[POWERPC] spufs: Load isolation kernel from spu_run
authorJeremy Kerr <jk@ozlabs.org>
Mon, 20 Nov 2006 17:45:10 +0000 (18:45 +0100)
committerPaul Mackerras <paulus@samba.org>
Mon, 4 Dec 2006 09:40:06 +0000 (20:40 +1100)
In order to fit with the "don't-run-spus-outside-of-spu_run" model, this
patch starts the isolated-mode loader in spu_run, rather than
spu_create. If spu_run is passed an isolated-mode context that isn't in
isolated mode state, it will run the loader.

This fixes potential races with the isolated SPE app doing a
stop-and-signal before the PPE has called spu_run: bugzilla #29111.
Also (in conjunction with a mambo patch), this addresses #28565, as we
always set the runcntrl register when entering spu_run.

It is up to libspe to ensure that isolated-mode apps are cleaned up
after running to completion - ie, put the app through the "ISOLATE EXIT"
state (see Ch11 of the CBEA).

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
arch/powerpc/platforms/cell/spufs/file.c
arch/powerpc/platforms/cell/spufs/inode.c
arch/powerpc/platforms/cell/spufs/run.c
arch/powerpc/platforms/cell/spufs/spufs.h

index e6667530332b3961dbc89a6dc6bffbb4545e55f7..50e0afc46ad25c691f11691a480401f352227404 100644 (file)
@@ -1358,37 +1358,6 @@ static struct file_operations spufs_mfc_fops = {
        .mmap    = spufs_mfc_mmap,
 };
 
-
-static int spufs_recycle_open(struct inode *inode, struct file *file)
-{
-       file->private_data = SPUFS_I(inode)->i_ctx;
-       return nonseekable_open(inode, file);
-}
-
-static ssize_t spufs_recycle_write(struct file *file,
-               const char __user *buffer, size_t size, loff_t *pos)
-{
-       struct spu_context *ctx = file->private_data;
-       int ret;
-
-       if (!(ctx->flags & SPU_CREATE_ISOLATE))
-               return -EINVAL;
-
-       if (size < 1)
-               return -EINVAL;
-
-       ret = spu_recycle_isolated(ctx);
-
-       if (ret)
-               return ret;
-       return size;
-}
-
-static struct file_operations spufs_recycle_fops = {
-       .open    = spufs_recycle_open,
-       .write   = spufs_recycle_write,
-};
-
 static void spufs_npc_set(void *data, u64 val)
 {
        struct spu_context *ctx = data;
@@ -1789,6 +1758,5 @@ struct tree_descr spufs_dir_nosched_contents[] = {
        { "psmap", &spufs_psmap_fops, 0666, },
        { "phys-id", &spufs_id_ops, 0666, },
        { "object-id", &spufs_object_id_ops, 0666, },
-       { "recycle", &spufs_recycle_fops, 0222, },
        {},
 };
index 1fbcc53692434764899db7d51e94f35975a5b071..d5f0a21a19d8cc3d5427ca63b5991e3a915bdfab 100644 (file)
@@ -34,8 +34,6 @@
 #include <linux/parser.h>
 
 #include <asm/prom.h>
-#include <asm/spu_priv1.h>
-#include <asm/io.h>
 #include <asm/semaphore.h>
 #include <asm/spu.h>
 #include <asm/uaccess.h>
@@ -43,7 +41,7 @@
 #include "spufs.h"
 
 static kmem_cache_t *spufs_inode_cache;
-static char *isolated_loader;
+char *isolated_loader;
 
 static struct inode *
 spufs_alloc_inode(struct super_block *sb)
@@ -235,102 +233,6 @@ struct file_operations spufs_context_fops = {
        .fsync          = simple_sync_file,
 };
 
-static int spu_setup_isolated(struct spu_context *ctx)
-{
-       int ret;
-       u64 __iomem *mfc_cntl;
-       u64 sr1;
-       u32 status;
-       unsigned long timeout;
-       const u32 status_loading = SPU_STATUS_RUNNING
-               | SPU_STATUS_ISOLATED_STATE | SPU_STATUS_ISOLATED_LOAD_STATUS;
-
-       if (!isolated_loader)
-               return -ENODEV;
-
-       /* prevent concurrent operation with spu_run */
-       down(&ctx->run_sema);
-       ctx->ops->master_start(ctx);
-
-       ret = spu_acquire_exclusive(ctx);
-       if (ret)
-               goto out;
-
-       mfc_cntl = &ctx->spu->priv2->mfc_control_RW;
-
-       /* purge the MFC DMA queue to ensure no spurious accesses before we
-        * enter kernel mode */
-       timeout = jiffies + HZ;
-       out_be64(mfc_cntl, MFC_CNTL_PURGE_DMA_REQUEST);
-       while ((in_be64(mfc_cntl) & MFC_CNTL_PURGE_DMA_STATUS_MASK)
-                       != MFC_CNTL_PURGE_DMA_COMPLETE) {
-               if (time_after(jiffies, timeout)) {
-                       printk(KERN_ERR "%s: timeout flushing MFC DMA queue\n",
-                                       __FUNCTION__);
-                       ret = -EIO;
-                       goto out_unlock;
-               }
-               cond_resched();
-       }
-
-       /* put the SPE in kernel mode to allow access to the loader */
-       sr1 = spu_mfc_sr1_get(ctx->spu);
-       sr1 &= ~MFC_STATE1_PROBLEM_STATE_MASK;
-       spu_mfc_sr1_set(ctx->spu, sr1);
-
-       /* start the loader */
-       ctx->ops->signal1_write(ctx, (unsigned long)isolated_loader >> 32);
-       ctx->ops->signal2_write(ctx,
-                       (unsigned long)isolated_loader & 0xffffffff);
-
-       ctx->ops->runcntl_write(ctx,
-                       SPU_RUNCNTL_RUNNABLE | SPU_RUNCNTL_ISOLATE);
-
-       ret = 0;
-       timeout = jiffies + HZ;
-       while (((status = ctx->ops->status_read(ctx)) & status_loading) ==
-                               status_loading) {
-               if (time_after(jiffies, timeout)) {
-                       printk(KERN_ERR "%s: timeout waiting for loader\n",
-                                       __FUNCTION__);
-                       ret = -EIO;
-                       goto out_drop_priv;
-               }
-               cond_resched();
-       }
-
-       if (!(status & SPU_STATUS_RUNNING)) {
-               /* If isolated LOAD has failed: run SPU, we will get a stop-and
-                * signal later. */
-               pr_debug("%s: isolated LOAD failed\n", __FUNCTION__);
-               ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);
-               ret = -EACCES;
-
-       } else if (!(status & SPU_STATUS_ISOLATED_STATE)) {
-               /* This isn't allowed by the CBEA, but check anyway */
-               pr_debug("%s: SPU fell out of isolated mode?\n", __FUNCTION__);
-               ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_STOP);
-               ret = -EINVAL;
-       }
-
-out_drop_priv:
-       /* Finished accessing the loader. Drop kernel mode */
-       sr1 |= MFC_STATE1_PROBLEM_STATE_MASK;
-       spu_mfc_sr1_set(ctx->spu, sr1);
-
-out_unlock:
-       spu_release_exclusive(ctx);
-out:
-       ctx->ops->master_stop(ctx);
-       up(&ctx->run_sema);
-       return ret;
-}
-
-int spu_recycle_isolated(struct spu_context *ctx)
-{
-       return spu_setup_isolated(ctx);
-}
-
 static int
 spufs_mkdir(struct inode *dir, struct dentry *dentry, unsigned int flags,
                int mode)
@@ -439,15 +341,6 @@ static int spufs_create_context(struct inode *inode,
 out_unlock:
        mutex_unlock(&inode->i_mutex);
 out:
-       if (ret >= 0 && (flags & SPU_CREATE_ISOLATE)) {
-               int setup_err = spu_setup_isolated(
-                               SPUFS_I(dentry->d_inode)->i_ctx);
-               /* FIXME: clean up context again on failure to avoid
-                         leak. */
-               if (setup_err)
-                       ret = setup_err;
-       }
-
        dput(dentry);
        return ret;
 }
index 212b9c2f04ab82480af58b01c2a5f8a02db2fc65..1be4e3339d8e170275ea183f6122bdeb13dacdc0 100644 (file)
@@ -4,6 +4,8 @@
 #include <linux/ptrace.h>
 
 #include <asm/spu.h>
+#include <asm/spu_priv1.h>
+#include <asm/io.h>
 #include <asm/unistd.h>
 
 #include "spufs.h"
@@ -51,21 +53,122 @@ static inline int spu_stopped(struct spu_context *ctx, u32 * stat)
        return (!(*stat & 0x1) || pte_fault || spu->class_0_pending) ? 1 : 0;
 }
 
+static int spu_setup_isolated(struct spu_context *ctx)
+{
+       int ret;
+       u64 __iomem *mfc_cntl;
+       u64 sr1;
+       u32 status;
+       unsigned long timeout;
+       const u32 status_loading = SPU_STATUS_RUNNING
+               | SPU_STATUS_ISOLATED_STATE | SPU_STATUS_ISOLATED_LOAD_STATUS;
+
+       if (!isolated_loader)
+               return -ENODEV;
+
+       ret = spu_acquire_exclusive(ctx);
+       if (ret)
+               goto out;
+
+       mfc_cntl = &ctx->spu->priv2->mfc_control_RW;
+
+       /* purge the MFC DMA queue to ensure no spurious accesses before we
+        * enter kernel mode */
+       timeout = jiffies + HZ;
+       out_be64(mfc_cntl, MFC_CNTL_PURGE_DMA_REQUEST);
+       while ((in_be64(mfc_cntl) & MFC_CNTL_PURGE_DMA_STATUS_MASK)
+                       != MFC_CNTL_PURGE_DMA_COMPLETE) {
+               if (time_after(jiffies, timeout)) {
+                       printk(KERN_ERR "%s: timeout flushing MFC DMA queue\n",
+                                       __FUNCTION__);
+                       ret = -EIO;
+                       goto out_unlock;
+               }
+               cond_resched();
+       }
+
+       /* put the SPE in kernel mode to allow access to the loader */
+       sr1 = spu_mfc_sr1_get(ctx->spu);
+       sr1 &= ~MFC_STATE1_PROBLEM_STATE_MASK;
+       spu_mfc_sr1_set(ctx->spu, sr1);
+
+       /* start the loader */
+       ctx->ops->signal1_write(ctx, (unsigned long)isolated_loader >> 32);
+       ctx->ops->signal2_write(ctx,
+                       (unsigned long)isolated_loader & 0xffffffff);
+
+       ctx->ops->runcntl_write(ctx,
+                       SPU_RUNCNTL_RUNNABLE | SPU_RUNCNTL_ISOLATE);
+
+       ret = 0;
+       timeout = jiffies + HZ;
+       while (((status = ctx->ops->status_read(ctx)) & status_loading) ==
+                               status_loading) {
+               if (time_after(jiffies, timeout)) {
+                       printk(KERN_ERR "%s: timeout waiting for loader\n",
+                                       __FUNCTION__);
+                       ret = -EIO;
+                       goto out_drop_priv;
+               }
+               cond_resched();
+       }
+
+       if (!(status & SPU_STATUS_RUNNING)) {
+               /* If isolated LOAD has failed: run SPU, we will get a stop-and
+                * signal later. */
+               pr_debug("%s: isolated LOAD failed\n", __FUNCTION__);
+               ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);
+               ret = -EACCES;
+
+       } else if (!(status & SPU_STATUS_ISOLATED_STATE)) {
+               /* This isn't allowed by the CBEA, but check anyway */
+               pr_debug("%s: SPU fell out of isolated mode?\n", __FUNCTION__);
+               ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_STOP);
+               ret = -EINVAL;
+       }
+
+out_drop_priv:
+       /* Finished accessing the loader. Drop kernel mode */
+       sr1 |= MFC_STATE1_PROBLEM_STATE_MASK;
+       spu_mfc_sr1_set(ctx->spu, sr1);
+
+out_unlock:
+       spu_release_exclusive(ctx);
+out:
+       return ret;
+}
+
 static inline int spu_run_init(struct spu_context *ctx, u32 * npc)
 {
        int ret;
        unsigned long runcntl = SPU_RUNCNTL_RUNNABLE;
 
-       if ((ret = spu_acquire_runnable(ctx)) != 0)
+       ret = spu_acquire_runnable(ctx);
+       if (ret)
                return ret;
 
-       /* if we're in isolated mode, we would have started the SPU
-        * earlier, so don't do it again now. */
-       if (!(ctx->flags & SPU_CREATE_ISOLATE)) {
+       if (ctx->flags & SPU_CREATE_ISOLATE) {
+               if (!(ctx->ops->status_read(ctx) & SPU_STATUS_ISOLATED_STATE)) {
+                       /* Need to release ctx, because spu_setup_isolated will
+                        * acquire it exclusively.
+                        */
+                       spu_release(ctx);
+                       ret = spu_setup_isolated(ctx);
+                       if (!ret)
+                               ret = spu_acquire_runnable(ctx);
+               }
+
+               /* if userspace has set the runcntrl register (eg, to issue an
+                * isolated exit), we need to re-set it here */
+               runcntl = ctx->ops->runcntl_read(ctx) &
+                       (SPU_RUNCNTL_RUNNABLE | SPU_RUNCNTL_ISOLATE);
+               if (runcntl == 0)
+                       runcntl = SPU_RUNCNTL_RUNNABLE;
+       } else
                ctx->ops->npc_write(ctx, *npc);
-               ctx->ops->runcntl_write(ctx, runcntl);
-       }
-       return 0;
+
+       ctx->ops->runcntl_write(ctx, runcntl);
+       return ret;
 }
 
 static inline int spu_run_fini(struct spu_context *ctx, u32 * npc,
index ca56b9b11c1d22196e52b72b9b00e43fca15d318..23d20f38056015dd9bb8f5a20d236b10a03272f2 100644 (file)
@@ -183,7 +183,8 @@ void spu_yield(struct spu_context *ctx);
 int __init spu_sched_init(void);
 void __exit spu_sched_exit(void);
 
-int spu_recycle_isolated(struct spu_context *ctx);
+extern char *isolated_loader;
+
 /*
  * spufs_wait
  *     Same as wait_event_interruptible(), except that here