of kernel_fpu_begin() with

 * the advantage of providing an event trace for debugging.

 *

 * Note: Do not call this function directly; always use DC_FP_START().

 */

void dc_fpu_begin(const char *function_name, const int line)

{

	TRACE_DCN_FPU(true, function_name, line);



#if defined(CONFIG_X86)

	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();

	}

#endif

}



/**

 * dc_fpu_end - Disable FPU protection

 * @function_name: A string containing the function name for debug purposes

 * @line: A-line number where DC_FP_END was invoked for debug purpose

 *

 * This function is responsible for managing the use of kernel_fpu_end() with

 * the advantage of providing an event trace for debugging.

 *

 * Note: Do not call this function directly; always use DC_FP_END().

 */

void dc_fpu_end(const char *function_name, const int line)

{

	TRACE_DCN_FPU(false, function_name, line);

#if defined(CONFIG_X86)

	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();

	}

#endif

}

drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.h

0 → 100644
+33 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: MIT */

/*

 * Copyright 2021 Advanced Micro Devices, Inc.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the "Software"),

 * to deal in the Software without restriction, including without limitation

 * the rights to use, copy, modify, merge, publish, distribute, sublicense,

 * and/or sell copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL

 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR

 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,

 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

 * OTHER DEALINGS IN THE SOFTWARE.

 *

 * Authors: AMD

 *

 */



#ifndef __DC_FPU_H__

#define __DC_FPU_H__



void dc_fpu_begin(const char *function_name, const int line);

void dc_fpu_end(const char *function_name, const int line);



#endif /* __DC_FPU_H__ */

drivers/gpu/drm/amd/display/dc/dc_trace.h

+3 −0
Original line number Diff line number Diff line
@@ -37,3 +37,6 @@ 


#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)