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-rw-r--r--drivers/scsi/libata-core.c149
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 09639e7aaa7..9269fd9b814 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -1538,6 +1538,152 @@ void ata_port_disable(struct ata_port *ap)
ap->flags |= ATA_FLAG_PORT_DISABLED;
}
+/*
+ * This mode timing computation functionality is ported over from
+ * drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
+ */
+/*
+ * PIO 0-5, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
+ * These were taken from ATA/ATAPI-6 standard, rev 0a, except
+ * for PIO 5, which is a nonstandard extension and UDMA6, which
+ * is currently supported only by Maxtor drives.
+ */
+
+static const struct ata_timing ata_timing[] = {
+
+ { XFER_UDMA_6, 0, 0, 0, 0, 0, 0, 0, 15 },
+ { XFER_UDMA_5, 0, 0, 0, 0, 0, 0, 0, 20 },
+ { XFER_UDMA_4, 0, 0, 0, 0, 0, 0, 0, 30 },
+ { XFER_UDMA_3, 0, 0, 0, 0, 0, 0, 0, 45 },
+
+ { XFER_UDMA_2, 0, 0, 0, 0, 0, 0, 0, 60 },
+ { XFER_UDMA_1, 0, 0, 0, 0, 0, 0, 0, 80 },
+ { XFER_UDMA_0, 0, 0, 0, 0, 0, 0, 0, 120 },
+
+/* { XFER_UDMA_SLOW, 0, 0, 0, 0, 0, 0, 0, 150 }, */
+
+ { XFER_MW_DMA_2, 25, 0, 0, 0, 70, 25, 120, 0 },
+ { XFER_MW_DMA_1, 45, 0, 0, 0, 80, 50, 150, 0 },
+ { XFER_MW_DMA_0, 60, 0, 0, 0, 215, 215, 480, 0 },
+
+ { XFER_SW_DMA_2, 60, 0, 0, 0, 120, 120, 240, 0 },
+ { XFER_SW_DMA_1, 90, 0, 0, 0, 240, 240, 480, 0 },
+ { XFER_SW_DMA_0, 120, 0, 0, 0, 480, 480, 960, 0 },
+
+/* { XFER_PIO_5, 20, 50, 30, 100, 50, 30, 100, 0 }, */
+ { XFER_PIO_4, 25, 70, 25, 120, 70, 25, 120, 0 },
+ { XFER_PIO_3, 30, 80, 70, 180, 80, 70, 180, 0 },
+
+ { XFER_PIO_2, 30, 290, 40, 330, 100, 90, 240, 0 },
+ { XFER_PIO_1, 50, 290, 93, 383, 125, 100, 383, 0 },
+ { XFER_PIO_0, 70, 290, 240, 600, 165, 150, 600, 0 },
+
+/* { XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 960, 0 }, */
+
+ { 0xFF }
+};
+
+#define ENOUGH(v,unit) (((v)-1)/(unit)+1)
+#define EZ(v,unit) ((v)?ENOUGH(v,unit):0)
+
+static void ata_timing_quantize(const struct ata_timing *t, struct ata_timing *q, int T, int UT)
+{
+ q->setup = EZ(t->setup * 1000, T);
+ q->act8b = EZ(t->act8b * 1000, T);
+ q->rec8b = EZ(t->rec8b * 1000, T);
+ q->cyc8b = EZ(t->cyc8b * 1000, T);
+ q->active = EZ(t->active * 1000, T);
+ q->recover = EZ(t->recover * 1000, T);
+ q->cycle = EZ(t->cycle * 1000, T);
+ q->udma = EZ(t->udma * 1000, UT);
+}
+
+void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b,
+ struct ata_timing *m, unsigned int what)
+{
+ if (what & ATA_TIMING_SETUP ) m->setup = max(a->setup, b->setup);
+ if (what & ATA_TIMING_ACT8B ) m->act8b = max(a->act8b, b->act8b);
+ if (what & ATA_TIMING_REC8B ) m->rec8b = max(a->rec8b, b->rec8b);
+ if (what & ATA_TIMING_CYC8B ) m->cyc8b = max(a->cyc8b, b->cyc8b);
+ if (what & ATA_TIMING_ACTIVE ) m->active = max(a->active, b->active);
+ if (what & ATA_TIMING_RECOVER) m->recover = max(a->recover, b->recover);
+ if (what & ATA_TIMING_CYCLE ) m->cycle = max(a->cycle, b->cycle);
+ if (what & ATA_TIMING_UDMA ) m->udma = max(a->udma, b->udma);
+}
+
+static const struct ata_timing* ata_timing_find_mode(unsigned short speed)
+{
+ const struct ata_timing *t;
+
+ for (t = ata_timing; t->mode != speed; t++)
+ if (t->mode != 0xFF)
+ return NULL;
+ return t;
+}
+
+int ata_timing_compute(struct ata_device *adev, unsigned short speed,
+ struct ata_timing *t, int T, int UT)
+{
+ const struct ata_timing *s;
+ struct ata_timing p;
+
+ /*
+ * Find the mode.
+ */
+
+ if (!(s = ata_timing_find_mode(speed)))
+ return -EINVAL;
+
+ /*
+ * If the drive is an EIDE drive, it can tell us it needs extended
+ * PIO/MW_DMA cycle timing.
+ */
+
+ if (adev->id[ATA_ID_FIELD_VALID] & 2) { /* EIDE drive */
+ memset(&p, 0, sizeof(p));
+ if(speed >= XFER_PIO_0 && speed <= XFER_SW_DMA_0) {
+ if (speed <= XFER_PIO_2) p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO];
+ else p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO_IORDY];
+ } else if(speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2) {
+ p.cycle = adev->id[ATA_ID_EIDE_DMA_MIN];
+ }
+ ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
+ }
+
+ /*
+ * Convert the timing to bus clock counts.
+ */
+
+ ata_timing_quantize(s, t, T, UT);
+
+ /*
+ * Even in DMA/UDMA modes we still use PIO access for IDENTIFY, S.M.A.R.T
+ * and some other commands. We have to ensure that the DMA cycle timing is
+ * slower/equal than the fastest PIO timing.
+ */
+
+ if (speed > XFER_PIO_4) {
+ ata_timing_compute(adev, adev->pio_mode, &p, T, UT);
+ ata_timing_merge(&p, t, t, ATA_TIMING_ALL);
+ }
+
+ /*
+ * Lenghten active & recovery time so that cycle time is correct.
+ */
+
+ if (t->act8b + t->rec8b < t->cyc8b) {
+ t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
+ t->rec8b = t->cyc8b - t->act8b;
+ }
+
+ if (t->active + t->recover < t->cycle) {
+ t->active += (t->cycle - (t->active + t->recover)) / 2;
+ t->recover = t->cycle - t->active;
+ }
+
+ return 0;
+}
+
static struct {
unsigned int shift;
u8 base;
@@ -4764,6 +4910,9 @@ EXPORT_SYMBOL_GPL(ata_dev_id_string);
EXPORT_SYMBOL_GPL(ata_dev_config);
EXPORT_SYMBOL_GPL(ata_scsi_simulate);
+EXPORT_SYMBOL_GPL(ata_timing_compute);
+EXPORT_SYMBOL_GPL(ata_timing_merge);
+
#ifdef CONFIG_PCI
EXPORT_SYMBOL_GPL(pci_test_config_bits);
EXPORT_SYMBOL_GPL(ata_pci_host_stop);