1 // SPDX-License-Identifier: GPL-2.0
4 #include <linux/wait.h>
5 #include <linux/ptrace.h>
8 #include <asm/spu_priv1.h>
10 #include <asm/unistd.h>
14 /* interrupt-level stop callback function. */
15 void spufs_stop_callback(struct spu *spu, int irq)
17 struct spu_context *ctx = spu->ctx;
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.
27 /* Copy exception arguments into module specific structure */
30 ctx->csa.class_0_pending = spu->class_0_pending;
31 ctx->csa.class_0_dar = spu->class_0_dar;
34 ctx->csa.class_1_dsisr = spu->class_1_dsisr;
35 ctx->csa.class_1_dar = spu->class_1_dar;
41 /* ensure that the exception status has hit memory before a
42 * thread waiting on the context's stop queue is woken */
45 wake_up_all(&ctx->stop_wq);
49 int spu_stopped(struct spu_context *ctx, u32 *stat)
54 stopped = SPU_STATUS_INVALID_INSTR | SPU_STATUS_SINGLE_STEP |
55 SPU_STATUS_STOPPED_BY_HALT | SPU_STATUS_STOPPED_BY_STOP;
58 *stat = ctx->ops->status_read(ctx);
59 if (*stat & stopped) {
61 * If the spu hasn't finished stopping, we need to
62 * re-read the register to get the stopped value.
64 if (*stat & SPU_STATUS_RUNNING)
69 if (test_bit(SPU_SCHED_NOTIFY_ACTIVE, &ctx->sched_flags))
72 dsisr = ctx->csa.class_1_dsisr;
73 if (dsisr & (MFC_DSISR_PTE_NOT_FOUND | MFC_DSISR_ACCESS_DENIED))
76 if (ctx->csa.class_0_pending)
82 static int spu_setup_isolated(struct spu_context *ctx)
85 u64 __iomem *mfc_cntl;
88 unsigned long timeout;
89 const u32 status_loading = SPU_STATUS_RUNNING
90 | SPU_STATUS_ISOLATED_STATE | SPU_STATUS_ISOLATED_LOAD_STATUS;
97 * We need to exclude userspace access to the context.
99 * To protect against memory access we invalidate all ptes
100 * and make sure the pagefault handlers block on the mutex.
102 spu_unmap_mappings(ctx);
104 mfc_cntl = &ctx->spu->priv2->mfc_control_RW;
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",
121 /* clear purge status */
122 out_be64(mfc_cntl, 0);
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);
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);
134 ctx->ops->runcntl_write(ctx,
135 SPU_RUNCNTL_RUNNABLE | SPU_RUNCNTL_ISOLATE);
138 timeout = jiffies + HZ;
139 while (((status = ctx->ops->status_read(ctx)) & status_loading) ==
141 if (time_after(jiffies, timeout)) {
142 printk(KERN_ERR "%s: timeout waiting for loader\n",
150 if (!(status & SPU_STATUS_RUNNING)) {
151 /* If isolated LOAD has failed: run SPU, we will get a stop-and
153 pr_debug("%s: isolated LOAD failed\n", __func__);
154 ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);
159 if (!(status & SPU_STATUS_ISOLATED_STATE)) {
160 /* This isn't allowed by the CBEA, but check anyway */
161 pr_debug("%s: SPU fell out of isolated mode?\n", __func__);
162 ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_STOP);
168 /* Finished accessing the loader. Drop kernel mode */
169 sr1 |= MFC_STATE1_PROBLEM_STATE_MASK;
170 spu_mfc_sr1_set(ctx->spu, sr1);
176 static int spu_run_init(struct spu_context *ctx, u32 *npc)
178 unsigned long runcntl = SPU_RUNCNTL_RUNNABLE;
181 spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
184 * NOSCHED is synchronous scheduling with respect to the caller.
185 * The caller waits for the context to be loaded.
187 if (ctx->flags & SPU_CREATE_NOSCHED) {
188 if (ctx->state == SPU_STATE_SAVED) {
189 ret = spu_activate(ctx, 0);
196 * Apply special setup as required.
198 if (ctx->flags & SPU_CREATE_ISOLATE) {
199 if (!(ctx->ops->status_read(ctx) & SPU_STATUS_ISOLATED_STATE)) {
200 ret = spu_setup_isolated(ctx);
206 * If userspace has set the runcntrl register (eg, to
207 * issue an isolated exit), we need to re-set it here
209 runcntl = ctx->ops->runcntl_read(ctx) &
210 (SPU_RUNCNTL_RUNNABLE | SPU_RUNCNTL_ISOLATE);
212 runcntl = SPU_RUNCNTL_RUNNABLE;
214 unsigned long privcntl;
216 if (test_thread_flag(TIF_SINGLESTEP))
217 privcntl = SPU_PRIVCNTL_MODE_SINGLE_STEP;
219 privcntl = SPU_PRIVCNTL_MODE_NORMAL;
221 ctx->ops->privcntl_write(ctx, privcntl);
222 ctx->ops->npc_write(ctx, *npc);
225 ctx->ops->runcntl_write(ctx, runcntl);
227 if (ctx->flags & SPU_CREATE_NOSCHED) {
228 spuctx_switch_state(ctx, SPU_UTIL_USER);
231 if (ctx->state == SPU_STATE_SAVED) {
232 ret = spu_activate(ctx, 0);
236 spuctx_switch_state(ctx, SPU_UTIL_USER);
240 set_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags);
244 static int spu_run_fini(struct spu_context *ctx, u32 *npc,
249 spu_del_from_rq(ctx);
251 *status = ctx->ops->status_read(ctx);
252 *npc = ctx->ops->npc_read(ctx);
254 spuctx_switch_state(ctx, SPU_UTIL_IDLE_LOADED);
255 clear_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags);
256 spu_switch_log_notify(NULL, ctx, SWITCH_LOG_EXIT, *status);
259 if (signal_pending(current))
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
273 static int spu_handle_restartsys(struct spu_context *ctx, long *spu_ret,
280 case -ERESTARTNOINTR:
282 * Enter the regular syscall restarting for
283 * sys_spu_run, then restart the SPU syscall
289 case -ERESTARTNOHAND:
290 case -ERESTART_RESTARTBLOCK:
292 * Restart block is too hard for now, just return -EINTR
294 * ERESTARTNOHAND comes from sys_pause, we also return
296 * Assume that we need to be restarted ourselves though.
302 printk(KERN_WARNING "%s: unexpected return code %ld\n",
309 static int spu_process_callback(struct spu_context *ctx)
311 struct spu_syscall_block s;
317 /* get syscall block from local store */
318 npc = ctx->ops->npc_read(ctx) & ~3;
319 ls = (void __iomem *)ctx->ops->get_ls(ctx);
320 ls_pointer = in_be32(ls + npc);
321 if (ls_pointer > (LS_SIZE - sizeof(s)))
323 memcpy_fromio(&s, ls + ls_pointer, sizeof(s));
325 /* do actual syscall without pinning the spu */
330 if (s.nr_ret < NR_syscalls) {
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);
337 mutex_lock(&ctx->state_mutex);
338 if (ret == -ERESTARTSYS)
342 /* need to re-get the ls, as it may have changed when we released the
344 ls = (void __iomem *)ctx->ops->get_ls(ctx);
346 /* write result, jump over indirect pointer */
347 memcpy_toio(ls + ls_pointer, &spu_ret, sizeof(spu_ret));
348 ctx->ops->npc_write(ctx, npc);
349 ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE);
353 long spufs_run_spu(struct spu_context *ctx, u32 *npc, u32 *event)
359 if (mutex_lock_interruptible(&ctx->run_mutex))
362 ctx->event_return = 0;
364 ret = spu_acquire(ctx);
370 spu_update_sched_info(ctx);
372 ret = spu_run_init(ctx, npc);
379 ret = spufs_wait(ctx->stop_wq, spu_stopped(ctx, &status));
382 * This is nasty: we need the state_mutex for all the
383 * bookkeeping even if the syscall was interrupted by
386 mutex_lock(&ctx->state_mutex);
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);
398 spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
400 if ((status & SPU_STATUS_STOPPED_BY_STOP) &&
401 (status >> SPU_STOP_STATUS_SHIFT == 0x2104)) {
402 ret = spu_process_callback(ctx);
405 status &= ~SPU_STATUS_STOPPED_BY_STOP;
407 ret = spufs_handle_class1(ctx);
411 ret = spufs_handle_class0(ctx);
415 if (signal_pending(current))
417 } while (!ret && !(status & (SPU_STATUS_STOPPED_BY_STOP |
418 SPU_STATUS_STOPPED_BY_HALT |
419 SPU_STATUS_SINGLE_STEP)));
421 spu_disable_spu(ctx);
422 ret = spu_run_fini(ctx, npc, &status);
425 if ((status & SPU_STATUS_STOPPED_BY_STOP) &&
426 (((status >> SPU_STOP_STATUS_SHIFT) & 0x3f00) == 0x2100))
427 ctx->stats.libassist++;
430 ((ret == -ERESTARTSYS) &&
431 ((status & SPU_STATUS_STOPPED_BY_HALT) ||
432 (status & SPU_STATUS_SINGLE_STEP) ||
433 ((status & SPU_STATUS_STOPPED_BY_STOP) &&
434 (status >> SPU_STOP_STATUS_SHIFT != 0x2104)))))
437 /* Note: we don't need to force_sig SIGTRAP on single-step
438 * since we have TIF_SINGLESTEP set, thus the kernel will do
439 * it upon return from the syscall anyway.
441 if (unlikely(status & SPU_STATUS_SINGLE_STEP))
444 else if (unlikely((status & SPU_STATUS_STOPPED_BY_STOP)
445 && (status >> SPU_STOP_STATUS_SHIFT) == 0x3fff)) {
451 *event = ctx->event_return;
453 mutex_unlock(&ctx->run_mutex);