1 files changed, 20 insertions, 8 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 9fbf0595f3d..e7ea77cf606 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -57,6 +57,7 @@
 #include <linux/scatterlist.h>
 #include <linux/io.h>
 #include <linux/async.h>
+#include <linux/log2.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_host.h>
@@ -1322,14 +1323,16 @@ static u64 ata_id_n_sectors(const u16 *id)
 {
 	if (ata_id_has_lba(id)) {
 		if (ata_id_has_lba48(id))
-			return ata_id_u64(id, 100);
+			return ata_id_u64(id, ATA_ID_LBA_CAPACITY_2);
 		else
-			return ata_id_u32(id, 60);
+			return ata_id_u32(id, ATA_ID_LBA_CAPACITY);
 	} else {
 		if (ata_id_current_chs_valid(id))
-			return ata_id_u32(id, 57);
+			return id[ATA_ID_CUR_CYLS] * id[ATA_ID_CUR_HEADS] *
+			       id[ATA_ID_CUR_SECTORS];
 		else
-			return id[1] * id[3] * id[6];
+			return id[ATA_ID_CYLS] * id[ATA_ID_HEADS] *
+			       id[ATA_ID_SECTORS];
 	}
 }
 
@@ -2387,6 +2390,7 @@ int ata_dev_configure(struct ata_device *dev)
 	dev->cylinders = 0;
 	dev->heads = 0;
 	dev->sectors = 0;
+	dev->multi_count = 0;
 
 	/*
 	 * common ATA, ATAPI feature tests
@@ -2424,8 +2428,15 @@ int ata_dev_configure(struct ata_device *dev)
 
 		dev->n_sectors = ata_id_n_sectors(id);
 
-		if (dev->id[59] & 0x100)
-			dev->multi_count = dev->id[59] & 0xff;
+		/* get current R/W Multiple count setting */
+		if ((dev->id[47] >> 8) == 0x80 && (dev->id[59] & 0x100)) {
+			unsigned int max = dev->id[47] & 0xff;
+			unsigned int cnt = dev->id[59] & 0xff;
+			/* only recognize/allow powers of two here */
+			if (is_power_of_2(max) && is_power_of_2(cnt))
+				if (cnt <= max)
+					dev->multi_count = cnt;
+		}
 
 		if (ata_id_has_lba(id)) {
 			const char *lba_desc;
@@ -4612,7 +4623,7 @@ void ata_sg_clean(struct ata_queued_cmd *qc)
 	VPRINTK("unmapping %u sg elements\n", qc->n_elem);
 
 	if (qc->n_elem)
-		dma_unmap_sg(ap->dev, sg, qc->n_elem, dir);
+		dma_unmap_sg(ap->dev, sg, qc->orig_n_elem, dir);
 
 	qc->flags &= ~ATA_QCFLAG_DMAMAP;
 	qc->sg = NULL;
@@ -4727,7 +4738,7 @@ static int ata_sg_setup(struct ata_queued_cmd *qc)
 		return -1;
 
 	DPRINTK("%d sg elements mapped\n", n_elem);
-
+	qc->orig_n_elem = qc->n_elem;
 	qc->n_elem = n_elem;
 	qc->flags |= ATA_QCFLAG_DMAMAP;
 
@@ -6707,6 +6718,7 @@ EXPORT_SYMBOL_GPL(ata_id_c_string);
 EXPORT_SYMBOL_GPL(ata_do_dev_read_id);
 EXPORT_SYMBOL_GPL(ata_scsi_simulate);
 
+EXPORT_SYMBOL_GPL(ata_pio_queue_task);
 EXPORT_SYMBOL_GPL(ata_pio_need_iordy);
 EXPORT_SYMBOL_GPL(ata_timing_find_mode);
 EXPORT_SYMBOL_GPL(ata_timing_compute);