[libata] change ata_qc_complete() to take error mask as second arg

The second argument to ata_qc_complete() was being used for two
purposes: communicate the ATA Status register to the completion
function, and indicate an error.  On legacy PCI IDE hardware, the latter
is often implicit in the former.  On more modern hardware, the driver
often completely emulated a Status register value, passing ATA_ERR as an
indication that something went wrong.

Now that previous code changes have eliminated the need to use drv_stat
arg to communicate the ATA Status register value, we can convert it to a
mask of possible error classes.

This will lead to more flexible error handling in the future.

1 files changed, 26 insertions, 2 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index a4cce99..0ba3af7 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -172,6 +172,13 @@ enum hsm_task_states {
 	HSM_ST_ERR,
 };
 
+enum ata_completion_errors {
+	AC_ERR_OTHER		= (1 << 0),
+	AC_ERR_DEV		= (1 << 1),
+	AC_ERR_ATA_BUS		= (1 << 2),
+	AC_ERR_HOST_BUS		= (1 << 3),
+};
+
 /* forward declarations */
 struct scsi_device;
 struct ata_port_operations;
@@ -179,7 +186,7 @@ struct ata_port;
 struct ata_queued_cmd;
 
 /* typedefs */
-typedef int (*ata_qc_cb_t) (struct ata_queued_cmd *qc, u8 drv_stat);
+typedef int (*ata_qc_cb_t) (struct ata_queued_cmd *qc, unsigned int err_mask);
 
 struct ata_ioports {
 	unsigned long		cmd_addr;
@@ -453,7 +460,7 @@ extern void ata_bmdma_start (struct ata_queued_cmd *qc);
 extern void ata_bmdma_stop(struct ata_queued_cmd *qc);
 extern u8   ata_bmdma_status(struct ata_port *ap);
 extern void ata_bmdma_irq_clear(struct ata_port *ap);
-extern void ata_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat);
+extern void ata_qc_complete(struct ata_queued_cmd *qc, unsigned int err_mask);
 extern void ata_eng_timeout(struct ata_port *ap);
 extern void ata_scsi_simulate(u16 *id, struct scsi_cmnd *cmd,
 			      void (*done)(struct scsi_cmnd *));
@@ -716,4 +723,21 @@ static inline int ata_try_flush_cache(const struct ata_device *dev)
 	       ata_id_has_flush_ext(dev->id);
 }
 
+static inline unsigned int ac_err_mask(u8 status)
+{
+	if (status & ATA_BUSY)
+		return AC_ERR_ATA_BUS;
+	if (status & (ATA_ERR | ATA_DF))
+		return AC_ERR_DEV;
+	return 0;
+}
+
+static inline unsigned int __ac_err_mask(u8 status)
+{
+	unsigned int mask = ac_err_mask(status);
+	if (mask == 0)
+		return AC_ERR_OTHER;
+	return mask;
+}
+
 #endif /* __LINUX_LIBATA_H__ */