ide: rework the code for selecting the best DMA transfer mode (v3)

Depends on the "ide: fix UDMA/MWDMA/SWDMA masks" patch.

* add ide_hwif_t.udma_filter hook for filtering UDMA mask
  (use it in alim15x3, hpt366, siimage and serverworks drivers)
* add ide_max_dma_mode() for finding best DMA mode for the device
  (loosely based on some older libata-core.c code)
* convert ide_dma_speed() users to use ide_max_dma_mode()
* make ide_rate_filter() take "ide_drive_t *drive" as an argument instead
  of "u8 mode" and teach it to how to use UDMA mask to do filtering
* use ide_rate_filter() in hpt366 driver
* remove no longer needed ide_dma_speed() and *_ratemask()
* unexport eighty_ninty_three()

v2:
* rename ->filter_udma_mask to ->udma_filter
  [ Suggested by Sergei Shtylyov <sshtylyov@ru.mvista.com>. ]

v3:
* updated for scc_pata driver (fixes XFER_UDMA_6 filtering for user-space
  originated transfer mode change requests when 100MHz clock is used)

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/include/linux/ide.h b/include/linux/ide.h
index c9375c863584..23ab4dc05009 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -717,11 +717,8 @@ typedef struct hwif_s {
         int     (*quirkproc)(ide_drive_t *);
         /* driver soft-power interface */
         int     (*busproc)(ide_drive_t *, int);
-//      /* host rate limiter */
-//      u8      (*ratemask)(ide_drive_t *);
-//      /* device rate limiter */
-//      u8      (*ratefilter)(ide_drive_t *, u8);
 #endif
+        u8 (*udma_filter)(ide_drive_t *);
 
         void (*ata_input_data)(ide_drive_t *, void *, u32);
         void (*ata_output_data)(ide_drive_t *, void *, u32);
@@ -1279,6 +1276,7 @@ int ide_in_drive_list(struct hd_driveid *, const struct drive_list_entry *);
 int __ide_dma_bad_drive(ide_drive_t *);
 int __ide_dma_good_drive(ide_drive_t *);
 int ide_use_dma(ide_drive_t *);
+u8 ide_max_dma_mode(ide_drive_t *);
 void ide_dma_off(ide_drive_t *);
 void ide_dma_verbose(ide_drive_t *);
 int ide_set_dma(ide_drive_t *);
@@ -1305,6 +1303,7 @@ extern int __ide_dma_timeout(ide_drive_t *);
 
 #else
 static inline int ide_use_dma(ide_drive_t *drive) { return 0; }
+static inline u8 ide_max_dma_mode(ide_drive_t *drive) { return 0; }
 static inline void ide_dma_off(ide_drive_t *drive) { ; }
 static inline void ide_dma_verbose(ide_drive_t *drive) { ; }
 static inline int ide_set_dma(ide_drive_t *drive) { return 1; }
@@ -1349,8 +1348,7 @@ static inline void ide_set_hwifdata (ide_hwif_t * hwif, void *data)
 }
 
 /* ide-lib.c */
-extern u8 ide_dma_speed(ide_drive_t *drive, u8 mode);
-extern u8 ide_rate_filter(u8 mode, u8 speed); 
+u8 ide_rate_filter(ide_drive_t *, u8);
 extern int ide_dma_enable(ide_drive_t *drive);
 extern char *ide_xfer_verbose(u8 xfer_rate);
 extern void ide_toggle_bounce(ide_drive_t *drive, int on);