1 files changed, 299 insertions, 108 deletions

diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c
index ba7aaf421f36..81bb54fa3ce8 100644
--- a/drivers/hwtracing/intel_th/msu.c
+++ b/drivers/hwtracing/intel_th/msu.c
@@ -29,28 +29,18 @@
 #define msc_dev(x) (&(x)->thdev->dev)
 
 /**
- * struct msc_block - multiblock mode block descriptor
- * @bdesc:	pointer to hardware descriptor (beginning of the block)
- * @addr:	physical address of the block
- */
-struct msc_block {
-	struct msc_block_desc	*bdesc;
-	dma_addr_t		addr;
-};
-
-/**
  * struct msc_window - multiblock mode window descriptor
  * @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
- * @block:	array of block descriptors
+ * @sgt:	array of block descriptors
  */
 struct msc_window {
 	struct list_head	entry;
 	unsigned long		pgoff;
 	unsigned int		nr_blocks;
 	struct msc		*msc;
-	struct msc_block	block[0];
+	struct sg_table		sgt;
 };
 
 /**
@@ -84,6 +74,8 @@ struct msc_iter {
  * @reg_base:		register window base address
  * @thdev:		intel_th_device pointer
  * @win_list:		list of windows in multiblock mode
+ * @single_sgt:		single mode buffer
+ * @cur_win:		current window
  * @nr_pages:		total number of pages allocated for this buffer
  * @single_sz:		amount of data in single mode
  * @single_wrap:	single mode wrap occurred
@@ -101,9 +93,12 @@ struct msc_iter {
  */
 struct msc {
 	void __iomem		*reg_base;
+	void __iomem		*msu_base;
 	struct intel_th_device	*thdev;
 
 	struct list_head	win_list;
+	struct sg_table		single_sgt;
+	struct msc_window	*cur_win;
 	unsigned long		nr_pages;
 	unsigned long		single_sz;
 	unsigned int		single_wrap : 1;
@@ -120,7 +115,8 @@ struct msc {
 
 	/* config */
 	unsigned int		enabled : 1,
-				wrap	: 1;
+				wrap	: 1,
+				do_irq	: 1;
 	unsigned int		mode;
 	unsigned int		burst_len;
 	unsigned int		index;
@@ -139,6 +135,49 @@ 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)
+{
+	return sg_virt(&win->sgt.sgl[block]);
+}
+
+static inline dma_addr_t
+msc_win_baddr(struct msc_window *win, unsigned int block)
+{
+	return sg_dma_address(&win->sgt.sgl[block]);
+}
+
+static inline unsigned long
+msc_win_bpfn(struct msc_window *win, unsigned int block)
+{
+	return msc_win_baddr(win, block) >> PAGE_SHIFT;
+}
+
+/**
+ * msc_is_last_win() - check if a window is the last one for a given MSC
+ * @win:	window
+ * Return:	true if @win is the last window in MSC's multiblock buffer
+ */
+static inline bool msc_is_last_win(struct msc_window *win)
+{
+	return win->entry.next == &win->msc->win_list;
+}
+
+/**
+ * msc_next_window() - return next window in the multiblock buffer
+ * @win:	current window
+ *
+ * Return:	window following the current one
+ */
+static struct msc_window *msc_next_window(struct msc_window *win)
+{
+	if (msc_is_last_win(win))
+		return list_first_entry(&win->msc->win_list, struct msc_window,
+					entry);
+
+	return list_next_entry(win, entry);
+}
+
 /**
  * msc_oldest_window() - locate the window with oldest data
  * @msc:	MSC device
@@ -150,9 +189,7 @@ static inline bool msc_block_is_empty(struct msc_block_desc *bdesc)
  */
 static struct msc_window *msc_oldest_window(struct msc *msc)
 {
-	struct msc_window *win;
-	u32 reg = ioread32(msc->reg_base + REG_MSU_MSC0NWSA);
-	unsigned long win_addr = (unsigned long)reg << PAGE_SHIFT;
+	struct msc_window *win, *next = msc_next_window(msc->cur_win);
 	unsigned int found = 0;
 
 	if (list_empty(&msc->win_list))
@@ -164,18 +201,18 @@ static struct msc_window *msc_oldest_window(struct msc *msc)
 	 * something like 2, in which case we're good
 	 */
 	list_for_each_entry(win, &msc->win_list, entry) {
-		if (win->block[0].addr == win_addr)
+		if (win == next)
 			found++;
 
 		/* skip the empty ones */
-		if (msc_block_is_empty(win->block[0].bdesc))
+		if (msc_block_is_empty(msc_win_block(win, 0)))
 			continue;
 
 		if (found)
 			return win;
 	}
 
-	return list_entry(msc->win_list.next, struct msc_window, entry);
+	return list_first_entry(&msc->win_list, struct msc_window, entry);
 }
 
 /**
@@ -187,7 +224,7 @@ static struct msc_window *msc_oldest_window(struct msc *msc)
 static unsigned int msc_win_oldest_block(struct msc_window *win)
 {
 	unsigned int blk;
-	struct msc_block_desc *bdesc = win->block[0].bdesc;
+	struct msc_block_desc *bdesc = msc_win_block(win, 0);
 
 	/* without wrapping, first block is the oldest */
 	if (!msc_block_wrapped(bdesc))
@@ -198,7 +235,7 @@ static unsigned int msc_win_oldest_block(struct msc_window *win)
 	 * oldest data for this window.
 	 */
 	for (blk = 0; blk < win->nr_blocks; blk++) {
-		bdesc = win->block[blk].bdesc;
+		bdesc = msc_win_block(win, blk);
 
 		if (msc_block_last_written(bdesc))
 			return blk;
@@ -207,34 +244,9 @@ static unsigned int msc_win_oldest_block(struct msc_window *win)
 	return 0;
 }
 
-/**
- * msc_is_last_win() - check if a window is the last one for a given MSC
- * @win:	window
- * Return:	true if @win is the last window in MSC's multiblock buffer
- */
-static inline bool msc_is_last_win(struct msc_window *win)
-{
-	return win->entry.next == &win->msc->win_list;
-}
-
-/**
- * msc_next_window() - return next window in the multiblock buffer
- * @win:	current window
- *
- * Return:	window following the current one
- */
-static struct msc_window *msc_next_window(struct msc_window *win)
-{
-	if (msc_is_last_win(win))
-		return list_entry(win->msc->win_list.next, struct msc_window,
-				  entry);
-
-	return list_entry(win->entry.next, struct msc_window, entry);
-}
-
 static struct msc_block_desc *msc_iter_bdesc(struct msc_iter *iter)
 {
-	return iter->win->block[iter->block].bdesc;
+	return msc_win_block(iter->win, iter->block);
 }
 
 static void msc_iter_init(struct msc_iter *iter)
@@ -467,13 +479,47 @@ static void msc_buffer_clear_hw_header(struct msc *msc)
 			offsetof(struct msc_block_desc, hw_tag);
 
 		for (blk = 0; blk < win->nr_blocks; blk++) {
-			struct msc_block_desc *bdesc = win->block[blk].bdesc;
+			struct msc_block_desc *bdesc = msc_win_block(win, blk);
 
 			memset(&bdesc->hw_tag, 0, hw_sz);
 		}
 	}
 }
 
+static int intel_th_msu_init(struct msc *msc)
+{
+	u32 mintctl, msusts;
+
+	if (!msc->do_irq)
+		return 0;
+
+	mintctl = ioread32(msc->msu_base + REG_MSU_MINTCTL);
+	mintctl |= msc->index ? M1BLIE : M0BLIE;
+	iowrite32(mintctl, msc->msu_base + REG_MSU_MINTCTL);
+	if (mintctl != ioread32(msc->msu_base + REG_MSU_MINTCTL)) {
+		dev_info(msc_dev(msc), "MINTCTL ignores writes: no usable interrupts\n");
+		msc->do_irq = 0;
+		return 0;
+	}
+
+	msusts = ioread32(msc->msu_base + REG_MSU_MSUSTS);
+	iowrite32(msusts, msc->msu_base + REG_MSU_MSUSTS);
+
+	return 0;
+}
+
+static void intel_th_msu_deinit(struct msc *msc)
+{
+	u32 mintctl;
+
+	if (!msc->do_irq)
+		return;
+
+	mintctl = ioread32(msc->msu_base + REG_MSU_MINTCTL);
+	mintctl &= msc->index ? ~M1BLIE : ~M0BLIE;
+	iowrite32(mintctl, msc->msu_base + REG_MSU_MINTCTL);
+}
+
 /**
  * msc_configure() - set up MSC hardware
  * @msc:	the MSC device to configure
@@ -531,23 +577,14 @@ static int msc_configure(struct msc *msc)
  */
 static void msc_disable(struct msc *msc)
 {
-	unsigned long count;
 	u32 reg;
 
 	lockdep_assert_held(&msc->buf_mutex);
 
 	intel_th_trace_disable(msc->thdev);
 
-	for (reg = 0, count = MSC_PLE_WAITLOOP_DEPTH;
-	     count && !(reg & MSCSTS_PLE); count--) {
-		reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
-		cpu_relax();
-	}
-
-	if (!count)
-		dev_dbg(msc_dev(msc), "timeout waiting for MSC0 PLE\n");
-
 	if (msc->mode == MSC_MODE_SINGLE) {
+		reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
 		msc->single_wrap = !!(reg & MSCSTS_WRAPSTAT);
 
 		reg = ioread32(msc->reg_base + REG_MSU_MSC0MWP);
@@ -617,22 +654,45 @@ static void intel_th_msc_deactivate(struct intel_th_device *thdev)
  */
 static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size)
 {
+	unsigned long nr_pages = size >> PAGE_SHIFT;
 	unsigned int order = get_order(size);
 	struct page *page;
+	int ret;
 
 	if (!size)
 		return 0;
 
+	ret = sg_alloc_table(&msc->single_sgt, 1, GFP_KERNEL);
+	if (ret)
+		goto err_out;
+
+	ret = -ENOMEM;
 	page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
 	if (!page)
-		return -ENOMEM;
+		goto err_free_sgt;
 
 	split_page(page, order);
-	msc->nr_pages = size >> PAGE_SHIFT;
+	sg_set_buf(msc->single_sgt.sgl, page_address(page), size);
+
+	ret = dma_map_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl, 1,
+			 DMA_FROM_DEVICE);
+	if (ret < 0)
+		goto err_free_pages;
+
+	msc->nr_pages = nr_pages;
 	msc->base = page_address(page);
-	msc->base_addr = page_to_phys(page);
+	msc->base_addr = sg_dma_address(msc->single_sgt.sgl);
 
 	return 0;
+
+err_free_pages:
+	__free_pages(page, order);
+
+err_free_sgt:
+	sg_free_table(&msc->single_sgt);
+
+err_out:
+	return ret;
 }
 
 /**
@@ -643,6 +703,10 @@ static void msc_buffer_contig_free(struct msc *msc)
 {
 	unsigned long off;
 
+	dma_unmap_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl,
+		     1, DMA_FROM_DEVICE);
+	sg_free_table(&msc->single_sgt);
+
 	for (off = 0; off < msc->nr_pages << PAGE_SHIFT; off += PAGE_SIZE) {
 		struct page *page = virt_to_page(msc->base + off);
 
@@ -669,6 +733,40 @@ static struct page *msc_buffer_contig_get_page(struct msc *msc,
 	return virt_to_page(msc->base + (pgoff << PAGE_SHIFT));
 }
 
+static int __msc_buffer_win_alloc(struct msc_window *win,
+				  unsigned int nr_blocks)
+{
+	struct scatterlist *sg_ptr;
+	void *block;
+	int i, ret;
+
+	ret = sg_alloc_table(&win->sgt, nr_blocks, GFP_KERNEL);
+	if (ret)
+		return -ENOMEM;
+
+	for_each_sg(win->sgt.sgl, sg_ptr, nr_blocks, i) {
+		block = dma_alloc_coherent(msc_dev(win->msc)->parent->parent,
+					  PAGE_SIZE, &sg_dma_address(sg_ptr),
+					  GFP_KERNEL);
+		if (!block)
+			goto err_nomem;
+
+		sg_set_buf(sg_ptr, block, PAGE_SIZE);
+	}
+
+	return nr_blocks;
+
+err_nomem:
+	for (i--; i >= 0; i--)
+		dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE,
+				  msc_win_block(win, i),
+				  msc_win_baddr(win, i));
+
+	sg_free_table(&win->sgt);
+
+	return -ENOMEM;
+}
+
 /**
  * msc_buffer_win_alloc() - alloc a window for a multiblock mode
  * @msc:	MSC device
@@ -682,44 +780,49 @@ static struct page *msc_buffer_contig_get_page(struct msc *msc,
 static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks)
 {
 	struct msc_window *win;
-	unsigned long size = PAGE_SIZE;
-	int i, ret = -ENOMEM;
+	int ret = -ENOMEM, i;
 
 	if (!nr_blocks)
 		return 0;
 
-	win = kzalloc(offsetof(struct msc_window, block[nr_blocks]),
-		      GFP_KERNEL);
+	/*
+	 * 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;
 
+	win->msc = msc;
+
 	if (!list_empty(&msc->win_list)) {
-		struct msc_window *prev = list_entry(msc->win_list.prev,
-						     struct msc_window, entry);
+		struct msc_window *prev = list_last_entry(&msc->win_list,
+							  struct msc_window,
+							  entry);
 
+		/* This works as long as blocks are page-sized */
 		win->pgoff = prev->pgoff + prev->nr_blocks;
 	}
 
-	for (i = 0; i < nr_blocks; i++) {
-		win->block[i].bdesc =
-			dma_alloc_coherent(msc_dev(msc)->parent->parent, size,
-					   &win->block[i].addr, GFP_KERNEL);
-
-		if (!win->block[i].bdesc)
-			goto err_nomem;
+	ret = __msc_buffer_win_alloc(win, nr_blocks);
+	if (ret < 0)
+		goto err_nomem;
 
 #ifdef CONFIG_X86
+	for (i = 0; i < ret; i++)
 		/* Set the page as uncached */
-		set_memory_uc((unsigned long)win->block[i].bdesc, 1);
+		set_memory_uc((unsigned long)msc_win_block(win, i), 1);
 #endif
-	}
 
-	win->msc = msc;
-	win->nr_blocks = nr_blocks;
+	win->nr_blocks = ret;
 
 	if (list_empty(&msc->win_list)) {
-		msc->base = win->block[0].bdesc;
-		msc->base_addr = win->block[0].addr;
+		msc->base = msc_win_block(win, 0);
+		msc->base_addr = msc_win_baddr(win, 0);
+		msc->cur_win = win;
 	}
 
 	list_add_tail(&win->entry, &msc->win_list);
@@ -728,19 +831,25 @@ static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks)
 	return 0;
 
 err_nomem:
-	for (i--; i >= 0; i--) {
-#ifdef CONFIG_X86
-		/* Reset the page to write-back before releasing */
-		set_memory_wb((unsigned long)win->block[i].bdesc, 1);
-#endif
-		dma_free_coherent(msc_dev(msc)->parent->parent, size,
-				  win->block[i].bdesc, win->block[i].addr);
-	}
 	kfree(win);
 
 	return ret;
 }
 
+static void __msc_buffer_win_free(struct msc *msc, struct msc_window *win)
+{
+	int i;
+
+	for (i = 0; i < win->nr_blocks; i++) {
+		struct page *page = sg_page(&win->sgt.sgl[i]);
+
+		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_free_table(&win->sgt);
+}
+
 /**
  * msc_buffer_win_free() - free a window from MSC's window list
  * @msc:	MSC device
@@ -761,17 +870,13 @@ static void msc_buffer_win_free(struct msc *msc, struct msc_window *win)
 		msc->base_addr = 0;
 	}
 
-	for (i = 0; i < win->nr_blocks; i++) {
-		struct page *page = virt_to_page(win->block[i].bdesc);
-
-		page->mapping = NULL;
 #ifdef CONFIG_X86
-		/* Reset the page to write-back before releasing */
-		set_memory_wb((unsigned long)win->block[i].bdesc, 1);
+	for (i = 0; i < win->nr_blocks; i++)
+		/* Reset the page to write-back */
+		set_memory_wb((unsigned long)msc_win_block(win, i), 1);
 #endif
-		dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE,
-				  win->block[i].bdesc, win->block[i].addr);
-	}
+
+	__msc_buffer_win_free(msc, win);
 
 	kfree(win);
 }
@@ -798,19 +903,18 @@ static void msc_buffer_relink(struct msc *msc)
 		 */
 		if (msc_is_last_win(win)) {
 			sw_tag |= MSC_SW_TAG_LASTWIN;
-			next_win = list_entry(msc->win_list.next,
-					      struct msc_window, entry);
+			next_win = list_first_entry(&msc->win_list,
+						    struct msc_window, entry);
 		} else {
-			next_win = list_entry(win->entry.next,
-					      struct msc_window, entry);
+			next_win = list_next_entry(win, entry);
 		}
 
 		for (blk = 0; blk < win->nr_blocks; blk++) {
-			struct msc_block_desc *bdesc = win->block[blk].bdesc;
+			struct msc_block_desc *bdesc = msc_win_block(win, blk);
 
 			memset(bdesc, 0, sizeof(*bdesc));
 
-			bdesc->next_win = next_win->block[0].addr >> PAGE_SHIFT;
+			bdesc->next_win = msc_win_bpfn(next_win, 0);
 
 			/*
 			 * Similarly to last window, last block should point
@@ -818,11 +922,9 @@ static void msc_buffer_relink(struct msc *msc)
 			 */
 			if (blk == win->nr_blocks - 1) {
 				sw_tag |= MSC_SW_TAG_LASTBLK;
-				bdesc->next_blk =
-					win->block[0].addr >> PAGE_SHIFT;
+				bdesc->next_blk = msc_win_bpfn(win, 0);
 			} else {
-				bdesc->next_blk =
-					win->block[blk + 1].addr >> PAGE_SHIFT;
+				bdesc->next_blk = msc_win_bpfn(win, blk + 1);
 			}
 
 			bdesc->sw_tag = sw_tag;
@@ -997,7 +1099,7 @@ static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff)
 
 found:
 	pgoff -= win->pgoff;
-	return virt_to_page(win->block[pgoff].bdesc);
+	return sg_page(&win->sgt.sgl[pgoff]);
 }
 
 /**
@@ -1250,6 +1352,22 @@ static const struct file_operations intel_th_msc_fops = {
 	.owner		= THIS_MODULE,
 };
 
+static void intel_th_msc_wait_empty(struct intel_th_device *thdev)
+{
+	struct msc *msc = dev_get_drvdata(&thdev->dev);
+	unsigned long count;
+	u32 reg;
+
+	for (reg = 0, count = MSC_PLE_WAITLOOP_DEPTH;
+	     count && !(reg & MSCSTS_PLE); count--) {
+		reg = __raw_readl(msc->reg_base + REG_MSU_MSC0STS);
+		cpu_relax();
+	}
+
+	if (!count)
+		dev_dbg(msc_dev(msc), "timeout waiting for MSC0 PLE\n");
+}
+
 static int intel_th_msc_init(struct msc *msc)
 {
 	atomic_set(&msc->user_count, -1);
@@ -1266,6 +1384,39 @@ static int intel_th_msc_init(struct msc *msc)
 	return 0;
 }
 
+static void msc_win_switch(struct msc *msc)
+{
+	struct msc_window *last, *first;
+
+	first = list_first_entry(&msc->win_list, struct msc_window, entry);
+	last = list_last_entry(&msc->win_list, struct msc_window, entry);
+
+	if (msc_is_last_win(msc->cur_win))
+		msc->cur_win = first;
+	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);
+
+	intel_th_trace_switch(msc->thdev);
+}
+
+static irqreturn_t intel_th_msc_interrupt(struct intel_th_device *thdev)
+{
+	struct msc *msc = dev_get_drvdata(&thdev->dev);
+	u32 msusts = ioread32(msc->msu_base + REG_MSU_MSUSTS);
+	u32 mask = msc->index ? MSUSTS_MSC1BLAST : MSUSTS_MSC0BLAST;
+
+	if (!(msusts & mask)) {
+		if (msc->enabled)
+			return IRQ_HANDLED;
+		return IRQ_NONE;
+	}
+
+	return IRQ_HANDLED;
+}
+
 static const char * const msc_mode[] = {
 	[MSC_MODE_SINGLE]	= "single",
 	[MSC_MODE_MULTI]	= "multi",
@@ -1440,10 +1591,38 @@ free_win:
 
 static DEVICE_ATTR_RW(nr_pages);
 
+static ssize_t
+win_switch_store(struct device *dev, struct device_attribute *attr,
+		 const char *buf, size_t size)
+{
+	struct msc *msc = dev_get_drvdata(dev);
+	unsigned long val;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &val);
+	if (ret)
+		return ret;
+
+	if (val != 1)
+		return -EINVAL;
+
+	mutex_lock(&msc->buf_mutex);
+	if (msc->mode != MSC_MODE_MULTI)
+		ret = -ENOTSUPP;
+	else
+		msc_win_switch(msc);
+	mutex_unlock(&msc->buf_mutex);
+
+	return ret ? ret : size;
+}
+
+static DEVICE_ATTR_WO(win_switch);
+
 static struct attribute *msc_output_attrs[] = {
 	&dev_attr_wrap.attr,
 	&dev_attr_mode.attr,
 	&dev_attr_nr_pages.attr,
+	&dev_attr_win_switch.attr,
 	NULL,
 };
 
@@ -1471,10 +1650,19 @@ static int intel_th_msc_probe(struct intel_th_device *thdev)
 	if (!msc)
 		return -ENOMEM;
 
+	res = intel_th_device_get_resource(thdev, IORESOURCE_IRQ, 1);
+	if (!res)
+		msc->do_irq = 1;
+
 	msc->index = thdev->id;
 
 	msc->thdev = thdev;
 	msc->reg_base = base + msc->index * 0x100;
+	msc->msu_base = base;
+
+	err = intel_th_msu_init(msc);
+	if (err)
+		return err;
 
 	err = intel_th_msc_init(msc);
 	if (err)
@@ -1491,6 +1679,7 @@ static void intel_th_msc_remove(struct intel_th_device *thdev)
 	int ret;
 
 	intel_th_msc_deactivate(thdev);
+	intel_th_msu_deinit(msc);
 
 	/*
 	 * Buffers should not be used at this point except if the
@@ -1504,6 +1693,8 @@ static void intel_th_msc_remove(struct intel_th_device *thdev)
 static struct intel_th_driver intel_th_msc_driver = {
 	.probe	= intel_th_msc_probe,
 	.remove	= intel_th_msc_remove,
+	.irq		= intel_th_msc_interrupt,
+	.wait_empty	= intel_th_msc_wait_empty,
 	.activate	= intel_th_msc_activate,
 	.deactivate	= intel_th_msc_deactivate,
 	.fops	= &intel_th_msc_fops,