spi: spi-zynqmp-gqspi: return -ENOMEM if dma_map_single fails

The spi controller supports 44-bit address space on AXI in DMA mode,
so set dma_addr_t width to 44-bit to avoid using a swiotlb mapping.
In addition, if dma_map_single fails, it should return immediately
instead of continuing doing the DMA operation which bases on invalid
address.

This fixes the following crash which occurs in reading a big block
from flash:

[ 123.633577] zynqmp-qspi ff0f0000.spi: swiotlb buffer is full (sz: 4194304 bytes), total 32768 (slots), used 0 (slots)
[ 123.644230] zynqmp-qspi ff0f0000.spi: ERR:rxdma:memory not mapped
[ 123.784625] Unable to handle kernel paging request at virtual address 00000000003fffc0
[ 123.792536] Mem abort info:
[ 123.795313] ESR = 0x96000145
[ 123.798351] EC = 0x25: DABT (current EL), IL = 32 bits
[ 123.803655] SET = 0, FnV = 0
[ 123.806693] EA = 0, S1PTW = 0
[ 123.809818] Data abort info:
[ 123.812683] ISV = 0, ISS = 0x00000145
[ 123.816503] CM = 1, WnR = 1
[ 123.819455] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000805047000
[ 123.825887] [00000000003fffc0] pgd=0000000803b45003, p4d=0000000803b45003, pud=0000000000000000
[ 123.834586] Internal error: Oops: 96000145 [#1] PREEMPT SMP

Fixes: 1c26372e5aa9 ("spi: spi-zynqmp-gqspi: Update driver to use spi-mem framework")
Signed-off-by: Quanyang Wang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/spi/spi-zynqmp-gqspi.c

···
  * zynqmp_qspi_setuprxdma - This function sets up the RX DMA operation
  * @xqspi:	xqspi is a pointer to the GQSPI instance.
  */
-static void zynqmp_qspi_setuprxdma(struct zynqmp_qspi *xqspi)
+static int zynqmp_qspi_setuprxdma(struct zynqmp_qspi *xqspi)
 {
 	u32 rx_bytes, rx_rem, config_reg;
 	dma_addr_t addr;
···
 		zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
 		xqspi->mode = GQSPI_MODE_IO;
 		xqspi->dma_rx_bytes = 0;
-		return;
+		return 0;
 	}
 
 	rx_rem = xqspi->bytes_to_receive % 4;
···
 
 	addr = dma_map_single(xqspi->dev, (void *)xqspi->rxbuf,
 			      rx_bytes, DMA_FROM_DEVICE);
-	if (dma_mapping_error(xqspi->dev, addr))
+	if (dma_mapping_error(xqspi->dev, addr)) {
 		dev_err(xqspi->dev, "ERR:rxdma:memory not mapped\n");
+		return -ENOMEM;
+	}
 
 	xqspi->dma_rx_bytes = rx_bytes;
 	xqspi->dma_addr = addr;
···
 
 	/* Write the number of bytes to transfer */
 	zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_SIZE_OFST, rx_bytes);
+
+	return 0;
 }
 
 /**
···
  * @genfifoentry:	genfifoentry is pointer to the variable in which
  *			GENFIFO	mask is returned to calling function
  */
-static void zynqmp_qspi_read_op(struct zynqmp_qspi *xqspi, u8 rx_nbits,
+static int zynqmp_qspi_read_op(struct zynqmp_qspi *xqspi, u8 rx_nbits,
 				u32 genfifoentry)
 {
-	zynqmp_qspi_setuprxdma(xqspi);
+	int ret;
+
+	ret = zynqmp_qspi_setuprxdma(xqspi);
+	if (ret)
+		return ret;
 	zynqmp_qspi_fillgenfifo(xqspi, rx_nbits, genfifoentry);
+
+	return 0;
 }
 
 /**
···
 			xqspi->rxbuf = (u8 *)op->data.buf.in;
 			xqspi->bytes_to_receive = op->data.nbytes;
 			xqspi->bytes_to_transfer = 0;
-			zynqmp_qspi_read_op(xqspi, op->data.buswidth,
+			err = zynqmp_qspi_read_op(xqspi, op->data.buswidth,
 					    genfifoentry);
+			if (err)
+				goto return_err;
+
 			zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
 					   zynqmp_gqspi_read
 					   (xqspi, GQSPI_CONFIG_OFST) |
···
 		goto clk_dis_all;
 	}
 
+	dma_set_mask(&pdev->dev, DMA_BIT_MASK(44));
 	ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
 	ctlr->num_chipselect = GQSPI_DEFAULT_NUM_CS;
 	ctlr->mem_ops = &zynqmp_qspi_mem_ops;