Re: [Minios-devel] [UNIKRAFT PATCHv4 17/43] plat/include: Define macros for Arm64 to access registers

[Wei Chen <Wei.Chen@xxxxxxx>]

Hi Julien,

> -----Original Message-----
> From: Julien Grall <julien.grall@xxxxxxx>
> Sent: 2018年7月8日 6:13
> To: Wei Chen <Wei.Chen@xxxxxxx>; minios-devel@xxxxxxxxxxxxxxxxxxxx;
> simon.kuenzer@xxxxxxxxx
> Cc: Kaly Xin <Kaly.Xin@xxxxxxx>; nd <nd@xxxxxxx>
> Subject: Re: [Minios-devel] [UNIKRAFT PATCHv4 17/43] plat/include: Define
> macros for Arm64 to access registers
> 
> Hi,
> 
> On 07/06/2018 10:03 AM, Wei Chen wrote:
> > In the progress of Arm64 system initialization, we need to access
> > the system registers to configure some CPU features, we also need
> > to access device registers to make device work. So in this patch,
> > we define macros to access device registers and system registers.
> >
> > Signed-off-by: Wei Chen <Wei.Chen@xxxxxxx>
> > ---
> >   plat/common/include/arm/arm64/cpu.h | 72 +++++++++++++++++++++++++++++
> >   plat/common/include/arm/cpu.h       | 46 ++++++++++++++++++
> >   plat/common/include/cpu.h           |  4 +-
> >   3 files changed, 121 insertions(+), 1 deletion(-)
> >   create mode 100644 plat/common/include/arm/arm64/cpu.h
> >   create mode 100644 plat/common/include/arm/cpu.h
> >
> > diff --git a/plat/common/include/arm/arm64/cpu.h
> b/plat/common/include/arm/arm64/cpu.h
> > new file mode 100644
> > index 0000000..7c79462
> > --- /dev/null
> > +++ b/plat/common/include/arm/arm64/cpu.h
> > @@ -0,0 +1,72 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause */
> > +/*
> > + * Authors: Wei Chen <wei.chen@xxxxxxx>
> > + *
> > + * Copyright (c) 2018, Arm Ltd. All rights reserved.
> > + *
> > + * Redistribution and use in source and binary forms, with or without
> > + * modification, are permitted provided that the following conditions
> > + * are met:
> > + *
> > + * 1. Redistributions of source code must retain the above copyright
> > + *    notice, this list of conditions and the following disclaimer.
> > + * 2. Redistributions in binary form must reproduce the above copyright
> > + *    notice, this list of conditions and the following disclaimer in the
> > + *    documentation and/or other materials provided with the distribution.
> > + * 3. Neither the name of the copyright holder nor the names of its
> > + *    contributors may be used to endorse or promote products derived from
> > + *    this software without specific prior written permission.
> > + *
> > + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
> IS"
> > + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
> THE
> > + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
> PURPOSE
> > + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
> BE
> > + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> > + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> > + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
> > + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
> > + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> > + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
> THE
> > + * POSSIBILITY OF SUCH DAMAGE.
> > + *
> > + * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
> > + */
> > +
> > +#include <inttypes.h>
> > +
> > +#define REG_READ8(addr)            \
> The naming is slightly confusing, you don't really now which register
> you are reading. How about renaming them to ioread. This would make
> clearer that you do io access.

That's fine with me. About this name, I have been commented in
different projects with different contents : )
Some guys said, you don't have IO instructions, why you use io as
Prefix ; )

> 
> > +   (*((const volatile uint8_t*)(addr)))
> > +#define REG_WRITE8(addr, value)    \
> > +   (*((volatile uint8_t*)(addr)) = (uint8_t)(value))
> > +
> > +#define REG_READ16(addr)            \
> > +   (*((const volatile uint16_t*)(addr)))
> > +#define REG_WRITE16(addr, value)    \
> > +   (*((volatile uint16_t*)(addr)) = (uint16_t)(value))
> > +
> > +#define REG_READ32(addr)            \
> > +   (*((const volatile uint32_t*)(addr)))
> > +#define REG_WRITE32(addr, value)    \
> > +   (*((volatile uint32_t*)(addr)) = (uint32_t)(value))
> > +
> > +#define REG_READ64(addr)            \
> > +   (*((const volatile uint64_t*)(addr)))
> > +#define REG_WRITE64(addr, value)    \
> > +   (*((volatile uint64_t*)(addr)) = (uint64_t)(value))
> 
> It would be nice to use static inline to improve a bit more the safety.

OK

> 
> > +
> > +/* Define compatibility IO macros */
> > +#define outb(addr, v)   REG_WRITE8(addr, v)
> > +#define outw(addr, v)   REG_WRITE16(addr, v)
> > +#define inb(addr)       REG_READ8(addr)
> > +
> > +/* Macros to access system registers */
> > +#define    SYSREG_READ(reg)            \
> > +({  uint64_t val;                   \
> > +   __asm__ __volatile__("mrs %0, " __STRINGIFY(reg) \
> > +                                   : "=&r" (val)); \
> > +   val;                            \
> > +})
> > +
> > +#define    SYSREG_WRITE(reg, val)      \
> > +   __asm__ __volatile__("msr " __STRINGIFY(reg) ", %0" \
> > +                                   : : "r" ((uint64_t)(val)))
> > diff --git a/plat/common/include/arm/cpu.h b/plat/common/include/arm/cpu.h
> > new file mode 100644
> > index 0000000..558945f
> > --- /dev/null
> > +++ b/plat/common/include/arm/cpu.h
> > @@ -0,0 +1,46 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause */
> > +/*
> > + * Authors: Wei Chen <wei.chen@xxxxxxx>
> > + *
> > + * Copyright (c) 2018, Arm Ltd. All rights reserved.
> > + *
> > + * Redistribution and use in source and binary forms, with or without
> > + * modification, are permitted provided that the following conditions
> > + * are met:
> > + *
> > + * 1. Redistributions of source code must retain the above copyright
> > + *    notice, this list of conditions and the following disclaimer.
> > + * 2. Redistributions in binary form must reproduce the above copyright
> > + *    notice, this list of conditions and the following disclaimer in the
> > + *    documentation and/or other materials provided with the distribution.
> > + * 3. Neither the name of the copyright holder nor the names of its
> > + *    contributors may be used to endorse or promote products derived from
> > + *    this software without specific prior written permission.
> > + *
> > + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
> IS"
> > + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
> THE
> > + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
> PURPOSE
> > + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
> BE
> > + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> > + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> > + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
> > + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
> > + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> > + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
> THE
> > + * POSSIBILITY OF SUCH DAMAGE.
> > + *
> > + * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
> > + */
> > +
> > +#ifndef __PLAT_CMN_ARM_CPU_H__
> > +#define __PLAT_CMN_ARM_CPU_H__
> > +
> > +#if defined(__ARM_32__)
> > +#include <arm/arm/cpu.h>
> 
> Why do you add the arm32 bits here? Shouldn't it be before?
> 
> A good habit is to have all the patches *at least* compiled one by one
> to help bisecting.

OK, I will remove it.

> 
> > +#elif defined(__ARM_64__)
> > +#include <arm/arm64/cpu.h>
> > +#else
> > +#error "Add cpu.h for current architecture."
> > +#endif
> > +
> > +#endif /* __PLAT_CMN_ARM_CPU_H__ */
> > diff --git a/plat/common/include/cpu.h b/plat/common/include/cpu.h
> > index 153ebf9..4f04df5 100644
> > --- a/plat/common/include/cpu.h
> > +++ b/plat/common/include/cpu.h
> > @@ -36,8 +36,10 @@
> >   #define __PLAT_CMN_CPU_H__
> >
> >   #include <uk/arch/lcpu.h>
> > -#ifdef __X86_64__
> > +#if defined(__X86_64__)
> >   #include <x86/cpu.h>
> > +#elif defined(__ARM_32__) || defined(__ARM_64__)
> > +#include <arm/cpu.h>
> >   #else
> >   #error "Add cpu.h for current architecture."
> >   #endif
> >
> 
> Cheers,
> 
> Cheers,
> --
> Julien Grall
_______________________________________________
Minios-devel mailing list
Minios-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/minios-devel