From e815d36548f01797ce381be8f0b74f4ba9befd15 Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Wed, 27 Oct 2021 11:22:20 +0900 Subject: scsi: sd: add concurrent positioning ranges support Add the sd_read_cpr() function to the sd scsi disk driver to discover if a device has multiple concurrent positioning ranges (i.e. multiple actuators on an HDD). The existence of VPD page B9h indicates if a device has multiple concurrent positioning ranges. The page content describes each range supported by the device. sd_read_cpr() is called from sd_revalidate_disk() and uses the block layer functions disk_alloc_independent_access_ranges() and disk_set_independent_access_ranges() to represent the set of actuators of the device as independent access ranges. The format of the Concurrent Positioning Ranges VPD page B9h is defined in section 6.6.6 of SBC-5. Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Martin K. Petersen Reviewed-by: Keith Busch Link: https://lore.kernel.org/r/20211027022223.183838-3-damien.lemoal@wdc.com Signed-off-by: Jens Axboe --- drivers/scsi/sd.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ drivers/scsi/sd.h | 1 + 2 files changed, 82 insertions(+) (limited to 'drivers/scsi') diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index d8f6add416c0..55c0d951a446 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 */ -- cgit