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-rw-r--r--drivers/dma/ioat/init.c27
-rw-r--r--drivers/dma/ioat/registers.h14
2 files changed, 41 insertions, 0 deletions
diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c
index 020bcdecb3fb..d41dc9a9ff68 100644
--- a/drivers/dma/ioat/init.c
+++ b/drivers/dma/ioat/init.c
@@ -638,6 +638,11 @@ static void ioat_free_chan_resources(struct dma_chan *c)
ioat_stop(ioat_chan);
ioat_reset_hw(ioat_chan);
+ /* Put LTR to idle */
+ if (ioat_dma->version >= IOAT_VER_3_4)
+ writeb(IOAT_CHAN_LTR_SWSEL_IDLE,
+ ioat_chan->reg_base + IOAT_CHAN_LTR_SWSEL_OFFSET);
+
spin_lock_bh(&ioat_chan->cleanup_lock);
spin_lock_bh(&ioat_chan->prep_lock);
descs = ioat_ring_space(ioat_chan);
@@ -727,6 +732,28 @@ static int ioat_alloc_chan_resources(struct dma_chan *c)
spin_unlock_bh(&ioat_chan->prep_lock);
spin_unlock_bh(&ioat_chan->cleanup_lock);
+ /* Setting up LTR values for 3.4 or later */
+ if (ioat_chan->ioat_dma->version >= IOAT_VER_3_4) {
+ u32 lat_val;
+
+ lat_val = IOAT_CHAN_LTR_ACTIVE_SNVAL |
+ IOAT_CHAN_LTR_ACTIVE_SNLATSCALE |
+ IOAT_CHAN_LTR_ACTIVE_SNREQMNT;
+ writel(lat_val, ioat_chan->reg_base +
+ IOAT_CHAN_LTR_ACTIVE_OFFSET);
+
+ lat_val = IOAT_CHAN_LTR_IDLE_SNVAL |
+ IOAT_CHAN_LTR_IDLE_SNLATSCALE |
+ IOAT_CHAN_LTR_IDLE_SNREQMNT;
+ writel(lat_val, ioat_chan->reg_base +
+ IOAT_CHAN_LTR_IDLE_OFFSET);
+
+ /* Select to active */
+ writeb(IOAT_CHAN_LTR_SWSEL_ACTIVE,
+ ioat_chan->reg_base +
+ IOAT_CHAN_LTR_SWSEL_OFFSET);
+ }
+
ioat_start_null_desc(ioat_chan);
/* check that we got off the ground */
diff --git a/drivers/dma/ioat/registers.h b/drivers/dma/ioat/registers.h
index 2b517d6db5fd..99c1c24d465d 100644
--- a/drivers/dma/ioat/registers.h
+++ b/drivers/dma/ioat/registers.h
@@ -253,4 +253,18 @@
#define IOAT_CHAN_DRS_EN 0x0100
#define IOAT_CHAN_DRS_AUTOWRAP 0x0200
+#define IOAT_CHAN_LTR_SWSEL_OFFSET 0xBC
+#define IOAT_CHAN_LTR_SWSEL_ACTIVE 0x0
+#define IOAT_CHAN_LTR_SWSEL_IDLE 0x1
+
+#define IOAT_CHAN_LTR_ACTIVE_OFFSET 0xC0
+#define IOAT_CHAN_LTR_ACTIVE_SNVAL 0x0000 /* 0 us */
+#define IOAT_CHAN_LTR_ACTIVE_SNLATSCALE 0x0800 /* 1us scale */
+#define IOAT_CHAN_LTR_ACTIVE_SNREQMNT 0x8000 /* snoop req enable */
+
+#define IOAT_CHAN_LTR_IDLE_OFFSET 0xC4
+#define IOAT_CHAN_LTR_IDLE_SNVAL 0x0258 /* 600 us */
+#define IOAT_CHAN_LTR_IDLE_SNLATSCALE 0x0800 /* 1us scale */
+#define IOAT_CHAN_LTR_IDLE_SNREQMNT 0x8000 /* snoop req enable */
+
#endif /* _IOAT_REGISTERS_H_ */