[SCSI] st: convert dio path to use st_scsi_execute

This patch converts the dio path (mmap) to use st_scsi_execute. IOW,
it removes scsi_execute_async in the non dio path.

scsi_execute_async has gone! This also remove unused st_sleep_done.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Kai Makisara <Kai.Makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

2 files changed, 24 insertions, 53 deletions

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 390689d5fdf3..fec5568c711a 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -191,9 +191,9 @@ static int from_buffer(struct st_buffer *, char __user *, int);
 static void move_buffer_data(struct st_buffer *, int);
 static void buf_to_sg(struct st_buffer *, unsigned int);
 
-static int sgl_map_user_pages(struct scatterlist *, const unsigned int, 
+static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
                               unsigned long, size_t, int);
-static int sgl_unmap_user_pages(struct scatterlist *, const unsigned int, int);
+static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 
 static int st_probe(struct device *);
 static int st_remove(struct device *);
@@ -435,22 +435,6 @@ static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
         return (-EIO);
 }
 
-
-/* Wakeup from interrupt */
-static void st_sleep_done(void *data, char *sense, int result, int resid)
-{
-        struct st_request *SRpnt = data;
-        struct scsi_tape *STp = SRpnt->stp;
-
-        memcpy(SRpnt->sense, sense, SCSI_SENSE_BUFFERSIZE);
-        (STp->buffer)->cmdstat.midlevel_result = SRpnt->result = result;
-        (STp->buffer)->cmdstat.residual = resid;
-        DEB( STp->write_pending = 0; )
-
-        if (SRpnt->waiting)
-                complete(SRpnt->waiting);
-}
-
 static struct st_request *st_allocate_request(struct scsi_tape *stp)
 {
         struct st_request *streq;
@@ -566,7 +550,10 @@ st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd
         init_completion(waiting);
         SRpnt->waiting = waiting;
 
-        if (!STp->buffer->do_dio) {
+        if (STp->buffer->do_dio) {
+                mdata->nr_entries = STp->buffer->sg_segs;
+                mdata->pages = STp->buffer->mapped_pages;
+        } else {
                 buf_to_sg(STp->buffer, bytes);
 
                 mdata->nr_entries =
@@ -579,16 +566,8 @@ st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd
         STp->buffer->cmdstat.have_sense = 0;
         STp->buffer->syscall_result = 0;
 
-        if (STp->buffer->do_dio)
-                ret = scsi_execute_async(STp->device, cmd, COMMAND_SIZE(cmd[0]),
-                                         direction, &((STp->buffer)->sg[0]),
-                                         bytes, (STp->buffer)->sg_segs, timeout,
-                                         retries, SRpnt, st_sleep_done,
-                                         GFP_KERNEL);
-        else
-                ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes,
-                                      timeout, retries);
-
+        ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
+                              retries);
         if (ret) {
                 /* could not allocate the buffer or request was too large */
                 (STp->buffer)->syscall_result = (-EBUSY);
@@ -1540,8 +1519,8 @@ static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
 
         if (i && ((unsigned long)buf & queue_dma_alignment(
                                         STp->device->request_queue)) == 0) {
-                i = sgl_map_user_pages(&(STbp->sg[0]), STbp->use_sg,
-                                      (unsigned long)buf, count, (is_read ? READ : WRITE));
+                i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
+                                       count, (is_read ? READ : WRITE));
                 if (i > 0) {
                         STbp->do_dio = i;
                         STbp->buffer_bytes = 0;   /* can be used as transfer counter */
@@ -1595,7 +1574,7 @@ static void release_buffering(struct scsi_tape *STp, int is_read)
 
         STbp = STp->buffer;
         if (STbp->do_dio) {
-                sgl_unmap_user_pages(&(STbp->sg[0]), STbp->do_dio, is_read);
+                sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
                 STbp->do_dio = 0;
                 STbp->sg_segs = 0;
         }
@@ -4647,14 +4626,16 @@ out:
 }
 
 /* The following functions may be useful for a larger audience. */
-static int sgl_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages, 
-                              unsigned long uaddr, size_t count, int rw)
+static int sgl_map_user_pages(struct st_buffer *STbp,
+                              const unsigned int max_pages, unsigned long uaddr,
+                              size_t count, int rw)
 {
         unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
         unsigned long start = uaddr >> PAGE_SHIFT;
         const int nr_pages = end - start;
         int res, i, j;
         struct page **pages;
+        struct rq_map_data *mdata = &STbp->map_data;
 
         /* User attempted Overflow! */
         if ((uaddr + count) < uaddr)
@@ -4696,24 +4677,11 @@ static int sgl_map_user_pages(struct scatterlist *sgl, const unsigned int max_pa
                 flush_dcache_page(pages[i]);
         }
 
-        /* Populate the scatter/gather list */
-        sg_set_page(&sgl[0], pages[0], 0, uaddr & ~PAGE_MASK);
-        if (nr_pages > 1) {
-                sgl[0].length = PAGE_SIZE - sgl[0].offset;
-                count -= sgl[0].length;
-                for (i=1; i < nr_pages ; i++) {
-                        sg_set_page(&sgl[i], pages[i],
-                                    count < PAGE_SIZE ? count : PAGE_SIZE, 0);;
-                        count -= PAGE_SIZE;
-                }
-        }
-        else {
-                sgl[0].length = count;
-        }
+        mdata->offset = uaddr & ~PAGE_MASK;
+        mdata->page_order = 0;
+        STbp->mapped_pages = pages;
 
-        kfree(pages);
         return nr_pages;
-
  out_unmap:
         if (res > 0) {
                 for (j=0; j < res; j++)
@@ -4726,13 +4694,13 @@ static int sgl_map_user_pages(struct scatterlist *sgl, const unsigned int max_pa
 
 
 /* And unmap them... */
-static int sgl_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
-                                int dirtied)
+static int sgl_unmap_user_pages(struct st_buffer *STbp,
+                                const unsigned int nr_pages, int dirtied)
 {
         int i;
 
         for (i=0; i < nr_pages; i++) {
-                struct page *page = sg_page(&sgl[i]);
+                struct page *page = STbp->mapped_pages[i];
 
                 if (dirtied)
                         SetPageDirty(page);
@@ -4741,6 +4709,8 @@ static int sgl_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_p
                  */
                 page_cache_release(page);
         }
+        kfree(STbp->mapped_pages);
+        STbp->mapped_pages = NULL;
 
         return 0;
 }
diff --git a/drivers/scsi/st.h b/drivers/scsi/st.h
index 77302fa8608a..d80926f9c6e3 100644
--- a/drivers/scsi/st.h
+++ b/drivers/scsi/st.h
@@ -46,6 +46,7 @@ struct st_buffer {
         struct st_request *last_SRpnt;
         struct st_cmdstatus cmdstat;
         struct page **reserved_pages;
+        struct page **mapped_pages;
         struct rq_map_data map_data;
         unsigned char *b_data;
         unsigned short use_sg;  /* zero or max number of s/g segments for this adapter */