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

// SPDX-License-Identifier: GPL-2.0
#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, int irq)
{
	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 */
		switch(irq) {
		case 0 :
			ctx->csa.class_0_pending = spu->class_0_pending;
			ctx->csa.class_0_dar = spu->class_0_dar;
			break;
		case 1 :
			ctx->csa.class_1_dsisr = spu->class_1_dsisr;
			ctx->csa.class_1_dar = spu->class_1_dar;
			break;
		case 2 :
			break;
		}

		/* 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);
	}
}

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

	stopped = SPU_STATUS_INVALID_INSTR | SPU_STATUS_SINGLE_STEP |
		SPU_STATUS_STOPPED_BY_HALT | SPU_STATUS_STOPPED_BY_STOP;

top:
	*stat = ctx->ops->status_read(ctx);
	if (*stat & stopped) {
		/*
		 * If the spu hasn't finished stopping, we need to
		 * re-read the register to get the stopped value.
		 */
		if (*stat & SPU_STATUS_RUNNING)
			goto top;
		return 1;
	}

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

	dsisr = ctx->csa.class_1_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();
	}

	/* clear purge status */
	out_be64(mfc_cntl, 0);

	/* 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;
	} else {
		unsigned long privcntl;

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

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

	ctx->ops->runcntl_write(ctx, runcntl);

	if (ctx->flags & SPU_CREATE_NOSCHED) {
		spuctx_switch_state(ctx, SPU_UTIL_USER);
	} else {

		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_switch_log_notify(NULL, ctx, SWITCH_LOG_EXIT, *status);
	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;

	/* 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);
		}
		mutex_lock(&ctx->state_mutex);
		if (ret == -ERESTARTSYS)
			return ret;
	}

	/* 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;

	ctx->event_return = 0;

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

	spu_enable_spu(ctx);

	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);

	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 anyway.
	 */
	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
b2441318	1	// SPDX-License-Identifier: GPL-2.0
0afacde3	2	#define DEBUG
0afacde3	3
ce8ab854 AB	4	#include <linux/wait.h>
	5	#include <linux/ptrace.h>
	6
	7	#include <asm/spu.h>
c6730ed4 JK	8	#include <asm/spu_priv1.h>
c6730ed4 JK	9	#include <asm/io.h>
cfff5b23	10	#include <asm/unistd.h>
ce8ab854 AB	11
	12	#include "spufs.h"
	13
	14	/* interrupt-level stop callback function. */
f3d69e05	15	void spufs_stop_callback(struct spu *spu, int irq)
ce8ab854 AB	16	{
	17	struct spu_context *ctx = spu->ctx;
	18
d6ad39bc JK	19	/*
	20	* It should be impossible to preempt a context while an exception
	21	* is being processed, since the context switch code is specially
	22	* coded to deal with interrupts ... But, just in case, sanity check
	23	* the context pointer. It is OK to return doing nothing since
	24	* the exception will be regenerated when the context is resumed.
	25	*/
	26	if (ctx) {
	27	/* Copy exception arguments into module specific structure */
f3d69e05 LB	28	switch(irq) {
	29	case 0 :
	30	ctx->csa.class_0_pending = spu->class_0_pending;
f3d69e05 LB	31	ctx->csa.class_0_dar = spu->class_0_dar;
	32	break;
	33	case 1 :
	34	ctx->csa.class_1_dsisr = spu->class_1_dsisr;
	35	ctx->csa.class_1_dar = spu->class_1_dar;
	36	break;
	37	case 2 :
	38	break;
	39	}
d6ad39bc JK	40
	41	/* ensure that the exception status has hit memory before a
	42	* thread waiting on the context's stop queue is woken */
	43	smp_wmb();
	44
	45	wake_up_all(&ctx->stop_wq);
	46	}
ce8ab854 AB	47	}
ce8ab854 AB	48
e65c2f6f	49	int spu_stopped(struct spu_context ctx, u32 stat)
ce8ab854	50	{
e65c2f6f LB	51	u64 dsisr;
e65c2f6f LB	52	u32 stopped;
ce8ab854	53
d84050f4 LB	54	stopped = SPU_STATUS_INVALID_INSTR \| SPU_STATUS_SINGLE_STEP \|
d84050f4 LB	55	SPU_STATUS_STOPPED_BY_HALT \| SPU_STATUS_STOPPED_BY_STOP;
36aaccc1	56
d84050f4 LB	57	top:
	58	*stat = ctx->ops->status_read(ctx);
	59	if (*stat & stopped) {
	60	/*
	61	* If the spu hasn't finished stopping, we need to
	62	* re-read the register to get the stopped value.
	63	*/
	64	if (*stat & SPU_STATUS_RUNNING)
	65	goto top;
e65c2f6f	66	return 1;
d84050f4	67	}
e65c2f6f	68
d84050f4	69	if (test_bit(SPU_SCHED_NOTIFY_ACTIVE, &ctx->sched_flags))
e65c2f6f LB	70	return 1;
e65c2f6f LB	71
f3d69e05	72	dsisr = ctx->csa.class_1_dsisr;
e65c2f6f	73	if (dsisr & (MFC_DSISR_PTE_NOT_FOUND \| MFC_DSISR_ACCESS_DENIED))
36aaccc1	74	return 1;
e65c2f6f LB	75
	76	if (ctx->csa.class_0_pending)
	77	return 1;
	78
	79	return 0;
ce8ab854 AB	80	}
ce8ab854 AB	81
c6730ed4 JK	82	static int spu_setup_isolated(struct spu_context *ctx)
	83	{
	84	int ret;
	85	u64 __iomem *mfc_cntl;
	86	u64 sr1;
	87	u32 status;
	88	unsigned long timeout;
	89	const u32 status_loading = SPU_STATUS_RUNNING
	90	\| SPU_STATUS_ISOLATED_STATE \| SPU_STATUS_ISOLATED_LOAD_STATUS;
	91
7ec18ab9	92	ret = -ENODEV;
c6730ed4	93	if (!isolated_loader)
c6730ed4 JK	94	goto out;
c6730ed4 JK	95
7ec18ab9 CH	96	/*
	97	* We need to exclude userspace access to the context.
	98	*
	99	* To protect against memory access we invalidate all ptes
	100	* and make sure the pagefault handlers block on the mutex.
	101	*/
	102	spu_unmap_mappings(ctx);
	103
c6730ed4 JK	104	mfc_cntl = &ctx->spu->priv2->mfc_control_RW;
	105
	106	/* purge the MFC DMA queue to ensure no spurious accesses before we
	107	* enter kernel mode */
	108	timeout = jiffies + HZ;
	109	out_be64(mfc_cntl, MFC_CNTL_PURGE_DMA_REQUEST);
	110	while ((in_be64(mfc_cntl) & MFC_CNTL_PURGE_DMA_STATUS_MASK)
	111	!= MFC_CNTL_PURGE_DMA_COMPLETE) {
	112	if (time_after(jiffies, timeout)) {
	113	printk(KERN_ERR "%s: timeout flushing MFC DMA queue\n",
e48b1b45	114	__func__);
c6730ed4	115	ret = -EIO;
7ec18ab9	116	goto out;
c6730ed4 JK	117	}
	118	cond_resched();
	119	}
	120
3688b46b JK	121	/* clear purge status */
	122	out_be64(mfc_cntl, 0);
	123
c6730ed4 JK	124	/* put the SPE in kernel mode to allow access to the loader */
	125	sr1 = spu_mfc_sr1_get(ctx->spu);
	126	sr1 &= ~MFC_STATE1_PROBLEM_STATE_MASK;
	127	spu_mfc_sr1_set(ctx->spu, sr1);
	128
	129	/* start the loader */
	130	ctx->ops->signal1_write(ctx, (unsigned long)isolated_loader >> 32);
	131	ctx->ops->signal2_write(ctx,
	132	(unsigned long)isolated_loader & 0xffffffff);
	133
	134	ctx->ops->runcntl_write(ctx,
	135	SPU_RUNCNTL_RUNNABLE \| SPU_RUNCNTL_ISOLATE);
	136
	137	ret = 0;
	138	timeout = jiffies + HZ;
	139	while (((status = ctx->ops->status_read(ctx)) & status_loading) ==
	140	status_loading) {
	141	if (time_after(jiffies, timeout)) {
	142	printk(KERN_ERR "%s: timeout waiting for loader\n",
e48b1b45	143	__func__);
c6730ed4 JK	144	ret = -EIO;
	145	goto out_drop_priv;
	146	}
	147	cond_resched();
	148	}
	149
	150	if (!(status & SPU_STATUS_RUNNING)) {
	151	/* If isolated LOAD has failed: run SPU, we will get a stop-and
	152	* signal later. */
e48b1b45	153	pr_debug("%s: isolated LOAD failed\n", __func__);
c6730ed4 JK	154	ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);
c6730ed4 JK	155	ret = -EACCES;
7ec18ab9 CH	156	goto out_drop_priv;
7ec18ab9 CH	157	}
c6730ed4	158
7ec18ab9	159	if (!(status & SPU_STATUS_ISOLATED_STATE)) {
c6730ed4	160	/* This isn't allowed by the CBEA, but check anyway */
e48b1b45	161	pr_debug("%s: SPU fell out of isolated mode?\n", __func__);
c6730ed4 JK	162	ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_STOP);
c6730ed4 JK	163	ret = -EINVAL;
7ec18ab9	164	goto out_drop_priv;
c6730ed4 JK	165	}
	166
	167	out_drop_priv:
	168	/* Finished accessing the loader. Drop kernel mode */
	169	sr1 \|= MFC_STATE1_PROBLEM_STATE_MASK;
	170	spu_mfc_sr1_set(ctx->spu, sr1);
	171
c6730ed4 JK	172	out:
	173	return ret;
	174	}
	175
36aaccc1	176	static int spu_run_init(struct spu_context ctx, u32 npc)
ce8ab854	177	{
e65c2f6f	178	unsigned long runcntl = SPU_RUNCNTL_RUNNABLE;
91569531	179	int ret;
cc210b3e	180
27ec41d3 AD	181	spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
27ec41d3 AD	182
e65c2f6f LB	183	/*
	184	* NOSCHED is synchronous scheduling with respect to the caller.
	185	* The caller waits for the context to be loaded.
	186	*/
	187	if (ctx->flags & SPU_CREATE_NOSCHED) {
91569531	188	if (ctx->state == SPU_STATE_SAVED) {
91569531 LB	189	ret = spu_activate(ctx, 0);
	190	if (ret)
	191	return ret;
	192	}
e65c2f6f	193	}
aa45e256	194
e65c2f6f LB	195	/*
	196	* Apply special setup as required.
	197	*/
	198	if (ctx->flags & SPU_CREATE_ISOLATE) {
c6730ed4	199	if (!(ctx->ops->status_read(ctx) & SPU_STATUS_ISOLATED_STATE)) {
91569531	200	ret = spu_setup_isolated(ctx);
7ec18ab9	201	if (ret)
aa45e256	202	return ret;
c6730ed4 JK	203	}
c6730ed4 JK	204
91569531 LB	205	/*
	206	* If userspace has set the runcntrl register (eg, to
	207	* issue an isolated exit), we need to re-set it here
	208	*/
c6730ed4 JK	209	runcntl = ctx->ops->runcntl_read(ctx) &
	210	(SPU_RUNCNTL_RUNNABLE \| SPU_RUNCNTL_ISOLATE);
	211	if (runcntl == 0)
	212	runcntl = SPU_RUNCNTL_RUNNABLE;
2eb1b120	213	} else {
cc210b3e LB	214	unsigned long privcntl;
cc210b3e LB	215
05169237	216	if (test_thread_flag(TIF_SINGLESTEP))
cc210b3e LB	217	privcntl = SPU_PRIVCNTL_MODE_SINGLE_STEP;
	218	else
	219	privcntl = SPU_PRIVCNTL_MODE_NORMAL;
cc210b3e	220
cc210b3e	221	ctx->ops->privcntl_write(ctx, privcntl);
d9dd421f JK	222	ctx->ops->npc_write(ctx, *npc);
	223	}
	224
	225	ctx->ops->runcntl_write(ctx, runcntl);
	226
	227	if (ctx->flags & SPU_CREATE_NOSCHED) {
	228	spuctx_switch_state(ctx, SPU_UTIL_USER);
	229	} else {
c6730ed4	230
91569531	231	if (ctx->state == SPU_STATE_SAVED) {
91569531 LB	232	ret = spu_activate(ctx, 0);
	233	if (ret)
	234	return ret;
e65c2f6f LB	235	} else {
e65c2f6f LB	236	spuctx_switch_state(ctx, SPU_UTIL_USER);
91569531	237	}
91569531	238	}
27ec41d3	239
ce7c191b	240	set_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags);
aa45e256	241	return 0;
ce8ab854 AB	242	}
ce8ab854 AB	243
36aaccc1 BN	244	static int spu_run_fini(struct spu_context ctx, u32 npc,
36aaccc1 BN	245	u32 *status)
ce8ab854 AB	246	{
	247	int ret = 0;
	248
e65c2f6f LB	249	spu_del_from_rq(ctx);
e65c2f6f LB	250
ce8ab854 AB	251	*status = ctx->ops->status_read(ctx);
ce8ab854 AB	252	*npc = ctx->ops->npc_read(ctx);
27ec41d3 AD	253
27ec41d3 AD	254	spuctx_switch_state(ctx, SPU_UTIL_IDLE_LOADED);
ce7c191b	255	clear_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags);
f5ed0eb6	256	spu_switch_log_notify(NULL, ctx, SWITCH_LOG_EXIT, *status);
ce8ab854 AB	257	spu_release(ctx);
	258
	259	if (signal_pending(current))
	260	ret = -ERESTARTSYS;
2ebb2477	261
ce8ab854 AB	262	return ret;
	263	}
	264
2dd14934 AB	265	/*
	266	* SPU syscall restarting is tricky because we violate the basic
	267	* assumption that the signal handler is running on the interrupted
	268	* thread. Here instead, the handler runs on PowerPC user space code,
	269	* while the syscall was called from the SPU.
	270	* This means we can only do a very rough approximation of POSIX
	271	* signal semantics.
	272	*/
1238819a	273	static int spu_handle_restartsys(struct spu_context ctx, long spu_ret,
2dd14934 AB	274	unsigned int *npc)
	275	{
	276	int ret;
	277
	278	switch (*spu_ret) {
	279	case -ERESTARTSYS:
	280	case -ERESTARTNOINTR:
	281	/*
	282	* Enter the regular syscall restarting for
	283	* sys_spu_run, then restart the SPU syscall
	284	* callback.
	285	*/
	286	*npc -= 8;
	287	ret = -ERESTARTSYS;
	288	break;
	289	case -ERESTARTNOHAND:
	290	case -ERESTART_RESTARTBLOCK:
	291	/*
	292	* Restart block is too hard for now, just return -EINTR
	293	* to the SPU.
	294	* ERESTARTNOHAND comes from sys_pause, we also return
	295	* -EINTR from there.
	296	* Assume that we need to be restarted ourselves though.
	297	*/
	298	*spu_ret = -EINTR;
	299	ret = -ERESTARTSYS;
	300	break;
	301	default:
	302	printk(KERN_WARNING "%s: unexpected return code %ld\n",
e48b1b45	303	__func__, *spu_ret);
2dd14934 AB	304	ret = 0;
	305	}
	306	return ret;
	307	}
	308
1238819a	309	static int spu_process_callback(struct spu_context *ctx)
2dd14934 AB	310	{
	311	struct spu_syscall_block s;
	312	u32 ls_pointer, npc;
9e2fe2ce	313	void __iomem *ls;
2dd14934	314	long spu_ret;
d29694f0	315	int ret;
2dd14934 AB	316
2dd14934 AB	317	/* get syscall block from local store */
9e2fe2ce AM	318	npc = ctx->ops->npc_read(ctx) & ~3;
	319	ls = (void __iomem *)ctx->ops->get_ls(ctx);
	320	ls_pointer = in_be32(ls + npc);
2dd14934 AB	321	if (ls_pointer > (LS_SIZE - sizeof(s)))
2dd14934 AB	322	return -EFAULT;
9e2fe2ce	323	memcpy_fromio(&s, ls + ls_pointer, sizeof(s));
2dd14934 AB	324
	325	/* do actual syscall without pinning the spu */
	326	ret = 0;
	327	spu_ret = -ENOSYS;
	328	npc += 4;
	329
f43194e4	330	if (s.nr_ret < NR_syscalls) {
2dd14934 AB	331	spu_release(ctx);
	332	/* do actual system call from here */
	333	spu_ret = spu_sys_callback(&s);
	334	if (spu_ret <= -ERESTARTSYS) {
	335	ret = spu_handle_restartsys(ctx, &spu_ret, &npc);
	336	}
d29694f0	337	mutex_lock(&ctx->state_mutex);
2dd14934 AB	338	if (ret == -ERESTARTSYS)
	339	return ret;
	340	}
	341
4eb5aef5 JK	342	/* need to re-get the ls, as it may have changed when we released the
	343	* spu */
	344	ls = (void __iomem *)ctx->ops->get_ls(ctx);
	345
2dd14934	346	/* write result, jump over indirect pointer */
9e2fe2ce	347	memcpy_toio(ls + ls_pointer, &spu_ret, sizeof(spu_ret));
2dd14934 AB	348	ctx->ops->npc_write(ctx, npc);
	349	ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);
	350	return ret;
	351	}
	352
50af32a9	353	long spufs_run_spu(struct spu_context ctx, u32 npc, u32 *event)
ce8ab854 AB	354	{
ce8ab854 AB	355	int ret;
36aaccc1	356	struct spu *spu;
9add11da	357	u32 status;
ce8ab854	358
e45d48a3	359	if (mutex_lock_interruptible(&ctx->run_mutex))
ce8ab854 AB	360	return -ERESTARTSYS;
ce8ab854 AB	361
9add11da	362	ctx->event_return = 0;
aa45e256	363
c9101bdb CH	364	ret = spu_acquire(ctx);
	365	if (ret)
	366	goto out_unlock;
2cf2b3b4	367
c0bace5c JK	368	spu_enable_spu(ctx);
c0bace5c JK	369
91569531	370	spu_update_sched_info(ctx);
aa45e256 CH	371
	372	ret = spu_run_init(ctx, npc);
	373	if (ret) {
	374	spu_release(ctx);
ce8ab854	375	goto out;
aa45e256	376	}
ce8ab854 AB	377
ce8ab854 AB	378	do {
9add11da	379	ret = spufs_wait(ctx->stop_wq, spu_stopped(ctx, &status));
eebead5b CH	380	if (unlikely(ret)) {
	381	/*
	382	* This is nasty: we need the state_mutex for all the
	383	* bookkeeping even if the syscall was interrupted by
	384	* a signal. ewww.
	385	*/
	386	mutex_lock(&ctx->state_mutex);
ce8ab854	387	break;
eebead5b	388	}
36aaccc1 BN	389	spu = ctx->spu;
	390	if (unlikely(test_and_clear_bit(SPU_SCHED_NOTIFY_ACTIVE,
	391	&ctx->sched_flags))) {
	392	if (!(status & SPU_STATUS_STOPPED_BY_STOP)) {
	393	spu_switch_notify(spu, ctx);
	394	continue;
	395	}
	396	}
27ec41d3 AD	397
	398	spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
	399
9add11da AB	400	if ((status & SPU_STATUS_STOPPED_BY_STOP) &&
9add11da AB	401	(status >> SPU_STOP_STATUS_SHIFT == 0x2104)) {
2dd14934 AB	402	ret = spu_process_callback(ctx);
	403	if (ret)
	404	break;
9add11da	405	status &= ~SPU_STATUS_STOPPED_BY_STOP;
2dd14934	406	}
57dace23 AB	407	ret = spufs_handle_class1(ctx);
	408	if (ret)
	409	break;
	410
d6ad39bc JK	411	ret = spufs_handle_class0(ctx);
	412	if (ret)
	413	break;
	414
d6ad39bc JK	415	if (signal_pending(current))
d6ad39bc JK	416	ret = -ERESTARTSYS;
9add11da	417	} while (!ret && !(status & (SPU_STATUS_STOPPED_BY_STOP \|
05169237 BH	418	SPU_STATUS_STOPPED_BY_HALT \|
05169237 BH	419	SPU_STATUS_SINGLE_STEP)));
ce8ab854	420
c25620d7	421	spu_disable_spu(ctx);
9add11da	422	ret = spu_run_fini(ctx, npc, &status);
ce8ab854 AB	423	spu_yield(ctx);
ce8ab854 AB	424
e66686b4 LB	425	if ((status & SPU_STATUS_STOPPED_BY_STOP) &&
	426	(((status >> SPU_STOP_STATUS_SHIFT) & 0x3f00) == 0x2100))
	427	ctx->stats.libassist++;
	428
2ebb2477 MN	429	if ((ret == 0) \|\|
	430	((ret == -ERESTARTSYS) &&
	431	((status & SPU_STATUS_STOPPED_BY_HALT) \|\|
05169237	432	(status & SPU_STATUS_SINGLE_STEP) \|\|
2ebb2477 MN	433	((status & SPU_STATUS_STOPPED_BY_STOP) &&
	434	(status >> SPU_STOP_STATUS_SHIFT != 0x2104)))))
	435	ret = status;
	436
05169237 BH	437	/* Note: we don't need to force_sig SIGTRAP on single-step
05169237 BH	438	* since we have TIF_SINGLESTEP set, thus the kernel will do
027dfac6	439	* it upon return from the syscall anyway.
05169237	440	*/
60cf54db JK	441	if (unlikely(status & SPU_STATUS_SINGLE_STEP))
	442	ret = -ERESTARTSYS;
	443
	444	else if (unlikely((status & SPU_STATUS_STOPPED_BY_STOP)
	445	&& (status >> SPU_STOP_STATUS_SHIFT) == 0x3fff)) {
c2b2226c AB	446	force_sig(SIGTRAP, current);
c2b2226c AB	447	ret = -ERESTARTSYS;
2ebb2477 MN	448	}
2ebb2477 MN	449
ce8ab854	450	out:
9add11da	451	*event = ctx->event_return;
c9101bdb	452	out_unlock:
e45d48a3	453	mutex_unlock(&ctx->run_mutex);
ce8ab854 AB	454	return ret;
ce8ab854 AB	455	}