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#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;
}
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