1 files changed, 68 insertions, 71 deletions

diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c
index 08413e6a075f..a6c0eb09c515 100644
--- a/drivers/hwtracing/intel_th/msu.c
+++ b/drivers/hwtracing/intel_th/msu.c
@@ -95,8 +95,8 @@ struct msc_iter {
 	struct msc_window	*start_win;
 	struct msc_window	*win;
 	unsigned long		offset;
-	int			start_block;
-	int			block;
+	struct scatterlist	*start_block;
+	struct scatterlist	*block;
 	unsigned int		block_off;
 	unsigned int		wrap_count;
 	unsigned int		eof;
@@ -269,28 +269,25 @@ static inline bool msc_block_is_empty(struct msc_block_desc *bdesc)
 	return false;
 }
 
-static inline struct msc_block_desc *
-msc_win_block(struct msc_window *win, unsigned int block)
+static inline struct scatterlist *msc_win_base_sg(struct msc_window *win)
 {
-	return sg_virt(&win->sgt->sgl[block]);
+	return win->sgt->sgl;
 }
 
-static inline size_t
-msc_win_actual_bsz(struct msc_window *win, unsigned int block)
+static inline struct msc_block_desc *msc_win_base(struct msc_window *win)
 {
-	return win->sgt->sgl[block].length;
+	return sg_virt(msc_win_base_sg(win));
 }
 
-static inline dma_addr_t
-msc_win_baddr(struct msc_window *win, unsigned int block)
+static inline dma_addr_t msc_win_base_dma(struct msc_window *win)
 {
-	return sg_dma_address(&win->sgt->sgl[block]);
+	return sg_dma_address(msc_win_base_sg(win));
 }
 
 static inline unsigned long
-msc_win_bpfn(struct msc_window *win, unsigned int block)
+msc_win_base_pfn(struct msc_window *win)
 {
-	return msc_win_baddr(win, block) >> PAGE_SHIFT;
+	return PFN_DOWN(msc_win_base_dma(win));
 }
 
 /**
@@ -320,11 +317,12 @@ static struct msc_window *msc_next_window(struct msc_window *win)
 
 static size_t msc_win_total_sz(struct msc_window *win)
 {
+	struct scatterlist *sg;
 	unsigned int blk;
 	size_t size = 0;
 
-	for (blk = 0; blk < win->nr_segs; blk++) {
-		struct msc_block_desc *bdesc = msc_win_block(win, blk);
+	for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
+		struct msc_block_desc *bdesc = sg_virt(sg);
 
 		if (msc_block_wrapped(bdesc))
 			return win->nr_blocks << PAGE_SHIFT;
@@ -365,7 +363,7 @@ msc_find_window(struct msc *msc, struct sg_table *sgt, bool nonempty)
 			found++;
 
 		/* skip the empty ones */
-		if (nonempty && msc_block_is_empty(msc_win_block(win, 0)))
+		if (nonempty && msc_block_is_empty(msc_win_base(win)))
 			continue;
 
 		if (found)
@@ -399,44 +397,38 @@ static struct msc_window *msc_oldest_window(struct msc *msc)
 }
 
 /**
- * msc_win_oldest_block() - locate the oldest block in a given window
+ * msc_win_oldest_sg() - locate the oldest block in a given window
  * @win:	window to look at
  *
  * Return:	index of the block with the oldest data
  */
-static unsigned int msc_win_oldest_block(struct msc_window *win)
+static struct scatterlist *msc_win_oldest_sg(struct msc_window *win)
 {
 	unsigned int blk;
-	struct msc_block_desc *bdesc = msc_win_block(win, 0);
+	struct scatterlist *sg;
+	struct msc_block_desc *bdesc = msc_win_base(win);
 
 	/* without wrapping, first block is the oldest */
 	if (!msc_block_wrapped(bdesc))
-		return 0;
+		return msc_win_base_sg(win);
 
 	/*
 	 * with wrapping, last written block contains both the newest and the
 	 * oldest data for this window.
 	 */
-	for (blk = 0; blk < win->nr_segs; blk++) {
-		bdesc = msc_win_block(win, blk);
+	for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
+		struct msc_block_desc *bdesc = sg_virt(sg);
 
 		if (msc_block_last_written(bdesc))
-			return blk;
+			return sg;
 	}
 
-	return 0;
+	return msc_win_base_sg(win);
 }
 
 static struct msc_block_desc *msc_iter_bdesc(struct msc_iter *iter)
 {
-	return msc_win_block(iter->win, iter->block);
-}
-
-static void msc_iter_init(struct msc_iter *iter)
-{
-	memset(iter, 0, sizeof(*iter));
-	iter->start_block = -1;
-	iter->block = -1;
+	return sg_virt(iter->block);
 }
 
 static struct msc_iter *msc_iter_install(struct msc *msc)
@@ -461,7 +453,6 @@ static struct msc_iter *msc_iter_install(struct msc *msc)
 		goto unlock;
 	}
 
-	msc_iter_init(iter);
 	iter->msc = msc;
 
 	list_add_tail(&iter->entry, &msc->iter_list);
@@ -482,10 +473,10 @@ static void msc_iter_remove(struct msc_iter *iter, struct msc *msc)
 
 static void msc_iter_block_start(struct msc_iter *iter)
 {
-	if (iter->start_block != -1)
+	if (iter->start_block)
 		return;
 
-	iter->start_block = msc_win_oldest_block(iter->win);
+	iter->start_block = msc_win_oldest_sg(iter->win);
 	iter->block = iter->start_block;
 	iter->wrap_count = 0;
 
@@ -509,7 +500,7 @@ static int msc_iter_win_start(struct msc_iter *iter, struct msc *msc)
 		return -EINVAL;
 
 	iter->win = iter->start_win;
-	iter->start_block = -1;
+	iter->start_block = NULL;
 
 	msc_iter_block_start(iter);
 
@@ -519,7 +510,7 @@ static int msc_iter_win_start(struct msc_iter *iter, struct msc *msc)
 static int msc_iter_win_advance(struct msc_iter *iter)
 {
 	iter->win = msc_next_window(iter->win);
-	iter->start_block = -1;
+	iter->start_block = NULL;
 
 	if (iter->win == iter->start_win) {
 		iter->eof++;
@@ -549,8 +540,10 @@ static int msc_iter_block_advance(struct msc_iter *iter)
 		return msc_iter_win_advance(iter);
 
 	/* block advance */
-	if (++iter->block == iter->win->nr_segs)
-		iter->block = 0;
+	if (sg_is_last(iter->block))
+		iter->block = msc_win_base_sg(iter->win);
+	else
+		iter->block = sg_next(iter->block);
 
 	/* no wrapping, sanity check in case there is no last written block */
 	if (!iter->wrap_count && iter->block == iter->start_block)
@@ -655,14 +648,15 @@ next_block:
 static void msc_buffer_clear_hw_header(struct msc *msc)
 {
 	struct msc_window *win;
+	struct scatterlist *sg;
 
 	list_for_each_entry(win, &msc->win_list, entry) {
 		unsigned int blk;
 		size_t hw_sz = sizeof(struct msc_block_desc) -
 			offsetof(struct msc_block_desc, hw_tag);
 
-		for (blk = 0; blk < win->nr_segs; blk++) {
-			struct msc_block_desc *bdesc = msc_win_block(win, blk);
+		for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
+			struct msc_block_desc *bdesc = sg_virt(sg);
 
 			memset(&bdesc->hw_tag, 0, hw_sz);
 		}
@@ -1005,10 +999,9 @@ static int __msc_buffer_win_alloc(struct msc_window *win,
 	return nr_segs;
 
 err_nomem:
-	for (i--; i >= 0; i--)
+	for_each_sg(win->sgt->sgl, sg_ptr, i, ret)
 		dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE,
-				  msc_win_block(win, i),
-				  msc_win_baddr(win, i));
+				  sg_virt(sg_ptr), sg_dma_address(sg_ptr));
 
 	sg_free_table(win->sgt);
 
@@ -1018,20 +1011,26 @@ err_nomem:
 #ifdef CONFIG_X86
 static void msc_buffer_set_uc(struct msc_window *win, unsigned int nr_segs)
 {
+	struct scatterlist *sg_ptr;
 	int i;
 
-	for (i = 0; i < nr_segs; i++)
+	for_each_sg(win->sgt->sgl, sg_ptr, nr_segs, i) {
 		/* Set the page as uncached */
-		set_memory_uc((unsigned long)msc_win_block(win, i), 1);
+		set_memory_uc((unsigned long)sg_virt(sg_ptr),
+			      PFN_DOWN(sg_ptr->length));
+	}
 }
 
 static void msc_buffer_set_wb(struct msc_window *win)
 {
+	struct scatterlist *sg_ptr;
 	int i;
 
-	for (i = 0; i < win->nr_segs; i++)
+	for_each_sg(win->sgt->sgl, sg_ptr, win->nr_segs, i) {
 		/* Reset the page to write-back */
-		set_memory_wb((unsigned long)msc_win_block(win, i), 1);
+		set_memory_wb((unsigned long)sg_virt(sg_ptr),
+			      PFN_DOWN(sg_ptr->length));
+	}
 }
 #else /* !X86 */
 static inline void
@@ -1057,13 +1056,6 @@ static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks)
 	if (!nr_blocks)
 		return 0;
 
-	/*
-	 * This limitation hold as long as we need random access to the
-	 * block. When that changes, this can go away.
-	 */
-	if (nr_blocks > SG_MAX_SINGLE_ALLOC)
-		return -EINVAL;
-
 	win = kzalloc(sizeof(*win), GFP_KERNEL);
 	if (!win)
 		return -ENOMEM;
@@ -1096,8 +1088,8 @@ static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks)
 	win->nr_blocks = nr_blocks;
 
 	if (list_empty(&msc->win_list)) {
-		msc->base = msc_win_block(win, 0);
-		msc->base_addr = msc_win_baddr(win, 0);
+		msc->base = msc_win_base(win);
+		msc->base_addr = msc_win_base_dma(win);
 		msc->cur_win = win;
 	}
 
@@ -1114,14 +1106,15 @@ err_nomem:
 
 static void __msc_buffer_win_free(struct msc *msc, struct msc_window *win)
 {
+	struct scatterlist *sg;
 	int i;
 
-	for (i = 0; i < win->nr_segs; i++) {
-		struct page *page = sg_page(&win->sgt->sgl[i]);
+	for_each_sg(win->sgt->sgl, sg, win->nr_segs, i) {
+		struct page *page = sg_page(sg);
 
 		page->mapping = NULL;
 		dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE,
-				  msc_win_block(win, i), msc_win_baddr(win, i));
+				  sg_virt(sg), sg_dma_address(sg));
 	}
 	sg_free_table(win->sgt);
 }
@@ -1167,6 +1160,7 @@ static void msc_buffer_relink(struct msc *msc)
 
 	/* call with msc::mutex locked */
 	list_for_each_entry(win, &msc->win_list, entry) {
+		struct scatterlist *sg;
 		unsigned int blk;
 		u32 sw_tag = 0;
 
@@ -1182,12 +1176,12 @@ static void msc_buffer_relink(struct msc *msc)
 			next_win = list_next_entry(win, entry);
 		}
 
-		for (blk = 0; blk < win->nr_segs; blk++) {
-			struct msc_block_desc *bdesc = msc_win_block(win, blk);
+		for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
+			struct msc_block_desc *bdesc = sg_virt(sg);
 
 			memset(bdesc, 0, sizeof(*bdesc));
 
-			bdesc->next_win = msc_win_bpfn(next_win, 0);
+			bdesc->next_win = msc_win_base_pfn(next_win);
 
 			/*
 			 * Similarly to last window, last block should point
@@ -1195,13 +1189,15 @@ static void msc_buffer_relink(struct msc *msc)
 			 */
 			if (blk == win->nr_segs - 1) {
 				sw_tag |= MSC_SW_TAG_LASTBLK;
-				bdesc->next_blk = msc_win_bpfn(win, 0);
+				bdesc->next_blk = msc_win_base_pfn(win);
 			} else {
-				bdesc->next_blk = msc_win_bpfn(win, blk + 1);
+				dma_addr_t addr = sg_dma_address(sg_next(sg));
+
+				bdesc->next_blk = PFN_DOWN(addr);
 			}
 
 			bdesc->sw_tag = sw_tag;
-			bdesc->block_sz = msc_win_actual_bsz(win, blk) / 64;
+			bdesc->block_sz = sg->length / 64;
 		}
 	}
 
@@ -1360,6 +1356,7 @@ static int msc_buffer_free_unless_used(struct msc *msc)
 static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff)
 {
 	struct msc_window *win;
+	struct scatterlist *sg;
 	unsigned int blk;
 
 	if (msc->mode == MSC_MODE_SINGLE)
@@ -1374,9 +1371,9 @@ static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff)
 found:
 	pgoff -= win->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));
+	for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
+		struct page *page = sg_page(sg);
+		size_t pgsz = PFN_DOWN(sg->length);
 
 		if (pgoff < pgsz)
 			return page + pgoff;
@@ -1680,8 +1677,8 @@ static void msc_win_switch(struct msc *msc)
 	else
 		msc->cur_win = list_next_entry(msc->cur_win, entry);
 
-	msc->base = msc_win_block(msc->cur_win, 0);
-	msc->base_addr = msc_win_baddr(msc->cur_win, 0);
+	msc->base = msc_win_base(msc->cur_win);
+	msc->base_addr = msc_win_base_dma(msc->cur_win);
 
 	intel_th_trace_switch(msc->thdev);
 }