2 files changed, 53 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-cxl b/Documentation/ABI/testing/sysfs-class-cxl
index 2ab97527e186..5941ff38d4a3 100644
--- a/Documentation/ABI/testing/sysfs-class-cxl
+++ b/Documentation/ABI/testing/sysfs-class-cxl
@@ -132,3 +132,17 @@ Contact:        linuxppc-dev@lists.ozlabs.org
 Description:    read only
                 Will return "user" or "factory" depending on the image loaded
                 onto the card.
+
+What:           /sys/class/cxl/<card>/load_image_on_perst
+Date:           December 2014
+Contact:        linuxppc-dev@lists.ozlabs.org
+Description:    read/write
+                Valid entries are "none", "user", and "factory".
+                "none" means PERST will not cause image to be loaded to the
+                card.  A power cycle is required to load the image.
+                "none" could be useful for debugging because the trace arrays
+                are preserved.
+                "user" and "factory" means PERST will cause either the user or
+                user or factory image to be loaded.
+                Default is to reload on PERST whichever image the card has
+                loaded.
diff --git a/drivers/misc/cxl/sysfs.c b/drivers/misc/cxl/sysfs.c
index 461bdbd5d483..ed4ad461143c 100644
--- a/drivers/misc/cxl/sysfs.c
+++ b/drivers/misc/cxl/sysfs.c
@@ -56,11 +56,50 @@ static ssize_t image_loaded_show(struct device *device,
         return scnprintf(buf, PAGE_SIZE, "factory\n");
 }
 
+static ssize_t load_image_on_perst_show(struct device *device,
+                                 struct device_attribute *attr,
+                                 char *buf)
+{
+        struct cxl *adapter = to_cxl_adapter(device);
+
+        if (!adapter->perst_loads_image)
+                return scnprintf(buf, PAGE_SIZE, "none\n");
+
+        if (adapter->perst_select_user)
+                return scnprintf(buf, PAGE_SIZE, "user\n");
+        return scnprintf(buf, PAGE_SIZE, "factory\n");
+}
+
+static ssize_t load_image_on_perst_store(struct device *device,
+                                 struct device_attribute *attr,
+                                 const char *buf, size_t count)
+{
+        struct cxl *adapter = to_cxl_adapter(device);
+        int rc;
+
+        if (!strncmp(buf, "none", 4))
+                adapter->perst_loads_image = false;
+        else if (!strncmp(buf, "user", 4)) {
+                adapter->perst_select_user = true;
+                adapter->perst_loads_image = true;
+        } else if (!strncmp(buf, "factory", 7)) {
+                adapter->perst_select_user = false;
+                adapter->perst_loads_image = true;
+        } else
+                return -EINVAL;
+
+        if ((rc = cxl_update_image_control(adapter)))
+                return rc;
+
+        return count;
+}
+
 static struct device_attribute adapter_attrs[] = {
         __ATTR_RO(caia_version),
         __ATTR_RO(psl_revision),
         __ATTR_RO(base_image),
         __ATTR_RO(image_loaded),
+        __ATTR_RW(load_image_on_perst),
 };