habanalabs: return old dram bar address upon change

This patch changes the ASIC interface function that changes the DRAM bar
window. The change is to return the old address that the DRAM bar pointed
to instead of an error code.

This simplifies the code that use this function (mainly in debugfs) to
restore the bar to the old setting.

This is also needed for easier support in future ASICs.

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

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/misc/habanalabs/habanalabs.h b/drivers/misc/habanalabs/habanalabs.h
index a624d1e1e1e5..65717e4055da 100644
--- a/drivers/misc/habanalabs/habanalabs.h
+++ b/drivers/misc/habanalabs/habanalabs.h
@@ -487,7 +487,8 @@ enum hl_pll_frequency {
  * @send_cpu_message: send buffer to ArmCP.
  * @get_hw_state: retrieve the H/W state
  * @pci_bars_map: Map PCI BARs.
- * @set_dram_bar_base: Set DRAM BAR to map specific device address.
+ * @set_dram_bar_base: Set DRAM BAR to map specific device address. Returns
+ *                     old address the bar pointed to or U64_MAX for failure
  * @init_iatu: Initialize the iATU unit inside the PCI controller.
  * @rreg: Read a register. Needed for simulator support.
  * @wreg: Write a register. Needed for simulator support.
@@ -564,7 +565,7 @@ struct hl_asic_funcs {
 				u16 len, u32 timeout, long *result);
 	enum hl_device_hw_state (*get_hw_state)(struct hl_device *hdev);
 	int (*pci_bars_map)(struct hl_device *hdev);
-	int (*set_dram_bar_base)(struct hl_device *hdev, u64 addr);
+	u64 (*set_dram_bar_base)(struct hl_device *hdev, u64 addr);
 	int (*init_iatu)(struct hl_device *hdev);
 	u32 (*rreg)(struct hl_device *hdev, u32 reg);
 	void (*wreg)(struct hl_device *hdev, u32 reg, u32 val);