[PATCH 1/2] include: Add support for byteorder/endianness conversion

[Rahul Pathak]

Hi Sergey,

Using __builtins_bswapX causes weird issues on gcc,
due to reasons unknown the functions in libfdt_env.h
like below emit the library call to __bswapdi2
which causes errors.

static inline fdt32_t cpu_to_fdt32(uint32_t x)
{
return (FDT_FORCE fdt32_t)cpu_to_be32(x);
}

Errors -
fdt_reset_gpio.c:135: undefined reference to `__bswapsi2'
/fdt_reset_thead.c:77: undefined reference to `__bswapsi2'

Clang works perfectly

Did you face such issues?

Thanks
Rahul


On Tue, Jan 31, 2023 at 1:41 PM Sergey Matyukevich <geomatsi at gmail.com> wrote:
>
> On Sat, Jan 28, 2023 at 01:16:16PM +0530, Rahul Pathak wrote:
> > Define macros for general byteorder conversion
> > Define functions for endianness conversion
> > using general byteorder conversion macros
> >
> > Signed-off-by: Rahul Pathak <rpathak at ventanamicro.com>
> > ---
> >  include/sbi/sbi_byteorder.h | 57 +++++++++++++++++++++++++++++++++++++
> >  1 file changed, 57 insertions(+)
> >  create mode 100644 include/sbi/sbi_byteorder.h
>
> Reviewed-by: Sergey Matyukevich <sergey.matyukevich at syntacore.com>
>
> By the way, is there any advantage of using custom macros instead of
> compiler builtins ? E.g. see my patch loosely based on FreeBSD code:
> http://lists.infradead.org/pipermail/opensbi/2022-December/003766.html
>
> Regards,
> Sergey
>
>
> > diff --git a/include/sbi/sbi_byteorder.h b/include/sbi/sbi_byteorder.h
> > new file mode 100644
> > index 000000000000..680710fe6d91
> > --- /dev/null
> > +++ b/include/sbi/sbi_byteorder.h
> > @@ -0,0 +1,57 @@
> > +/*
> > + * SPDX-License-Identifier: BSD-2-Clause
> > + *
> > + * Copyright (c) 2023 Ventana Micro Systems Inc.
> > + */
> > +
> > +#ifndef __SBI_BYTEORDER_H__
> > +#define __SBI_BYTEORDER_H__
> > +
> > +#include <sbi/sbi_types.h>
> > +
> > +#define EXTRACT_BYTE(x, n)   ((unsigned long long)((uint8_t *)&x)[n])
> > +
> > +#define BSWAP16(x)   ((EXTRACT_BYTE(x, 0) << 8) | EXTRACT_BYTE(x, 1))
> > +#define BSWAP32(x)   ((EXTRACT_BYTE(x, 0) << 24) | (EXTRACT_BYTE(x, 1) << 16) | \
> > +                      (EXTRACT_BYTE(x, 2) << 8) | EXTRACT_BYTE(x, 3))
> > +#define BSWAP64(x)   ((EXTRACT_BYTE(x, 0) << 56) | (EXTRACT_BYTE(x, 1) << 48) | \
> > +                      (EXTRACT_BYTE(x, 2) << 40) | (EXTRACT_BYTE(x, 3) << 32) | \
> > +                      (EXTRACT_BYTE(x, 4) << 24) | (EXTRACT_BYTE(x, 5) << 16) | \
> > +                      (EXTRACT_BYTE(x, 6) << 8) | EXTRACT_BYTE(x, 7))
> > +
> > +
> > +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__  /* CPU(little-endian) */
> > +#define cpu_to_be16(x)               ((uint16_t)BSWAP16(x))
> > +#define cpu_to_be32(x)               ((uint32_t)BSWAP32(x))
> > +#define cpu_to_be64(x)               ((uint64_t)BSWAP64(x))
> > +
> > +#define be16_to_cpu(x)               ((uint16_t)BSWAP16(x))
> > +#define be32_to_cpu(x)               ((uint32_t)BSWAP32(x))
> > +#define be64_to_cpu(x)               ((uint64_t)BSWAP64(x))
> > +
> > +#define cpu_to_le16(x)               ((uint16_t)(x))
> > +#define cpu_to_le32(x)               ((uint32_t)(x))
> > +#define cpu_to_le64(x)               ((uint64_t)(x))
> > +
> > +#define le16_to_cpu(x)               ((uint16_t)(x))
> > +#define le32_to_cpu(x)               ((uint32_t)(x))
> > +#define le64_to_cpu(x)               ((uint64_t)(x))
> > +#else /* CPU(big-endian) */
> > +#define cpu_to_be16(x)               ((uint16_t)(x))
> > +#define cpu_to_be32(x)               ((uint32_t)(x))
> > +#define cpu_to_be64(x)               ((uint64_t)(x))
> > +
> > +#define be16_to_cpu(x)               ((uint16_t)(x))
> > +#define be32_to_cpu(x)               ((uint32_t)(x))
> > +#define be64_to_cpu(x)               ((uint64_t)(x))
> > +
> > +#define cpu_to_le16(x)               ((uint16_t)BSWAP16(x))
> > +#define cpu_to_le32(x)               ((uint32_t)BSWAP32(x))
> > +#define cpu_to_le64(x)               ((uint64_t)BSWAP64(x))
> > +
> > +#define le16_to_cpu(x)               ((uint16_t)BSWAP16(x))
> > +#define le32_to_cpu(x)               ((uint32_t)BSWAP32(x))
> > +#define le64_to_cpu(x)               ((uint64_t)BSWAP64(x))
> > +#endif
> > +
> > +#endif /* __SBI_BYTEORDER_H__ */
> > --
> > 2.34.1
> >
> >
> > --
> > opensbi mailing list
> > opensbi at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/opensbi



-- 

Thanks
Rahul Pathak