Merge tag 'for-5.16/scsi-ma-2021-10-29' of git://git.kernel.dk/linux-block

Pull SCSI multi-actuator support from Jens Axboe:
 "This adds SCSI support for the recently merged block multi-actuator
  support. Since this was sitting on top of the block tree, the SCSI
  side asked me to queue it up."

* tag 'for-5.16/scsi-ma-2021-10-29' of git://git.kernel.dk/linux-block:
  doc: Fix typo in request queue sysfs documentation
  doc: document sysfs queue/independent_access_ranges attributes
  libata: support concurrent positioning ranges log
  scsi: sd: add concurrent positioning ranges support

2 files changed, 82 insertions, 0 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 9bdee968d3b5..f75cfc97982d 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3088,6 +3088,86 @@ static void sd_read_security(struct scsi_disk *sdkp, unsigned char *buffer)
 		sdkp->security = 1;
 }
 
+static inline sector_t sd64_to_sectors(struct scsi_disk *sdkp, u8 *buf)
+{
+	return logical_to_sectors(sdkp->device, get_unaligned_be64(buf));
+}
+
+/**
+ * sd_read_cpr - Query concurrent positioning ranges
+ * @sdkp:	disk to query
+ */
+static void sd_read_cpr(struct scsi_disk *sdkp)
+{
+	struct blk_independent_access_ranges *iars = NULL;
+	unsigned char *buffer = NULL;
+	unsigned int nr_cpr = 0;
+	int i, vpd_len, buf_len = SD_BUF_SIZE;
+	u8 *desc;
+
+	/*
+	 * We need to have the capacity set first for the block layer to be
+	 * able to check the ranges.
+	 */
+	if (sdkp->first_scan)
+		return;
+
+	if (!sdkp->capacity)
+		goto out;
+
+	/*
+	 * Concurrent Positioning Ranges VPD: there can be at most 256 ranges,
+	 * leading to a maximum page size of 64 + 256*32 bytes.
+	 */
+	buf_len = 64 + 256*32;
+	buffer = kmalloc(buf_len, GFP_KERNEL);
+	if (!buffer || scsi_get_vpd_page(sdkp->device, 0xb9, buffer, buf_len))
+		goto out;
+
+	/* We must have at least a 64B header and one 32B range descriptor */
+	vpd_len = get_unaligned_be16(&buffer[2]) + 3;
+	if (vpd_len > buf_len || vpd_len < 64 + 32 || (vpd_len & 31)) {
+		sd_printk(KERN_ERR, sdkp,
+			  "Invalid Concurrent Positioning Ranges VPD page\n");
+		goto out;
+	}
+
+	nr_cpr = (vpd_len - 64) / 32;
+	if (nr_cpr == 1) {
+		nr_cpr = 0;
+		goto out;
+	}
+
+	iars = disk_alloc_independent_access_ranges(sdkp->disk, nr_cpr);
+	if (!iars) {
+		nr_cpr = 0;
+		goto out;
+	}
+
+	desc = &buffer[64];
+	for (i = 0; i < nr_cpr; i++, desc += 32) {
+		if (desc[0] != i) {
+			sd_printk(KERN_ERR, sdkp,
+				"Invalid Concurrent Positioning Range number\n");
+			nr_cpr = 0;
+			break;
+		}
+
+		iars->ia_range[i].sector = sd64_to_sectors(sdkp, desc + 8);
+		iars->ia_range[i].nr_sectors = sd64_to_sectors(sdkp, desc + 16);
+	}
+
+out:
+	disk_set_independent_access_ranges(sdkp->disk, iars);
+	if (nr_cpr && sdkp->nr_actuators != nr_cpr) {
+		sd_printk(KERN_NOTICE, sdkp,
+			  "%u concurrent positioning ranges\n", nr_cpr);
+		sdkp->nr_actuators = nr_cpr;
+	}
+
+	kfree(buffer);
+}
+
 /*
  * Determine the device's preferred I/O size for reads and writes
  * unless the reported value is unreasonably small, large, not a
@@ -3203,6 +3283,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
 		sd_read_app_tag_own(sdkp, buffer);
 		sd_read_write_same(sdkp, buffer);
 		sd_read_security(sdkp, buffer);
+		sd_read_cpr(sdkp);
 	}
 
 	/*
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index b59136c4125b..2e5932bde43d 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -106,6 +106,7 @@ struct scsi_disk {
 	u8		protection_type;/* Data Integrity Field */
 	u8		provisioning_mode;
 	u8		zeroing_mode;
+	u8		nr_actuators;		/* Number of actuators */
 	unsigned	ATO : 1;	/* state of disk ATO bit */
 	unsigned	cache_override : 1; /* temp override of WCE,RCD */
 	unsigned	WCE : 1;	/* state of disk WCE bit */