gru: allow users to specify gru chiplet 3

This patch builds on the infrastructure introduced in the patches that
allow user specification of GRU blades & chiplets for context allocation.

This patch simplifies the algorithms for migrating GRU contexts between
blades.

No new functionality is introduced.
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

@@ -362,7 +362,7 @@ static int gru_try_dropin(struct gru_thread_state *gts,
 
 	if (!(gts->ts_sizeavail & GRU_SIZEAVAIL(pageshift))) {
 		gts->ts_sizeavail |= GRU_SIZEAVAIL(pageshift);
-		if (atomic || !gru_update_cch(gts, 0)) {
+		if (atomic || !gru_update_cch(gts)) {
 			gts->ts_force_cch_reload = 1;
 			goto failupm;
 		}
@@ -553,14 +553,12 @@ int gru_handle_user_call_os(unsigned long cb)
 	 */
 	if (gts->ts_gru && gts->ts_force_cch_reload) {
 		gts->ts_force_cch_reload = 0;
-		gru_update_cch(gts, 0);
+		gru_update_cch(gts);
 	}
 
 	ret = -EAGAIN;
 	cbrnum = thread_cbr_number(gts, ucbnum);
-	if (gts->ts_force_unload) {
-		gru_unload_context(gts, 1);
-	} else if (gts->ts_gru) {
+	if (gts->ts_gru) {
 		tfh = get_tfh_by_index(gts->ts_gru, cbrnum);
 		cbk = get_gseg_base_address_cb(gts->ts_gru->gs_gru_base_vaddr,
 				gts->ts_ctxnum, ucbnum);

drivers/misc/sgi-gru/grumain.c

@@ -551,7 +551,6 @@ void gru_unload_context(struct gru_thread_state *gts, int savestate)
 
 	if (cch_deallocate(cch))
 		BUG();
-	gts->ts_force_unload = 0;	/* ts_force_unload locked by CCH lock */
 	unlock_cch_handle(cch);
 
 	gru_free_gru_context(gts);
@@ -624,11 +623,8 @@ void gru_load_context(struct gru_thread_state *gts)
  * Update fields in an active CCH:
  * 	- retarget interrupts on local blade
  * 	- update sizeavail mask
- * 	- force a delayed context unload by clearing the CCH asids. This
- * 	  forces TLB misses for new GRU instructions. The context is unloaded
- * 	  when the next TLB miss occurs.
  */
-int gru_update_cch(struct gru_thread_state *gts, int force_unload)
+int gru_update_cch(struct gru_thread_state *gts)
 {
 	struct gru_context_configuration_handle *cch;
 	struct gru_state *gru = gts->ts_gru;
@@ -642,7 +638,6 @@ int gru_update_cch(struct gru_thread_state *gts, int force_unload)
 			goto exit;
 		if (cch_interrupt(cch))
 			BUG();
-		if (!force_unload) {
 		for (i = 0; i < 8; i++)
 			cch->sizeavail[i] = gts->ts_sizeavail;
 		gts->ts_tlb_int_select = gru_cpu_fault_map_id();
@@ -650,13 +645,6 @@ int gru_update_cch(struct gru_thread_state *gts, int force_unload)
 		cch->tfm_fault_bit_enable =
 		  (gts->ts_user_options == GRU_OPT_MISS_FMM_POLL
 		    || gts->ts_user_options == GRU_OPT_MISS_FMM_INTR);
-		} else {
-			for (i = 0; i < 8; i++)
-				cch->asid[i] = 0;
-			cch->tfm_fault_bit_enable = 0;
-			cch->tlb_int_enable = 0;
-			gts->ts_force_unload = 1;
-		}
 		if (cch_start(cch))
 			BUG();
 		ret = 1;
@@ -681,7 +669,7 @@ static int gru_retarget_intr(struct gru_thread_state *gts)
 
 	gru_dbg(grudev, "retarget from %d to %d\n", gts->ts_tlb_int_select,
 		gru_cpu_fault_map_id());
-	return gru_update_cch(gts, 0);
+	return gru_update_cch(gts);
 }
 
 /*

drivers/misc/sgi-gru/grutables.h

@@ -382,8 +382,6 @@ struct gru_thread_state {
 	char			ts_blade;	/* If >= 0, migrate context if
 						   ref from diferent blade */
 	char			ts_force_cch_reload;
-	char			ts_force_unload;/* force context to be unloaded
-						   after migration */
 	char			ts_cbr_idx[GRU_CBR_AU];/* CBR numbers of each
 							  allocated CB */
 	int			ts_data_valid;	/* Indicates if ts_gdata has
@@ -636,7 +634,7 @@ extern struct gru_state *gru_assign_gru_context(struct gru_thread_state *gts);
 extern void gru_load_context(struct gru_thread_state *gts);
 extern void gru_steal_context(struct gru_thread_state *gts);
 extern void gru_unload_context(struct gru_thread_state *gts, int savestate);
-extern int gru_update_cch(struct gru_thread_state *gts, int force_unload);
+extern int gru_update_cch(struct gru_thread_state *gts);
 extern void gts_drop(struct gru_thread_state *gts);
 extern void gru_tgh_flush_init(struct gru_state *gru);
 extern int gru_kservices_init(void);