Date: Wed, 28 Sep 2011 20:12:56 -0400 (EDT) From: Benjamin Kaduk <kaduk@MIT.EDU> To: Liu Wang <liuw@supermicro.com> Cc: "freebsd-doc@freebsd.org" <freebsd-doc@freebsd.org> Subject: Re: Are "mypci_driver" typos for "mypci_cdevsw" in "FreeBSD Architecture Handbook" , page 159, section 11.1.1, line 9 & 10 ? Message-ID: <alpine.GSO.1.10.1109282006390.882@multics.mit.edu> In-Reply-To: <09F85D53A2F0C547BF5E05E214DB880A23C81FCB3C@MAIL5.supermicro.com> References: <09F85D53A2F0C547BF5E05E214DB880A23C81FCB3C@MAIL5.supermicro.com>
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On Wed, 28 Sep 2011, Liu Wang wrote:
> Are "mypci_driver" typos for "mypci_cdevsw" in "FreeBSD Architecture
> Handbook" , page 159, section 11.1.1, line 9 & 10 ?
The architecture handbook has not been well-loved over the past few years,
and is not exactly authoritative on very much at the moment.
A look at other uses of the DEFINE_CLASS_0 and DRIVER_MODULE macros (e.g.
dev/pci/pci_pci.c) and consulting fxr.watson.org seems to indicate that
these arguments should not be existing symbols:
103 DEFINE_CLASS_0(pcib, pcib_driver, pcib_methods, sizeof(struct pcib_softc));
104 DRIVER_MODULE(pcib, pci, pcib_driver, pcib_devclass, 0, 0);
FXR does not see "pcib_driver" as a symbol.
Indeed, looking at the macro implementation reveals that this argument is
used to define a new symbol as part of the macro expansion:
#define DEFINE_CLASS_0(name, classvar, methods, size) \
\
struct kobj_class classvar = { \
#name, methods, size, NULL \
}
#define DRIVER_MODULE(name, busname, driver, devclass, evh, arg) \
EARLY_DRIVER_MODULE(name, busname, driver, devclass, evh, arg, \
BUS_PASS_DEFAULT)
#define EARLY_DRIVER_MODULE(name, busname, driver, devclass, evh, arg, pass) \
\
static struct driver_module_data name##_##busname##_driver_mod = { \
evh, arg, \
#busname, \
(kobj_class_t) &driver, \
&devclass, \
pass \
}; \
\
static moduledata_t name##_##busname##_mod = { \
#busname "/" #name, \
driver_module_handler, \
&name##_##busname##_driver_mod \
}; \
DECLARE_MODULE(name##_##busname, name##_##busname##_mod, \
SI_SUB_DRIVERS, SI_ORDER_MIDDLE)
So, given that mypci_cdevsw is already declared, the answer to your
question is "no".
-Ben Kaduk
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