* @entry: window list linkage (msc::win_list)
* @pgoff: page offset into the buffer that this window starts at
* @nr_blocks: number of blocks (pages) in this window
+ * @nr_segs: number of segments in this window (<= @nr_blocks)
* @sgt: array of block descriptors
*/
struct msc_window {
struct list_head entry;
unsigned long pgoff;
unsigned int nr_blocks;
+ unsigned int nr_segs;
struct msc *msc;
struct sg_table sgt;
};
return sg_virt(&win->sgt.sgl[block]);
}
+static inline size_t
+msc_win_actual_bsz(struct msc_window *win, unsigned int block)
+{
+ return win->sgt.sgl[block].length;
+}
+
static inline dma_addr_t
msc_win_baddr(struct msc_window *win, unsigned int block)
{
* with wrapping, last written block contains both the newest and the
* oldest data for this window.
*/
- for (blk = 0; blk < win->nr_blocks; blk++) {
+ for (blk = 0; blk < win->nr_segs; blk++) {
bdesc = msc_win_block(win, blk);
if (msc_block_last_written(bdesc))
return msc_iter_win_advance(iter);
/* block advance */
- if (++iter->block == iter->win->nr_blocks)
+ if (++iter->block == iter->win->nr_segs)
iter->block = 0;
/* no wrapping, sanity check in case there is no last written block */
size_t hw_sz = sizeof(struct msc_block_desc) -
offsetof(struct msc_block_desc, hw_tag);
- for (blk = 0; blk < win->nr_blocks; blk++) {
+ for (blk = 0; blk < win->nr_segs; blk++) {
struct msc_block_desc *bdesc = msc_win_block(win, blk);
memset(&bdesc->hw_tag, 0, hw_sz);
}
static int __msc_buffer_win_alloc(struct msc_window *win,
- unsigned int nr_blocks)
+ unsigned int nr_segs)
{
struct scatterlist *sg_ptr;
void *block;
int i, ret;
- ret = sg_alloc_table(&win->sgt, nr_blocks, GFP_KERNEL);
+ ret = sg_alloc_table(&win->sgt, nr_segs, GFP_KERNEL);
if (ret)
return -ENOMEM;
- for_each_sg(win->sgt.sgl, sg_ptr, nr_blocks, i) {
+ for_each_sg(win->sgt.sgl, sg_ptr, nr_segs, i) {
block = dma_alloc_coherent(msc_dev(win->msc)->parent->parent,
PAGE_SIZE, &sg_dma_address(sg_ptr),
GFP_KERNEL);
sg_set_buf(sg_ptr, block, PAGE_SIZE);
}
- return nr_blocks;
+ return nr_segs;
err_nomem:
for (i--; i >= 0; i--)
}
#ifdef CONFIG_X86
-static void msc_buffer_set_uc(struct msc_window *win, unsigned int nr_blocks)
+static void msc_buffer_set_uc(struct msc_window *win, unsigned int nr_segs)
{
int i;
- for (i = 0; i < nr_blocks; i++)
+ for (i = 0; i < nr_segs; i++)
/* Set the page as uncached */
set_memory_uc((unsigned long)msc_win_block(win, i), 1);
}
{
int i;
- for (i = 0; i < win->nr_blocks; i++)
+ for (i = 0; i < win->nr_segs; i++)
/* Reset the page to write-back */
set_memory_wb((unsigned long)msc_win_block(win, i), 1);
}
#else /* !X86 */
static inline void
-msc_buffer_set_uc(struct msc_window *win, unsigned int nr_blocks) {}
+msc_buffer_set_uc(struct msc_window *win, unsigned int nr_segs) {}
static inline void msc_buffer_set_wb(struct msc_window *win) {}
#endif /* CONFIG_X86 */
struct msc_window,
entry);
- /* This works as long as blocks are page-sized */
win->pgoff = prev->pgoff + prev->nr_blocks;
}
msc_buffer_set_uc(win, ret);
- win->nr_blocks = ret;
+ win->nr_segs = ret;
+ win->nr_blocks = nr_blocks;
if (list_empty(&msc->win_list)) {
msc->base = msc_win_block(win, 0);
{
int i;
- for (i = 0; i < win->nr_blocks; i++) {
+ for (i = 0; i < win->nr_segs; i++) {
struct page *page = sg_page(&win->sgt.sgl[i]);
page->mapping = NULL;
next_win = list_next_entry(win, entry);
}
- for (blk = 0; blk < win->nr_blocks; blk++) {
+ for (blk = 0; blk < win->nr_segs; blk++) {
struct msc_block_desc *bdesc = msc_win_block(win, blk);
memset(bdesc, 0, sizeof(*bdesc));
* Similarly to last window, last block should point
* to the first one.
*/
- if (blk == win->nr_blocks - 1) {
+ if (blk == win->nr_segs - 1) {
sw_tag |= MSC_SW_TAG_LASTBLK;
bdesc->next_blk = msc_win_bpfn(win, 0);
} else {
}
bdesc->sw_tag = sw_tag;
- bdesc->block_sz = PAGE_SIZE / 64;
+ bdesc->block_sz = msc_win_actual_bsz(win, blk) / 64;
}
}
static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff)
{
struct msc_window *win;
+ unsigned int blk;
if (msc->mode == MSC_MODE_SINGLE)
return msc_buffer_contig_get_page(msc, pgoff);
found:
pgoff -= win->pgoff;
- return sg_page(&win->sgt.sgl[pgoff]);
+
+ for (blk = 0; blk < win->nr_segs; blk++) {
+ struct page *page = sg_page(&win->sgt.sgl[blk]);
+ size_t pgsz = PFN_DOWN(msc_win_actual_bsz(win, blk));
+
+ if (pgoff < pgsz)
+ return page + pgoff;
+
+ pgoff -= pgsz;
+ }
+
+ return NULL;
}
/**