Use dma_map_single() for a2091 driver (leave bounce buffer logic unchanged). Use dma_set_mask_and_coherent() to avoid explicit cache flushes. Compile-tested only. CC: linux-scsi@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/6d1d88ee-1cf6-c735-1e6d-bafd2096e322@xxxxxxxxx Signed-off-by: Michael Schmitz <schmitzmic@xxxxxxxxx> --- drivers/scsi/a2091.c | 53 +++++++++++++++++++++++++++++++++++--------- 1 file changed, 42 insertions(+), 11 deletions(-) diff --git a/drivers/scsi/a2091.c b/drivers/scsi/a2091.c index cf703a1ecdda..2338c75c34ed 100644 --- a/drivers/scsi/a2091.c +++ b/drivers/scsi/a2091.c @@ -24,8 +24,11 @@ struct a2091_hostdata { struct WD33C93_hostdata wh; struct a2091_scsiregs *regs; + struct device *dev; }; +#define DMA_DIR(d) ((d == DATA_OUT_DIR) ? DMA_TO_DEVICE : DMA_FROM_DEVICE) + static irqreturn_t a2091_intr(int irq, void *data) { struct Scsi_Host *instance = data; @@ -45,15 +48,31 @@ static irqreturn_t a2091_intr(int irq, void *data) static int dma_setup(struct scsi_cmnd *cmd, int dir_in) { struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(cmd); + unsigned long len = scsi_pointer->this_residual; struct Scsi_Host *instance = cmd->device->host; struct a2091_hostdata *hdata = shost_priv(instance); struct WD33C93_hostdata *wh = &hdata->wh; struct a2091_scsiregs *regs = hdata->regs; unsigned short cntr = CNTR_PDMD | CNTR_INTEN; - unsigned long addr = virt_to_bus(scsi_pointer->ptr); + dma_addr_t addr; + + addr = dma_map_single(hdata->dev, scsi_pointer->ptr, + len, DMA_DIR(dir_in)); + if (dma_mapping_error(hdata->dev, addr)) { + dev_warn(hdata->dev, "cannot map SCSI data block %p\n", + scsi_pointer->ptr); + return 1; + } + scsi_pointer->dma_handle = addr; /* don't allow DMA if the physical address is bad */ if (addr & A2091_XFER_MASK) { + /* drop useless mapping */ + dma_unmap_single(hdata->dev, scsi_pointer->dma_handle, + scsi_pointer->this_residual, + DMA_DIR(dir_in)); + scsi_pointer->dma_handle = (dma_addr_t) NULL; + wh->dma_bounce_len = (scsi_pointer->this_residual + 511) & ~0x1ff; wh->dma_bounce_buffer = kmalloc(wh->dma_bounce_len, GFP_KERNEL); @@ -64,9 +83,6 @@ static int dma_setup(struct scsi_cmnd *cmd, int dir_in) return 1; } - /* get the physical address of the bounce buffer */ - addr = virt_to_bus(wh->dma_bounce_buffer); - /* the bounce buffer may not be in the first 16M of physmem */ if (addr & A2091_XFER_MASK) { /* we could use chipmem... maybe later */ @@ -81,6 +97,17 @@ static int dma_setup(struct scsi_cmnd *cmd, int dir_in) memcpy(wh->dma_bounce_buffer, scsi_pointer->ptr, scsi_pointer->this_residual); } + + /* may flush/invalidate cache for us */ + addr = dma_map_single(hdata->dev, wh->dma_bounce_buffer, + wh->dma_bounce_len, DMA_DIR(dir_in)); + /* can't map buffer; use PIO */ + if (dma_mapping_error(hdata->dev, addr)) { + dev_warn(hdata->dev, "cannot map bounce buffer %p\n", + wh->dma_bounce_buffer); + return 1; + } + scsi_pointer->dma_handle = addr; } /* setup dma direction */ @@ -95,13 +122,8 @@ static int dma_setup(struct scsi_cmnd *cmd, int dir_in) /* setup DMA *physical* address */ regs->ACR = addr; - if (dir_in) { - /* invalidate any cache */ - cache_clear(addr, scsi_pointer->this_residual); - } else { - /* push any dirty cache */ - cache_push(addr, scsi_pointer->this_residual); - } + /* no more cache flush here - using coherent DMA alloc */ + /* start DMA */ regs->ST_DMA = 1; @@ -151,6 +173,9 @@ static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt, wh->dma_bounce_buffer = NULL; wh->dma_bounce_len = 0; } + dma_unmap_single(hdata->dev, scsi_pointer->dma_handle, + scsi_pointer->this_residual, + DMA_DIR(wh->dma_dir)); } static struct scsi_host_template a2091_scsi_template = { @@ -178,6 +203,11 @@ static int a2091_probe(struct zorro_dev *z, const struct zorro_device_id *ent) wd33c93_regs wdregs; struct a2091_hostdata *hdata; + if (dma_set_mask_and_coherent(&z->dev, DMA_BIT_MASK(24))) { + dev_warn(&z->dev, "cannot use 24 bit DMA\n"); + return -ENODEV; + } + if (!request_mem_region(z->resource.start, 256, "wd33c93")) return -EBUSY; @@ -198,6 +228,7 @@ static int a2091_probe(struct zorro_dev *z, const struct zorro_device_id *ent) wdregs.SCMD = ®s->SCMD; hdata = shost_priv(instance); + hdata->dev = &z->dev; hdata->wh.no_sync = 0xff; hdata->wh.fast = 0; hdata->wh.dma_mode = CTRL_DMA; -- 2.17.1
