[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: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c
index 212b9c2..1be4e33 100644
--- a/arch/powerpc/platforms/cell/spufs/run.c
+++ b/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 @@
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,