aboutsummaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms/cell/spufs/run.c
blob: c04e078c0fe573dc41fc1576be4154d06dcc39f6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
#include <linux/wait.h>
#include <linux/ptrace.h>

#include <asm/spu.h>

#include "spufs.h"

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

	wake_up_all(&ctx->stop_wq);
}

static inline int spu_stopped(struct spu_context *ctx, u32 * stat)
{
	struct spu *spu;
	u64 pte_fault;

	*stat = ctx->ops->status_read(ctx);
	if (ctx->state != SPU_STATE_RUNNABLE)
		return 1;
	spu = ctx->spu;
	pte_fault = spu->dsisr &
	    (MFC_DSISR_PTE_NOT_FOUND | MFC_DSISR_ACCESS_DENIED);
	return (!(*stat & 0x1) || pte_fault || spu->class_0_pending) ? 1 : 0;
}

static inline int spu_run_init(struct spu_context *ctx, u32 * npc,
			       u32 * status)
{
	int ret;

	if ((ret = spu_acquire_runnable(ctx)) != 0)
		return ret;
	ctx->ops->npc_write(ctx, *npc);
	ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);
	return 0;
}

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

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

	if (signal_pending(current))
		ret = -ERESTARTSYS;
	if (unlikely(current->ptrace & PT_PTRACED)) {
		if ((*status & SPU_STATUS_STOPPED_BY_STOP)
		    && (*status >> SPU_STOP_STATUS_SHIFT) == 0x3fff) {
			force_sig(SIGTRAP, current);
			ret = -ERESTARTSYS;
		}
	}
	return ret;
}

static inline int spu_reacquire_runnable(struct spu_context *ctx, u32 *npc,
				         u32 *status)
{
	int ret;

	if ((ret = spu_run_fini(ctx, npc, status)) != 0)
		return ret;
	if (*status & (SPU_STATUS_STOPPED_BY_STOP |
		       SPU_STATUS_STOPPED_BY_HALT)) {
		return *status;
	}
	if ((ret = spu_run_init(ctx, npc, status)) != 0)
		return ret;
	return 0;
}

/*
 * 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.
 */
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",
			__FUNCTION__, *spu_ret);
		ret = 0;
	}
	return ret;
}

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

	/* get syscall block from local store */
	npc = ctx->ops->npc_read(ctx);
	ls = ctx->ops->get_ls(ctx);
	ls_pointer = *(u32*)(ls + npc);
	if (ls_pointer > (LS_SIZE - sizeof(s)))
		return -EFAULT;
	memcpy(&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);
		}
		spu_acquire(ctx);
		if (ret == -ERESTARTSYS)
			return ret;
	}

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

static inline int spu_process_events(struct spu_context *ctx)
{
	struct spu *spu = ctx->spu;
	u64 pte_fault = MFC_DSISR_PTE_NOT_FOUND | MFC_DSISR_ACCESS_DENIED;
	int ret = 0;

	if (spu->dsisr & pte_fault)
		ret = spu_irq_class_1_bottom(spu);
	if (spu->class_0_pending)
		ret = spu_irq_class_0_bottom(spu);
	if (!ret && signal_pending(current))
		ret = -ERESTARTSYS;
	return ret;
}

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

	if (down_interruptible(&ctx->run_sema))
		return -ERESTARTSYS;

	ret = spu_run_init(ctx, npc, status);
	if (ret)
		goto out;

	do {
		ret = spufs_wait(ctx->stop_wq, spu_stopped(ctx, status));
		if (unlikely(ret))
			break;
		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;
		}
		if (unlikely(ctx->state != SPU_STATE_RUNNABLE)) {
			ret = spu_reacquire_runnable(ctx, npc, status);
			if (ret)
				goto out;
			continue;
		}
		ret = spu_process_events(ctx);

	} while (!ret && !(*status & (SPU_STATUS_STOPPED_BY_STOP |
				      SPU_STATUS_STOPPED_BY_HALT)));

	ctx->ops->runcntl_stop(ctx);
	ret = spu_run_fini(ctx, npc, status);
	if (!ret)
		ret = *status;
	spu_yield(ctx);

out:
	up(&ctx->run_sema);
	return ret;
}