[PATCH] usb: musb: Constify struct musb_fifo_cfg

From: Christophe JAILLET
Date: Sat Jan 18 2025 - 16:12:03 EST


'struct musb_fifo_cfg' are not modified in these drivers.

Constifying these structures moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig, as an example:
Before:
======
text data bss dec hex filename
64381 5537 202 70120 111e8 drivers/usb/musb/musb_core.o

After:
=====
text data bss dec hex filename
64957 4929 202 70088 111c8 drivers/usb/musb/musb_core.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
Compile tested-only.
---
.../driver-api/usb/writing_musb_glue_layer.rst | 2 +-
drivers/usb/musb/jz4740.c | 4 ++--
drivers/usb/musb/mediatek.c | 2 +-
drivers/usb/musb/mpfs.c | 2 +-
drivers/usb/musb/musb_core.c | 14 +++++++-------
drivers/usb/musb/sunxi.c | 4 ++--
include/linux/usb/musb.h | 2 +-
7 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/Documentation/driver-api/usb/writing_musb_glue_layer.rst b/Documentation/driver-api/usb/writing_musb_glue_layer.rst
index e755c8551bba..0bb96ecdf527 100644
--- a/Documentation/driver-api/usb/writing_musb_glue_layer.rst
+++ b/Documentation/driver-api/usb/writing_musb_glue_layer.rst
@@ -613,7 +613,7 @@ endpoints configuration from the hardware, so we use line 12 instruction
to bypass reading the configuration from silicon, and rely on a
hard-coded table that describes the endpoints configuration instead::

- static struct musb_fifo_cfg jz4740_musb_fifo_cfg[] = {
+ static const struct musb_fifo_cfg jz4740_musb_fifo_cfg[] = {
{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 64, },
diff --git a/drivers/usb/musb/jz4740.c b/drivers/usb/musb/jz4740.c
index acdeb1117cd3..df56c972986f 100644
--- a/drivers/usb/musb/jz4740.c
+++ b/drivers/usb/musb/jz4740.c
@@ -59,7 +59,7 @@ static irqreturn_t jz4740_musb_interrupt(int irq, void *__hci)
return IRQ_NONE;
}

-static struct musb_fifo_cfg jz4740_musb_fifo_cfg[] = {
+static const struct musb_fifo_cfg jz4740_musb_fifo_cfg[] = {
{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 64, },
@@ -205,7 +205,7 @@ static const struct musb_hdrc_platform_data jz4740_musb_pdata = {
.platform_ops = &jz4740_musb_ops,
};

-static struct musb_fifo_cfg jz4770_musb_fifo_cfg[] = {
+static const struct musb_fifo_cfg jz4770_musb_fifo_cfg[] = {
{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 512, },
diff --git a/drivers/usb/musb/mediatek.c b/drivers/usb/musb/mediatek.c
index aa988d74b58d..c6cbe718b1da 100644
--- a/drivers/usb/musb/mediatek.c
+++ b/drivers/usb/musb/mediatek.c
@@ -365,7 +365,7 @@ static const struct musb_platform_ops mtk_musb_ops = {
#define MTK_MUSB_MAX_EP_NUM 8
#define MTK_MUSB_RAM_BITS 11

-static struct musb_fifo_cfg mtk_musb_mode_cfg[] = {
+static const struct musb_fifo_cfg mtk_musb_mode_cfg[] = {
{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 512, },
diff --git a/drivers/usb/musb/mpfs.c b/drivers/usb/musb/mpfs.c
index 7edc8429b274..71e4271cba75 100644
--- a/drivers/usb/musb/mpfs.c
+++ b/drivers/usb/musb/mpfs.c
@@ -29,7 +29,7 @@ struct mpfs_glue {
struct clk *clk;
};

-static struct musb_fifo_cfg mpfs_musb_mode_cfg[] = {
+static const struct musb_fifo_cfg mpfs_musb_mode_cfg[] = {
{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 512, },
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 03b1154a6014..3f11bddfa18b 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -1270,7 +1270,7 @@ MODULE_PARM_DESC(fifo_mode, "initial endpoint configuration");
*/

/* mode 0 - fits in 2KB */
-static struct musb_fifo_cfg mode_0_cfg[] = {
+static const struct musb_fifo_cfg mode_0_cfg[] = {
{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
{ .hw_ep_num = 2, .style = FIFO_RXTX, .maxpacket = 512, },
@@ -1279,7 +1279,7 @@ static struct musb_fifo_cfg mode_0_cfg[] = {
};

/* mode 1 - fits in 4KB */
-static struct musb_fifo_cfg mode_1_cfg[] = {
+static const struct musb_fifo_cfg mode_1_cfg[] = {
{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, .mode = BUF_DOUBLE, },
{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, .mode = BUF_DOUBLE, },
{ .hw_ep_num = 2, .style = FIFO_RXTX, .maxpacket = 512, .mode = BUF_DOUBLE, },
@@ -1288,7 +1288,7 @@ static struct musb_fifo_cfg mode_1_cfg[] = {
};

/* mode 2 - fits in 4KB */
-static struct musb_fifo_cfg mode_2_cfg[] = {
+static const struct musb_fifo_cfg mode_2_cfg[] = {
{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 512, },
@@ -1298,7 +1298,7 @@ static struct musb_fifo_cfg mode_2_cfg[] = {
};

/* mode 3 - fits in 4KB */
-static struct musb_fifo_cfg mode_3_cfg[] = {
+static const struct musb_fifo_cfg mode_3_cfg[] = {
{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, .mode = BUF_DOUBLE, },
{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, .mode = BUF_DOUBLE, },
{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 512, },
@@ -1308,7 +1308,7 @@ static struct musb_fifo_cfg mode_3_cfg[] = {
};

/* mode 4 - fits in 16KB */
-static struct musb_fifo_cfg mode_4_cfg[] = {
+static const struct musb_fifo_cfg mode_4_cfg[] = {
{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 512, },
@@ -1339,7 +1339,7 @@ static struct musb_fifo_cfg mode_4_cfg[] = {
};

/* mode 5 - fits in 8KB */
-static struct musb_fifo_cfg mode_5_cfg[] = {
+static const struct musb_fifo_cfg mode_5_cfg[] = {
{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 512, },
@@ -1446,7 +1446,7 @@ fifo_setup(struct musb *musb, struct musb_hw_ep *hw_ep,
return offset + (maxpacket << ((c_size & MUSB_FIFOSZ_DPB) ? 1 : 0));
}

-static struct musb_fifo_cfg ep0_cfg = {
+static const struct musb_fifo_cfg ep0_cfg = {
.style = FIFO_RXTX, .maxpacket = 64,
};

diff --git a/drivers/usb/musb/sunxi.c b/drivers/usb/musb/sunxi.c
index eac1cde86be3..a6bd3e968cc7 100644
--- a/drivers/usb/musb/sunxi.c
+++ b/drivers/usb/musb/sunxi.c
@@ -629,7 +629,7 @@ static const struct musb_platform_ops sunxi_musb_ops = {
#define SUNXI_MUSB_RAM_BITS 11

/* Allwinner OTG supports up to 5 endpoints */
-static struct musb_fifo_cfg sunxi_musb_mode_cfg_5eps[] = {
+static const struct musb_fifo_cfg sunxi_musb_mode_cfg_5eps[] = {
MUSB_EP_FIFO_SINGLE(1, FIFO_TX, 512),
MUSB_EP_FIFO_SINGLE(1, FIFO_RX, 512),
MUSB_EP_FIFO_SINGLE(2, FIFO_TX, 512),
@@ -643,7 +643,7 @@ static struct musb_fifo_cfg sunxi_musb_mode_cfg_5eps[] = {
};

/* H3/V3s OTG supports only 4 endpoints */
-static struct musb_fifo_cfg sunxi_musb_mode_cfg_4eps[] = {
+static const struct musb_fifo_cfg sunxi_musb_mode_cfg_4eps[] = {
MUSB_EP_FIFO_SINGLE(1, FIFO_TX, 512),
MUSB_EP_FIFO_SINGLE(1, FIFO_RX, 512),
MUSB_EP_FIFO_SINGLE(2, FIFO_TX, 512),
diff --git a/include/linux/usb/musb.h b/include/linux/usb/musb.h
index 3963e55e88a3..fbdef950f06c 100644
--- a/include/linux/usb/musb.h
+++ b/include/linux/usb/musb.h
@@ -61,7 +61,7 @@ struct musb_hdrc_eps_bits {
};

struct musb_hdrc_config {
- struct musb_fifo_cfg *fifo_cfg; /* board fifo configuration */
+ const struct musb_fifo_cfg *fifo_cfg; /* board fifo configuration */
unsigned fifo_cfg_size; /* size of the fifo configuration */

/* MUSB configuration-specific details */
--
2.48.1