1 files changed, 18 insertions, 155 deletions

diff --git a/arch/powerpc/platforms/powernv/vas-fault.c b/arch/powerpc/platforms/powernv/vas-fault.c
index 3d21fce254b7..a7aabc18039e 100644
--- a/arch/powerpc/platforms/powernv/vas-fault.c
+++ b/arch/powerpc/platforms/powernv/vas-fault.c
@@ -26,150 +26,6 @@
  */
 #define VAS_FAULT_WIN_FIFO_SIZE	(4 << 20)
 
-static void dump_crb(struct coprocessor_request_block *crb)
-{
-	struct data_descriptor_entry *dde;
-	struct nx_fault_stamp *nx;
-
-	dde = &crb->source;
-	pr_devel("SrcDDE: addr 0x%llx, len %d, count %d, idx %d, flags %d\n",
-		be64_to_cpu(dde->address), be32_to_cpu(dde->length),
-		dde->count, dde->index, dde->flags);
-
-	dde = &crb->target;
-	pr_devel("TgtDDE: addr 0x%llx, len %d, count %d, idx %d, flags %d\n",
-		be64_to_cpu(dde->address), be32_to_cpu(dde->length),
-		dde->count, dde->index, dde->flags);
-
-	nx = &crb->stamp.nx;
-	pr_devel("NX Stamp: PSWID 0x%x, FSA 0x%llx, flags 0x%x, FS 0x%x\n",
-		be32_to_cpu(nx->pswid),
-		be64_to_cpu(crb->stamp.nx.fault_storage_addr),
-		nx->flags, nx->fault_status);
-}
-
-/*
- * Update the CSB to indicate a translation error.
- *
- * User space will be polling on CSB after the request is issued.
- * If NX can handle the request without any issues, it updates CSB.
- * Whereas if NX encounters page fault, the kernel will handle the
- * fault and update CSB with translation error.
- *
- * If we are unable to update the CSB means copy_to_user failed due to
- * invalid csb_addr, send a signal to the process.
- */
-static void update_csb(struct vas_window *window,
-			struct coprocessor_request_block *crb)
-{
-	struct coprocessor_status_block csb;
-	struct kernel_siginfo info;
-	struct task_struct *tsk;
-	void __user *csb_addr;
-	struct pid *pid;
-	int rc;
-
-	/*
-	 * NX user space windows can not be opened for task->mm=NULL
-	 * and faults will not be generated for kernel requests.
-	 */
-	if (WARN_ON_ONCE(!window->mm || !window->user_win))
-		return;
-
-	csb_addr = (void __user *)be64_to_cpu(crb->csb_addr);
-
-	memset(&csb, 0, sizeof(csb));
-	csb.cc = CSB_CC_FAULT_ADDRESS;
-	csb.ce = CSB_CE_TERMINATION;
-	csb.cs = 0;
-	csb.count = 0;
-
-	/*
-	 * NX operates and returns in BE format as defined CRB struct.
-	 * So saves fault_storage_addr in BE as NX pastes in FIFO and
-	 * expects user space to convert to CPU format.
-	 */
-	csb.address = crb->stamp.nx.fault_storage_addr;
-	csb.flags = 0;
-
-	pid = window->pid;
-	tsk = get_pid_task(pid, PIDTYPE_PID);
-	/*
-	 * Process closes send window after all pending NX requests are
-	 * completed. In multi-thread applications, a child thread can
-	 * open a window and can exit without closing it. May be some
-	 * requests are pending or this window can be used by other
-	 * threads later. We should handle faults if NX encounters
-	 * pages faults on these requests. Update CSB with translation
-	 * error and fault address. If csb_addr passed by user space is
-	 * invalid, send SEGV signal to pid saved in window. If the
-	 * child thread is not running, send the signal to tgid.
-	 * Parent thread (tgid) will close this window upon its exit.
-	 *
-	 * pid and mm references are taken when window is opened by
-	 * process (pid). So tgid is used only when child thread opens
-	 * a window and exits without closing it.
-	 */
-	if (!tsk) {
-		pid = window->tgid;
-		tsk = get_pid_task(pid, PIDTYPE_PID);
-		/*
-		 * Parent thread (tgid) will be closing window when it
-		 * exits. So should not get here.
-		 */
-		if (WARN_ON_ONCE(!tsk))
-			return;
-	}
-
-	/* Return if the task is exiting. */
-	if (tsk->flags & PF_EXITING) {
-		put_task_struct(tsk);
-		return;
-	}
-
-	kthread_use_mm(window->mm);
-	rc = copy_to_user(csb_addr, &csb, sizeof(csb));
-	/*
-	 * User space polls on csb.flags (first byte). So add barrier
-	 * then copy first byte with csb flags update.
-	 */
-	if (!rc) {
-		csb.flags = CSB_V;
-		/* Make sure update to csb.flags is visible now */
-		smp_mb();
-		rc = copy_to_user(csb_addr, &csb, sizeof(u8));
-	}
-	kthread_unuse_mm(window->mm);
-	put_task_struct(tsk);
-
-	/* Success */
-	if (!rc)
-		return;
-
-	pr_debug("Invalid CSB address 0x%p signalling pid(%d)\n",
-			csb_addr, pid_vnr(pid));
-
-	clear_siginfo(&info);
-	info.si_signo = SIGSEGV;
-	info.si_errno = EFAULT;
-	info.si_code = SEGV_MAPERR;
-	info.si_addr = csb_addr;
-
-	/*
-	 * process will be polling on csb.flags after request is sent to
-	 * NX. So generally CSB update should not fail except when an
-	 * application passes invalid csb_addr. So an error message will
-	 * be displayed and leave it to user space whether to ignore or
-	 * handle this signal.
-	 */
-	rcu_read_lock();
-	rc = kill_pid_info(SIGSEGV, &info, pid);
-	rcu_read_unlock();
-
-	pr_devel("%s(): pid %d kill_proc_info() rc %d\n", __func__,
-			pid_vnr(pid), rc);
-}
-
 static void dump_fifo(struct vas_instance *vinst, void *entry)
 {
 	unsigned long *end = vinst->fault_fifo + vinst->fault_fifo_size;
@@ -212,7 +68,7 @@ irqreturn_t vas_fault_thread_fn(int irq, void *data)
 	struct vas_instance *vinst = data;
 	struct coprocessor_request_block *crb, *entry;
 	struct coprocessor_request_block buf;
-	struct vas_window *window;
+	struct pnv_vas_window *window;
 	unsigned long flags;
 	void *fifo;
 
@@ -272,7 +128,7 @@ irqreturn_t vas_fault_thread_fn(int irq, void *data)
 				vinst->vas_id, vinst->fault_fifo, fifo,
 				vinst->fault_crbs);
 
-		dump_crb(crb);
+		vas_dump_crb(crb);
 		window = vas_pswid_to_window(vinst,
 				be32_to_cpu(crb->stamp.nx.pswid));
 
@@ -293,7 +149,14 @@ irqreturn_t vas_fault_thread_fn(int irq, void *data)
 
 			WARN_ON_ONCE(1);
 		} else {
-			update_csb(window, crb);
+			/*
+			 * NX sees faults only with user space windows.
+			 */
+			if (window->user_win)
+				vas_update_csb(crb, &window->vas_win.task_ref);
+			else
+				WARN_ON_ONCE(!window->user_win);
+
 			/*
 			 * Return credit for send window after processing
 			 * fault CRB.
@@ -336,6 +199,7 @@ irqreturn_t vas_fault_handler(int irq, void *dev_id)
 int vas_setup_fault_window(struct vas_instance *vinst)
 {
 	struct vas_rx_win_attr attr;
+	struct vas_window *win;
 
 	vinst->fault_fifo_size = VAS_FAULT_WIN_FIFO_SIZE;
 	vinst->fault_fifo = kzalloc(vinst->fault_fifo_size, GFP_KERNEL);
@@ -364,18 +228,17 @@ int vas_setup_fault_window(struct vas_instance *vinst)
 	attr.lnotify_pid = mfspr(SPRN_PID);
 	attr.lnotify_tid = mfspr(SPRN_PID);
 
-	vinst->fault_win = vas_rx_win_open(vinst->vas_id, VAS_COP_TYPE_FAULT,
-					&attr);
-
-	if (IS_ERR(vinst->fault_win)) {
-		pr_err("VAS: Error %ld opening FaultWin\n",
-			PTR_ERR(vinst->fault_win));
+	win = vas_rx_win_open(vinst->vas_id, VAS_COP_TYPE_FAULT, &attr);
+	if (IS_ERR(win)) {
+		pr_err("VAS: Error %ld opening FaultWin\n", PTR_ERR(win));
 		kfree(vinst->fault_fifo);
-		return PTR_ERR(vinst->fault_win);
+		return PTR_ERR(win);
 	}
 
+	vinst->fault_win = container_of(win, struct pnv_vas_window, vas_win);
+
 	pr_devel("VAS: Created FaultWin %d, LPID/PID/TID [%d/%d/%d]\n",
-			vinst->fault_win->winid, attr.lnotify_lpid,
+			vinst->fault_win->vas_win.winid, attr.lnotify_lpid,
 			attr.lnotify_pid, attr.lnotify_tid);
 
 	return 0;