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

DEFINITIONS

1. alloc_spu_context
2. destroy_spu_context
3. get_spu_context
4. put_spu_context
5. spu_forget
6. spu_unmap_mappings
7. spu_acquire_saved
8. spu_release_saved

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * SPU file system -- SPU context management
   4  *
   5  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
   6  *
   7  * Author: Arnd Bergmann <arndb@de.ibm.com>
   8  */
   9 
  10 #include <linux/fs.h>
  11 #include <linux/mm.h>
  12 #include <linux/slab.h>
  13 #include <linux/atomic.h>
  14 #include <linux/sched.h>
  15 #include <linux/sched/mm.h>
  16 
  17 #include <asm/spu.h>
  18 #include <asm/spu_csa.h>
  19 #include "spufs.h"
  20 #include "sputrace.h"
  21 
  22 
  23 atomic_t nr_spu_contexts = ATOMIC_INIT(0);
  24 
  25 struct spu_context *alloc_spu_context(struct spu_gang *gang)
  26 {
  27         struct spu_context *ctx;
  28 
  29         ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
  30         if (!ctx)
  31                 goto out;
  32         /* Binding to physical processor deferred
  33          * until spu_activate().
  34          */
  35         if (spu_init_csa(&ctx->csa))
  36                 goto out_free;
  37         spin_lock_init(&ctx->mmio_lock);
  38         mutex_init(&ctx->mapping_lock);
  39         kref_init(&ctx->kref);
  40         mutex_init(&ctx->state_mutex);
  41         mutex_init(&ctx->run_mutex);
  42         init_waitqueue_head(&ctx->ibox_wq);
  43         init_waitqueue_head(&ctx->wbox_wq);
  44         init_waitqueue_head(&ctx->stop_wq);
  45         init_waitqueue_head(&ctx->mfc_wq);
  46         init_waitqueue_head(&ctx->run_wq);
  47         ctx->state = SPU_STATE_SAVED;
  48         ctx->ops = &spu_backing_ops;
  49         ctx->owner = get_task_mm(current);
  50         INIT_LIST_HEAD(&ctx->rq);
  51         INIT_LIST_HEAD(&ctx->aff_list);
  52         if (gang)
  53                 spu_gang_add_ctx(gang, ctx);
  54 
  55         __spu_update_sched_info(ctx);
  56         spu_set_timeslice(ctx);
  57         ctx->stats.util_state = SPU_UTIL_IDLE_LOADED;
  58         ctx->stats.tstamp = ktime_get_ns();
  59 
  60         atomic_inc(&nr_spu_contexts);
  61         goto out;
  62 out_free:
  63         kfree(ctx);
  64         ctx = NULL;
  65 out:
  66         return ctx;
  67 }
  68 
  69 void destroy_spu_context(struct kref *kref)
  70 {
  71         struct spu_context *ctx;
  72         ctx = container_of(kref, struct spu_context, kref);
  73         spu_context_nospu_trace(destroy_spu_context__enter, ctx);
  74         mutex_lock(&ctx->state_mutex);
  75         spu_deactivate(ctx);
  76         mutex_unlock(&ctx->state_mutex);
  77         spu_fini_csa(&ctx->csa);
  78         if (ctx->gang)
  79                 spu_gang_remove_ctx(ctx->gang, ctx);
  80         if (ctx->prof_priv_kref)
  81                 kref_put(ctx->prof_priv_kref, ctx->prof_priv_release);
  82         BUG_ON(!list_empty(&ctx->rq));
  83         atomic_dec(&nr_spu_contexts);
  84         kfree(ctx->switch_log);
  85         kfree(ctx);
  86 }
  87 
  88 struct spu_context * get_spu_context(struct spu_context *ctx)
  89 {
  90         kref_get(&ctx->kref);
  91         return ctx;
  92 }
  93 
  94 int put_spu_context(struct spu_context *ctx)
  95 {
  96         return kref_put(&ctx->kref, &destroy_spu_context);
  97 }
  98 
  99 /* give up the mm reference when the context is about to be destroyed */
 100 void spu_forget(struct spu_context *ctx)
 101 {
 102         struct mm_struct *mm;
 103 
 104         /*
 105          * This is basically an open-coded spu_acquire_saved, except that
 106          * we don't acquire the state mutex interruptible, and we don't
 107          * want this context to be rescheduled on release.
 108          */
 109         mutex_lock(&ctx->state_mutex);
 110         if (ctx->state != SPU_STATE_SAVED)
 111                 spu_deactivate(ctx);
 112 
 113         mm = ctx->owner;
 114         ctx->owner = NULL;
 115         mmput(mm);
 116         spu_release(ctx);
 117 }
 118 
 119 void spu_unmap_mappings(struct spu_context *ctx)
 120 {
 121         mutex_lock(&ctx->mapping_lock);
 122         if (ctx->local_store)
 123                 unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
 124         if (ctx->mfc)
 125                 unmap_mapping_range(ctx->mfc, 0, SPUFS_MFC_MAP_SIZE, 1);
 126         if (ctx->cntl)
 127                 unmap_mapping_range(ctx->cntl, 0, SPUFS_CNTL_MAP_SIZE, 1);
 128         if (ctx->signal1)
 129                 unmap_mapping_range(ctx->signal1, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
 130         if (ctx->signal2)
 131                 unmap_mapping_range(ctx->signal2, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
 132         if (ctx->mss)
 133                 unmap_mapping_range(ctx->mss, 0, SPUFS_MSS_MAP_SIZE, 1);
 134         if (ctx->psmap)
 135                 unmap_mapping_range(ctx->psmap, 0, SPUFS_PS_MAP_SIZE, 1);
 136         mutex_unlock(&ctx->mapping_lock);
 137 }
 138 
 139 /**
 140  * spu_acquire_saved - lock spu contex and make sure it is in saved state
 141  * @ctx:        spu contex to lock
 142  */
 143 int spu_acquire_saved(struct spu_context *ctx)
 144 {
 145         int ret;
 146 
 147         spu_context_nospu_trace(spu_acquire_saved__enter, ctx);
 148 
 149         ret = spu_acquire(ctx);
 150         if (ret)
 151                 return ret;
 152 
 153         if (ctx->state != SPU_STATE_SAVED) {
 154                 set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags);
 155                 spu_deactivate(ctx);
 156         }
 157 
 158         return 0;
 159 }
 160 
 161 /**
 162  * spu_release_saved - unlock spu context and return it to the runqueue
 163  * @ctx:        context to unlock
 164  */
 165 void spu_release_saved(struct spu_context *ctx)
 166 {
 167         BUG_ON(ctx->state != SPU_STATE_SAVED);
 168 
 169         if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags) &&
 170                         test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags))
 171                 spu_activate(ctx, 0);
 172 
 173         spu_release(ctx);
 174 }
 175