habanalabs: skip read fw errors if dynamic descriptor invalid

[ Upstream commit 4fac990f604e6c10538026835a8a30f3c1b6fcf5 ]

Reporting FW errors involves reading of the error registers.

In case we have a corrupted FW descriptor we cannot do that since the
dynamic scratchpad is potentially corrupted as well and may cause kernel
crush when attempting access to a corrupted register offset.

Signed-off-by: Ohad Sharabi <osharabi@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/misc/habanalabs/common/firmware_if.c b/drivers/misc/habanalabs/common/firmware_if.c
index 8d2568c..a8e6839 100644 (file)
--- a/drivers/misc/habanalabs/common/firmware_if.c
+++ b/drivers/misc/habanalabs/common/firmware_if.c
@@ -1703,6 +1703,9 @@ static int hl_fw_dynamic_validate_descriptor(struct hl_device *hdev,
                return rc;
        }
 
+       /* here we can mark the descriptor as valid as the content has been validated */
+       fw_loader->dynamic_loader.fw_desc_valid = true;
+
        return 0;
 }
 
@@ -1759,7 +1762,13 @@ static int hl_fw_dynamic_read_and_validate_descriptor(struct hl_device *hdev,
                return rc;
        }
 
-       /* extract address copy the descriptor from */
+       /*
+        * extract address to copy the descriptor from
+        * in addition, as the descriptor value is going to be over-ridden by new data- we mark it
+        * as invalid.
+        * it will be marked again as valid once validated
+        */
+       fw_loader->dynamic_loader.fw_desc_valid = false;
        src = hdev->pcie_bar[region->bar_id] + region->offset_in_bar +
                                                        response->ram_offset;
        memcpy_fromio(fw_desc, src, sizeof(struct lkd_fw_comms_desc));
@@ -2239,6 +2248,9 @@ static int hl_fw_dynamic_init_cpu(struct hl_device *hdev,
        dev_info(hdev->dev,
                "Loading firmware to device, may take some time...\n");
 
+       /* initialize FW descriptor as invalid */
+       fw_loader->dynamic_loader.fw_desc_valid = false;
+
        /*
         * In this stage, "cpu_dyn_regs" contains only LKD's hard coded values!
         * It will be updated from FW after hl_fw_dynamic_request_descriptor().
@@ -2325,7 +2337,8 @@ static int hl_fw_dynamic_init_cpu(struct hl_device *hdev,
        return 0;
 
 protocol_err:
-       fw_read_errors(hdev, le32_to_cpu(dyn_regs->cpu_boot_err0),
+       if (fw_loader->dynamic_loader.fw_desc_valid)
+               fw_read_errors(hdev, le32_to_cpu(dyn_regs->cpu_boot_err0),
                                le32_to_cpu(dyn_regs->cpu_boot_err1),
                                le32_to_cpu(dyn_regs->cpu_boot_dev_sts0),
                                le32_to_cpu(dyn_regs->cpu_boot_dev_sts1));

diff --git a/drivers/misc/habanalabs/common/habanalabs.h b/drivers/misc/habanalabs/common/habanalabs.h
index bebebcb..dfcd87b 100644 (file)
--- a/drivers/misc/habanalabs/common/habanalabs.h
+++ b/drivers/misc/habanalabs/common/habanalabs.h
@@ -992,6 +992,7 @@ struct fw_response {
  * @image_region: region to copy the FW image to
  * @fw_image_size: size of FW image to load
  * @wait_for_bl_timeout: timeout for waiting for boot loader to respond
+ * @fw_desc_valid: true if FW descriptor has been validated and hence the data can be used
  */
 struct dynamic_fw_load_mgr {
        struct fw_response response;
@@ -999,6 +1000,7 @@ struct dynamic_fw_load_mgr {
        struct pci_mem_region *image_region;
        size_t fw_image_size;
        u32 wait_for_bl_timeout;
+       bool fw_desc_valid;
 };
 
 /**