2 * Low-level SPU handling
4 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
6 * Author: Arnd Bergmann <arndb@de.ibm.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 #include <linux/sched.h>
26 #include <asm/spu_csa.h>
31 * Handle an SPE event, depending on context SPU_CREATE_EVENTS_ENABLED flag.
33 * If the context was created with events, we just set the return event.
34 * Otherwise, send an appropriate signal to the process.
36 static void spufs_handle_event(struct spu_context
*ctx
,
37 unsigned long ea
, int type
)
41 if (ctx
->flags
& SPU_CREATE_EVENTS_ENABLED
) {
42 ctx
->event_return
|= type
;
43 wake_up_all(&ctx
->stop_wq
);
47 memset(&info
, 0, sizeof(info
));
50 case SPE_EVENT_INVALID_DMA
:
51 info
.si_signo
= SIGBUS
;
52 info
.si_code
= BUS_OBJERR
;
54 case SPE_EVENT_SPE_DATA_STORAGE
:
55 info
.si_signo
= SIGSEGV
;
56 info
.si_addr
= (void __user
*)ea
;
57 info
.si_code
= SEGV_ACCERR
;
58 ctx
->ops
->restart_dma(ctx
);
60 case SPE_EVENT_DMA_ALIGNMENT
:
61 info
.si_signo
= SIGBUS
;
62 /* DAR isn't set for an alignment fault :( */
63 info
.si_code
= BUS_ADRALN
;
65 case SPE_EVENT_SPE_ERROR
:
66 info
.si_signo
= SIGILL
;
67 info
.si_addr
= (void __user
*)(unsigned long)
68 ctx
->ops
->npc_read(ctx
) - 4;
69 info
.si_code
= ILL_ILLOPC
;
74 force_sig_info(info
.si_signo
, &info
, current
);
77 int spufs_handle_class0(struct spu_context
*ctx
)
79 unsigned long stat
= ctx
->csa
.class_0_pending
& CLASS0_INTR_MASK
;
84 if (stat
& CLASS0_DMA_ALIGNMENT_INTR
)
85 spufs_handle_event(ctx
, ctx
->csa
.class_0_dar
,
86 SPE_EVENT_DMA_ALIGNMENT
);
88 if (stat
& CLASS0_INVALID_DMA_COMMAND_INTR
)
89 spufs_handle_event(ctx
, ctx
->csa
.class_0_dar
,
90 SPE_EVENT_INVALID_DMA
);
92 if (stat
& CLASS0_SPU_ERROR_INTR
)
93 spufs_handle_event(ctx
, ctx
->csa
.class_0_dar
,
96 ctx
->csa
.class_0_pending
= 0;
102 * bottom half handler for page faults, we can't do this from
103 * interrupt context, since we might need to sleep.
104 * we also need to give up the mutex so we can get scheduled
105 * out while waiting for the backing store.
107 * TODO: try calling hash_page from the interrupt handler first
108 * in order to speed up the easy case.
110 int spufs_handle_class1(struct spu_context
*ctx
)
112 u64 ea
, dsisr
, access
;
118 * dar and dsisr get passed from the registers
119 * to the spu_context, to this function, but not
120 * back to the spu if it gets scheduled again.
122 * if we don't handle the fault for a saved context
123 * in time, we can still expect to get the same fault
124 * the immediately after the context restore.
126 ea
= ctx
->csa
.class_1_dar
;
127 dsisr
= ctx
->csa
.class_1_dsisr
;
129 if (!(dsisr
& (MFC_DSISR_PTE_NOT_FOUND
| MFC_DSISR_ACCESS_DENIED
)))
132 spuctx_switch_state(ctx
, SPU_UTIL_IOWAIT
);
134 pr_debug("ctx %p: ea %016llx, dsisr %016llx state %d\n", ctx
, ea
,
137 ctx
->stats
.hash_flt
++;
138 if (ctx
->state
== SPU_STATE_RUNNABLE
)
139 ctx
->spu
->stats
.hash_flt
++;
141 /* we must not hold the lock when entering copro_handle_mm_fault */
144 access
= (_PAGE_PRESENT
| _PAGE_USER
);
145 access
|= (dsisr
& MFC_DSISR_ACCESS_PUT
) ? _PAGE_RW
: 0UL;
146 local_irq_save(flags
);
147 ret
= hash_page(ea
, access
, 0x300, dsisr
);
148 local_irq_restore(flags
);
150 /* hashing failed, so try the actual fault handler */
152 ret
= copro_handle_mm_fault(current
->mm
, ea
, dsisr
, &flt
);
155 * This is nasty: we need the state_mutex for all the bookkeeping even
156 * if the syscall was interrupted by a signal. ewww.
158 mutex_lock(&ctx
->state_mutex
);
161 * Clear dsisr under ctxt lock after handling the fault, so that
162 * time slicing will not preempt the context while the page fault
163 * handler is running. Context switch code removes mappings.
165 ctx
->csa
.class_1_dar
= ctx
->csa
.class_1_dsisr
= 0;
168 * If we handled the fault successfully and are in runnable
169 * state, restart the DMA.
170 * In case of unhandled error report the problem to user space.
173 if (flt
& VM_FAULT_MAJOR
)
174 ctx
->stats
.maj_flt
++;
176 ctx
->stats
.min_flt
++;
177 if (ctx
->state
== SPU_STATE_RUNNABLE
) {
178 if (flt
& VM_FAULT_MAJOR
)
179 ctx
->spu
->stats
.maj_flt
++;
181 ctx
->spu
->stats
.min_flt
++;
185 ctx
->ops
->restart_dma(ctx
);
187 spufs_handle_event(ctx
, ea
, SPE_EVENT_SPE_DATA_STORAGE
);
189 spuctx_switch_state(ctx
, SPU_UTIL_SYSTEM
);