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synced 2024-09-06 02:50:43 +00:00
floppy: always use the track buffer
Always use the track buffer that is already used for addresses outside the 16MB address capability of the floppy controller. This allows to remove a lot of code that relies on kernel virtual addresses. With this gone there is just a single place left that looks at the bio, which can be converted to memcpy_{from,to}_page, thus removing the need for the extra block-layer bounce buffering for highmem pages. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210406061755.811522-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
parent
4c6e5bc8c0
commit
3d86739c63
1 changed files with 25 additions and 111 deletions
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@ -2399,11 +2399,10 @@ static void rw_interrupt(void)
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probing = 0;
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}
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if (CT(raw_cmd->cmd[COMMAND]) != FD_READ ||
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raw_cmd->kernel_data == bio_data(current_req->bio)) {
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if (CT(raw_cmd->cmd[COMMAND]) != FD_READ) {
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/* transfer directly from buffer */
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cont->done(1);
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} else if (CT(raw_cmd->cmd[COMMAND]) == FD_READ) {
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} else {
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buffer_track = raw_cmd->track;
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buffer_drive = current_drive;
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INFBOUND(buffer_max, nr_sectors + fsector_t);
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@ -2411,27 +2410,6 @@ static void rw_interrupt(void)
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cont->redo();
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}
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/* Compute maximal contiguous buffer size. */
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static int buffer_chain_size(void)
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{
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struct bio_vec bv;
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int size;
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struct req_iterator iter;
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char *base;
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base = bio_data(current_req->bio);
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size = 0;
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rq_for_each_segment(bv, current_req, iter) {
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if (page_address(bv.bv_page) + bv.bv_offset != base + size)
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break;
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size += bv.bv_len;
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}
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return size >> 9;
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}
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/* Compute the maximal transfer size */
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static int transfer_size(int ssize, int max_sector, int max_size)
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{
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@ -2453,7 +2431,6 @@ static void copy_buffer(int ssize, int max_sector, int max_sector_2)
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{
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int remaining; /* number of transferred 512-byte sectors */
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struct bio_vec bv;
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char *buffer;
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char *dma_buffer;
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int size;
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struct req_iterator iter;
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@ -2492,8 +2469,6 @@ static void copy_buffer(int ssize, int max_sector, int max_sector_2)
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size = bv.bv_len;
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SUPBOUND(size, remaining);
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buffer = page_address(bv.bv_page) + bv.bv_offset;
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if (dma_buffer + size >
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floppy_track_buffer + (max_buffer_sectors << 10) ||
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dma_buffer < floppy_track_buffer) {
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@ -2509,13 +2484,13 @@ static void copy_buffer(int ssize, int max_sector, int max_sector_2)
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pr_info("write\n");
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break;
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}
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if (((unsigned long)buffer) % 512)
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DPRINT("%p buffer not aligned\n", buffer);
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if (CT(raw_cmd->cmd[COMMAND]) == FD_READ)
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memcpy(buffer, dma_buffer, size);
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memcpy_to_page(bv.bv_page, bv.bv_offset, dma_buffer,
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size);
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else
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memcpy(dma_buffer, buffer, size);
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memcpy_from_page(dma_buffer, bv.bv_page, bv.bv_offset,
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size);
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remaining -= size;
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dma_buffer += size;
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@ -2690,54 +2665,6 @@ static int make_raw_rw_request(void)
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raw_cmd->flags &= ~FD_RAW_WRITE;
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raw_cmd->flags |= FD_RAW_READ;
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raw_cmd->cmd[COMMAND] = FM_MODE(_floppy, FD_READ);
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} else if ((unsigned long)bio_data(current_req->bio) < MAX_DMA_ADDRESS) {
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unsigned long dma_limit;
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int direct, indirect;
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indirect =
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transfer_size(ssize, max_sector,
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max_buffer_sectors * 2) - fsector_t;
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/*
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* Do NOT use minimum() here---MAX_DMA_ADDRESS is 64 bits wide
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* on a 64 bit machine!
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*/
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max_size = buffer_chain_size();
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dma_limit = (MAX_DMA_ADDRESS -
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((unsigned long)bio_data(current_req->bio))) >> 9;
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if ((unsigned long)max_size > dma_limit)
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max_size = dma_limit;
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/* 64 kb boundaries */
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if (CROSS_64KB(bio_data(current_req->bio), max_size << 9))
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max_size = (K_64 -
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((unsigned long)bio_data(current_req->bio)) %
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K_64) >> 9;
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direct = transfer_size(ssize, max_sector, max_size) - fsector_t;
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/*
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* We try to read tracks, but if we get too many errors, we
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* go back to reading just one sector at a time.
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*
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* This means we should be able to read a sector even if there
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* are other bad sectors on this track.
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*/
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if (!direct ||
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(indirect * 2 > direct * 3 &&
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*errors < drive_params[current_drive].max_errors.read_track &&
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((!probing ||
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(drive_params[current_drive].read_track & (1 << drive_state[current_drive].probed_format)))))) {
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max_size = blk_rq_sectors(current_req);
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} else {
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raw_cmd->kernel_data = bio_data(current_req->bio);
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raw_cmd->length = current_count_sectors << 9;
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if (raw_cmd->length == 0) {
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DPRINT("%s: zero dma transfer attempted\n", __func__);
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DPRINT("indirect=%d direct=%d fsector_t=%d\n",
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indirect, direct, fsector_t);
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return 0;
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}
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virtualdmabug_workaround();
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return 2;
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}
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}
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if (CT(raw_cmd->cmd[COMMAND]) == FD_READ)
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@ -2781,19 +2708,17 @@ static int make_raw_rw_request(void)
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raw_cmd->length = ((raw_cmd->length - 1) | (ssize - 1)) + 1;
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raw_cmd->length <<= 9;
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if ((raw_cmd->length < current_count_sectors << 9) ||
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(raw_cmd->kernel_data != bio_data(current_req->bio) &&
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CT(raw_cmd->cmd[COMMAND]) == FD_WRITE &&
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(CT(raw_cmd->cmd[COMMAND]) == FD_WRITE &&
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(aligned_sector_t + (raw_cmd->length >> 9) > buffer_max ||
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aligned_sector_t < buffer_min)) ||
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raw_cmd->length % (128 << raw_cmd->cmd[SIZECODE]) ||
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raw_cmd->length <= 0 || current_count_sectors <= 0) {
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DPRINT("fractionary current count b=%lx s=%lx\n",
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raw_cmd->length, current_count_sectors);
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if (raw_cmd->kernel_data != bio_data(current_req->bio))
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pr_info("addr=%d, length=%ld\n",
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(int)((raw_cmd->kernel_data -
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floppy_track_buffer) >> 9),
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current_count_sectors);
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pr_info("addr=%d, length=%ld\n",
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(int)((raw_cmd->kernel_data -
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floppy_track_buffer) >> 9),
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current_count_sectors);
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pr_info("st=%d ast=%d mse=%d msi=%d\n",
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fsector_t, aligned_sector_t, max_sector, max_size);
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pr_info("ssize=%x SIZECODE=%d\n", ssize, raw_cmd->cmd[SIZECODE]);
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@ -2807,31 +2732,21 @@ static int make_raw_rw_request(void)
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return 0;
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}
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if (raw_cmd->kernel_data != bio_data(current_req->bio)) {
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if (raw_cmd->kernel_data < floppy_track_buffer ||
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current_count_sectors < 0 ||
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raw_cmd->length < 0 ||
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raw_cmd->kernel_data + raw_cmd->length >
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floppy_track_buffer + (max_buffer_sectors << 10)) {
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DPRINT("buffer overrun in schedule dma\n");
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pr_info("fsector_t=%d buffer_min=%d current_count=%ld\n",
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fsector_t, buffer_min, raw_cmd->length >> 9);
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pr_info("current_count_sectors=%ld\n",
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current_count_sectors);
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if (CT(raw_cmd->cmd[COMMAND]) == FD_READ)
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pr_info("read\n");
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if (CT(raw_cmd->cmd[COMMAND]) == FD_WRITE)
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pr_info("write\n");
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return 0;
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}
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} else if (raw_cmd->length > blk_rq_bytes(current_req) ||
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current_count_sectors > blk_rq_sectors(current_req)) {
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DPRINT("buffer overrun in direct transfer\n");
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if (raw_cmd->kernel_data < floppy_track_buffer ||
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current_count_sectors < 0 ||
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raw_cmd->length < 0 ||
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raw_cmd->kernel_data + raw_cmd->length >
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floppy_track_buffer + (max_buffer_sectors << 10)) {
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DPRINT("buffer overrun in schedule dma\n");
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pr_info("fsector_t=%d buffer_min=%d current_count=%ld\n",
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fsector_t, buffer_min, raw_cmd->length >> 9);
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pr_info("current_count_sectors=%ld\n",
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current_count_sectors);
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if (CT(raw_cmd->cmd[COMMAND]) == FD_READ)
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pr_info("read\n");
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if (CT(raw_cmd->cmd[COMMAND]) == FD_WRITE)
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pr_info("write\n");
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return 0;
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} else if (raw_cmd->length < current_count_sectors << 9) {
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DPRINT("more sectors than bytes\n");
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pr_info("bytes=%ld\n", raw_cmd->length >> 9);
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pr_info("sectors=%ld\n", current_count_sectors);
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}
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if (raw_cmd->length == 0) {
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DPRINT("zero dma transfer attempted from make_raw_request\n");
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@ -4597,7 +4512,6 @@ static int floppy_alloc_disk(unsigned int drive, unsigned int type)
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return err;
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}
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blk_queue_bounce_limit(disk->queue, BLK_BOUNCE_HIGH);
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blk_queue_max_hw_sectors(disk->queue, 64);
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disk->major = FLOPPY_MAJOR;
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disk->first_minor = TOMINOR(drive) | (type << 2);
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