libata: separate out ata_acpi_gtm_xfermask() from pacpi_discover_modes()

Finding out matching transfer mode from ACPI GTM values is useful for
other purposes too.  Separate out the function and timing tables from
pata_acpi::pacpi_discover_modes().

Other than checking shared-configuration bit after doing
ata_acpi_gtm() in pacpi_discover_modes() which should be safe, this
patch doesn't introduce any behavior change.

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 ebc4dfcf2f19bd4beb1e1d2cb48c671385a7b9a8..d6697baf243d3227b9dc442e6ff6d13390fcccb7 100644 (file)
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -441,6 +441,84 @@ 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
+ * @gtm: GTM parameter to use
+ *
+ * Determine xfermask for @dev from @gtm.
+ *
+ * LOCKING:
+ * None.
+ *
+ * RETURNS:
+ * Determined xfermask.
+ */
+unsigned long ata_acpi_gtm_xfermask(struct ata_device *dev,
+                                   const struct ata_acpi_gtm *gtm)
+{
+       int unit, i;
+       u32 t;
+       unsigned long mask = (0x7f << ATA_SHIFT_UDMA) | (0x7 << ATA_SHIFT_MWDMA) | (0x1F << ATA_SHIFT_PIO);
+
+       /* we always use the 0 slot for crap hardware */
+       unit = dev->devno;
+       if (!(gtm->flags & 0x10))
+               unit = 0;
+
+       /* start by scanning for PIO modes */
+       for (i = 0; i < 7; i++) {
+               t = gtm->drive[unit].pio;
+               if (t <= ata_acpi_pio_cycle[i]) {
+                       mask |= (2 << (ATA_SHIFT_PIO + i)) - 1;
+                       break;
+               }
+       }
+
+       /* 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.
+        */
+       if (gtm->flags & (1 << (2 * unit))) {
+               /* MWDMA */
+               for (i = 0; i < 5; i++) {
+                       t = gtm->drive[unit].dma;
+                       if (t <= ata_acpi_mwdma_cycle[i]) {
+                               mask |= (2 << (ATA_SHIFT_MWDMA + i)) - 1;
+                               break;
+                       }
+               }
+       } else {
+               /* UDMA */
+               for (i = 0; i < 7; i++) {
+                       t = gtm->drive[unit].dma;
+                       if (t <= ata_acpi_udma_cycle[i]) {
+                               mask |= (2 << (ATA_SHIFT_UDMA + i)) - 1;
+                               break;
+                       }
+               }
+       }
+
+       return mask;
+}
+EXPORT_SYMBOL_GPL(ata_acpi_gtm_xfermask);
+
 /**
  * ata_acpi_cbl_80wire         -       Check for 80 wire cable
  * @ap: Port to check

diff --git a/drivers/ata/pata_acpi.c b/drivers/ata/pata_acpi.c
index e4542ab9c7f840fcf59102c8e92bb6422f79ff48..a4737a3d31cbd67c12249dfbe596a0d7e35f1350 100644 (file)
--- a/drivers/ata/pata_acpi.c
+++ b/drivers/ata/pata_acpi.c
@@ -81,17 +81,6 @@ static void pacpi_error_handler(struct ata_port *ap)
                                  NULL, ata_std_postreset);
 }
 
-/* Welcome to ACPI, bring a bucket */
-static const unsigned int pio_cycle[7] = {
-       600, 383, 240, 180, 120, 100, 80
-};
-static const unsigned int mwdma_cycle[5] = {
-       480, 150, 120, 100, 80
-};
-static const unsigned int udma_cycle[7] = {
-       120, 80, 60, 45, 30, 20, 15
-};
-
 /**
  *     pacpi_discover_modes    -       filter non ACPI modes
  *     @adev: ATA device
@@ -103,56 +92,20 @@ static const unsigned int udma_cycle[7] = {
 
 static unsigned long pacpi_discover_modes(struct ata_port *ap, struct ata_device *adev)
 {
-       int unit = adev->devno;
        struct pata_acpi *acpi = ap->private_data;
-       int i;
-       u32 t;
-       unsigned long mask = (0x7f << ATA_SHIFT_UDMA) | (0x7 << ATA_SHIFT_MWDMA) | (0x1F << ATA_SHIFT_PIO);
-
        struct ata_acpi_gtm probe;
+       unsigned int xfer_mask;
 
        probe = acpi->gtm;
 
-       /* We always use the 0 slot for crap hardware */
-       if (!(probe.flags & 0x10))
-               unit = 0;
-
        ata_acpi_gtm(ap, &probe);
 
-       /* Start by scanning for PIO modes */
-       for (i = 0; i < 7; i++) {
-               t = probe.drive[unit].pio;
-               if (t <= pio_cycle[i]) {
-                       mask |= (2 << (ATA_SHIFT_PIO + i)) - 1;
-                       break;
-               }
-       }
+       xfer_mask = ata_acpi_gtm_xfermask(adev, &probe);
 
-       /* See if we have MWDMA or UDMA data. We don't bother with MWDMA
-          if UDMA is availabe as this means the BIOS set UDMA and our
-          error changedown if it works is UDMA to PIO anyway */
-       if (probe.flags & (1 << (2 * unit))) {
-               /* MWDMA */
-               for (i = 0; i < 5; i++) {
-                       t = probe.drive[unit].dma;
-                       if (t <= mwdma_cycle[i]) {
-                               mask |= (2 << (ATA_SHIFT_MWDMA + i)) - 1;
-                               break;
-                       }
-               }
-       } else {
-               /* UDMA */
-               for (i = 0; i < 7; i++) {
-                       t = probe.drive[unit].dma;
-                       if (t <= udma_cycle[i]) {
-                               mask |= (2 << (ATA_SHIFT_UDMA + i)) - 1;
-                               break;
-                       }
-               }
-       }
-       if (mask & (0xF8 << ATA_SHIFT_UDMA))
+       if (xfer_mask & (0xF8 << ATA_SHIFT_UDMA))
                ap->cbl = ATA_CBL_PATA80;
-       return mask;
+
+       return xfer_mask;
 }
 
 /**
@@ -185,7 +138,8 @@ static void pacpi_set_piomode(struct ata_port *ap, struct ata_device *adev)
                unit = 0;
 
        /* Now stuff the nS values into the structure */
-       acpi->gtm.drive[unit].pio = pio_cycle[adev->pio_mode - XFER_PIO_0];
+       acpi->gtm.drive[unit].pio =
+               ata_acpi_pio_cycle[adev->pio_mode - XFER_PIO_0];
        ata_acpi_stm(ap, &acpi->gtm);
        /* See what mode we actually got */
        ata_acpi_gtm(ap, &acpi->gtm);
@@ -207,10 +161,12 @@ static void pacpi_set_dmamode(struct ata_port *ap, struct ata_device *adev)
 
        /* Now stuff the nS values into the structure */
        if (adev->dma_mode >= XFER_UDMA_0) {
-               acpi->gtm.drive[unit].dma = udma_cycle[adev->dma_mode - XFER_UDMA_0];
+               acpi->gtm.drive[unit].dma =
+                       ata_acpi_udma_cycle[adev->dma_mode - XFER_UDMA_0];
                acpi->gtm.flags |= (1 << (2 * unit));
        } else {
-               acpi->gtm.drive[unit].dma = mwdma_cycle[adev->dma_mode - XFER_MW_DMA_0];
+               acpi->gtm.drive[unit].dma =
+                       ata_acpi_mwdma_cycle[adev->dma_mode - XFER_MW_DMA_0];
                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 bdb7c6e13993502ffe129981869363d311f5087b..8022e5b2224d9863d1b71145222b3e8c8672f93d 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -961,6 +961,10 @@ 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)
@@ -970,12 +974,33 @@ static inline const struct ata_acpi_gtm *ata_acpi_init_gtm(struct ata_port *ap)
 extern int ata_acpi_cbl_80wire(struct ata_port *ap);
 int ata_acpi_stm(struct ata_port *ap, const struct ata_acpi_gtm *stm);
 int ata_acpi_gtm(struct ata_port *ap, struct ata_acpi_gtm *stm);
+unsigned long ata_acpi_gtm_xfermask(struct ata_device *dev,
+                                   const struct ata_acpi_gtm *gtm);
+
 #else
 static inline const struct ata_acpi_gtm *ata_acpi_init_gtm(struct ata_port *ap)
 {
        return NULL;
 }
 static inline int ata_acpi_cbl_80wire(struct ata_port *ap) { return 0; }
+
+static inline int ata_acpi_stm(const struct ata_port *ap,
+                              struct ata_acpi_gtm *stm)
+{
+       return -ENOSYS;
+}
+
+static inline int ata_acpi_gtm(const struct ata_port *ap,
+                              struct ata_acpi_gtm *stm)
+{
+       return -ENOSYS;
+}
+
+static inline unsigned int ata_acpi_gtm_xfermask(struct ata_device *dev,
+                                       const struct ata_acpi_gtm *gtm)
+{
+       return 0;
+}
 #endif
 
 #ifdef CONFIG_PCI