mem_copy->copy_buf = NULL;
}
+#define IS_4K_ALIGNED(addr) ((((unsigned long)addr) & ~MASK_4K) == 0)
+
/**
* iser_sg_to_page_vec - Translates scatterlist entries to physical addresses
* and returns the length of resulting physical address array (may be less than
* where --few fragments of the same page-- are present in the SG as
* consecutive elements. Also, it handles one entry SG.
*/
+
static int iser_sg_to_page_vec(struct iser_data_buf *data,
struct iser_page_vec *page_vec,
struct ib_device *ibdev)
{
- struct scatterlist *sgl = (struct scatterlist *)data->buf;
- struct scatterlist *sg;
- u64 first_addr, last_addr, page;
- int end_aligned;
- unsigned int cur_page = 0;
+ struct scatterlist *sg, *sgl = (struct scatterlist *)data->buf;
+ u64 start_addr, end_addr, page, chunk_start = 0;
unsigned long total_sz = 0;
- int i;
+ unsigned int dma_len;
+ int i, new_chunk, cur_page, last_ent = data->dma_nents - 1;
/* compute the offset of first element */
page_vec->offset = (u64) sgl[0].offset & ~MASK_4K;
+ new_chunk = 1;
+ cur_page = 0;
for_each_sg(sgl, sg, data->dma_nents, i) {
- unsigned int dma_len = ib_sg_dma_len(ibdev, sg);
-
+ start_addr = ib_sg_dma_address(ibdev, sg);
+ if (new_chunk)
+ chunk_start = start_addr;
+ dma_len = ib_sg_dma_len(ibdev, sg);
+ end_addr = start_addr + dma_len;
total_sz += dma_len;
- first_addr = ib_sg_dma_address(ibdev, sg);
- last_addr = first_addr + dma_len;
-
- end_aligned = !(last_addr & ~MASK_4K);
-
- /* continue to collect page fragments till aligned or SG ends */
- while (!end_aligned && (i + 1 < data->dma_nents)) {
- sg = sg_next(sg);
- i++;
- dma_len = ib_sg_dma_len(ibdev, sg);
- total_sz += dma_len;
- last_addr = ib_sg_dma_address(ibdev, sg) + dma_len;
- end_aligned = !(last_addr & ~MASK_4K);
+ /* collect page fragments until aligned or end of SG list */
+ if (!IS_4K_ALIGNED(end_addr) && i < last_ent) {
+ new_chunk = 0;
+ continue;
}
-
- /* handle the 1st page in the 1st DMA element */
- if (cur_page == 0) {
- page = first_addr & MASK_4K;
- page_vec->pages[cur_page] = page;
- cur_page++;
+ new_chunk = 1;
+
+ /* address of the first page in the contiguous chunk;
+ masking relevant for the very first SG entry,
+ which might be unaligned */
+ page = chunk_start & MASK_4K;
+ do {
+ page_vec->pages[cur_page++] = page;
page += SIZE_4K;
- } else
- page = first_addr;
-
- for (; page < last_addr; page += SIZE_4K) {
- page_vec->pages[cur_page] = page;
- cur_page++;
- }
-
+ } while (page < end_addr);
}
+
page_vec->data_size = total_sz;
iser_dbg("page_vec->data_size:%d cur_page %d\n", page_vec->data_size,cur_page);
return cur_page;
}
-#define IS_4K_ALIGNED(addr) ((((unsigned long)addr) & ~MASK_4K) == 0)
/**
* iser_data_buf_aligned_len - Tries to determine the maximal correctly aligned
* the number of entries which are aligned correctly. Supports the case where
* consecutive SG elements are actually fragments of the same physcial page.
*/
-static unsigned int iser_data_buf_aligned_len(struct iser_data_buf *data,
- struct ib_device *ibdev)
+static int iser_data_buf_aligned_len(struct iser_data_buf *data,
+ struct ib_device *ibdev)
{
- struct scatterlist *sgl, *sg;
- u64 end_addr, next_addr;
- int i, cnt;
- unsigned int ret_len = 0;
+ struct scatterlist *sgl, *sg, *next_sg = NULL;
+ u64 start_addr, end_addr;
+ int i, ret_len, start_check = 0;
+
+ if (data->dma_nents == 1)
+ return 1;
sgl = (struct scatterlist *)data->buf;
+ start_addr = ib_sg_dma_address(ibdev, sgl);
- cnt = 0;
for_each_sg(sgl, sg, data->dma_nents, i) {
- /* iser_dbg("Checking sg iobuf [%d]: phys=0x%08lX "
- "offset: %ld sz: %ld\n", i,
- (unsigned long)sg_phys(sg),
- (unsigned long)sg->offset,
- (unsigned long)sg->length); */
- end_addr = ib_sg_dma_address(ibdev, sg) +
- ib_sg_dma_len(ibdev, sg);
- /* iser_dbg("Checking sg iobuf end address "
- "0x%08lX\n", end_addr); */
- if (i + 1 < data->dma_nents) {
- next_addr = ib_sg_dma_address(ibdev, sg_next(sg));
- /* are i, i+1 fragments of the same page? */
- if (end_addr == next_addr) {
- cnt++;
- continue;
- } else if (!IS_4K_ALIGNED(end_addr)) {
- ret_len = cnt + 1;
- break;
- }
- }
- cnt++;
+ if (start_check && !IS_4K_ALIGNED(start_addr))
+ break;
+
+ next_sg = sg_next(sg);
+ if (!next_sg)
+ break;
+
+ end_addr = start_addr + ib_sg_dma_len(ibdev, sg);
+ start_addr = ib_sg_dma_address(ibdev, next_sg);
+
+ if (end_addr == start_addr) {
+ start_check = 0;
+ continue;
+ } else
+ start_check = 1;
+
+ if (!IS_4K_ALIGNED(end_addr))
+ break;
}
- if (i == data->dma_nents)
- ret_len = cnt; /* loop ended */
+ ret_len = (next_sg) ? i : i+1;
iser_dbg("Found %d aligned entries out of %d in sg:0x%p\n",
ret_len, data->dma_nents, data);
return ret_len;
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff