[PATCH v4 2/4] firmware: encapsulate firmware loading status

From: Daniel Wagner
Date: Wed Sep 07 2016 - 04:45:52 EST


From: Daniel Wagner <daniel.wagner@xxxxxxxxxxxx>

The firmware user helper code tracks the current state of the loading
process via unsigned long status and a complection in struct
firmware_buf. We only need this for the usermode helper as such we can
encapsulate all this data into its own data structure.

Signed-off-by: Daniel Wagner <daniel.wagner@xxxxxxxxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxxxxx>
Cc: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/base/firmware_class.c | 123 ++++++++++++++++++++++++++++++------------
1 file changed, 88 insertions(+), 35 deletions(-)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index d4fee06..b11fbb0 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -91,10 +91,13 @@ static inline bool fw_is_builtin_firmware(const struct firmware *fw)
}
#endif

+#ifdef CONFIG_FW_LOADER_USER_HELPER
+
enum {
+ FW_STATUS_UNKNOWN,
FW_STATUS_LOADING,
FW_STATUS_DONE,
- FW_STATUS_ABORT,
+ FW_STATUS_ABORTED,
};

static int loading_timeout = 60; /* In seconds */
@@ -104,6 +107,69 @@ static inline long firmware_loading_timeout(void)
return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
}

+struct fw_status {
+ unsigned long status;
+ struct completion completion;
+};
+
+static void fw_status_init(struct fw_status *fw_st)
+{
+ fw_st->status = FW_STATUS_UNKNOWN;
+ init_completion(&fw_st->completion);
+}
+
+static int __fw_status_check(struct fw_status *fw_st, unsigned long status)
+{
+ return test_bit(status, &fw_st->status);
+}
+
+static int fw_status_wait_timeout(struct fw_status *fw_st, long timeout)
+{
+ int ret;
+
+ ret = wait_for_completion_interruptible_timeout(&fw_st->completion,
+ timeout);
+ if (ret == 0 && test_bit(FW_STATUS_ABORTED, &fw_st->status))
+ return -ENOENT;
+
+ return ret;
+}
+
+static void __fw_status_set(struct fw_status *fw_st,
+ unsigned long status)
+{
+ set_bit(status, &fw_st->status);
+
+ if (status == FW_STATUS_DONE ||
+ status == FW_STATUS_ABORTED) {
+ clear_bit(FW_STATUS_LOADING, &fw_st->status);
+ complete_all(&fw_st->completion);
+ }
+}
+
+#define fw_status_start(fw_st) \
+ __fw_status_set(fw_st, FW_STATUS_LOADING)
+#define fw_status_done(fw_st) \
+ __fw_status_set(fw_st, FW_STATUS_DONE)
+#define fw_status_aborted(fw_st) \
+ __fw_status_set(fw_st, FW_STATUS_ABORTED)
+#define fw_status_is_loading(fw_st) \
+ __fw_status_check(fw_st, FW_STATUS_LOADING)
+#define fw_status_is_done(fw_st) \
+ __fw_status_check(fw_st, FW_STATUS_DONE)
+#define fw_status_is_aborted(fw_st) \
+ __fw_status_check(fw_st, FW_STATUS_ABORTED)
+
+#else /* CONFIG_FW_LOADER_USER_HELPER */
+
+#define fw_status_wait_timeout(fw_st, long) 0
+
+#define fw_status_done(fw_st)
+#define fw_status_is_done(fw_st) true
+#define fw_status_is_aborted(fw_st) false
+
+#endif /* !CONFIG_FW_LOADER_USER_HELPER */
+
/* firmware behavior options */
#define FW_OPT_UEVENT (1U << 0)
#define FW_OPT_NOWAIT (1U << 1)
@@ -145,13 +211,12 @@ struct firmware_cache {
struct firmware_buf {
struct kref ref;
struct list_head list;
- struct completion completion;
struct firmware_cache *fwc;
- unsigned long status;
void *data;
size_t size;
size_t allocated_size;
#ifdef CONFIG_FW_LOADER_USER_HELPER
+ struct fw_status fw_st;
bool is_paged_buf;
bool need_uevent;
struct page **pages;
@@ -205,8 +270,8 @@ static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
buf->fwc = fwc;
buf->data = dbuf;
buf->allocated_size = size;
- init_completion(&buf->completion);
#ifdef CONFIG_FW_LOADER_USER_HELPER
+ fw_status_init(&buf->fw_st);
INIT_LIST_HEAD(&buf->pending_list);
#endif

@@ -309,8 +374,7 @@ static void fw_finish_direct_load(struct device *device,
struct firmware_buf *buf)
{
mutex_lock(&fw_lock);
- set_bit(FW_STATUS_DONE, &buf->status);
- complete_all(&buf->completion);
+ fw_status_done(&buf->fw_st);
mutex_unlock(&fw_lock);
}

@@ -478,12 +542,11 @@ static void __fw_load_abort(struct firmware_buf *buf)
* There is a small window in which user can write to 'loading'
* between loading done and disappearance of 'loading'
*/
- if (test_bit(FW_STATUS_DONE, &buf->status))
+ if (fw_status_is_done(&buf->fw_st))
return;

list_del_init(&buf->pending_list);
- set_bit(FW_STATUS_ABORT, &buf->status);
- complete_all(&buf->completion);
+ fw_status_aborted(&buf->fw_st);
}

static void fw_load_abort(struct firmware_priv *fw_priv)
@@ -496,9 +559,6 @@ static void fw_load_abort(struct firmware_priv *fw_priv)
fw_priv->buf = NULL;
}

-#define is_fw_load_aborted(buf) \
- test_bit(FW_STATUS_ABORT, &(buf)->status)
-
static LIST_HEAD(pending_fw_head);

/* reboot notifier for avoid deadlock with usermode_lock */
@@ -598,7 +658,7 @@ static ssize_t firmware_loading_show(struct device *dev,

mutex_lock(&fw_lock);
if (fw_priv->buf)
- loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
+ loading = fw_status_is_loading(&fw_priv->buf->fw_st);
mutex_unlock(&fw_lock);

return sprintf(buf, "%d\n", loading);
@@ -653,23 +713,20 @@ static ssize_t firmware_loading_store(struct device *dev,
switch (loading) {
case 1:
/* discarding any previous partial load */
- if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) {
+ if (!fw_status_is_done(&fw_buf->fw_st)) {
for (i = 0; i < fw_buf->nr_pages; i++)
__free_page(fw_buf->pages[i]);
vfree(fw_buf->pages);
fw_buf->pages = NULL;
fw_buf->page_array_size = 0;
fw_buf->nr_pages = 0;
- set_bit(FW_STATUS_LOADING, &fw_buf->status);
+ fw_status_start(&fw_buf->fw_st);
}
break;
case 0:
- if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
+ if (fw_status_is_loading(&fw_buf->fw_st)) {
int rc;

- set_bit(FW_STATUS_DONE, &fw_buf->status);
- clear_bit(FW_STATUS_LOADING, &fw_buf->status);
-
/*
* Several loading requests may be pending on
* one same firmware buf, so let all requests
@@ -691,10 +748,11 @@ static ssize_t firmware_loading_store(struct device *dev,
*/
list_del_init(&fw_buf->pending_list);
if (rc) {
- set_bit(FW_STATUS_ABORT, &fw_buf->status);
+ fw_status_aborted(&fw_buf->fw_st);
written = rc;
+ } else {
+ fw_status_done(&fw_buf->fw_st);
}
- complete_all(&fw_buf->completion);
break;
}
/* fallthrough */
@@ -702,7 +760,7 @@ static ssize_t firmware_loading_store(struct device *dev,
dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
/* fallthrough */
case -1:
- fw_load_abort(fw_priv);
+ fw_status_aborted(&fw_buf->fw_st);
break;
}
out:
@@ -755,7 +813,7 @@ static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,

mutex_lock(&fw_lock);
buf = fw_priv->buf;
- if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
+ if (!buf || fw_status_is_done(&buf->fw_st)) {
ret_count = -ENODEV;
goto out;
}
@@ -842,7 +900,7 @@ static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,

mutex_lock(&fw_lock);
buf = fw_priv->buf;
- if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
+ if (!buf || fw_status_is_done(&buf->fw_st)) {
retval = -ENODEV;
goto out;
}
@@ -955,8 +1013,7 @@ static int _request_firmware_load(struct firmware_priv *fw_priv,
timeout = MAX_JIFFY_OFFSET;
}

- retval = wait_for_completion_interruptible_timeout(&buf->completion,
- timeout);
+ retval = fw_status_wait_timeout(&buf->fw_st, timeout);
if (retval == -ERESTARTSYS || !retval) {
mutex_lock(&fw_lock);
fw_load_abort(fw_priv);
@@ -965,7 +1022,7 @@ static int _request_firmware_load(struct firmware_priv *fw_priv,
retval = 0;
}

- if (is_fw_load_aborted(buf))
+ if (fw_status_is_aborted(&buf->fw_st))
retval = -EAGAIN;
else if (buf->is_paged_buf && !buf->data)
retval = -ENOMEM;
@@ -1040,29 +1097,25 @@ fw_load_from_user_helper(struct firmware *firmware, const char *name,
return -ENOENT;
}

-/* No abort during direct loading */
-#define is_fw_load_aborted(buf) false
-
#ifdef CONFIG_PM_SLEEP
static inline void kill_requests_without_uevent(void) { }
#endif

#endif /* CONFIG_FW_LOADER_USER_HELPER */

-
/* wait until the shared firmware_buf becomes ready (or error) */
static int sync_cached_firmware_buf(struct firmware_buf *buf)
{
int ret = 0;

mutex_lock(&fw_lock);
- while (!test_bit(FW_STATUS_DONE, &buf->status)) {
- if (is_fw_load_aborted(buf)) {
+ while (!fw_status_is_done(&buf->fw_st)) {
+ if (fw_status_is_aborted(&buf->fw_st)) {
ret = -ENOENT;
break;
}
mutex_unlock(&fw_lock);
- ret = wait_for_completion_interruptible(&buf->completion);
+ ret = fw_status_wait_timeout(&buf->fw_st, 0);
mutex_lock(&fw_lock);
}
mutex_unlock(&fw_lock);
@@ -1120,7 +1173,7 @@ static int assign_firmware_buf(struct firmware *fw, struct device *device,
struct firmware_buf *buf = fw->priv;

mutex_lock(&fw_lock);
- if (!buf->size || is_fw_load_aborted(buf)) {
+ if (!buf->size || fw_status_is_aborted(&buf->fw_st)) {
mutex_unlock(&fw_lock);
return -ENOENT;
}
--
2.7.4