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| author | Annie Li <annie.li@oracle.com> | 2011-11-22 09:58:47 +0800 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-11-22 09:24:00 -0500 |
| commit | b1e495b2fae578b1bd3ab1906cb15aac43f96fee (patch) | |
| tree | 5e0495f8a27465b0f43981518060d5301b8b9845 /drivers/xen | |
| parent | 0f9f5a9588468cddeccc9146b86798492c7cd4f5 (diff) | |
| download | linux-b1e495b2fae578b1bd3ab1906cb15aac43f96fee.tar.bz2 | |
xen/granttable: Refactor some code
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Annie Li <annie.li@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/grant-table.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 18355a53763f..0518d0404942 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -257,15 +257,17 @@ EXPORT_SYMBOL_GPL(gnttab_query_foreign_access); static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) { u16 flags, nflags; + u16 *pflags; - nflags = gnttab_shared.v1[ref].flags; + pflags = &gnttab_shared.v1[ref].flags; + nflags = *pflags; do { flags = nflags; if (flags & (GTF_reading|GTF_writing)) { printk(KERN_ALERT "WARNING: g.e. still in use!\n"); return 0; } - } while ((nflags = sync_cmpxchg(&gnttab_shared.v1[ref].flags, flags, 0)) != flags); + } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags); return 1; } @@ -316,20 +318,23 @@ static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) { unsigned long frame; u16 flags; + u16 *pflags; + + pflags = &gnttab_shared.v1[ref].flags; /* * If a transfer is not even yet started, try to reclaim the grant * reference and return failure (== 0). */ - while (!((flags = gnttab_shared.v1[ref].flags) & GTF_transfer_committed)) { - if (sync_cmpxchg(&gnttab_shared.v1[ref].flags, flags, 0) == flags) + while (!((flags = *pflags) & GTF_transfer_committed)) { + if (sync_cmpxchg(pflags, flags, 0) == flags) return 0; cpu_relax(); } /* If a transfer is in progress then wait until it is completed. */ while (!(flags & GTF_transfer_completed)) { - flags = gnttab_shared.v1[ref].flags; + flags = *pflags; cpu_relax(); } |