[linux-2.6-block.git] / arch / powerpc / platforms / cell / spufs / run.c

#define DEBUG

#include <linux/wait.h>
#include <linux/ptrace.h>

#include <asm/spu.h>
#include <asm/spu_priv1.h>
#include <asm/io.h>
#include <asm/unistd.h>

#include "spufs.h"

/* interrupt-level stop callback function. */
void spufs_stop_callback(struct spu *spu)
{
	struct spu_context *ctx = spu->ctx;

	/*
	 * It should be impossible to preempt a context while an exception
	 * is being processed, since the context switch code is specially
	 * coded to deal with interrupts ... But, just in case, sanity check
	 * the context pointer.  It is OK to return doing nothing since
	 * the exception will be regenerated when the context is resumed.
	 */
	if (ctx) {
		/* Copy exception arguments into module specific structure */
		ctx->csa.class_0_pending = spu->class_0_pending;
		ctx->csa.dsisr = spu->dsisr;
		ctx->csa.dar = spu->dar;

		/* ensure that the exception status has hit memory before a
		 * thread waiting on the context's stop queue is woken */
		smp_wmb();

		wake_up_all(&ctx->stop_wq);
	}

	/* Clear callback arguments from spu structure */
	spu->class_0_pending = 0;
	spu->dsisr = 0;
	spu->dar = 0;
}

int spu_stopped(struct spu_context *ctx, u32 *stat)
{
	u64 dsisr;
	u32 stopped;

	*stat = ctx->ops->status_read(ctx);

	if (test_bit(SPU_SCHED_NOTIFY_ACTIVE, &ctx->sched_flags))
		return 1;

	stopped = SPU_STATUS_INVALID_INSTR | SPU_STATUS_SINGLE_STEP |
		SPU_STATUS_STOPPED_BY_HALT | SPU_STATUS_STOPPED_BY_STOP;
	if (!(*stat & SPU_STATUS_RUNNING) && (*stat & stopped))
		return 1;

	dsisr = ctx->csa.dsisr;
	if (dsisr & (MFC_DSISR_PTE_NOT_FOUND | MFC_DSISR_ACCESS_DENIED))
		return 1;

	if (ctx->csa.class_0_pending)
		return 1;

	return 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;

	ret = -ENODEV;
	if (!isolated_loader)
		goto out;

	/*
	 * We need to exclude userspace access to the context.
	 *
	 * To protect against memory access we invalidate all ptes
	 * and make sure the pagefault handlers block on the mutex.
	 */
	spu_unmap_mappings(ctx);

	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",
					__func__);
			ret = -EIO;
			goto out;
		}
		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",
					__func__);
			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", __func__);
		ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);
		ret = -EACCES;
		goto out_drop_priv;
	}

	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", __func__);
		ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_STOP);
		ret = -EINVAL;
		goto out_drop_priv;
	}

out_drop_priv:
	/* Finished accessing the loader. Drop kernel mode */
	sr1 |= MFC_STATE1_PROBLEM_STATE_MASK;
	spu_mfc_sr1_set(ctx->spu, sr1);

out:
	return ret;
}

static int spu_run_init(struct spu_context *ctx, u32 *npc)
{
	unsigned long runcntl = SPU_RUNCNTL_RUNNABLE;
	int ret;

	spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);

	/*
	 * NOSCHED is synchronous scheduling with respect to the caller.
	 * The caller waits for the context to be loaded.
	 */
	if (ctx->flags & SPU_CREATE_NOSCHED) {
		if (ctx->state == SPU_STATE_SAVED) {
			ret = spu_activate(ctx, 0);
			if (ret)
				return ret;
		}
	}

	/*
	 * Apply special setup as required.
	 */
	if (ctx->flags & SPU_CREATE_ISOLATE) {
		if (!(ctx->ops->status_read(ctx) & SPU_STATUS_ISOLATED_STATE)) {
			ret = spu_setup_isolated(ctx);
			if (ret)
				return ret;
		}

		/*
		 * 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;
	}

	if (ctx->flags & SPU_CREATE_NOSCHED) {
		spuctx_switch_state(ctx, SPU_UTIL_USER);
		ctx->ops->runcntl_write(ctx, runcntl);
	} else {
		unsigned long privcntl;

		if (test_thread_flag(TIF_SINGLESTEP))
			privcntl = SPU_PRIVCNTL_MODE_SINGLE_STEP;
		else
			privcntl = SPU_PRIVCNTL_MODE_NORMAL;

		ctx->ops->npc_write(ctx, *npc);
		ctx->ops->privcntl_write(ctx, privcntl);
		ctx->ops->runcntl_write(ctx, runcntl);

		if (ctx->state == SPU_STATE_SAVED) {
			ret = spu_activate(ctx, 0);
			if (ret)
				return ret;
		} else {
			spuctx_switch_state(ctx, SPU_UTIL_USER);
		}
	}

	set_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags);
	return 0;
}

static int spu_run_fini(struct spu_context *ctx, u32 *npc,
			       u32 *status)
{
	int ret = 0;

	spu_del_from_rq(ctx);

	*status = ctx->ops->status_read(ctx);
	*npc = ctx->ops->npc_read(ctx);

	spuctx_switch_state(ctx, SPU_UTIL_IDLE_LOADED);
	clear_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags);
	spu_release(ctx);

	if (signal_pending(current))
		ret = -ERESTARTSYS;

	return ret;
}

/*
 * SPU syscall restarting is tricky because we violate the basic
 * assumption that the signal handler is running on the interrupted
 * thread. Here instead, the handler runs on PowerPC user space code,
 * while the syscall was called from the SPU.
 * This means we can only do a very rough approximation of POSIX
 * signal semantics.
 */
static int spu_handle_restartsys(struct spu_context *ctx, long *spu_ret,
			  unsigned int *npc)
{
	int ret;

	switch (*spu_ret) {
	case -ERESTARTSYS:
	case -ERESTARTNOINTR:
		/*
		 * Enter the regular syscall restarting for
		 * sys_spu_run, then restart the SPU syscall
		 * callback.
		 */
		*npc -= 8;
		ret = -ERESTARTSYS;
		break;
	case -ERESTARTNOHAND:
	case -ERESTART_RESTARTBLOCK:
		/*
		 * Restart block is too hard for now, just return -EINTR
		 * to the SPU.
		 * ERESTARTNOHAND comes from sys_pause, we also return
		 * -EINTR from there.
		 * Assume that we need to be restarted ourselves though.
		 */
		*spu_ret = -EINTR;
		ret = -ERESTARTSYS;
		break;
	default:
		printk(KERN_WARNING "%s: unexpected return code %ld\n",
			__func__, *spu_ret);
		ret = 0;
	}
	return ret;
}

static int spu_process_callback(struct spu_context *ctx)
{
	struct spu_syscall_block s;
	u32 ls_pointer, npc;
	void __iomem *ls;
	long spu_ret;
	int ret, ret2;

	/* get syscall block from local store */
	npc = ctx->ops->npc_read(ctx) & ~3;
	ls = (void __iomem *)ctx->ops->get_ls(ctx);
	ls_pointer = in_be32(ls + npc);
	if (ls_pointer > (LS_SIZE - sizeof(s)))
		return -EFAULT;
	memcpy_fromio(&s, ls + ls_pointer, sizeof(s));

	/* do actual syscall without pinning the spu */
	ret = 0;
	spu_ret = -ENOSYS;
	npc += 4;

	if (s.nr_ret < __NR_syscalls) {
		spu_release(ctx);
		/* do actual system call from here */
		spu_ret = spu_sys_callback(&s);
		if (spu_ret <= -ERESTARTSYS) {
			ret = spu_handle_restartsys(ctx, &spu_ret, &npc);
		}
		ret2 = spu_acquire(ctx);
		if (ret == -ERESTARTSYS)
			return ret;
		if (ret2)
			return -EINTR;
	}

	/* need to re-get the ls, as it may have changed when we released the
	 * spu */
	ls = (void __iomem *)ctx->ops->get_ls(ctx);

	/* write result, jump over indirect pointer */
	memcpy_toio(ls + ls_pointer, &spu_ret, sizeof(spu_ret));
	ctx->ops->npc_write(ctx, npc);
	ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);
	return ret;
}

long spufs_run_spu(struct spu_context *ctx, u32 *npc, u32 *event)
{
	int ret;
	struct spu *spu;
	u32 status;

	if (mutex_lock_interruptible(&ctx->run_mutex))
		return -ERESTARTSYS;

	spu_enable_spu(ctx);
	ctx->event_return = 0;

	ret = spu_acquire(ctx);
	if (ret)
		goto out_unlock;

	spu_update_sched_info(ctx);

	ret = spu_run_init(ctx, npc);
	if (ret) {
		spu_release(ctx);
		goto out;
	}

	do {
		ret = spufs_wait(ctx->stop_wq, spu_stopped(ctx, &status));
		if (unlikely(ret)) {
			/*
			 * This is nasty: we need the state_mutex for all the
			 * bookkeeping even if the syscall was interrupted by
			 * a signal. ewww.
			 */
			mutex_lock(&ctx->state_mutex);
			break;
		}
		spu = ctx->spu;
		if (unlikely(test_and_clear_bit(SPU_SCHED_NOTIFY_ACTIVE,
						&ctx->sched_flags))) {
			if (!(status & SPU_STATUS_STOPPED_BY_STOP)) {
				spu_switch_notify(spu, ctx);
				continue;
			}
		}

		spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);

		if ((status & SPU_STATUS_STOPPED_BY_STOP) &&
		    (status >> SPU_STOP_STATUS_SHIFT == 0x2104)) {
			ret = spu_process_callback(ctx);
			if (ret)
				break;
			status &= ~SPU_STATUS_STOPPED_BY_STOP;
		}
		ret = spufs_handle_class1(ctx);
		if (ret)
			break;

		ret = spufs_handle_class0(ctx);
		if (ret)
			break;

		if (signal_pending(current))
			ret = -ERESTARTSYS;
	} while (!ret && !(status & (SPU_STATUS_STOPPED_BY_STOP |
				      SPU_STATUS_STOPPED_BY_HALT |
				       SPU_STATUS_SINGLE_STEP)));

	spu_disable_spu(ctx);
	ret = spu_run_fini(ctx, npc, &status);
	spu_yield(ctx);

	spu_switch_log_notify(NULL, ctx, SWITCH_LOG_EXIT, status);

	if ((status & SPU_STATUS_STOPPED_BY_STOP) &&
	    (((status >> SPU_STOP_STATUS_SHIFT) & 0x3f00) == 0x2100))
		ctx->stats.libassist++;

	if ((ret == 0) ||
	    ((ret == -ERESTARTSYS) &&
	     ((status & SPU_STATUS_STOPPED_BY_HALT) ||
	      (status & SPU_STATUS_SINGLE_STEP) ||
	      ((status & SPU_STATUS_STOPPED_BY_STOP) &&
	       (status >> SPU_STOP_STATUS_SHIFT != 0x2104)))))
		ret = status;

	/* Note: we don't need to force_sig SIGTRAP on single-step
	 * since we have TIF_SINGLESTEP set, thus the kernel will do
	 * it upon return from the syscall anyawy
	 */
	if (unlikely(status & SPU_STATUS_SINGLE_STEP))
		ret = -ERESTARTSYS;

	else if (unlikely((status & SPU_STATUS_STOPPED_BY_STOP)
	    && (status >> SPU_STOP_STATUS_SHIFT) == 0x3fff)) {
		force_sig(SIGTRAP, current);
		ret = -ERESTARTSYS;
	}

out:
	*event = ctx->event_return;
out_unlock:
	mutex_unlock(&ctx->run_mutex);
	return ret;
}
Commit	Line	Data
0afacde3	1	#define DEBUG
0afacde3	2
ce8ab854 AB	3	#include <linux/wait.h>
	4	#include <linux/ptrace.h>
	5
	6	#include <asm/spu.h>
c6730ed4 JK	7	#include <asm/spu_priv1.h>
c6730ed4 JK	8	#include <asm/io.h>
cfff5b23	9	#include <asm/unistd.h>
ce8ab854 AB	10
	11	#include "spufs.h"
	12
	13	/* interrupt-level stop callback function. */
	14	void spufs_stop_callback(struct spu *spu)
	15	{
	16	struct spu_context *ctx = spu->ctx;
	17
d6ad39bc JK	18	/*
	19	* It should be impossible to preempt a context while an exception
	20	* is being processed, since the context switch code is specially
	21	* coded to deal with interrupts ... But, just in case, sanity check
	22	* the context pointer. It is OK to return doing nothing since
	23	* the exception will be regenerated when the context is resumed.
	24	*/
	25	if (ctx) {
	26	/* Copy exception arguments into module specific structure */
	27	ctx->csa.class_0_pending = spu->class_0_pending;
	28	ctx->csa.dsisr = spu->dsisr;
	29	ctx->csa.dar = spu->dar;
	30
	31	/* ensure that the exception status has hit memory before a
	32	* thread waiting on the context's stop queue is woken */
	33	smp_wmb();
	34
	35	wake_up_all(&ctx->stop_wq);
	36	}
	37
	38	/* Clear callback arguments from spu structure */
	39	spu->class_0_pending = 0;
	40	spu->dsisr = 0;
	41	spu->dar = 0;
ce8ab854 AB	42	}
ce8ab854 AB	43
e65c2f6f	44	int spu_stopped(struct spu_context ctx, u32 stat)
ce8ab854	45	{
e65c2f6f LB	46	u64 dsisr;
e65c2f6f LB	47	u32 stopped;
ce8ab854 AB	48
ce8ab854 AB	49	*stat = ctx->ops->status_read(ctx);
36aaccc1	50
e65c2f6f LB	51	if (test_bit(SPU_SCHED_NOTIFY_ACTIVE, &ctx->sched_flags))
	52	return 1;
	53
	54	stopped = SPU_STATUS_INVALID_INSTR \| SPU_STATUS_SINGLE_STEP \|
	55	SPU_STATUS_STOPPED_BY_HALT \| SPU_STATUS_STOPPED_BY_STOP;
85687ff2	56	if (!(stat & SPU_STATUS_RUNNING) && (stat & stopped))
e65c2f6f LB	57	return 1;
	58
	59	dsisr = ctx->csa.dsisr;
	60	if (dsisr & (MFC_DSISR_PTE_NOT_FOUND \| MFC_DSISR_ACCESS_DENIED))
36aaccc1	61	return 1;
e65c2f6f LB	62
	63	if (ctx->csa.class_0_pending)
	64	return 1;
	65
	66	return 0;
ce8ab854 AB	67	}
ce8ab854 AB	68
c6730ed4 JK	69	static int spu_setup_isolated(struct spu_context *ctx)
	70	{
	71	int ret;
	72	u64 __iomem *mfc_cntl;
	73	u64 sr1;
	74	u32 status;
	75	unsigned long timeout;
	76	const u32 status_loading = SPU_STATUS_RUNNING
	77	\| SPU_STATUS_ISOLATED_STATE \| SPU_STATUS_ISOLATED_LOAD_STATUS;
	78
7ec18ab9	79	ret = -ENODEV;
c6730ed4	80	if (!isolated_loader)
c6730ed4 JK	81	goto out;
c6730ed4 JK	82
7ec18ab9 CH	83	/*
	84	* We need to exclude userspace access to the context.
	85	*
	86	* To protect against memory access we invalidate all ptes
	87	* and make sure the pagefault handlers block on the mutex.
	88	*/
	89	spu_unmap_mappings(ctx);
	90
c6730ed4 JK	91	mfc_cntl = &ctx->spu->priv2->mfc_control_RW;
	92
	93	/* purge the MFC DMA queue to ensure no spurious accesses before we
	94	* enter kernel mode */
	95	timeout = jiffies + HZ;
	96	out_be64(mfc_cntl, MFC_CNTL_PURGE_DMA_REQUEST);
	97	while ((in_be64(mfc_cntl) & MFC_CNTL_PURGE_DMA_STATUS_MASK)
	98	!= MFC_CNTL_PURGE_DMA_COMPLETE) {
	99	if (time_after(jiffies, timeout)) {
	100	printk(KERN_ERR "%s: timeout flushing MFC DMA queue\n",
e48b1b45	101	__func__);
c6730ed4	102	ret = -EIO;
7ec18ab9	103	goto out;
c6730ed4 JK	104	}
	105	cond_resched();
	106	}
	107
	108	/* put the SPE in kernel mode to allow access to the loader */
	109	sr1 = spu_mfc_sr1_get(ctx->spu);
	110	sr1 &= ~MFC_STATE1_PROBLEM_STATE_MASK;
	111	spu_mfc_sr1_set(ctx->spu, sr1);
	112
	113	/* start the loader */
	114	ctx->ops->signal1_write(ctx, (unsigned long)isolated_loader >> 32);
	115	ctx->ops->signal2_write(ctx,
	116	(unsigned long)isolated_loader & 0xffffffff);
	117
	118	ctx->ops->runcntl_write(ctx,
	119	SPU_RUNCNTL_RUNNABLE \| SPU_RUNCNTL_ISOLATE);
	120
	121	ret = 0;
	122	timeout = jiffies + HZ;
	123	while (((status = ctx->ops->status_read(ctx)) & status_loading) ==
	124	status_loading) {
	125	if (time_after(jiffies, timeout)) {
	126	printk(KERN_ERR "%s: timeout waiting for loader\n",
e48b1b45	127	__func__);
c6730ed4 JK	128	ret = -EIO;
	129	goto out_drop_priv;
	130	}
	131	cond_resched();
	132	}
	133
	134	if (!(status & SPU_STATUS_RUNNING)) {
	135	/* If isolated LOAD has failed: run SPU, we will get a stop-and
	136	* signal later. */
e48b1b45	137	pr_debug("%s: isolated LOAD failed\n", __func__);
c6730ed4 JK	138	ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);
c6730ed4 JK	139	ret = -EACCES;
7ec18ab9 CH	140	goto out_drop_priv;
7ec18ab9 CH	141	}
c6730ed4	142
7ec18ab9	143	if (!(status & SPU_STATUS_ISOLATED_STATE)) {
c6730ed4	144	/* This isn't allowed by the CBEA, but check anyway */
e48b1b45	145	pr_debug("%s: SPU fell out of isolated mode?\n", __func__);
c6730ed4 JK	146	ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_STOP);
c6730ed4 JK	147	ret = -EINVAL;
7ec18ab9	148	goto out_drop_priv;
c6730ed4 JK	149	}
	150
	151	out_drop_priv:
	152	/* Finished accessing the loader. Drop kernel mode */
	153	sr1 \|= MFC_STATE1_PROBLEM_STATE_MASK;
	154	spu_mfc_sr1_set(ctx->spu, sr1);
	155
c6730ed4 JK	156	out:
	157	return ret;
	158	}
	159
36aaccc1	160	static int spu_run_init(struct spu_context ctx, u32 npc)
ce8ab854	161	{
e65c2f6f	162	unsigned long runcntl = SPU_RUNCNTL_RUNNABLE;
91569531	163	int ret;
cc210b3e	164
27ec41d3 AD	165	spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
27ec41d3 AD	166
e65c2f6f LB	167	/*
	168	* NOSCHED is synchronous scheduling with respect to the caller.
	169	* The caller waits for the context to be loaded.
	170	*/
	171	if (ctx->flags & SPU_CREATE_NOSCHED) {
91569531	172	if (ctx->state == SPU_STATE_SAVED) {
91569531 LB	173	ret = spu_activate(ctx, 0);
	174	if (ret)
	175	return ret;
	176	}
e65c2f6f	177	}
aa45e256	178
e65c2f6f LB	179	/*
	180	* Apply special setup as required.
	181	*/
	182	if (ctx->flags & SPU_CREATE_ISOLATE) {
c6730ed4	183	if (!(ctx->ops->status_read(ctx) & SPU_STATUS_ISOLATED_STATE)) {
91569531	184	ret = spu_setup_isolated(ctx);
7ec18ab9	185	if (ret)
aa45e256	186	return ret;
c6730ed4 JK	187	}
c6730ed4 JK	188
91569531 LB	189	/*
	190	* If userspace has set the runcntrl register (eg, to
	191	* issue an isolated exit), we need to re-set it here
	192	*/
c6730ed4 JK	193	runcntl = ctx->ops->runcntl_read(ctx) &
	194	(SPU_RUNCNTL_RUNNABLE \| SPU_RUNCNTL_ISOLATE);
	195	if (runcntl == 0)
	196	runcntl = SPU_RUNCNTL_RUNNABLE;
e65c2f6f	197	}
91569531	198
e65c2f6f	199	if (ctx->flags & SPU_CREATE_NOSCHED) {
91569531 LB	200	spuctx_switch_state(ctx, SPU_UTIL_USER);
91569531 LB	201	ctx->ops->runcntl_write(ctx, runcntl);
2eb1b120	202	} else {
cc210b3e LB	203	unsigned long privcntl;
cc210b3e LB	204
05169237	205	if (test_thread_flag(TIF_SINGLESTEP))
cc210b3e LB	206	privcntl = SPU_PRIVCNTL_MODE_SINGLE_STEP;
	207	else
	208	privcntl = SPU_PRIVCNTL_MODE_NORMAL;
cc210b3e LB	209
	210	ctx->ops->npc_write(ctx, *npc);
	211	ctx->ops->privcntl_write(ctx, privcntl);
e65c2f6f	212	ctx->ops->runcntl_write(ctx, runcntl);
c6730ed4	213
91569531	214	if (ctx->state == SPU_STATE_SAVED) {
91569531 LB	215	ret = spu_activate(ctx, 0);
	216	if (ret)
	217	return ret;
e65c2f6f LB	218	} else {
e65c2f6f LB	219	spuctx_switch_state(ctx, SPU_UTIL_USER);
91569531	220	}
91569531	221	}
27ec41d3	222
ce7c191b	223	set_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags);
aa45e256	224	return 0;
ce8ab854 AB	225	}
ce8ab854 AB	226
36aaccc1 BN	227	static int spu_run_fini(struct spu_context ctx, u32 npc,
36aaccc1 BN	228	u32 *status)
ce8ab854 AB	229	{
	230	int ret = 0;
	231
e65c2f6f LB	232	spu_del_from_rq(ctx);
e65c2f6f LB	233
ce8ab854 AB	234	*status = ctx->ops->status_read(ctx);
ce8ab854 AB	235	*npc = ctx->ops->npc_read(ctx);
27ec41d3 AD	236
27ec41d3 AD	237	spuctx_switch_state(ctx, SPU_UTIL_IDLE_LOADED);
ce7c191b	238	clear_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags);
ce8ab854 AB	239	spu_release(ctx);
	240
	241	if (signal_pending(current))
	242	ret = -ERESTARTSYS;
2ebb2477	243
ce8ab854 AB	244	return ret;
	245	}
	246
2dd14934 AB	247	/*
	248	* SPU syscall restarting is tricky because we violate the basic
	249	* assumption that the signal handler is running on the interrupted
	250	* thread. Here instead, the handler runs on PowerPC user space code,
	251	* while the syscall was called from the SPU.
	252	* This means we can only do a very rough approximation of POSIX
	253	* signal semantics.
	254	*/
1238819a	255	static int spu_handle_restartsys(struct spu_context ctx, long spu_ret,
2dd14934 AB	256	unsigned int *npc)
	257	{
	258	int ret;
	259
	260	switch (*spu_ret) {
	261	case -ERESTARTSYS:
	262	case -ERESTARTNOINTR:
	263	/*
	264	* Enter the regular syscall restarting for
	265	* sys_spu_run, then restart the SPU syscall
	266	* callback.
	267	*/
	268	*npc -= 8;
	269	ret = -ERESTARTSYS;
	270	break;
	271	case -ERESTARTNOHAND:
	272	case -ERESTART_RESTARTBLOCK:
	273	/*
	274	* Restart block is too hard for now, just return -EINTR
	275	* to the SPU.
	276	* ERESTARTNOHAND comes from sys_pause, we also return
	277	* -EINTR from there.
	278	* Assume that we need to be restarted ourselves though.
	279	*/
	280	*spu_ret = -EINTR;
	281	ret = -ERESTARTSYS;
	282	break;
	283	default:
	284	printk(KERN_WARNING "%s: unexpected return code %ld\n",
e48b1b45	285	__func__, *spu_ret);
2dd14934 AB	286	ret = 0;
	287	}
	288	return ret;
	289	}
	290
1238819a	291	static int spu_process_callback(struct spu_context *ctx)
2dd14934 AB	292	{
	293	struct spu_syscall_block s;
	294	u32 ls_pointer, npc;
9e2fe2ce	295	void __iomem *ls;
2dd14934	296	long spu_ret;
c9101bdb	297	int ret, ret2;
2dd14934 AB	298
2dd14934 AB	299	/* get syscall block from local store */
9e2fe2ce AM	300	npc = ctx->ops->npc_read(ctx) & ~3;
	301	ls = (void __iomem *)ctx->ops->get_ls(ctx);
	302	ls_pointer = in_be32(ls + npc);
2dd14934 AB	303	if (ls_pointer > (LS_SIZE - sizeof(s)))
2dd14934 AB	304	return -EFAULT;
9e2fe2ce	305	memcpy_fromio(&s, ls + ls_pointer, sizeof(s));
2dd14934 AB	306
	307	/* do actual syscall without pinning the spu */
	308	ret = 0;
	309	spu_ret = -ENOSYS;
	310	npc += 4;
	311
	312	if (s.nr_ret < __NR_syscalls) {
	313	spu_release(ctx);
	314	/* do actual system call from here */
	315	spu_ret = spu_sys_callback(&s);
	316	if (spu_ret <= -ERESTARTSYS) {
	317	ret = spu_handle_restartsys(ctx, &spu_ret, &npc);
	318	}
c9101bdb	319	ret2 = spu_acquire(ctx);
2dd14934 AB	320	if (ret == -ERESTARTSYS)
2dd14934 AB	321	return ret;
c9101bdb CH	322	if (ret2)
c9101bdb CH	323	return -EINTR;
2dd14934 AB	324	}
2dd14934 AB	325
4eb5aef5 JK	326	/* need to re-get the ls, as it may have changed when we released the
	327	* spu */
	328	ls = (void __iomem *)ctx->ops->get_ls(ctx);
	329
2dd14934	330	/* write result, jump over indirect pointer */
9e2fe2ce	331	memcpy_toio(ls + ls_pointer, &spu_ret, sizeof(spu_ret));
2dd14934 AB	332	ctx->ops->npc_write(ctx, npc);
	333	ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);
	334	return ret;
	335	}
	336
50af32a9	337	long spufs_run_spu(struct spu_context ctx, u32 npc, u32 *event)
ce8ab854 AB	338	{
ce8ab854 AB	339	int ret;
36aaccc1	340	struct spu *spu;
9add11da	341	u32 status;
ce8ab854	342
e45d48a3	343	if (mutex_lock_interruptible(&ctx->run_mutex))
ce8ab854 AB	344	return -ERESTARTSYS;
ce8ab854 AB	345
c25620d7	346	spu_enable_spu(ctx);
9add11da	347	ctx->event_return = 0;
aa45e256	348
c9101bdb CH	349	ret = spu_acquire(ctx);
	350	if (ret)
	351	goto out_unlock;
2cf2b3b4	352
91569531	353	spu_update_sched_info(ctx);
aa45e256 CH	354
	355	ret = spu_run_init(ctx, npc);
	356	if (ret) {
	357	spu_release(ctx);
ce8ab854	358	goto out;
aa45e256	359	}
ce8ab854 AB	360
ce8ab854 AB	361	do {
9add11da	362	ret = spufs_wait(ctx->stop_wq, spu_stopped(ctx, &status));
eebead5b CH	363	if (unlikely(ret)) {
	364	/*
	365	* This is nasty: we need the state_mutex for all the
	366	* bookkeeping even if the syscall was interrupted by
	367	* a signal. ewww.
	368	*/
	369	mutex_lock(&ctx->state_mutex);
ce8ab854	370	break;
eebead5b	371	}
36aaccc1 BN	372	spu = ctx->spu;
	373	if (unlikely(test_and_clear_bit(SPU_SCHED_NOTIFY_ACTIVE,
	374	&ctx->sched_flags))) {
	375	if (!(status & SPU_STATUS_STOPPED_BY_STOP)) {
	376	spu_switch_notify(spu, ctx);
	377	continue;
	378	}
	379	}
27ec41d3 AD	380
	381	spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
	382
9add11da AB	383	if ((status & SPU_STATUS_STOPPED_BY_STOP) &&
9add11da AB	384	(status >> SPU_STOP_STATUS_SHIFT == 0x2104)) {
2dd14934 AB	385	ret = spu_process_callback(ctx);
	386	if (ret)
	387	break;
9add11da	388	status &= ~SPU_STATUS_STOPPED_BY_STOP;
2dd14934	389	}
57dace23 AB	390	ret = spufs_handle_class1(ctx);
	391	if (ret)
	392	break;
	393
d6ad39bc JK	394	ret = spufs_handle_class0(ctx);
	395	if (ret)
	396	break;
	397
d6ad39bc JK	398	if (signal_pending(current))
d6ad39bc JK	399	ret = -ERESTARTSYS;
9add11da	400	} while (!ret && !(status & (SPU_STATUS_STOPPED_BY_STOP \|
05169237 BH	401	SPU_STATUS_STOPPED_BY_HALT \|
05169237 BH	402	SPU_STATUS_SINGLE_STEP)));
ce8ab854	403
c25620d7	404	spu_disable_spu(ctx);
9add11da	405	ret = spu_run_fini(ctx, npc, &status);
ce8ab854 AB	406	spu_yield(ctx);
ce8ab854 AB	407
5158e9b5 CH	408	spu_switch_log_notify(NULL, ctx, SWITCH_LOG_EXIT, status);
5158e9b5 CH	409
e66686b4 LB	410	if ((status & SPU_STATUS_STOPPED_BY_STOP) &&
	411	(((status >> SPU_STOP_STATUS_SHIFT) & 0x3f00) == 0x2100))
	412	ctx->stats.libassist++;
	413
2ebb2477 MN	414	if ((ret == 0) \|\|
	415	((ret == -ERESTARTSYS) &&
	416	((status & SPU_STATUS_STOPPED_BY_HALT) \|\|
05169237	417	(status & SPU_STATUS_SINGLE_STEP) \|\|
2ebb2477 MN	418	((status & SPU_STATUS_STOPPED_BY_STOP) &&
	419	(status >> SPU_STOP_STATUS_SHIFT != 0x2104)))))
	420	ret = status;
	421
05169237 BH	422	/* Note: we don't need to force_sig SIGTRAP on single-step
	423	* since we have TIF_SINGLESTEP set, thus the kernel will do
	424	* it upon return from the syscall anyawy
	425	*/
60cf54db JK	426	if (unlikely(status & SPU_STATUS_SINGLE_STEP))
	427	ret = -ERESTARTSYS;
	428
	429	else if (unlikely((status & SPU_STATUS_STOPPED_BY_STOP)
	430	&& (status >> SPU_STOP_STATUS_SHIFT) == 0x3fff)) {
c2b2226c AB	431	force_sig(SIGTRAP, current);
c2b2226c AB	432	ret = -ERESTARTSYS;
2ebb2477 MN	433	}
2ebb2477 MN	434
ce8ab854	435	out:
9add11da	436	*event = ctx->event_return;
c9101bdb	437	out_unlock:
e45d48a3	438	mutex_unlock(&ctx->run_mutex);
ce8ab854 AB	439	return ret;
ce8ab854 AB	440	}