staging: ccree: handle limiting of DMA masks

Properly handle limiting of DMA masks based on device and bus
capabilities.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 20 insertions, 5 deletions

diff --git a/drivers/staging/ccree/ssi_driver.c b/drivers/staging/ccree/ssi_driver.c
index 5f03c2596f45..1d4c7bb78884 100644
--- a/drivers/staging/ccree/ssi_driver.c
+++ b/drivers/staging/ccree/ssi_driver.c
@@ -208,6 +208,7 @@ static int init_cc_resources(struct platform_device *plat_dev)
         struct device *dev = &plat_dev->dev;
         struct device_node *np = dev->of_node;
         u32 signature_val;
+        dma_addr_t dma_mask;
         int rc = 0;
 
         new_drvdata = devm_kzalloc(dev, sizeof(*new_drvdata), GFP_KERNEL);
@@ -256,15 +257,29 @@ static int init_cc_resources(struct platform_device *plat_dev)
         }
         dev_dbg(dev, "Registered to IRQ: %d\n", new_drvdata->irq);
 
+        if (!plat_dev->dev.dma_mask)
+                plat_dev->dev.dma_mask = &plat_dev->dev.coherent_dma_mask;
+
+        dma_mask = (dma_addr_t)(DMA_BIT_MASK(DMA_BIT_MASK_LEN));
+        while (dma_mask > 0x7fffffffUL) {
+                if (dma_supported(&plat_dev->dev, dma_mask)) {
+                        rc = dma_set_coherent_mask(&plat_dev->dev, dma_mask);
+                        if (!rc)
+                                break;
+                }
+                dma_mask >>= 1;
+        }
+
+        if (rc) {
+                dev_err(dev, "Error: failed in dma_set_mask, mask=%par\n",
+                        &dma_mask);
+                goto post_drvdata_err;
+        }
+
         rc = cc_clk_on(new_drvdata);
         if (rc)
                 goto post_drvdata_err;
 
-        if (!dev->dma_mask)
-                dev->dma_mask = &dev->coherent_dma_mask;
-
-        if (!dev->coherent_dma_mask)
-                dev->coherent_dma_mask = DMA_BIT_MASK(DMA_BIT_MASK_LEN);
 
         /* Verify correct mapping */
         signature_val = CC_HAL_READ_REGISTER(CC_REG_OFFSET(HOST_RGF, HOST_SIGNATURE));