Extend the FPGA Security Manager class driver to
include an update/status sysfs node that can be polled
and read to monitor the progress of an ongoing secure
update. Sysfs_notify() is used to signal transitions
between different phases of the update process.

Signed-off-by: Russ Weight <russell.h.wei...@intel.com>
Reviewed-by: Tom Rix <t...@redhat.com>
---
v10:
  - Rebased to 5.12-rc2 next
  - Updated Date and KernelVersion in ABI documentation
v9:
  - Updated Date and KernelVersion in ABI documentation
v8:
  - No change
v7:
  - Changed Date in documentation file to December 2020
v6:
  - No change
v5:
  - Use new function sysfs_emit() in the status_show() function
v4:
  - Changed from "Intel FPGA Security Manager" to FPGA Security Manager"
    and removed unnecessary references to "Intel".
  - Changed: iops -> sops, imgr -> smgr, IFPGA_ -> FPGA_, ifpga_ to fpga_
v3:
  - Use a local variable to read progress once in status_show()
  - Use dev_err to report invalid progress status
v2:
  - Bumped documentation date and version
  - Changed progress state "read_file" to "reading"
---
 .../ABI/testing/sysfs-class-fpga-sec-mgr      | 11 +++++
 drivers/fpga/fpga-sec-mgr.c                   | 42 +++++++++++++++++--
 2 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr 
b/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
index 4c0bdfd25553..64420c101626 100644
--- a/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
+++ b/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
@@ -16,3 +16,14 @@ Description: Write only. Write the filename of an image
                BMC images, BMC firmware, Static Region images,
                and Root Entry Hashes, and to cancel Code Signing
                Keys (CSK).
+
+What:          /sys/class/fpga_sec_mgr/fpga_secX/update/status
+Date:          April 2021
+KernelVersion:  5.13
+Contact:       Russ Weight <russell.h.wei...@intel.com>
+Description:   Read-only. Returns a string describing the current
+               status of an update. The string will be one of the
+               following: idle, reading, preparing, writing,
+               programming. Userspace code can poll on this file,
+               as it will be signaled by sysfs_notify() on each
+               state change.
diff --git a/drivers/fpga/fpga-sec-mgr.c b/drivers/fpga/fpga-sec-mgr.c
index 7347ba1ba73e..dd60014b7511 100644
--- a/drivers/fpga/fpga-sec-mgr.c
+++ b/drivers/fpga/fpga-sec-mgr.c
@@ -25,6 +25,13 @@ struct fpga_sec_mgr_devres {
 
 #define to_sec_mgr(d) container_of(d, struct fpga_sec_mgr, dev)
 
+static void update_progress(struct fpga_sec_mgr *smgr,
+                           enum fpga_sec_prog new_progress)
+{
+       smgr->progress = new_progress;
+       sysfs_notify(&smgr->dev.kobj, "update", "status");
+}
+
 static void fpga_sec_dev_error(struct fpga_sec_mgr *smgr,
                               enum fpga_sec_err err_code)
 {
@@ -35,7 +42,7 @@ static void fpga_sec_dev_error(struct fpga_sec_mgr *smgr,
 static void progress_complete(struct fpga_sec_mgr *smgr)
 {
        mutex_lock(&smgr->lock);
-       smgr->progress = FPGA_SEC_PROG_IDLE;
+       update_progress(smgr, FPGA_SEC_PROG_IDLE);
        complete_all(&smgr->update_done);
        mutex_unlock(&smgr->lock);
 }
@@ -63,14 +70,14 @@ static void fpga_sec_mgr_update(struct work_struct *work)
                goto release_fw_exit;
        }
 
-       smgr->progress = FPGA_SEC_PROG_PREPARING;
+       update_progress(smgr, FPGA_SEC_PROG_PREPARING);
        ret = smgr->sops->prepare(smgr);
        if (ret != FPGA_SEC_ERR_NONE) {
                fpga_sec_dev_error(smgr, ret);
                goto modput_exit;
        }
 
-       smgr->progress = FPGA_SEC_PROG_WRITING;
+       update_progress(smgr, FPGA_SEC_PROG_WRITING);
        size = smgr->remaining_size;
        while (size) {
                blk_size = min_t(u32, size, WRITE_BLOCK_SIZE);
@@ -85,7 +92,7 @@ static void fpga_sec_mgr_update(struct work_struct *work)
                offset += blk_size;
        }
 
-       smgr->progress = FPGA_SEC_PROG_PROGRAMMING;
+       update_progress(smgr, FPGA_SEC_PROG_PROGRAMMING);
        ret = smgr->sops->poll_complete(smgr);
        if (ret != FPGA_SEC_ERR_NONE)
                fpga_sec_dev_error(smgr, ret);
@@ -113,6 +120,32 @@ static void fpga_sec_mgr_update(struct work_struct *work)
        progress_complete(smgr);
 }
 
+static const char * const sec_mgr_prog_str[] = {
+       "idle",                 /* FPGA_SEC_PROG_IDLE */
+       "reading",              /* FPGA_SEC_PROG_READING */
+       "preparing",            /* FPGA_SEC_PROG_PREPARING */
+       "writing",              /* FPGA_SEC_PROG_WRITING */
+       "programming"           /* FPGA_SEC_PROG_PROGRAMMING */
+};
+
+static ssize_t
+status_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+       struct fpga_sec_mgr *smgr = to_sec_mgr(dev);
+       const char *status = "unknown-status";
+       enum fpga_sec_prog progress;
+
+       progress = smgr->progress;
+       if (progress < FPGA_SEC_PROG_MAX)
+               status = sec_mgr_prog_str[progress];
+       else
+               dev_err(dev, "Invalid status during secure update: %d\n",
+                       progress);
+
+       return sysfs_emit(buf, "%s\n", status);
+}
+static DEVICE_ATTR_RO(status);
+
 static ssize_t filename_store(struct device *dev, struct device_attribute 
*attr,
                              const char *buf, size_t count)
 {
@@ -147,6 +180,7 @@ static DEVICE_ATTR_WO(filename);
 
 static struct attribute *sec_mgr_update_attrs[] = {
        &dev_attr_filename.attr,
+       &dev_attr_status.attr,
        NULL,
 };
 
-- 
2.25.1

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