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/slab.h> 26 #include <asm/spu.h> 27 #include <asm/spu_csa.h> 28 #include "spufs.h" 29 30 struct spu_context *alloc_spu_context(struct address_space *local_store) 31 { 32 struct spu_context *ctx; 33 ctx = kmalloc(sizeof *ctx, GFP_KERNEL); 34 if (!ctx) 35 goto out; 36 /* Binding to physical processor deferred 37 * until spu_activate(). 38 */ 39 spu_init_csa(&ctx->csa); 40 if (!ctx->csa.lscsa) { 41 goto out_free; 42 } 43 spin_lock_init(&ctx->mmio_lock); 44 kref_init(&ctx->kref); 45 init_rwsem(&ctx->state_sema); 46 init_MUTEX(&ctx->run_sema); 47 init_waitqueue_head(&ctx->ibox_wq); 48 init_waitqueue_head(&ctx->wbox_wq); 49 init_waitqueue_head(&ctx->stop_wq); 50 ctx->ibox_fasync = NULL; 51 ctx->wbox_fasync = NULL; 52 ctx->state = SPU_STATE_SAVED; 53 ctx->local_store = local_store; 54 ctx->spu = NULL; 55 ctx->ops = &spu_backing_ops; 56 ctx->owner = get_task_mm(current); 57 goto out; 58 out_free: 59 kfree(ctx); 60 ctx = NULL; 61 out: 62 return ctx; 63 } 64 65 void destroy_spu_context(struct kref *kref) 66 { 67 struct spu_context *ctx; 68 ctx = container_of(kref, struct spu_context, kref); 69 down_write(&ctx->state_sema); 70 spu_deactivate(ctx); 71 ctx->ibox_fasync = NULL; 72 ctx->wbox_fasync = NULL; 73 up_write(&ctx->state_sema); 74 spu_fini_csa(&ctx->csa); 75 kfree(ctx); 76 } 77 78 struct spu_context * get_spu_context(struct spu_context *ctx) 79 { 80 kref_get(&ctx->kref); 81 return ctx; 82 } 83 84 int put_spu_context(struct spu_context *ctx) 85 { 86 return kref_put(&ctx->kref, &destroy_spu_context); 87 } 88 89 /* give up the mm reference when the context is about to be destroyed */ 90 void spu_forget(struct spu_context *ctx) 91 { 92 struct mm_struct *mm; 93 spu_acquire_saved(ctx); 94 mm = ctx->owner; 95 ctx->owner = NULL; 96 mmput(mm); 97 spu_release(ctx); 98 } 99 100 void spu_acquire(struct spu_context *ctx) 101 { 102 down_read(&ctx->state_sema); 103 } 104 105 void spu_release(struct spu_context *ctx) 106 { 107 up_read(&ctx->state_sema); 108 } 109 110 void spu_unmap_mappings(struct spu_context *ctx) 111 { 112 unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1); 113 } 114 115 int spu_acquire_runnable(struct spu_context *ctx) 116 { 117 int ret = 0; 118 119 down_read(&ctx->state_sema); 120 if (ctx->state == SPU_STATE_RUNNABLE) { 121 ctx->spu->prio = current->prio; 122 return 0; 123 } 124 up_read(&ctx->state_sema); 125 126 down_write(&ctx->state_sema); 127 /* ctx is about to be freed, can't acquire any more */ 128 if (!ctx->owner) { 129 ret = -EINVAL; 130 goto out; 131 } 132 133 if (ctx->state == SPU_STATE_SAVED) { 134 ret = spu_activate(ctx, 0); 135 if (ret) 136 goto out; 137 ctx->state = SPU_STATE_RUNNABLE; 138 } 139 140 downgrade_write(&ctx->state_sema); 141 /* On success, we return holding the lock */ 142 143 return ret; 144 out: 145 /* Release here, to simplify calling code. */ 146 up_write(&ctx->state_sema); 147 148 return ret; 149 } 150 151 void spu_acquire_saved(struct spu_context *ctx) 152 { 153 down_read(&ctx->state_sema); 154 155 if (ctx->state == SPU_STATE_SAVED) 156 return; 157 158 up_read(&ctx->state_sema); 159 down_write(&ctx->state_sema); 160 161 if (ctx->state == SPU_STATE_RUNNABLE) { 162 spu_deactivate(ctx); 163 ctx->state = SPU_STATE_SAVED; 164 } 165 166 downgrade_write(&ctx->state_sema); 167 } 168