Merge tag 'for-5.6/drivers-2020-01-27' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:
 "Like the core side, not a lot of changes here, just two main items:

   - Series of patches (via Coly) with fixes for bcache (Coly,
     Christoph)

   - MD pull request from Song"

* tag 'for-5.6/drivers-2020-01-27' of git://git.kernel.dk/linux-block: (31 commits)
  bcache: reap from tail of c->btree_cache in bch_mca_scan()
  bcache: reap c->btree_cache_freeable from the tail in bch_mca_scan()
  bcache: remove member accessed from struct btree
  bcache: print written and keys in trace_bcache_btree_write
  bcache: avoid unnecessary btree nodes flushing in btree_flush_write()
  bcache: add code comments for state->pool in __btree_sort()
  lib: crc64: include <linux/crc64.h> for 'crc64_be'
  bcache: use read_cache_page_gfp to read the superblock
  bcache: store a pointer to the on-disk sb in the cache and cached_dev structures
  bcache: return a pointer to the on-disk sb from read_super
  bcache: transfer the sb_page reference to register_{bdev,cache}
  bcache: fix use-after-free in register_bcache()
  bcache: properly initialize 'path' and 'err' in register_bcache()
  bcache: rework error unwinding in register_bcache
  bcache: use a separate data structure for the on-disk super block
  bcache: cached_dev_free needs to put the sb page
  md/raid1: introduce wait_for_serialization
  md/raid1: use bucket based mechanism for IO serialization
  md: introduce a new struct for IO serialization
  md: don't destroy serial_info_pool if serialize_policy is true
  ...

lib/crc64.c

@@ -28,6 +28,7 @@
 
 #include <linux/module.h>
 #include <linux/types.h>
+#include <linux/crc64.h>
 #include "crc64table.h"
 
 MODULE_DESCRIPTION("CRC64 calculations");

lib/raid6/algos.c

@@ -124,6 +124,9 @@ const struct raid6_recov_calls *const raid6_recov_algos[] = {
 #define time_before(x, y) ((x) < (y))
 #endif
 
+#define RAID6_TEST_DISKS	8
+#define RAID6_TEST_DISKS_ORDER	3
+
 static inline const struct raid6_recov_calls *raid6_choose_recov(void)
 {
 	const struct raid6_recov_calls *const *algo;
@@ -146,7 +149,7 @@ static inline const struct raid6_recov_calls *raid6_choose_recov(void)
 }
 
 static inline const struct raid6_calls *raid6_choose_gen(
-	void *(*const dptrs)[(65536/PAGE_SIZE)+2], const int disks)
+	void *(*const dptrs)[RAID6_TEST_DISKS], const int disks)
 {
 	unsigned long perf, bestgenperf, bestxorperf, j0, j1;
 	int start = (disks>>1)-1, stop = disks-3;	/* work on the second half of the disks */
@@ -181,7 +184,8 @@ static inline const struct raid6_calls *raid6_choose_gen(
 				best = *algo;
 			}
 			pr_info("raid6: %-8s gen() %5ld MB/s\n", (*algo)->name,
-			       (perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2));
+				(perf * HZ * (disks-2)) >>
+				(20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2));
 
 			if (!(*algo)->xor_syndrome)
 				continue;
@@ -204,17 +208,24 @@ static inline const struct raid6_calls *raid6_choose_gen(
 				bestxorperf = perf;
 
 			pr_info("raid6: %-8s xor() %5ld MB/s\n", (*algo)->name,
-				(perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2+1));
+				(perf * HZ * (disks-2)) >>
+				(20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2 + 1));
 		}
 	}
 
 	if (best) {
-		pr_info("raid6: using algorithm %s gen() %ld MB/s\n",
-		       best->name,
-		       (bestgenperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2));
-		if (best->xor_syndrome)
-			pr_info("raid6: .... xor() %ld MB/s, rmw enabled\n",
-			       (bestxorperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2+1));
+		if (IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK)) {
+			pr_info("raid6: using algorithm %s gen() %ld MB/s\n",
+				best->name,
+				(bestgenperf * HZ * (disks-2)) >>
+				(20 - PAGE_SHIFT+RAID6_TIME_JIFFIES_LG2));
+			if (best->xor_syndrome)
+				pr_info("raid6: .... xor() %ld MB/s, rmw enabled\n",
+					(bestxorperf * HZ * (disks-2)) >>
+					(20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2 + 1));
+		} else
+			pr_info("raid6: skip pq benchmark and using algorithm %s\n",
+				best->name);
 		raid6_call = *best;
 	} else
 		pr_err("raid6: Yikes!  No algorithm found!\n");
@@ -228,27 +239,33 @@ static inline const struct raid6_calls *raid6_choose_gen(
 
 int __init raid6_select_algo(void)
 {
-	const int disks = (65536/PAGE_SIZE)+2;
+	const int disks = RAID6_TEST_DISKS;
 
 	const struct raid6_calls *gen_best;
 	const struct raid6_recov_calls *rec_best;
-	char *syndromes;
-	void *dptrs[(65536/PAGE_SIZE)+2];
-	int i;
+	char *disk_ptr, *p;
+	void *dptrs[RAID6_TEST_DISKS];
+	int i, cycle;
 
-	for (i = 0; i < disks-2; i++)
-		dptrs[i] = ((char *)raid6_gfmul) + PAGE_SIZE*i;
-
-	/* Normal code - use a 2-page allocation to avoid D$ conflict */
-	syndromes = (void *) __get_free_pages(GFP_KERNEL, 1);
-
-	if (!syndromes) {
+	/* prepare the buffer and fill it circularly with gfmul table */
+	disk_ptr = (char *)__get_free_pages(GFP_KERNEL, RAID6_TEST_DISKS_ORDER);
+	if (!disk_ptr) {
 		pr_err("raid6: Yikes!  No memory available.\n");
 		return -ENOMEM;
 	}
 
-	dptrs[disks-2] = syndromes;
-	dptrs[disks-1] = syndromes + PAGE_SIZE;
+	p = disk_ptr;
+	for (i = 0; i < disks; i++)
+		dptrs[i] = p + PAGE_SIZE * i;
+
+	cycle = ((disks - 2) * PAGE_SIZE) / 65536;
+	for (i = 0; i < cycle; i++) {
+		memcpy(p, raid6_gfmul, 65536);
+		p += 65536;
+	}
+
+	if ((disks - 2) * PAGE_SIZE % 65536)
+		memcpy(p, raid6_gfmul, (disks - 2) * PAGE_SIZE % 65536);
 
 	/* select raid gen_syndrome function */
 	gen_best = raid6_choose_gen(&dptrs, disks);
@@ -256,7 +273,7 @@ int __init raid6_select_algo(void)
 	/* select raid recover functions */
 	rec_best = raid6_choose_recov();
 
-	free_pages((unsigned long)syndromes, 1);
+	free_pages((unsigned long)disk_ptr, RAID6_TEST_DISKS_ORDER);
 
 	return gen_best && rec_best ? 0 : -EINVAL;
 }

lib/raid6/mktables.c

@@ -56,8 +56,8 @@ int main(int argc, char *argv[])
 	uint8_t v;
 	uint8_t exptbl[256], invtbl[256];
 
-	printf("#include <linux/raid/pq.h>\n");
 	printf("#include <linux/export.h>\n");
+	printf("#include <linux/raid/pq.h>\n");
 
 	/* Compute multiplication table */
 	printf("\nconst u8  __attribute__((aligned(256)))\n"