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