From: Anson Jacob <Anson.Jacob@amd.com> To: <mpe@ellerman.id.au>, <benh@kernel.crashing.org>, <paulus@samba.org>, <christophe.leroy@csgroup.eu>, <linuxppc-dev@lists.ozlabs.org>, <amd-gfx@lists.freedesktop.org> Cc: Sunpeng.Li@amd.com, Harry.Wentland@amd.com, qingqing.zhuo@amd.com, Rodrigo.Siqueira@amd.com, roman.li@amd.com, Anson.Jacob@amd.com, Aurabindo.Pillai@amd.com, Bhawanpreet.Lakha@amd.com, bindu.r@amd.com Subject: [RFC 1/2] ppc/fpu: Add generic FPU api similar to x86 Date: Mon, 19 Jul 2021 15:52:10 -0400 [thread overview] Message-ID: <20210719195211.520428-2-Anson.Jacob@amd.com> (raw) In-Reply-To: <20210719195211.520428-1-Anson.Jacob@amd.com> - Add kernel_fpu_begin & kernel_fpu_end API as x86 - Add logic similar to x86 to ensure fpu begin/end call correctness - Add kernel_fpu_enabled to know if FPU is enabled Signed-off-by: Anson Jacob <Anson.Jacob@amd.com> --- arch/powerpc/include/asm/switch_to.h | 29 ++---- arch/powerpc/kernel/process.c | 130 +++++++++++++++++++++++++++ 2 files changed, 137 insertions(+), 22 deletions(-) diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h index 9d1fbd8be1c7..aded7aa661c0 100644 --- a/arch/powerpc/include/asm/switch_to.h +++ b/arch/powerpc/include/asm/switch_to.h @@ -41,10 +41,7 @@ extern void enable_kernel_fp(void); extern void flush_fp_to_thread(struct task_struct *); extern void giveup_fpu(struct task_struct *); extern void save_fpu(struct task_struct *); -static inline void disable_kernel_fp(void) -{ - msr_check_and_clear(MSR_FP); -} +extern void disable_kernel_fp(void); #else static inline void save_fpu(struct task_struct *t) { } static inline void flush_fp_to_thread(struct task_struct *t) { } @@ -55,10 +52,7 @@ extern void enable_kernel_altivec(void); extern void flush_altivec_to_thread(struct task_struct *); extern void giveup_altivec(struct task_struct *); extern void save_altivec(struct task_struct *); -static inline void disable_kernel_altivec(void) -{ - msr_check_and_clear(MSR_VEC); -} +extern void disable_kernel_altivec(void); #else static inline void save_altivec(struct task_struct *t) { } static inline void __giveup_altivec(struct task_struct *t) { } @@ -67,20 +61,7 @@ static inline void __giveup_altivec(struct task_struct *t) { } #ifdef CONFIG_VSX extern void enable_kernel_vsx(void); extern void flush_vsx_to_thread(struct task_struct *); -static inline void disable_kernel_vsx(void) -{ - msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX); -} -#else -static inline void enable_kernel_vsx(void) -{ - BUILD_BUG(); -} - -static inline void disable_kernel_vsx(void) -{ - BUILD_BUG(); -} +extern void disable_kernel_vsx(void); #endif #ifdef CONFIG_SPE @@ -114,4 +95,8 @@ static inline void clear_task_ebb(struct task_struct *t) extern int set_thread_tidr(struct task_struct *t); +bool kernel_fpu_enabled(void); +void kernel_fpu_begin(void); +void kernel_fpu_end(void); + #endif /* _ASM_POWERPC_SWITCH_TO_H */ diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 185beb290580..2ced8c6a3fab 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -75,6 +75,17 @@ #define TM_DEBUG(x...) do { } while(0) #endif +/* + * Track whether the kernel is using the FPU state + * currently. + * + * This flag is used: + * + * - kernel_fpu_begin()/end() correctness + * - kernel_fpu_enabled info + */ +static DEFINE_PER_CPU(bool, in_kernel_fpu); + extern unsigned long _get_SP(void); #ifdef CONFIG_PPC_TRANSACTIONAL_MEM @@ -212,6 +223,9 @@ void enable_kernel_fp(void) unsigned long cpumsr; WARN_ON(preemptible()); + WARN_ON_ONCE(this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, true); cpumsr = msr_check_and_set(MSR_FP); @@ -231,6 +245,15 @@ void enable_kernel_fp(void) } } EXPORT_SYMBOL(enable_kernel_fp); + +void disable_kernel_fp(void) +{ + WARN_ON_ONCE(!this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, false); + msr_check_and_clear(MSR_FP); +} +EXPORT_SYMBOL(disable_kernel_fp); #else static inline void __giveup_fpu(struct task_struct *tsk) { } #endif /* CONFIG_PPC_FPU */ @@ -263,6 +286,9 @@ void enable_kernel_altivec(void) unsigned long cpumsr; WARN_ON(preemptible()); + WARN_ON_ONCE(this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, true); cpumsr = msr_check_and_set(MSR_VEC); @@ -283,6 +309,14 @@ void enable_kernel_altivec(void) } EXPORT_SYMBOL(enable_kernel_altivec); +void disable_kernel_altivec(void) +{ + WARN_ON_ONCE(!this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, false); + msr_check_and_clear(MSR_VEC); +} +EXPORT_SYMBOL(disable_kernel_altivec); /* * Make sure the VMX/Altivec register state in the * the thread_struct is up to date for task tsk. @@ -333,6 +367,9 @@ void enable_kernel_vsx(void) unsigned long cpumsr; WARN_ON(preemptible()); + WARN_ON_ONCE(this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, true); cpumsr = msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX); @@ -354,6 +391,15 @@ void enable_kernel_vsx(void) } EXPORT_SYMBOL(enable_kernel_vsx); +void disable_kernel_vsx(void) +{ + WARN_ON_ONCE(!this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, false); + msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX); +} +EXPORT_SYMBOL(disable_kernel_vsx); + void flush_vsx_to_thread(struct task_struct *tsk) { if (tsk->thread.regs) { @@ -406,6 +452,90 @@ void flush_spe_to_thread(struct task_struct *tsk) } #endif /* CONFIG_SPE */ +static bool fpu_support(void) +{ + if (cpu_has_feature(CPU_FTR_VSX_COMP)) { + return true; + } else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { + return true; + } else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { + return true; + } + + return false; +} + +bool kernel_fpu_enabled(void) +{ + return this_cpu_read(in_kernel_fpu); +} +EXPORT_SYMBOL(kernel_fpu_enabled); + +void kernel_fpu_begin(void) +{ + if (!fpu_support()) { + WARN_ON_ONCE(1); + return; + } + + preempt_disable(); + +#ifdef CONFIG_VSX + if (cpu_has_feature(CPU_FTR_VSX_COMP)) { + enable_kernel_vsx(); + return; + } +#endif + +#ifdef CONFIG_ALTIVEC + if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { + enable_kernel_altivec(); + return; + } +#endif + +#ifdef CONFIG_PPC_FPU + if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { + enable_kernel_fp(); + return; + } +#endif +} +EXPORT_SYMBOL_GPL(kernel_fpu_begin); + +void kernel_fpu_end(void) +{ + if (!fpu_support()) { + WARN_ON_ONCE(1); + return; + } + +#ifdef CONFIG_VSX + if (cpu_has_feature(CPU_FTR_VSX_COMP)) { + disable_kernel_vsx(); + goto done; + } +#endif + +#ifdef CONFIG_ALTIVEC + if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { + disable_kernel_altivec(); + goto done; + } +#endif + +#ifdef CONFIG_PPC_FPU + if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { + disable_kernel_fp(); + goto done; + } +#endif + +done: + preempt_enable(); +} +EXPORT_SYMBOL_GPL(kernel_fpu_end); + static unsigned long msr_all_available; static int __init init_msr_all_available(void) -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Anson Jacob <Anson.Jacob@amd.com> To: <mpe@ellerman.id.au>, <benh@kernel.crashing.org>, <paulus@samba.org>, <christophe.leroy@csgroup.eu>, <linuxppc-dev@lists.ozlabs.org>, <amd-gfx@lists.freedesktop.org> Cc: Sunpeng.Li@amd.com, Harry.Wentland@amd.com, qingqing.zhuo@amd.com, Rodrigo.Siqueira@amd.com, roman.li@amd.com, Anson.Jacob@amd.com, Aurabindo.Pillai@amd.com, Bhawanpreet.Lakha@amd.com, bindu.r@amd.com Subject: [RFC 1/2] ppc/fpu: Add generic FPU api similar to x86 Date: Mon, 19 Jul 2021 15:52:10 -0400 [thread overview] Message-ID: <20210719195211.520428-2-Anson.Jacob@amd.com> (raw) In-Reply-To: <20210719195211.520428-1-Anson.Jacob@amd.com> - Add kernel_fpu_begin & kernel_fpu_end API as x86 - Add logic similar to x86 to ensure fpu begin/end call correctness - Add kernel_fpu_enabled to know if FPU is enabled Signed-off-by: Anson Jacob <Anson.Jacob@amd.com> --- arch/powerpc/include/asm/switch_to.h | 29 ++---- arch/powerpc/kernel/process.c | 130 +++++++++++++++++++++++++++ 2 files changed, 137 insertions(+), 22 deletions(-) diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h index 9d1fbd8be1c7..aded7aa661c0 100644 --- a/arch/powerpc/include/asm/switch_to.h +++ b/arch/powerpc/include/asm/switch_to.h @@ -41,10 +41,7 @@ extern void enable_kernel_fp(void); extern void flush_fp_to_thread(struct task_struct *); extern void giveup_fpu(struct task_struct *); extern void save_fpu(struct task_struct *); -static inline void disable_kernel_fp(void) -{ - msr_check_and_clear(MSR_FP); -} +extern void disable_kernel_fp(void); #else static inline void save_fpu(struct task_struct *t) { } static inline void flush_fp_to_thread(struct task_struct *t) { } @@ -55,10 +52,7 @@ extern void enable_kernel_altivec(void); extern void flush_altivec_to_thread(struct task_struct *); extern void giveup_altivec(struct task_struct *); extern void save_altivec(struct task_struct *); -static inline void disable_kernel_altivec(void) -{ - msr_check_and_clear(MSR_VEC); -} +extern void disable_kernel_altivec(void); #else static inline void save_altivec(struct task_struct *t) { } static inline void __giveup_altivec(struct task_struct *t) { } @@ -67,20 +61,7 @@ static inline void __giveup_altivec(struct task_struct *t) { } #ifdef CONFIG_VSX extern void enable_kernel_vsx(void); extern void flush_vsx_to_thread(struct task_struct *); -static inline void disable_kernel_vsx(void) -{ - msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX); -} -#else -static inline void enable_kernel_vsx(void) -{ - BUILD_BUG(); -} - -static inline void disable_kernel_vsx(void) -{ - BUILD_BUG(); -} +extern void disable_kernel_vsx(void); #endif #ifdef CONFIG_SPE @@ -114,4 +95,8 @@ static inline void clear_task_ebb(struct task_struct *t) extern int set_thread_tidr(struct task_struct *t); +bool kernel_fpu_enabled(void); +void kernel_fpu_begin(void); +void kernel_fpu_end(void); + #endif /* _ASM_POWERPC_SWITCH_TO_H */ diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 185beb290580..2ced8c6a3fab 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -75,6 +75,17 @@ #define TM_DEBUG(x...) do { } while(0) #endif +/* + * Track whether the kernel is using the FPU state + * currently. + * + * This flag is used: + * + * - kernel_fpu_begin()/end() correctness + * - kernel_fpu_enabled info + */ +static DEFINE_PER_CPU(bool, in_kernel_fpu); + extern unsigned long _get_SP(void); #ifdef CONFIG_PPC_TRANSACTIONAL_MEM @@ -212,6 +223,9 @@ void enable_kernel_fp(void) unsigned long cpumsr; WARN_ON(preemptible()); + WARN_ON_ONCE(this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, true); cpumsr = msr_check_and_set(MSR_FP); @@ -231,6 +245,15 @@ void enable_kernel_fp(void) } } EXPORT_SYMBOL(enable_kernel_fp); + +void disable_kernel_fp(void) +{ + WARN_ON_ONCE(!this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, false); + msr_check_and_clear(MSR_FP); +} +EXPORT_SYMBOL(disable_kernel_fp); #else static inline void __giveup_fpu(struct task_struct *tsk) { } #endif /* CONFIG_PPC_FPU */ @@ -263,6 +286,9 @@ void enable_kernel_altivec(void) unsigned long cpumsr; WARN_ON(preemptible()); + WARN_ON_ONCE(this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, true); cpumsr = msr_check_and_set(MSR_VEC); @@ -283,6 +309,14 @@ void enable_kernel_altivec(void) } EXPORT_SYMBOL(enable_kernel_altivec); +void disable_kernel_altivec(void) +{ + WARN_ON_ONCE(!this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, false); + msr_check_and_clear(MSR_VEC); +} +EXPORT_SYMBOL(disable_kernel_altivec); /* * Make sure the VMX/Altivec register state in the * the thread_struct is up to date for task tsk. @@ -333,6 +367,9 @@ void enable_kernel_vsx(void) unsigned long cpumsr; WARN_ON(preemptible()); + WARN_ON_ONCE(this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, true); cpumsr = msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX); @@ -354,6 +391,15 @@ void enable_kernel_vsx(void) } EXPORT_SYMBOL(enable_kernel_vsx); +void disable_kernel_vsx(void) +{ + WARN_ON_ONCE(!this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, false); + msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX); +} +EXPORT_SYMBOL(disable_kernel_vsx); + void flush_vsx_to_thread(struct task_struct *tsk) { if (tsk->thread.regs) { @@ -406,6 +452,90 @@ void flush_spe_to_thread(struct task_struct *tsk) } #endif /* CONFIG_SPE */ +static bool fpu_support(void) +{ + if (cpu_has_feature(CPU_FTR_VSX_COMP)) { + return true; + } else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { + return true; + } else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { + return true; + } + + return false; +} + +bool kernel_fpu_enabled(void) +{ + return this_cpu_read(in_kernel_fpu); +} +EXPORT_SYMBOL(kernel_fpu_enabled); + +void kernel_fpu_begin(void) +{ + if (!fpu_support()) { + WARN_ON_ONCE(1); + return; + } + + preempt_disable(); + +#ifdef CONFIG_VSX + if (cpu_has_feature(CPU_FTR_VSX_COMP)) { + enable_kernel_vsx(); + return; + } +#endif + +#ifdef CONFIG_ALTIVEC + if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { + enable_kernel_altivec(); + return; + } +#endif + +#ifdef CONFIG_PPC_FPU + if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { + enable_kernel_fp(); + return; + } +#endif +} +EXPORT_SYMBOL_GPL(kernel_fpu_begin); + +void kernel_fpu_end(void) +{ + if (!fpu_support()) { + WARN_ON_ONCE(1); + return; + } + +#ifdef CONFIG_VSX + if (cpu_has_feature(CPU_FTR_VSX_COMP)) { + disable_kernel_vsx(); + goto done; + } +#endif + +#ifdef CONFIG_ALTIVEC + if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { + disable_kernel_altivec(); + goto done; + } +#endif + +#ifdef CONFIG_PPC_FPU + if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { + disable_kernel_fp(); + goto done; + } +#endif + +done: + preempt_enable(); +} +EXPORT_SYMBOL_GPL(kernel_fpu_end); + static unsigned long msr_all_available; static int __init init_msr_all_available(void) -- 2.25.1 _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
next prev parent reply other threads:[~2021-07-19 22:56 UTC|newest] Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-19 19:52 [RFC 0/2] Add generic FPU api similar to x86 Anson Jacob 2021-07-19 19:52 ` Anson Jacob 2021-07-19 19:52 ` Anson Jacob [this message] 2021-07-19 19:52 ` [RFC 1/2] ppc/fpu: " Anson Jacob 2021-07-20 6:04 ` Christoph Hellwig 2021-07-20 6:04 ` Christoph Hellwig 2021-07-20 19:30 ` kernel test robot 2021-07-19 19:52 ` [RFC 2/2] drm/amd/display: Use PPC FPU functions Anson Jacob 2021-07-19 19:52 ` Anson Jacob 2021-07-20 6:06 ` Christoph Hellwig 2021-07-20 6:06 ` Christoph Hellwig 2021-07-20 23:00 ` kernel test robot 2021-07-20 6:17 ` [RFC 0/2] Add generic FPU api similar to x86 Christian König 2021-07-20 6:17 ` Christian König 2022-03-02 16:00 ` Christophe Leroy
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