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

On Mon, Oct 14, 2019 at 7:11 PM Patrick Wildt patrick@blueri.se wrote:

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);
  

Why we need this for read?

•   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);
  

Why we need this for write?

    return (total_len - temp_len) >> desc->log2blksz;

}

Regards, Bin