static long afu_ioctl_start_work(struct cxl_context *ctx,
struct cxl_ioctl_start_work __user *uwork)
{
struct cxl_ioctl_start_work work;
u64 amr = 0;
int rc;
pr_devel("%s: pe: %i\n", __func__, ctx->pe);
/* Do this outside the status_mutex to avoid a circular dependency with
* the locking in cxl_mmap_fault() */
if (copy_from_user(&work, uwork,
sizeof(struct cxl_ioctl_start_work))) {
rc = -EFAULT;
goto out;
}
mutex_lock(&ctx->status_mutex);
if (ctx->status != OPENED) {
rc = -EIO;
goto out;
}
/*
* if any of the reserved fields are set or any of the unused
* flags are set it's invalid
*/
if (work.reserved1 || work.reserved2 || work.reserved3 ||
work.reserved4 || work.reserved5 || work.reserved6 ||
(work.flags & ~CXL_START_WORK_ALL)) {
rc = -EINVAL;
goto out;
}
if (!(work.flags & CXL_START_WORK_NUM_IRQS))
work.num_interrupts = ctx->afu->pp_irqs;
else if ((work.num_interrupts < ctx->afu->pp_irqs) ||
(work.num_interrupts > ctx->afu->irqs_max)) {
rc = -EINVAL;
goto out;
}
if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
goto out;
if (work.flags & CXL_START_WORK_AMR)
amr = work.amr & mfspr(SPRN_UAMOR);
ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);
/*
* Increment the mapped context count for adapter. This also checks
* if adapter_context_lock is taken.
*/
rc = cxl_adapter_context_get(ctx->afu->adapter);
if (rc) {
afu_release_irqs(ctx, ctx);
goto out;
}
/*
* We grab the PID here and not in the file open to allow for the case
* where a process (master, some daemon, etc) has opened the chardev on
* behalf of another process, so the AFU's mm gets bound to the process
* that performs this ioctl and not the process that opened the file.
* Also we grab the PID of the group leader so that if the task that
* has performed the attach operation exits the mm context of the
* process is still accessible.
*/
ctx->pid = get_task_pid(current, PIDTYPE_PID);
ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID);
trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,
amr))) {
afu_release_irqs(ctx, ctx);
cxl_adapter_context_put(ctx->afu->adapter);
put_pid(ctx->glpid);
put_pid(ctx->pid);
ctx->glpid = ctx->pid = NULL;
goto out;
}
ctx->status = STARTED;
rc = 0;
out:
mutex_unlock(&ctx->status_mutex);
return rc;
}
/*
* Start a context
* Code here similar to afu_ioctl_start_work().
*/
int cxl_start_context(struct cxl_context *ctx, u64 wed,
struct task_struct *task)
{
int rc = 0;
bool kernel = true;
pr_devel("%s: pe: %i\n", __func__, ctx->pe);
mutex_lock(&ctx->status_mutex);
if (ctx->status == STARTED)
goto out; /* already started */
/*
* Increment the mapped context count for adapter. This also checks
* if adapter_context_lock is taken.
*/
rc = cxl_adapter_context_get(ctx->afu->adapter);
if (rc)
goto out;
if (task) {
ctx->pid = get_task_pid(task, PIDTYPE_PID);
kernel = false;
/* acquire a reference to the task's mm */
ctx->mm = get_task_mm(current);
/* ensure this mm_struct can't be freed */
cxl_context_mm_count_get(ctx);
if (ctx->mm) {
/* decrement the use count from above */
mmput(ctx->mm);
/* make TLBIs for this context global */
mm_context_add_copro(ctx->mm);
}
}
/*
* Increment driver use count. Enables global TLBIs for hash
* and callbacks to handle the segment table
*/
cxl_ctx_get();
/* See the comment in afu_ioctl_start_work() */
smp_mb();
if ((rc = cxl_ops->attach_process(ctx, kernel, wed, 0))) {
put_pid(ctx->pid);
ctx->pid = NULL;
cxl_adapter_context_put(ctx->afu->adapter);
cxl_ctx_put();
if (task) {
cxl_context_mm_count_put(ctx);
if (ctx->mm)
mm_context_remove_copro(ctx->mm);
}
goto out;
}
ctx->status = STARTED;
out:
mutex_unlock(&ctx->status_mutex);
return rc;
}
