Merge tag 'for-v4.6-rc/omap-fixes-a' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into omap-for-v4.6/fixes

ARM: OMAP2+: first hwmod fix for v4.6-rc

Fix a longstanding bug in the hwmod code that could cause
hardware SYSCONFIG register values to not match the kernel's
idea of what they should be, and that could result in lower
performance during IP block idle entry.

Basic build, boot, and PM test logs are available here:

http://www.pwsan.com/omap/testlogs/omap-hwmod-fixes-a-for-v4.6-rc/20160326231727/

1 files changed, 59 insertions, 52 deletions

diff --git a/mm/page_io.c b/mm/page_io.c
index b995a5ba5e8f..18aac7819cc9 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -56,31 +56,20 @@ void end_swap_bio_write(struct bio *bio)
 		 * Also clear PG_reclaim to avoid rotate_reclaimable_page()
 		 */
 		set_page_dirty(page);
-		printk(KERN_ALERT "Write-error on swap-device (%u:%u:%Lu)\n",
-				imajor(bio->bi_bdev->bd_inode),
-				iminor(bio->bi_bdev->bd_inode),
-				(unsigned long long)bio->bi_iter.bi_sector);
+		pr_alert("Write-error on swap-device (%u:%u:%llu)\n",
+			 imajor(bio->bi_bdev->bd_inode),
+			 iminor(bio->bi_bdev->bd_inode),
+			 (unsigned long long)bio->bi_iter.bi_sector);
 		ClearPageReclaim(page);
 	}
 	end_page_writeback(page);
 	bio_put(bio);
 }
 
-static void end_swap_bio_read(struct bio *bio)
+static void swap_slot_free_notify(struct page *page)
 {
-	struct page *page = bio->bi_io_vec[0].bv_page;
-
-	if (bio->bi_error) {
-		SetPageError(page);
-		ClearPageUptodate(page);
-		printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
-				imajor(bio->bi_bdev->bd_inode),
-				iminor(bio->bi_bdev->bd_inode),
-				(unsigned long long)bio->bi_iter.bi_sector);
-		goto out;
-	}
-
-	SetPageUptodate(page);
+	struct swap_info_struct *sis;
+	struct gendisk *disk;
 
 	/*
 	 * There is no guarantee that the page is in swap cache - the software
@@ -88,42 +77,59 @@ static void end_swap_bio_read(struct bio *bio)
 	 * swapcache page.  So we must check PG_swapcache before proceeding with
 	 * this optimization.
 	 */
-	if (likely(PageSwapCache(page))) {
-		struct swap_info_struct *sis;
+	if (unlikely(!PageSwapCache(page)))
+		return;
 
-		sis = page_swap_info(page);
-		if (sis->flags & SWP_BLKDEV) {
-			/*
-			 * The swap subsystem performs lazy swap slot freeing,
-			 * expecting that the page will be swapped out again.
-			 * So we can avoid an unnecessary write if the page
-			 * isn't redirtied.
-			 * This is good for real swap storage because we can
-			 * reduce unnecessary I/O and enhance wear-leveling
-			 * if an SSD is used as the as swap device.
-			 * But if in-memory swap device (eg zram) is used,
-			 * this causes a duplicated copy between uncompressed
-			 * data in VM-owned memory and compressed data in
-			 * zram-owned memory.  So let's free zram-owned memory
-			 * and make the VM-owned decompressed page *dirty*,
-			 * so the page should be swapped out somewhere again if
-			 * we again wish to reclaim it.
-			 */
-			struct gendisk *disk = sis->bdev->bd_disk;
-			if (disk->fops->swap_slot_free_notify) {
-				swp_entry_t entry;
-				unsigned long offset;
+	sis = page_swap_info(page);
+	if (!(sis->flags & SWP_BLKDEV))
+		return;
 
-				entry.val = page_private(page);
-				offset = swp_offset(entry);
+	/*
+	 * The swap subsystem performs lazy swap slot freeing,
+	 * expecting that the page will be swapped out again.
+	 * So we can avoid an unnecessary write if the page
+	 * isn't redirtied.
+	 * This is good for real swap storage because we can
+	 * reduce unnecessary I/O and enhance wear-leveling
+	 * if an SSD is used as the as swap device.
+	 * But if in-memory swap device (eg zram) is used,
+	 * this causes a duplicated copy between uncompressed
+	 * data in VM-owned memory and compressed data in
+	 * zram-owned memory.  So let's free zram-owned memory
+	 * and make the VM-owned decompressed page *dirty*,
+	 * so the page should be swapped out somewhere again if
+	 * we again wish to reclaim it.
+	 */
+	disk = sis->bdev->bd_disk;
+	if (disk->fops->swap_slot_free_notify) {
+		swp_entry_t entry;
+		unsigned long offset;
 
-				SetPageDirty(page);
-				disk->fops->swap_slot_free_notify(sis->bdev,
-						offset);
-			}
-		}
+		entry.val = page_private(page);
+		offset = swp_offset(entry);
+
+		SetPageDirty(page);
+		disk->fops->swap_slot_free_notify(sis->bdev,
+				offset);
+	}
+}
+
+static void end_swap_bio_read(struct bio *bio)
+{
+	struct page *page = bio->bi_io_vec[0].bv_page;
+
+	if (bio->bi_error) {
+		SetPageError(page);
+		ClearPageUptodate(page);
+		pr_alert("Read-error on swap-device (%u:%u:%llu)\n",
+			 imajor(bio->bi_bdev->bd_inode),
+			 iminor(bio->bi_bdev->bd_inode),
+			 (unsigned long long)bio->bi_iter.bi_sector);
+		goto out;
 	}
 
+	SetPageUptodate(page);
+	swap_slot_free_notify(page);
 out:
 	unlock_page(page);
 	bio_put(bio);
@@ -216,7 +222,7 @@ reprobe:
 out:
 	return ret;
 bad_bmap:
-	printk(KERN_ERR "swapon: swapfile has holes\n");
+	pr_err("swapon: swapfile has holes\n");
 	ret = -EINVAL;
 	goto out;
 }
@@ -290,8 +296,8 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
 			 */
 			set_page_dirty(page);
 			ClearPageReclaim(page);
-			pr_err_ratelimited("Write error on dio swapfile (%Lu)\n",
-				page_file_offset(page));
+			pr_err_ratelimited("Write error on dio swapfile (%llu)\n",
+					   page_file_offset(page));
 		}
 		end_page_writeback(page);
 		return ret;
@@ -347,6 +353,7 @@ int swap_readpage(struct page *page)
 
 	ret = bdev_read_page(sis->bdev, swap_page_sector(page), page);
 	if (!ret) {
+		swap_slot_free_notify(page);
 		count_vm_event(PSWPIN);
 		return 0;
 	}