gru: generic infrastructure for context options

Change the user GRU request for specifying the "task_slice" option to use
a generic infrastructure that can be expanded in the future to include
additional context options.  No new capabilities are added with this
patch.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/misc/sgi-gru/grufault.c

@@ -749,18 +749,30 @@ long gru_get_gseg_statistics(unsigned long arg)
  * Register the current task as the user of the GSEG slice.
  * Needed for TLB fault interrupt targeting.
  */
-int gru_set_task_slice(long address)
+int gru_set_context_option(unsigned long arg)
 {
 	struct gru_thread_state *gts;
+	struct gru_set_context_option_req req;
+	int ret = 0;
 
-	STAT(set_task_slice);
-	gru_dbg(grudev, "address 0x%lx\n", address);
-	gts = gru_alloc_locked_gts(address);
+	STAT(set_context_option);
+	if (copy_from_user(&req, (void __user *)arg, sizeof(req)))
+		return -EFAULT;
+	gru_dbg(grudev, "op %d, gseg 0x%lx, value1 0x%lx\n", req.op, req.gseg, req.val1);
+
+	gts = gru_alloc_locked_gts(req.gseg);
 	if (!gts)
 		return -EINVAL;
 
+	switch (req.op) {
+	case sco_gseg_owner:
+ 		/* Register the current task as the GSEG owner */
 		gts->ts_tgid_owner = current->tgid;
+		break;
+	default:
+		ret = -EINVAL;
+	}
 	gru_unlock_gts(gts);
 
-	return 0;
+	return ret;
 }

drivers/misc/sgi-gru/grufile.c

@@ -198,8 +198,8 @@ static long gru_file_unlocked_ioctl(struct file *file, unsigned int req,
 	case GRU_CREATE_CONTEXT:
 		err = gru_create_new_context(arg);
 		break;
-	case GRU_SET_TASK_SLICE:
-		err = gru_set_task_slice(arg);
+	case GRU_SET_CONTEXT_OPTION:
+		err = gru_set_context_option(arg);
 		break;
 	case GRU_USER_GET_EXCEPTION_DETAIL:
 		err = gru_get_exception_detail(arg);

drivers/misc/sgi-gru/grulib.h

@@ -32,8 +32,8 @@
 /* Set Number of Request Blocks */
 #define GRU_CREATE_CONTEXT		_IOWR(GRU_IOCTL_NUM, 1, void *)
 
-/* Register task as using the slice */
-#define GRU_SET_TASK_SLICE		_IOWR(GRU_IOCTL_NUM, 5, void *)
+/*  Set Context Options */
+#define GRU_SET_CONTEXT_OPTION		_IOWR(GRU_IOCTL_NUM, 4, void *)
 
 /* Fetch exception detail */
 #define GRU_USER_GET_EXCEPTION_DETAIL	_IOWR(GRU_IOCTL_NUM, 6, void *)
@@ -95,6 +95,16 @@ struct gru_unload_context_req {
 	unsigned long	gseg;
 };
 
+/*
+ * Structure used to set context options
+ */
+enum {sco_gseg_owner};
+struct gru_set_context_option_req {
+	unsigned long	gseg;
+	int		op;
+	unsigned long	val1;
+};
+
 /*
  * Structure used to pass TLB flush parameters to the driver
  */

drivers/misc/sgi-gru/gruprocfs.c

@@ -73,7 +73,7 @@ static int statistics_show(struct seq_file *s, void *p)
 	printstat(s, user_flush_tlb);
 	printstat(s, user_unload_context);
 	printstat(s, user_exception);
-	printstat(s, set_task_slice);
+	printstat(s, set_context_option);
 	printstat(s, migrate_check);
 	printstat(s, migrated_retarget);
 	printstat(s, migrated_unload);

drivers/misc/sgi-gru/grutables.h

@@ -198,7 +198,7 @@ struct gru_stats_s {
 	atomic_long_t user_flush_tlb;
 	atomic_long_t user_unload_context;
 	atomic_long_t user_exception;
-	atomic_long_t set_task_slice;
+	atomic_long_t set_context_option;
 	atomic_long_t migrate_check;
 	atomic_long_t migrated_retarget;
 	atomic_long_t migrated_unload;
@@ -649,7 +649,7 @@ extern int gru_handle_user_call_os(unsigned long address);
 extern int gru_user_flush_tlb(unsigned long arg);
 extern int gru_user_unload_context(unsigned long arg);
 extern int gru_get_exception_detail(unsigned long arg);
-extern int gru_set_task_slice(long address);
+extern int gru_set_context_option(unsigned long address);
 extern int gru_cpu_fault_map_id(void);
 extern struct vm_area_struct *gru_find_vma(unsigned long vaddr);
 extern void gru_flush_all_tlb(struct gru_state *gru);