src/patches/suse-2.6.27.31/patches.drivers/ehca-rejecting-dynamic-mem-add-remove.patch

   1 Subject: [PATCH]IB/ehca:reject dynamic memory add/remove
   2 From: Stefan Roscher <ossrosch@linux.vnet.ibm.com>
   3 References: 434651 - LTC48744
   4
   5 Since the ehca device driver does not support dynamic memory add and remove
   6 operations, the driver must explicitly reject such requests in order to prevent
   7 unpredictable behaviors related to memory regions already occupied and being
   8 used by InfiniBand applications.
   9 The solution is to add a memory notifier to the ehca device driver and if a request
  10 for dynamic memory add or remove comes in, ehca will always reject it.
  11
  12 Signed-off-by: Stefan Roscher <stefan.roscher@de.ibm.com>
  13 Signed-off-by: Olaf Hering <olh@suse.de>
  14
  15 ---
  16  drivers/infiniband/hw/ehca/ehca_main.c |   46 +++++++++++++++++++++++++++++++++
  17  1 file changed, 46 insertions(+)
  18
  19 --- a/drivers/infiniband/hw/ehca/ehca_main.c
  20 +++ b/drivers/infiniband/hw/ehca/ehca_main.c
  21 @@ -44,6 +44,8 @@
  22  #include <linux/slab.h>
  23  #endif
  24
  25 +#include <linux/notifier.h>
  26 +#include <linux/memory.h>
  27  #include "ehca_classes.h"
  28  #include "ehca_iverbs.h"
  29  #include "ehca_mrmw.h"
  30 @@ -965,6 +967,39 @@ void ehca_poll_eqs(unsigned long data)
  31         spin_unlock(&shca_list_lock);
  32  }
  33
  34 +static int ehca_mem_notifier(struct notifier_block *nb,
  35 +                             unsigned long action, void *data)
  36 +{
  37 +       static unsigned long ehca_dmem_warn_time;
  38 +
  39 +       switch (action) {
  40 +       case MEM_CANCEL_OFFLINE:
  41 +       case MEM_CANCEL_ONLINE:
  42 +       case MEM_ONLINE:
  43 +       case MEM_OFFLINE:
  44 +               return NOTIFY_OK;
  45 +       case MEM_GOING_ONLINE:
  46 +       case MEM_GOING_OFFLINE:
  47 +               /* only ok if no hca is attached to the lpar */
  48 +               spin_lock(&shca_list_lock);
  49 +               if (list_empty(&shca_list)) {
  50 +                       spin_unlock(&shca_list_lock);
  51 +                       return NOTIFY_OK;
  52 +               } else {
  53 +                       spin_unlock(&shca_list_lock);
  54 +                       if (printk_timed_ratelimit(&ehca_dmem_warn_time,
  55 +                                                  30 * 1000))
  56 +                               ehca_gen_err("DMEM operations are not allowed in conjunction with eHCA");
  57 +                       return NOTIFY_BAD;
  58 +               }
  59 +       }
  60 +       return NOTIFY_OK;
  61 +}
  62 +
  63 +static struct notifier_block ehca_mem_nb = {
  64 +       .notifier_call = ehca_mem_notifier,
  65 +};
  66 +
  67  static int __init ehca_module_init(void)
  68  {
  69         int ret;
  70 @@ -992,6 +1027,12 @@ static int __init ehca_module_init(void)
  71                 goto module_init2;
  72         }
  73
  74 +       ret = register_memory_notifier(&ehca_mem_nb);
  75 +       if (ret) {
  76 +               ehca_gen_err("Failed registering memory add/remove notifier");
  77 +               goto module_init3;
  78 +       }
  79 +
  80         if (ehca_poll_all_eqs != 1) {
  81                 ehca_gen_err("WARNING!!!");
  82                 ehca_gen_err("It is possible to lose interrupts.");
  83 @@ -1004,6 +1045,9 @@ static int __init ehca_module_init(void)
  84
  85         return 0;
  86
  87 +module_init3:
  88 +       ibmebus_unregister_driver(&ehca_driver);
  89 +
  90  module_init2:
  91         ehca_destroy_slab_caches();
  92
  93 @@ -1019,6 +1063,8 @@ static void __exit ehca_module_exit(void
  94
  95         ibmebus_unregister_driver(&ehca_driver);
  96
  97 +       unregister_memory_notifier(&ehca_mem_nb);
  98 +
  99         ehca_destroy_slab_caches();
 100
 101         ehca_destroy_comp_pool();