diff options
| author | Vladimir Oltean | 2021-10-12 14:40:40 +0300 |
|---|---|---|
| committer | Jakub Kicinski | 2021-10-12 17:35:18 -0700 |
| commit | deab6b1cd9789bb9bd466d5e76aecb8b336259b4 (patch) | |
| tree | fe4b45eb3ba2747af1991fb370ec5a79b49b0dc6 /include/linux | |
| parent | ebb4c6a990f786d7e0e4618a0d3766cd660125d8 (diff) | |
net: dsa: tag_ocelot: break circular dependency with ocelot switch lib driver
As explained here:
https://lore.kernel.org/netdev/20210908220834.d7gmtnwrorhharna@skbuf/
DSA tagging protocol drivers cannot depend on symbols exported by switch
drivers, because this creates a circular dependency that breaks module
autoloading.
The tag_ocelot.c file depends on the ocelot_ptp_rew_op() function
exported by the common ocelot switch lib. This function looks at
OCELOT_SKB_CB(skb) and computes how to populate the REW_OP field of the
DSA tag, for PTP timestamping (the command: one-step/two-step, and the
TX timestamp identifier).
None of that requires deep insight into the driver, it is quite
stateless, as it only depends upon the skb->cb. So let's make it a
static inline function and put it in include/linux/dsa/ocelot.h, a
file that despite its name is used by the ocelot switch driver for
populating the injection header too - since commit 40d3f295b5fe ("net:
mscc: ocelot: use common tag parsing code with DSA").
With that function declared as static inline, its body is expanded
inside each call site, so the dependency is broken and the DSA tagger
can be built without the switch library, upon which the felix driver
depends.
Fixes: 39e5308b3250 ("net: mscc: ocelot: support PTP Sync one-step timestamping")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/dsa/ocelot.h | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/include/linux/dsa/ocelot.h b/include/linux/dsa/ocelot.h index 435777a0073c..50641a7529ad 100644 --- a/include/linux/dsa/ocelot.h +++ b/include/linux/dsa/ocelot.h @@ -6,6 +6,26 @@ #define _NET_DSA_TAG_OCELOT_H #include <linux/packing.h> +#include <linux/skbuff.h> + +struct ocelot_skb_cb { + struct sk_buff *clone; + unsigned int ptp_class; /* valid only for clones */ + u8 ptp_cmd; + u8 ts_id; +}; + +#define OCELOT_SKB_CB(skb) \ + ((struct ocelot_skb_cb *)((skb)->cb)) + +#define IFH_TAG_TYPE_C 0 +#define IFH_TAG_TYPE_S 1 + +#define IFH_REW_OP_NOOP 0x0 +#define IFH_REW_OP_DSCP 0x1 +#define IFH_REW_OP_ONE_STEP_PTP 0x2 +#define IFH_REW_OP_TWO_STEP_PTP 0x3 +#define IFH_REW_OP_ORIGIN_PTP 0x5 #define OCELOT_TAG_LEN 16 #define OCELOT_SHORT_PREFIX_LEN 4 @@ -215,4 +235,21 @@ static inline void ocelot_ifh_set_vid(void *injection, u64 vid) packing(injection, &vid, 11, 0, OCELOT_TAG_LEN, PACK, 0); } +/* Determine the PTP REW_OP to use for injecting the given skb */ +static inline u32 ocelot_ptp_rew_op(struct sk_buff *skb) +{ + struct sk_buff *clone = OCELOT_SKB_CB(skb)->clone; + u8 ptp_cmd = OCELOT_SKB_CB(skb)->ptp_cmd; + u32 rew_op = 0; + + if (ptp_cmd == IFH_REW_OP_TWO_STEP_PTP && clone) { + rew_op = ptp_cmd; + rew_op |= OCELOT_SKB_CB(clone)->ts_id << 3; + } else if (ptp_cmd == IFH_REW_OP_ORIGIN_PTP) { + rew_op = ptp_cmd; + } + + return rew_op; +} + #endif |