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

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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>
This commit is contained in:
Bartlomiej Zolnierkiewicz
2007-05-10 00:01:08 +02:00
parent 1813720723
commit 2d5eaa6dd7
27 changed files with 236 additions and 574 deletions
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125
drivers/ide/ide-lib.c
View File

@@ -69,123 +69,34 @@ char *ide_xfer_verbose (u8 xfer_rate)
EXPORT_SYMBOL(ide_xfer_verbose);
/**
* ide_dma_speed - compute DMA speed
* @drive: drive
* @mode: modes available
*
* Checks the drive capabilities and returns the speed to use
* for the DMA transfer. Returns 0 if the drive is incapable
* of DMA transfers.
*/
u8 ide_dma_speed(ide_drive_t *drive, u8 mode)
{
struct hd_driveid *id = drive->id;
ide_hwif_t *hwif = HWIF(drive);
u8 ultra_mask, mwdma_mask, swdma_mask;
u8 speed = 0;
if (drive->media != ide_disk && hwif->atapi_dma == 0)
return 0;
/* Capable of UltraDMA modes? */
ultra_mask = id->dma_ultra & hwif->ultra_mask;
if (!(id->field_valid & 4))
mode = 0; /* fallback to MW/SW DMA if no UltraDMA */
switch (mode) {
case 4:
if (ultra_mask & 0x40) {
speed = XFER_UDMA_6;
break;
}
case 3:
if (ultra_mask & 0x20) {
speed = XFER_UDMA_5;
break;
}
case 2:
if (ultra_mask & 0x10) {
speed = XFER_UDMA_4;
break;
}
if (ultra_mask & 0x08) {
speed = XFER_UDMA_3;
break;
}
case 1:
if (ultra_mask & 0x04) {
speed = XFER_UDMA_2;
break;
}
if (ultra_mask & 0x02) {
speed = XFER_UDMA_1;
break;
}
if (ultra_mask & 0x01) {
speed = XFER_UDMA_0;
break;
}
case 0:
mwdma_mask = id->dma_mword & hwif->mwdma_mask;
if (mwdma_mask & 0x04) {
speed = XFER_MW_DMA_2;
break;
}
if (mwdma_mask & 0x02) {
speed = XFER_MW_DMA_1;
break;
}
if (mwdma_mask & 0x01) {
speed = XFER_MW_DMA_0;
break;
}
swdma_mask = id->dma_1word & hwif->swdma_mask;
if (swdma_mask & 0x04) {
speed = XFER_SW_DMA_2;
break;
}
if (swdma_mask & 0x02) {
speed = XFER_SW_DMA_1;
break;
}
if (swdma_mask & 0x01) {
speed = XFER_SW_DMA_0;
break;
}
}
return speed;
}
EXPORT_SYMBOL(ide_dma_speed);
/**
* ide_rate_filter - return best speed for mode
* @mode: modes available
* ide_rate_filter - filter transfer mode
* @drive: IDE device
* @speed: desired speed
*
* Given the available DMA/UDMA mode this function returns
* Given the available transfer modes this function returns
* the best available speed at or below the speed requested.
*
* FIXME: filter also PIO/SWDMA/MWDMA modes
*/
u8 ide_rate_filter (u8 mode, u8 speed)
u8 ide_rate_filter(ide_drive_t *drive, u8 speed)
{
#ifdef CONFIG_BLK_DEV_IDEDMA
static u8 speed_max[] = {
XFER_MW_DMA_2, XFER_UDMA_2, XFER_UDMA_4,
XFER_UDMA_5, XFER_UDMA_6
};
ide_hwif_t *hwif = drive->hwif;
u8 mask = hwif->ultra_mask, mode = XFER_MW_DMA_2;
if (hwif->udma_filter)
mask = hwif->udma_filter(drive);
if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))
mask &= 0x07;
if (mask)
mode = fls(mask) - 1 + XFER_UDMA_0;
// printk("%s: mode 0x%02x, speed 0x%02x\n", __FUNCTION__, mode, speed);
/* So that we remember to update this if new modes appear */
BUG_ON(mode > 4);
return min(speed, speed_max[mode]);
return min(speed, mode);
#else /* !CONFIG_BLK_DEV_IDEDMA */
return min(speed, (u8)XFER_PIO_4);
#endif /* CONFIG_BLK_DEV_IDEDMA */