arch/powerpc/platforms/cell/spufs/context.c

   1 /*
   2  * SPU file system -- SPU context management
   3  *
   4  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
   5  *
   6  * Author: Arnd Bergmann <arndb@de.ibm.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  */
  22
  23 #include <linux/fs.h>
  24 #include <linux/mm.h>
  25 #include <linux/module.h>
  26 #include <linux/slab.h>
  27 #include <asm/atomic.h>
  28 #include <asm/spu.h>
  29 #include <asm/spu_csa.h>
  30 #include "spufs.h"
  31
  32
  33 atomic_t nr_spu_contexts = ATOMIC_INIT(0);
  34
  35 struct spu_context *alloc_spu_context(struct spu_gang *gang)
  36 {
  37         struct spu_context *ctx;
  38         ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
  39         if (!ctx)
  40                 goto out;
  41         /* Binding to physical processor deferred
  42          * until spu_activate().
  43          */
  44         if (spu_init_csa(&ctx->csa))
  45                 goto out_free;
  46         spin_lock_init(&ctx->mmio_lock);
  47         mutex_init(&ctx->mapping_lock);
  48         kref_init(&ctx->kref);
  49         mutex_init(&ctx->state_mutex);
  50         mutex_init(&ctx->run_mutex);
  51         init_waitqueue_head(&ctx->ibox_wq);
  52         init_waitqueue_head(&ctx->wbox_wq);
  53         init_waitqueue_head(&ctx->stop_wq);
  54         init_waitqueue_head(&ctx->mfc_wq);
  55         init_waitqueue_head(&ctx->run_wq);
  56         ctx->state = SPU_STATE_SAVED;
  57         ctx->ops = &spu_backing_ops;
  58         ctx->owner = get_task_mm(current);
  59         INIT_LIST_HEAD(&ctx->rq);
  60         INIT_LIST_HEAD(&ctx->aff_list);
  61         if (gang)
  62                 spu_gang_add_ctx(gang, ctx);
  63
  64         __spu_update_sched_info(ctx);
  65         spu_set_timeslice(ctx);
  66         ctx->stats.util_state = SPU_UTIL_IDLE_LOADED;
  67
  68         atomic_inc(&nr_spu_contexts);
  69         goto out;
  70 out_free:
  71         kfree(ctx);
  72         ctx = NULL;
  73 out:
  74         return ctx;
  75 }
  76
  77 void destroy_spu_context(struct kref *kref)
  78 {
  79         struct spu_context *ctx;
  80         ctx = container_of(kref, struct spu_context, kref);
  81         mutex_lock(&ctx->state_mutex);
  82         spu_deactivate(ctx);
  83         mutex_unlock(&ctx->state_mutex);
  84         spu_fini_csa(&ctx->csa);
  85         if (ctx->gang)
  86                 spu_gang_remove_ctx(ctx->gang, ctx);
  87         if (ctx->prof_priv_kref)
  88                 kref_put(ctx->prof_priv_kref, ctx->prof_priv_release);
  89         BUG_ON(!list_empty(&ctx->rq));
  90         atomic_dec(&nr_spu_contexts);
  91         kfree(ctx);
  92 }
  93
  94 struct spu_context * get_spu_context(struct spu_context *ctx)
  95 {
  96         kref_get(&ctx->kref);
  97         return ctx;
  98 }
  99
 100 int put_spu_context(struct spu_context *ctx)
 101 {
 102         return kref_put(&ctx->kref, &destroy_spu_context);
 103 }
 104
 105 /* give up the mm reference when the context is about to be destroyed */
 106 void spu_forget(struct spu_context *ctx)
 107 {
 108         struct mm_struct *mm;
 109
 110         /*
 111          * This is basically an open-coded spu_acquire_saved, except that
 112          * we don't acquire the state mutex interruptible, and we don't
 113          * want this context to be rescheduled on release.
 114          */
 115         mutex_lock(&ctx->state_mutex);
 116         if (ctx->state != SPU_STATE_SAVED)
 117                 spu_deactivate(ctx);
 118
 119         mm = ctx->owner;
 120         ctx->owner = NULL;
 121         mmput(mm);
 122         spu_release(ctx);
 123 }
 124
 125 void spu_unmap_mappings(struct spu_context *ctx)
 126 {
 127         mutex_lock(&ctx->mapping_lock);
 128         if (ctx->local_store)
 129                 unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
 130         if (ctx->mfc)
 131                 unmap_mapping_range(ctx->mfc, 0, 0x1000, 1);
 132         if (ctx->cntl)
 133                 unmap_mapping_range(ctx->cntl, 0, 0x1000, 1);
 134         if (ctx->signal1)
 135                 unmap_mapping_range(ctx->signal1, 0, PAGE_SIZE, 1);
 136         if (ctx->signal2)
 137                 unmap_mapping_range(ctx->signal2, 0, PAGE_SIZE, 1);
 138         if (ctx->mss)
 139                 unmap_mapping_range(ctx->mss, 0, 0x1000, 1);
 140         if (ctx->psmap)
 141                 unmap_mapping_range(ctx->psmap, 0, 0x20000, 1);
 142         mutex_unlock(&ctx->mapping_lock);
 143 }
 144
 145 /**
 146  * spu_acquire_saved - lock spu contex and make sure it is in saved state
 147  * @ctx:        spu contex to lock
 148  */
 149 int spu_acquire_saved(struct spu_context *ctx)
 150 {
 151         int ret;
 152
 153         ret = spu_acquire(ctx);
 154         if (ret)
 155                 return ret;
 156
 157         if (ctx->state != SPU_STATE_SAVED) {
 158                 set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags);
 159                 spu_deactivate(ctx);
 160         }
 161
 162         return 0;
 163 }
 164
 165 /**
 166  * spu_release_saved - unlock spu context and return it to the runqueue
 167  * @ctx:        context to unlock
 168  */
 169 void spu_release_saved(struct spu_context *ctx)
 170 {
 171         BUG_ON(ctx->state != SPU_STATE_SAVED);
 172
 173         if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags) &&
 174                         test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags))
 175                 spu_activate(ctx, 0);
 176
 177         spu_release(ctx);
 178 }
 179