ide: move xfer mode tuning code to ide-xfer-mode.c

* Move xfer mode tuning code to ide-xfer-mode.c.

* Add CONFIG_IDE_XFER_MODE config option to be selected by host drivers
  that support xfer mode tuning.

* Add CONFIG_IDE_XFER_MODE=n static inline versions of ide_set_pio()
  and ide_set_xfer_rate().

* Make IDE_TIMINGS and BLK_DEV_IDEDMA config options select IDE_XFER_MODE,
  also add explicit selects for few host drivers that need it.

* Build/link ide-xfer-mode.o and ide-pio-blacklist.o (it is needed only
  by ide-xfer-mode.o) only if CONFIG_IDE_XFER_MODE=y.

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

1 files changed, 246 insertions, 0 deletions

diff --git a/drivers/ide/ide-xfer-mode.c b/drivers/ide/ide-xfer-mode.c
new file mode 100644
index 000000000000..6910f6a257e8
--- /dev/null
+++ b/drivers/ide/ide-xfer-mode.c
@@ -0,0 +1,246 @@
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/ide.h>
+#include <linux/bitops.h>
+
+static const char *udma_str[] =
+         { "UDMA/16", "UDMA/25",  "UDMA/33",  "UDMA/44",
+           "UDMA/66", "UDMA/100", "UDMA/133", "UDMA7" };
+static const char *mwdma_str[] =
+        { "MWDMA0", "MWDMA1", "MWDMA2" };
+static const char *swdma_str[] =
+        { "SWDMA0", "SWDMA1", "SWDMA2" };
+static const char *pio_str[] =
+        { "PIO0", "PIO1", "PIO2", "PIO3", "PIO4", "PIO5" };
+
+/**
+ *      ide_xfer_verbose        -       return IDE mode names
+ *      @mode: transfer mode
+ *
+ *      Returns a constant string giving the name of the mode
+ *      requested.
+ */
+
+const char *ide_xfer_verbose(u8 mode)
+{
+        const char *s;
+        u8 i = mode & 0xf;
+
+        if (mode >= XFER_UDMA_0 && mode <= XFER_UDMA_7)
+                s = udma_str[i];
+        else if (mode >= XFER_MW_DMA_0 && mode <= XFER_MW_DMA_2)
+                s = mwdma_str[i];
+        else if (mode >= XFER_SW_DMA_0 && mode <= XFER_SW_DMA_2)
+                s = swdma_str[i];
+        else if (mode >= XFER_PIO_0 && mode <= XFER_PIO_5)
+                s = pio_str[i & 0x7];
+        else if (mode == XFER_PIO_SLOW)
+                s = "PIO SLOW";
+        else
+                s = "XFER ERROR";
+
+        return s;
+}
+EXPORT_SYMBOL(ide_xfer_verbose);
+
+/**
+ *      ide_get_best_pio_mode   -       get PIO mode from drive
+ *      @drive: drive to consider
+ *      @mode_wanted: preferred mode
+ *      @max_mode: highest allowed mode
+ *
+ *      This routine returns the recommended PIO settings for a given drive,
+ *      based on the drive->id information and the ide_pio_blacklist[].
+ *
+ *      Drive PIO mode is auto-selected if 255 is passed as mode_wanted.
+ *      This is used by most chipset support modules when "auto-tuning".
+ */
+
+u8 ide_get_best_pio_mode(ide_drive_t *drive, u8 mode_wanted, u8 max_mode)
+{
+        u16 *id = drive->id;
+        int pio_mode = -1, overridden = 0;
+
+        if (mode_wanted != 255)
+                return min_t(u8, mode_wanted, max_mode);
+
+        if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_BLACKLIST) == 0)
+                pio_mode = ide_scan_pio_blacklist((char *)&id[ATA_ID_PROD]);
+
+        if (pio_mode != -1) {
+                printk(KERN_INFO "%s: is on PIO blacklist\n", drive->name);
+        } else {
+                pio_mode = id[ATA_ID_OLD_PIO_MODES] >> 8;
+                if (pio_mode > 2) {     /* 2 is maximum allowed tPIO value */
+                        pio_mode = 2;
+                        overridden = 1;
+                }
+
+                if (id[ATA_ID_FIELD_VALID] & 2) {             /* ATA2? */
+                        if (ata_id_has_iordy(id)) {
+                                if (id[ATA_ID_PIO_MODES] & 7) {
+                                        overridden = 0;
+                                        if (id[ATA_ID_PIO_MODES] & 4)
+                                                pio_mode = 5;
+                                        else if (id[ATA_ID_PIO_MODES] & 2)
+                                                pio_mode = 4;
+                                        else
+                                                pio_mode = 3;
+                                }
+                        }
+                }
+
+                if (overridden)
+                        printk(KERN_INFO "%s: tPIO > 2, assuming tPIO = 2\n",
+                                         drive->name);
+        }
+
+        if (pio_mode > max_mode)
+                pio_mode = max_mode;
+
+        return pio_mode;
+}
+EXPORT_SYMBOL_GPL(ide_get_best_pio_mode);
+
+int ide_set_pio_mode(ide_drive_t *drive, const u8 mode)
+{
+        ide_hwif_t *hwif = drive->hwif;
+        const struct ide_port_ops *port_ops = hwif->port_ops;
+
+        if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
+                return 0;
+
+        if (port_ops == NULL || port_ops->set_pio_mode == NULL)
+                return -1;
+
+        /*
+         * TODO: temporary hack for some legacy host drivers that didn't
+         * set transfer mode on the device in ->set_pio_mode method...
+         */
+        if (port_ops->set_dma_mode == NULL) {
+                port_ops->set_pio_mode(drive, mode - XFER_PIO_0);
+                return 0;
+        }
+
+        if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
+                if (ide_config_drive_speed(drive, mode))
+                        return -1;
+                port_ops->set_pio_mode(drive, mode - XFER_PIO_0);
+                return 0;
+        } else {
+                port_ops->set_pio_mode(drive, mode - XFER_PIO_0);
+                return ide_config_drive_speed(drive, mode);
+        }
+}
+
+int ide_set_dma_mode(ide_drive_t *drive, const u8 mode)
+{
+        ide_hwif_t *hwif = drive->hwif;
+        const struct ide_port_ops *port_ops = hwif->port_ops;
+
+        if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
+                return 0;
+
+        if (port_ops == NULL || port_ops->set_dma_mode == NULL)
+                return -1;
+
+        if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
+                if (ide_config_drive_speed(drive, mode))
+                        return -1;
+                port_ops->set_dma_mode(drive, mode);
+                return 0;
+        } else {
+                port_ops->set_dma_mode(drive, mode);
+                return ide_config_drive_speed(drive, mode);
+        }
+}
+EXPORT_SYMBOL_GPL(ide_set_dma_mode);
+
+/* req_pio == "255" for auto-tune */
+void ide_set_pio(ide_drive_t *drive, u8 req_pio)
+{
+        ide_hwif_t *hwif = drive->hwif;
+        const struct ide_port_ops *port_ops = hwif->port_ops;
+        u8 host_pio, pio;
+
+        if (port_ops == NULL || port_ops->set_pio_mode == NULL ||
+            (hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
+                return;
+
+        BUG_ON(hwif->pio_mask == 0x00);
+
+        host_pio = fls(hwif->pio_mask) - 1;
+
+        pio = ide_get_best_pio_mode(drive, req_pio, host_pio);
+
+        /*
+         * TODO:
+         * - report device max PIO mode
+         * - check req_pio != 255 against device max PIO mode
+         */
+        printk(KERN_DEBUG "%s: host max PIO%d wanted PIO%d%s selected PIO%d\n",
+                          drive->name, host_pio, req_pio,
+                          req_pio == 255 ? "(auto-tune)" : "", pio);
+
+        (void)ide_set_pio_mode(drive, XFER_PIO_0 + pio);
+}
+EXPORT_SYMBOL_GPL(ide_set_pio);
+
+/**
+ *      ide_rate_filter         -       filter transfer mode
+ *      @drive: IDE device
+ *      @speed: desired speed
+ *
+ *      Given the available transfer modes this function returns
+ *      the best available speed at or below the speed requested.
+ *
+ *      TODO: check device PIO capabilities
+ */
+
+static u8 ide_rate_filter(ide_drive_t *drive, u8 speed)
+{
+        ide_hwif_t *hwif = drive->hwif;
+        u8 mode = ide_find_dma_mode(drive, speed);
+
+        if (mode == 0) {
+                if (hwif->pio_mask)
+                        mode = fls(hwif->pio_mask) - 1 + XFER_PIO_0;
+                else
+                        mode = XFER_PIO_4;
+        }
+
+/*      printk("%s: mode 0x%02x, speed 0x%02x\n", __func__, mode, speed); */
+
+        return min(speed, mode);
+}
+
+/**
+ *      ide_set_xfer_rate       -       set transfer rate
+ *      @drive: drive to set
+ *      @rate: speed to attempt to set
+ *
+ *      General helper for setting the speed of an IDE device. This
+ *      function knows about user enforced limits from the configuration
+ *      which ->set_pio_mode/->set_dma_mode does not.
+ */
+
+int ide_set_xfer_rate(ide_drive_t *drive, u8 rate)
+{
+        ide_hwif_t *hwif = drive->hwif;
+        const struct ide_port_ops *port_ops = hwif->port_ops;
+
+        if (port_ops == NULL || port_ops->set_dma_mode == NULL ||
+            (hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
+                return -1;
+
+        rate = ide_rate_filter(drive, rate);
+
+        BUG_ON(rate < XFER_PIO_0);
+
+        if (rate >= XFER_PIO_0 && rate <= XFER_PIO_5)
+                return ide_set_pio_mode(drive, rate);
+
+        return ide_set_dma_mode(drive, rate);
+}