struct storvsc_cmd_request {
struct scsi_cmnd *cmd;
- unsigned int bounce_sgl_count;
- struct scatterlist *bounce_sgl;
-
struct hv_device *device;
/* Synchronize the request/response if needed */
}
-static void destroy_bounce_buffer(struct scatterlist *sgl,
- unsigned int sg_count)
-{
- int i;
- struct page *page_buf;
-
- for (i = 0; i < sg_count; i++) {
- page_buf = sg_page((&sgl[i]));
- if (page_buf != NULL)
- __free_page(page_buf);
- }
-
- kfree(sgl);
-}
-
-static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
-{
- int i;
-
- /* No need to check */
- if (sg_count < 2)
- return -1;
-
- /* We have at least 2 sg entries */
- for (i = 0; i < sg_count; i++) {
- if (i == 0) {
- /* make sure 1st one does not have hole */
- if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
- return i;
- } else if (i == sg_count - 1) {
- /* make sure last one does not have hole */
- if (sgl[i].offset != 0)
- return i;
- } else {
- /* make sure no hole in the middle */
- if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
- return i;
- }
- }
- return -1;
-}
-
-static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
- unsigned int sg_count,
- unsigned int len,
- int write)
-{
- int i;
- int num_pages;
- struct scatterlist *bounce_sgl;
- struct page *page_buf;
- unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
-
- num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
-
- bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
- if (!bounce_sgl)
- return NULL;
-
- sg_init_table(bounce_sgl, num_pages);
- for (i = 0; i < num_pages; i++) {
- page_buf = alloc_page(GFP_ATOMIC);
- if (!page_buf)
- goto cleanup;
- sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
- }
-
- return bounce_sgl;
-
-cleanup:
- destroy_bounce_buffer(bounce_sgl, num_pages);
- return NULL;
-}
-
-/* Assume the original sgl has enough room */
-static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
- struct scatterlist *bounce_sgl,
- unsigned int orig_sgl_count,
- unsigned int bounce_sgl_count)
-{
- int i;
- int j = 0;
- unsigned long src, dest;
- unsigned int srclen, destlen, copylen;
- unsigned int total_copied = 0;
- unsigned long bounce_addr = 0;
- unsigned long dest_addr = 0;
- unsigned long flags;
- struct scatterlist *cur_dest_sgl;
- struct scatterlist *cur_src_sgl;
-
- local_irq_save(flags);
- cur_dest_sgl = orig_sgl;
- cur_src_sgl = bounce_sgl;
- for (i = 0; i < orig_sgl_count; i++) {
- dest_addr = (unsigned long)
- kmap_atomic(sg_page(cur_dest_sgl)) +
- cur_dest_sgl->offset;
- dest = dest_addr;
- destlen = cur_dest_sgl->length;
-
- if (bounce_addr == 0)
- bounce_addr = (unsigned long)kmap_atomic(
- sg_page(cur_src_sgl));
-
- while (destlen) {
- src = bounce_addr + cur_src_sgl->offset;
- srclen = cur_src_sgl->length - cur_src_sgl->offset;
-
- copylen = min(srclen, destlen);
- memcpy((void *)dest, (void *)src, copylen);
-
- total_copied += copylen;
- cur_src_sgl->offset += copylen;
- destlen -= copylen;
- dest += copylen;
-
- if (cur_src_sgl->offset == cur_src_sgl->length) {
- /* full */
- kunmap_atomic((void *)bounce_addr);
- j++;
-
- /*
- * It is possible that the number of elements
- * in the bounce buffer may not be equal to
- * the number of elements in the original
- * scatter list. Handle this correctly.
- */
-
- if (j == bounce_sgl_count) {
- /*
- * We are done; cleanup and return.
- */
- kunmap_atomic((void *)(dest_addr -
- cur_dest_sgl->offset));
- local_irq_restore(flags);
- return total_copied;
- }
-
- /* if we need to use another bounce buffer */
- if (destlen || i != orig_sgl_count - 1) {
- cur_src_sgl = sg_next(cur_src_sgl);
- bounce_addr = (unsigned long)
- kmap_atomic(
- sg_page(cur_src_sgl));
- }
- } else if (destlen == 0 && i == orig_sgl_count - 1) {
- /* unmap the last bounce that is < PAGE_SIZE */
- kunmap_atomic((void *)bounce_addr);
- }
- }
-
- kunmap_atomic((void *)(dest_addr - cur_dest_sgl->offset));
- cur_dest_sgl = sg_next(cur_dest_sgl);
- }
-
- local_irq_restore(flags);
-
- return total_copied;
-}
-
-/* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
-static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
- struct scatterlist *bounce_sgl,
- unsigned int orig_sgl_count)
-{
- int i;
- int j = 0;
- unsigned long src, dest;
- unsigned int srclen, destlen, copylen;
- unsigned int total_copied = 0;
- unsigned long bounce_addr = 0;
- unsigned long src_addr = 0;
- unsigned long flags;
- struct scatterlist *cur_src_sgl;
- struct scatterlist *cur_dest_sgl;
-
- local_irq_save(flags);
-
- cur_src_sgl = orig_sgl;
- cur_dest_sgl = bounce_sgl;
-
- for (i = 0; i < orig_sgl_count; i++) {
- src_addr = (unsigned long)
- kmap_atomic(sg_page(cur_src_sgl)) +
- cur_src_sgl->offset;
- src = src_addr;
- srclen = cur_src_sgl->length;
-
- if (bounce_addr == 0)
- bounce_addr = (unsigned long)
- kmap_atomic(sg_page(cur_dest_sgl));
-
- while (srclen) {
- /* assume bounce offset always == 0 */
- dest = bounce_addr + cur_dest_sgl->length;
- destlen = PAGE_SIZE - cur_dest_sgl->length;
-
- copylen = min(srclen, destlen);
- memcpy((void *)dest, (void *)src, copylen);
-
- total_copied += copylen;
- cur_dest_sgl->length += copylen;
- srclen -= copylen;
- src += copylen;
-
- if (cur_dest_sgl->length == PAGE_SIZE) {
- /* full..move to next entry */
- kunmap_atomic((void *)bounce_addr);
- bounce_addr = 0;
- j++;
- }
-
- /* if we need to use another bounce buffer */
- if (srclen && bounce_addr == 0) {
- cur_dest_sgl = sg_next(cur_dest_sgl);
- bounce_addr = (unsigned long)
- kmap_atomic(
- sg_page(cur_dest_sgl));
- }
-
- }
-
- kunmap_atomic((void *)(src_addr - cur_src_sgl->offset));
- cur_src_sgl = sg_next(cur_src_sgl);
- }
-
- if (bounce_addr)
- kunmap_atomic((void *)bounce_addr);
-
- local_irq_restore(flags);
-
- return total_copied;
-}
-
static void handle_sc_creation(struct vmbus_channel *new_sc)
{
struct hv_device *device = new_sc->primary_channel->device_obj;
host = stor_dev->host;
vm_srb = &cmd_request->vstor_packet.vm_srb;
- if (cmd_request->bounce_sgl_count) {
- if (vm_srb->data_in == READ_TYPE)
- copy_from_bounce_buffer(scsi_sglist(scmnd),
- cmd_request->bounce_sgl,
- scsi_sg_count(scmnd),
- cmd_request->bounce_sgl_count);
- destroy_bounce_buffer(cmd_request->bounce_sgl,
- cmd_request->bounce_sgl_count);
- }
scmnd->result = vm_srb->scsi_status;
blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
+ /* Ensure there are no gaps in presented sgls */
+ blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
+
sdevice->no_write_same = 1;
/*
payload_sz = sizeof(cmd_request->mpb);
if (sg_count) {
- /* check if we need to bounce the sgl */
- if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
- cmd_request->bounce_sgl =
- create_bounce_buffer(sgl, sg_count,
- length,
- vm_srb->data_in);
- if (!cmd_request->bounce_sgl)
- return SCSI_MLQUEUE_HOST_BUSY;
-
- cmd_request->bounce_sgl_count =
- ALIGN(length, PAGE_SIZE) >> PAGE_SHIFT;
-
- if (vm_srb->data_in == WRITE_TYPE)
- copy_to_bounce_buffer(sgl,
- cmd_request->bounce_sgl, sg_count);
-
- sgl = cmd_request->bounce_sgl;
- sg_count = cmd_request->bounce_sgl_count;
- }
-
-
if (sg_count > MAX_PAGE_BUFFER_COUNT) {
payload_sz = (sg_count * sizeof(void *) +
sizeof(struct vmbus_packet_mpb_array));
payload = kmalloc(payload_sz, GFP_ATOMIC);
- if (!payload) {
- if (cmd_request->bounce_sgl_count)
- destroy_bounce_buffer(
- cmd_request->bounce_sgl,
- cmd_request->bounce_sgl_count);
-
- return SCSI_MLQUEUE_DEVICE_BUSY;
- }
+ if (!payload)
+ return SCSI_MLQUEUE_DEVICE_BUSY;
}
payload->range.len = length;
if (ret == -EAGAIN) {
/* no more space */
-
- if (cmd_request->bounce_sgl_count)
- destroy_bounce_buffer(cmd_request->bounce_sgl,
- cmd_request->bounce_sgl_count);
-
return SCSI_MLQUEUE_DEVICE_BUSY;
}
projects / cascardo / linux.git / blobdiff