Extend the Intel Security Manager class driver to include an optional update/hw_errinfo sysfs node that can be used to retrieve 64 bits of device specific error information following a secure update failure.
The underlying driver must provide a get_hw_errinfo() callback function to enable this feature. This data is treated as opaque by the class driver. It is left to user-space software or support personnel to interpret this data. Signed-off-by: Russ Weight <[email protected]> Reviewed-by: Tom Rix <[email protected]> --- v2: - Bumped documentation date and version --- .../ABI/testing/sysfs-class-ifpga-sec-mgr | 14 +++++++ drivers/fpga/ifpga-sec-mgr.c | 38 +++++++++++++++++++ include/linux/fpga/ifpga-sec-mgr.h | 5 +++ 3 files changed, 57 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr b/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr index caafe7eb7670..37a335ff4936 100644 --- a/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr +++ b/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr @@ -127,3 +127,17 @@ Description: Read-only. Returns a string describing the failure idle state. If this file is read while a secure update is in progress, then the read will fail with EBUSY. + +What: /sys/class/ifpga_sec_mgr/ifpga_secX/update/hw_errinfo +Date: Oct 2020 +KernelVersion: 5.11 +Contact: Russ Weight <[email protected]> +Description: Read-only. Returns a 64 bit error value providing + hardware specific information that may be useful in + debugging errors that occur during FPGA image updates. + This file is only visible if the underlying device + supports it. The hw_errinfo value is only accessible + when the secure update engine is in the idle state. + If this file is read while a secure update is in + progress, then the read will fail with EBUSY. + Format: "0x%llx". diff --git a/drivers/fpga/ifpga-sec-mgr.c b/drivers/fpga/ifpga-sec-mgr.c index 6267ac3a0780..eb306dff7d31 100644 --- a/drivers/fpga/ifpga-sec-mgr.c +++ b/drivers/fpga/ifpga-sec-mgr.c @@ -152,10 +152,17 @@ static void set_error(struct ifpga_sec_mgr *imgr, enum ifpga_sec_err err_code) imgr->err_code = err_code; } +static void set_hw_errinfo(struct ifpga_sec_mgr *imgr) +{ + if (imgr->iops->get_hw_errinfo) + imgr->hw_errinfo = imgr->iops->get_hw_errinfo(imgr); +} + static void ifpga_sec_dev_error(struct ifpga_sec_mgr *imgr, enum ifpga_sec_err err_code) { set_error(imgr, err_code); + set_hw_errinfo(imgr); imgr->iops->cancel(imgr); } @@ -373,6 +380,23 @@ error_show(struct device *dev, struct device_attribute *attr, char *buf) } static DEVICE_ATTR_RO(error); +static ssize_t +hw_errinfo_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct ifpga_sec_mgr *imgr = to_sec_mgr(dev); + int ret; + + mutex_lock(&imgr->lock); + if (imgr->progress != IFPGA_SEC_PROG_IDLE) + ret = -EBUSY; + else + ret = sprintf(buf, "0x%llx\n", imgr->hw_errinfo); + mutex_unlock(&imgr->lock); + + return ret; +} +static DEVICE_ATTR_RO(hw_errinfo); + static ssize_t remaining_size_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -404,6 +428,7 @@ static ssize_t filename_store(struct device *dev, struct device_attribute *attr, } imgr->err_code = IFPGA_SEC_ERR_NONE; + imgr->hw_errinfo = 0; imgr->request_cancel = false; imgr->progress = IFPGA_SEC_PROG_READING; reinit_completion(&imgr->update_done); @@ -438,18 +463,31 @@ static ssize_t cancel_store(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_WO(cancel); +static umode_t +sec_mgr_update_visible(struct kobject *kobj, struct attribute *attr, int n) +{ + struct ifpga_sec_mgr *imgr = to_sec_mgr(kobj_to_dev(kobj)); + + if (attr == &dev_attr_hw_errinfo.attr && !imgr->iops->get_hw_errinfo) + return 0; + + return attr->mode; +} + static struct attribute *sec_mgr_update_attrs[] = { &dev_attr_filename.attr, &dev_attr_cancel.attr, &dev_attr_status.attr, &dev_attr_error.attr, &dev_attr_remaining_size.attr, + &dev_attr_hw_errinfo.attr, NULL, }; static struct attribute_group sec_mgr_update_attr_group = { .name = "update", .attrs = sec_mgr_update_attrs, + .is_visible = sec_mgr_update_visible, }; static ssize_t name_show(struct device *dev, diff --git a/include/linux/fpga/ifpga-sec-mgr.h b/include/linux/fpga/ifpga-sec-mgr.h index 890be0800b05..baf4fe876164 100644 --- a/include/linux/fpga/ifpga-sec-mgr.h +++ b/include/linux/fpga/ifpga-sec-mgr.h @@ -60,6 +60,9 @@ enum ifpga_sec_err { * function and is called at the completion * of the update, whether success or failure, * if the prepare function succeeded. + * @get_hw_errinfo: Optional: Return u64 hw specific error info. + * The software err_code may used to determine + * whether the hw error info is applicable. */ struct ifpga_sec_mgr_ops { int (*user_flash_count)(struct ifpga_sec_mgr *imgr); @@ -87,6 +90,7 @@ struct ifpga_sec_mgr_ops { enum ifpga_sec_err (*poll_complete)(struct ifpga_sec_mgr *imgr); void (*cleanup)(struct ifpga_sec_mgr *imgr); enum ifpga_sec_err (*cancel)(struct ifpga_sec_mgr *imgr); + u64 (*get_hw_errinfo)(struct ifpga_sec_mgr *imgr); }; /* Update progress codes */ @@ -112,6 +116,7 @@ struct ifpga_sec_mgr { enum ifpga_sec_prog progress; enum ifpga_sec_prog err_state; /* progress state at time of failure */ enum ifpga_sec_err err_code; /* security manager error code */ + u64 hw_errinfo; /* 64 bits of HW specific error info */ bool request_cancel; bool driver_unload; void *priv; -- 2.17.1
