Clean up: fix a mixed sign comparison in sg_init_table() accidentally
introduced by commit d6ec0842. The sign of the loop index variable
should match the sign of the "nents" argument.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
Clean up: fix a mixed sign comparison in sg_last() accidentally
introduced by commit 70eb8040. The sign of the loop index variable
should match the sign of the "nents" argument.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
Since we are using the last entry in the list, clear any possible
termination bit that may have already been set. Pointed out by Rusty.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
x86_32 CONFIG_HIGHMEM64G with 5GB RAM hung when booting, after issuing
some "request_module: runaway loop modprobe binfmt-0000" messages in
trying to exec /sbin/init.
The binprm buf doesn't see the right ".ELF" header because sg_phys()
is providing the wrong physical addresses for high pages: a 32-bit
unsigned long is too small in this case, we need to use dma_addr_t.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Most drivers need to set length and offset as well, so may as well fold
those three lines into one.
Add sg_assign_page() for those two locations that only needed to set
the page, where the offset/length is set outside of the function context.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Change the page member of the scatterlist structure to be an unsigned
long, and encode more stuff in the lower bits:
- Bits 0 and 1 zero: this is a normal sg entry. Next sg entry is located
at sg + 1.
- Bit 0 set: this is a chain entry, the next real entry is at ->page_link
with the two low bits masked off.
- Bit 1 set: this is the final entry in the sg entry. sg_next() will return
NULL when passed such an entry.
It's thus important that sg table users use the proper accessors to get
and set the page member.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The core of the patch - allow the last sg element in a scatterlist
table to point to the start of a new table. We overload the LSB of
the page pointer to indicate whether this is a valid sg entry, or
merely a link to the next list.
Includes a fix from Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
correcting the ifdef ARCH_HAS_SG_CHAIN guarding sg_last().
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds a const modifier to the buf argument of sg_set_buf and
sg_init_one. This lets people call it with pointers that are const.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
sg_init_one is a nice tool for the block layer. However, users
of struct scatterlist in other subsystems don't usually need the
DMA attributes. For them it's a waste of time and space to
initialise the whole struct scatterlist structure.
Therefore this patch adds a new function sg_set_buf to initialise
a scatterlist without zeroing the DMA attributes.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
