Re: [dpdk-dev] [PATCH 09/27] event/dlb: add inline functions used in multiple files

[Bruce Richardson <bruce.richardson@intel.com>]

On Fri, Jun 26, 2020 at 11:37:33PM -0500, Tim McDaniel wrote:
> From: "McDaniel, Timothy" <timothy.mcdaniel@intel.com>
> 
> Signed-off-by: McDaniel, Timothy <timothy.mcdaniel@intel.com>
> ---
>  drivers/event/dlb/dlb_inline_fns.h |   80 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 80 insertions(+)
>  create mode 100644 drivers/event/dlb/dlb_inline_fns.h
> 
> diff --git a/drivers/event/dlb/dlb_inline_fns.h b/drivers/event/dlb/dlb_inline_fns.h
> new file mode 100644
> index 0000000..86f85aa
> --- /dev/null
> +++ b/drivers/event/dlb/dlb_inline_fns.h
> @@ -0,0 +1,80 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2016-2020 Intel Corporation
> + */
> +
> +#include "rte_memcpy.h"
> +#include "rte_io.h"
> +
> +/* Inline functions required in more than one source file.
> + */
> +
> +static inline struct dlb_eventdev *
> +dlb_pmd_priv(const struct rte_eventdev *eventdev)
> +{
> +	return eventdev->data->dev_private;
> +}
> +
> +static inline void
> +dlb_umonitor(volatile void *addr)
> +{
> +	asm volatile(".byte 0xf3, 0x0f, 0xae, 0xf7\t\n"
> +			:
> +			: "D" (addr));
> +}
> +
> +static inline void
> +dlb_umwait(int state, uint64_t timeout)
> +{
> +	uint32_t eax = timeout & UINT32_MAX;
> +	uint32_t edx = timeout >> 32;
> +
> +	asm volatile(".byte 0xf2, 0x0f, 0xae, 0xf7\t\n"
> +			:
> +			: "D" (state),  "a" (eax), "d" (edx));
> +}
> +
> +static inline void
> +dlb_movntdq(void *qe4, void *pp_addr)
> +{
> +	/* Move entire 64B cache line of QEs, 128 bits (16B) at a time. */
> +	long long *_qe  = (long long *)qe4;
> +	__v2di src_data0 = (__v2di){_qe[0], _qe[1]};
> +	__v2di src_data1 = (__v2di){_qe[2], _qe[3]};
> +	__v2di src_data2 = (__v2di){_qe[4], _qe[5]};
> +	__v2di src_data3 = (__v2di){_qe[6], _qe[7]};
> +
> +	__builtin_ia32_movntdq((__v2di *)pp_addr + 0, (__v2di)src_data0);
> +	rte_wmb();
> +	__builtin_ia32_movntdq((__v2di *)pp_addr + 1, (__v2di)src_data1);
> +	rte_wmb();
> +	__builtin_ia32_movntdq((__v2di *)pp_addr + 2, (__v2di)src_data2);
> +	rte_wmb();
> +	__builtin_ia32_movntdq((__v2di *)pp_addr + 3, (__v2di)src_data3);
> +	rte_wmb();
> +}
> +
> +static inline void
> +dlb_movntdq_single(void *qe4, void *pp_addr)
> +{
> +	long long *_qe  = (long long *)qe4;
> +	__v2di src_data0 = (__v2di){_qe[0], _qe[1]};
> +
> +	__builtin_ia32_movntdq((__v2di *)pp_addr, (__v2di)src_data0);
> +}
> +
> +static inline void
> +dlb_cldemote(void *addr)
> +{
> +	/* Load addr into RSI, then demote the cache line of the address
> +	 * contained in that register.
> +	 */
> +	asm volatile(".byte 0x0f, 0x1c, 0x06" :: "S" (addr));
> +}
> +
> +static inline void
> +dlb_movdir64b(void *qe4, void *pp_addr)
> +{
> +	asm volatile(".byte 0x66, 0x0f, 0x38, 0xf8, 0x02"
> +		     :
> +		     : "a" (pp_addr), "d" (qe4));
> +}
> -- 

Although these are mostly x86-specific, a number of these functions may be
needed in other places in DPDK also, so they should perhaps be put in a
common location.

Also, for the use of these, can you try and align the parameter names and
order as far as possible with those of the equivalent x86 intrinsics
documented at
https://software.intel.com/sites/landingpage/IntrinsicsGuide/. This will
make it easier in the future to switch to use the proper intrinsics rather
than our own versions. For example, _movdir64b intrinsic has parameters
"void *dst, const void *src", which is reversed to what you have here.

Thanks,
/Bruce