libata: Add H2D FIS "auxiliary" port flag

Add a new port flag, ATA_FLAG_FPDMA_AUX, used to indicate
support for transmission of the H2D FIS 'auxiliary' field.

Signed-off-by: Marc Carino <marc.ceeeee@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

2 files changed, 9 insertions, 0 deletions

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 5064f3ea20f1..8d41c57fd969 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1288,6 +1288,14 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
                  */
                 if (!(hpriv->flags & AHCI_HFLAG_NO_FPDMA_AA))
                         pi.flags |= ATA_FLAG_FPDMA_AA;
+
+                /*
+                 * All AHCI controllers should be forward-compatible
+                 * with the new auxiliary field. This code should be
+                 * conditionalized if any buggy AHCI controllers are
+                 * encountered.
+                 */
+                pi.flags |= ATA_FLAG_FPDMA_AUX;
         }
 
         if (hpriv->cap & HOST_CAP_PMP)
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 9b6ba196179f..578f98c3ff57 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -223,6 +223,7 @@ enum {
         ATA_FLAG_ACPI_SATA      = (1 << 17), /* need native SATA ACPI layout */
         ATA_FLAG_AN             = (1 << 18), /* controller supports AN */
         ATA_FLAG_PMP            = (1 << 19), /* controller supports PMP */
+        ATA_FLAG_FPDMA_AUX      = (1 << 20), /* controller supports H2DFIS aux field */
         ATA_FLAG_EM             = (1 << 21), /* driver supports enclosure
                                               * management */
         ATA_FLAG_SW_ACTIVITY    = (1 << 22), /* driver supports sw activity