Commit 158da6bc authored by Michael Schmitz's avatar Michael Schmitz Committed by Martin K. Petersen
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scsi: gvp11: Convert m68k WD33C93 drivers to DMA API 

Use dma_map_single() for gvp11 driver (leave bounce buffer logic
unchanged).

Use dma_set_mask_and_coherent() to avoid explicit cache flushes.

Compile-tested only.

CC: linux-scsi@vger.kernel.org
Link: https://lore.kernel.org/r/6d1d88ee-1cf6-c735-1e6d-bafd2096e322@gmail.com
Link: https://lore.kernel.org/r/20220630033302.3183-4-schmitzmic@gmail.com


Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>

--

Changes from v1:

Arnd Bergmann:
- reorder bounce buffer copy and dma mapping
parent 479accbb

drivers/scsi/gvp11.c

+77 −18
Original line number Diff line number Diff line
@@ -26,8 +26,12 @@ 
struct gvp11_hostdata {

	struct WD33C93_hostdata wh;

	struct gvp11_scsiregs *regs;

	struct device *dev;

};



#define DMA_DIR(d)   ((d == DATA_OUT_DIR) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)

#define TO_DMA_MASK(m)	((~(m & 0xfffffff0))-1)



static irqreturn_t gvp11_intr(int irq, void *data)

{

	struct Scsi_Host *instance = data;
@@ -54,17 +58,33 @@ void gvp11_setup(char *str, int *ints) 
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 gvp11_hostdata *hdata = shost_priv(instance);

	struct WD33C93_hostdata *wh = &hdata->wh;

	struct gvp11_scsiregs *regs = hdata->regs;

	unsigned short cntr = GVP11_DMAC_INT_ENABLE;

	unsigned long addr = virt_to_bus(scsi_pointer->ptr);

	dma_addr_t addr;

	int bank_mask;

	static int scsi_alloc_out_of_range = 0;



	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;



	/* use bounce buffer if the physical address is bad */

	if (addr & wh->dma_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;



		if (!scsi_alloc_out_of_range) {
@@ -87,10 +107,32 @@ static int dma_setup(struct scsi_cmnd *cmd, int dir_in) 
			wh->dma_buffer_pool = BUF_CHIP_ALLOCED;

		}



		/* check if the address of the bounce buffer is OK */

		addr = virt_to_bus(wh->dma_bounce_buffer);

		if (!dir_in) {

			/* copy to bounce buffer for a write */

			memcpy(wh->dma_bounce_buffer, scsi_pointer->ptr,

			       scsi_pointer->this_residual);

		}



		if (wh->dma_buffer_pool == BUF_SCSI_ALLOCED) {

		/* will 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;

			}

		}



		if (addr & wh->dma_xfer_mask) {

			/* drop useless mapping */

			dma_unmap_single(hdata->dev, scsi_pointer->dma_handle,

					 scsi_pointer->this_residual,

					 DMA_DIR(dir_in));

			/* fall back to Chip RAM if address out of range */

			if (wh->dma_buffer_pool == BUF_SCSI_ALLOCED) {

				kfree(wh->dma_bounce_buffer);
@@ -108,15 +150,19 @@ static int dma_setup(struct scsi_cmnd *cmd, int dir_in) 
				return 1;

			}



			addr = virt_to_bus(wh->dma_bounce_buffer);

			wh->dma_buffer_pool = BUF_CHIP_ALLOCED;

		}



			if (!dir_in) {

				/* copy to bounce buffer for a write */

				memcpy(wh->dma_bounce_buffer, scsi_pointer->ptr,

				       scsi_pointer->this_residual);

			}

			/* chip RAM can be mapped to phys. address directly */

			addr = virt_to_phys(wh->dma_bounce_buffer);

			/* no need to flush/invalidate cache */

			wh->dma_buffer_pool = BUF_CHIP_ALLOCED;

		}

		/* finally, have OK mapping (punted for PIO else) */

		scsi_pointer->dma_handle = addr;



	}



	/* setup dma direction */
@@ -129,13 +175,7 @@ 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 - dma_map_single() takes care */



	bank_mask = (~wh->dma_xfer_mask >> 18) & 0x01c0;

	if (bank_mask)
@@ -161,6 +201,11 @@ static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt, 
	/* remove write bit from CONTROL bits */

	regs->CNTR = GVP11_DMAC_INT_ENABLE;



	if (wh->dma_buffer_pool == BUF_SCSI_ALLOCED)

		dma_unmap_single(hdata->dev, scsi_pointer->dma_handle,

				 scsi_pointer->this_residual,

				 DMA_DIR(wh->dma_dir));



	/* copy from a bounce buffer, if necessary */

	if (status && wh->dma_bounce_buffer) {

		if (wh->dma_dir && SCpnt)
@@ -287,6 +332,13 @@ static int gvp11_probe(struct zorro_dev *z, const struct zorro_device_id *ent) 


	default_dma_xfer_mask = ent->driver_data;



	if (dma_set_mask_and_coherent(&z->dev,

		TO_DMA_MASK(default_dma_xfer_mask))) {

		dev_warn(&z->dev, "cannot use DMA mask %x\n",

			 TO_DMA_MASK(default_dma_xfer_mask));

		return -ENODEV;

	}



	/*

	 * Rumors state that some GVP ram boards use the same product

	 * code as the SCSI controllers. Therefore if the board-size
@@ -327,9 +379,16 @@ static int gvp11_probe(struct zorro_dev *z, const struct zorro_device_id *ent) 
	wdregs.SCMD = &regs->SCMD;



	hdata = shost_priv(instance);

	if (gvp11_xfer_mask)

	if (gvp11_xfer_mask) {

		hdata->wh.dma_xfer_mask = gvp11_xfer_mask;

	else

		if (dma_set_mask_and_coherent(&z->dev,

			TO_DMA_MASK(gvp11_xfer_mask))) {

			dev_warn(&z->dev, "cannot use DMA mask %x\n",

				 TO_DMA_MASK(gvp11_xfer_mask));

			error = -ENODEV;

			goto fail_check_or_alloc;

		}

	} else

		hdata->wh.dma_xfer_mask = default_dma_xfer_mask;



	hdata->wh.no_sync = 0xff;