Re: [dpdk-dev] [PATCH 1/8] eal: expose rte_eal_using_phys_addrs

[Jan Blunck <jblunck@infradead.org>]

On Thu, Jun 1, 2017 at 12:14 PM, Gaetan Rivet <gaetan.rivet@6wind.com> wrote:
> This function was previously private to the EAL layer.
> Other subsystems requires it, such as the PCI bus.
>
> This function is only exposed for linuxapps.
>
> In order not to force other components to include stdbool, which is
> incompatible with several NIC drivers, the return type has
> been changed from bool to int.
>
> Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>
> ---
>  lib/librte_eal/common/eal_private.h             | 11 -----
>  lib/librte_eal/linuxapp/eal/Makefile            |  2 +
>  lib/librte_eal/linuxapp/eal/eal_memory.c        |  3 +-
>  lib/librte_eal/linuxapp/eal/eal_pci.c           |  1 +
>  lib/librte_eal/linuxapp/eal/rte_eal_version.map |  1 +
>  lib/librte_eal/linuxapp/eal/rte_memory_linux.h  | 64 +++++++++++++++++++++++++
>  6 files changed, 70 insertions(+), 12 deletions(-)
>  create mode 100644 lib/librte_eal/linuxapp/eal/rte_memory_linux.h
>
> diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h
> index 6d2206a..b7e4cc6 100644
> --- a/lib/librte_eal/common/eal_private.h
> +++ b/lib/librte_eal/common/eal_private.h
> @@ -327,17 +327,6 @@ int rte_eal_hugepage_init(void);
>   */
>  int rte_eal_hugepage_attach(void);
>
> -/**
> - * Returns true if the system is able to obtain
> - * physical addresses. Return false if using DMA
> - * addresses through an IOMMU.
> - *
> - * Drivers based on uio will not load unless physical
> - * addresses are obtainable. It is only possible to get
> - * physical addresses when running as a privileged user.
> - */
> -bool rte_eal_using_phys_addrs(void);
> -
>  /*
>   * Validate a bus name.
>   *
> diff --git a/lib/librte_eal/linuxapp/eal/Makefile b/lib/librte_eal/linuxapp/eal/Makefile
> index 640afd0..530e286 100644
> --- a/lib/librte_eal/linuxapp/eal/Makefile
> +++ b/lib/librte_eal/linuxapp/eal/Makefile
> @@ -131,4 +131,6 @@ INC := rte_interrupts.h rte_kni_common.h rte_dom0_common.h
>  SYMLINK-$(CONFIG_RTE_EXEC_ENV_LINUXAPP)-include/exec-env := \
>         $(addprefix include/exec-env/,$(INC))
>
> +SYMLINK-$(CONFIG_RTE_EXEC_ENV_LINUXAPP)-include += rte_memory_linux.h
> +
>  include $(RTE_SDK)/mk/rte.lib.mk
> diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
> index ebe0683..072bfe4 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_memory.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
> @@ -99,6 +99,7 @@
>  #include "eal_internal_cfg.h"
>  #include "eal_filesystem.h"
>  #include "eal_hugepages.h"
> +#include "rte_memory_linux.h"
>
>  #define PFN_MASK_SIZE  8
>
> @@ -1472,7 +1473,7 @@ rte_eal_hugepage_attach(void)
>         return -1;
>  }
>
> -bool
> +int
>  rte_eal_using_phys_addrs(void)
>  {
>         return phys_addrs_available;
> diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
> index 595622b..9d5b051 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_pci.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
> @@ -45,6 +45,7 @@
>  #include "eal_filesystem.h"
>  #include "eal_private.h"
>  #include "eal_pci_init.h"
> +#include "rte_memory_linux.h"
>
>  /**
>   * @file
> diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> index a5127d6..8916520 100644
> --- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> +++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> @@ -207,5 +207,6 @@ DPDK_17.08 {
>
>         rte_bus_from_name;
>         rte_bus_from_dev;
> +       rte_eal_using_phys_addrs;

Is this only for the UIO mapping? Would it be better to let UIO skip
(and warn?) over RTE_BAD_PHYS_ADDR mappings? That way we don't need
this export and its probably more resilient to bad mappings.

Thoughts? Olivier?

>
>  } DPDK_17.05;
> diff --git a/lib/librte_eal/linuxapp/eal/rte_memory_linux.h b/lib/librte_eal/linuxapp/eal/rte_memory_linux.h
> new file mode 100644
> index 0000000..0400711
> --- /dev/null
> +++ b/lib/librte_eal/linuxapp/eal/rte_memory_linux.h
> @@ -0,0 +1,64 @@
> +/*-
> + *   BSD LICENSE
> + *
> + *   Copyright(c) 2017 6WIND S.A. All rights reserved.
> + *   All rights reserved.
> + *
> + *   Redistribution and use in source and binary forms, with or without
> + *   modification, are permitted provided that the following conditions
> + *   are met:
> + *
> + *     * Redistributions of source code must retain the above copyright
> + *       notice, this list of conditions and the following disclaimer.
> + *     * 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.
> + *     * Neither the name of 6WIND 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
> + *   OWNER 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.
> + */
> +
> +#ifndef _RTE_MEMORY_LINUX_H_
> +#define _RTE_MEMORY_LINUX_H_
> +
> +/**
> + * @file
> + *
> + * Memory-related Linux-specific RTE API.
> + */
> +
> +#include <rte_memory.h>
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +/**
> + * Drivers based on uio will not load unless physical
> + * addresses are obtainable. It is only possible to get
> + * physical addresses when running as a privileged user.
> + *
> + * @return
> + *   1 if the system is able to obtain physical addresses.
> + *   0 if using DMA addresses through an IOMMU.
> + */
> +int rte_eal_using_phys_addrs(void);
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +
> +#endif /* _RTE_MEMORY_LINUX_H_ */
> --
> 2.1.4
>