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author | Roger Pau Monne <roger.pau@citrix.com> | 2014-02-04 14:26:15 +0400 |
---|---|---|
committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2014-02-07 22:03:53 +0400 |
commit | 80bfa2f6e2e81049fc6cd3bfaeedcb64db3a9ba6 (patch) | |
tree | 8f0ac299cbc57192b2cf23de645799fc1b879b4c /include/xen/interface/io/blkif.h | |
parent | c05f3e3c85df1d89673e00cee7ece5ae4eb4c6ec (diff) | |
download | linux-80bfa2f6e2e81049fc6cd3bfaeedcb64db3a9ba6.tar.xz |
xen-blkif: drop struct blkif_request_segment_aligned
This was wrongly introduced in commit 402b27f9, the only difference
between blkif_request_segment_aligned and blkif_request_segment is
that the former has a named padding, while both share the same
memory layout.
Also correct a few minor glitches in the description, including for it
to no longer assume PAGE_SIZE == 4096.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
[Description fix by Jan Beulich]
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reported-by: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Matt Rushton <mrushton@amazon.com>
Cc: Matt Wilson <msw@amazon.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'include/xen/interface/io/blkif.h')
-rw-r--r-- | include/xen/interface/io/blkif.h | 34 |
1 files changed, 14 insertions, 20 deletions
diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h index ae665ac59c36..32ec05a6572f 100644 --- a/include/xen/interface/io/blkif.h +++ b/include/xen/interface/io/blkif.h @@ -113,13 +113,13 @@ typedef uint64_t blkif_sector_t; * it's less than the number provided by the backend. The indirect_grefs field * in blkif_request_indirect should be filled by the frontend with the * grant references of the pages that are holding the indirect segments. - * This pages are filled with an array of blkif_request_segment_aligned - * that hold the information about the segments. The number of indirect - * pages to use is determined by the maximum number of segments - * a indirect request contains. Every indirect page can contain a maximum - * of 512 segments (PAGE_SIZE/sizeof(blkif_request_segment_aligned)), - * so to calculate the number of indirect pages to use we have to do - * ceil(indirect_segments/512). + * These pages are filled with an array of blkif_request_segment that hold the + * information about the segments. The number of indirect pages to use is + * determined by the number of segments an indirect request contains. Every + * indirect page can contain a maximum of + * (PAGE_SIZE / sizeof(struct blkif_request_segment)) segments, so to + * calculate the number of indirect pages to use we have to do + * ceil(indirect_segments / (PAGE_SIZE / sizeof(struct blkif_request_segment))). * * If a backend does not recognize BLKIF_OP_INDIRECT, it should *not* * create the "feature-max-indirect-segments" node! @@ -135,13 +135,12 @@ typedef uint64_t blkif_sector_t; #define BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST 8 -struct blkif_request_segment_aligned { - grant_ref_t gref; /* reference to I/O buffer frame */ - /* @first_sect: first sector in frame to transfer (inclusive). */ - /* @last_sect: last sector in frame to transfer (inclusive). */ - uint8_t first_sect, last_sect; - uint16_t _pad; /* padding to make it 8 bytes, so it's cache-aligned */ -} __attribute__((__packed__)); +struct blkif_request_segment { + grant_ref_t gref; /* reference to I/O buffer frame */ + /* @first_sect: first sector in frame to transfer (inclusive). */ + /* @last_sect: last sector in frame to transfer (inclusive). */ + uint8_t first_sect, last_sect; +}; struct blkif_request_rw { uint8_t nr_segments; /* number of segments */ @@ -151,12 +150,7 @@ struct blkif_request_rw { #endif uint64_t id; /* private guest value, echoed in resp */ blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ - struct blkif_request_segment { - grant_ref_t gref; /* reference to I/O buffer frame */ - /* @first_sect: first sector in frame to transfer (inclusive). */ - /* @last_sect: last sector in frame to transfer (inclusive). */ - uint8_t first_sect, last_sect; - } seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; } __attribute__((__packed__)); struct blkif_request_discard { |