habanalabs: keep track of the device's dma mask

This patch refactors the code that is responsible to set the DMA mask for
the device.

Upon each change of the dma mask, the driver will save the new value that
was set. This is needed in order to make sure we don't try to increase the
mask a second time, in case we failed in the first time. This is
especially relevant for Power machines, as that may cause a change in
configuration of the TVT which will break the device.

Goya will first try to set the device's dma mask to 39 bits, so that the
memory that is allocated on the host machine for communication with the
device's cpu will be in a bus address which is lower then 39 bits. Later,
Goya will try to increase that mask to 48 bits, but only if setting the
mask to 39 bits was successful.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

1 files changed, 10 insertions, 22 deletions

diff --git a/drivers/misc/habanalabs/goya/goya.c b/drivers/misc/habanalabs/goya/goya.c
index 630979422390..c69f3b928350 100644
--- a/drivers/misc/habanalabs/goya/goya.c
+++ b/drivers/misc/habanalabs/goya/goya.c
@@ -482,7 +482,7 @@ static int goya_early_init(struct hl_device *hdev)
 
 	prop->dram_pci_bar_size = pci_resource_len(pdev, DDR_BAR_ID);
 
-	rc = hl_pci_init(hdev);
+	rc = hl_pci_init(hdev, 39);
 	if (rc)
 		return rc;
 
@@ -2445,28 +2445,16 @@ static int goya_hw_init(struct hl_device *hdev)
 		goto disable_msix;
 	}
 
-	/* CPU initialization is finished, we can now move to 48 bit DMA mask */
-	rc = pci_set_dma_mask(hdev->pdev, DMA_BIT_MASK(48));
-	if (rc) {
-		dev_warn(hdev->dev, "Unable to set pci dma mask to 48 bits\n");
-		rc = pci_set_dma_mask(hdev->pdev, DMA_BIT_MASK(32));
-		if (rc) {
-			dev_err(hdev->dev,
-				"Unable to set pci dma mask to 32 bits\n");
-			goto disable_pci_access;
-		}
-	}
-
-	rc = pci_set_consistent_dma_mask(hdev->pdev, DMA_BIT_MASK(48));
-	if (rc) {
-		dev_warn(hdev->dev,
-			"Unable to set pci consistent dma mask to 48 bits\n");
-		rc = pci_set_consistent_dma_mask(hdev->pdev, DMA_BIT_MASK(32));
-		if (rc) {
-			dev_err(hdev->dev,
-				"Unable to set pci consistent dma mask to 32 bits\n");
+	/*
+	 * Check if we managed to set the DMA mask to more then 32 bits. If so,
+	 * let's try to increase it again because in Goya we set the initial
+	 * dma mask to less then 39 bits so that the allocation of the memory
+	 * area for the device's cpu will be under 39 bits
+	 */
+	if (hdev->dma_mask > 32) {
+		rc = hl_pci_set_dma_mask(hdev, 48);
+		if (rc)
 			goto disable_pci_access;
-		}
 	}
 
 	/* Perform read from the device to flush all MSI-X configuration */