[PATCH v1 08/12] fpga: expose sec-mgr update errors

Russ Weight
2020-09-04T23:53:37Z

Extend Intel Security Manager class driver to include
an update/error sysfs node that can be read for error
information when a secure update fails.

Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Wu Hao <hao.wu@intel.com>
---
.../ABI/testing/sysfs-class-ifpga-sec-mgr | 17 ++++++
drivers/fpga/ifpga-sec-mgr.c | 60 +++++++++++++++++--
include/linux/fpga/ifpga-sec-mgr.h | 1 +
3 files changed, 73 insertions(+), 5 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr b/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
index 849ccb2802f8..e7b1b02bf7ee 100644
--- a/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
+++ b/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
@@ -97,3 +97,20 @@ Description: Read-only. Returns a string describing the current
programming. Userspace code can poll on this file,
as it will be signaled by sysfs_notify() on each
state change.
+
+What: /sys/class/ifpga_sec_mgr/ifpga_secX/update/error
+Date: Sep 2020
+KernelVersion: 5.10
+Contact: Russ Weight <russell.h.weight@intel.com>
+Description: Read-only. Returns a string describing the failure
+ of a secure update. This string will be in the form
+ of <STATUS>:<ERROR>, where <STATUS> will be one of
+ the status strings described for the status sysfs
+ file and <ERROR> will be one of the following:
+ hw-error, timeout, user-abort, device-busy,
+ invalid-file-size, read-write-error, flash-wearout,
+ file-read-error. The error sysfs file is only
+ meaningful 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.
diff --git a/drivers/fpga/ifpga-sec-mgr.c b/drivers/fpga/ifpga-sec-mgr.c
index 5fe3d85e2963..a7718bd8ee61 100644
--- a/drivers/fpga/ifpga-sec-mgr.c
+++ b/drivers/fpga/ifpga-sec-mgr.c
@@ -146,10 +146,16 @@ static void update_progress(struct ifpga_sec_mgr *imgr,
sysfs_notify(&imgr->dev.kobj, "update", "status");
}

+static void set_error(struct ifpga_sec_mgr *imgr, enum ifpga_sec_err err_code)
+{
+ imgr->err_state = imgr->progress;
+ imgr->err_code = err_code;
+}
+
static void ifpga_sec_dev_error(struct ifpga_sec_mgr *imgr,
enum ifpga_sec_err err_code)
{
- imgr->err_code = err_code;
+ set_error(imgr, err_code);
imgr->iops->cancel(imgr);
}

@@ -172,7 +178,7 @@ static void ifpga_sec_mgr_update(struct work_struct *work)

get_device(&imgr->dev);
if (request_firmware(&fw, imgr->filename, &imgr->dev)) {
- imgr->err_code = IFPGA_SEC_ERR_FILE_READ;
+ set_error(imgr, IFPGA_SEC_ERR_FILE_READ);
goto idle_exit;
}

@@ -180,7 +186,7 @@ static void ifpga_sec_mgr_update(struct work_struct *work)
imgr->remaining_size = fw->size;

if (!try_module_get(imgr->dev.parent->driver->owner)) {
- imgr->err_code = IFPGA_SEC_ERR_BUSY;
+ set_error(imgr, IFPGA_SEC_ERR_BUSY);
goto release_fw_exit;
}

@@ -266,16 +272,59 @@ static const char * const sec_mgr_prog_str[] = {
"programming" /* IFPGA_SEC_PROG_PROGRAMMING */
};

+static const char * const sec_mgr_err_str[] = {
+ "none", /* IFPGA_SEC_ERR_NONE */
+ "hw-error", /* IFPGA_SEC_ERR_HW_ERROR */
+ "timeout", /* IFPGA_SEC_ERR_TIMEOUT */
+ "user-abort", /* IFPGA_SEC_ERR_CANCELED */
+ "device-busy", /* IFPGA_SEC_ERR_BUSY */
+ "invalid-file-size", /* IFPGA_SEC_ERR_INVALID_SIZE */
+ "read-write-error", /* IFPGA_SEC_ERR_RW_ERROR */
+ "flash-wearout", /* IFPGA_SEC_ERR_WEAROUT */
+ "file-read-error" /* IFPGA_SEC_ERR_FILE_READ */
+};
+
+static const char *sec_progress(enum ifpga_sec_prog prog)
+{
+ return (prog < IFPGA_SEC_PROG_MAX) ?
+ sec_mgr_prog_str[prog] : "unknown-status";
+}
+
static ssize_t
status_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct ifpga_sec_mgr *imgr = to_sec_mgr(dev);

- return sprintf(buf, "%s\n", (imgr->progress < IFPGA_SEC_PROG_MAX) ?
- sec_mgr_prog_str[imgr->progress] : "unknown-status");
+ return sprintf(buf, "%s\n", sec_progress(imgr->progress));
}
static DEVICE_ATTR_RO(status);

+static ssize_t
+error_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct ifpga_sec_mgr *imgr = to_sec_mgr(dev);
+ enum ifpga_sec_err err_code;
+ const char *prog_str;
+ int ret;
+
+ mutex_lock(&imgr->lock);
+ if (imgr->progress != IFPGA_SEC_PROG_IDLE) {
+ ret = -EBUSY;
+ } else if (!imgr->err_code) {
+ ret = 0;
+ } else {
+ err_code = imgr->err_code;
+ prog_str = sec_progress(imgr->err_state);
+ ret = sprintf(buf, "%s:%s\n", prog_str,
+ (err_code < IFPGA_SEC_ERR_MAX) ?
+ sec_mgr_err_str[err_code] : "unknown-error");
+ }
+ mutex_unlock(&imgr->lock);
+
+ return ret;
+}
+static DEVICE_ATTR_RO(error);
+
static ssize_t filename_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
@@ -314,6 +363,7 @@ static DEVICE_ATTR_WO(filename);
static struct attribute *sec_mgr_update_attrs[] = {
&dev_attr_filename.attr,
&dev_attr_status.attr,
+ &dev_attr_error.attr,
NULL,
};

diff --git a/include/linux/fpga/ifpga-sec-mgr.h b/include/linux/fpga/ifpga-sec-mgr.h
index 4da2864e251c..f04bf9e30c67 100644
--- a/include/linux/fpga/ifpga-sec-mgr.h
+++ b/include/linux/fpga/ifpga-sec-mgr.h
@@ -181,6 +181,7 @@ struct ifpga_sec_mgr {
const u8 *data; /* pointer to update data */
u32 remaining_size; /* size remaining to transfer */
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 */
bool driver_unload;
void *priv;
--
2.17.1