[PATCH v6 2/8] firmware: add offset to request_firmware_into_buf

Scott Branden
2020-06-05T23:00:22Z

Add offset to request_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@broadcom.com>
---
drivers/base/firmware_loader/firmware.h | 5 +++
drivers/base/firmware_loader/main.c | 53 +++++++++++++++++--------
drivers/soc/qcom/mdt_loader.c | 7 +++-
include/linux/firmware.h | 8 +++-
lib/test_firmware.c | 4 +-
5 files changed, 56 insertions(+), 21 deletions(-)

diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h
index 933e2192fbe8..c9b6ba8d29d8 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;
+ enum kernel_pread_opt opt;
#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 ca871b13524e..93e7fee42cd4 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -167,7 +167,9 @@ 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,
+ enum kernel_pread_opt opt)
{
struct fw_priv *fw_priv;

@@ -185,6 +187,8 @@ 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 = opt;
fw_state_init(fw_priv);
#ifdef CONFIG_FW_LOADER_USER_HELPER
INIT_LIST_HEAD(&fw_priv->pending_list);
@@ -210,9 +214,11 @@ static struct fw_priv *__lookup_fw_priv(const char *fw_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)
+ size_t size, u32 opt_flags,
+ size_t offset)
{
struct fw_priv *tmp;
+ enum kernel_pread_opt pread_opt;

spin_lock(&fwc->lock);
if (!(opt_flags & FW_OPT_NOCACHE)) {
@@ -226,7 +232,12 @@ static int alloc_lookup_fw_priv(const char *fw_name,
}
}

- tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size);
+ if (opt_flags & FW_OPT_PARTIAL)
+ pread_opt = KERNEL_PREAD_PART;
+ else
+ pread_opt = KERNEL_PREAD_WHOLE;
+
+ tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, offset, pread_opt);
if (tmp) {
INIT_LIST_HEAD(&tmp->list);
if (!(opt_flags & FW_OPT_NOCACHE))
@@ -495,8 +506,10 @@ 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, fw_priv->offset,
+ msize,
+ fw_priv->opt, id);
if (rc) {
if (rc != -ENOENT)
dev_warn(device, "loading %s failed with error %d\n",
@@ -683,7 +696,7 @@ 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)
+ u32 opt_flags, size_t offset)
{
struct firmware *firmware;
struct fw_priv *fw_priv;
@@ -702,7 +715,7 @@ _request_firmware_prepare(struct firmware **firmware_p, const char *name,
}

ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size,
- opt_flags);
+ opt_flags, offset);

/*
* bind with 'priv' now to avoid warning in failure path
@@ -749,7 +762,7 @@ 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)
+ u32 opt_flags, size_t offset)
{
struct firmware *fw = NULL;
int ret;
@@ -763,7 +776,7 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
}

ret = _request_firmware_prepare(&fw, name, device, buf, size,
- opt_flags);
+ opt_flags, offset);
if (ret <= 0) /* error or already assigned */
goto out;

@@ -826,7 +839,7 @@ 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,
- FW_OPT_UEVENT);
+ FW_OPT_UEVENT, 0);
module_put(THIS_MODULE);
return ret;
}
@@ -853,7 +866,7 @@ 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,
- FW_OPT_UEVENT | FW_OPT_NO_WARN);
+ FW_OPT_UEVENT | FW_OPT_NO_WARN, 0);
module_put(THIS_MODULE);
return ret;
}
@@ -878,7 +891,7 @@ int request_firmware_direct(const struct firmware **firmware_p,
__module_get(THIS_MODULE);
ret = _request_firmware(firmware_p, name, device, NULL, 0,
FW_OPT_UEVENT | FW_OPT_NO_WARN |
- FW_OPT_NOFALLBACK_SYSFS);
+ FW_OPT_NOFALLBACK_SYSFS, 0);
module_put(THIS_MODULE);
return ret;
}
@@ -902,7 +915,7 @@ 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,
- FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
+ FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM, 0);
module_put(THIS_MODULE);
return ret;
}
@@ -939,6 +952,8 @@ EXPORT_SYMBOL_GPL(firmware_request_cache);
* @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
+ * @pread_opt: KERNEL_PREAD_PART to allow partial file read
*
* This function works pretty much like request_firmware(), but it doesn't
* allocate a buffer to hold the firmware data. Instead, the firmware
@@ -949,16 +964,22 @@ EXPORT_SYMBOL_GPL(firmware_request_cache);
*/
int
request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
- struct device *device, void *buf, size_t size)
+ struct device *device, void *buf, size_t size,
+ size_t offset, enum kernel_pread_opt pread_opt)
{
int ret;
+ u32 opt_flags;

if (fw_cache_is_setup(device, name))
return -EOPNOTSUPP;

__module_get(THIS_MODULE);
+ opt_flags = FW_OPT_UEVENT | FW_OPT_NOCACHE;
+ if (pread_opt == KERNEL_PREAD_PART)
+ opt_flags |= FW_OPT_PARTIAL;
+
ret = _request_firmware(firmware_p, name, device, buf, size,
- FW_OPT_UEVENT | FW_OPT_NOCACHE);
+ opt_flags, offset);
module_put(THIS_MODULE);
return ret;
}
@@ -997,7 +1018,7 @@ 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,
- fw_work->opt_flags);
+ fw_work->opt_flags, 0);
fw_work->cont(fw, fw_work->context);
put_device(fw_work->device); /* taken in request_firmware_nowait() */

diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c
index 24cd193dec55..c9490c15da68 100644
--- a/drivers/soc/qcom/mdt_loader.c
+++ b/drivers/soc/qcom/mdt_loader.c
@@ -246,8 +246,11 @@ static int __qcom_mdt_load(struct device *dev, const struct firmware *fw,
} else if (phdr->p_filesz) {
/* Firmware not large enough, load split-out segments */
sprintf(fw_name + fw_name_len - 3, "b%02d", i);
- ret = request_firmware_into_buf(&seg_fw, fw_name, dev,
- ptr, phdr->p_filesz);
+ ret = request_firmware_into_buf
+ (&seg_fw, fw_name, dev,
+ ptr, phdr->p_filesz,
+ 0,
+ KERNEL_PREAD_WHOLE);
if (ret) {
dev_err(dev, "failed to load %s\n", fw_name);
break;
diff --git a/include/linux/firmware.h b/include/linux/firmware.h
index cb3e2c06ed8a..a53a854294e2 100644
--- a/include/linux/firmware.h
+++ b/include/linux/firmware.h
@@ -4,6 +4,7 @@

#include <linux/types.h>
#include <linux/compiler.h>
+#include <linux/fs.h>
#include <linux/gfp.h>

#define FW_ACTION_NOHOTPLUG 0
@@ -52,7 +53,9 @@ int request_firmware_nowait(
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);
+ const char *name, struct device *device,
+ void *buf, size_t size,
+ size_t offset, enum kernel_pread_opt opt);

void release_firmware(const struct firmware *fw);
#else
@@ -97,7 +100,8 @@ static inline int request_firmware_direct(const struct firmware **fw,
}

static inline int request_firmware_into_buf(const struct firmware **firmware_p,
- const char *name, struct device *device, void *buf, size_t size)
+ const char *name, struct device *device, void *buf, size_t size,
+ size_t offset, enum kernel_pread_opt opt)
{
return -EINVAL;
}
diff --git a/lib/test_firmware.c b/lib/test_firmware.c
index 9fee2b93a8d1..af747660fe29 100644
--- a/lib/test_firmware.c
+++ b/lib/test_firmware.c
@@ -654,7 +654,9 @@ static int test_fw_run_batch_request(void *data)
req->name,
req->dev,
test_buf,
- TEST_FIRMWARE_BUF_SIZE);
+ TEST_FIRMWARE_BUF_SIZE,
+ 0,
+ KERNEL_PREAD_WHOLE);
if (!req->fw)
kfree(test_buf);
} else {
--
2.17.1