linux/drivers/isdn/capi/capilib.c
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   1// SPDX-License-Identifier: GPL-2.0
   2
   3#include <linux/slab.h>
   4#include <linux/kernel.h>
   5#include <linux/module.h>
   6#include <linux/isdn/capilli.h>
   7
   8#define DBG(format, arg...) do {                                        \
   9                printk(KERN_DEBUG "%s: " format "\n" , __func__ , ## arg); \
  10        } while (0)
  11
  12struct capilib_msgidqueue {
  13        struct capilib_msgidqueue *next;
  14        u16 msgid;
  15};
  16
  17struct capilib_ncci {
  18        struct list_head list;
  19        u16 applid;
  20        u32 ncci;
  21        u32 winsize;
  22        int   nmsg;
  23        struct capilib_msgidqueue *msgidqueue;
  24        struct capilib_msgidqueue *msgidlast;
  25        struct capilib_msgidqueue *msgidfree;
  26        struct capilib_msgidqueue msgidpool[CAPI_MAXDATAWINDOW];
  27};
  28
  29// ---------------------------------------------------------------------------
  30// NCCI Handling
  31
  32static inline void mq_init(struct capilib_ncci *np)
  33{
  34        u_int i;
  35        np->msgidqueue = NULL;
  36        np->msgidlast = NULL;
  37        np->nmsg = 0;
  38        memset(np->msgidpool, 0, sizeof(np->msgidpool));
  39        np->msgidfree = &np->msgidpool[0];
  40        for (i = 1; i < np->winsize; i++) {
  41                np->msgidpool[i].next = np->msgidfree;
  42                np->msgidfree = &np->msgidpool[i];
  43        }
  44}
  45
  46static inline int mq_enqueue(struct capilib_ncci *np, u16 msgid)
  47{
  48        struct capilib_msgidqueue *mq;
  49        if ((mq = np->msgidfree) == NULL)
  50                return 0;
  51        np->msgidfree = mq->next;
  52        mq->msgid = msgid;
  53        mq->next = NULL;
  54        if (np->msgidlast)
  55                np->msgidlast->next = mq;
  56        np->msgidlast = mq;
  57        if (!np->msgidqueue)
  58                np->msgidqueue = mq;
  59        np->nmsg++;
  60        return 1;
  61}
  62
  63static inline int mq_dequeue(struct capilib_ncci *np, u16 msgid)
  64{
  65        struct capilib_msgidqueue **pp;
  66        for (pp = &np->msgidqueue; *pp; pp = &(*pp)->next) {
  67                if ((*pp)->msgid == msgid) {
  68                        struct capilib_msgidqueue *mq = *pp;
  69                        *pp = mq->next;
  70                        if (mq == np->msgidlast)
  71                                np->msgidlast = NULL;
  72                        mq->next = np->msgidfree;
  73                        np->msgidfree = mq;
  74                        np->nmsg--;
  75                        return 1;
  76                }
  77        }
  78        return 0;
  79}
  80
  81void capilib_new_ncci(struct list_head *head, u16 applid, u32 ncci, u32 winsize)
  82{
  83        struct capilib_ncci *np;
  84
  85        np = kmalloc(sizeof(*np), GFP_ATOMIC);
  86        if (!np) {
  87                printk(KERN_WARNING "capilib_new_ncci: no memory.\n");
  88                return;
  89        }
  90        if (winsize > CAPI_MAXDATAWINDOW) {
  91                printk(KERN_ERR "capi_new_ncci: winsize %d too big\n",
  92                       winsize);
  93                winsize = CAPI_MAXDATAWINDOW;
  94        }
  95        np->applid = applid;
  96        np->ncci = ncci;
  97        np->winsize = winsize;
  98        mq_init(np);
  99        list_add_tail(&np->list, head);
 100        DBG("kcapi: appl %d ncci 0x%x up", applid, ncci);
 101}
 102
 103EXPORT_SYMBOL(capilib_new_ncci);
 104
 105void capilib_free_ncci(struct list_head *head, u16 applid, u32 ncci)
 106{
 107        struct list_head *l;
 108        struct capilib_ncci *np;
 109
 110        list_for_each(l, head) {
 111                np = list_entry(l, struct capilib_ncci, list);
 112                if (np->applid != applid)
 113                        continue;
 114                if (np->ncci != ncci)
 115                        continue;
 116                printk(KERN_INFO "kcapi: appl %d ncci 0x%x down\n", applid, ncci);
 117                list_del(&np->list);
 118                kfree(np);
 119                return;
 120        }
 121        printk(KERN_ERR "capilib_free_ncci: ncci 0x%x not found\n", ncci);
 122}
 123
 124EXPORT_SYMBOL(capilib_free_ncci);
 125
 126void capilib_release_appl(struct list_head *head, u16 applid)
 127{
 128        struct list_head *l, *n;
 129        struct capilib_ncci *np;
 130
 131        list_for_each_safe(l, n, head) {
 132                np = list_entry(l, struct capilib_ncci, list);
 133                if (np->applid != applid)
 134                        continue;
 135                printk(KERN_INFO "kcapi: appl %d ncci 0x%x forced down\n", applid, np->ncci);
 136                list_del(&np->list);
 137                kfree(np);
 138        }
 139}
 140
 141EXPORT_SYMBOL(capilib_release_appl);
 142
 143void capilib_release(struct list_head *head)
 144{
 145        struct list_head *l, *n;
 146        struct capilib_ncci *np;
 147
 148        list_for_each_safe(l, n, head) {
 149                np = list_entry(l, struct capilib_ncci, list);
 150                printk(KERN_INFO "kcapi: appl %d ncci 0x%x forced down\n", np->applid, np->ncci);
 151                list_del(&np->list);
 152                kfree(np);
 153        }
 154}
 155
 156EXPORT_SYMBOL(capilib_release);
 157
 158u16 capilib_data_b3_req(struct list_head *head, u16 applid, u32 ncci, u16 msgid)
 159{
 160        struct list_head *l;
 161        struct capilib_ncci *np;
 162
 163        list_for_each(l, head) {
 164                np = list_entry(l, struct capilib_ncci, list);
 165                if (np->applid != applid)
 166                        continue;
 167                if (np->ncci != ncci)
 168                        continue;
 169
 170                if (mq_enqueue(np, msgid) == 0)
 171                        return CAPI_SENDQUEUEFULL;
 172
 173                return CAPI_NOERROR;
 174        }
 175        printk(KERN_ERR "capilib_data_b3_req: ncci 0x%x not found\n", ncci);
 176        return CAPI_NOERROR;
 177}
 178
 179EXPORT_SYMBOL(capilib_data_b3_req);
 180
 181void capilib_data_b3_conf(struct list_head *head, u16 applid, u32 ncci, u16 msgid)
 182{
 183        struct list_head *l;
 184        struct capilib_ncci *np;
 185
 186        list_for_each(l, head) {
 187                np = list_entry(l, struct capilib_ncci, list);
 188                if (np->applid != applid)
 189                        continue;
 190                if (np->ncci != ncci)
 191                        continue;
 192
 193                if (mq_dequeue(np, msgid) == 0) {
 194                        printk(KERN_ERR "kcapi: msgid %hu ncci 0x%x not on queue\n",
 195                               msgid, ncci);
 196                }
 197                return;
 198        }
 199        printk(KERN_ERR "capilib_data_b3_conf: ncci 0x%x not found\n", ncci);
 200}
 201
 202EXPORT_SYMBOL(capilib_data_b3_conf);
 203