iflib: mark irq allocation name parameter as constant

[jacob.e.keller_intel.com]

Summary

The *name parameter passed to iflib_irq_alloc_generic and
iflib_softirq_alloc_generic is never modified. Many places in code pass
string literals and thus should not be modified.

Mark the *name parameter as a const char * instead, so that we enforce
that the name is not modified before passing to bus_describe_intr()

[kmacy]

LGTM

[shurd]

Are there some bits missing from the review?

/usr/home/shurd/src/fbsd/sys/net/iflib.c:5308:92: error: passing 'const char *' to parameter of type 'char *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
err = iflib_irq_set_affinity(ctx, rman_get_start(irq->ii_res), type, qid, gtask, tqg, q, name);
^~~~
/usr/home/shurd/src/fbsd/sys/net/iflib.c:5215:72: note: passing argument to parameter 'name' here
struct grouptask *gtask, struct taskqgroup *tqg, void *uniq, char *name)
^
/usr/home/shurd/src/fbsd/sys/net/iflib.c:5356:72: error: passing 'const char *' to parameter of type 'char *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
err = iflib_irq_set_affinity(ctx, irq_num, type, qid, gtask, tqg, q, name);
^~~~
/usr/home/shurd/src/fbsd/sys/net/iflib.c:5215:72: note: passing argument to parameter 'name' here
struct grouptask *gtask, struct taskqgroup *tqg, void *uniq, char *name)
^
/usr/home/shurd/src/fbsd/sys/net/iflib.c:5376:1: error: conflicting types for 'iflib_legacy_setup'
iflib_legacy_setup(if_ctx_t ctx, driver_filter_t filter, void *filter_arg, int *rid, const char *name)
^
/usr/home/shurd/src/fbsd/sys/net/iflib.c:723:12: note: previous declaration is here
static int iflib_legacy_setup(if_ctx_t ctx, driver_filter_t filter, void *filterarg, int *rid, char *str);
^

[jacob.e.keller_intel.com]

Hmmm... I think there were. I'll double check this later today and see what I missed. I have a separate system for sending the reviews because my test system doesn't have direct access, I probably just forgot a few lines..

[jacob.e.keller_intel.com]

Looks like this involves a bit more cleanup to the taskqgroup code (since ultimately the name gets passed there). due to the scope I think I'll split it into two commits.

[jacob.e.keller_intel.com]

• taskqgroup: make tqg_name a constant
• taskqgroup: mark name paramter of taskqgroup_attach as const
• iflib: mark irq allocation name parameter as constant

[shurd]

Looks good.