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linux-stable/net/8021q/vlan.h
Alexey Dobriyan c7d03a00b5 netns: make struct pernet_operations::id unsigned int 
Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

	void f(long *p, int i)
	{
		g(p[i]);
	}

  roughly translates to

	movsx	rsi, esi
	mov	rdi, [rsi+...]
	call 	g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

	static inline void *net_generic(const struct net *net, int id)
	{
		...
		ptr = ng->ptr[id - 1];
		...
	}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
	function                                     old     new   delta
	nfsd4_lock                                  3886    3959     +73
	tipc_link_build_proto_msg                   1096    1140     +44
	mac80211_hwsim_new_radio                    2776    2808     +32
	tipc_mon_rcv                                1032    1058     +26
	svcauth_gss_legacy_init                     1413    1429     +16
	tipc_bcbase_select_primary                   379     392     +13
	nfsd4_exchange_id                           1247    1260     +13
	nfsd4_setclientid_confirm                    782     793     +11
		...
	put_client_renew_locked                      494     480     -14
	ip_set_sockfn_get                            730     716     -14
	geneve_sock_add                              829     813     -16
	nfsd4_sequence_done                          721     703     -18
	nlmclnt_lookup_host                          708     686     -22
	nfsd4_lockt                                 1085    1063     -22
	nfs_get_client                              1077    1050     -27
	tcf_bpf_init                                1106    1076     -30
	nfsd4_encode_fattr                          5997    5930     -67
	Total: Before=154856051, After=154854321, chg -0.00%

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-18 10:59:15 -05:00

175 lines
5.4 KiB
C
Raw Blame History

#ifndef __BEN_VLAN_802_1Q_INC__
#define __BEN_VLAN_802_1Q_INC__
#include <linux/if_vlan.h>
#include <linux/u64_stats_sync.h>
#include <linux/list.h>
/* if this changes, algorithm will have to be reworked because this
* depends on completely exhausting the VLAN identifier space. Thus
* it gives constant time look-up, but in many cases it wastes memory.
*/
#define VLAN_GROUP_ARRAY_SPLIT_PARTS 8
#define VLAN_GROUP_ARRAY_PART_LEN (VLAN_N_VID/VLAN_GROUP_ARRAY_SPLIT_PARTS)
enum vlan_protos {
VLAN_PROTO_8021Q = 0,
VLAN_PROTO_8021AD,
VLAN_PROTO_NUM,
};
struct vlan_group {
unsigned int nr_vlan_devs;
struct hlist_node hlist; /* linked list */
struct net_device **vlan_devices_arrays[VLAN_PROTO_NUM]
[VLAN_GROUP_ARRAY_SPLIT_PARTS];
};
struct vlan_info {
struct net_device *real_dev; /* The ethernet(like) device
* the vlan is attached to.
*/
struct vlan_group grp;
struct list_head vid_list;
unsigned int nr_vids;
struct rcu_head rcu;
};
static inline unsigned int vlan_proto_idx(__be16 proto)
{
switch (proto) {
case htons(ETH_P_8021Q):
return VLAN_PROTO_8021Q;
case htons(ETH_P_8021AD):
return VLAN_PROTO_8021AD;
default:
BUG();
return 0;
}
}
static inline struct net_device *__vlan_group_get_device(struct vlan_group *vg,
unsigned int pidx,
u16 vlan_id)
{
struct net_device **array;
array = vg->vlan_devices_arrays[pidx]
[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
return array ? array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] : NULL;
}
static inline struct net_device *vlan_group_get_device(struct vlan_group *vg,
__be16 vlan_proto,
u16 vlan_id)
{
return __vlan_group_get_device(vg, vlan_proto_idx(vlan_proto), vlan_id);
}
static inline void vlan_group_set_device(struct vlan_group *vg,
__be16 vlan_proto, u16 vlan_id,
struct net_device *dev)
{
struct net_device **array;
if (!vg)
return;
array = vg->vlan_devices_arrays[vlan_proto_idx(vlan_proto)]
[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
}
/* Must be invoked with rcu_read_lock or with RTNL. */
static inline struct net_device *vlan_find_dev(struct net_device *real_dev,
__be16 vlan_proto, u16 vlan_id)
{
struct vlan_info *vlan_info = rcu_dereference_rtnl(real_dev->vlan_info);
if (vlan_info)
return vlan_group_get_device(&vlan_info->grp,
vlan_proto, vlan_id);
return NULL;
}
#define vlan_group_for_each_dev(grp, i, dev) \
for ((i) = 0; i < VLAN_PROTO_NUM * VLAN_N_VID; i++) \
if (((dev) = __vlan_group_get_device((grp), (i) / VLAN_N_VID, \
(i) % VLAN_N_VID)))
/* found in vlan_dev.c */
void vlan_dev_set_ingress_priority(const struct net_device *dev,
u32 skb_prio, u16 vlan_prio);
int vlan_dev_set_egress_priority(const struct net_device *dev,
u32 skb_prio, u16 vlan_prio);
int vlan_dev_change_flags(const struct net_device *dev, u32 flag, u32 mask);
void vlan_dev_get_realdev_name(const struct net_device *dev, char *result);
int vlan_check_real_dev(struct net_device *real_dev,
__be16 protocol, u16 vlan_id);
void vlan_setup(struct net_device *dev);
int register_vlan_dev(struct net_device *dev);
void unregister_vlan_dev(struct net_device *dev, struct list_head *head);
bool vlan_dev_inherit_address(struct net_device *dev,
struct net_device *real_dev);
static inline u32 vlan_get_ingress_priority(struct net_device *dev,
u16 vlan_tci)
{
struct vlan_dev_priv *vip = vlan_dev_priv(dev);
return vip->ingress_priority_map[(vlan_tci >> VLAN_PRIO_SHIFT) & 0x7];
}
#ifdef CONFIG_VLAN_8021Q_GVRP
int vlan_gvrp_request_join(const struct net_device *dev);
void vlan_gvrp_request_leave(const struct net_device *dev);
int vlan_gvrp_init_applicant(struct net_device *dev);
void vlan_gvrp_uninit_applicant(struct net_device *dev);
int vlan_gvrp_init(void);
void vlan_gvrp_uninit(void);
#else
static inline int vlan_gvrp_request_join(const struct net_device *dev) { return 0; }
static inline void vlan_gvrp_request_leave(const struct net_device *dev) {}
static inline int vlan_gvrp_init_applicant(struct net_device *dev) { return 0; }
static inline void vlan_gvrp_uninit_applicant(struct net_device *dev) {}
static inline int vlan_gvrp_init(void) { return 0; }
static inline void vlan_gvrp_uninit(void) {}
#endif
#ifdef CONFIG_VLAN_8021Q_MVRP
int vlan_mvrp_request_join(const struct net_device *dev);
void vlan_mvrp_request_leave(const struct net_device *dev);
int vlan_mvrp_init_applicant(struct net_device *dev);
void vlan_mvrp_uninit_applicant(struct net_device *dev);
int vlan_mvrp_init(void);
void vlan_mvrp_uninit(void);
#else
static inline int vlan_mvrp_request_join(const struct net_device *dev) { return 0; }
static inline void vlan_mvrp_request_leave(const struct net_device *dev) {}
static inline int vlan_mvrp_init_applicant(struct net_device *dev) { return 0; }
static inline void vlan_mvrp_uninit_applicant(struct net_device *dev) {}
static inline int vlan_mvrp_init(void) { return 0; }
static inline void vlan_mvrp_uninit(void) {}
#endif
extern const char vlan_fullname[];
extern const char vlan_version[];
int vlan_netlink_init(void);
void vlan_netlink_fini(void);
extern struct rtnl_link_ops vlan_link_ops;
extern unsigned int vlan_net_id;
struct proc_dir_entry;
struct vlan_net {
/* /proc/net/vlan */
struct proc_dir_entry *proc_vlan_dir;
/* /proc/net/vlan/config */
struct proc_dir_entry *proc_vlan_conf;
/* Determines interface naming scheme. */
unsigned short name_type;
};
#endif /* !(__BEN_VLAN_802_1Q_INC__) */
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