[PATCH] libata: implement dummy port
Implement dummy port which can be requested by setting appropriate bit
in probe_ent->dummy_port_mask. The dummy port is used as placeholder
for stolen legacy port. This allows libata to guarantee that
index_of(ap) == ap->port_no == actual_device_port_no, and thus to
remove error-prone ap->hard_port_no.
As it's used only when one port of a legacy controller is reserved by
some other entity (e.g. IDE), the focus is on keeping the added *code*
complexity at minimum, so dummy port allocates all libata core
resources and acts as a normal port. It just has all dummy port_ops.
This patch only implements dummy port. The following patch will make
libata use it for stolen legacy ports.
Signed-off-by: Tejun Heo <htejun@gmail.com>
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 4504776..30bfe8f 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -353,6 +353,7 @@
struct ata_ioports port[ATA_MAX_PORTS];
unsigned int n_ports;
unsigned int hard_port_no;
+ unsigned int dummy_port_mask;
unsigned int pio_mask;
unsigned int mwdma_mask;
unsigned int udma_mask;
@@ -652,6 +653,8 @@
extern const unsigned long sata_deb_timing_hotplug[];
extern const unsigned long sata_deb_timing_long[];
+extern const struct ata_port_operations ata_dummy_port_ops;
+
static inline const unsigned long *
sata_ehc_deb_timing(struct ata_eh_context *ehc)
{
@@ -661,6 +664,11 @@
return sata_deb_timing_normal;
}
+static inline int ata_port_is_dummy(struct ata_port *ap)
+{
+ return ap->ops == &ata_dummy_port_ops;
+}
+
extern void ata_port_probe(struct ata_port *);
extern void __sata_phy_reset(struct ata_port *ap);
extern void sata_phy_reset(struct ata_port *ap);