ata: libata: Move sector_buf from struct ata_port to struct ata_device

The 512B buffer sector_buf field of struct ata_port is used for scanning
devices as well as during error recovery with ata EH. This buffer is
thus useless if a port does not have a device connected to it.
And also given that commands using this buffer are issued to devices,
and not to ports, move this buffer definition from struct ata_port to
struct ata_device.

This change slightly increases system memory usage for systems using a
port-multiplier as in that case we do not need a per-device buffer for
scanning devices (PMP does not allow parallel scanning) nor for EH (as
when entering EH we are guaranteed that all commands to all devices
connected to the PMP have completed or have been aborted). However,
this change reduces memory usage on systems that have many ports with
only few devices rives connected, which is a much more common use case
than the PMP use case.

Suggested-by: Niklas Cassel <[e-mail]>
Signed-off-by: Damien Le Moal <[e-mail]>
Reviewed-by: Hannes Reinecke <[e-mail]>
Reviewed-by: Niklas Cassel <[e-mail]>

drivers/ata/libata-core.c

···
 
 static int ata_log_supported(struct ata_device *dev, u8 log)
 {
-	struct ata_port *ap = dev->link->ap;
-
 	if (dev->quirks & ATA_QUIRK_NO_LOG_DIR)
 		return 0;
 
-	if (ata_read_log_page(dev, ATA_LOG_DIRECTORY, 0, ap->sector_buf, 1))
+	if (ata_read_log_page(dev, ATA_LOG_DIRECTORY, 0, dev->sector_buf, 1))
 		return 0;
-	return get_unaligned_le16(&ap->sector_buf[log * 2]);
+	return get_unaligned_le16(&dev->sector_buf[log * 2]);
 }
 
 static bool ata_identify_page_supported(struct ata_device *dev, u8 page)
 {
-	struct ata_port *ap = dev->link->ap;
 	unsigned int err, i;
 
 	if (dev->quirks & ATA_QUIRK_NO_ID_DEV_LOG)
···
 	 * Read IDENTIFY DEVICE data log, page 0, to figure out if the page is
 	 * supported.
 	 */
-	err = ata_read_log_page(dev, ATA_LOG_IDENTIFY_DEVICE, 0, ap->sector_buf,
-				1);
+	err = ata_read_log_page(dev, ATA_LOG_IDENTIFY_DEVICE, 0,
+				dev->sector_buf, 1);
 	if (err)
 		return false;
 
-	for (i = 0; i < ap->sector_buf[8]; i++) {
-		if (ap->sector_buf[9 + i] == page)
+	for (i = 0; i < dev->sector_buf[8]; i++) {
+		if (dev->sector_buf[9 + i] == page)
 			return true;
 	}
 
···
 
 static void ata_dev_config_ncq_send_recv(struct ata_device *dev)
 {
-	struct ata_port *ap = dev->link->ap;
 	unsigned int err_mask;
 
 	if (!ata_log_supported(dev, ATA_LOG_NCQ_SEND_RECV)) {
···
 		return;
 	}
 	err_mask = ata_read_log_page(dev, ATA_LOG_NCQ_SEND_RECV,
-				     0, ap->sector_buf, 1);
+				     0, dev->sector_buf, 1);
 	if (!err_mask) {
 		u8 *cmds = dev->ncq_send_recv_cmds;
 
 		dev->flags |= ATA_DFLAG_NCQ_SEND_RECV;
-		memcpy(cmds, ap->sector_buf, ATA_LOG_NCQ_SEND_RECV_SIZE);
+		memcpy(cmds, dev->sector_buf, ATA_LOG_NCQ_SEND_RECV_SIZE);
 
 		if (dev->quirks & ATA_QUIRK_NO_NCQ_TRIM) {
 			ata_dev_dbg(dev, "disabling queued TRIM support\n");
···
 
 static void ata_dev_config_ncq_non_data(struct ata_device *dev)
 {
-	struct ata_port *ap = dev->link->ap;
 	unsigned int err_mask;
 
 	if (!ata_log_supported(dev, ATA_LOG_NCQ_NON_DATA)) {
···
 		return;
 	}
 	err_mask = ata_read_log_page(dev, ATA_LOG_NCQ_NON_DATA,
-				     0, ap->sector_buf, 1);
-	if (!err_mask) {
-		u8 *cmds = dev->ncq_non_data_cmds;
-
-		memcpy(cmds, ap->sector_buf, ATA_LOG_NCQ_NON_DATA_SIZE);
-	}
+				     0, dev->sector_buf, 1);
+	if (!err_mask)
+		memcpy(dev->ncq_non_data_cmds, dev->sector_buf,
+		       ATA_LOG_NCQ_NON_DATA_SIZE);
 }
 
 static void ata_dev_config_ncq_prio(struct ata_device *dev)
 {
-	struct ata_port *ap = dev->link->ap;
 	unsigned int err_mask;
 
 	if (!ata_identify_page_supported(dev, ATA_LOG_SATA_SETTINGS))
···
 	err_mask = ata_read_log_page(dev,
 				     ATA_LOG_IDENTIFY_DEVICE,
 				     ATA_LOG_SATA_SETTINGS,
-				     ap->sector_buf,
-				     1);
+				     dev->sector_buf, 1);
 	if (err_mask)
 		goto not_supported;
 
-	if (!(ap->sector_buf[ATA_LOG_NCQ_PRIO_OFFSET] & BIT(3)))
+	if (!(dev->sector_buf[ATA_LOG_NCQ_PRIO_OFFSET] & BIT(3)))
 		goto not_supported;
 
 	dev->flags |= ATA_DFLAG_NCQ_PRIO;
···
 
 static void ata_dev_config_zac(struct ata_device *dev)
 {
-	struct ata_port *ap = dev->link->ap;
 	unsigned int err_mask;
-	u8 *identify_buf = ap->sector_buf;
+	u8 *identify_buf = dev->sector_buf;
 
 	dev->zac_zones_optimal_open = U32_MAX;
 	dev->zac_zones_optimal_nonseq = U32_MAX;
···
 
 static void ata_dev_config_trusted(struct ata_device *dev)
 {
-	struct ata_port *ap = dev->link->ap;
 	u64 trusted_cap;
 	unsigned int err;
 
···
 	}
 
 	err = ata_read_log_page(dev, ATA_LOG_IDENTIFY_DEVICE, ATA_LOG_SECURITY,
-			ap->sector_buf, 1);
+				dev->sector_buf, 1);
 	if (err)
 		return;
 
-	trusted_cap = get_unaligned_le64(&ap->sector_buf[40]);
+	trusted_cap = get_unaligned_le64(&dev->sector_buf[40]);
 	if (!(trusted_cap & (1ULL << 63))) {
 		ata_dev_dbg(dev,
 			    "Trusted Computing capability qword not valid!\n");
···
 
 	err_mask = ata_read_log_page(dev, ATA_LOG_IDENTIFY_DEVICE,
 				     ATA_LOG_SUPPORTED_CAPABILITIES,
-				     ap->sector_buf, 1);
+				     dev->sector_buf, 1);
 	if (err_mask)
 		goto not_supported;
 
 	/* Check Command Duration Limit Supported bits */
-	val = get_unaligned_le64(&ap->sector_buf[168]);
+	val = get_unaligned_le64(&dev->sector_buf[168]);
 	if (!(val & BIT_ULL(63)) || !(val & BIT_ULL(0)))
 		goto not_supported;
 
···
 	 * We must have support for the sense data for successful NCQ commands
 	 * log indicated by the successful NCQ command sense data supported bit.
 	 */
-	val = get_unaligned_le64(&ap->sector_buf[8]);
+	val = get_unaligned_le64(&dev->sector_buf[8]);
 	if (!(val & BIT_ULL(63)) || !(val & BIT_ULL(47))) {
 		ata_dev_warn(dev,
 			"CDL supported but Successful NCQ Command Sense Data is not supported\n");
···
 	 */
 	err_mask = ata_read_log_page(dev, ATA_LOG_IDENTIFY_DEVICE,
 				     ATA_LOG_CURRENT_SETTINGS,
-				     ap->sector_buf, 1);
+				     dev->sector_buf, 1);
 	if (err_mask)
 		goto not_supported;
 
-	val = get_unaligned_le64(&ap->sector_buf[8]);
+	val = get_unaligned_le64(&dev->sector_buf[8]);
 	cdl_enabled = val & BIT_ULL(63) && val & BIT_ULL(21);
 	if (dev->flags & ATA_DFLAG_CDL_ENABLED) {
 		if (!cdl_enabled) {
···
 	 * Command duration limits is supported: cache the CDL log page 18h
 	 * (command duration descriptors).
 	 */
-	err_mask = ata_read_log_page(dev, ATA_LOG_CDL, 0, ap->sector_buf, 1);
+	err_mask = ata_read_log_page(dev, ATA_LOG_CDL, 0, dev->sector_buf, 1);
 	if (err_mask) {
 		ata_dev_warn(dev, "Read Command Duration Limits log failed\n");
 		goto not_supported;
 	}
 
-	memcpy(dev->cdl, ap->sector_buf, ATA_LOG_CDL_SIZE);
+	memcpy(dev->cdl, dev->sector_buf, ATA_LOG_CDL_SIZE);
 	dev->flags |= ATA_DFLAG_CDL;
 
 	return;
···
 
 static void ata_dev_config_devslp(struct ata_device *dev)
 {
-	u8 *sata_setting = dev->link->ap->sector_buf;
+	u8 *sata_setting = dev->sector_buf;
 	unsigned int err_mask;
 	int i, j;
 
···
 int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags)
 {
 	unsigned int class = dev->class;
-	u16 *id = (void *)dev->link->ap->sector_buf;
+	u16 *id = (void *)dev->sector_buf;
 	int rc;
 
 	/* read ID data */

drivers/ata/libata-eh.c

···
 	int i;
 
 	for (i = 0; i < ATA_EH_UA_TRIES; i++) {
-		u8 *sense_buffer = dev->link->ap->sector_buf;
+		u8 *sense_buffer = dev->sector_buf;
 		u8 sense_key = 0;
 		unsigned int err_mask;
 

drivers/ata/libata-pmp.c

···
 static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
 {
 	struct ata_link *link = dev->link;
-	struct ata_port *ap = link->ap;
-	u32 *gscr = (void *)ap->sector_buf;
+	u32 *gscr = (void *)dev->sector_buf;
 	int rc;
 
 	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);

drivers/ata/libata-sata.c

···
 static int ata_eh_read_log_10h(struct ata_device *dev,
 			       int *tag, struct ata_taskfile *tf)
 {
-	u8 *buf = dev->link->ap->sector_buf;
+	u8 *buf = dev->sector_buf;
 	unsigned int err_mask;
 	u8 csum;
 	int i;

drivers/ata/libata-zpodd.c

···
 	if (!ret || sense_key != NOT_READY)
 		return false;
 
-	sense_buf = dev->link->ap->sector_buf;
+	sense_buf = dev->sector_buf;
 	ret = atapi_eh_request_sense(dev, sense_buf, sense_key);
 	if (ret)
 		return false;

include/linux/libata.h

···
 	int			spdn_cnt;
 	/* ering is CLEAR_END, read comment above CLEAR_END */
 	struct ata_ering	ering;
+
+	/* For EH */
+	u8			sector_buf[ATA_SECT_SIZE] ____cacheline_aligned;
 };
 
 /* Fields between ATA_DEVICE_CLEAR_BEGIN and ATA_DEVICE_CLEAR_END are
···
 #endif
 	/* owned by EH */
 	u8			*ncq_sense_buf;
-	u8			sector_buf[ATA_SECT_SIZE] ____cacheline_aligned;
 };
 
 /* The following initializer overrides a method to NULL whether one of