From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36405) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cGqAS-0005yu-1Q for qemu-devel@nongnu.org; Tue, 13 Dec 2016 11:43:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cGqAO-00006Y-9b for qemu-devel@nongnu.org; Tue, 13 Dec 2016 11:43:03 -0500 Received: from mail-wj0-f170.google.com ([209.85.210.170]:36140) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cGqAO-000069-2d for qemu-devel@nongnu.org; Tue, 13 Dec 2016 11:43:00 -0500 Received: by mail-wj0-f170.google.com with SMTP id tk12so105705253wjb.3 for ; Tue, 13 Dec 2016 08:42:59 -0800 (PST) References: <20161208175030.12269-1-drjones@redhat.com> <20161208175030.12269-4-drjones@redhat.com> From: Alex =?utf-8?Q?Benn=C3=A9e?= In-reply-to: <20161208175030.12269-4-drjones@redhat.com> Date: Tue, 13 Dec 2016 16:41:57 +0000 Message-ID: <8760mnu6ga.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH kvm-unit-tests v8 03/10] arm/arm64: add some delay routines List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andrew Jones Cc: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, qemu-devel@nongnu.org, qemu-arm@nongnu.org, peter.maydell@linaro.org, marc.zyngier@arm.com, andre.przywara@arm.com, eric.auger@redhat.com, pbonzini@redhat.com, christoffer.dall@linaro.org Andrew Jones writes: > Allow a thread to wait some specified amount of time. Can > specify in cycles, usecs, and msecs. > > Signed-off-by: Andrew Jones > > --- > v8: rewrote basing on new sysreg framework. Also decided delay > functions warrant their own files (delay.[ch]) > --- > arm/Makefile.common | 1 + > lib/arm/asm/delay.h | 14 ++++++++++++++ > lib/arm/asm/processor.h | 15 +++++++++++++++ > lib/arm64/asm/delay.h | 1 + > lib/arm64/asm/processor.h | 12 ++++++++++++ > lib/arm/delay.c | 29 +++++++++++++++++++++++++++++ > 6 files changed, 72 insertions(+) > create mode 100644 lib/arm/asm/delay.h > create mode 100644 lib/arm64/asm/delay.h > create mode 100644 lib/arm/delay.c > > diff --git a/arm/Makefile.common b/arm/Makefile.common > index b2c0fc8a2fdc..89fe3f69eb44 100644 > --- a/arm/Makefile.common > +++ b/arm/Makefile.common > @@ -48,6 +48,7 @@ cflatobjs += lib/arm/mmu.o > cflatobjs += lib/arm/bitops.o > cflatobjs += lib/arm/psci.o > cflatobjs += lib/arm/smp.o > +cflatobjs += lib/arm/delay.o > > libeabi = lib/arm/libeabi.a > eabiobjs = lib/arm/eabi_compat.o > diff --git a/lib/arm/asm/delay.h b/lib/arm/asm/delay.h > new file mode 100644 > index 000000000000..2436b28c77ae > --- /dev/null > +++ b/lib/arm/asm/delay.h > @@ -0,0 +1,14 @@ > +#ifndef _ASMARM_DELAY_H_ > +#define _ASMARM_DELAY_H_ > +/* > + * Copyright (C) 2016, Red Hat Inc, Andrew Jones > + * > + * This work is licensed under the terms of the GNU LGPL, version 2. > + */ > +#include > + > +extern void delay(u64 cycles); > +extern void udelay(unsigned long usecs); > +extern void mdelay(unsigned long msecs); > + > +#endif /* _ASMARM_DELAY_H_ */ > diff --git a/lib/arm/asm/processor.h b/lib/arm/asm/processor.h > index 6b0d36b87817..857bdd96a3cc 100644 > --- a/lib/arm/asm/processor.h > +++ b/lib/arm/asm/processor.h > @@ -7,6 +7,7 @@ > */ > #include > #include > +#include Hmm this fails to apply cleanly to master and doesn't build as sysreg.h isn't in my tree. What happened to it? > > enum vector { > EXCPTN_RST, > @@ -51,4 +52,18 @@ extern int mpidr_to_cpu(uint64_t mpidr); > extern void start_usr(void (*func)(void *arg), void *arg, unsigned long sp_usr); > extern bool is_user(void); > > +#define CNTVCT __ACCESS_CP15_64(1, c14) > +#define CNTFRQ __ACCESS_CP15(c14, 0, c0, 0) > + > +static inline u64 get_cntvct(void) > +{ > + isb(); > + return read_sysreg(CNTVCT); > +} > + > +static inline u32 get_cntfrq(void) > +{ > + return read_sysreg(CNTFRQ); > +} > + > #endif /* _ASMARM_PROCESSOR_H_ */ > diff --git a/lib/arm64/asm/delay.h b/lib/arm64/asm/delay.h > new file mode 100644 > index 000000000000..288e4b3fe610 > --- /dev/null > +++ b/lib/arm64/asm/delay.h > @@ -0,0 +1 @@ > +#include "../../arm/asm/delay.h" > diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h > index 48abf2c9e358..0898d89f9761 100644 > --- a/lib/arm64/asm/processor.h > +++ b/lib/arm64/asm/processor.h > @@ -20,6 +20,7 @@ > #include > #include > #include > +#include > > enum vector { > EL1T_SYNC, > @@ -83,5 +84,16 @@ extern int mpidr_to_cpu(uint64_t mpidr); > extern void start_usr(void (*func)(void *arg), void *arg, unsigned long sp_usr); > extern bool is_user(void); > > +static inline u64 get_cntvct(void) > +{ > + isb(); > + return read_sysreg(cntvct_el0); > +} > + > +static inline u32 get_cntfrq(void) > +{ > + return read_sysreg(cntfrq_el0); > +} > + > #endif /* !__ASSEMBLY__ */ > #endif /* _ASMARM64_PROCESSOR_H_ */ > diff --git a/lib/arm/delay.c b/lib/arm/delay.c > new file mode 100644 > index 000000000000..fa65e2dc9e35 > --- /dev/null > +++ b/lib/arm/delay.c > @@ -0,0 +1,29 @@ > +/* > + * Delay loops > + * > + * Copyright (C) 2016, Red Hat Inc, Andrew Jones > + * > + * This work is licensed under the terms of the GNU LGPL, version 2. > + */ > +#include > +#include > +#include > + > +void delay(u64 cycles) > +{ > + u64 start = get_cntvct(); > + > + while ((get_cntvct() - start) < cycles) > + cpu_relax(); > +} > + > +void udelay(unsigned long usec) > +{ > + delay((u64)usec * get_cntfrq() / 1000000); > +} > + > +void mdelay(unsigned long msecs) > +{ > + while (msecs--) > + udelay(1000); > +} -- Alex Bennée