On Thu, 11 Oct 2018, Christoph Hellwig wrote:
> index 90604bff8dd2..73fcbd65b9fe 100644
> --- a/drivers/scsi/esp_scsi.c
> +++ b/drivers/scsi/esp_scsi.c
> @@ -369,19 +369,25 @@ static void esp_map_dma(struct esp *esp, struct
> scsi_cmnd *cmd)
> {
> struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
> struct scatterlist *sg = scsi_sglist(cmd);
> - int dir = cmd->sc_data_direction;
> - int total, i;
> + int total = 0, i;
>
> - if (dir == DMA_NONE)
> - return;
> -
> - spriv->u.num_sg = esp->ops->map_sg(esp, sg, scsi_sg_count(cmd), dir);
> + if (esp->flags & ESP_FLAG_NO_DMA_MAP) {
> + /*
> + * For pseudo DMA and PIO we need the virtual address instead of
> + * a dma address, so perform an identity mapping.
> + */
> + spriv->u.num_sg = scsi_sg_count(cmd);
> + for (i = 0; i < spriv->u.num_sg; i++) {
> + sg[i].dma_address = (uintptr_t)sg_virt(&sg[i]);
> + total += sg_dma_len(&sg[i]);
> + }
> + } else {
> + spriv->u.num_sg = scsi_dma_map(cmd);
> + for (i = 0; i < spriv->u.num_sg; i++)
> + total += sg_dma_len(&sg[i]);
> + }
> spriv->cur_residue = sg_dma_len(sg);
> spriv->cur_sg = sg;
> -
> - total = 0;
> - for (i = 0; i < spriv->u.num_sg; i++)
> - total += sg_dma_len(&sg[i]);
> spriv->tot_residue = total;
> }
>
> @@ -441,13 +447,8 @@ static void esp_advance_dma(struct esp *esp, struct
> esp_cmd_entry *ent,
>
> static void esp_unmap_dma(struct esp *esp, struct scsi_cmnd *cmd)
> {
> - struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
> - int dir = cmd->sc_data_direction;
> -
> - if (dir == DMA_NONE)
> - return;
> -
> - esp->ops->unmap_sg(esp, scsi_sglist(cmd), spriv->u.num_sg, dir);
> + if (!(esp->flags & ESP_FLAG_NO_DMA_MAP))
> + scsi_dma_unmap(cmd);
> }
>
> static void esp_save_pointers(struct esp *esp, struct esp_cmd_entry *ent)
> @@ -624,6 +625,28 @@ static void esp_free_lun_tag(struct esp_cmd_entry *ent,
> }
> }
>
> +static void esp_map_sense(struct esp *esp, struct esp_cmd_entry *ent)
> +{
> + ent->sense_ptr = ent->cmd->sense_buffer;
> + if (esp->flags & ESP_FLAG_NO_DMA_MAP) {
> + ent->sense_dma = (uintptr_t)ent->sense_ptr;
> + return;
> + }
> +
> + ent->sense_dma = dma_map_single(esp->dev, ent->sense_ptr,
> + SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
> +}
> +
> +static void esp_unmap_sense(struct esp *esp, struct esp_cmd_entry *ent)
> +{
> + if (esp->flags & ESP_FLAG_NO_DMA_MAP)
> + return;
> +
> + dma_unmap_single(esp->dev, ent->sense_dma, SCSI_SENSE_BUFFERSIZE,
> + DMA_FROM_DEVICE);
> + ent->sense_ptr = NULL;
> +}
> +
I think it is better to clear ent->sense_ptr unconditionally, as before.
--
> /* When a contingent allegiance conditon is created, we force feed a
> * REQUEST_SENSE command to the device to fetch the sense data. I
> * tried many other schemes, relying on the scsi error handling layer
> @@ -645,12 +668,7 @@ static void esp_autosense(struct esp *esp, struct
> esp_cmd_entry *ent)
> if (!ent->sense_ptr) {
> esp_log_autosense("Doing auto-sense for tgt[%d] lun[%d]\n",
> tgt, lun);
> -
> - ent->sense_ptr = cmd->sense_buffer;
> - ent->sense_dma = esp->ops->map_single(esp,
> - ent->sense_ptr,
> - SCSI_SENSE_BUFFERSIZE,
> - DMA_FROM_DEVICE);
> + esp_map_sense(esp, ent);
> }
> ent->saved_sense_ptr = ent->sense_ptr;
>
> @@ -902,9 +920,7 @@ static void esp_cmd_is_done(struct esp *esp, struct
> esp_cmd_entry *ent,
> }
>
> if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
> - esp->ops->unmap_single(esp, ent->sense_dma,
> - SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
> - ent->sense_ptr = NULL;
> + esp_unmap_sense(esp, ent);
>
> /* Restore the message/status bytes to what we actually
> * saw originally. Also, report that we are providing
> @@ -1256,10 +1272,7 @@ static int esp_finish_select(struct esp *esp)
> esp->cmd_bytes_ptr = NULL;
> esp->cmd_bytes_left = 0;
> } else {
> - esp->ops->unmap_single(esp, ent->sense_dma,
> - SCSI_SENSE_BUFFERSIZE,
> - DMA_FROM_DEVICE);
> - ent->sense_ptr = NULL;
> + esp_unmap_sense(esp, ent);
> }
>
> /* Now that the state is unwound properly, put back onto
> @@ -2039,11 +2052,8 @@ static void esp_reset_cleanup_one(struct esp *esp,
> struct esp_cmd_entry *ent)
> esp_free_lun_tag(ent, cmd->device->hostdata);
> cmd->result = DID_RESET << 16;
>
> - if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
> - esp->ops->unmap_single(esp, ent->sense_dma,
> - SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
> - ent->sense_ptr = NULL;
> - }
> + if (ent->flags & ESP_CMD_FLAG_AUTOSENSE)
> + esp_unmap_sense(esp, ent);
>
> cmd->scsi_done(cmd);
> list_del(&ent->list);
