Commit c6730ed4 authored by Jeremy Kerr's avatar Jeremy Kerr Committed by Paul Mackerras

[POWERPC] spufs: Load isolation kernel from spu_run

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: default avatarJeremy Kerr <jk@ozlabs.org>
Signed-off-by: default avatarArnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 3960c260
......@@ -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, },
{},
};
......@@ -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;
}
......
......@@ -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;
return ret;
}
static inline int spu_run_fini(struct spu_context *ctx, u32 * npc,
......
......@@ -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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