Add support for PxSCT.LPM set based on actual LPM circumstances

zhaoxin inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I54V2K
CVE: NA

----------------------------------------------------------------

AHCI Spec shows that the PxSCTL.IPM field in each port must be programmed
to disallow device initiated LPM requests when HBA can not support
transitions to the LPM state. The current LPM driver has no restrictions
on LPM transitions when enabling device initiated LPM.
Signed-off-by: NLeoLiu-oc <LeoLiu-oc@zhaoxin.com>

drivers/ata/libata-core.c

@@ -3975,6 +3975,9 @@ int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
 		      bool spm_wakeup)
 {
 	struct ata_eh_context *ehc = &link->eh_context;
+	struct ata_port *ap = ata_is_host_link(link) ? link->ap : NULL;
+	struct device *dev = ap ? ap->host->dev : NULL;
+	struct pci_dev *pdev = (!dev || !dev_is_pci(dev)) ? NULL : to_pci_dev(dev);
 	bool woken_up = false;
 	u32 scontrol;
 	int rc;
@@ -4001,10 +4004,20 @@ int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
 	case ATA_LPM_MED_POWER_WITH_DIPM:
 	case ATA_LPM_MIN_POWER_WITH_PARTIAL:
 	case ATA_LPM_MIN_POWER:
-		if (ata_link_nr_enabled(link) > 0)
+		if (ata_link_nr_enabled(link) > 0) {
 			/* no restrictions on LPM transitions */
 			scontrol &= ~(0x7 << 8);
-		else {
+			/*
+			 * If Host does not support partial, then disallows it,
+			 * the same for slumber.
+			 */
+			if (pdev && pdev->vendor == PCI_VENDOR_ID_ZHAOXIN) {
+				if (!(link->ap->host->flags & ATA_HOST_PART))
+					scontrol |= (0x1 << 8);
+				if (!(link->ap->host->flags & ATA_HOST_SSC))
+					scontrol |= (0x2 << 8);
+			}
+		} else {
 			/* empty port, power off */
 			scontrol &= ~0xf;
 			scontrol |= (0x1 << 2);