PM: hibernate: Move to crypto APIs for LZO compression

Currently for hibernation, LZO is the only compression algorithm
available and uses the existing LZO library calls. However, there
is no flexibility to switch to other algorithms which provides better
results. The main idea is that different compression algorithms have
different characteristics and hibernation may benefit when it uses
alternate algorithms.

By moving to crypto based APIs, it lays a foundation to use other
compression algorithms for hibernation. There are no functional changes
introduced by this approach.

Signed-off-by: Nikhil V <quic_nprakash@quicinc.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 75 insertions, 26 deletions

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 35c62f91c13b..6513035f2f7f 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -23,7 +23,6 @@
 #include <linux/swapops.h>
 #include <linux/pm.h>
 #include <linux/slab.h>
-#include <linux/lzo.h>
 #include <linux/vmalloc.h>
 #include <linux/cpumask.h>
 #include <linux/atomic.h>
@@ -339,6 +338,13 @@ static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 	return error;
 }
 
+/*
+ * Hold the swsusp_header flag. This is used in software_resume() in
+ * 'kernel/power/hibernate' to check if the image is compressed and query
+ * for the compression algorithm support(if so).
+ */
+unsigned int swsusp_header_flags;
+
 /**
  *	swsusp_swap_check - check if the resume device is a swap device
  *	and get its index (if so)
@@ -514,6 +520,12 @@ static int swap_writer_finish(struct swap_map_handle *handle,
 	return error;
 }
 
+/*
+ * Bytes we need for compressed data in worst case. We assume(limitation)
+ * this is the worst of all the compression algorithms.
+ */
+#define bytes_worst_compress(x) ((x) + ((x) / 16) + 64 + 3 + 2)
+
 /* We need to remember how much compressed data we need to read. */
 #define CMP_HEADER	sizeof(size_t)
 
@@ -522,7 +534,7 @@ static int swap_writer_finish(struct swap_map_handle *handle,
 #define UNC_SIZE	(UNC_PAGES * PAGE_SIZE)
 
 /* Number of pages we need for compressed data (worst case). */
-#define CMP_PAGES	DIV_ROUND_UP(lzo1x_worst_compress(UNC_SIZE) + \
+#define CMP_PAGES	DIV_ROUND_UP(bytes_worst_compress(UNC_SIZE) + \
 				CMP_HEADER, PAGE_SIZE)
 #define CMP_SIZE	(CMP_PAGES * PAGE_SIZE)
 
@@ -533,7 +545,6 @@ static int swap_writer_finish(struct swap_map_handle *handle,
 #define CMP_MIN_RD_PAGES	1024
 #define CMP_MAX_RD_PAGES	8192
 
-
 /**
  *	save_image - save the suspend image data
  */
@@ -629,6 +640,7 @@ static int crc32_threadfn(void *data)
  */
 struct cmp_data {
 	struct task_struct *thr;                  /* thread */
+	struct crypto_comp *cc;                   /* crypto compressor stream */
 	atomic_t ready;                           /* ready to start flag */
 	atomic_t stop;                            /* ready to stop flag */
 	int ret;                                  /* return code */
@@ -638,15 +650,18 @@ struct cmp_data {
 	size_t cmp_len;                           /* compressed length */
 	unsigned char unc[UNC_SIZE];              /* uncompressed buffer */
 	unsigned char cmp[CMP_SIZE];              /* compressed buffer */
-	unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 };
 
+/* Indicates the image size after compression */
+static atomic_t compressed_size = ATOMIC_INIT(0);
+
 /*
  * Compression function that runs in its own thread.
  */
 static int compress_threadfn(void *data)
 {
 	struct cmp_data *d = data;
+	unsigned int cmp_len = 0;
 
 	while (1) {
 		wait_event(d->go, atomic_read_acquire(&d->ready) ||
@@ -660,9 +675,13 @@ static int compress_threadfn(void *data)
 		}
 		atomic_set(&d->ready, 0);
 
-		d->ret = lzo1x_1_compress(d->unc, d->unc_len,
-					  d->cmp + CMP_HEADER, &d->cmp_len,
-		                          d->wrk);
+		cmp_len = CMP_SIZE - CMP_HEADER;
+		d->ret = crypto_comp_compress(d->cc, d->unc, d->unc_len,
+					      d->cmp + CMP_HEADER,
+					      &cmp_len);
+		d->cmp_len = cmp_len;
+
+		atomic_set(&compressed_size, atomic_read(&compressed_size) + d->cmp_len);
 		atomic_set_release(&d->stop, 1);
 		wake_up(&d->done);
 	}
@@ -694,6 +713,8 @@ static int save_compressed_image(struct swap_map_handle *handle,
 
 	hib_init_batch(&hb);
 
+	atomic_set(&compressed_size, 0);
+
 	/*
 	 * We'll limit the number of threads for compression to limit memory
 	 * footprint.
@@ -703,14 +724,14 @@ static int save_compressed_image(struct swap_map_handle *handle,
 
 	page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
 	if (!page) {
-		pr_err("Failed to allocate compression page\n");
+		pr_err("Failed to allocate %s page\n", hib_comp_algo);
 		ret = -ENOMEM;
 		goto out_clean;
 	}
 
 	data = vzalloc(array_size(nr_threads, sizeof(*data)));
 	if (!data) {
-		pr_err("Failed to allocate compression data\n");
+		pr_err("Failed to allocate %s data\n", hib_comp_algo);
 		ret = -ENOMEM;
 		goto out_clean;
 	}
@@ -729,6 +750,13 @@ static int save_compressed_image(struct swap_map_handle *handle,
 		init_waitqueue_head(&data[thr].go);
 		init_waitqueue_head(&data[thr].done);
 
+		data[thr].cc = crypto_alloc_comp(hib_comp_algo, 0, 0);
+		if (IS_ERR_OR_NULL(data[thr].cc)) {
+			pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
+			ret = -EFAULT;
+			goto out_clean;
+		}
+
 		data[thr].thr = kthread_run(compress_threadfn,
 		                            &data[thr],
 		                            "image_compress/%u", thr);
@@ -767,7 +795,7 @@ static int save_compressed_image(struct swap_map_handle *handle,
 	 */
 	handle->reqd_free_pages = reqd_free_pages();
 
-	pr_info("Using %u thread(s) for compression\n", nr_threads);
+	pr_info("Using %u thread(s) for %s compression\n", nr_threads, hib_comp_algo);
 	pr_info("Compressing and saving image data (%u pages)...\n",
 		nr_to_write);
 	m = nr_to_write / 10;
@@ -817,14 +845,14 @@ static int save_compressed_image(struct swap_map_handle *handle,
 			ret = data[thr].ret;
 
 			if (ret < 0) {
-				pr_err("compression failed\n");
+				pr_err("%s compression failed\n", hib_comp_algo);
 				goto out_finish;
 			}
 
 			if (unlikely(!data[thr].cmp_len ||
 			             data[thr].cmp_len >
-			             lzo1x_worst_compress(data[thr].unc_len))) {
-				pr_err("Invalid compressed length\n");
+				     bytes_worst_compress(data[thr].unc_len))) {
+				pr_err("Invalid %s compressed length\n", hib_comp_algo);
 				ret = -1;
 				goto out_finish;
 			}
@@ -862,6 +890,9 @@ out_finish:
 	if (!ret)
 		pr_info("Image saving done\n");
 	swsusp_show_speed(start, stop, nr_to_write, "Wrote");
+	pr_info("Image size after compression: %d kbytes\n",
+		(atomic_read(&compressed_size) / 1024));
+
 out_clean:
 	hib_finish_batch(&hb);
 	if (crc) {
@@ -870,9 +901,12 @@ out_clean:
 		kfree(crc);
 	}
 	if (data) {
-		for (thr = 0; thr < nr_threads; thr++)
+		for (thr = 0; thr < nr_threads; thr++) {
 			if (data[thr].thr)
 				kthread_stop(data[thr].thr);
+			if (data[thr].cc)
+				crypto_free_comp(data[thr].cc);
+		}
 		vfree(data);
 	}
 	if (page) free_page((unsigned long)page);
@@ -1113,6 +1147,7 @@ static int load_image(struct swap_map_handle *handle,
  */
 struct dec_data {
 	struct task_struct *thr;                  /* thread */
+	struct crypto_comp *cc;                   /* crypto compressor stream */
 	atomic_t ready;                           /* ready to start flag */
 	atomic_t stop;                            /* ready to stop flag */
 	int ret;                                  /* return code */
@@ -1130,6 +1165,7 @@ struct dec_data {
 static int decompress_threadfn(void *data)
 {
 	struct dec_data *d = data;
+	unsigned int unc_len = 0;
 
 	while (1) {
 		wait_event(d->go, atomic_read_acquire(&d->ready) ||
@@ -1143,9 +1179,11 @@ static int decompress_threadfn(void *data)
 		}
 		atomic_set(&d->ready, 0);
 
-		d->unc_len = UNC_SIZE;
-		d->ret = lzo1x_decompress_safe(d->cmp + CMP_HEADER, d->cmp_len,
-					       d->unc, &d->unc_len);
+		unc_len = UNC_SIZE;
+		d->ret = crypto_comp_decompress(d->cc, d->cmp + CMP_HEADER, d->cmp_len,
+						d->unc, &unc_len);
+		d->unc_len = unc_len;
+
 		if (clean_pages_on_decompress)
 			flush_icache_range((unsigned long)d->unc,
 					   (unsigned long)d->unc + d->unc_len);
@@ -1193,14 +1231,14 @@ static int load_compressed_image(struct swap_map_handle *handle,
 
 	page = vmalloc(array_size(CMP_MAX_RD_PAGES, sizeof(*page)));
 	if (!page) {
-		pr_err("Failed to allocate compression page\n");
+		pr_err("Failed to allocate %s page\n", hib_comp_algo);
 		ret = -ENOMEM;
 		goto out_clean;
 	}
 
 	data = vzalloc(array_size(nr_threads, sizeof(*data)));
 	if (!data) {
-		pr_err("Failed to allocate compression data\n");
+		pr_err("Failed to allocate %s data\n", hib_comp_algo);
 		ret = -ENOMEM;
 		goto out_clean;
 	}
@@ -1221,6 +1259,13 @@ static int load_compressed_image(struct swap_map_handle *handle,
 		init_waitqueue_head(&data[thr].go);
 		init_waitqueue_head(&data[thr].done);
 
+		data[thr].cc = crypto_alloc_comp(hib_comp_algo, 0, 0);
+		if (IS_ERR_OR_NULL(data[thr].cc)) {
+			pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
+			ret = -EFAULT;
+			goto out_clean;
+		}
+
 		data[thr].thr = kthread_run(decompress_threadfn,
 		                            &data[thr],
 		                            "image_decompress/%u", thr);
@@ -1273,7 +1318,7 @@ static int load_compressed_image(struct swap_map_handle *handle,
 		if (!page[i]) {
 			if (i < CMP_PAGES) {
 				ring_size = i;
-				pr_err("Failed to allocate compression pages\n");
+				pr_err("Failed to allocate %s pages\n", hib_comp_algo);
 				ret = -ENOMEM;
 				goto out_clean;
 			} else {
@@ -1283,7 +1328,7 @@ static int load_compressed_image(struct swap_map_handle *handle,
 	}
 	want = ring_size = i;
 
-	pr_info("Using %u thread(s) for decompression\n", nr_threads);
+	pr_info("Using %u thread(s) for %s decompression\n", nr_threads, hib_comp_algo);
 	pr_info("Loading and decompressing image data (%u pages)...\n",
 		nr_to_read);
 	m = nr_to_read / 10;
@@ -1344,8 +1389,8 @@ static int load_compressed_image(struct swap_map_handle *handle,
 			data[thr].cmp_len = *(size_t *)page[pg];
 			if (unlikely(!data[thr].cmp_len ||
 			             data[thr].cmp_len >
-					lzo1x_worst_compress(UNC_SIZE))) {
-				pr_err("Invalid compressed length\n");
+					bytes_worst_compress(UNC_SIZE))) {
+				pr_err("Invalid %s compressed length\n", hib_comp_algo);
 				ret = -1;
 				goto out_finish;
 			}
@@ -1396,14 +1441,14 @@ static int load_compressed_image(struct swap_map_handle *handle,
 			ret = data[thr].ret;
 
 			if (ret < 0) {
-				pr_err("decompression failed\n");
+				pr_err("%s decompression failed\n", hib_comp_algo);
 				goto out_finish;
 			}
 
 			if (unlikely(!data[thr].unc_len ||
 				data[thr].unc_len > UNC_SIZE ||
 				data[thr].unc_len & (PAGE_SIZE - 1))) {
-				pr_err("Invalid uncompressed length\n");
+				pr_err("Invalid %s uncompressed length\n", hib_comp_algo);
 				ret = -1;
 				goto out_finish;
 			}
@@ -1464,9 +1509,12 @@ out_clean:
 		kfree(crc);
 	}
 	if (data) {
-		for (thr = 0; thr < nr_threads; thr++)
+		for (thr = 0; thr < nr_threads; thr++) {
 			if (data[thr].thr)
 				kthread_stop(data[thr].thr);
+			if (data[thr].cc)
+				crypto_free_comp(data[thr].cc);
+		}
 		vfree(data);
 	}
 	vfree(page);
@@ -1535,6 +1583,7 @@ int swsusp_check(bool exclusive)
 
 		if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
 			memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
+			swsusp_header_flags = swsusp_header->flags;
 			/* Reset swap signature now */
 			error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
 						swsusp_resume_block,