uv_bau.h

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * SGI UV Broadcast Assist Unit definitions
 *
 * Copyright (C) 2008 Silicon Graphics, Inc. All rights reserved.
 */

#ifndef _ASM_X86_UV_UV_BAU_H
#define _ASM_X86_UV_UV_BAU_H

#include <linux/bitmap.h>
#define BITSPERBYTE 8

/*
 * Broadcast Assist Unit messaging structures
 *
 * Selective Broadcast activations are induced by software action
 * specifying a particular 8-descriptor "set" via a 6-bit index written
 * to an MMR.
 * Thus there are 64 unique 512-byte sets of SB descriptors - one set for
 * each 6-bit index value. These descriptor sets are mapped in sequence
 * starting with set 0 located at the address specified in the
 * BAU_SB_DESCRIPTOR_BASE register, set 1 is located at BASE + 512,
 * set 2 is at BASE + 2*512, set 3 at BASE + 3*512, and so on.
 *
 * We will use 31 sets, one for sending BAU messages from each of the 32
 * cpu's on the uvhub.
 *
 * TLB shootdown will use the first of the 8 descriptors of each set.
 * Each of the descriptors is 64 bytes in size (8*64 = 512 bytes in a set).
 */

#define UV_ITEMS_PER_DESCRIPTOR		8
/* the 'throttle' to prevent the hardware stay-busy bug */
#define MAX_BAU_CONCURRENT		3
#define UV_CPUS_PER_ACT_STATUS		32
#define UV_ACT_STATUS_MASK		0x3
#define UV_ACT_STATUS_SIZE		2
#define UV_ADP_SIZE			32
#define UV_DISTRIBUTION_SIZE		256
#define UV_SW_ACK_NPENDING		8
#define UV_NET_ENDPOINT_INTD		0x38
#define UV_DESC_BASE_PNODE_SHIFT	49
#define UV_PAYLOADQ_PNODE_SHIFT		49
#define UV_PTC_BASENAME			"sgi_uv/ptc_statistics"
#define UV_BAU_BASENAME			"sgi_uv/bau_tunables"
#define UV_BAU_TUNABLES_DIR		"sgi_uv"
#define UV_BAU_TUNABLES_FILE		"bau_tunables"
#define WHITESPACE			" \t\n"
#define uv_physnodeaddr(x)		((__pa((unsigned long)(x)) & uv_mmask))
#define UV_ENABLE_INTD_SOFT_ACK_MODE_SHIFT 15
#define UV_INTD_SOFT_ACK_TIMEOUT_PERIOD_SHIFT 16
#define UV_INTD_SOFT_ACK_TIMEOUT_PERIOD 0x0000000009UL
/* [19:16] SOFT_ACK timeout period  19: 1 is urgency 7  17:16 1 is multiplier */
#define BAU_MISC_CONTROL_MULT_MASK 3

#define UVH_AGING_PRESCALE_SEL 0x000000b000UL
/* [30:28] URGENCY_7  an index into a table of times */
#define BAU_URGENCY_7_SHIFT 28
#define BAU_URGENCY_7_MASK 7

#define UVH_TRANSACTION_TIMEOUT 0x000000b200UL
/* [45:40] BAU - BAU transaction timeout select - a multiplier */
#define BAU_TRANS_SHIFT 40
#define BAU_TRANS_MASK 0x3f

/*
 * 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

/*
 * delay for 'plugged' timeout retries, in microseconds
 */
#define PLUGGED_DELAY			10

/*
 * threshholds at which to use IPI to free resources
 */
/* after this # consecutive 'plugged' timeouts, use IPI to release resources */
#define PLUGSB4RESET 100
/* after this many consecutive timeouts, use IPI to release resources */
#define TIMEOUTSB4RESET 1
/* at this number uses of IPI to release resources, giveup the request */
#define IPI_RESET_LIMIT 1
/* after this # consecutive successes, bump up the throttle if it was lowered */
#define COMPLETE_THRESHOLD 5

/*
 * number of entries in the destination side payload queue
 */
#define DEST_Q_SIZE			20
/*
 * number of destination side software ack resources
 */
#define DEST_NUM_RESOURCES		8
#define MAX_CPUS_PER_NODE		32
/*
 * completion statuses for sending a TLB flush message
 */
#define FLUSH_RETRY_PLUGGED		1
#define FLUSH_RETRY_TIMEOUT		2
#define FLUSH_GIVEUP			3
#define FLUSH_COMPLETE			4

/*
 * 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 */

/*
 * Distribution: 32 bytes (256 bits) (bytes 0-0x1f of descriptor)
 * If the 'multilevel' flag in the header portion of the descriptor
 * has been set to 0, then endpoint multi-unicast mode is selected.
 * The distribution specification (32 bytes) is interpreted as a 256-bit
 * distribution vector. Adjacent bits correspond to consecutive even numbered
 * nodeIDs. The result of adding the index of a given bit to the 15-bit
 * 'base_dest_nodeid' field of the header corresponds to the
 * destination nodeID associated with that specified bit.
 */
struct bau_target_uvhubmask {
	unsigned long bits[BITS_TO_LONGS(UV_DISTRIBUTION_SIZE)];
};

/*
 * mask of cpu's on a uvhub
 * (during initialization we need to check that unsigned long has
 *  enough bits for max. cpu's per uvhub)
 */
struct bau_local_cpumask {
	unsigned long bits;
};

/*
 * Payload: 16 bytes (128 bits) (bytes 0x20-0x2f of descriptor)
 * only 12 bytes (96 bits) of the payload area are usable.
 * An additional 3 bytes (bits 27:4) of the header address are carried
 * to the next bytes of the destination payload queue.
 * And an additional 2 bytes of the header Suppl_A field are also
 * carried to the destination payload queue.
 * But the first byte of the Suppl_A becomes bits 127:120 (the 16th byte)
 * of the destination payload queue, which is written by the hardware
 * with the s/w ack resource bit vector.
 * [ effective message contents (16 bytes (128 bits) maximum), not counting
 *   the s/w ack bit vector  ]
 */

/*
 * 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 */
	/* 64 bits */
	unsigned short sending_cpu;	/* filled in by sender */
	/* 16 bits */
	unsigned short acknowledge_count;/* filled in by destination */
	/* 16 bits */
	unsigned int reserved1:32;	/* not usable */
};


/*
 * Message header:  16 bytes (128 bits) (bytes 0x30-0x3f of descriptor)
 * see table 4.2.3.0.1 in broacast_assist spec.
 */
struct bau_msg_header {
	unsigned int dest_subnodeid:6;	/* must be 0x10, for the LB */
	/* bits 5:0 */
	unsigned int base_dest_nodeid:15; /* nasid (pnode<<1) of */
	/* bits 20:6 */			  /* first bit in uvhub map */
	unsigned int command:8;	/* message type */
	/* bits 28:21 */
				/* 0x38: SN3net EndPoint Message */
	unsigned int rsvd_1:3;	/* must be zero */
	/* bits 31:29 */
				/* int will align on 32 bits */
	unsigned int rsvd_2:9;	/* must be zero */
	/* bits 40:32 */
				/* 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) */

	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 */
	/* bit 58 */
	unsigned int msg_type:3; /* software type of the message*/
	/* bits 61:59 */
	unsigned int canceled:1; /* message canceled, resource to be freed*/
	/* bit 62 */
	unsigned int payload_1a:1;/* not currently used */
	/* bit 63 */
	unsigned int payload_1b:2;/* not currently used */
	/* bits 65:64 */

	/* bits 73:66 land in byte 13 */
	unsigned int payload_1ca:6;/* not currently used */
	/* bits 71:66 */
	unsigned int payload_1c:2;/* not currently used */
	/* bits 73:72 */

	/* bits 81:74 land in byte 14 */
	unsigned int payload_1d:6;/* not currently used */
	/* bits 79:74 */
	unsigned int payload_1e:2;/* not currently used */
	/* bits 81:80 */

	unsigned int rsvd_4:7;	/* must be zero */
	/* bits 88:82 */
	unsigned int sw_ack_flag:1;/* software acknowledge flag */
	/* bit 89 */
				/* 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 */
	/* bit 101*/
	unsigned int fairness:3;/* usually zero */
	/* bits 104:102 */
	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*/
	/* 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;
	/*
	 * message template, consisting of header and payload:
	 */
	struct bau_msg_header header;
	struct bau_msg_payload payload;
};
/*
 *   -payload--    ---------header------
 *   bytes 0-11    bits 41-56  bits 58-81
 *       A           B  (2)      C (3)
 *
 *            A/B/C are moved to:
 *       A            C          B
 *   bytes 0-11  bytes 12-14  bytes 16-17  (byte 15 filled in by hw as vector)
 *   ------------payload queue-----------
 */

/*
 * The payload queue on the destination side is an array of these.
 * With BAU_MISC_CONTROL set for software acknowledge mode, the messages
 * 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)
 * "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 {
	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 */
	/* 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;
	int msg_slot;
	int sw_ack_slot;
	struct bau_payload_queue_entry *va_queue_first;
	struct bau_payload_queue_entry *va_queue_last;
};

struct reset_args {
	int sender;
};

/*
 * This structure is allocated per_cpu for UV TLB shootdown statistics.
 */
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_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_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_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_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 */
};

/*
 * 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_control *uvhub_master;
	struct bau_control *socket_master;
	struct ptc_stats *statp;
	unsigned long timeout_interval;
	unsigned long set_bau_on_time;
	atomic_t active_descriptor_count;
	int plugged_tries;
	int timeout_tries;
	int ipi_attempts;
	int conseccompletes;
	int baudisabled;
	int set_bau_off;
	short cpu;
	short uvhub_cpu;
	short uvhub;
	short cpus_in_socket;
	short cpus_in_uvhub;
	unsigned short message_number;
	unsigned short uvhub_quiesce;
	short socket_acknowledge_count[DEST_Q_SIZE];
	cycles_t send_message;
	spinlock_t uvhub_lock;
	spinlock_t queue_lock;
	/* tunables */
	int max_bau_concurrent;
	int max_bau_concurrent_constant;
	int plugged_delay;
	int plugsb4reset;
	int timeoutsb4reset;
	int ipi_reset_limit;
	int complete_threshold;
	int congested_response_us;
	int congested_reps;
	int congested_period;
	cycles_t period_time;
	long period_requests;
};

static inline int bau_uvhub_isset(int uvhub, struct bau_target_uvhubmask *dstp)
{
	return constant_test_bit(uvhub, &dstp->bits[0]);
}
static inline void bau_uvhub_set(int uvhub, struct bau_target_uvhubmask *dstp)
{
	__set_bit(uvhub, &dstp->bits[0]);
}
static inline void bau_uvhubs_clear(struct bau_target_uvhubmask *dstp,
				    int nbits)
{
	bitmap_zero(&dstp->bits[0], nbits);
}
static inline int bau_uvhub_weight(struct bau_target_uvhubmask *dstp)
{
	return bitmap_weight((unsigned long *)&dstp->bits[0],
				UV_DISTRIBUTION_SIZE);
}

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);

struct atomic_short {
	short counter;
};

/**
 * atomic_read_short - read a short atomic variable
 * @v: pointer of type atomic_short
 *
 * Atomically reads the value of @v.
 */
static inline int atomic_read_short(const struct atomic_short *v)
{
	return v->counter;
}

/**
 * atomic_add_short_return - 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)
{
	short __i = i;
	asm volatile(LOCK_PREFIX "xaddw %0, %1"
			: "+r" (i), "+m" (v->counter)
			: : "memory");
	return i + __i;
}

#endif /* _ASM_X86_UV_UV_BAU_H */