libata-link: introduce ata_link

Introduce ata_link.  It abstracts PHY and sits between ata_port and
ata_device.  This new level of abstraction is necessary to support
SATA Port Multiplier, which basically adds a bunch of links (PHYs) to
a ATA host port.  Fields related to command execution, spd_limit and
EH are per-link and thus moved to ata_link.

This patch only defines the host link.  Multiple link handling will be
added later.  Also, a lot of ap->link derefences are added but many of
them will be removed as each part is converted to deal directly with
ata_link instead of ata_port.

This patch introduces no behavior change.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 11 insertions, 10 deletions

diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index c059f78ad944..0023ac4ff496 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -44,7 +44,8 @@ static void ata_acpi_associate_sata_port(struct ata_port *ap)
 {
         acpi_integer adr = SATA_ADR(ap->port_no, NO_PORT_MULT);
 
-        ap->device->acpi_handle = acpi_get_child(ap->host->acpi_handle, adr);
+        ap->link.device->acpi_handle =
+                acpi_get_child(ap->host->acpi_handle, adr);
 }
 
 static void ata_acpi_associate_ide_port(struct ata_port *ap)
@@ -60,7 +61,7 @@ static void ata_acpi_associate_ide_port(struct ata_port *ap)
                 max_devices++;
 
         for (i = 0; i < max_devices; i++) {
-                struct ata_device *dev = &ap->device[i];
+                struct ata_device *dev = &ap->link.device[i];
 
                 dev->acpi_handle = acpi_get_child(ap->acpi_handle, i);
         }
@@ -182,10 +183,10 @@ static int ata_acpi_stm(const struct ata_port *ap, struct ata_acpi_gtm *stm)
         /* Buffers for id may need byteswapping ? */
         in_params[1].type = ACPI_TYPE_BUFFER;
         in_params[1].buffer.length = 512;
-        in_params[1].buffer.pointer = (u8 *)ap->device[0].id;
+        in_params[1].buffer.pointer = (u8 *)ap->link.device[0].id;
         in_params[2].type = ACPI_TYPE_BUFFER;
         in_params[2].buffer.length = 512;
-        in_params[2].buffer.pointer = (u8 *)ap->device[1].id;
+        in_params[2].buffer.pointer = (u8 *)ap->link.device[1].id;
 
         input.count = 3;
         input.pointer = in_params;
@@ -226,7 +227,7 @@ static int ata_acpi_stm(const struct ata_port *ap, struct ata_acpi_gtm *stm)
 static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf,
                            void **ptr_to_free)
 {
-        struct ata_port *ap = dev->ap;
+        struct ata_port *ap = dev->link->ap;
         acpi_status status;
         struct acpi_buffer output;
         union acpi_object *out_obj;
@@ -320,7 +321,7 @@ static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf,
 static int taskfile_load_raw(struct ata_device *dev,
                               const struct ata_acpi_gtf *gtf)
 {
-        struct ata_port *ap = dev->ap;
+        struct ata_port *ap = dev->link->ap;
         struct ata_taskfile tf, rtf;
         unsigned int err_mask;
 
@@ -424,7 +425,7 @@ static int ata_acpi_exec_tfs(struct ata_device *dev)
  */
 static int ata_acpi_push_id(struct ata_device *dev)
 {
-        struct ata_port *ap = dev->ap;
+        struct ata_port *ap = dev->link->ap;
         int err;
         acpi_status status;
         struct acpi_object_list input;
@@ -519,7 +520,7 @@ void ata_acpi_on_resume(struct ata_port *ap)
 
         /* schedule _GTF */
         for (i = 0; i < ATA_MAX_DEVICES; i++)
-                ap->device[i].flags |= ATA_DFLAG_ACPI_PENDING;
+                ap->link.device[i].flags |= ATA_DFLAG_ACPI_PENDING;
 }
 
 /**
@@ -538,8 +539,8 @@ void ata_acpi_on_resume(struct ata_port *ap)
  */
 int ata_acpi_on_devcfg(struct ata_device *dev)
 {
-        struct ata_port *ap = dev->ap;
-        struct ata_eh_context *ehc = &ap->eh_context;
+        struct ata_port *ap = dev->link->ap;
+        struct ata_eh_context *ehc = &ap->link.eh_context;
         int acpi_sata = ap->flags & ATA_FLAG_ACPI_SATA;
         int rc;