On Mon, May 03, 2021 at 02:35:43PM -0700, Russ Weight wrote:
> Extend the FPGA 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@xxxxxxxxx>
> Reviewed-by: Tom Rix <trix@xxxxxxxxxx>
> ---
> v12:
> - Updated Date and KernelVersion fields in ABI documentation
> - Changed syntax of sec_mgr_err_str[] array definition from:
> "none", /* FPGA_SEC_ERR_NONE */
> to:
> [FPGA_SEC_ERR_NONE] = "none",
> v11:
> - No change
> 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 error_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 dev_err() for invalid error code in sec_error()
> 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-fpga-sec-mgr | 17 ++++
> drivers/fpga/fpga-sec-mgr.c | 83 ++++++++++++++++---
> include/linux/fpga/fpga-sec-mgr.h | 1 +
> 3 files changed, 89 insertions(+), 12 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr b/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
> index b962ad2cf18d..24890d04521f 100644
> --- a/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
> +++ b/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
> @@ -27,3 +27,20 @@ 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/fpga_sec_mgr/fpga_secX/update/error
> +Date: June 2021
> +KernelVersion: 5.14
> +Contact: Russ Weight <russell.h.weight@xxxxxxxxx>
> +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/fpga-sec-mgr.c b/drivers/fpga/fpga-sec-mgr.c
> index dec52c68fe16..e43fa2797d27 100644
> --- a/drivers/fpga/fpga-sec-mgr.c
> +++ b/drivers/fpga/fpga-sec-mgr.c
> @@ -30,10 +30,16 @@ static void update_progress(struct fpga_sec_mgr *smgr,
> sysfs_notify(&smgr->dev.kobj, "update", "status");
> }
>
> +static void set_error(struct fpga_sec_mgr *smgr, enum fpga_sec_err err_code)
> +{
> + smgr->err_state = smgr->progress;
> + smgr->err_code = err_code;
> +}
Nit: Could this be fpga_sec_set_error() ?
> +
> static void fpga_sec_dev_error(struct fpga_sec_mgr *smgr,
> enum fpga_sec_err err_code)
> {
> - smgr->err_code = err_code;
> + set_error(smgr, err_code);
> smgr->sops->cancel(smgr);
> }
>
> @@ -56,7 +62,7 @@ static void fpga_sec_mgr_update(struct work_struct *work)
>
> get_device(&smgr->dev);
> if (request_firmware(&fw, smgr->filename, &smgr->dev)) {
> - smgr->err_code = FPGA_SEC_ERR_FILE_READ;
> + set_error(smgr, FPGA_SEC_ERR_FILE_READ);
> goto idle_exit;
> }
>
> @@ -64,7 +70,7 @@ static void fpga_sec_mgr_update(struct work_struct *work)
> smgr->remaining_size = fw->size;
>
> if (!try_module_get(smgr->dev.parent->driver->owner)) {
> - smgr->err_code = FPGA_SEC_ERR_BUSY;
> + set_error(smgr, FPGA_SEC_ERR_BUSY);
> goto release_fw_exit;
> }
>
> @@ -122,24 +128,76 @@ static const char * const sec_mgr_prog_str[] = {
> [FPGA_SEC_PROG_PROGRAMMING] = "programming"
> };
>
> -static ssize_t
> -status_show(struct device *dev, struct device_attribute *attr, char *buf)
> +static const char * const sec_mgr_err_str[] = {
> + [FPGA_SEC_ERR_NONE] = "none",
> + [FPGA_SEC_ERR_HW_ERROR] = "hw-error",
> + [FPGA_SEC_ERR_TIMEOUT] = "timeout",
> + [FPGA_SEC_ERR_CANCELED] = "user-abort",
> + [FPGA_SEC_ERR_BUSY] = "device-busy",
> + [FPGA_SEC_ERR_INVALID_SIZE] = "invalid-file-size",
> + [FPGA_SEC_ERR_RW_ERROR] = "read-write-error",
> + [FPGA_SEC_ERR_WEAROUT] = "flash-wearout",
> + [FPGA_SEC_ERR_FILE_READ] = "file-read-error"
> +};
> +
> +static const char *sec_progress(struct device *dev, enum fpga_sec_prog prog)
> {
> - 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];
> + if (prog < FPGA_SEC_PROG_MAX)
> + status = sec_mgr_prog_str[prog];
> else
> dev_err(dev, "Invalid status during secure update: %d\n",
> - progress);
> + prog);
> +
> + return status;
> +}
> +
> +static const char *sec_error(struct device *dev, enum fpga_sec_err err_code)
> +{
> + const char *error = "unknown-error";
> +
> + if (err_code < FPGA_SEC_ERR_MAX)
> + error = sec_mgr_err_str[err_code];
> + else
> + dev_err(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 fpga_sec_mgr *smgr = to_sec_mgr(dev);
>
> - return sysfs_emit(buf, "%s\n", status);
> + return sysfs_emit(buf, "%s\n", sec_progress(dev, smgr->progress));
> }
> static DEVICE_ATTR_RO(status);
>
> +static ssize_t
> +error_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct fpga_sec_mgr *smgr = to_sec_mgr(dev);
> + int ret;
> +
> + mutex_lock(&smgr->lock);
> +
> + if (smgr->progress != FPGA_SEC_PROG_IDLE)
> + ret = -EBUSY;
> + else if (!smgr->err_code)
> + ret = 0;
> + else
> + ret = sysfs_emit(buf, "%s:%s\n",
> + sec_progress(dev, smgr->err_state),
> + sec_error(dev, smgr->err_code));
> +
> + mutex_unlock(&smgr->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)
> {
> @@ -175,6 +233,7 @@ 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/fpga-sec-mgr.h b/include/linux/fpga/fpga-sec-mgr.h
> index 978ab98ffac5..6b7b8a3d6aac 100644
> --- a/include/linux/fpga/fpga-sec-mgr.h
> +++ b/include/linux/fpga/fpga-sec-mgr.h
> @@ -70,6 +70,7 @@ struct fpga_sec_mgr {
> const u8 *data; /* pointer to update data */
> u32 remaining_size; /* size remaining to transfer */
> enum fpga_sec_prog progress;
> + enum fpga_sec_prog err_state; /* progress state at time of failure */
> enum fpga_sec_err err_code; /* security manager error code */
> bool driver_unload;
> void *priv;
> --
> 2.25.1
>
Looks good,
Moritz
