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/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Holds initial configuration information for devices.
*
* Version: @(#)Space.c 1.0.7 08/12/93
*
* Authors: Ross Biro, <bir7@leland.Stanford.Edu>
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
* Donald J. Becker, <becker@scyld.com>
*
* Changelog:
* Arnaldo Carvalho de Melo <acme@conectiva.com.br> - 09/1999
* - fix sbni: s/device/net_device/
* Paul Gortmaker (06/98):
* - sort probes in a sane way, make sure all (safe) probes
* get run once & failed autoprobes don't autoprobe again.
*
* FIXME:
* Phase out placeholder dev entries put in the linked list
* here in favour of drivers using init_etherdev(NULL, ...)
* combined with a single find_all_devs() function (for 2.3)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/config.h>
#include <linux/netdevice.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/netlink.h>
#include <linux/divert.h>
#define NEXT_DEV NULL
/* A unified ethernet device probe. This is the easiest way to have every
ethernet adaptor have the name "eth[0123...]".
*/
extern int ne2_probe(struct net_device *dev);
extern int hp100_probe(struct net_device *dev);
extern int ultra_probe(struct net_device *dev);
extern int ultra32_probe(struct net_device *dev);
extern int ultramca_probe(struct net_device *dev);
extern int wd_probe(struct net_device *dev);
extern int el2_probe(struct net_device *dev);
extern int ne_probe(struct net_device *dev);
extern int hp_probe(struct net_device *dev);
extern int hp_plus_probe(struct net_device *dev);
extern int znet_probe(struct net_device *);
extern int express_probe(struct net_device *);
extern int eepro_probe(struct net_device *);
extern int el3_probe(struct net_device *);
extern int at1500_probe(struct net_device *);
extern int at1700_probe(struct net_device *);
extern int fmv18x_probe(struct net_device *);
extern int eth16i_probe(struct net_device *);
extern int depca_probe(struct net_device *);
extern int i82596_probe(struct net_device *);
extern int ewrk3_probe(struct net_device *);
extern int de4x5_probe(struct net_device *);
extern int el1_probe(struct net_device *);
extern int wavelan_probe(struct net_device *);
extern int arlan_probe(struct net_device *);
extern int el16_probe(struct net_device *);
extern int elmc_probe(struct net_device *);
extern int skmca_probe(struct net_device *);
extern int elplus_probe(struct net_device *);
extern int ac3200_probe(struct net_device *);
extern int es_probe(struct net_device *);
extern int lne390_probe(struct net_device *);
extern int ne3210_probe(struct net_device *);
extern int e2100_probe(struct net_device *);
extern int ni5010_probe(struct net_device *);
extern int ni52_probe(struct net_device *);
extern int ni65_probe(struct net_device *);
extern int sonic_probe(struct net_device *);
extern int SK_init(struct net_device *);
extern int seeq8005_probe(struct net_device *);
extern int smc_init( struct net_device * );
extern int sgiseeq_probe(struct net_device *);
extern int atarilance_probe(struct net_device *);
extern int sun3lance_probe(struct net_device *);
extern int apne_probe(struct net_device *);
extern int bionet_probe(struct net_device *);
extern int pamsnet_probe(struct net_device *);
extern int cs89x0_probe(struct net_device *dev);
extern int ethertap_probe(struct net_device *dev);
extern int hplance_probe(struct net_device *dev);
extern int bagetlance_probe(struct net_device *);
extern int mvme147lance_probe(struct net_device *dev);
extern int tc515_probe(struct net_device *dev);
extern int lance_probe(struct net_device *dev);
extern int mace68k_probe(struct net_device *dev);
extern int macsonic_probe(struct net_device *dev);
extern int mac8390_probe(struct net_device *dev);
extern int mac89x0_probe(struct net_device *dev);
extern int mc32_probe(struct net_device *dev);
/* Detachable devices ("pocket adaptors") */
extern int de600_probe(struct net_device *);
extern int de620_probe(struct net_device *);
/* FDDI adapters */
extern int skfp_probe(struct net_device *dev);
/* Fibre Channel adapters */
extern int iph5526_probe(struct net_device *dev);
/* SBNI adapters */
extern int sbni_probe(struct net_device *);
struct devprobe
{
int (*probe)(struct net_device *dev);
int status; /* non-zero if autoprobe has failed */
};
/*
* probe_list walks a list of probe functions and calls each so long
* as a non-zero ioaddr is given, or as long as it hasn't already failed
* to find a card in the past (as recorded by "status") when asked to
* autoprobe (i.e. a probe that fails to find a card when autoprobing
* will not be asked to autoprobe again). It exits when a card is found.
*/
static int __init probe_list(struct net_device *dev, struct devprobe *plist)
{
struct devprobe *p = plist;
unsigned long base_addr = dev->base_addr;
#ifdef CONFIG_NET_DIVERT
int ret;
#endif /* CONFIG_NET_DIVERT */
while (p->probe != NULL) {
if (base_addr && p->probe(dev) == 0) { /* probe given addr */
#ifdef CONFIG_NET_DIVERT
ret = alloc_divert_blk(dev);
if (ret)
return ret;
#endif /* CONFIG_NET_DIVERT */
return 0;
} else if (p->status == 0) { /* has autoprobe failed yet? */
p->status = p->probe(dev); /* no, try autoprobe */
if (p->status == 0) {
#ifdef CONFIG_NET_DIVERT
ret = alloc_divert_blk(dev);
if (ret)
return ret;
#endif /* CONFIG_NET_DIVERT */
return 0;
}
}
p++;
}
return -ENODEV;
}
/*
* This is a bit of an artificial separation as there are PCI drivers
* that also probe for EISA cards (in the PCI group) and there are ISA
* drivers that probe for EISA cards (in the ISA group). These are the
* EISA only driver probes, and also the legacy PCI probes
*/
static struct devprobe eisa_probes[] __initdata = {
#ifdef CONFIG_DE4X5 /* DEC DE425, DE434, DE435 adapters */
{de4x5_probe, 0},
#endif
#ifdef CONFIG_ULTRA32
{ultra32_probe, 0},
#endif
#ifdef CONFIG_AC3200
{ac3200_probe, 0},
#endif
#ifdef CONFIG_ES3210
{es_probe, 0},
#endif
#ifdef CONFIG_LNE390
{lne390_probe, 0},
#endif
#ifdef CONFIG_NE3210
{ne3210_probe, 0},
#endif
{NULL, 0},
};
static struct devprobe mca_probes[] __initdata = {
#ifdef CONFIG_ULTRAMCA
{ultramca_probe, 0},
#endif
#ifdef CONFIG_NE2_MCA
{ne2_probe, 0},
#endif
#ifdef CONFIG_ELMC /* 3c523 */
{elmc_probe, 0},
#endif
#ifdef CONFIG_ELMC_II /* 3c527 */
{mc32_probe, 0},
#endif
#ifdef CONFIG_SKMC /* SKnet Microchannel */
{skmca_probe, 0},
#endif
{NULL, 0},
};
/*
* ISA probes that touch addresses < 0x400 (including those that also
* look for EISA/PCI/MCA cards in addition to ISA cards).
*/
static struct devprobe isa_probes[] __initdata = {
#ifdef CONFIG_EL3 /* ISA, EISA, MCA 3c5x9 */
{el3_probe, 0},
#endif
#ifdef CONFIG_HP100 /* ISA, EISA & PCI */
{hp100_probe, 0},
#endif
#ifdef CONFIG_3C515
{tc515_probe, 0},
#endif
#ifdef CONFIG_ULTRA
{ultra_probe, 0},
#endif
#ifdef CONFIG_WD80x3
{wd_probe, 0},
#endif
#ifdef CONFIG_EL2 /* 3c503 */
{el2_probe, 0},
#endif
#ifdef CONFIG_HPLAN
{hp_probe, 0},
#endif
#ifdef CONFIG_HPLAN_PLUS
{hp_plus_probe, 0},
#endif
#ifdef CONFIG_E2100 /* Cabletron E21xx series. */
{e2100_probe, 0},
#endif
#ifdef CONFIG_NE2000 /* ISA (use ne2k-pci for PCI cards) */
{ne_probe, 0},
#endif
#ifdef CONFIG_LANCE /* ISA/VLB (use pcnet32 for PCI cards) */
{lance_probe, 0},
#endif
#ifdef CONFIG_SMC9194
{smc_init, 0},
#endif
#ifdef CONFIG_SEEQ8005
{seeq8005_probe, 0},
#endif
#ifdef CONFIG_AT1500
{at1500_probe, 0},
#endif
#ifdef CONFIG_CS89x0
{cs89x0_probe, 0},
#endif
#ifdef CONFIG_AT1700
{at1700_probe, 0},
#endif
#ifdef CONFIG_FMV18X /* Fujitsu FMV-181/182 */
{fmv18x_probe, 0},
#endif
#ifdef CONFIG_ETH16I
{eth16i_probe, 0}, /* ICL EtherTeam 16i/32 */
#endif
#ifdef CONFIG_ZNET /* Zenith Z-Note and some IBM Thinkpads. */
{znet_probe, 0},
#endif
#ifdef CONFIG_EEXPRESS /* Intel EtherExpress */
{express_probe, 0},
#endif
#ifdef CONFIG_EEXPRESS_PRO /* Intel EtherExpress Pro/10 */
{eepro_probe, 0},
#endif
#ifdef CONFIG_DEPCA /* DEC DEPCA */
{depca_probe, 0},
#endif
#ifdef CONFIG_EWRK3 /* DEC EtherWORKS 3 */
{ewrk3_probe, 0},
#endif
#if defined(CONFIG_APRICOT) || defined(CONFIG_MVME16x_NET) || defined(CONFIG_BVME6000_NET) /* Intel I82596 */
{i82596_probe, 0},
#endif
#ifdef CONFIG_EL1 /* 3c501 */
{el1_probe, 0},
#endif
#ifdef CONFIG_WAVELAN /* WaveLAN */
{wavelan_probe, 0},
#endif
#ifdef CONFIG_ARLAN /* Aironet */
{arlan_probe, 0},
#endif
#ifdef CONFIG_EL16 /* 3c507 */
{el16_probe, 0},
#endif
#ifdef CONFIG_ELPLUS /* 3c505 */
{elplus_probe, 0},
#endif
#ifdef CONFIG_SK_G16
{SK_init, 0},
#endif
#ifdef CONFIG_NI5010
{ni5010_probe, 0},
#endif
#ifdef CONFIG_NI52
{ni52_probe, 0},
#endif
#ifdef CONFIG_NI65
{ni65_probe, 0},
#endif
{NULL, 0},
};
static struct devprobe parport_probes[] __initdata = {
#ifdef CONFIG_DE600 /* D-Link DE-600 adapter */
{de600_probe, 0},
#endif
#ifdef CONFIG_DE620 /* D-Link DE-620 adapter */
{de620_probe, 0},
#endif
{NULL, 0},
};
static struct devprobe m68k_probes[] __initdata = {
#ifdef CONFIG_ATARILANCE /* Lance-based Atari ethernet boards */
{atarilance_probe, 0},
#endif
#ifdef CONFIG_SUN3LANCE /* sun3 onboard Lance chip */
{sun3lance_probe, 0},
#endif
#ifdef CONFIG_APNE /* A1200 PCMCIA NE2000 */
{apne_probe, 0},
#endif
#ifdef CONFIG_ATARI_BIONET /* Atari Bionet Ethernet board */
{bionet_probe, 0},
#endif
#ifdef CONFIG_ATARI_PAMSNET /* Atari PAMsNet Ethernet board */
{pamsnet_probe, 0},
#endif
#ifdef CONFIG_HPLANCE /* HP300 internal Ethernet */
{hplance_probe, 0},
#endif
#ifdef CONFIG_MVME147_NET /* MVME147 internal Ethernet */
{mvme147lance_probe, 0},
#endif
#ifdef CONFIG_MACMACE /* Mac 68k Quadra AV builtin Ethernet */
{mace68k_probe, 0},
#endif
#ifdef CONFIG_MACSONIC /* Mac SONIC-based Ethernet of all sorts */
{macsonic_probe, 0},
#endif
#ifdef CONFIG_MAC8390 /* NuBus NS8390-based cards */
{mac8390_probe, 0},
#endif
#ifdef CONFIG_MAC89x0
{mac89x0_probe, 0},
#endif
{NULL, 0},
};
static struct devprobe sgi_probes[] __initdata = {
#ifdef CONFIG_SGISEEQ
{sgiseeq_probe, 0},
#endif
{NULL, 0},
};
static struct devprobe mips_probes[] __initdata = {
#ifdef CONFIG_MIPS_JAZZ_SONIC
{sonic_probe, 0},
#endif
#ifdef CONFIG_BAGETLANCE /* Lance-based Baget ethernet boards */
{bagetlance_probe, 0},
#endif
{NULL, 0},
};
/*
* Unified ethernet device probe, segmented per architecture and
* per bus interface. This drives the legacy devices only for now.
*/
static int __init ethif_probe(struct net_device *dev)
{
unsigned long base_addr = dev->base_addr;
/*
* Backwards compatibility - historically an I/O base of 1 was
* used to indicate not to probe for this ethN interface
*/
if (base_addr == 1)
return 1; /* ENXIO */
/*
* The arch specific probes are 1st so that any on-board ethernet
* will be probed before other ISA/EISA/MCA/PCI bus cards.
*/
if (probe_list(dev, m68k_probes) == 0)
return 0;
if (probe_list(dev, mips_probes) == 0)
return 0;
if (probe_list(dev, sgi_probes) == 0)
return 0;
if (probe_list(dev, eisa_probes) == 0)
return 0;
if (probe_list(dev, mca_probes) == 0)
return 0;
/*
* Backwards compatibility - an I/O of 0xffe0 was used to indicate
* that we shouldn't do a bunch of potentially risky ISA probes
* for ethN (N>1). Since the widespread use of modules, *nobody*
* compiles a kernel with all the ISA drivers built in anymore,
* and so we should delete this check in linux 2.3 - Paul G.
*/
if (base_addr != 0xffe0 && probe_list(dev, isa_probes) == 0)
return 0;
if (probe_list(dev, parport_probes) == 0)
return 0;
return -ENODEV;
}
#ifdef CONFIG_FDDI
static int __init fddiif_probe(struct net_device *dev)
{
unsigned long base_addr = dev->base_addr;
if (base_addr == 1)
return 1; /* ENXIO */
if (1
#ifdef CONFIG_APFDDI
&& apfddi_init(dev)
#endif
#ifdef CONFIG_SKFP
&& skfp_probe(dev)
#endif
&& 1 ) {
return 1; /* -ENODEV or -EAGAIN would be more accurate. */
}
return 0;
}
#endif
#ifdef CONFIG_NET_FC
static int fcif_probe(struct net_device *dev)
{
if (dev->base_addr == -1)
return 1;
if (1
#ifdef CONFIG_IPHASE5526
&& iph5526_probe(dev)
#endif
&& 1 ) {
return 1; /* -ENODEV or -EAGAIN would be more accurate. */
}
return 0;
}
#endif /* CONFIG_NET_FC */
#ifdef CONFIG_ETHERTAP
static struct net_device tap0_dev = { "tap0", 0, 0, 0, 0, NETLINK_TAPBASE, 0, 0, 0, 0, NEXT_DEV, ethertap_probe, };
# undef NEXT_DEV
# define NEXT_DEV (&tap0_dev)
#endif
#ifdef CONFIG_SDLA
extern int sdla_init(struct net_device *);
static struct net_device sdla0_dev = { "sdla0", 0, 0, 0, 0, 0, 0, 0, 0, 0, NEXT_DEV, sdla_init, };
# undef NEXT_DEV
# define NEXT_DEV (&sdla0_dev)
#endif
#if defined(CONFIG_LTPC)
extern int ltpc_probe(struct net_device *);
static struct net_device dev_ltpc = {
"lt0",
0, 0, 0, 0,
0x0, 0,
0, 0, 0, NEXT_DEV, ltpc_probe };
# undef NEXT_DEV
# define NEXT_DEV (&dev_ltpc)
#endif /* LTPC */
#if defined(CONFIG_COPS)
extern int cops_probe(struct net_device *);
static struct net_device cops2_dev = { "lt2", 0, 0, 0, 0, 0x0, 0, 0, 0, 0, NEXT_DEV, cops_probe };
static struct net_device cops1_dev = { "lt1", 0, 0, 0, 0, 0x0, 0, 0, 0, 0, &cops2_dev, cops_probe };
static struct net_device cops0_dev = { "lt0", 0, 0, 0, 0, 0x0, 0, 0, 0, 0, &cops1_dev, cops_probe };
# undef NEXT_DEV
# define NEXT_DEV (&cops0_dev)
#endif /* COPS */
/* The first device defaults to I/O base '0', which means autoprobe. */
#ifndef ETH0_ADDR
# define ETH0_ADDR 0
#endif
#ifndef ETH0_IRQ
# define ETH0_IRQ 0
#endif
/* "eth0" defaults to autoprobe (== 0), other use a base of 0xffe0 (== -0x20),
which means "don't do ISA probes". Distributions don't ship kernels with
all ISA drivers compiled in anymore, so its probably no longer an issue. */
#define ETH_NOPROBE_ADDR 0xffe0
static struct net_device eth7_dev = {
"eth%d", 0,0,0,0,ETH_NOPROBE_ADDR /* I/O base*/, 0,0,0,0, NEXT_DEV, ethif_probe };
static struct net_device eth6_dev = {
"eth%d", 0,0,0,0,ETH_NOPROBE_ADDR /* I/O base*/, 0,0,0,0, ð7_dev, ethif_probe };
static struct net_device eth5_dev = {
"eth%d", 0,0,0,0,ETH_NOPROBE_ADDR /* I/O base*/, 0,0,0,0, ð6_dev, ethif_probe };
static struct net_device eth4_dev = {
"eth%d", 0,0,0,0,ETH_NOPROBE_ADDR /* I/O base*/, 0,0,0,0, ð5_dev, ethif_probe };
static struct net_device eth3_dev = {
"eth%d", 0,0,0,0,ETH_NOPROBE_ADDR /* I/O base*/, 0,0,0,0, ð4_dev, ethif_probe };
static struct net_device eth2_dev = {
"eth%d", 0,0,0,0,ETH_NOPROBE_ADDR /* I/O base*/, 0,0,0,0, ð3_dev, ethif_probe };
static struct net_device eth1_dev = {
"eth%d", 0,0,0,0,ETH_NOPROBE_ADDR /* I/O base*/, 0,0,0,0, ð2_dev, ethif_probe };
static struct net_device eth0_dev = {
"eth%d", 0, 0, 0, 0, ETH0_ADDR, ETH0_IRQ, 0, 0, 0, ð1_dev, ethif_probe };
# undef NEXT_DEV
# define NEXT_DEV (ð0_dev)
#ifdef CONFIG_TR
/* Token-ring device probe */
extern int ibmtr_probe(struct net_device *);
extern int smctr_probe(struct net_device *);
static int
trif_probe(struct net_device *dev)
{
if (1
#ifdef CONFIG_IBMTR
&& ibmtr_probe(dev)
#endif
#ifdef CONFIG_SMCTR
&& smctr_probe(dev)
#endif
&& 1 ) {
return 1; /* -ENODEV or -EAGAIN would be more accurate. */
}
return 0;
}
static struct net_device tr7_dev = {
"tr%d",0,0,0,0,0,0,0,0,0, NEXT_DEV, trif_probe };
static struct net_device tr6_dev = {
"tr%d",0,0,0,0,0,0,0,0,0, &tr7_dev, trif_probe };
static struct net_device tr5_dev = {
"tr%d",0,0,0,0,0,0,0,0,0, &tr6_dev, trif_probe };
static struct net_device tr4_dev = {
"tr%d",0,0,0,0,0,0,0,0,0, &tr5_dev, trif_probe };
static struct net_device tr3_dev = {
"tr%d",0,0,0,0,0,0,0,0,0, &tr4_dev, trif_probe };
static struct net_device tr2_dev = {
"tr%d",0,0,0,0,0,0,0,0,0, &tr3_dev, trif_probe };
static struct net_device tr1_dev = {
"tr%d",0,0,0,0,0,0,0,0,0, &tr2_dev, trif_probe };
static struct net_device tr0_dev = {
"tr%d",0,0,0,0,0,0,0,0,0, &tr1_dev, trif_probe };
# undef NEXT_DEV
# define NEXT_DEV (&tr0_dev)
#endif
#ifdef CONFIG_FDDI
static struct net_device fddi7_dev =
{"fddi7", 0, 0, 0, 0, 0, 0, 0, 0, 0, NEXT_DEV, fddiif_probe};
static struct net_device fddi6_dev =
{"fddi6", 0, 0, 0, 0, 0, 0, 0, 0, 0, &fddi7_dev, fddiif_probe};
static struct net_device fddi5_dev =
{"fddi5", 0, 0, 0, 0, 0, 0, 0, 0, 0, &fddi6_dev, fddiif_probe};
static struct net_device fddi4_dev =
{"fddi4", 0, 0, 0, 0, 0, 0, 0, 0, 0, &fddi5_dev, fddiif_probe};
static struct net_device fddi3_dev =
{"fddi3", 0, 0, 0, 0, 0, 0, 0, 0, 0, &fddi4_dev, fddiif_probe};
static struct net_device fddi2_dev =
{"fddi2", 0, 0, 0, 0, 0, 0, 0, 0, 0, &fddi3_dev, fddiif_probe};
static struct net_device fddi1_dev =
{"fddi1", 0, 0, 0, 0, 0, 0, 0, 0, 0, &fddi2_dev, fddiif_probe};
static struct net_device fddi0_dev =
{"fddi0", 0, 0, 0, 0, 0, 0, 0, 0, 0, &fddi1_dev, fddiif_probe};
#undef NEXT_DEV
#define NEXT_DEV (&fddi0_dev)
#endif
#ifdef CONFIG_NET_FC
static struct net_device fc1_dev = {
"fc1", 0, 0, 0, 0, 0, 0, 0, 0, 0, NEXT_DEV, fcif_probe};
static struct net_device fc0_dev = {
"fc0", 0, 0, 0, 0, 0, 0, 0, 0, 0, &fc1_dev, fcif_probe};
# undef NEXT_DEV
# define NEXT_DEV (&fc0_dev)
#endif
#ifdef CONFIG_SBNI
static struct net_device sbni7_dev =
{"sbni7", 0, 0, 0, 0, 0, 0, 0, 0, 0, NEXT_DEV, sbni_probe};
static struct net_device sbni6_dev =
{"sbni6", 0, 0, 0, 0, 0, 0, 0, 0, 0, &sbni7_dev, sbni_probe};
static struct net_device sbni5_dev =
{"sbni5", 0, 0, 0, 0, 0, 0, 0, 0, 0, &sbni6_dev, sbni_probe};
static struct net_device sbni4_dev =
{"sbni4", 0, 0, 0, 0, 0, 0, 0, 0, 0, &sbni5_dev, sbni_probe};
static struct net_device sbni3_dev =
{"sbni3", 0, 0, 0, 0, 0, 0, 0, 0, 0, &sbni4_dev, sbni_probe};
static struct net_device sbni2_dev =
{"sbni2", 0, 0, 0, 0, 0, 0, 0, 0, 0, &sbni3_dev, sbni_probe};
static struct net_device sbni1_dev =
{"sbni1", 0, 0, 0, 0, 0, 0, 0, 0, 0, &sbni2_dev, sbni_probe};
static struct net_device sbni0_dev =
{"sbni0", 0, 0, 0, 0, 0, 0, 0, 0, 0, &sbni1_dev, sbni_probe};
#undef NEXT_DEV
#define NEXT_DEV (&sbni0_dev)
#endif
/*
* The loopback device is global so it can be directly referenced
* by the network code. Also, it must be first on device list.
*/
extern int loopback_init(struct net_device *dev);
struct net_device loopback_dev =
{"lo", 0, 0, 0, 0, 0, 0, 0, 0, 0, NEXT_DEV, loopback_init};
/*
* The @dev_base list is protected by @dev_base_lock and the rtln
* semaphore.
*
* Pure readers hold dev_base_lock for reading.
*
* Writers must hold the rtnl semaphore while they loop through the
* dev_base list, and hold dev_base_lock for writing when they do the
* actual updates. This allows pure readers to access the list even
* while a writer is preparing to update it.
*
* To put it another way, dev_base_lock is held for writing only to
* protect against pure readers; the rtnl semaphore provides the
* protection against other writers.
*
* See, for example usages, register_netdevice() and
* unregister_netdevice(), which must be called with the rtnl
* semaphore held.
*/
struct net_device *dev_base = &loopback_dev;
rwlock_t dev_base_lock = RW_LOCK_UNLOCKED;
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