[PATCH] usb-storage: Use const to reduce object data size

From: Joe Perches
Date: Fri Feb 14 2020 - 13:17:20 EST


Make structs const to reduce data size ~20KB.

Change function arguments and prototypes as necessary to compile.

$ size (x86-64 defconfig pre)
text data bss dec hex filename
12281 10948 480 23709 5c9d ./drivers/usb/storage/usb.o
111 10528 8 10647 2997 ./drivers/usb/storage/usual-tables.o

$ size (x86-64 defconfig post)
text data bss dec hex filename
22809 420 480 23709 5c9d drivers/usb/storage/usb.o
10551 0 0 10551 2937 drivers/usb/storage/usual-tables.o

Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---

compile tested only

drivers/usb/storage/usb.c | 10 +++++-----
drivers/usb/storage/usb.h | 5 +++--
drivers/usb/storage/usual-tables.c | 6 +++---
include/linux/usb_usual.h | 2 +-
4 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index 9a79cd..94a6472 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -121,12 +121,12 @@ MODULE_PARM_DESC(quirks, "supplemental list of
device IDs and their quirks");
.initFunction = init_function, \
}

-static struct us_unusual_dev us_unusual_dev_list[] = {
+static const struct us_unusual_dev us_unusual_dev_list[] = {
# include "unusual_devs.h"
{ } /* Terminating entry */
};

-static struct us_unusual_dev for_dynamic_ids =
+static const struct us_unusual_dev for_dynamic_ids =
USUAL_DEV(USB_SC_SCSI, USB_PR_BULK);

#undef UNUSUAL_DEV
@@ -583,7 +583,7 @@ EXPORT_SYMBOL_GPL(usb_stor_adjust_quirks);

/* Get the unusual_devs entries and the string descriptors */
static int get_device_info(struct us_data *us, const struct
usb_device_id *id,
- struct us_unusual_dev *unusual_dev)
+ const struct us_unusual_dev *unusual_dev)
{
struct usb_device *dev = us->pusb_dev;
struct usb_interface_descriptor *idesc =
@@ -933,7 +933,7 @@ static unsigned int usb_stor_sg_tablesize(struct
usb_interface *intf)
int usb_stor_probe1(struct us_data **pus,
struct usb_interface *intf,
const struct usb_device_id *id,
- struct us_unusual_dev *unusual_dev,
+ const struct us_unusual_dev *unusual_dev,
struct scsi_host_template *sht)
{
struct Scsi_Host *host;
@@ -1092,7 +1092,7 @@ static struct scsi_host_template
usb_stor_host_template;
static int storage_probe(struct usb_interface *intf,
const struct usb_device_id *id)
{
- struct us_unusual_dev *unusual_dev;
+ const struct us_unusual_dev *unusual_dev;
struct us_data *us;
int result;
int size;
diff --git a/drivers/usb/storage/usb.h b/drivers/usb/storage/usb.h
index 85052c..5850d62 100644
--- a/drivers/usb/storage/usb.h
+++ b/drivers/usb/storage/usb.h
@@ -93,7 +93,8 @@ struct us_data {
struct mutex dev_mutex; /* protect pusb_dev */
struct usb_device *pusb_dev; /* this usb_device */
struct usb_interface *pusb_intf; /* this interface */
- struct us_unusual_dev *unusual_dev; /* device-filter
entry */
+ const struct us_unusual_dev *unusual_dev;
+ /* device-filter
entry */
unsigned long fflags; /* fixed flags from
filter */
unsigned long dflags; /* dynamic atomic
bitflags */
unsigned int send_bulk_pipe; /* cached pipe values
*/
@@ -185,7 +186,7 @@ extern int usb_stor_post_reset(struct usb_interface
*iface);
extern int usb_stor_probe1(struct us_data **pus,
struct usb_interface *intf,
const struct usb_device_id *id,
- struct us_unusual_dev *unusual_dev,
+ const struct us_unusual_dev *unusual_dev,
struct scsi_host_template *sht);
extern int usb_stor_probe2(struct us_data *us);
extern void usb_stor_disconnect(struct usb_interface *intf);
diff --git a/drivers/usb/storage/usual-tables.c
b/drivers/usb/storage/usual-tables.c
index cfd12e5..529512 100644
--- a/drivers/usb/storage/usual-tables.c
+++ b/drivers/usb/storage/usual-tables.c
@@ -40,7 +40,7 @@
.driver_info = (flags) \
}

-struct usb_device_id usb_storage_usb_ids[] = {
+const struct usb_device_id usb_storage_usb_ids[] = {
# include "unusual_devs.h"
{ } /* Terminating entry */
};
@@ -68,7 +68,7 @@ struct ignore_entry {
.bcdmax = bcdDeviceMax, \
}

-static struct ignore_entry ignore_ids[] = {
+static const struct ignore_entry ignore_ids[] = {
# include "unusual_alauda.h"
# include "unusual_cypress.h"
# include "unusual_datafab.h"
@@ -92,7 +92,7 @@ int usb_usual_ignore_device(struct usb_interface
*intf)
{
struct usb_device *udev;
unsigned vid, pid, bcd;
- struct ignore_entry *p;
+ const struct ignore_entry *p;

udev = interface_to_usbdev(intf);
vid = le16_to_cpu(udev->descriptor.idVendor);
diff --git a/include/linux/usb_usual.h b/include/linux/usb_usual.h
index 000a595..4a19ac3 100644
--- a/include/linux/usb_usual.h
+++ b/include/linux/usb_usual.h
@@ -92,6 +92,6 @@ enum { US_DO_ALL_FLAGS };
#include <linux/usb/storage.h>

extern int usb_usual_ignore_device(struct usb_interface *intf);
-extern struct usb_device_id usb_storage_usb_ids[];
+extern const struct usb_device_id usb_storage_usb_ids[];

#endif /* __LINUX_USB_USUAL_H */