cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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context.c (4223B)

      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
     23atomic_t nr_spu_contexts = ATOMIC_INIT(0);
     24
     25struct 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;
     62out_free:
     63	kfree(ctx);
     64	ctx = NULL;
     65out:
     66	return ctx;
     67}
     68
     69void 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
     88struct spu_context * get_spu_context(struct spu_context *ctx)
     89{
     90	kref_get(&ctx->kref);
     91	return ctx;
     92}
     93
     94int 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 */
    100void 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
    119void 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 */
    143int 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 */
    165void 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