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.wei...@intel.com>
Reviewed-by: Wu Hao <hao...@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.wei...@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

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