Commit f073cc8f authored by Cliff Wickman's avatar Cliff Wickman Committed by Ingo Molnar
Browse files

x86, UV: Clean up uv_tlb.c 



SGI UV's uv_tlb.c driver has become rather hard to read, with overly large
functions, non-standard coding style and (way) too long variable, constant
and function names and non-obvious code flow sequences.

This patch improves the readability and maintainability of the driver
significantly, by doing the following strict code cleanups with no side
effects:

 - Split long functions into shorter logical functions.

 - Shortened some variable and structure member names.

 - Added special functions for reads and writes of MMR regs with
   very long names.

 - Added the 'tunables' table to shortened tunables_write().

 - Added the 'stat_description' table to shorten uv_ptc_proc_write().

 - Pass fewer 'stat' arguments where it can be derived from the 'bcp'
   argument.

 - Function definitions consistent on one line, and inline in few (short) cases.

 - Moved some small structures and an atomic inline function to the header file.

 - Moved some local variables to the blocks where they are used.

 - Updated the copyright date.

 - Shortened uv_write_global_mmr64() etc. using some aliasing; no
   line breaks. Renamed many uv_.. functions that are not exported.

 - Aligned structure fields.
    [ note that not all structures are aligned the same way though; I'd like
      to keep the extensive commenting in some of them. ]

 - Shortened some long structure names.

 - Standard pass/fail exit from init_per_cpu()

 - Vertical alignment for mass initializations.

 - More separation between blocks of code.

Tested on a 16-processor Altix UV.

Signed-off-by: default avatarCliff Wickman <cpw@sgi.com>
Cc: penberg@kernel.org
Link: http://lkml.kernel.org/r/E1QOw12-0004MN-Lp@eag09.americas.sgi.com


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 2a919596

arch/x86/include/asm/uv/uv_bau.h

+351 −203
Original line number Diff line number Diff line
@@ -5,7 +5,7 @@ 
 *

 * SGI UV Broadcast Assist Unit definitions

 *

 * Copyright (C) 2008 Silicon Graphics, Inc. All rights reserved.

 * Copyright (C) 2008-2011 Silicon Graphics, Inc. All rights reserved.

 */



#ifndef _ASM_X86_UV_UV_BAU_H
@@ -35,9 +35,9 @@ 


#define MAX_CPUS_PER_UVHUB		64

#define MAX_CPUS_PER_SOCKET		32

#define UV_ADP_SIZE			64 /* hardware-provided max. */

#define UV_CPUS_PER_ACT_STATUS		32 /* hardware-provided max. */

#define UV_ITEMS_PER_DESCRIPTOR		8

#define ADP_SZ				64 /* hardware-provided max. */

#define UV_CPUS_PER_AS			32 /* hardware-provided max. */

#define ITEMS_PER_DESC			8

/* the 'throttle' to prevent the hardware stay-busy bug */

#define MAX_BAU_CONCURRENT		3

#define UV_ACT_STATUS_MASK		0x3
@@ -48,7 +48,7 @@ 
#define UV2_NET_ENDPOINT_INTD		0x28

#define UV_NET_ENDPOINT_INTD		(is_uv1_hub() ?			\

			UV1_NET_ENDPOINT_INTD : UV2_NET_ENDPOINT_INTD)

#define UV_DESC_BASE_PNODE_SHIFT	49

#define UV_DESC_PSHIFT			49

#define UV_PAYLOADQ_PNODE_SHIFT		49

#define UV_PTC_BASENAME			"sgi_uv/ptc_statistics"

#define UV_BAU_BASENAME			"sgi_uv/bau_tunables"
@@ -56,7 +56,8 @@ 
#define UV_BAU_TUNABLES_FILE		"bau_tunables"

#define WHITESPACE			" \t\n"

#define uv_physnodeaddr(x)		((__pa((unsigned long)(x)) & uv_mmask))



#define cpubit_isset(cpu, bau_local_cpumask) \

	test_bit((cpu), (bau_local_cpumask).bits)



/* [19:16] SOFT_ACK timeout period  19: 1 is urgency 7  17:16 1 is multiplier */

/*
@@ -84,13 +85,25 @@ 
#define BAU_TRANS_SHIFT			40

#define BAU_TRANS_MASK			0x3f



/*

 * shorten some awkward names

 */

#define AS_PUSH_SHIFT UVH_LB_BAU_SB_ACTIVATION_CONTROL_PUSH_SHFT

#define SOFTACK_MSHIFT UVH_LB_BAU_MISC_CONTROL_ENABLE_INTD_SOFT_ACK_MODE_SHFT

#define SOFTACK_PSHIFT UVH_LB_BAU_MISC_CONTROL_INTD_SOFT_ACK_TIMEOUT_PERIOD_SHFT

#define SOFTACK_TIMEOUT_PERIOD UV_INTD_SOFT_ACK_TIMEOUT_PERIOD

#define write_gmmr	uv_write_global_mmr64

#define write_lmmr	uv_write_local_mmr

#define read_lmmr	uv_read_local_mmr

#define read_gmmr	uv_read_global_mmr64



/*

 * bits in UVH_LB_BAU_SB_ACTIVATION_STATUS_0/1

 */

#define DESC_STATUS_IDLE		0

#define DESC_STATUS_ACTIVE		1

#define DESC_STATUS_DESTINATION_TIMEOUT	2

#define DESC_STATUS_SOURCE_TIMEOUT	3

#define DS_IDLE				0

#define DS_ACTIVE			1

#define DS_DESTINATION_TIMEOUT		2

#define DS_SOURCE_TIMEOUT		3

/*

 * bits put together from HRP_LB_BAU_SB_ACTIVATION_STATUS_0/1/2

 * values 1 and 5 will not occur
@@ -149,9 +162,16 @@ 
/*

 * tuning the action when the numalink network is extremely delayed

 */

#define CONGESTED_RESPONSE_US 1000 /* 'long' response time, in microseconds */

#define CONGESTED_REPS 10 /* long delays averaged over this many broadcasts */

#define CONGESTED_PERIOD 30 /* time for the bau to be disabled, in seconds */

#define CONGESTED_RESPONSE_US		1000	/* 'long' response time, in

						   microseconds */

#define CONGESTED_REPS			10	/* long delays averaged over

						   this many broadcasts */

#define CONGESTED_PERIOD		30	/* time for the bau to be

						   disabled, in seconds */

/* see msg_type: */

#define MSG_NOOP			0

#define MSG_REGULAR			1

#define MSG_RETRY			2



/*

 * Distribution: 32 bytes (256 bits) (bytes 0-0x1f of descriptor)
@@ -163,7 +183,7 @@ 
 * 'base_dest_nasid' field of the header corresponds to the

 * destination nodeID associated with that specified bit.

 */

struct bau_target_uvhubmask {

struct bau_targ_hubmask {

	unsigned long		bits[BITS_TO_LONGS(UV_DISTRIBUTION_SIZE)];

};
@@ -194,8 +214,8 @@ struct bau_local_cpumask { 
 * The payload is software-defined for INTD transactions

 */

struct bau_msg_payload {

	unsigned long address;		/* signifies a page or all TLB's

						of the cpu */

	unsigned long	address;		/* signifies a page or all

						   TLB's of the cpu */

	/* 64 bits */

	unsigned short	sending_cpu;		/* filled in by sender */

	/* 16 bits */
@@ -212,8 +232,8 @@ struct bau_msg_payload { 
struct bau_msg_header {

	unsigned int	dest_subnodeid:6;	/* must be 0x10, for the LB */

	/* bits 5:0 */

	unsigned int base_dest_nasid:15; /* nasid of the */

	/* bits 20:6 */			  /* first bit in uvhub map */

	unsigned int	base_dest_nasid:15;	/* nasid of the first bit */

	/* bits 20:6 */				/* in uvhub map */

	unsigned int	command:8;		/* message type */

	/* bits 28:21 */

	/* 0x38: SN3net EndPoint Message */
@@ -225,20 +245,24 @@ struct bau_msg_header { 
	/* Suppl_A is 56-41 */

	unsigned int	sequence:16;		/* message sequence number */

	/* bits 56:41 */			/* becomes bytes 16-17 of msg */

				/* Address field (96:57) is never used as an

				   address (these are address bits 42:3) */

						/* Address field (96:57) is

						   never used as an address

						   (these are address bits

						   42:3) */



	unsigned int	rsvd_3:1;		/* must be zero */

	/* bit 57 */

	/* address bits 27:4 are payload */

	/* these next 24  (58-81) bits become bytes 12-14 of msg */



	/* bits 65:58 land in byte 12 */

	unsigned int replied_to:1;/* sent as 0 by the source to byte 12 */

	unsigned int	replied_to:1;		/* sent as 0 by the source to

						   byte 12 */

	/* bit 58 */

	unsigned int msg_type:3; /* software type of the message*/

	unsigned int	msg_type:3;		/* software type of the

						   message */

	/* bits 61:59 */

	unsigned int canceled:1; /* message canceled, resource to be freed*/

	unsigned int	canceled:1;		/* message canceled, resource

						   is to be freed*/

	/* bit 62 */

	unsigned int	payload_1a:1;		/* not currently used */

	/* bit 63 */
@@ -259,39 +283,38 @@ struct bau_msg_header { 


	unsigned int	rsvd_4:7;		/* must be zero */

	/* bits 88:82 */

	unsigned int sw_ack_flag:1;/* software acknowledge flag */

	unsigned int	swack_flag:1;		/* software acknowledge flag */

	/* bit 89 */

				/* INTD trasactions at destination are to

				   wait for software acknowledge */

						/* INTD trasactions at

						   destination are to wait for

						   software acknowledge */

	unsigned int	rsvd_5:6;		/* must be zero */

	/* bits 95:90 */

	unsigned int	rsvd_6:5;		/* must be zero */

	/* bits 100:96 */

	unsigned int int_both:1;/* if 1, interrupt both sockets on the uvhub */

	unsigned int	int_both:1;		/* if 1, interrupt both sockets

						   on the uvhub */

	/* bit 101*/

	unsigned int	fairness:3;		/* usually zero */

	/* bits 104:102 */

	unsigned int multilevel:1;	/* multi-level multicast format */

	unsigned int	multilevel:1;		/* multi-level multicast

						   format */

	/* bit 105 */

	/* 0 for TLB: endpoint multi-unicast messages */

	unsigned int chaining:1;/* next descriptor is part of this activation*/

	unsigned int	chaining:1;		/* next descriptor is part of

						   this activation*/

	/* bit 106 */

	unsigned int	rsvd_7:21;		/* must be zero */

	/* bits 127:107 */

};



/* see msg_type: */

#define MSG_NOOP 0

#define MSG_REGULAR 1

#define MSG_RETRY 2



/*

 * The activation descriptor:

 * The format of the message to send, plus all accompanying control

 * Should be 64 bytes

 */

struct bau_desc {

	struct bau_target_uvhubmask distribution;

	struct bau_targ_hubmask	distribution;

	/*

	 * message template, consisting of header and payload:

	 */
@@ -315,55 +338,47 @@ struct bau_desc { 
 * are 32 bytes (2 micropackets) (256 bits) in length, but contain only 17

 * bytes of usable data, including the sw ack vector in byte 15 (bits 127:120)

 * (12 bytes come from bau_msg_payload, 3 from payload_1, 2 from

 *  sw_ack_vector and payload_2)

 *  swack_vec and payload_2)

 * "Enabling Software Acknowledgment mode (see Section 4.3.3 Software

 *  Acknowledge Processing) also selects 32 byte (17 bytes usable) payload

 *  operation."

 */

struct bau_payload_queue_entry {

struct bau_pq_entry {

	unsigned long	address;	/* signifies a page or all TLB's

					   of the cpu */

	/* 64 bits, bytes 0-7 */



	unsigned short	sending_cpu;	/* cpu that sent the message */

	/* 16 bits, bytes 8-9 */



	unsigned short	acknowledge_count; /* filled in by destination */

	/* 16 bits, bytes 10-11 */



	/* these next 3 bytes come from bits 58-81 of the message header */

	unsigned short	replied_to:1;	/* sent as 0 by the source */

	unsigned short	msg_type:3;	/* software message type */

	unsigned short	canceled:1;	/* sent as 0 by the source */

	unsigned short	unused1:3;	/* not currently using */

	/* byte 12 */



	unsigned char	unused2a;	/* not currently using */

	/* byte 13 */

	unsigned char	unused2;	/* not currently using */

	/* byte 14 */



	unsigned char sw_ack_vector;	/* filled in by the hardware */

	unsigned char	swack_vec;	/* filled in by the hardware */

	/* byte 15 (bits 127:120) */



	unsigned short	sequence;	/* message sequence number */

	/* bytes 16-17 */

	unsigned char	unused4[2];	/* not currently using bytes 18-19 */

	/* bytes 18-19 */



	int		number_of_cpus;	/* filled in at destination */

	/* 32 bits, bytes 20-23 (aligned) */



	unsigned char	unused5[8];	/* not using */

	/* bytes 24-31 */

};



struct msg_desc {

	struct bau_payload_queue_entry *msg;

	struct bau_pq_entry	*msg;

	int			msg_slot;

	int sw_ack_slot;

	struct bau_payload_queue_entry *va_queue_first;

	struct bau_payload_queue_entry *va_queue_last;

	int			swack_slot;

	struct bau_pq_entry	*queue_first;

	struct bau_pq_entry	*queue_last;

};



struct reset_args {
@@ -375,57 +390,101 @@ struct reset_args { 
 */

struct ptc_stats {

	/* sender statistics */

	unsigned long s_giveup; /* number of fall backs to IPI-style flushes */

	unsigned long s_requestor; /* number of shootdown requests */

	unsigned long	s_giveup;		/* number of fall backs to

						   IPI-style flushes */

	unsigned long	s_requestor;		/* number of shootdown

						   requests */

	unsigned long	s_stimeout;		/* source side timeouts */

	unsigned long	s_dtimeout;		/* destination side timeouts */

	unsigned long	s_time;			/* time spent in sending side */

	unsigned long	s_retriesok;		/* successful retries */

	unsigned long s_ntargcpu; /* total number of cpu's targeted */

	unsigned long s_ntargself; /* times the sending cpu was targeted */

	unsigned long s_ntarglocals; /* targets of cpus on the local blade */

	unsigned long s_ntargremotes; /* targets of cpus on remote blades */

	unsigned long	s_ntargcpu;		/* total number of cpu's

						   targeted */

	unsigned long	s_ntargself;		/* times the sending cpu was

						   targeted */

	unsigned long	s_ntarglocals;		/* targets of cpus on the local

						   blade */

	unsigned long	s_ntargremotes;		/* targets of cpus on remote

						   blades */

	unsigned long	s_ntarglocaluvhub;	/* targets of the local hub */

	unsigned long	s_ntargremoteuvhub;	/* remotes hubs targeted */

	unsigned long s_ntarguvhub; /* total number of uvhubs targeted */

	unsigned long s_ntarguvhub16; /* number of times target hubs >= 16*/

	unsigned long s_ntarguvhub8; /* number of times target hubs >= 8 */

	unsigned long s_ntarguvhub4; /* number of times target hubs >= 4 */

	unsigned long s_ntarguvhub2; /* number of times target hubs >= 2 */

	unsigned long s_ntarguvhub1; /* number of times target hubs == 1 */

	unsigned long s_resets_plug; /* ipi-style resets from plug state */

	unsigned long s_resets_timeout; /* ipi-style resets from timeouts */

	unsigned long s_busy; /* status stayed busy past s/w timer */

	unsigned long	s_ntarguvhub;		/* total number of uvhubs

						   targeted */

	unsigned long	s_ntarguvhub16;		/* number of times target

						   hubs >= 16*/

	unsigned long	s_ntarguvhub8;		/* number of times target

						   hubs >= 8 */

	unsigned long	s_ntarguvhub4;		/* number of times target

						   hubs >= 4 */

	unsigned long	s_ntarguvhub2;		/* number of times target

						   hubs >= 2 */

	unsigned long	s_ntarguvhub1;		/* number of times target

						   hubs == 1 */

	unsigned long	s_resets_plug;		/* ipi-style resets from plug

						   state */

	unsigned long	s_resets_timeout;	/* ipi-style resets from

						   timeouts */

	unsigned long	s_busy;			/* status stayed busy past

						   s/w timer */

	unsigned long	s_throttles;		/* waits in throttle */

	unsigned long	s_retry_messages;	/* retry broadcasts */

	unsigned long	s_bau_reenabled;	/* for bau enable/disable */

	unsigned long	s_bau_disabled;		/* for bau enable/disable */

	/* destination statistics */

	unsigned long d_alltlb; /* times all tlb's on this cpu were flushed */

	unsigned long d_onetlb; /* times just one tlb on this cpu was flushed */

	unsigned long d_multmsg; /* interrupts with multiple messages */

	unsigned long	d_alltlb;		/* times all tlb's on this

						   cpu were flushed */

	unsigned long	d_onetlb;		/* times just one tlb on this

						   cpu was flushed */

	unsigned long	d_multmsg;		/* interrupts with multiple

						   messages */

	unsigned long	d_nomsg;		/* interrupts with no message */

	unsigned long d_time; /* time spent on destination side */

	unsigned long d_requestee; /* number of messages processed */

	unsigned long d_retries; /* number of retry messages processed */

	unsigned long d_canceled; /* number of messages canceled by retries */

	unsigned long d_nocanceled; /* retries that found nothing to cancel */

	unsigned long d_resets; /* number of ipi-style requests processed */

	unsigned long d_rcanceled; /* number of messages canceled by resets */

	unsigned long	d_time;			/* time spent on destination

						   side */

	unsigned long	d_requestee;		/* number of messages

						   processed */

	unsigned long	d_retries;		/* number of retry messages

						   processed */

	unsigned long	d_canceled;		/* number of messages canceled

						   by retries */

	unsigned long	d_nocanceled;		/* retries that found nothing

						   to cancel */

	unsigned long	d_resets;		/* number of ipi-style requests

						   processed */

	unsigned long	d_rcanceled;		/* number of messages canceled

						   by resets */

};



struct tunables {

	int			*tunp;

	int			deflt;

};



struct hub_and_pnode {

	short			uvhub;

	short			pnode;

};



struct socket_desc {

	short			num_cpus;

	short			cpu_number[MAX_CPUS_PER_SOCKET];

};



struct uvhub_desc {

	unsigned short		socket_mask;

	short			num_cpus;

	short			uvhub;

	short			pnode;

	struct socket_desc	socket[2];

};



/*

 * one per-cpu; to locate the software tables

 */

struct bau_control {

	struct bau_desc		*descriptor_base;

	struct bau_payload_queue_entry *va_queue_first;

	struct bau_payload_queue_entry *va_queue_last;

	struct bau_payload_queue_entry *bau_msg_head;

	struct bau_pq_entry	*queue_first;

	struct bau_pq_entry	*queue_last;

	struct bau_pq_entry	*bau_msg_head;

	struct bau_control	*uvhub_master;

	struct bau_control	*socket_master;

	struct ptc_stats	*statp;
@@ -452,35 +511,105 @@ struct bau_control { 
	spinlock_t		uvhub_lock;

	spinlock_t		queue_lock;

	/* tunables */

	int max_bau_concurrent;

	int max_bau_concurrent_constant;

	int			max_concurr;

	int			max_concurr_const;

	int			plugged_delay;

	int			plugsb4reset;

	int			timeoutsb4reset;

	int			ipi_reset_limit;

	int			complete_threshold;

	int congested_response_us;

	int congested_reps;

	int congested_period;

	int			cong_response_us;

	int			cong_reps;

	int			cong_period;

	cycles_t		period_time;

	long			period_requests;

	struct hub_and_pnode *target_hub_and_pnode;

	struct hub_and_pnode	*thp;

};



static inline int bau_uvhub_isset(int uvhub, struct bau_target_uvhubmask *dstp)

static unsigned long read_mmr_uv2_status(void)

{

	return read_lmmr(UV2H_LB_BAU_SB_ACTIVATION_STATUS_2);

}



static void write_mmr_data_broadcast(int pnode, unsigned long mmr_image)

{

	write_gmmr(pnode, UVH_BAU_DATA_BROADCAST, mmr_image);

}



static void write_mmr_descriptor_base(int pnode, unsigned long mmr_image)

{

	write_gmmr(pnode, UVH_LB_BAU_SB_DESCRIPTOR_BASE, mmr_image);

}



static void write_mmr_activation(unsigned long index)

{

	write_lmmr(UVH_LB_BAU_SB_ACTIVATION_CONTROL, index);

}



static void write_gmmr_activation(int pnode, unsigned long mmr_image)

{

	write_gmmr(pnode, UVH_LB_BAU_SB_ACTIVATION_CONTROL, mmr_image);

}



static void write_mmr_payload_first(int pnode, unsigned long mmr_image)

{

	write_gmmr(pnode, UVH_LB_BAU_INTD_PAYLOAD_QUEUE_FIRST, mmr_image);

}



static void write_mmr_payload_tail(int pnode, unsigned long mmr_image)

{

	write_gmmr(pnode, UVH_LB_BAU_INTD_PAYLOAD_QUEUE_TAIL, mmr_image);

}



static void write_mmr_payload_last(int pnode, unsigned long mmr_image)

{

	write_gmmr(pnode, UVH_LB_BAU_INTD_PAYLOAD_QUEUE_LAST, mmr_image);

}



static void write_mmr_misc_control(int pnode, unsigned long mmr_image)

{

	write_gmmr(pnode, UVH_LB_BAU_MISC_CONTROL, mmr_image);

}



static unsigned long read_mmr_misc_control(int pnode)

{

	return read_gmmr(pnode, UVH_LB_BAU_MISC_CONTROL);

}



static void write_mmr_sw_ack(unsigned long mr)

{

	uv_write_local_mmr(UVH_LB_BAU_INTD_SOFTWARE_ACKNOWLEDGE_ALIAS, mr);

}



static unsigned long read_mmr_sw_ack(void)

{

	return read_lmmr(UVH_LB_BAU_INTD_SOFTWARE_ACKNOWLEDGE);

}



static unsigned long read_gmmr_sw_ack(int pnode)

{

	return read_gmmr(pnode, UVH_LB_BAU_INTD_SOFTWARE_ACKNOWLEDGE);

}



static void write_mmr_data_config(int pnode, unsigned long mr)

{

	uv_write_global_mmr64(pnode, UVH_BAU_DATA_CONFIG, mr);

}



static inline int bau_uvhub_isset(int uvhub, struct bau_targ_hubmask *dstp)

{

	return constant_test_bit(uvhub, &dstp->bits[0]);

}

static inline void bau_uvhub_set(int pnode, struct bau_target_uvhubmask *dstp)

static inline void bau_uvhub_set(int pnode, struct bau_targ_hubmask *dstp)

{

	__set_bit(pnode, &dstp->bits[0]);

}

static inline void bau_uvhubs_clear(struct bau_target_uvhubmask *dstp,

static inline void bau_uvhubs_clear(struct bau_targ_hubmask *dstp,

				    int nbits)

{

	bitmap_zero(&dstp->bits[0], nbits);

}

static inline int bau_uvhub_weight(struct bau_target_uvhubmask *dstp)

static inline int bau_uvhub_weight(struct bau_targ_hubmask *dstp)

{

	return bitmap_weight((unsigned long *)&dstp->bits[0],

				UV_DISTRIBUTION_SIZE);
@@ -491,9 +620,6 @@ static inline void bau_cpubits_clear(struct bau_local_cpumask *dstp, int nbits) 
	bitmap_zero(&dstp->bits, nbits);

}



#define cpubit_isset(cpu, bau_local_cpumask) \

	test_bit((cpu), (bau_local_cpumask).bits)



extern void uv_bau_message_intr1(void);

extern void uv_bau_timeout_intr1(void);
@@ -501,7 +627,7 @@ struct atomic_short { 
	short counter;

};



/**

/*

 * atomic_read_short - read a short atomic variable

 * @v: pointer of type atomic_short

 *
@@ -512,14 +638,14 @@ static inline int atomic_read_short(const struct atomic_short *v) 
	return v->counter;

}



/**

 * atomic_add_short_return - add and return a short int

/*

 * atom_asr - add and return a short int

 * @i: short value to add

 * @v: pointer of type atomic_short

 *

 * Atomically adds @i to @v and returns @i + @v

 */

static inline int atomic_add_short_return(short i, struct atomic_short *v)

static inline int atom_asr(short i, struct atomic_short *v)

{

	short __i = i;

	asm volatile(LOCK_PREFIX "xaddw %0, %1"
@@ -528,4 +654,26 @@ static inline int atomic_add_short_return(short i, struct atomic_short *v) 
	return i + __i;

}



/*

 * conditionally add 1 to *v, unless *v is >= u

 * return 0 if we cannot add 1 to *v because it is >= u

 * return 1 if we can add 1 to *v because it is < u

 * the add is atomic

 *

 * This is close to atomic_add_unless(), but this allows the 'u' value

 * to be lowered below the current 'v'.  atomic_add_unless can only stop

 * on equal.

 */

static inline int atomic_inc_unless_ge(spinlock_t *lock, atomic_t *v, int u)

{

	spin_lock(lock);

	if (atomic_read(v) >= u) {

		spin_unlock(lock);

		return 0;

	}

	atomic_inc(v);

	spin_unlock(lock);

	return 1;

}



#endif /* _ASM_X86_UV_UV_BAU_H */

CRA Git | Maintained and supported by SUSTech CRA and CCSE