The main purpose of this series is to report the CAN controller
capabilities. The proposed method reuses the existing struct
can_ctrlmode and thus do not need a new IFLA_CAN_* entry.
While doing so, I also realized that can_priv::ctrlmode_static could
actually be derived from the other ctrlmode fields. So I added three
extra patches to the series: one to replace that field with a
function, one to add a safeguard on can_set_static_ctrlmode() and one
to repack struct can_priv and fill the hole created after removing
can_priv::ctrlmode_priv.
Please note that the first three patches are not required by the
fourth one. I am just grouping everything in the same series because
the patches all revolve around the controller modes.
** Changelog **
v5 -> v6:
- Add back patches 1, 2 and 3 because those were removed from the
testing branch of linux-can-next since.
- Rebase the series on the latest version of net-next.
- Fix a typo in the comments of the forth patch: guaruanty ->
guaranty.
v4 -> v5:
- Implement IFLA_CAN_CTRLMODE_EXT in order to fix forward
compatibility issues as suggested by Marc in:
https://lore.kernel.org/linux-can/[email protected]/T/#m78118c94072083a6f8d2f0f769b120f847ac1384
v3 -> v4:
- Tag the union in struct can_ctrlmode as packed.
- Remove patch 1, 2 and 3 from the series because those were already
added to the testing branch of linux-can-next (and no changes
occurred on those first three patches).
v2 -> v3:
- Make can_set_static_ctrlmode() return an error and adjust the
drivers which use this helper function accordingly.
v1 -> v2:
- Add a first patch to replace can_priv::ctrlmode_static by the
inline function can_get_static_ctrlmode()
- Add a second patch to reorder the fields of struct can_priv for
better packing (save eight bytes on x86_64 \o/)
- Rewrite the comments of the third patch "can: netlink: report the
CAN controller mode supported flags" (no changes on the code
itself).
Vincent Mailhol (4):
can: dev: replace can_priv::ctrlmode_static by
can_get_static_ctrlmode()
can: dev: add sanity check in can_set_static_ctrlmode()
can: dev: reorder struct can_priv members for better packing
can: netlink: report the CAN controller mode supported flags
drivers/net/can/dev/dev.c | 5 +++--
drivers/net/can/dev/netlink.c | 33 +++++++++++++++++++++++++++++--
drivers/net/can/m_can/m_can.c | 10 +++++++---
drivers/net/can/rcar/rcar_canfd.c | 4 +++-
include/linux/can/dev.h | 24 +++++++++++++++-------
include/uapi/linux/can/netlink.h | 13 ++++++++++++
6 files changed, 74 insertions(+), 15 deletions(-)
base-commit: 64445dda9d8384975eca54e3f01886fca61e1db6
prerequisite-patch-id: 84ffb60366d113cfbf6fb8e415217d9e09fadefd
--
2.32.0
The statically enabled features of a CAN controller can be retrieved
using below formula:
| u32 ctrlmode_static = priv->ctrlmode & ~priv->ctrlmode_supported;
As such, there is no need to store this information. This patch remove
the field ctrlmode_static of struct can_priv and provides, in
replacement, the inline function can_get_static_ctrlmode() which
returns the same value.
Signed-off-by: Vincent Mailhol <[email protected]>
---
drivers/net/can/dev/dev.c | 5 +++--
drivers/net/can/dev/netlink.c | 2 +-
include/linux/can/dev.h | 7 +++++--
3 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
index e3d840b81357..59c79f92fccc 100644
--- a/drivers/net/can/dev/dev.c
+++ b/drivers/net/can/dev/dev.c
@@ -300,6 +300,7 @@ EXPORT_SYMBOL_GPL(free_candev);
int can_change_mtu(struct net_device *dev, int new_mtu)
{
struct can_priv *priv = netdev_priv(dev);
+ u32 ctrlmode_static = can_get_static_ctrlmode(priv);
/* Do not allow changing the MTU while running */
if (dev->flags & IFF_UP)
@@ -309,7 +310,7 @@ int can_change_mtu(struct net_device *dev, int new_mtu)
switch (new_mtu) {
case CAN_MTU:
/* 'CANFD-only' controllers can not switch to CAN_MTU */
- if (priv->ctrlmode_static & CAN_CTRLMODE_FD)
+ if (ctrlmode_static & CAN_CTRLMODE_FD)
return -EINVAL;
priv->ctrlmode &= ~CAN_CTRLMODE_FD;
@@ -318,7 +319,7 @@ int can_change_mtu(struct net_device *dev, int new_mtu)
case CANFD_MTU:
/* check for potential CANFD ability */
if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) &&
- !(priv->ctrlmode_static & CAN_CTRLMODE_FD))
+ !(ctrlmode_static & CAN_CTRLMODE_FD))
return -EINVAL;
priv->ctrlmode |= CAN_CTRLMODE_FD;
diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c
index 95cca4e5251f..26c336808be5 100644
--- a/drivers/net/can/dev/netlink.c
+++ b/drivers/net/can/dev/netlink.c
@@ -211,7 +211,7 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[],
if (dev->flags & IFF_UP)
return -EBUSY;
cm = nla_data(data[IFLA_CAN_CTRLMODE]);
- ctrlstatic = priv->ctrlmode_static;
+ ctrlstatic = can_get_static_ctrlmode(priv);
maskedflags = cm->flags & cm->mask;
/* check whether provided bits are allowed to be passed */
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 45f19d9db5ca..92e2d69462f0 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -69,7 +69,6 @@ struct can_priv {
/* CAN controller features - see include/uapi/linux/can/netlink.h */
u32 ctrlmode; /* current options setting */
u32 ctrlmode_supported; /* options that can be modified by netlink */
- u32 ctrlmode_static; /* static enabled options for driver/hardware */
int restart_ms;
struct delayed_work restart_work;
@@ -139,13 +138,17 @@ static inline void can_set_static_ctrlmode(struct net_device *dev,
/* alloc_candev() succeeded => netdev_priv() is valid at this point */
priv->ctrlmode = static_mode;
- priv->ctrlmode_static = static_mode;
/* override MTU which was set by default in can_setup()? */
if (static_mode & CAN_CTRLMODE_FD)
dev->mtu = CANFD_MTU;
}
+static inline u32 can_get_static_ctrlmode(struct can_priv *priv)
+{
+ return priv->ctrlmode & ~priv->ctrlmode_supported;
+}
+
void can_setup(struct net_device *dev);
struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
--
2.32.0
Previous patch removed can_priv::ctrlmode_static to replace it with
can_get_static_ctrlmode().
A condition sine qua non for this to work is that the controller
static modes should never be set in can_priv::ctrlmode_supported
(c.f. the comment on can_priv::ctrlmode_supported which states that it
is for "options that can be *modified* by netlink"). Also, this
condition is already correctly fulfilled by all existing drivers
which rely on the ctrlmode_static feature.
Nonetheless, we added an extra safeguard in can_set_static_ctrlmode()
to return an error value and to warn the developer who would be
adventurous enough to set to static a given feature that is already
set to supported.
The drivers which rely on the static controller mode are then updated
to check the return value of can_set_static_ctrlmode().
Signed-off-by: Vincent Mailhol <[email protected]>
--
Some few comments on how the rcar_canfd and m_can drivers free their
allocated resources when an error occurs during probing.
The function rcar_canfd_channel_probe() is quite inconsistent with the
way it handles errors. After the call to alloc_candev, there are
several "goto fail" statements that would directly exit without
calling free_candev()!
Nonetheless, later on the driver will check the return value of
rcar_canfd_channel_probe() and call rcar_canfd_channel_remove() which
will correctly call free_candev(). Even if this is inconsistent, there
is no sign of a memory leak. So I just applied the change the
can_set_static_ctrlmode() without bothering more (N.B. I do not own
that device so I am not willing to take the risk of making bigger
changes because I can not test).
On the other hand, m_can_dev_setup() is fine: the return value is
checked by the caller and necessary actions are taken.
As such, for both driver, we did a minimal change.
---
drivers/net/can/m_can/m_can.c | 10 +++++++---
drivers/net/can/rcar/rcar_canfd.c | 4 +++-
include/linux/can/dev.h | 11 +++++++++--
3 files changed, 19 insertions(+), 6 deletions(-)
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index c2a8421e7845..56af9ea4694f 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -1463,7 +1463,7 @@ static bool m_can_niso_supported(struct m_can_classdev *cdev)
static int m_can_dev_setup(struct m_can_classdev *cdev)
{
struct net_device *dev = cdev->net;
- int m_can_version;
+ int m_can_version, err;
m_can_version = m_can_check_core_release(cdev);
/* return if unsupported version */
@@ -1493,7 +1493,9 @@ static int m_can_dev_setup(struct m_can_classdev *cdev)
switch (cdev->version) {
case 30:
/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */
- can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
+ err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
+ if (err)
+ return err;
cdev->can.bittiming_const = cdev->bit_timing ?
cdev->bit_timing : &m_can_bittiming_const_30X;
@@ -1503,7 +1505,9 @@ static int m_can_dev_setup(struct m_can_classdev *cdev)
break;
case 31:
/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */
- can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
+ err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
+ if (err)
+ return err;
cdev->can.bittiming_const = cdev->bit_timing ?
cdev->bit_timing : &m_can_bittiming_const_31X;
diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index ff9d0f5ae0dd..e225c1c03812 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -1706,7 +1706,9 @@ static int rcar_canfd_channel_probe(struct rcar_canfd_global *gpriv, u32 ch,
&rcar_canfd_data_bittiming_const;
/* Controller starts in CAN FD only mode */
- can_set_static_ctrlmode(ndev, CAN_CTRLMODE_FD);
+ err = can_set_static_ctrlmode(ndev, CAN_CTRLMODE_FD);
+ if (err)
+ goto fail;
priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING;
} else {
/* Controller starts in Classical CAN only mode */
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 92e2d69462f0..fff3f70df697 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -131,17 +131,24 @@ static inline s32 can_get_relative_tdco(const struct can_priv *priv)
}
/* helper to define static CAN controller features at device creation time */
-static inline void can_set_static_ctrlmode(struct net_device *dev,
- u32 static_mode)
+static inline int __must_check can_set_static_ctrlmode(struct net_device *dev,
+ u32 static_mode)
{
struct can_priv *priv = netdev_priv(dev);
/* alloc_candev() succeeded => netdev_priv() is valid at this point */
+ if (priv->ctrlmode_supported & static_mode) {
+ netdev_warn(dev,
+ "Controller features can not be supported and static at the same time\n");
+ return -EINVAL;
+ }
priv->ctrlmode = static_mode;
/* override MTU which was set by default in can_setup()? */
if (static_mode & CAN_CTRLMODE_FD)
dev->mtu = CANFD_MTU;
+
+ return 0;
}
static inline u32 can_get_static_ctrlmode(struct can_priv *priv)
--
2.32.0
Save eight bytes of holes on x86-64 architectures by reordering the
members of struct can_priv.
Before:
| $ pahole -C can_priv drivers/net/can/dev/dev.o
| struct can_priv {
| struct net_device * dev; /* 0 8 */
| struct can_device_stats can_stats; /* 8 24 */
| const struct can_bittiming_const * bittiming_const; /* 32 8 */
| const struct can_bittiming_const * data_bittiming_const; /* 40 8 */
| struct can_bittiming bittiming; /* 48 32 */
| /* --- cacheline 1 boundary (64 bytes) was 16 bytes ago --- */
| struct can_bittiming data_bittiming; /* 80 32 */
| const struct can_tdc_const * tdc_const; /* 112 8 */
| struct can_tdc tdc; /* 120 12 */
| /* --- cacheline 2 boundary (128 bytes) was 4 bytes ago --- */
| unsigned int bitrate_const_cnt; /* 132 4 */
| const u32 * bitrate_const; /* 136 8 */
| const u32 * data_bitrate_const; /* 144 8 */
| unsigned int data_bitrate_const_cnt; /* 152 4 */
| u32 bitrate_max; /* 156 4 */
| struct can_clock clock; /* 160 4 */
| unsigned int termination_const_cnt; /* 164 4 */
| const u16 * termination_const; /* 168 8 */
| u16 termination; /* 176 2 */
|
| /* XXX 6 bytes hole, try to pack */
|
| struct gpio_desc * termination_gpio; /* 184 8 */
| /* --- cacheline 3 boundary (192 bytes) --- */
| u16 termination_gpio_ohms[2]; /* 192 4 */
| enum can_state state; /* 196 4 */
| u32 ctrlmode; /* 200 4 */
| u32 ctrlmode_supported; /* 204 4 */
| int restart_ms; /* 208 4 */
|
| /* XXX 4 bytes hole, try to pack */
|
| struct delayed_work restart_work; /* 216 88 */
|
| /* XXX last struct has 4 bytes of padding */
|
| /* --- cacheline 4 boundary (256 bytes) was 48 bytes ago --- */
| int (*do_set_bittiming)(struct net_device *); /* 304 8 */
| int (*do_set_data_bittiming)(struct net_device *); /* 312 8 */
| /* --- cacheline 5 boundary (320 bytes) --- */
| int (*do_set_mode)(struct net_device *, enum can_mode); /* 320 8 */
| int (*do_set_termination)(struct net_device *, u16); /* 328 8 */
| int (*do_get_state)(const struct net_device *, enum can_state *); /* 336 8 */
| int (*do_get_berr_counter)(const struct net_device *, struct can_berr_counter *); /* 344 8 */
| unsigned int echo_skb_max; /* 352 4 */
|
| /* XXX 4 bytes hole, try to pack */
|
| struct sk_buff * * echo_skb; /* 360 8 */
|
| /* size: 368, cachelines: 6, members: 32 */
| /* sum members: 354, holes: 3, sum holes: 14 */
| /* paddings: 1, sum paddings: 4 */
| /* last cacheline: 48 bytes */
| };
After:
| $ pahole -C can_priv drivers/net/can/dev/dev.o
| struct can_priv {
| struct net_device * dev; /* 0 8 */
| struct can_device_stats can_stats; /* 8 24 */
| const struct can_bittiming_const * bittiming_const; /* 32 8 */
| const struct can_bittiming_const * data_bittiming_const; /* 40 8 */
| struct can_bittiming bittiming; /* 48 32 */
| /* --- cacheline 1 boundary (64 bytes) was 16 bytes ago --- */
| struct can_bittiming data_bittiming; /* 80 32 */
| const struct can_tdc_const * tdc_const; /* 112 8 */
| struct can_tdc tdc; /* 120 12 */
| /* --- cacheline 2 boundary (128 bytes) was 4 bytes ago --- */
| unsigned int bitrate_const_cnt; /* 132 4 */
| const u32 * bitrate_const; /* 136 8 */
| const u32 * data_bitrate_const; /* 144 8 */
| unsigned int data_bitrate_const_cnt; /* 152 4 */
| u32 bitrate_max; /* 156 4 */
| struct can_clock clock; /* 160 4 */
| unsigned int termination_const_cnt; /* 164 4 */
| const u16 * termination_const; /* 168 8 */
| u16 termination; /* 176 2 */
|
| /* XXX 6 bytes hole, try to pack */
|
| struct gpio_desc * termination_gpio; /* 184 8 */
| /* --- cacheline 3 boundary (192 bytes) --- */
| u16 termination_gpio_ohms[2]; /* 192 4 */
| unsigned int echo_skb_max; /* 196 4 */
| struct sk_buff * * echo_skb; /* 200 8 */
| enum can_state state; /* 208 4 */
| u32 ctrlmode; /* 212 4 */
| u32 ctrlmode_supported; /* 216 4 */
| int restart_ms; /* 220 4 */
| struct delayed_work restart_work; /* 224 88 */
|
| /* XXX last struct has 4 bytes of padding */
|
| /* --- cacheline 4 boundary (256 bytes) was 56 bytes ago --- */
| int (*do_set_bittiming)(struct net_device *); /* 312 8 */
| /* --- cacheline 5 boundary (320 bytes) --- */
| int (*do_set_data_bittiming)(struct net_device *); /* 320 8 */
| int (*do_set_mode)(struct net_device *, enum can_mode); /* 328 8 */
| int (*do_set_termination)(struct net_device *, u16); /* 336 8 */
| int (*do_get_state)(const struct net_device *, enum can_state *); /* 344 8 */
| int (*do_get_berr_counter)(const struct net_device *, struct can_berr_counter *); /* 352 8 */
|
| /* size: 360, cachelines: 6, members: 32 */
| /* sum members: 354, holes: 1, sum holes: 6 */
| /* paddings: 1, sum paddings: 4 */
| /* last cacheline: 40 bytes */
| };
Signed-off-by: Vincent Mailhol <[email protected]>
---
include/linux/can/dev.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index fff3f70df697..c2ea47f30046 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -64,6 +64,9 @@ struct can_priv {
struct gpio_desc *termination_gpio;
u16 termination_gpio_ohms[CAN_TERMINATION_GPIO_MAX];
+ unsigned int echo_skb_max;
+ struct sk_buff **echo_skb;
+
enum can_state state;
/* CAN controller features - see include/uapi/linux/can/netlink.h */
@@ -83,9 +86,6 @@ struct can_priv {
struct can_berr_counter *bec);
int (*do_get_auto_tdcv)(const struct net_device *dev, u32 *tdcv);
- unsigned int echo_skb_max;
- struct sk_buff **echo_skb;
-
#ifdef CONFIG_CAN_LEDS
struct led_trigger *tx_led_trig;
char tx_led_trig_name[CAN_LED_NAME_SZ];
--
2.32.0
Currently, the CAN netlink interface provides no easy ways to check
the capabilities of a given controller. The only method from the
command line is to try each CAN_CTRLMODE_* individually to check
whether the netlink interface returns an -EOPNOTSUPP error or not
(alternatively, one may find it easier to directly check the source
code of the driver instead...)
This patch introduces a method for the user to check both the
supported and the static capabilities. The proposed method introduces
a new IFLA nest: IFLA_CAN_CTRLMODE_EXT which extends the current
IFLA_CAN_CTRLMODE. This is done to guaranty a full forward and
backward compatibility between the kernel and the user land
applications.
The IFLA_CAN_CTRLMODE_EXT nest contains one single entry:
IFLA_CAN_CTRLMODE_SUPPORTED. Because this entry is only used in one
direction: kernel to userland, no new struct nla_policy are
introduced.
Below table explains how IFLA_CAN_CTRLMODE_SUPPORTED (hereafter:
"supported") and can_ctrlmode::flags (hereafter: "flags") allow us to
identify both the supported and the static capabilities, when masked
with any of the CAN_CTRLMODE_* bit flags:
supported & flags & Controller capabilities
CAN_CTRLMODE_* CAN_CTRLMODE_*
-----------------------------------------------------------------------
false false Feature not supported (always disabled)
false true Static feature (always enabled)
true false Feature supported but disabled
true true Feature supported and enabled
Signed-off-by: Vincent Mailhol <[email protected]>
---
drivers/net/can/dev/netlink.c | 31 ++++++++++++++++++++++++++++++-
include/uapi/linux/can/netlink.h | 13 +++++++++++++
2 files changed, 43 insertions(+), 1 deletion(-)
diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c
index 26c336808be5..7633d98e3912 100644
--- a/drivers/net/can/dev/netlink.c
+++ b/drivers/net/can/dev/netlink.c
@@ -21,6 +21,7 @@ static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
[IFLA_CAN_DATA_BITTIMING_CONST] = { .len = sizeof(struct can_bittiming_const) },
[IFLA_CAN_TERMINATION] = { .type = NLA_U16 },
[IFLA_CAN_TDC] = { .type = NLA_NESTED },
+ [IFLA_CAN_CTRLMODE_EXT] = { .type = NLA_NESTED },
};
static const struct nla_policy can_tdc_policy[IFLA_CAN_TDC_MAX + 1] = {
@@ -383,6 +384,12 @@ static size_t can_tdc_get_size(const struct net_device *dev)
return size;
}
+static size_t can_ctrlmode_ext_get_size(void)
+{
+ return nla_total_size(0) + /* nest IFLA_CAN_CTRLMODE_EXT */
+ nla_total_size(sizeof(u32)); /* IFLA_CAN_CTRLMODE_SUPPORTED */
+}
+
static size_t can_get_size(const struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
@@ -415,6 +422,7 @@ static size_t can_get_size(const struct net_device *dev)
priv->data_bitrate_const_cnt);
size += sizeof(priv->bitrate_max); /* IFLA_CAN_BITRATE_MAX */
size += can_tdc_get_size(dev); /* IFLA_CAN_TDC */
+ size += can_ctrlmode_ext_get_size(); /* IFLA_CAN_CTRLMODE_EXT */
return size;
}
@@ -472,6 +480,25 @@ static int can_tdc_fill_info(struct sk_buff *skb, const struct net_device *dev)
return -EMSGSIZE;
}
+static int can_ctrlmode_ext_fill_info(struct sk_buff *skb,
+ const struct can_priv *priv)
+{
+ struct nlattr *nest;
+
+ nest = nla_nest_start(skb, IFLA_CAN_CTRLMODE_EXT);
+ if (!nest)
+ return -EMSGSIZE;
+
+ if (nla_put_u32(skb, IFLA_CAN_CTRLMODE_SUPPORTED,
+ priv->ctrlmode_supported)) {
+ nla_nest_cancel(skb, nest);
+ return -EMSGSIZE;
+ }
+
+ nla_nest_end(skb, nest);
+ return 0;
+}
+
static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
@@ -531,7 +558,9 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
sizeof(priv->bitrate_max),
&priv->bitrate_max)) ||
- (can_tdc_fill_info(skb, dev))
+ can_tdc_fill_info(skb, dev) ||
+
+ can_ctrlmode_ext_fill_info(skb, priv)
)
return -EMSGSIZE;
diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h
index 75b85c60efb2..02ec32d69474 100644
--- a/include/uapi/linux/can/netlink.h
+++ b/include/uapi/linux/can/netlink.h
@@ -137,6 +137,7 @@ enum {
IFLA_CAN_DATA_BITRATE_CONST,
IFLA_CAN_BITRATE_MAX,
IFLA_CAN_TDC,
+ IFLA_CAN_CTRLMODE_EXT,
/* add new constants above here */
__IFLA_CAN_MAX,
@@ -166,6 +167,18 @@ enum {
IFLA_CAN_TDC_MAX = __IFLA_CAN_TDC - 1
};
+/*
+ * IFLA_CAN_CTRLMODE_EXT nest: controller mode extended parameters
+ */
+enum {
+ IFLA_CAN_CTRLMODE_UNSPEC,
+ IFLA_CAN_CTRLMODE_SUPPORTED, /* u32 */
+
+ /* add new constants above here */
+ __IFLA_CAN_CTRLMODE,
+ IFLA_CAN_CTRLMODE_MAX = __IFLA_CAN_CTRLMODE - 1
+};
+
/* u16 termination range: 1..65535 Ohms */
#define CAN_TERMINATION_DISABLED 0
--
2.32.0
On Tue. 14 Dec 2021 at 01:02, Vincent Mailhol
<[email protected]> wrote:
> The main purpose of this series is to report the CAN controller
> capabilities. The proposed method reuses the existing struct
> can_ctrlmode and thus do not need a new IFLA_CAN_* entry.
I forgot to update this part of the cover letter since v4.
This paragraph is outdated and should now be:
| The main purpose of this series is to report the CAN controller
| capabilities. To do so, a new IFLA_CAN_* entry is
| added: IFLA_CAN_CTRLMODE_EXT. This is done to guarantee forward
| and backward compatibility in the netlink interface.
N.B. I do not plan to send a v7 because the patch descriptions
are correct (only the cover letter was outdated).
> While doing so, I also realized that can_priv::ctrlmode_static could
> actually be derived from the other ctrlmode fields. So I added three
> extra patches to the series: one to replace that field with a
> function, one to add a safeguard on can_set_static_ctrlmode() and one
> to repack struct can_priv and fill the hole created after removing
> can_priv::ctrlmode_priv.
>
> Please note that the first three patches are not required by the
> fourth one. I am just grouping everything in the same series because
> the patches all revolve around the controller modes.
>
>
> ** Changelog **
>
> v5 -> v6:
>
> - Add back patches 1, 2 and 3 because those were removed from the
> testing branch of linux-can-next since.
>
> - Rebase the series on the latest version of net-next.
>
> - Fix a typo in the comments of the forth patch: guaruanty ->
> guaranty.
>
> v4 -> v5:
>
> - Implement IFLA_CAN_CTRLMODE_EXT in order to fix forward
> compatibility issues as suggested by Marc in:
> https://lore.kernel.org/linux-can/[email protected]/T/#m78118c94072083a6f8d2f0f769b120f847ac1384
>
> v3 -> v4:
>
> - Tag the union in struct can_ctrlmode as packed.
>
> - Remove patch 1, 2 and 3 from the series because those were already
> added to the testing branch of linux-can-next (and no changes
> occurred on those first three patches).
>
> v2 -> v3:
>
> - Make can_set_static_ctrlmode() return an error and adjust the
> drivers which use this helper function accordingly.
>
> v1 -> v2:
>
> - Add a first patch to replace can_priv::ctrlmode_static by the
> inline function can_get_static_ctrlmode()
>
> - Add a second patch to reorder the fields of struct can_priv for
> better packing (save eight bytes on x86_64 \o/)
>
> - Rewrite the comments of the third patch "can: netlink: report the
> CAN controller mode supported flags" (no changes on the code
> itself).
>
> Vincent Mailhol (4):
> can: dev: replace can_priv::ctrlmode_static by
> can_get_static_ctrlmode()
> can: dev: add sanity check in can_set_static_ctrlmode()
> can: dev: reorder struct can_priv members for better packing
> can: netlink: report the CAN controller mode supported flags
>
> drivers/net/can/dev/dev.c | 5 +++--
> drivers/net/can/dev/netlink.c | 33 +++++++++++++++++++++++++++++--
> drivers/net/can/m_can/m_can.c | 10 +++++++---
> drivers/net/can/rcar/rcar_canfd.c | 4 +++-
> include/linux/can/dev.h | 24 +++++++++++++++-------
> include/uapi/linux/can/netlink.h | 13 ++++++++++++
> 6 files changed, 74 insertions(+), 15 deletions(-)
>
>
> base-commit: 64445dda9d8384975eca54e3f01886fca61e1db6
> prerequisite-patch-id: 84ffb60366d113cfbf6fb8e415217d9e09fadefd
> --
> 2.32.0
>