libata: make reset related methods proper port operations

Currently reset methods are not specified directly in the
ata_port_operations table.  If a LLD wants to use custom reset
methods, it should construct and use a error_handler which uses those
reset methods.  It's done this way for two reasons.

First, the ops table already contained too many methods and adding
four more of them would noticeably increase the amount of necessary
boilerplate code all over low level drivers.

Second, as ->error_handler uses those reset methods, it can get
confusing.  ie. By overriding ->error_handler, those reset ops can be
made useless making layering a bit hazy.

Now that ops table uses inheritance, the first problem doesn't exist
anymore.  The second isn't completely solved but is relieved by
providing default values - most drivers can just override what it has
implemented and don't have to concern itself about higher level
callbacks.  In fact, there currently is no driver which actually
modifies error handling behavior.  Drivers which override
->error_handler just wraps the standard error handler only to prepare
the controller for EH.  I don't think making ops layering strict has
any noticeable benefit.

This patch makes ->prereset, ->softreset, ->hardreset, ->postreset and
their PMP counterparts propoer ops.  Default ops are provided in the
base ops tables and drivers are converted to override individual reset
methods instead of creating custom error_handler.

* ata_std_error_handler() doesn't use sata_std_hardreset() if SCRs
  aren't accessible.  sata_promise doesn't need to use separate
  error_handlers for PATA and SATA anymore.

* softreset is broken for sata_inic162x and sata_sx4.  As libata now
  always prefers hardreset, this doesn't really matter but the ops are
  forced to NULL using ATA_OP_NULL for documentation purpose.

* pata_hpt374 needs to use different prereset for the first and second
  PCI functions.  This used to be done by branching from
  hpt374_error_handler().  The proper way to do this is to use
  separate ops and port_info tables for each function.  Converted.

Signed-off-by: Tejun Heo <htejun@gmail.com>

1 files changed, 10 insertions, 9 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 88c6fa84ed7..01c233303ae 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -693,6 +693,14 @@ struct ata_port_operations {
 
 	void (*freeze)(struct ata_port *ap);
 	void (*thaw)(struct ata_port *ap);
+	ata_prereset_fn_t	prereset;
+	ata_reset_fn_t		softreset;
+	ata_reset_fn_t		hardreset;
+	ata_postreset_fn_t	postreset;
+	ata_prereset_fn_t	pmp_prereset;
+	ata_reset_fn_t		pmp_softreset;
+	ata_reset_fn_t		pmp_hardreset;
+	ata_postreset_fn_t	pmp_postreset;
 	void (*error_handler)(struct ata_port *ap);
 	void (*post_internal_cmd)(struct ata_queued_cmd *qc);
 
@@ -909,10 +917,6 @@ extern void ata_bmdma_irq_clear(struct ata_port *ap);
 extern void ata_noop_irq_clear(struct ata_port *ap);
 extern void ata_bmdma_freeze(struct ata_port *ap);
 extern void ata_bmdma_thaw(struct ata_port *ap);
-extern void ata_bmdma_drive_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
-			       ata_reset_fn_t softreset,
-			       ata_reset_fn_t hardreset,
-			       ata_postreset_fn_t postreset);
 extern void ata_bmdma_error_handler(struct ata_port *ap);
 extern void ata_bmdma_post_internal_cmd(struct ata_queued_cmd *qc);
 extern int ata_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
@@ -1056,11 +1060,7 @@ extern int sata_pmp_std_prereset(struct ata_link *link, unsigned long deadline);
 extern int sata_pmp_std_hardreset(struct ata_link *link, unsigned int *class,
 				  unsigned long deadline);
 extern void sata_pmp_std_postreset(struct ata_link *link, unsigned int *class);
-extern void sata_pmp_do_eh(struct ata_port *ap,
-		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
-		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset,
-		ata_prereset_fn_t pmp_prereset, ata_reset_fn_t pmp_softreset,
-		ata_reset_fn_t pmp_hardreset, ata_postreset_fn_t pmp_postreset);
+extern void sata_pmp_error_handler(struct ata_port *ap);
 
 /*
  * EH
@@ -1080,6 +1080,7 @@ extern void ata_eh_qc_retry(struct ata_queued_cmd *qc);
 extern void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
 		      ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
 		      ata_postreset_fn_t postreset);
+extern void ata_std_error_handler(struct ata_port *ap);
 
 /*
  * Base operations to inherit from and initializers for sht