[U-Boot] [PATCH] nvme: add more cache flushes

[Patrick Wildt <patrick@blueri.se>]

On an i.MX8MQ our nvme driver doesn't completely work since we are
missing a few cache flushes.  One is the prp list, which is an extra
buffer that we need to flush before handing it to the hardware.  Also
the block read/write operations needs more cache flushes on this SoC.

Signed-off-by: Patrick Wildt <patrick@blueri.se>
---
 drivers/nvme/nvme.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/nvme.c b/drivers/nvme/nvme.c
index 2444e0270f..69d5e3eedc 100644
--- a/drivers/nvme/nvme.c
+++ b/drivers/nvme/nvme.c
@@ -123,6 +123,9 @@ static int nvme_setup_prps(struct nvme_dev *dev, u64 *prp2,
 	}
 	*prp2 = (ulong)dev->prp_pool;
 
+	flush_dcache_range((ulong)dev->prp_pool, (ulong)dev->prp_pool +
+			   dev->prp_entry_num * sizeof(u64));
+
 	return 0;
 }
 
@@ -717,9 +720,10 @@ static ulong nvme_blk_rw(struct udevice *udev, lbaint_t blknr,
 	u16 lbas = 1 << (dev->max_transfer_shift - ns->lba_shift);
 	u64 total_lbas = blkcnt;
 
-	if (!read)
-		flush_dcache_range((unsigned long)buffer,
-				   (unsigned long)buffer + total_len);
+	flush_dcache_range((unsigned long)buffer,
+			   (unsigned long)buffer + total_len);
+	invalidate_dcache_range((unsigned long)buffer,
+				(unsigned long)buffer + total_len);
 
 	c.rw.opcode = read ? nvme_cmd_read : nvme_cmd_write;
 	c.rw.flags = 0;
@@ -755,9 +759,8 @@ static ulong nvme_blk_rw(struct udevice *udev, lbaint_t blknr,
 		buffer += lbas << ns->lba_shift;
 	}
 
-	if (read)
-		invalidate_dcache_range((unsigned long)buffer,
-					(unsigned long)buffer + total_len);
+	invalidate_dcache_range((unsigned long)buffer,
+				(unsigned long)buffer + total_len);
 
 	return (total_len - temp_len) >> desc->log2blksz;
 }
-- 
2.23.0