From cc4b08c31b5c51352f258032cc65e884b3e61e6a Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Tue, 7 Dec 2021 21:15:31 +0900 Subject: can: do not increase tx_bytes statistics for RTR frames MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The actual payload length of the CAN Remote Transmission Request (RTR) frames is always 0, i.e. no payload is transmitted on the wire. However, those RTR frames still use the DLC to indicate the length of the requested frame. As such, net_device_stats::tx_bytes should not be increased when sending RTR frames. The function can_get_echo_skb() already returns the correct length, even for RTR frames (c.f. [1]). However, for historical reasons, the drivers do not use can_get_echo_skb()'s return value and instead, most of them store a temporary length (or dlc) in some local structure or array. Using the return value of can_get_echo_skb() solves the issue. After doing this, such length/dlc fields become unused and so this patch does the adequate cleaning when needed. This patch fixes all the CAN drivers. Finally, can_get_echo_skb() is decorated with the __must_check attribute in order to force future drivers to correctly use its return value (else the compiler would emit a warning). [1] commit ed3320cec279 ("can: dev: __can_get_echo_skb(): fix real payload length return value for RTR frames") Link: https://lore.kernel.org/all/20211207121531.42941-6-mailhol.vincent@wanadoo.fr Cc: Nicolas Ferre Cc: Alexandre Belloni Cc: Ludovic Desroches Cc: Maxime Ripard Cc: Chen-Yu Tsai Cc: Jernej Skrabec Cc: Yasushi SHOJI Cc: Oliver Hartkopp Cc: Stephane Grosjean Cc: Andreas Larsson Tested-by: Jimmy Assarsson # kvaser Signed-off-by: Vincent Mailhol Acked-by: Stefan Mätje # esd_usb2 Tested-by: Stefan Mätje # esd_usb2 [mkl: add conversion for grcan] Signed-off-by: Marc Kleine-Budde --- include/linux/can/skb.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h index d311bc369a39..fdb22b00674a 100644 --- a/include/linux/can/skb.h +++ b/include/linux/can/skb.h @@ -21,8 +21,9 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, unsigned int idx, unsigned int frame_len); struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr, unsigned int *frame_len_ptr); -unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx, - unsigned int *frame_len_ptr); +unsigned int __must_check can_get_echo_skb(struct net_device *dev, + unsigned int idx, + unsigned int *frame_len_ptr); void can_free_echo_skb(struct net_device *dev, unsigned int idx, unsigned int *frame_len_ptr); struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf); -- cgit v1.2.3 From c9e1d8ed304cc6106c3241add170193995953325 Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Tue, 14 Dec 2021 01:02:23 +0900 Subject: can: dev: replace can_priv::ctrlmode_static by can_get_static_ctrlmode() 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. Link: https://lore.kernel.org/all/20211213160226.56219-2-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol Signed-off-by: Marc Kleine-Budde --- 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(-) (limited to 'include/linux') diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c index 4845ae6456e1..c192f25f9695 100644 --- a/drivers/net/can/dev/dev.c +++ b/drivers/net/can/dev/dev.c @@ -296,6 +296,7 @@ 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) @@ -305,7 +306,7 @@ 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; @@ -314,7 +315,7 @@ 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, -- cgit v1.2.3 From 7d4a101c0bd3c6e5c6e45c705a54f7bc8f6c128d Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Tue, 14 Dec 2021 01:02:24 +0900 Subject: can: dev: add sanity check in can_set_static_ctrlmode() 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(). Link: https://lore.kernel.org/all/20211213160226.56219-3-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol Signed-off-by: Marc Kleine-Budde --- 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(-) (limited to 'include/linux') diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index ae2349420983..5b47cd867783 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -1456,7 +1456,7 @@ 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 */ @@ -1486,7 +1486,9 @@ 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; @@ -1496,7 +1498,9 @@ 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 d0e795f60338..82cc71d5ee10 100644 --- a/drivers/net/can/rcar/rcar_canfd.c +++ b/drivers/net/can/rcar/rcar_canfd.c @@ -1699,7 +1699,9 @@ 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) -- cgit v1.2.3 From 5fe1be81efd28bf2afcac218f23118dca6b1b648 Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Tue, 14 Dec 2021 01:02:25 +0900 Subject: can: dev: reorder struct can_priv members for better packing 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 */ | }; Link: https://lore.kernel.org/all/20211213160226.56219-4-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol Signed-off-by: Marc Kleine-Budde --- include/linux/can/dev.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux') 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]; -- cgit v1.2.3