[PATCH v10 3/9] firmware: add request_partial_firmware_into_buf
Scott Branden
scott.branden at broadcom.com
Mon Jul 6 23:23:03 UTC 2020
Add request_partial_firmware_into_buf to allow for portions
of firmware file to be read into a buffer. Necessary where firmware
needs to be loaded in portions from file in memory constrained systems.
Signed-off-by: Scott Branden <scott.branden at broadcom.com>
---
drivers/base/firmware_loader/firmware.h | 5 ++
drivers/base/firmware_loader/main.c | 79 +++++++++++++++++++------
include/linux/firmware.h | 12 ++++
3 files changed, 79 insertions(+), 17 deletions(-)
diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h
index 933e2192fbe8..b5487f66dc45 100644
--- a/drivers/base/firmware_loader/firmware.h
+++ b/drivers/base/firmware_loader/firmware.h
@@ -32,6 +32,8 @@
* @FW_OPT_FALLBACK_PLATFORM: Enable fallback to device fw copy embedded in
* the platform's main firmware. If both this fallback and the sysfs
* fallback are enabled, then this fallback will be tried first.
+ * @FW_OPT_PARTIAL: Allow partial read of firmware instead of needing to read
+ * entire file.
*/
enum fw_opt {
FW_OPT_UEVENT = BIT(0),
@@ -41,6 +43,7 @@ enum fw_opt {
FW_OPT_NOCACHE = BIT(4),
FW_OPT_NOFALLBACK_SYSFS = BIT(5),
FW_OPT_FALLBACK_PLATFORM = BIT(6),
+ FW_OPT_PARTIAL = BIT(7),
};
enum fw_status {
@@ -68,6 +71,8 @@ struct fw_priv {
void *data;
size_t size;
size_t allocated_size;
+ size_t offset;
+ u32 opt_flags;
#ifdef CONFIG_FW_LOADER_PAGED_BUF
bool is_paged_buf;
struct page **pages;
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 7ca229760dfc..7a8d1877265c 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -168,7 +168,10 @@ static int fw_cache_piggyback_on_request(const char *name);
static struct fw_priv *__allocate_fw_priv(const char *fw_name,
struct firmware_cache *fwc,
- void *dbuf, size_t size)
+ void *dbuf,
+ size_t size,
+ size_t offset,
+ u32 opt_flags)
{
struct fw_priv *fw_priv;
@@ -186,6 +189,8 @@ static struct fw_priv *__allocate_fw_priv(const char *fw_name,
fw_priv->fwc = fwc;
fw_priv->data = dbuf;
fw_priv->allocated_size = size;
+ fw_priv->offset = offset;
+ fw_priv->opt_flags = opt_flags;
fw_state_init(fw_priv);
#ifdef CONFIG_FW_LOADER_USER_HELPER
INIT_LIST_HEAD(&fw_priv->pending_list);
@@ -210,8 +215,11 @@ static struct fw_priv *__lookup_fw_priv(const char *fw_name)
/* Returns 1 for batching firmware requests with the same name */
static int alloc_lookup_fw_priv(const char *fw_name,
struct firmware_cache *fwc,
- struct fw_priv **fw_priv, void *dbuf,
- size_t size, u32 opt_flags)
+ struct fw_priv **fw_priv,
+ void *dbuf,
+ size_t size,
+ size_t offset,
+ u32 opt_flags)
{
struct fw_priv *tmp;
@@ -227,7 +235,7 @@ static int alloc_lookup_fw_priv(const char *fw_name,
}
}
- tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size);
+ tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, offset, opt_flags);
if (tmp) {
INIT_LIST_HEAD(&tmp->list);
if (!(opt_flags & FW_OPT_NOCACHE))
@@ -473,7 +481,11 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
/* Already populated data member means we're loading into a buffer */
if (!decompress && fw_priv->data) {
buffer = fw_priv->data;
- id = READING_FIRMWARE_PREALLOC_BUFFER;
+ if (fw_priv->opt_flags & FW_OPT_PARTIAL)
+ id = READING_FIRMWARE_PARTIAL_READ;
+ else
+ id = READING_FIRMWARE_PREALLOC_BUFFER;
+
msize = fw_priv->allocated_size;
}
@@ -496,8 +508,10 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
fw_priv->size = 0;
/* load firmware files from the mount namespace of init */
- rc = kernel_read_file_from_path_initns(path, &buffer,
- &size, msize, id);
+ rc = kernel_pread_file_from_path_initns(path, &buffer,
+ &size, msize,
+ fw_priv->offset,
+ id);
if (rc) {
if (rc != -ENOENT)
dev_warn(device, "loading %s failed with error %d\n",
@@ -684,7 +698,7 @@ int assign_fw(struct firmware *fw, struct device *device, u32 opt_flags)
static int
_request_firmware_prepare(struct firmware **firmware_p, const char *name,
struct device *device, void *dbuf, size_t size,
- u32 opt_flags)
+ size_t offset, u32 opt_flags)
{
struct firmware *firmware;
struct fw_priv *fw_priv;
@@ -703,7 +717,7 @@ _request_firmware_prepare(struct firmware **firmware_p, const char *name,
}
ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size,
- opt_flags);
+ offset, opt_flags);
/*
* bind with 'priv' now to avoid warning in failure path
@@ -750,7 +764,7 @@ static void fw_abort_batch_reqs(struct firmware *fw)
static int
_request_firmware(const struct firmware **firmware_p, const char *name,
struct device *device, void *buf, size_t size,
- u32 opt_flags)
+ size_t offset, u32 opt_flags)
{
struct firmware *fw = NULL;
int ret;
@@ -764,7 +778,7 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
}
ret = _request_firmware_prepare(&fw, name, device, buf, size,
- opt_flags);
+ offset, opt_flags);
if (ret <= 0) /* error or already assigned */
goto out;
@@ -826,7 +840,7 @@ request_firmware(const struct firmware **firmware_p, const char *name,
/* Need to pin this module until return */
__module_get(THIS_MODULE);
- ret = _request_firmware(firmware_p, name, device, NULL, 0,
+ ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
FW_OPT_UEVENT);
module_put(THIS_MODULE);
return ret;
@@ -853,7 +867,7 @@ int firmware_request_nowarn(const struct firmware **firmware, const char *name,
/* Need to pin this module until return */
__module_get(THIS_MODULE);
- ret = _request_firmware(firmware, name, device, NULL, 0,
+ ret = _request_firmware(firmware, name, device, NULL, 0, 0,
FW_OPT_UEVENT | FW_OPT_NO_WARN);
module_put(THIS_MODULE);
return ret;
@@ -877,7 +891,7 @@ int request_firmware_direct(const struct firmware **firmware_p,
int ret;
__module_get(THIS_MODULE);
- ret = _request_firmware(firmware_p, name, device, NULL, 0,
+ ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
FW_OPT_UEVENT | FW_OPT_NO_WARN |
FW_OPT_NOFALLBACK_SYSFS);
module_put(THIS_MODULE);
@@ -902,7 +916,7 @@ int firmware_request_platform(const struct firmware **firmware,
/* Need to pin this module until return */
__module_get(THIS_MODULE);
- ret = _request_firmware(firmware, name, device, NULL, 0,
+ ret = _request_firmware(firmware, name, device, NULL, 0, 0,
FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
module_put(THIS_MODULE);
return ret;
@@ -958,13 +972,44 @@ request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
return -EOPNOTSUPP;
__module_get(THIS_MODULE);
- ret = _request_firmware(firmware_p, name, device, buf, size,
+ ret = _request_firmware(firmware_p, name, device, buf, size, 0,
FW_OPT_UEVENT | FW_OPT_NOCACHE);
module_put(THIS_MODULE);
return ret;
}
EXPORT_SYMBOL(request_firmware_into_buf);
+/**
+ * request_partial_firmware_into_buf() - load partial firmware into a previously allocated buffer
+ * @firmware_p: pointer to firmware image
+ * @name: name of firmware file
+ * @device: device for which firmware is being loaded and DMA region allocated
+ * @buf: address of buffer to load firmware into
+ * @size: size of buffer
+ * @offset: offset into file to read
+ *
+ * This function works pretty much like request_firmware_into_buf except
+ * it allows a partial read of the file.
+ */
+int
+request_partial_firmware_into_buf(const struct firmware **firmware_p,
+ const char *name, struct device *device,
+ void *buf, size_t size, size_t offset)
+{
+ int ret;
+
+ if (fw_cache_is_setup(device, name))
+ return -EOPNOTSUPP;
+
+ __module_get(THIS_MODULE);
+ ret = _request_firmware(firmware_p, name, device, buf, size, offset,
+ FW_OPT_UEVENT | FW_OPT_NOCACHE |
+ FW_OPT_PARTIAL);
+ module_put(THIS_MODULE);
+ return ret;
+}
+EXPORT_SYMBOL(request_partial_firmware_into_buf);
+
/**
* release_firmware() - release the resource associated with a firmware image
* @fw: firmware resource to release
@@ -997,7 +1042,7 @@ static void request_firmware_work_func(struct work_struct *work)
fw_work = container_of(work, struct firmware_work, work);
- _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0,
+ _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0, 0,
fw_work->opt_flags);
fw_work->cont(fw, fw_work->context);
put_device(fw_work->device); /* taken in request_firmware_nowait() */
diff --git a/include/linux/firmware.h b/include/linux/firmware.h
index cb3e2c06ed8a..c15acadc6cf4 100644
--- a/include/linux/firmware.h
+++ b/include/linux/firmware.h
@@ -53,6 +53,9 @@ int request_firmware_direct(const struct firmware **fw, const char *name,
struct device *device);
int request_firmware_into_buf(const struct firmware **firmware_p,
const char *name, struct device *device, void *buf, size_t size);
+int request_partial_firmware_into_buf(const struct firmware **firmware_p,
+ const char *name, struct device *device,
+ void *buf, size_t size, size_t offset);
void release_firmware(const struct firmware *fw);
#else
@@ -102,6 +105,15 @@ static inline int request_firmware_into_buf(const struct firmware **firmware_p,
return -EINVAL;
}
+static inline int request_partial_firmware_into_buf
+ (const struct firmware **firmware_p,
+ const char *name,
+ struct device *device,
+ void *buf, size_t size, size_t offset)
+{
+ return -EINVAL;
+}
+
#endif
int firmware_request_cache(struct device *device, const char *name);
--
2.17.1
More information about the Linux-security-module-archive
mailing list