habanalabs: helper function to validate export params

Validate export parameters in a dedicated function instead of in the
main export flow.
This will be useful later when support to export dmabuf for devices
with virtual memory will be added.
Signed-off-by: Ohad Sharabi <osharabi@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

drivers/misc/habanalabs/common/memory.c

@@ -1797,36 +1797,10 @@ static int export_dmabuf(struct hl_ctx *ctx,
 	return rc;
 }
 
-/**
- * export_dmabuf_from_addr() - export a dma-buf object for the given memory
- *                             address and size.
- * @ctx: pointer to the context structure.
- * @device_addr:  device memory physical address.
- * @size: size of device memory.
- * @flags: DMA-BUF file/FD flags.
- * @dmabuf_fd: pointer to result FD that represents the dma-buf object.
- *
- * Create and export a dma-buf object for an existing memory allocation inside
- * the device memory, and return a FD which is associated with the dma-buf
- * object.
- *
- * Return: 0 on success, non-zero for failure.
- */
-static int export_dmabuf_from_addr(struct hl_ctx *ctx, u64 device_addr,
-					u64 size, int flags, int *dmabuf_fd)
+static int validate_export_params(struct hl_device *hdev, u64 device_addr, u64 size)
 {
-	struct hl_dmabuf_priv *hl_dmabuf;
-	struct hl_device *hdev = ctx->hdev;
-	struct asic_fixed_properties *prop;
+	struct asic_fixed_properties *prop = &hdev->asic_prop;
 	u64 bar_address;
-	int rc;
-
-	prop = &hdev->asic_prop;
-
-	if (prop->dram_supports_virtual_memory) {
-		dev_dbg(hdev->dev, "Export not supported for devices with virtual memory\n");
-		return -EOPNOTSUPP;
-	}
 
 	if (!IS_ALIGNED(device_addr, PAGE_SIZE)) {
 		dev_dbg(hdev->dev,
@@ -1843,26 +1817,61 @@ static int export_dmabuf_from_addr(struct hl_ctx *ctx, u64 device_addr,
 	}
 
 	if (device_addr < prop->dram_user_base_address ||
-				device_addr + size > prop->dram_end_address ||
-				device_addr + size < device_addr) {
+				(device_addr + size) > prop->dram_end_address ||
+				(device_addr + size) < device_addr) {
 		dev_dbg(hdev->dev,
 			"DRAM memory range 0x%llx (+0x%llx) is outside of DRAM boundaries\n",
 			device_addr, size);
 		return -EINVAL;
 	}
 
-	bar_address = hdev->dram_pci_bar_start +
-			(device_addr - prop->dram_base_address);
+	bar_address = hdev->dram_pci_bar_start + (device_addr - prop->dram_base_address);
 
-	if (bar_address + size >
-			hdev->dram_pci_bar_start + prop->dram_pci_bar_size ||
-			bar_address + size < bar_address) {
+	if ((bar_address + size) > (hdev->dram_pci_bar_start + prop->dram_pci_bar_size) ||
+			(bar_address + size) < bar_address) {
 		dev_dbg(hdev->dev,
 			"DRAM memory range 0x%llx (+0x%llx) is outside of PCI BAR boundaries\n",
 			device_addr, size);
 		return -EINVAL;
 	}
 
+	return 0;
+}
+
+/**
+ * export_dmabuf_from_addr() - export a dma-buf object for the given memory
+ *                             address and size.
+ * @ctx: pointer to the context structure.
+ * @device_addr:  device memory physical address.
+ * @size: size of device memory.
+ * @flags: DMA-BUF file/FD flags.
+ * @dmabuf_fd: pointer to result FD that represents the dma-buf object.
+ *
+ * Create and export a dma-buf object for an existing memory allocation inside
+ * the device memory, and return a FD which is associated with the dma-buf
+ * object.
+ *
+ * Return: 0 on success, non-zero for failure.
+ */
+static int export_dmabuf_from_addr(struct hl_ctx *ctx, u64 device_addr,
+					u64 size, int flags, int *dmabuf_fd)
+{
+	struct hl_dmabuf_priv *hl_dmabuf;
+	struct hl_device *hdev = ctx->hdev;
+	struct asic_fixed_properties *prop;
+	int rc;
+
+	prop = &hdev->asic_prop;
+
+	if (prop->dram_supports_virtual_memory) {
+		dev_dbg(hdev->dev, "Export not supported for devices with virtual memory\n");
+		return -EOPNOTSUPP;
+	}
+
+	rc = validate_export_params(hdev, device_addr, size);
+	if (rc)
+		return rc;
+
 	hl_dmabuf = kzalloc(sizeof(*hl_dmabuf), GFP_KERNEL);
 	if (!hl_dmabuf)
 		return -ENOMEM;