ide: fix IDE port slots reservation and freeing (take 2)

* Make ide_find_port_slot() return port slot index.

* Add ide_free_port_slot() helper.

* Move ide_init_port_data() call and error printk() from
  ide_find_port_slot() to ide_host_alloc_all().

* Make ide_{find,free}_port_slot() take ide_cfg_mtx mutex
  and convert them use ide_indexes bitmap to keep track of
  reserved port slots.

* Don't set hwif->chipset in ide_host_alloc_all() as it is
  no longer necessary.

v2:
* Pass the correct slot index to ide_init_port_data().

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 50 insertions, 37 deletions

diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index 32261282371a..fdf00cde9fce 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -1470,18 +1470,20 @@ static int ide_sysfs_register_port(ide_hwif_t *hwif)
         return rc;
 }
 
+static unsigned int ide_indexes;
+
 /**
- *      ide_find_port_slot      -       find free ide_hwifs[] slot
+ *      ide_find_port_slot      -       find free port slot
  *      @d: IDE port info
  *
- *      Return the new hwif.  If we are out of free slots return NULL.
+ *      Return the new port slot index or -ENOENT if we are out of free slots.
  */
 
-static ide_hwif_t *ide_find_port_slot(const struct ide_port_info *d)
+static int ide_find_port_slot(const struct ide_port_info *d)
 {
-        ide_hwif_t *hwif;
-        int i;
+        int idx = -ENOENT;
         u8 bootable = (d && (d->host_flags & IDE_HFLAG_NON_BOOTABLE)) ? 0 : 1;
+        u8 i = (d && (d->host_flags & IDE_HFLAG_QD_2ND_PORT)) ? 1 : 0;;
 
         /*
          * Claim an unassigned slot.
@@ -1493,35 +1495,33 @@ static ide_hwif_t *ide_find_port_slot(const struct ide_port_info *d)
          * Unless there is a bootable card that does not use the standard
          * ports 0x1f0/0x170 (the ide0/ide1 defaults).
          */
-        if (bootable) {
-                i = (d && (d->host_flags & IDE_HFLAG_QD_2ND_PORT)) ? 1 : 0;
-
-                for (; i < MAX_HWIFS; i++) {
-                        hwif = &ide_hwifs[i];
-                        if (hwif->chipset == ide_unknown)
-                                goto out_found;
-                }
+        mutex_lock(&ide_cfg_mtx);
+        if (MAX_HWIFS == 1) {
+                if (ide_indexes == 0 && i == 0)
+                        idx = 1;
         } else {
-                for (i = 2; i < MAX_HWIFS; i++) {
-                        hwif = &ide_hwifs[i];
-                        if (hwif->chipset == ide_unknown)
-                                goto out_found;
-                }
-                for (i = 0; i < 2 && i < MAX_HWIFS; i++) {
-                        hwif = &ide_hwifs[i];
-                        if (hwif->chipset == ide_unknown)
-                                goto out_found;
+                if (bootable) {
+                        if ((ide_indexes | i) != (1 << MAX_HWIFS) - 1)
+                                idx = ffz(ide_indexes | i);
+                } else {
+                        if ((ide_indexes | 3) != (1 << MAX_HWIFS) - 1)
+                                idx = ffz(ide_indexes | 3);
+                        else if ((ide_indexes & 3) != 3)
+                                idx = ffz(ide_indexes);
                 }
         }
+        if (idx >= 0)
+                ide_indexes |= (1 << idx);
+        mutex_unlock(&ide_cfg_mtx);
 
-        printk(KERN_ERR "%s: no free slot for interface\n",
-                        d ? d->name : "ide");
-
-        return NULL;
+        return idx;
+}
 
-out_found:
-        ide_init_port_data(hwif, i);
-        return hwif;
+static void ide_free_port_slot(int idx)
+{
+        mutex_lock(&ide_cfg_mtx);
+        ide_indexes &= ~(1 << idx);
+        mutex_unlock(&ide_cfg_mtx);
 }
 
 struct ide_host *ide_host_alloc_all(const struct ide_port_info *d,
@@ -1536,17 +1536,24 @@ struct ide_host *ide_host_alloc_all(const struct ide_port_info *d,
 
         for (i = 0; i < MAX_HWIFS; i++) {
                 ide_hwif_t *hwif;
+                int idx;
 
                 if (hws[i] == NULL)
                         continue;
 
-                hwif = ide_find_port_slot(d);
-                if (hwif) {
-                        hwif->chipset = hws[i]->chipset;
-
-                        host->ports[i] = hwif;
-                        host->n_ports++;
+                idx = ide_find_port_slot(d);
+                if (idx < 0) {
+                        printk(KERN_ERR "%s: no free slot for interface\n",
+                                        d ? d->name : "ide");
+                        continue;
                 }
+
+                hwif = &ide_hwifs[idx];
+
+                ide_init_port_data(hwif, idx);
+
+                host->ports[i] = hwif;
+                host->n_ports++;
         }
 
         if (host->n_ports == 0) {
@@ -1695,11 +1702,17 @@ EXPORT_SYMBOL_GPL(ide_host_add);
 
 void ide_host_remove(struct ide_host *host)
 {
+        ide_hwif_t *hwif;
         int i;
 
         for (i = 0; i < MAX_HWIFS; i++) {
-                if (host->ports[i])
-                        ide_unregister(host->ports[i]);
+                hwif = host->ports[i];
+
+                if (hwif == NULL)
+                        continue;
+
+                ide_unregister(hwif);
+                ide_free_port_slot(hwif->index);
         }
 
         kfree(host);