Re: [PATCH 4/5] libxc: minios: Introduce abstraction for files[]

["Jürgen Groß" <jgross@suse.com>]

On 02/26/2015 12:56 PM, Wei Liu wrote:
> From: Ian Jackson <ian.jackson@eu.citrix.com>
>
> We are going to want to reuse this code for NetBSD rump kernels, where
> there is no gntmap device and we just want to call the MiniOS gntmap
> code directly.
>
> As part of this we want to abstract away the use of files[] inside the
> actual functions.  Do this with a #define whose definition we are
> going to make conditional in just a moment.
>
> No functional change in this patch.
>
> Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
> ---
>   tools/libxc/xc_minios_privcmd.c | 15 +++++++--------
>   1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/tools/libxc/xc_minios_privcmd.c b/tools/libxc/xc_minios_privcmd.c
> index 7766b86..27d9076 100644
> --- a/tools/libxc/xc_minios_privcmd.c
> +++ b/tools/libxc/xc_minios_privcmd.c
> @@ -208,12 +208,14 @@ struct xc_osdep_ops xc_privcmd_ops = {
>       },
>   };
>
> +#define GNTMAP(h) (files[(int)(h)].gntmap)
> +
>   static xc_osdep_handle minios_gnttab_open(xc_gnttab *xcg)
>   {
>       int fd = alloc_fd(FTYPE_GNTMAP);
>       if ( fd == -1 )
>           return XC_OSDEP_OPEN_ERROR;
> -    gntmap_init(&files[fd].gntmap);
> +    gntmap_init(&GNTMAP(h));

GNTMAP(fd)?

Same multiple times below.


Juergen

>       return (xc_osdep_handle)fd;
>   }
>
> @@ -225,7 +227,7 @@ static int minios_gnttab_close(xc_gnttab *xcg, xc_osdep_handle h)
>
>   void minios_gnttab_close_fd(int fd)
>   {
> -    gntmap_fini(&files[fd].gntmap);
> +    gntmap_fini(&GNTMAP(h));
>       files[fd].type = FTYPE_NONE;
>   }
>
> @@ -235,7 +237,6 @@ static void *minios_gnttab_grant_map(xc_gnttab *xcg, xc_osdep_handle h,
>                                        uint32_t notify_offset,
>                                        evtchn_port_t notify_port)
>   {
> -    int fd = (int)h;
>       int stride = 1;
>       if (flags & XC_GRANT_MAP_SINGLE_DOMAIN)
>           stride = 0;
> @@ -243,7 +244,7 @@ static void *minios_gnttab_grant_map(xc_gnttab *xcg, xc_osdep_handle h,
>           errno = ENOSYS;
>           return NULL;
>       }
> -    return gntmap_map_grant_refs(&files[fd].gntmap,
> +    return gntmap_map_grant_refs(&GNTMAP(h),
>                                    count, domids, stride,
>                                    refs, prot & PROT_WRITE);
>   }
> @@ -252,9 +253,8 @@ static int minios_gnttab_munmap(xc_gnttab *xcg, xc_osdep_handle h,
>                                   void *start_address,
>                                   uint32_t count)
>   {
> -    int fd = (int)h;
>       int ret;
> -    ret = gntmap_munmap(&files[fd].gntmap,
> +    ret = gntmap_munmap(&GNTMAP(h),
>                           (unsigned long) start_address,
>                           count);
>       if (ret < 0) {
> @@ -267,9 +267,8 @@ static int minios_gnttab_munmap(xc_gnttab *xcg, xc_osdep_handle h,
>   static int minios_gnttab_set_max_grants(xc_gnttab *xcg, xc_osdep_handle h,
>                                uint32_t count)
>   {
> -    int fd = (int)h;
>       int ret;
> -    ret = gntmap_set_max_grants(&files[fd].gntmap,
> +    ret = gntmap_set_max_grants(&GNTMAP(h),
>                                   count);
>       if (ret < 0) {
>           errno = -ret;
>