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(void) 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 init_waitqueue_head(&ctx->mfc_wq); 51 ctx->ibox_fasync = NULL; 52 ctx->wbox_fasync = NULL; 53 ctx->mfc_fasync = NULL; 54 ctx->mfc = NULL; 55 ctx->tagwait = 0; 56 ctx->state = SPU_STATE_SAVED; 57 ctx->local_store = NULL; 58 ctx->cntl = NULL; 59 ctx->signal1 = NULL; 60 ctx->signal2 = NULL; 61 ctx->spu = NULL; 62 ctx->ops = &spu_backing_ops; 63 ctx->owner = get_task_mm(current); 64 goto out; 65 out_free: 66 kfree(ctx); 67 ctx = NULL; 68 out: 69 return ctx; 70 } 71 72 void destroy_spu_context(struct kref *kref) 73 { 74 struct spu_context *ctx; 75 ctx = container_of(kref, struct spu_context, kref); 76 down_write(&ctx->state_sema); 77 spu_deactivate(ctx); 78 up_write(&ctx->state_sema); 79 spu_fini_csa(&ctx->csa); 80 kfree(ctx); 81 } 82 83 struct spu_context * get_spu_context(struct spu_context *ctx) 84 { 85 kref_get(&ctx->kref); 86 return ctx; 87 } 88 89 int put_spu_context(struct spu_context *ctx) 90 { 91 return kref_put(&ctx->kref, &destroy_spu_context); 92 } 93 94 /* give up the mm reference when the context is about to be destroyed */ 95 void spu_forget(struct spu_context *ctx) 96 { 97 struct mm_struct *mm; 98 spu_acquire_saved(ctx); 99 mm = ctx->owner; 100 ctx->owner = NULL; 101 mmput(mm); 102 spu_release(ctx); 103 } 104 105 void spu_acquire(struct spu_context *ctx) 106 { 107 down_read(&ctx->state_sema); 108 } 109 110 void spu_release(struct spu_context *ctx) 111 { 112 up_read(&ctx->state_sema); 113 } 114 115 void spu_unmap_mappings(struct spu_context *ctx) 116 { 117 if (ctx->local_store) 118 unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1); 119 if (ctx->mfc) 120 unmap_mapping_range(ctx->mfc, 0, 0x4000, 1); 121 if (ctx->cntl) 122 unmap_mapping_range(ctx->cntl, 0, 0x4000, 1); 123 if (ctx->signal1) 124 unmap_mapping_range(ctx->signal1, 0, 0x4000, 1); 125 if (ctx->signal2) 126 unmap_mapping_range(ctx->signal2, 0, 0x4000, 1); 127 } 128 129 int spu_acquire_runnable(struct spu_context *ctx) 130 { 131 int ret = 0; 132 133 down_read(&ctx->state_sema); 134 if (ctx->state == SPU_STATE_RUNNABLE) { 135 ctx->spu->prio = current->prio; 136 return 0; 137 } 138 up_read(&ctx->state_sema); 139 140 down_write(&ctx->state_sema); 141 /* ctx is about to be freed, can't acquire any more */ 142 if (!ctx->owner) { 143 ret = -EINVAL; 144 goto out; 145 } 146 147 if (ctx->state == SPU_STATE_SAVED) { 148 ret = spu_activate(ctx, 0); 149 if (ret) 150 goto out; 151 ctx->state = SPU_STATE_RUNNABLE; 152 } 153 154 downgrade_write(&ctx->state_sema); 155 /* On success, we return holding the lock */ 156 157 return ret; 158 out: 159 /* Release here, to simplify calling code. */ 160 up_write(&ctx->state_sema); 161 162 return ret; 163 } 164 165 void spu_acquire_saved(struct spu_context *ctx) 166 { 167 down_read(&ctx->state_sema); 168 169 if (ctx->state == SPU_STATE_SAVED) 170 return; 171 172 up_read(&ctx->state_sema); 173 down_write(&ctx->state_sema); 174 175 if (ctx->state == SPU_STATE_RUNNABLE) { 176 spu_deactivate(ctx); 177 ctx->state = SPU_STATE_SAVED; 178 } 179 180 downgrade_write(&ctx->state_sema); 181 } 182