From: Dave Martin <Dave.Martin@arm.com> To: Mark Rutland <mark.rutland@arm.com> Cc: marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, linux@dominikbrodowski.net, james.morse@arm.com, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 06/18] arm64: move sve_user_{enable, disable} to <asm/fpsimd.h> Date: Tue, 15 May 2018 13:19:26 +0100 [thread overview] Message-ID: <20180515121921.GN7753@e103592.cambridge.arm.com> (raw) In-Reply-To: <20180515103936.v5ytofdq3qqtsomn@lakrids.cambridge.arm.com> On Tue, May 15, 2018 at 11:39:36AM +0100, Mark Rutland wrote: > On Mon, May 14, 2018 at 12:06:50PM +0100, Dave Martin wrote: > > On Mon, May 14, 2018 at 10:46:28AM +0100, Mark Rutland wrote: > > > In subsequent patches, we'll want to make use of sve_user_enable() and > > > sve_user_disable() outside of kernel/fpsimd.c. Let's move these to > > > <asm/fpsimd.h> where we can make use of them. > > > > > > To avoid ifdeffery in sequences like: > > > > > > if (system_supports_sve() && some_condition > > > sve_user_disable(); > > > > > > ... empty stubs are provided when support for SVE is not enabled. > > > > > > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > > > Cc: Catalin Marinas <catalin.marinas@arm.com> > > > Cc: Dave Martin <dave.martin@arm.com> > > > Cc: Will Deacon <will.deacon@arm.com> > > > --- > > > arch/arm64/include/asm/fpsimd.h | 17 ++++++++++++++++- > > > arch/arm64/kernel/fpsimd.c | 11 ----------- > > > 2 files changed, 16 insertions(+), 12 deletions(-) > > > > > > diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h > > > index aa7162ae93e3..7377d7593c06 100644 > > > --- a/arch/arm64/include/asm/fpsimd.h > > > +++ b/arch/arm64/include/asm/fpsimd.h > > > @@ -16,11 +16,13 @@ > > > #ifndef __ASM_FP_H > > > #define __ASM_FP_H > > > > > > -#include <asm/ptrace.h> > > > #include <asm/errno.h> > > > +#include <asm/ptrace.h> > > > +#include <asm/sysreg.h> > > > > > > #ifndef __ASSEMBLY__ > > > > > > +#include <linux/build_bug.h> > > > #include <linux/cache.h> > > > #include <linux/init.h> > > > #include <linux/stddef.h> > > > @@ -81,6 +83,16 @@ extern int sve_set_vector_length(struct task_struct *task, > > > extern int sve_set_current_vl(unsigned long arg); > > > extern int sve_get_current_vl(void); > > > > > > +static inline void sve_user_disable(void) > > > +{ > > > + sysreg_clear_set(cpacr_el1, CPACR_EL1_ZEN_EL0EN, 0); > > > +} > > > + > > > +static inline void sve_user_enable(void) > > > +{ > > > + sysreg_clear_set(cpacr_el1, 0, CPACR_EL1_ZEN_EL0EN); > > > +} > > > + > > > /* > > > * Probing and setup functions. > > > * Calls to these functions must be serialised with one another. > > > @@ -107,6 +119,9 @@ static inline int sve_get_current_vl(void) > > > return -EINVAL; > > > } > > > > > > +static inline void sve_user_disable(void) { } > > > +static inline void sve_user_enable(void) { } > > > + > > > > Alternatively, just move the full definitions outside the #ifdef > > CONFIG_ARM64_SVE. > > Can do, though I was trying to keep the exsting pattern with empty > inlines for the !CONFIG_ARM64_SVE case. There isn't really a pattern. I tried to avoid dummy versions where there's no real reason to have them. I don't _think_ they're really needed here, unless I missed something. Did you get build failures without them? > > All calls to these should be shadowed by an if > > (system_supports_sve()) in any case, and setting/clearing ZEN_EL0EN > > in the CPACR_EL1 ought to be harmless now that the meaning of these > > bits architecturally committed. > > > > Ideally we would have a BUG_ON(!system_supports_sve()) in those > > functions, but we won't won't to pay the cost in a production kernel. > > Earlier I'd put BUILD_BUG() in the body for the !CONFIG_ARM64_SVE case, > to catch that kind of thing -- I could restore that. IIUC: if (0) { BUILD_BUG_ON(1); } can still fire, in which case it's futile checking for CONFIG_ARM64_SVE in most of the SVE support code. Anyway, CONFIG_ARM64_SVE doesn't capture the whole condition. > > > > static inline void sve_init_vq_map(void) { } > > > static inline void sve_update_vq_map(void) { } > > > static inline int sve_verify_vq_map(void) { return 0; } > > > diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c > > > index 088940387a4d..79a81c7d85c6 100644 > > > --- a/arch/arm64/kernel/fpsimd.c > > > +++ b/arch/arm64/kernel/fpsimd.c > > > @@ -159,7 +159,6 @@ static void sve_free(struct task_struct *task) > > > __sve_free(task); > > > } > > > > > > - > > > > Hmmm, Ack. Check for conflicts with the KVM FPSIMD rework [1] (though > > trivial). > > I'll assume that Ack stands regardless. :) Actually, I was just commenting on the deleted blank line... not that there is any massive issue with this patch, though. Cheers ---Dave
WARNING: multiple messages have this Message-ID (diff)
From: Dave.Martin@arm.com (Dave Martin) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 06/18] arm64: move sve_user_{enable, disable} to <asm/fpsimd.h> Date: Tue, 15 May 2018 13:19:26 +0100 [thread overview] Message-ID: <20180515121921.GN7753@e103592.cambridge.arm.com> (raw) In-Reply-To: <20180515103936.v5ytofdq3qqtsomn@lakrids.cambridge.arm.com> On Tue, May 15, 2018 at 11:39:36AM +0100, Mark Rutland wrote: > On Mon, May 14, 2018 at 12:06:50PM +0100, Dave Martin wrote: > > On Mon, May 14, 2018 at 10:46:28AM +0100, Mark Rutland wrote: > > > In subsequent patches, we'll want to make use of sve_user_enable() and > > > sve_user_disable() outside of kernel/fpsimd.c. Let's move these to > > > <asm/fpsimd.h> where we can make use of them. > > > > > > To avoid ifdeffery in sequences like: > > > > > > if (system_supports_sve() && some_condition > > > sve_user_disable(); > > > > > > ... empty stubs are provided when support for SVE is not enabled. > > > > > > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > > > Cc: Catalin Marinas <catalin.marinas@arm.com> > > > Cc: Dave Martin <dave.martin@arm.com> > > > Cc: Will Deacon <will.deacon@arm.com> > > > --- > > > arch/arm64/include/asm/fpsimd.h | 17 ++++++++++++++++- > > > arch/arm64/kernel/fpsimd.c | 11 ----------- > > > 2 files changed, 16 insertions(+), 12 deletions(-) > > > > > > diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h > > > index aa7162ae93e3..7377d7593c06 100644 > > > --- a/arch/arm64/include/asm/fpsimd.h > > > +++ b/arch/arm64/include/asm/fpsimd.h > > > @@ -16,11 +16,13 @@ > > > #ifndef __ASM_FP_H > > > #define __ASM_FP_H > > > > > > -#include <asm/ptrace.h> > > > #include <asm/errno.h> > > > +#include <asm/ptrace.h> > > > +#include <asm/sysreg.h> > > > > > > #ifndef __ASSEMBLY__ > > > > > > +#include <linux/build_bug.h> > > > #include <linux/cache.h> > > > #include <linux/init.h> > > > #include <linux/stddef.h> > > > @@ -81,6 +83,16 @@ extern int sve_set_vector_length(struct task_struct *task, > > > extern int sve_set_current_vl(unsigned long arg); > > > extern int sve_get_current_vl(void); > > > > > > +static inline void sve_user_disable(void) > > > +{ > > > + sysreg_clear_set(cpacr_el1, CPACR_EL1_ZEN_EL0EN, 0); > > > +} > > > + > > > +static inline void sve_user_enable(void) > > > +{ > > > + sysreg_clear_set(cpacr_el1, 0, CPACR_EL1_ZEN_EL0EN); > > > +} > > > + > > > /* > > > * Probing and setup functions. > > > * Calls to these functions must be serialised with one another. > > > @@ -107,6 +119,9 @@ static inline int sve_get_current_vl(void) > > > return -EINVAL; > > > } > > > > > > +static inline void sve_user_disable(void) { } > > > +static inline void sve_user_enable(void) { } > > > + > > > > Alternatively, just move the full definitions outside the #ifdef > > CONFIG_ARM64_SVE. > > Can do, though I was trying to keep the exsting pattern with empty > inlines for the !CONFIG_ARM64_SVE case. There isn't really a pattern. I tried to avoid dummy versions where there's no real reason to have them. I don't _think_ they're really needed here, unless I missed something. Did you get build failures without them? > > All calls to these should be shadowed by an if > > (system_supports_sve()) in any case, and setting/clearing ZEN_EL0EN > > in the CPACR_EL1 ought to be harmless now that the meaning of these > > bits architecturally committed. > > > > Ideally we would have a BUG_ON(!system_supports_sve()) in those > > functions, but we won't won't to pay the cost in a production kernel. > > Earlier I'd put BUILD_BUG() in the body for the !CONFIG_ARM64_SVE case, > to catch that kind of thing -- I could restore that. IIUC: if (0) { BUILD_BUG_ON(1); } can still fire, in which case it's futile checking for CONFIG_ARM64_SVE in most of the SVE support code. Anyway, CONFIG_ARM64_SVE doesn't capture the whole condition. > > > > static inline void sve_init_vq_map(void) { } > > > static inline void sve_update_vq_map(void) { } > > > static inline int sve_verify_vq_map(void) { return 0; } > > > diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c > > > index 088940387a4d..79a81c7d85c6 100644 > > > --- a/arch/arm64/kernel/fpsimd.c > > > +++ b/arch/arm64/kernel/fpsimd.c > > > @@ -159,7 +159,6 @@ static void sve_free(struct task_struct *task) > > > __sve_free(task); > > > } > > > > > > - > > > > Hmmm, Ack. Check for conflicts with the KVM FPSIMD rework [1] (though > > trivial). > > I'll assume that Ack stands regardless. :) Actually, I was just commenting on the deleted blank line... not that there is any massive issue with this patch, though. Cheers ---Dave
next prev parent reply other threads:[~2018-05-15 12:19 UTC|newest] Thread overview: 126+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-05-14 9:46 [PATCH 00/18] arm64: invoke syscalls with pt_regs Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 9:46 ` [PATCH 01/18] arm64: consistently use unsigned long for thread flags Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 9:57 ` Dave Martin 2018-05-14 9:57 ` Dave Martin 2018-05-14 9:46 ` [PATCH 02/18] arm64: move SCTLR_EL{1,2} assertions to <asm/sysreg.h> Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 10:00 ` Dave Martin 2018-05-14 10:00 ` Dave Martin 2018-05-14 10:08 ` Mark Rutland 2018-05-14 10:08 ` Mark Rutland 2018-05-14 11:20 ` Dave Martin 2018-05-14 11:20 ` Dave Martin 2018-05-14 11:56 ` Robin Murphy 2018-05-14 11:56 ` Robin Murphy 2018-05-14 12:06 ` Mark Rutland 2018-05-14 12:06 ` Mark Rutland 2018-05-14 12:41 ` Dave Martin 2018-05-14 12:41 ` Dave Martin 2018-05-14 13:10 ` Mark Rutland 2018-05-14 13:10 ` Mark Rutland 2018-05-14 9:46 ` [PATCH 03/18] arm64: introduce sysreg_clear_set() Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 10:04 ` Dave Martin 2018-05-14 10:04 ` Dave Martin 2018-05-14 9:46 ` [PATCH 04/18] arm64: kill config_sctlr_el1() Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 10:05 ` Dave Martin 2018-05-14 10:05 ` Dave Martin 2018-05-14 9:46 ` [PATCH 05/18] arm64: kill change_cpacr() Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 10:06 ` Dave Martin 2018-05-14 10:06 ` Dave Martin 2018-05-14 9:46 ` [PATCH 06/18] arm64: move sve_user_{enable,disable} to <asm/fpsimd.h> Mark Rutland 2018-05-14 9:46 ` [PATCH 06/18] arm64: move sve_user_{enable, disable} " Mark Rutland 2018-05-14 11:06 ` Dave Martin 2018-05-14 11:06 ` Dave Martin 2018-05-15 10:39 ` Mark Rutland 2018-05-15 10:39 ` Mark Rutland 2018-05-15 12:19 ` Dave Martin [this message] 2018-05-15 12:19 ` Dave Martin 2018-05-15 16:33 ` Mark Rutland 2018-05-15 16:33 ` Mark Rutland 2018-05-16 9:01 ` Dave Martin 2018-05-16 9:01 ` Dave Martin 2018-06-01 10:29 ` Mark Rutland 2018-06-01 10:29 ` Mark Rutland 2018-06-01 10:42 ` Dave Martin 2018-06-01 10:42 ` Dave Martin 2018-05-14 9:46 ` [PATCH 07/18] arm64: remove sigreturn wrappers Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 11:07 ` Dave Martin 2018-05-14 11:07 ` Dave Martin 2018-05-14 9:46 ` [PATCH 08/18] arm64: convert raw syscall invocation to C Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 11:07 ` Dave Martin 2018-05-14 11:07 ` Dave Martin 2018-05-14 11:41 ` Mark Rutland 2018-05-14 11:41 ` Mark Rutland 2018-05-14 12:53 ` Dave Martin 2018-05-14 12:53 ` Dave Martin 2018-05-14 20:24 ` Dominik Brodowski 2018-05-14 20:24 ` Dominik Brodowski 2018-05-15 8:22 ` Mark Rutland 2018-05-15 8:22 ` Mark Rutland 2018-05-15 10:01 ` Dominik Brodowski 2018-05-15 10:01 ` Dominik Brodowski 2018-05-15 10:13 ` Mark Rutland 2018-05-15 10:13 ` Mark Rutland 2018-05-14 18:00 ` Dominik Brodowski 2018-05-14 18:00 ` Dominik Brodowski 2018-05-15 8:18 ` Mark Rutland 2018-05-15 8:18 ` Mark Rutland 2018-05-14 9:46 ` [PATCH 09/18] arm64: convert syscall trace logic " Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 9:46 ` [PATCH 10/18] arm64: convert native/compat syscall entry " Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 11:07 ` Dave Martin 2018-05-14 11:07 ` Dave Martin 2018-05-14 11:58 ` Mark Rutland 2018-05-14 11:58 ` Mark Rutland 2018-05-14 14:43 ` Dave Martin 2018-05-14 14:43 ` Dave Martin 2018-05-14 15:01 ` Mark Rutland 2018-05-14 15:01 ` Mark Rutland 2018-05-14 9:46 ` [PATCH 11/18] arm64: zero GPRs upon entry from EL0 Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 11:07 ` Dave Martin 2018-05-14 11:07 ` Dave Martin 2018-05-14 9:46 ` [PATCH 12/18] kernel: add ksys_personality() Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 11:08 ` Dave Martin 2018-05-14 11:08 ` Dave Martin 2018-05-14 12:07 ` Christoph Hellwig 2018-05-14 12:07 ` Christoph Hellwig 2018-05-15 9:56 ` Mark Rutland 2018-05-15 9:56 ` Mark Rutland 2018-05-14 9:46 ` [PATCH 13/18] kernel: add kcompat_sys_{f,}statfs64() Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 17:14 ` Mark Rutland 2018-05-14 17:14 ` Mark Rutland 2018-05-14 20:34 ` Dominik Brodowski 2018-05-14 20:34 ` Dominik Brodowski 2018-05-15 9:53 ` Mark Rutland 2018-05-15 9:53 ` Mark Rutland 2018-05-15 9:58 ` Dominik Brodowski 2018-05-15 9:58 ` Dominik Brodowski 2018-05-14 9:46 ` [PATCH 14/18] arm64: remove in-kernel call to sys_personality() Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 9:46 ` [PATCH 15/18] arm64: use {COMPAT,}SYSCALL_DEFINE0 for sigreturn Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 9:46 ` [PATCH 16/18] arm64: use SYSCALL_DEFINE6() for mmap Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 9:46 ` [PATCH 17/18] arm64: convert compat wrappers to C Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 12:10 ` Christoph Hellwig 2018-05-14 12:10 ` Christoph Hellwig 2018-05-14 12:43 ` Mark Rutland 2018-05-14 12:43 ` Mark Rutland 2018-05-14 9:46 ` [PATCH 18/18] arm64: implement syscall wrappers Mark Rutland 2018-05-14 9:46 ` Mark Rutland 2018-05-14 20:57 ` Dominik Brodowski 2018-05-14 20:57 ` Dominik Brodowski 2018-05-15 8:37 ` Mark Rutland 2018-05-15 8:37 ` Mark Rutland
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