GRU Driver V3: fixes to resolve code review comments

[linux-2.6-omap-h63xx.git] / drivers / misc / sgi-gru / grumain.c

diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c
index aef6822cb80e51260833c6848be903cedc955f25..0eeb8dddd2f51396a85d726a8286f09b68348580 100644 (file)
--- a/drivers/misc/sgi-gru/grumain.c
+++ b/drivers/misc/sgi-gru/grumain.c
@@ -22,7 +22,7 @@
 #include "grutables.h"
 #include "gruhandles.h"
 
-unsigned long options __read_mostly;
+unsigned long gru_options __read_mostly;
 
 static struct device_driver gru_driver = {
        .name = "gru"
@@ -163,14 +163,14 @@ static unsigned long reserve_resources(unsigned long *p, int n, int mmax,
        return bits;
 }
 
-unsigned long reserve_gru_cb_resources(struct gru_state *gru, int cbr_au_count,
+unsigned long gru_reserve_cb_resources(struct gru_state *gru, int cbr_au_count,
                                       char *cbmap)
 {
        return reserve_resources(&gru->gs_cbr_map, cbr_au_count, GRU_CBR_AU,
                                 cbmap);
 }
 
-unsigned long reserve_gru_ds_resources(struct gru_state *gru, int dsr_au_count,
+unsigned long gru_reserve_ds_resources(struct gru_state *gru, int dsr_au_count,
                                       char *dsmap)
 {
        return reserve_resources(&gru->gs_dsr_map, dsr_au_count, GRU_DSR_AU,
@@ -182,10 +182,10 @@ static void reserve_gru_resources(struct gru_state *gru,
 {
        gru->gs_active_contexts++;
        gts->ts_cbr_map =
-           reserve_gru_cb_resources(gru, gts->ts_cbr_au_count,
+           gru_reserve_cb_resources(gru, gts->ts_cbr_au_count,
                                     gts->ts_cbr_idx);
        gts->ts_dsr_map =
-           reserve_gru_ds_resources(gru, gts->ts_dsr_au_count, NULL);
+           gru_reserve_ds_resources(gru, gts->ts_dsr_au_count, NULL);
 }
 
 static void free_gru_resources(struct gru_state *gru,
@@ -416,6 +416,7 @@ static void gru_free_gru_context(struct gru_thread_state *gts)
 
 /*
  * Prefetching cachelines help hardware performance.
+ * (Strictly a performance enhancement. Not functionally required).
  */
 static void prefetch_data(void *p, int num, int stride)
 {
@@ -746,6 +747,8 @@ again:
  * gru_nopage
  *
  * Map the user's GRU segment
+ *
+ *     Note: gru segments alway mmaped on GRU_GSEG_PAGESIZE boundaries.
  */
 int gru_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
@@ -757,6 +760,7 @@ int gru_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
                vma, vaddr, GSEG_BASE(vaddr));
        STAT(nopfn);
 
+       /* The following check ensures vaddr is a valid address in the VMA */
        gts = gru_find_thread_state(vma, TSID(vaddr, vma));
        if (!gts)
                return VM_FAULT_SIGBUS;
@@ -775,7 +779,7 @@ again:
        }
 
        if (!gts->ts_gru) {
-               while (!gru_assign_gru_context(gts)) {
+               if (!gru_assign_gru_context(gts)) {
                        mutex_unlock(&gts->ts_ctxlock);
                        preempt_enable();
                        schedule_timeout(GRU_ASSIGN_DELAY);  /* true hack ZZZ */