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Subject[PATCH 16/22] spufs: load isolation kernel from spu_run
From: Jeremy Kerr <jeremy@au1.ibm.com>
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 <jeremy@au1.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
---
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/file.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/file.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/file.c
@@ -1358,37 +1358,6 @@ static struct file_operations spufs_mfc_
.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_cont
{ "psmap", &spufs_psmap_fops, 0666, },
{ "phys-id", &spufs_id_ops, 0666, },
{ "object-id", &spufs_object_id_ops, 0666, },
- { "recycle", &spufs_recycle_fops, 0222, },
{},
};
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/inode.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/inode.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/inode.c
@@ -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_fop
.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 i
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: linux-2.6/arch/powerpc/platforms/cell/spufs/run.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/run.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/run.c
@@ -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
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: linux-2.6/arch/powerpc/platforms/cell/spufs/spufs.h
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/spufs.h
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -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
--

-
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