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>
---
v2:
  - Bumped documentation date and version
  - Added warning to sec_progress() for invalid progress status
  - Added sec_error() function (similar to sec_progress())
---
 .../ABI/testing/sysfs-class-ifpga-sec-mgr     | 17 ++++
 drivers/fpga/ifpga-sec-mgr.c                  | 81 ++++++++++++++++---
 include/linux/fpga/ifpga-sec-mgr.h            |  1 +
 3 files changed, 89 insertions(+), 10 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr 
b/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
index 73a5246fea1b..1f9f2c215e0c 100644
--- a/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
+++ b/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
@@ -89,3 +89,20 @@ 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:          Oct 2020
+KernelVersion:  5.11
+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 ad918fb42dc2..456ea0b71e3d 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;
        }
 
@@ -274,22 +280,76 @@ static const char * const sec_mgr_prog_str[] = {
        "programming"           /* IFPGA_SEC_PROG_PROGRAMMING */
 };
 
-static ssize_t
-status_show(struct device *dev, struct device_attribute *attr, char *buf)
+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(struct device *dev, enum ifpga_sec_prog prog)
 {
-       struct ifpga_sec_mgr *imgr = to_sec_mgr(dev);
        const char *status = "unknown-status";
 
-       if (imgr->progress < IFPGA_SEC_PROG_MAX)
-               status = sec_mgr_prog_str[imgr->progress];
+       if (prog < IFPGA_SEC_PROG_MAX)
+               status = sec_mgr_prog_str[prog];
        else
                dev_warn(dev, "Invalid status during secure update: %d\n",
-                        imgr->progress);
+                        prog);
+
+       return status;
+}
+
+static const char *sec_error(struct device *dev, enum ifpga_sec_err err_code)
+{
+       const char *error = "unknown-error";
+
+       if (err_code < IFPGA_SEC_ERR_MAX)
+               error = sec_mgr_err_str[err_code];
+       else
+               dev_warn(dev, "Invalid error code during secure update: %d\n",
+                        err_code);
+
+       return error;
+}
+
+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", status);
+       return sprintf(buf, "%s\n", sec_progress(dev, 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);
+       int ret;
+
+       mutex_lock(&imgr->lock);
+
+       if (imgr->progress != IFPGA_SEC_PROG_IDLE)
+               ret = -EBUSY;
+       else if (!imgr->err_code)
+               ret = 0;
+       else
+               ret = sprintf(buf, "%s:%s\n",
+                             sec_progress(dev, imgr->err_state),
+                             sec_error(dev, imgr->err_code));
+
+       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)
 {
@@ -325,6 +385,7 @@ 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 27008abd8e75..246e3d452c59 100644
--- a/include/linux/fpga/ifpga-sec-mgr.h
+++ b/include/linux/fpga/ifpga-sec-mgr.h
@@ -110,6 +110,7 @@ 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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