[PATCH v4 2/4] drm/amd/display: Add control mechanism for FPU
Christian König
christian.koenig at amd.com
Tue Jul 27 06:57:50 UTC 2021
Am 27.07.21 um 02:52 schrieb Rodrigo Siqueira:
> 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 at amd.com>
> Cc: Anson Jacob <Anson.Jacob at amd.com>
> Cc: Christian König <christian.koenig at amd.com>
> Cc: Hersen Wu <hersenxs.wu at amd.com>
> Cc: Aric Cyr <aric.cyr at amd.com>
> Cc: Jun Lei <jun.lei at amd.com>
> Cc: Dmytro Laktyushkin <dmytro.laktyushkin at amd.com>
> Cc: Qingqing Zhuo <qingqing.zhuo at amd.com>
> Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira at amd.com>
Reviewed-by: Christian König <christian.koenig at amd.com>
> ---
> .../gpu/drm/amd/display/amdgpu_dm/Makefile | 4 +
> .../amd/display/amdgpu_dm/amdgpu_dm_trace.h | 21 ++++
> .../gpu/drm/amd/display/amdgpu_dm/dc_fpu.c | 96 +++++++++++++++++++
> .../gpu/drm/amd/display/amdgpu_dm/dc_fpu.h | 33 +++++++
> drivers/gpu/drm/amd/display/dc/dc_trace.h | 3 +
> drivers/gpu/drm/amd/display/dc/os_types.h | 35 +------
> 6 files changed, 160 insertions(+), 32 deletions(-)
> create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
> create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.h
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/Makefile b/drivers/gpu/drm/amd/display/amdgpu_dm/Makefile
> index 91fb72c96545..718e123a3230 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/Makefile
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/Makefile
> @@ -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
> 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 46a33f64cf8e..230bb12c405e 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
> @@ -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
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
> new file mode 100644
> index 000000000000..d4ab27bf8d04
> --- /dev/null
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
> @@ -0,0 +1,96 @@
> +// 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
> +}
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.h b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.h
> new file mode 100644
> index 000000000000..fb54983c5c60
> --- /dev/null
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.h
> @@ -0,0 +1,33 @@
> +/* 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__ */
> diff --git a/drivers/gpu/drm/amd/display/dc/dc_trace.h b/drivers/gpu/drm/amd/display/dc/dc_trace.h
> index d2615357269b..d598ba697e45 100644
> --- a/drivers/gpu/drm/amd/display/dc/dc_trace.h
> +++ b/drivers/gpu/drm/amd/display/dc/dc_trace.h
> @@ -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)
> diff --git a/drivers/gpu/drm/amd/display/dc/os_types.h b/drivers/gpu/drm/amd/display/dc/os_types.h
> index 126c2f3a4dd3..f50cae252de4 100644
> --- a/drivers/gpu/drm/amd/display/dc/os_types.h
> +++ b/drivers/gpu/drm/amd/display/dc/os_types.h
> @@ -51,38 +51,9 @@
> #define dm_error(fmt, ...) DRM_ERROR(fmt, ##__VA_ARGS__)
>
> #if defined(CONFIG_DRM_AMD_DC_DCN)
> -#if defined(CONFIG_X86)
> -#include <asm/fpu/api.h>
> -#define DC_FP_START() kernel_fpu_begin()
> -#define DC_FP_END() kernel_fpu_end()
> -#elif defined(CONFIG_PPC64)
> -#include <asm/switch_to.h>
> -#include <asm/cputable.h>
> -#define DC_FP_START() { \
> - 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(); \
> - } \
> -}
> -#define DC_FP_END() { \
> - 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
> +#include "amdgpu_dm/dc_fpu.h"
> +#define DC_FP_START() dc_fpu_begin(__func__, __LINE__)
> +#define DC_FP_END() dc_fpu_end(__func__, __LINE__)
> #endif
>
> /*
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