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 ebc4dfc..d6697ba 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -441,6 +441,84 @@
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