This patches introduce two kernel APIs of cache_firmware and
uncache_firmware, both of which take the firmware file name
as the only parameter.
So any drivers can call cache_firmware to cache the specified
firmware file into kernel memory, and can use the cached firmware
in situations which can't request firmware from user space.
Signed-off-by: Ming Lei <ming....@canonical.com>
---
drivers/base/firmware_class.c | 100 +++++++++++++++++++++++++++++++++++++----
include/linux/firmware.h | 12 +++++
2 files changed, 104 insertions(+), 8 deletions(-)
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 848ad97..fc119ce 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -142,6 +142,17 @@ static struct firmware_buf *__allocate_fw_buf(const char
*fw_name,
return buf;
}
+static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
+{
+ struct firmware_buf *tmp;
+ struct firmware_cache *fwc = &fw_cache;
+
+ list_for_each_entry(tmp, &fwc->head, list)
+ if (!strcmp(tmp->fw_id, fw_name))
+ return tmp;
+ return NULL;
+}
+
static int fw_lookup_and_allocate_buf(const char *fw_name,
struct firmware_cache *fwc,
struct firmware_buf **buf)
@@ -149,14 +160,13 @@ static int fw_lookup_and_allocate_buf(const char *fw_name,
struct firmware_buf *tmp;
spin_lock(&fwc->lock);
- list_for_each_entry(tmp, &fwc->head, list)
- if (!strcmp(tmp->fw_id, fw_name)) {
- kref_get(&tmp->ref);
- spin_unlock(&fwc->lock);
- *buf = tmp;
- return 1;
- }
-
+ tmp = __fw_lookup_buf(fw_name);
+ if (tmp) {
+ kref_get(&tmp->ref);
+ spin_unlock(&fwc->lock);
+ *buf = tmp;
+ return 1;
+ }
tmp = __allocate_fw_buf(fw_name, fwc);
if (tmp)
list_add(&tmp->list, &fwc->head);
@@ -167,6 +177,18 @@ static int fw_lookup_and_allocate_buf(const char *fw_name,
return tmp ? 0 : -ENOMEM;
}
+static struct firmware_buf *fw_lookup_buf(const char *fw_name)
+{
+ struct firmware_buf *tmp;
+ struct firmware_cache *fwc = &fw_cache;
+
+ spin_lock(&fwc->lock);
+ tmp = __fw_lookup_buf(fw_name);
+ spin_unlock(&fwc->lock);
+
+ return tmp;
+}
+
static void __fw_free_buf(struct kref *ref)
{
struct firmware_buf *buf = to_fwbuf(ref);
@@ -852,6 +874,66 @@ request_firmware_nowait(
return 0;
}
+/**
+ * cache_firmware - cache one firmware image in kernel memory space
+ * @fw_name: the firmware image name
+ *
+ * Cache firmware in kernel memory so that drivers can use it when
+ * system isn't ready for them to request firmware image from userspace.
+ * Once it returns successfully, driver can use request_firmware or its
+ * nowait version to get the cached firmware without any interacting
+ * with userspace
+ *
+ * Return 0 if the firmware image has been cached successfully
+ * Return !0 otherwise
+ *
+ */
+int cache_firmware(const char *fw_name)
+{
+ int ret;
+ const struct firmware *fw;
+
+ pr_debug("%s: %s\n", __func__, fw_name);
+
+ ret = request_firmware(&fw, fw_name, NULL);
+ if (!ret)
+ kfree(fw);
+
+ pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
+
+ return ret;
+}
+
+/**
+ * uncache_firmware - remove one cached firmware image
+ * @fw_name: the firmware image name
+ *
+ * Uncache one firmware image which has been cached successfully
+ * before.
+ *
+ * Return 0 if the firmware cache has been removed successfully
+ * Return !0 otherwise
+ *
+ */
+int uncache_firmware(const char *fw_name)
+{
+ struct firmware_buf *buf;
+ struct firmware fw;
+
+ pr_debug("%s: %s\n", __func__, fw_name);
+
+ if (fw_get_builtin_firmware(&fw, fw_name))
+ return 0;
+
+ buf = fw_lookup_buf(fw_name);
+ if (buf) {
+ fw_free_buf(buf);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
static int __init firmware_class_init(void)
{
fw_cache_init();
@@ -869,3 +951,5 @@ module_exit(firmware_class_exit);
EXPORT_SYMBOL(release_firmware);
EXPORT_SYMBOL(request_firmware);
EXPORT_SYMBOL(request_firmware_nowait);
+EXPORT_SYMBOL_GPL(cache_firmware);
+EXPORT_SYMBOL_GPL(uncache_firmware);
diff --git a/include/linux/firmware.h b/include/linux/firmware.h
index e85b771..e4279fe 100644
--- a/include/linux/firmware.h
+++ b/include/linux/firmware.h
@@ -47,6 +47,8 @@ int request_firmware_nowait(
void (*cont)(const struct firmware *fw, void *context));
void release_firmware(const struct firmware *fw);
+int cache_firmware(const char *name);
+int uncache_firmware(const char *name);
#else
static inline int request_firmware(const struct firmware **fw,
const char *name,
@@ -65,6 +67,16 @@ static inline int request_firmware_nowait(
static inline void release_firmware(const struct firmware *fw)
{
}
+
+static inline int cache_firmware(const char *name)
+{
+ return -ENOENT;
+}
+
+static inline int uncache_firmware(const char *name)
+{
+ return -EINVAL;
+}
#endif
#endif
--
1.7.9.5
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