grukservices.h

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/*
 *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
 *
 *  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.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */
#ifndef __GRU_KSERVICES_H_
#define __GRU_KSERVICES_H_


/*
 * Message queues using the GRU to send/receive messages.
 *
 * These function allow the user to create a message queue for
 * sending/receiving 1 or 2 cacheline messages using the GRU.
 *
 * Processes SENDING messages will use a kernel CBR/DSR to send
 * the message. This is transparent to the caller.
 *
 * The receiver does not use any GRU resources.
 *
 * The functions support:
 *  - single receiver
 *  - multiple senders
 *  - cross partition message
 *
 * Missing features ZZZ:
 *  - user options for dealing with timeouts, queue full, etc.
 *  - gru_create_message_queue() needs interrupt vector info
 */

struct gru_message_queue_desc {
    void        *mq;            /* message queue vaddress */
    unsigned long   mq_gpa;         /* global address of mq */
    int     qlines;         /* queue size in CL */
    int     interrupt_vector;   /* interrupt vector */
    int     interrupt_pnode;    /* pnode for interrupt */
    int     interrupt_apicid;   /* lapicid for interrupt */
};

/*
 * Initialize a user allocated chunk of memory to be used as
 * a message queue. The caller must ensure that the queue is
 * in contiguous physical memory and is cacheline aligned.
 *
 * Message queue size is the total number of bytes allocated
 * to the queue including a 2 cacheline header that is used
 * to manage the queue.
 *
 *  Input:
 *  mqd pointer to message queue descriptor
 *  p   pointer to user allocated mesq memory.
 *  bytes   size of message queue in bytes
 *      vector  interrupt vector (zero if no interrupts)
 *      nasid   nasid of blade where interrupt is delivered
 *      apicid  apicid of cpu for interrupt
 *
 *  Errors:
 *      0   OK
 *      >0  error
 */
extern int gru_create_message_queue(struct gru_message_queue_desc *mqd,
        void *p, unsigned int bytes, int nasid, int vector, int apicid);

/*
 * Send a message to a message queue.
 *
 * Note: The message queue transport mechanism uses the first 32
 * bits of the message. Users should avoid using these bits.
 *
 *
 *   Input:
 *  mqd pointer to message queue descriptor
 *  mesg    pointer to message. Must be 64-bit aligned
 *  bytes   size of message in bytes
 *
 *   Output:
 *      0   message sent
 *     >0   Send failure - see error codes below
 *
 */
extern int gru_send_message_gpa(struct gru_message_queue_desc *mqd,
            void *mesg, unsigned int bytes);

/* Status values for gru_send_message() */
#define MQE_OK          0   /* message sent successfully */
#define MQE_CONGESTION      1   /* temporary congestion, try again */
#define MQE_QUEUE_FULL      2   /* queue is full */
#define MQE_UNEXPECTED_CB_ERR   3   /* unexpected CB error */
#define MQE_PAGE_OVERFLOW   10  /* BUG - queue overflowed a page */
#define MQE_BUG_NO_RESOURCES    11  /* BUG - could not alloc GRU cb/dsr */

/*
 * Advance the receive pointer for the message queue to the next message.
 * Note: current API requires messages to be gotten & freed in order. Future
 * API extensions may allow for out-of-order freeing.
 *
 *   Input
 *  mqd pointer to message queue descriptor
 *  mesq    message being freed
 */
extern void gru_free_message(struct gru_message_queue_desc *mqd,
                 void *mesq);

/*
 * Get next message from message queue. Returns pointer to
 * message OR NULL if no message present.
 * User must call gru_free_message() after message is processed
 * in order to move the queue pointers to next message.
 *
 *   Input
 *  mqd pointer to message queue descriptor
 *
 *   Output:
 *  p   pointer to message
 *  NULL    no message available
 */
extern void *gru_get_next_message(struct gru_message_queue_desc *mqd);


/*
 * Read a GRU global GPA. Source can be located in a remote partition.
 *
 *    Input:
 *      value       memory address where MMR value is returned
 *      gpa     source numalink physical address of GPA
 *
 *    Output:
 *  0       OK
 *  >0      error
 */
int gru_read_gpa(unsigned long *value, unsigned long gpa);


/*
 * Copy data using the GRU. Source or destination can be located in a remote
 * partition.
 *
 *    Input:
 *      dest_gpa    destination global physical address
 *      src_gpa     source global physical address
 *      bytes       number of bytes to copy
 *
 *    Output:
 *  0       OK
 *  >0      error
 */
extern int gru_copy_gpa(unsigned long dest_gpa, unsigned long src_gpa,
                            unsigned int bytes);

/*
 * Reserve GRU resources to be used asynchronously.
 *
 *  input:
 *      blade_id  - blade on which resources should be reserved
 *      cbrs      - number of CBRs
 *      dsr_bytes - number of DSR bytes needed
 *      cmp   - completion structure for waiting for
 *              async completions
 *  output:
 *      handle to identify resource
 *      (0 = no resources)
 */
extern unsigned long gru_reserve_async_resources(int blade_id, int cbrs, int dsr_bytes,
                struct completion *cmp);

/*
 * Release async resources previously reserved.
 *
 *  input:
 *      han - handle to identify resources
 */
extern void gru_release_async_resources(unsigned long han);

/*
 * Wait for async GRU instructions to complete.
 *
 *  input:
 *      han - handle to identify resources
 */
extern void gru_wait_async_cbr(unsigned long han);

/*
 * Lock previous reserved async GRU resources
 *
 *  input:
 *      han - handle to identify resources
 *  output:
 *      cb  - pointer to first CBR
 *      dsr - pointer to first DSR
 */
extern void gru_lock_async_resource(unsigned long han,  void **cb, void **dsr);

/*
 * Unlock previous reserved async GRU resources
 *
 *  input:
 *      han - handle to identify resources
 */
extern void gru_unlock_async_resource(unsigned long han);

#endif      /* __GRU_KSERVICES_H_ */