libata: implement ata_timing_cycle2mode() and use it in libata-acpi and pata_acpi

libata-acpi is using separate timing tables for transfer modes
although libata-core has the complete ata_timing table.  Implement
ata_timing_cycle2mode() to look for matching mode given transfer type
and cycle duration and use it in libata-acpi and pata_acpi to replace
private timing tables.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index 9f0b208..a6f1a6b 100644 (file)
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -441,22 +441,6 @@ static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf)
        return rc;
 }
 
-/* Welcome to ACPI, bring a bucket */
-const unsigned int ata_acpi_pio_cycle[7] = {
-       600, 383, 240, 180, 120, 100, 80
-};
-EXPORT_SYMBOL_GPL(ata_acpi_pio_cycle);
-
-const unsigned int ata_acpi_mwdma_cycle[5] = {
-       480, 150, 120, 100, 80
-};
-EXPORT_SYMBOL_GPL(ata_acpi_mwdma_cycle);
-
-const unsigned int ata_acpi_udma_cycle[7] = {
-       120, 80, 60, 45, 30, 20, 15
-};
-EXPORT_SYMBOL_GPL(ata_acpi_udma_cycle);
-
 /**
  * ata_acpi_gtm_xfermode - determine xfermode from GTM parameter
  * @dev: target device
@@ -473,49 +457,33 @@ EXPORT_SYMBOL_GPL(ata_acpi_udma_cycle);
 unsigned long ata_acpi_gtm_xfermask(struct ata_device *dev,
                                    const struct ata_acpi_gtm *gtm)
 {
-       unsigned long pio_mask = 0, mwdma_mask = 0, udma_mask = 0;
-       int unit, i;
-       u32 t;
+       unsigned long xfer_mask = 0;
+       unsigned int type;
+       int unit;
+       u8 mode;
 
        /* we always use the 0 slot for crap hardware */
        unit = dev->devno;
        if (!(gtm->flags & 0x10))
                unit = 0;
 
-       /* Values larger than the longest cycle results in 0 mask
-        * while values equal to smaller than the shortest cycle
-        * results in mask which includes all supported modes.
-        * Disabled transfer method has the value of 0xffffffff which
-        * will always result in 0 mask.
-        */
-
-       /* start by scanning for PIO modes */
-       t = gtm->drive[unit].pio;
-       for (i = 0; i < ARRAY_SIZE(ata_acpi_pio_cycle); i++)
-               if (t > ata_acpi_pio_cycle[i])
-                       break;
-       pio_mask = (1 << i) - 1;
+       /* PIO */
+       mode = ata_timing_cycle2mode(ATA_SHIFT_PIO, gtm->drive[unit].pio);
+       xfer_mask |= ata_xfer_mode2mask(mode);
 
        /* See if we have MWDMA or UDMA data. We don't bother with
         * MWDMA if UDMA is available as this means the BIOS set UDMA
         * and our error changedown if it works is UDMA to PIO anyway.
         */
-       t = gtm->drive[unit].dma;
-       if (!(gtm->flags & (1 << (2 * unit)))) {
-               /* MWDMA */
-               for (i = 0; i < ARRAY_SIZE(ata_acpi_mwdma_cycle); i++)
-                       if (t > ata_acpi_mwdma_cycle[i])
-                               break;
-               mwdma_mask = (1 << i) - 1;
-       } else {
-               /* UDMA */
-               for (i = 0; i < ARRAY_SIZE(ata_acpi_udma_cycle); i++)
-                       if (t > ata_acpi_udma_cycle[i])
-                               break;
-               udma_mask = (1 << i) - 1;
-       }
+       if (!(gtm->flags & (1 << (2 * unit))))
+               type = ATA_SHIFT_MWDMA;
+       else
+               type = ATA_SHIFT_UDMA;
+
+       mode = ata_timing_cycle2mode(type, gtm->drive[unit].dma);
+       xfer_mask |= ata_xfer_mode2mask(mode);
 
-       return ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
+       return xfer_mask;
 }
 EXPORT_SYMBOL_GPL(ata_acpi_gtm_xfermask);
 

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 62c4b32..f01c173 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2902,6 +2902,57 @@ int ata_timing_compute(struct ata_device *adev, unsigned short speed,
        return 0;
 }
 
+/**
+ *     ata_timing_cycle2mode - find xfer mode for the specified cycle duration
+ *     @xfer_shift: ATA_SHIFT_* value for transfer type to examine.
+ *     @cycle: cycle duration in ns
+ *
+ *     Return matching xfer mode for @cycle.  The returned mode is of
+ *     the transfer type specified by @xfer_shift.  If @cycle is too
+ *     slow for @xfer_shift, 0xff is returned.  If @cycle is faster
+ *     than the fastest known mode, the fasted mode is returned.
+ *
+ *     LOCKING:
+ *     None.
+ *
+ *     RETURNS:
+ *     Matching xfer_mode, 0xff if no match found.
+ */
+u8 ata_timing_cycle2mode(unsigned int xfer_shift, int cycle)
+{
+       u8 base_mode = 0xff, last_mode = 0xff;
+       const struct ata_xfer_ent *ent;
+       const struct ata_timing *t;
+
+       for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
+               if (ent->shift == xfer_shift)
+                       base_mode = ent->base;
+
+       for (t = ata_timing_find_mode(base_mode);
+            t && ata_xfer_mode2shift(t->mode) == xfer_shift; t++) {
+               unsigned short this_cycle;
+
+               switch (xfer_shift) {
+               case ATA_SHIFT_PIO:
+               case ATA_SHIFT_MWDMA:
+                       this_cycle = t->cycle;
+                       break;
+               case ATA_SHIFT_UDMA:
+                       this_cycle = t->udma;
+                       break;
+               default:
+                       return 0xff;
+               }
+
+               if (cycle > this_cycle)
+                       break;
+
+               last_mode = t->mode;
+       }
+
+       return last_mode;
+}
+
 /**
  *     ata_down_xfermask_limit - adjust dev xfer masks downward
  *     @dev: Device to adjust xfer masks
@@ -7630,6 +7681,7 @@ EXPORT_SYMBOL_GPL(ata_pio_need_iordy);
 EXPORT_SYMBOL_GPL(ata_timing_find_mode);
 EXPORT_SYMBOL_GPL(ata_timing_compute);
 EXPORT_SYMBOL_GPL(ata_timing_merge);
+EXPORT_SYMBOL_GPL(ata_timing_cycle2mode);
 
 #ifdef CONFIG_PCI
 EXPORT_SYMBOL_GPL(pci_test_config_bits);

diff --git a/drivers/ata/pata_acpi.c b/drivers/ata/pata_acpi.c
index a4737a3..244098a 100644 (file)
--- a/drivers/ata/pata_acpi.c
+++ b/drivers/ata/pata_acpi.c
@@ -133,13 +133,14 @@ static void pacpi_set_piomode(struct ata_port *ap, struct ata_device *adev)
 {
        int unit = adev->devno;
        struct pata_acpi *acpi = ap->private_data;
+       const struct ata_timing *t;
 
        if (!(acpi->gtm.flags & 0x10))
                unit = 0;
 
        /* Now stuff the nS values into the structure */
-       acpi->gtm.drive[unit].pio =
-               ata_acpi_pio_cycle[adev->pio_mode - XFER_PIO_0];
+       t = ata_timing_find_mode(adev->pio_mode);
+       acpi->gtm.drive[unit].pio = t->cycle;
        ata_acpi_stm(ap, &acpi->gtm);
        /* See what mode we actually got */
        ata_acpi_gtm(ap, &acpi->gtm);
@@ -155,18 +156,18 @@ static void pacpi_set_dmamode(struct ata_port *ap, struct ata_device *adev)
 {
        int unit = adev->devno;
        struct pata_acpi *acpi = ap->private_data;
+       const struct ata_timing *t;
 
        if (!(acpi->gtm.flags & 0x10))
                unit = 0;
 
        /* Now stuff the nS values into the structure */
+       t = ata_timing_find_mode(adev->dma_mode);
        if (adev->dma_mode >= XFER_UDMA_0) {
-               acpi->gtm.drive[unit].dma =
-                       ata_acpi_udma_cycle[adev->dma_mode - XFER_UDMA_0];
+               acpi->gtm.drive[unit].dma = t->udma;
                acpi->gtm.flags |= (1 << (2 * unit));
        } else {
-               acpi->gtm.drive[unit].dma =
-                       ata_acpi_mwdma_cycle[adev->dma_mode - XFER_MW_DMA_0];
+               acpi->gtm.drive[unit].dma = t->cycle;
                acpi->gtm.flags &= ~(1 << (2 * unit));
        }
        ata_acpi_stm(ap, &acpi->gtm);

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 8022e5b..8ede93b 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -941,6 +941,7 @@ extern int ata_timing_compute(struct ata_device *, unsigned short,
 extern void ata_timing_merge(const struct ata_timing *,
                             const struct ata_timing *, struct ata_timing *,
                             unsigned int);
+extern u8 ata_timing_cycle2mode(unsigned int xfer_shift, int cycle);
 
 enum {
        ATA_TIMING_SETUP        = (1 << 0),
@@ -961,10 +962,6 @@ enum {
 
 /* libata-acpi.c */
 #ifdef CONFIG_ATA_ACPI
-extern const unsigned int ata_acpi_pio_cycle[7];
-extern const unsigned int ata_acpi_mwdma_cycle[5];
-extern const unsigned int ata_acpi_udma_cycle[7];
-
 static inline const struct ata_acpi_gtm *ata_acpi_init_gtm(struct ata_port *ap)
 {
        if (ap->pflags & ATA_PFLAG_INIT_GTM_VALID)