cell/spufs/context.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * SPU file system -- SPU context management
0004  *
0005  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
0006  *
0007  * Author: Arnd Bergmann <arndb@de.ibm.com>
0008  */
0009
0010 #include <linux/fs.h>
0011 #include <linux/mm.h>
0012 #include <linux/slab.h>
0013 #include <linux/atomic.h>
0014 #include <linux/sched.h>
0015 #include <linux/sched/mm.h>
0016
0017 #include <asm/spu.h>
0018 #include <asm/spu_csa.h>
0019 #include "spufs.h"
0020 #include "sputrace.h"
0021
0022
0023 atomic_t nr_spu_contexts = ATOMIC_INIT(0);
0024
0025 struct spu_context *alloc_spu_context(struct spu_gang *gang)
0026 {
0027     struct spu_context *ctx;
0028
0029     ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
0030     if (!ctx)
0031         goto out;
0032     /* Binding to physical processor deferred
0033      * until spu_activate().
0034      */
0035     if (spu_init_csa(&ctx->csa))
0036         goto out_free;
0037     spin_lock_init(&ctx->mmio_lock);
0038     mutex_init(&ctx->mapping_lock);
0039     kref_init(&ctx->kref);
0040     mutex_init(&ctx->state_mutex);
0041     mutex_init(&ctx->run_mutex);
0042     init_waitqueue_head(&ctx->ibox_wq);
0043     init_waitqueue_head(&ctx->wbox_wq);
0044     init_waitqueue_head(&ctx->stop_wq);
0045     init_waitqueue_head(&ctx->mfc_wq);
0046     init_waitqueue_head(&ctx->run_wq);
0047     ctx->state = SPU_STATE_SAVED;
0048     ctx->ops = &spu_backing_ops;
0049     ctx->owner = get_task_mm(current);
0050     INIT_LIST_HEAD(&ctx->rq);
0051     INIT_LIST_HEAD(&ctx->aff_list);
0052     if (gang)
0053         spu_gang_add_ctx(gang, ctx);
0054
0055     __spu_update_sched_info(ctx);
0056     spu_set_timeslice(ctx);
0057     ctx->stats.util_state = SPU_UTIL_IDLE_LOADED;
0058     ctx->stats.tstamp = ktime_get_ns();
0059
0060     atomic_inc(&nr_spu_contexts);
0061     goto out;
0062 out_free:
0063     kfree(ctx);
0064     ctx = NULL;
0065 out:
0066     return ctx;
0067 }
0068
0069 void destroy_spu_context(struct kref *kref)
0070 {
0071     struct spu_context *ctx;
0072     ctx = container_of(kref, struct spu_context, kref);
0073     spu_context_nospu_trace(destroy_spu_context__enter, ctx);
0074     mutex_lock(&ctx->state_mutex);
0075     spu_deactivate(ctx);
0076     mutex_unlock(&ctx->state_mutex);
0077     spu_fini_csa(&ctx->csa);
0078     if (ctx->gang)
0079         spu_gang_remove_ctx(ctx->gang, ctx);
0080     if (ctx->prof_priv_kref)
0081         kref_put(ctx->prof_priv_kref, ctx->prof_priv_release);
0082     BUG_ON(!list_empty(&ctx->rq));
0083     atomic_dec(&nr_spu_contexts);
0084     kfree(ctx->switch_log);
0085     kfree(ctx);
0086 }
0087
0088 struct spu_context * get_spu_context(struct spu_context *ctx)
0089 {
0090     kref_get(&ctx->kref);
0091     return ctx;
0092 }
0093
0094 int put_spu_context(struct spu_context *ctx)
0095 {
0096     return kref_put(&ctx->kref, &destroy_spu_context);
0097 }
0098
0099 /* give up the mm reference when the context is about to be destroyed */
0100 void spu_forget(struct spu_context *ctx)
0101 {
0102     struct mm_struct *mm;
0103
0104     /*
0105      * This is basically an open-coded spu_acquire_saved, except that
0106      * we don't acquire the state mutex interruptible, and we don't
0107      * want this context to be rescheduled on release.
0108      */
0109     mutex_lock(&ctx->state_mutex);
0110     if (ctx->state != SPU_STATE_SAVED)
0111         spu_deactivate(ctx);
0112
0113     mm = ctx->owner;
0114     ctx->owner = NULL;
0115     mmput(mm);
0116     spu_release(ctx);
0117 }
0118
0119 void spu_unmap_mappings(struct spu_context *ctx)
0120 {
0121     mutex_lock(&ctx->mapping_lock);
0122     if (ctx->local_store)
0123         unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
0124     if (ctx->mfc)
0125         unmap_mapping_range(ctx->mfc, 0, SPUFS_MFC_MAP_SIZE, 1);
0126     if (ctx->cntl)
0127         unmap_mapping_range(ctx->cntl, 0, SPUFS_CNTL_MAP_SIZE, 1);
0128     if (ctx->signal1)
0129         unmap_mapping_range(ctx->signal1, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
0130     if (ctx->signal2)
0131         unmap_mapping_range(ctx->signal2, 0, SPUFS_SIGNAL_MAP_SIZE, 1);
0132     if (ctx->mss)
0133         unmap_mapping_range(ctx->mss, 0, SPUFS_MSS_MAP_SIZE, 1);
0134     if (ctx->psmap)
0135         unmap_mapping_range(ctx->psmap, 0, SPUFS_PS_MAP_SIZE, 1);
0136     mutex_unlock(&ctx->mapping_lock);
0137 }
0138
0139 /**
0140  * spu_acquire_saved - lock spu contex and make sure it is in saved state
0141  * @ctx:    spu contex to lock
0142  */
0143 int spu_acquire_saved(struct spu_context *ctx)
0144 {
0145     int ret;
0146
0147     spu_context_nospu_trace(spu_acquire_saved__enter, ctx);
0148
0149     ret = spu_acquire(ctx);
0150     if (ret)
0151         return ret;
0152
0153     if (ctx->state != SPU_STATE_SAVED) {
0154         set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags);
0155         spu_deactivate(ctx);
0156     }
0157
0158     return 0;
0159 }
0160
0161 /**
0162  * spu_release_saved - unlock spu context and return it to the runqueue
0163  * @ctx:    context to unlock
0164  */
0165 void spu_release_saved(struct spu_context *ctx)
0166 {
0167     BUG_ON(ctx->state != SPU_STATE_SAVED);
0168
0169     if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags) &&
0170             test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags))
0171         spu_activate(ctx, 0);
0172
0173     spu_release(ctx);
0174 }
0175