[PATCH 15/20] mci: dw_mmc: enable use on 64-bit CPUs

[Ahmad Fatoum]

Provided that all DMA addresses can be safely truncated to 32-bit, the
driver is already usable on 64-bit CPUs. Silence the warnings and add
a check to ensure that coherent DMA addresses are indeed 32-bit.

arch code will need to make sure that dma_alloc() returns DMA memory
suitable for all DMA masters.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 drivers/mci/dw_mmc.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/mci/dw_mmc.c b/drivers/mci/dw_mmc.c
index 7979568841fc..db8aa9473458 100644
--- a/drivers/mci/dw_mmc.c
+++ b/drivers/mci/dw_mmc.c
@@ -124,12 +124,12 @@ static int dwmci_prepare_data_dma(struct dwmci_host *host,
 
 	dwmci_wait_reset(host, DWMCI_CTRL_FIFO_RESET);
 
-	dwmci_writel(host, DWMCI_DBADDR, (uint32_t)desc);
+	dwmci_writel(host, DWMCI_DBADDR, virt_to_phys(desc));
 
 	if (data->flags & MMC_DATA_READ)
-		start_addr = (uint32_t)data->dest;
+		start_addr = virt_to_phys(data->dest);
 	else
-		start_addr = (uint32_t)data->src;
+		start_addr = virt_to_phys((void *)data->src);
 
 	do {
 		flags = DWMCI_IDMAC_OWN | DWMCI_IDMAC_CH;
@@ -145,7 +145,7 @@ static int dwmci_prepare_data_dma(struct dwmci_host *host,
 		desc->flags = flags;
 		desc->cnt = cnt;
 		desc->addr = start_addr + (i * PAGE_SIZE);
-		desc->next_addr = (uint32_t)(desc + 1);
+		desc->next_addr = virt_to_phys(desc + 1);
 
 		dev_dbg(host->mci.hw_dev, "desc@ 0x%p 0x%08x 0x%08x 0x%08x 0x%08x\n",
 				desc, flags, cnt, desc->addr, desc->next_addr);
@@ -290,10 +290,10 @@ dwmci_cmd(struct mci_host *mci, struct mci_cmd *cmd, struct mci_data *data)
 		num_bytes = data->blocks * data->blocksize;
 
 		if (data->flags & MMC_DATA_WRITE)
-			dma_sync_single_for_device((unsigned long)data->src,
+			dma_sync_single_for_device(virt_to_phys((void *)data->src),
 						   num_bytes, DMA_TO_DEVICE);
 		else
-			dma_sync_single_for_device((unsigned long)data->dest,
+			dma_sync_single_for_device(virt_to_phys(data->dest),
 						   num_bytes, DMA_FROM_DEVICE);
 
 		ret = dwmci_prepare_data(host, data);
@@ -400,10 +400,10 @@ dwmci_cmd(struct mci_host *mci, struct mci_cmd *cmd, struct mci_data *data)
 			dwmci_writel(host, DWMCI_CTRL, ctrl);
 
 			if (data->flags & MMC_DATA_WRITE)
-				dma_sync_single_for_cpu((unsigned long)data->src,
+				dma_sync_single_for_cpu(virt_to_phys((void *)data->src),
 							num_bytes, DMA_TO_DEVICE);
 			else
-				dma_sync_single_for_cpu((unsigned long)data->dest,
+				dma_sync_single_for_cpu(virt_to_phys(data->dest),
 							num_bytes, DMA_FROM_DEVICE);
 		}
 	}
@@ -547,6 +547,9 @@ static int dw_mmc_probe(struct device_d *dev)
 	struct resource *iores;
 	struct dwmci_host *host;
 	struct dw_mmc_platform_data *pdata = dev->platform_data;
+	dma_addr_t idmac;
+
+	dma_set_mask(dev, DMA_BIT_MASK(32));
 
 	host = xzalloc(sizeof(*host));
 
@@ -567,7 +570,12 @@ static int dw_mmc_probe(struct device_d *dev)
 	host->ioaddr = IOMEM(iores->start);
 
 	host->idmac = dma_alloc_coherent(sizeof(*host->idmac) * DW_MMC_NUM_IDMACS,
-					 DMA_ADDRESS_BROKEN);
+					 &idmac); /* still DMA_ADDRESS_BROKEN */
+
+	if (dma_mapping_error(dev, idmac)) {
+		dev_err(dev, "allocated buffer violates DMA mask\n");
+		return -ENOMEM;
+	}
 
 	host->mci.send_cmd = dwmci_cmd;
 	host->mci.set_ios = dwmci_set_ios;
-- 
2.29.2